Method and device for transmitting and receiving channel state information in wireless communication system

Abstract

Disclosed are a method and device for transmitting and receiving channel state information in a wireless communication system. The method according to an embodiment of the present disclosure may comprise the steps in which: a UE receives configuration information related to SRS transmission from a base station, wherein the configuration information includes information about a first SRS port group and information about a second SRS port group; the UE transmits, to the base station, the SRS transmission for the first SRS port group and the second SRS port group on the basis of the configuration information; the UE receives a CSI-RS from the base station in a plurality of CSI-RS resources; and the UE transmits CSI derived by using the CSI-RS to the base station.

Description

Method and device for transmitting and receiving channel state information in a wireless communication system

[0001] The present disclosure relates to a wireless communication system, and more specifically, to a method and apparatus for transmitting and receiving channel state information (CSI) in a wireless communication system.

[0002] The 5th generation (5G) wireless communication system is a successor technology to 4G LTE (long term evolution) and is a new clean-slate type mobile communication system with characteristics such as high performance, low latency, and high availability. In the case of 5G NR (New Radio), all available spectrum resources can be utilized, ranging from low-frequency bands below 1 GHz to intermediate frequency bands between 1 GHz and 10 GHz, and high-frequency (or millimeter wave) bands above 24 GHz. Based on the foundational technology of 5G wireless communication, 6G wireless communication systems are being developed.

[0003] 6G wireless communication systems are being developed with the goal of (i) very high data rates per device, (ii) a very large number of connected devices, (iii) global connectivity, (iv) very low latency, (v) reduced energy consumption of battery-free IoT (internet of things) devices, (vi) ultra-reliable connectivity, and (vii) connected intelligence with machine learning capabilities. The vision of 6G systems can be seen in four aspects: intelligent connectivity, deep connectivity, holographic connectivity, and ubiquitous connectivity. Various technologies are being researched in consideration of the requirements for 6G systems, such as a peak data rate of 1 Tbps per device, an end-to-end (E2E) latency of 1ms, a maximum spectrum efficiency of 100 bps / Hz, support for mobility of 1000 km / h, satellite integration, artificial intelligence (AI), autonomous vehicles, extended reality (XR), and haptic communication.

[0004] The technical problem of the present disclosure is to provide a method and apparatus for transmitting and receiving channel state information based on a sounding reference signal port group.

[0005] The technical problems to be solved in this disclosure are not limited to those mentioned above, and other technical problems not mentioned will be clearly understood by those skilled in the art to which this disclosure belongs from the description below.

[0006] A method according to an aspect of the present disclosure may include: receiving configuration information related to the transmission of a sounding reference signal (SRS) from a base station by a user device (UE), wherein the configuration information includes information regarding a first SRS port group and information regarding a second SRS port group; transmitting the SRS transmission for the first SRS port group and the second SRS port group to the base station by the UE based on the configuration information; receiving CSI-RS from a plurality of CSI-RS resources by the UE; and transmitting a CSI derived using the CSI-RS to the base station by the UE. The CSI may include information related to a first codeword mapped to the first SRS port group and information related to a second codeword mapped to the second SRS port group.

[0007] A method according to a further aspect of the present disclosure may include: a step of transmitting configuration information related to the transmission of a sounding reference signal (SRS) to user equipment (UE) by a base station, wherein the configuration information includes information regarding a first SRS port group and information regarding a second SRS port group; a step of receiving the SRS transmission for the first SRS port group and the second SRS port group from the UE by the base station based on the configuration information; a step of transmitting CSI-RS from a plurality of CSI-RS resources to the UE by the base station; and a step of receiving a CSI derived from the CSI-RS from the UE by the base station. The CSI may include information related to a first codeword mapped to the first SRS port group and information related to a second codeword mapped to the second SRS port group.

[0008] According to an embodiment of the present disclosure, channel status information for each sub-channel of multiple panel (or receiving unit) terminals can be accurately obtained.

[0009] In addition, according to an embodiment of the present disclosure, by separating CSI-RS resource / port(s) for each receiving panel / receiving unit of the terminal, the base station can transmit CSI-RS with beamforming / power, etc., applied to each receiving panel / receiving unit.

[0010] The effects obtainable from the present disclosure are not limited to those mentioned above, and other unmentioned effects will be clearly understood by those skilled in the art to which the present disclosure belongs from the description below.

[0011] The accompanying drawings, which are included as part of the detailed description to aid in understanding the present disclosure, provide embodiments of the present disclosure and explain the technical features of the present disclosure together with the detailed description.

[0012] FIG. 1 illustrates an exemplary flexible network topology to which some examples of the present disclosure may be applied.

[0013] FIG. 2 illustrates an exemplary communication system to which some examples of the present disclosure may be applied.

[0014] FIG. 3 illustrates an exemplary wireless device to which some examples of the present disclosure may be applied.

[0015] FIG. 4 illustrates an exemplary communication procedure between a first node and a second node to which some examples of the present disclosure may be applied.

[0016] FIG. 5 illustrates an exemplary functional framework for AI / ML operations to which some examples of the present disclosure may be applied.

[0017] FIG. 6 illustrates an exemplary communication procedure based on an AI / ML model between a first node and a second node to which some examples of the present disclosure may be applied.

[0018] FIG. 7 shows an electromagnetic spectrum to which some examples of the present disclosure may be applied.

[0019] FIG. 8 illustrates an exemplary system information transmission / reception procedure to which some examples of the present disclosure may be applied.

[0020] FIG. 9 illustrates an exemplary beam management procedure to which some examples of the present disclosure may be applied.

[0021] FIG. 10 illustrates a low-complexity receiver in a wireless communication system to which the present disclosure may be applied.

[0022] FIG. 11 illustrates signaling between a base station and a UE having a low-complexity receiver in a wireless communication system to which the present disclosure may be applied.

[0023] FIG. 12 is a diagram illustrating the operation of a UE for a channel status information transmission and reception method according to one embodiment of the present disclosure.

[0024] FIG. 13 is a diagram illustrating the operation of a base station for a channel status information transmission and reception method according to one embodiment of the present disclosure.

[0025] Hereinafter, preferred embodiments according to the present disclosure will be described in detail with reference to the accompanying drawings. The detailed description disclosed below, together with the accompanying drawings, is intended to describe exemplary embodiments of the present disclosure and is not intended to represent the only embodiment in which the present disclosure may be practiced. The following detailed description includes specific details to provide a complete understanding of the present disclosure. However, those skilled in the art will know that the present disclosure may be practiced without such specific details.

[0026] In some cases, to avoid obscuring the concept of the present disclosure, known structures and devices may be omitted or illustrated in the form of a block diagram focusing on the core functions of each structure and device.

[0027] In the present disclosure, when a component is described as being “connected,” “combined,” or “joined” with another component, this may include not only a direct connection but also an indirect connection in which another component exists between them. Furthermore, in the present disclosure, the terms “comprising” or “having” specify the presence of the mentioned features, steps, actions, elements, and / or components, but do not exclude the presence or addition of one or more other features, steps, actions, elements, components, and / or groups thereof.

[0028] In the present disclosure, terms such as "first," "second," etc. are used solely for the purpose of distinguishing one component from another and are not used to limit the components, nor do they limit the order or importance of the components unless specifically stated otherwise. Accordingly, within the scope of the present disclosure, a first component in one embodiment may be referred to as a second component in another embodiment, and likewise, a second component in one embodiment may be referred to as a first component in another embodiment.

[0029] The terms used in this disclosure are for the description of specific embodiments and are not intended to limit the claims. As used in the description of embodiments and the appended claims, the singular form is intended to include the plural form unless the context clearly indicates otherwise.

[0030] In the present disclosure, "A or B" may mean "only A," "only B," or "both A and B." Alternatively, in the present disclosure, "A or B" may be interpreted as "A and / or B." For example, in the present disclosure, "A, B or C" may mean "only A," "only B," "only C," or "any combination of A, B and C."

[0031] A slash ( / ) or a comma used in the present disclosure may mean "and / or." For example, "A / B" may mean "A and / or B." Accordingly, "A / B" may mean "only A," "only B," or "both A and B." For example, "A, B, C" may mean "A, B or C."

[0032] In the present disclosure, "at least one of A and B" may mean "only A," "only B," or "both A and B." Additionally, in the present disclosure, the expressions "at least one of A or B" or "at least one of A and / or B" may be interpreted as synonymous with "at least one of A and B."

[0033] Additionally, in the present disclosure, "at least one of A, B and C" may mean "only A," "only B," "only C," or "any combination of A, B and C." Additionally, "at least one of A, B or C" or "at least one of A, B and / or C" may mean "at least one of A, B and C."

[0034] Additionally, parentheses used in this disclosure may mean "for example." Specifically, when indicated as "control information (PDCCH)," "PDCCH" may be described as an example of "control information." In other words, the "control information" of this disclosure is not limited to "PDCCH," and "PDCCH" may be described as an example of "control information." Furthermore, even when indicated as "control information (i.e., PDCCH)," "PDCCH" may be described as an example of "control information."

[0035] In the following explanation, '...when, if, in case of' can be replaced with '...based on'.

[0036] Technical features described individually within one drawing in this disclosure may be implemented individually or simultaneously.

[0037] In the present disclosure, a terminal or user equipment (UE) may be a portable device and may be a first node that receives a signal from a base station / second node / integrated access backhaul (IAB) node.

[0038] In the present disclosure, the base station (BS) may be a second node / IAB node / Transmission-Reception Point (TRP).

[0039] In the present disclosure, a higher layer parameter may be a parameter configured, pre-configured, or pre-defined for a terminal. For example, a base station or network may transmit the higher layer parameter to the terminal. For example, the higher layer parameter may be transmitted via radio resource control (RRC) signaling or medium access control (MAC) signaling.

[0040] In the present disclosure, "set or defined" may be interpreted as being set to a device through predefined signaling (e.g., System Information Block (SIB), MAC, RRC) from a base station or network. In the present disclosure, "set or defined" may be interpreted as being set to a device through separate signaling or being predefined without separate signaling.

[0041] In the present disclosure, transmitting or receiving a channel includes the meaning of transmitting or receiving information or a signal through said channel. For example, transmitting a control channel means transmitting control information or a signal through the control channel. Similarly, transmitting a data channel means transmitting data information or a signal through the data channel.

[0042] The technology described in this disclosure can be used in various wireless communication systems such as CDMA (code division multiple access), FDMA (frequency division multiple access), TDMA (time division multiple access), OFDMA (orthogonal frequency division multiple access), and SC-FDMA (single carrier frequency division multiple access). CDMA can be implemented with wireless technologies such as UTRA (universal terrestrial radio access) or CDMA2000. TDMA can be implemented with wireless technologies such as GSM (global system for mobile communications), GPRS (general packet radio service), and EDGE (enhanced data rates for GSM evolution). OFDMA can be implemented with wireless technologies such as IEEE (institute of electrical and electronics engineers) 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802-20, E-UTRA (evolved UTRA), LTE (long term evolution), and 5G NR.

[0043] The technology described in this disclosure can be implemented as 6G wireless technology and applied to various 6G systems. For example, 6G systems may have key factors such as eMBB (enhanced mobile broadband), URLLC (ultra-reliable low latency communications), mMTC (massive machine-type communication), AI (artificial intelligence) integrated communication, tactile internet, high throughput, high network capacity, high energy efficiency, low backhaul and access network congestion, and enhanced data security.

[0044] Network structure

[0045] FIG. 1 illustrates an exemplary flexible network topology to which some examples of the present disclosure may be applied.

[0046] To compensate for incomplete areas of network coverage, a network topology in which the split radio access network (RAN) is configured more flexibly and resiliently may be considered. To this end, various nodes such as integrated access backhaul (IAB) nodes, relays, and radio frequency (RF) repeaters, as exemplified in Fig. 1, may be applied, and a non-terrestrial network (NTN) may be integrated. For example, an IAB node may correspond to a node that provides wireless backhaul. For example, a relay may refer to any intermediate point, and in the case of a sidelink relay where a terminal functions as a relay, it may collectively refer to a terminal-to-network (U2N) relay and a terminal-to-terminal (U2U) relay. For example, an RF repeater may correspond to a node that performs simple signal amplification and forwarding functions, and in the case of a network-controlled repeater, it may adjust transmit / receive settings based on information provided by the network as well as signal amplification and forwarding. For example, NTN nodes can correspond to satellites or aircraft that provide NTN coverage that is difficult for terrestrial networks to provide. In addition to these examples, various intermediate points can be introduced to improve the network topology.

[0047] Referring to FIG. 1, a split RAN can support the division of a base station into one centralized unit (CU) and one or more distributed units (DU). The CU and DU may correspond to logical units. The CU may be further divided into a control plane (CP) portion and one or more user plane (UP) portions. Since a failure in the CU-CP affects not only the CU-UP but also the DU, various intermediate points may be introduced to compensate for this.

[0048] An intermediate point may correspond to a terminal or a base station depending on its relative relationship with other nodes. For example, an IAB node may include a mobile-termination (MT) portion and a DU. The MT may connect the IAB node to a donor node. The DU of the IAB node may serve other terminals or connect to other IAB nodes to provide multi-hop wireless backhaul to terminals. For example, an IAB node may correspond to a base station in its relative relationship with a user-side node and to a terminal in its relative relationship with a network-side node.

[0049] In some examples of the present disclosure, the description of a terminal may apply equally to an intermediate point corresponding to a terminal in relation to a network-side endpoint as well as to a user-side endpoint. Similarly, in some examples of the present disclosure, the description of a base station may apply equally to an intermediate point corresponding to a base station in relation to a user-side endpoint as well as to a network-side endpoint. In most cases where there is no additional description of the operation of three or more subjects, the communication subjects in the present disclosure are briefly described by the term terminal and / or base station (or first node and / or second node), wherein the term terminal and / or base station (or first node and / or second node) is interpreted to include or replace any endpoint or any intermediate point in relation to other nodes.

[0050] As such, in some examples of the present disclosure, for the sake of brevity of description, the subject of the operation may be referred to as a terminal and / or base station (or a first node and / or a second node). Additionally, the term terminal and / or base station (or a first node and / or a second node) may be interpreted or substituted as in the following examples: for example, the terminal (or first node) and the base station (or second node) may correspond to a first endpoint and a second endpoint, respectively; may correspond to an endpoint and an intermediate point, respectively; may correspond to an intermediate point and an endpoint, respectively; or may correspond to a first intermediate point and a second intermediate point, respectively.

[0051] In the present disclosure, there may be no intermediate points between the base station and the terminal, or there may be one or more. If intermediate points exist, the intermediate points may correspond to IAB nodes, relays, RF repeaters, NTN nodes, or nodes supporting other functions. The intermediate points may be nodes with a fixed location or nodes with an indefinite location.

[0052] Systems applicable to the present disclosure

[0053] FIG. 2 illustrates an exemplary communication system to which some examples of the present disclosure may be applied.

[0054] The communication system (100) to which the present disclosure applies includes a wireless device (110), a network device (120), and a network (130). Here, the wireless device (110) refers to a device that performs communication using wireless access technology (e.g., LTE, LTE-A, LTE-A pro, NR, 5G, 5G-A, 6G) and may be referred to as a communication / wireless / 5G / 6G device. Although not limited thereto, the wireless device (110) may include a robot (110a), a vehicle (110b-1, 110b-2), an XR (extended reality) device (110c), a hand-held device (110d), a home appliance (110e), an IoT (Internet of Thing) device (110f), and an AI (artificial intelligence) device / server (110g). For example, the vehicle may include a vehicle equipped with wireless communication capabilities, an autonomous vehicle, a vehicle capable of performing inter-vehicle communication, etc. Here, the vehicle (110b-1, 110b-2) may include an unmanned aerial vehicle (UAV) (e.g., a drone). The XR device (110c) includes an augmented reality (AR) / virtual reality (VR) / mixed reality (MR) device and may be implemented in the form of a head-mounted device (HMD), a head-up display (HUD) equipped in a vehicle, a television, a smartphone, a computer, a wearable device, a home appliance, digital signage, a vehicle, a robot, etc. The portable device (110d) may include a smartphone, a smart pad, a wearable device (e.g., a smart watch, smart glasses), a computer (e.g., a laptop, etc.). The home appliance (110e) may include a TV, a refrigerator, a washing machine, etc. The IoT device (110f) may include a sensor, a smart meter, etc. The wireless device (110) may correspond to a terminal (or first node) or an intermediate point.The network device (120) may correspond to a base station (or a second node) or another intermediate point. For example, the network device (120) may also be implemented as a wireless device (110), and a specific wireless device (120a) may operate as a network device (120) to another wireless device (110).

[0055] Wireless devices (110a to 110f) can be connected to a network (130) through a network device (120). AI technology may be applied to the wireless devices (110a to 110f), and the wireless devices (110a to 110f) can be connected to an AI server (110g) through the network (130). The network (130) can be configured using a 3G network, a 4G (e.g., LTE) network, a 5G (e.g., NR) network, or a 6G network. The wireless devices (110a to 110f) may communicate with each other through the network device (120) / network (130), but may also communicate directly (e.g., sidelink communication) without going through the network device (120) / network (130). For example, vehicles (110b-1, 110b-2) can communicate directly (e.g., V2V (vehicle to vehicle) / V2X (vehicle to everything) communication). Also, an IoT device (110f) (e.g., a sensor) can communicate directly with another IoT device (e.g., a sensor) or other wireless devices (110a to 110f).

[0056] Wireless communication / connection (150a, 150b, 150c) can be established between wireless devices (110a to 110f) / network devices (120) and between network devices (120). Here, wireless communication / connection can be established through various wireless access technologies such as uplink / downlink communication (150a), sidelink communication (150b) (or D2D communication), and communication between network devices (150c) (e.g., relay, IAB (integrated access backhaul)). Through wireless communication / connection (150a, 150b, 150c), wireless devices and network devices / wireless devices, and network devices and network devices can transmit / receive wireless signals to / from each other. For example, wireless communication / connection (150a, 150b, 150c) can transmit / receive signals through various physical channels. To this end, based on the various descriptions of the present disclosure, at least some of the following may be performed: a process for setting various configuration information for transmitting / receiving wireless signals, a process for various signal processing (e.g., channel encoding / decoding, modulation / demodulation, resource mapping / demapping, etc.), a resource allocation process, etc.

[0057] Devices applicable to the present disclosure

[0058] FIG. 3 illustrates an exemplary wireless device to which some examples of the present disclosure may be applied.

[0059] Referring to FIG. 3, the wireless device (200) can transmit and receive wireless signals through various wireless access technologies (e.g., LTE, LTE-A, LTE-A pro, NR, 5G, 5G-A, 6G). The wireless device (200) includes at least one processor (202) and at least one memory (204), and may additionally include at least one transceiver (206) and / or at least one antenna (208).

[0060] The processor (202) controls the memory (204) and / or the transceiver (206) and may be configured to implement the descriptions, functions, procedures, proposals, methods, and / or sequences of operation disclosed in this document. For example, the processor (202) may process information within the memory (204) to generate a first information / signal and then transmit a wireless signal containing the first information / signal through the transceiver (206). Additionally, the processor (202) may receive a wireless signal containing a second information / signal through the transceiver (206) and then store information obtained from the signal processing of the second information / signal in the memory (204). The memory (204) may be connected to the processor (202) and may store various information related to the operation of the processor (202). For example, memory (204) may store software code containing instructions for performing some or all of the processes controlled by the processor (202) or for performing the descriptions, functions, procedures, proposals, methods, and / or sequences of operations disclosed in this document. Here, the processor (202) and memory (204) may be part of a communication modem / circuit / chip designed to implement wireless communication technology. A transceiver (206) may be connected to the processor (202) and may transmit and / or receive wireless signals through at least one antenna (208). The transceiver (206) may include a transmitter and / or receiver. The transceiver (206) may be interchangeable with a radio frequency (RF) unit. In this disclosure, a wireless device may mean a communication modem / circuit / chip.

[0061] Hereinafter, hardware elements of the wireless device (200) will be described in more detail. Although not limited thereto, at least one protocol layer may be implemented by at least one processor (202). For example, at least one processor (202) may implement at least one layer (e.g., functional layers such as PHY (physical), MAC (media access control), RLC (radio link control), PDCP (packet data convergence protocol), RRC (radio resource control), and SDAP (service data adaptation protocol). At least one processor (202) may generate at least one PDU (Protocol Data Unit) and / or at least one SDU (service data unit) according to the descriptions, functions, procedures, proposals, methods and / or operation sequences disclosed in this document. At least one processor (202) may generate messages, control information, data, or information according to the descriptions, functions, procedures, proposals, methods and / or operation sequences disclosed in this document. At least one processor (202) may generate a signal (e.g., a baseband signal) including a PDU, SDU, message, control information, data, or information according to the functions, procedures, proposals, and / or methods disclosed in this document and provide it to at least one transceiver (206). At least one processor (202) may receive a signal (e.g., a baseband signal) from at least one transceiver (206) and may obtain a PDU, SDU, message, control information, data, or information according to the descriptions, functions, procedures, proposals, methods, and / or operation sequences disclosed in this document.

[0062] At least one processor (202) may be referred to as a controller, microcontroller, microprocessor, or microcomputer. At least one processor (202) may be implemented by hardware, firmware, software, or a combination thereof. For example, at least one application-specific integrated circuit (ASIC), at least one digital signal processor (DSP), at least one digital signal processing device (DSPD), at least one programmable logic device (PLD), or at least one field programmable gate array (FPGA) may be included in at least one processor (202). The descriptions, functions, procedures, proposals, methods, and / or operation sequences disclosed in this document may be implemented using firmware or software, and the firmware or software may be implemented to include modules, procedures, functions, etc. Firmware or software configured to perform the descriptions, functions, procedures, proposals, methods, and / or operation sequences disclosed in this document may be included in at least one processor (202) or stored in at least one memory (204) and driven by at least one processor (202). The descriptions, functions, procedures, proposals, methods, and / or flowcharts disclosed in this document may be implemented using firmware or software in the form of code, instructions, and / or sets of instructions.

[0063] At least one memory (204) may be connected to at least one processor (202) and may store various forms of data, signals, messages, information, programs, codes, instructions, and / or commands. At least one memory (204) may be composed of ROM (read-only memory), RAM (random access memory), EPROM (erasable programmable read-only memory), flash memory, hard drive, registers, cache memory, computer read storage media, and / or combinations thereof. At least one memory (204) may be located inside and / or outside of at least one processor (202). Additionally, at least one memory (204) may be connected to at least one processor (202) via various technologies, such as wired or wireless connections.

[0064] At least one transceiver (206) may transmit user data, control information, wireless signals / channels, etc., as mentioned in the methods and / or operation flowcharts, etc. of this document to at least one other device. At least one transceiver (206) may receive user data, control information, wireless signals / channels, etc., as mentioned in the descriptions, functions, procedures, proposals, methods and / or operation flowcharts, etc. disclosed in this document from at least one other device. For example, at least one transceiver (206) may be connected to at least one processor (202) and may transmit and receive wireless signals. For example, at least one processor (202) may control at least one transceiver (206) to transmit user data, control information, or wireless signals to at least one other device. Additionally, at least one processor (202) may control at least one transceiver (206) to receive user data, control information, or wireless signals from at least one other device. Additionally, at least one transceiver (206) may be connected to at least one antenna (208), and at least one transceiver (206) may be configured to transmit and receive user data, control information, wireless signals / channels, etc., as described in the descriptions, functions, procedures, proposals, methods, and / or operation sequence diagrams disclosed in this document through at least one antenna (208). In this document, at least one antenna may be a plurality of physical antennas or a plurality of logical antennas (e.g., antenna ports). At least one transceiver (206) may convert the received wireless signals / channels, etc., from RF band signals to baseband signals in order to process the received user data, control information, wireless signals / channels, etc., using at least one processor (202).At least one transceiver (206) can convert user data, control information, wireless signals / channels, etc. processed using at least one processor (202) from a baseband signal to an RF band signal. To this end, at least one transceiver (206) may include an (analog) oscillator and / or filter.

[0065] The components of the wireless device described with reference to FIG. 3 may be referred to by other terms in terms of their function. For example, the processor (202) may be referred to as the control unit, the transceiver (206) as the communication unit, and the memory (204) as the storage unit. In some cases, the communication unit may be used to mean at least a part of the processor (202) and the transceiver (206).

[0066] The structure of the wireless device described with reference to FIG. 3 can be understood as the structure of at least part of various devices. For example, the structure of the wireless device illustrated in FIG. 3 may be at least part of the various devices described with reference to FIG. 2 (e.g., robot (110a), vehicle (110b-1, 110b-2), XR device (110c), portable device (110d), home appliance (110e), IoT device (110f), AI device / server (110g)). Furthermore, according to various embodiments, the device may include other components in addition to the components illustrated in FIG. 3.

[0067] For example, the device may be a portable device such as a smartphone, smartpad, wearable device (e.g., smart watch, smart glasses), or portable computer (e.g., laptop, etc.). In this case, the device may further include at least one of a power supply unit that supplies power and includes a wired / wireless charging circuit, a battery, etc., an interface unit that includes at least one port for connection with another device (e.g., an audio input / output port, a video input / output port), and an input / output unit for inputting and outputting video information / signals, audio information / signals, data, and / or information input by a user.

[0068] For example, the device may be a mobile device such as a mobile robot, vehicle, train, manned / unmanned aerial vehicle (AV), or ship. In this case, the device may further include at least one of a drive unit comprising at least one of an engine, motor, power train, wheel, brake, and steering device of the device; a power supply unit that supplies power and includes a wired / wireless charging circuit, battery, etc.; a sensor unit that senses state information, environmental information, and user information of the device or its surroundings; an autonomous driving unit that performs functions such as path maintenance, speed control, and destination setting; and a position measurement unit that acquires position information of the moving body through a GPS (global positioning system) and various sensors.

[0069] For example, the device may be an XR device such as an HMD, a HUD (head-up display) equipped in a vehicle, a television, a smartphone, a computer, a wearable device, a home appliance, digital signage, a vehicle, a robot, etc. In this case, the device may further include at least one of a power supply unit that supplies power and includes a wired / wireless charging circuit, a battery, etc., an input / output unit that acquires control information, data, etc. from the outside and outputs a generated XR object, and a sensor unit that senses state information, environment information, and user information of the device or the surroundings of the device.

[0070] For example, the device may be a robot that can be classified into industrial, medical, household, military, etc., depending on the purpose or field of use. In this case, the device may further include at least one of a sensor unit that senses state information, environmental information, and user information of the device or its surroundings, and a drive unit that performs various physical actions, such as moving robot joints.

[0071] For example, the device may be an AI device such as a TV, projector, smartphone, PC, laptop, digital broadcasting terminal, tablet PC, wearable device, set-top box (STB), radio, washing machine, refrigerator, digital signage, robot, vehicle, etc. In this case, the device may further include at least one of an input unit that acquires various types of data from the outside, an output unit that generates output related to sight, hearing, or touch, a sensor unit that senses state information, environmental information, and user information of the device or its surroundings, and a training unit that learns a model composed of an artificial neural network using training data.

[0072] The structure of the wireless device illustrated in FIG. 3 may be understood as part of a terminal (or first node), or part of an intermediate point, or part of a base station (or second node). If the device illustrated in FIG. 3 is a base station (or second node), the device may further include a wired transceiver for front haul and / or back haul communication. If the front haul and / or back haul communication is based on wireless communication, at least one transceiver (206) illustrated in FIG. 3 is used for front haul and / or back haul communication, and a wired transceiver may not be included.

[0073] Communication procedures

[0074] FIG. 4 illustrates an exemplary communication procedure between a first node and a second node to which some examples of the present disclosure may be applied.

[0075] FIG. 4 illustrates the operation of a first node (110) (e.g., a terminal) and a second node (120) (e.g., a base station) transmitting and / or receiving data, and the operation performed prior to this.

[0076] In step S101, the first node (110) and the second node (120) can perform synchronization. For example, the terminal (110) performs an initial cell search operation. Specifically, the terminal (110) can detect at least one synchronization signal transmitted from the base station (120) according to a predefined rule. Here, the synchronization signal may include a plurality of synchronization signals (e.g., a primary synchronization signal, a secondary synchronization signal) classified according to structure or use. Through this, the terminal (110) can identify the boundaries of the frame, subframe, slot, and / or symbol of the base station (120) and obtain information about the base station (120) (e.g., a cell identifier).

[0077] In step S103, the first node (110) can obtain system information transmitted from the second node (120). For example, the system information is information related to the attributes, characteristics, and / or capabilities of the base station (120) required to connect to the base station (120) and use the service, and can be classified according to content (e.g., whether it is essential for connection), transmission structure (e.g., the channel used, whether it is provided on-demand), etc., and can be classified, for example, into a master information block (MIB) and a system information block (SIB). If necessary, the terminal (110) may transmit a signal requesting system information prior to receiving the system information. Such request and provision of system information may be performed after a random access procedure described later.

[0078] In step S105, the first node (110) and the second node (120) can perform a random access procedure. For example, the terminal (110) can transmit and / or receive at least one message for the random access procedure (e.g., a random access preamble, a RAR (random access response) message, etc.) based on information related to the random access channel of the base station (120) obtained through system information (e.g., channel location, channel structure, structure of a supported preamble, etc.). For example, the terminal (110) may transmit a preamble (e.g., message 1 (MSG1)) through a random access channel, receive a random access response (RAR) message (e.g., message 2 (MSG2)), transmit a message (e.g., message 3 (MSG3)) containing information related to the terminal (110) (e.g., identification information) to the base station (120) using scheduling information included in the RAR message, and receive a message (e.g., message 4 (MSG4)) for contention resolution and / or connection establishment. As another example, MSG1 and MSG3 may be transmitted and received as a single message (e.g., message A (MSG A), or MSG2 and MSG4 may be transmitted and received as a single message (e.g., message B (MSG B).

[0079] In step S107, the first node (110) and the second node (120) can perform signaling of control information. For example, the control information may be defined in various layers, such as a layer that controls the connection (e.g., a radio resource control (RRC) layer), a layer that handles mapping between logical channels and transmission channels (e.g., a media access control (MAC) layer), and a layer that handles physical channels (e.g., a physical (PHY) layer). For example, the terminal (110) and the base station (120) may perform at least one of signaling to establish a connection, signaling to determine settings related to communication, and signaling to indicate allocated resources.

[0080] In step S109, the first node (110) and the second node (120) can transmit and / or receive data. For example, the terminal (110) and the base station (120) can process data based on the signaling of control information and transmit and / or receive data. For example, when transmitting data, the terminal (110) or the base station (120) can perform at least one of channel encoding, rate matching, scrambling, constellation mapping, layer mapping, waveform modulation, antenna mapping, and resource mapping on the information bits. For example, when receiving data, the terminal (110) or the base station (120) can perform at least one of extracting a signal from a resource, antenna-specific waveform demodulation, signal placement considering layer mapping, constellation demapping, descrambling, and channel decoding.

[0081] 6G System Core Technology

[0082] As core implementation technologies for 6G systems, technologies such as artificial intelligence (AI), THz (Terahertz) communication, optical wireless technology, free space optics (FSO) backhaul network, multiple input multiple output (MIMO) technology, blockchain, 3D networking, quantum communication, unmanned aerial vehicles, cell-free communication, wireless information and energy transfer (WIET), integration of sensing and communication, integration of access backhaul networks, holographic beamforming, big data analysis, and large intelligent surface (LIS) can be adopted.

[0083] artificial intelligence

[0084] The introduction of AI into communications can streamline and enhance real-time data transmission. AI can determine how complex target tasks are performed using numerous analyses. In other words, AI can increase efficiency and reduce processing latency. Time-consuming tasks such as handover, network selection, and resource scheduling can be performed instantly using AI. AI can also play a significant role in M2M, machine-to-human, and human-to-machine communication. Furthermore, AI can enable rapid communication in Brain-Computer Interfaces (BCI). AI-based communication systems can be supported by metamaterials, intelligent structures, intelligent networks, intelligent devices, intelligent cognitive radios, self-sustaining wireless networks, and machine learning.

[0085] The following describes a functional framework for AI / ML operations.

[0086] Below, to provide a more specific explanation of AI (or AI / ML), terms may be defined as follows.

[0087] - Data collection: Data collected from network nodes, management entities, or terminals, serving as a basis for AI model training, data analysis, and inference.

[0088] - AI Model: A data-driven algorithm that applies AI technology to generate a set of outputs containing predictive information and / or decision parameters based on a set of inputs.

[0089] - AI / ML Training: An online or offline process of training an AI model by learning features and patterns that best represent data and acquire an AI / ML model trained for inference.

[0090] - AI / ML Inference: A process of making predictions or deriving decisions based on collected data and AI models using trained AI models.

[0091] Life Cycle Management (LCM) procedures for AI / ML models (i.e., model training, model deployment, model inference, model monitoring, model updating, etc.) can be classified into functionality-based LCM and model-based LCM. In functionality-based LCM, AI / ML models may not be identifiable within the network, and the network can direct the activation, deactivation, fallback, or switching of AI / ML functionality. In model-ID (identifier)-based LCM, AI / ML models can be identified within the network, and the network or terminal can activate, deactivate, select, or switch AI / ML models via the model ID.

[0092] FIG. 5 illustrates an exemplary functional framework for AI / ML operations to which some examples of the present disclosure may be applied.

[0093] Figure 5 illustrates a general functional architecture related to both Functionality-based LCM and Model-based LCM. Some functions or some data / information / command flows (i.e., arrows) illustrated in Figure 5 may be omitted.

[0094] Referring to FIG. 5, a general functional framework may be configured to include a data collection function (10), a model training function (20), a management function (30), an inference function (40), and a model storage function (50).

[0095] The Data Collection function (10) is a function that provides input data to the Model Training function (20), Management function (30), and Inference function (40). The Data Collection function (10) performs data preparation based on raw data and can provide input data processed through data preparation. Examples of raw data may include received data / measurement data from terminals or other network entities, inference / output of AI / ML models, etc. The Data Collection function (10) may be performed by a single entity (e.g., terminal, network node, etc.) but may also be performed by multiple entities.

[0096] Here, training data (11) refers to data required as input for the AI / ML model training function (20). monitoring data (12) refers to data required as input for the management (30) of the AI / ML model or AI / ML function. inference data (13) refers to data required as input for the AI / ML inference function (30).

[0097] The Model Training function (20) is a function that performs AI / ML model training, validation, and testing, which can generate model performance metrics that can be used as part of the AI / ML model testing procedure. If necessary, the Model Training function (20) can perform data preparation (e.g., data pre-processing and cleaning, forming and transformation) based on the Training Data (11) delivered from the Data Collection function (10).

[0098] Trained / Updated Model (21): If there is a Model Storage function (50), it is used to transfer trained, validated, and tested AI / ML models to the Model Storage function (50) or to transfer updated versions of the models to the Model Storage function (50).

[0099] The Management function (30) is a function that supervises the operation of an AI / ML model or an AI / ML function. Additionally, the Management function (30) may make decisions to ensure appropriate inference operations based on data received from the Data Collection function (10) (i.e., Monitoring Data (12)) and / or data received from the Inference function (40) (i.e., Inference Output (41)).

[0100] Management Instruction (32) is information required as input to manage the Inference function (40). The relevant information may include the selection / (de)activation / switching of an AI / ML model or an AI / ML-based function, and may also include a fallback to a non-AI / ML operation (i.e., not relying on the inference process).

[0101] A Model Transfer / Delivery Request (33) can be used to request model(s) from Model Storage (50).

[0102] Performance Feedback / Retraining Request (31) refers to information required as input to Model Training function (20) (e.g., for the purpose of retraining or updating the model).

[0103] The inference function (40) is a function that provides output from the process of applying an AI / ML model or AI / ML function using data (i.e., inference data (13)) provided by the data collection (10) as input. Data preparation (e.g., data preprocessing and cleaning, formatting and transformation) may also be performed based on the inference data (13) delivered by the data collection (10). If necessary, the inference function (40) may also perform data preparation (e.g., data pre-processing and cleaning, forming and transformation) based on the inference data (13) provided by the data collection function (10).

[0104] Inference Output (41) is data used in the Management function (30) to monitor the performance of an AI / ML model or AI / ML function. Inference Output (41) may include the inference output of an AI / ML model generated by the Inference function (30), and the details of the inference output may vary depending on the use case.

[0105] The Model Storage function (50) is a function that stores a trained / updated model that can be used to perform the Inference function (40). The Model Storage function (50) exemplified in FIG. 2 can be used as a reference point (if any) applicable to protocol termination, model transmission / delivery, and related processes. Additionally, the Model Storage function (50) is an example and is not intended to restrict the storage location of the actual AI / ML model and may be omitted.

[0106] Model Transfer / Delivery (51) is used to transfer an AI / ML model to an inference function.

[0107] Cooperation levels can be defined as follows based on the capability of AI / ML functions among multiple nodes, and variations resulting from the combination of multiple levels or the separation of any one level are also possible.

[0108] Cat 0a) No collaboration framework: AI / ML algorithms are based on pure implementation and do not require changes to the wireless interface.

[0109] Cat 0b) This level corresponds to a framework that involves a wireless interface modified to fit efficient implementation-based AI / ML algorithms but without cooperation.

[0110] Cat 1) Inter-node support is involved to improve the AI / ML algorithms of each node. For example, this applies when a specific node receives support from other nodes (for training, adaptation, etc.) and vice versa. At this level, model exchange between network nodes is not required.

[0111] Cat 2) Collaborative AI / ML tasks can be performed among multiple nodes. This level requires the exchange of AI / ML model commands or network nodes.

[0112] FIG. 5 is a diagram illustrating an overall functional framework for an AI / ML model, and all functions and / or all data / information / command signals illustrated in FIG. 5 may not be performed within a specific node, and only some may be performed.

[0113] AI / ML models can be classified into one-side models and two-side models depending on whether training and / or inference are performed on a single node or jointly / sequentially on multiple nodes.

[0114] A one-side model can refer to an AI / ML model where inference is performed entirely by a single node (e.g., a terminal or a network). Here, the training of the AI / ML model can also be performed entirely by a single node. The training and inference of the AI / ML model may be performed by the same node, or they may be performed by different nodes.

[0115] A two-side model can refer to an AI / ML model in which joint inference is performed across multiple nodes (e.g., terminals and networks). Joint inference means that inference is performed collaboratively across multiple nodes; for example, the first part of the inference may be performed by the first node, and the remainder by the second node. Two-side models can be classified into various types as follows, depending on the training method of the AI / ML model.

[0116] - First type: An AI / ML model can be trained on a single node. In this case, joint training can be performed. The trained model can then be distributed to other nodes / entities.

[0117] - Second type: Joint training of AI / ML models can be performed on multiple nodes / entities (e.g., networks and terminals). Joint training can mean that model generation (e.g., CSI generation) and model reconstruction (CSI compression by sub-use cases) are trained in the same loop for forward activation and backward gradient. In this type, joint training can include both simultaneous training (i.e., model generation training and model reconstruction training are performed simultaneously) and sequential training (i.e., model reconstruction training is performed after model generation training).

[0118] - Third Type: Separate training of AI / ML models can be performed at multiple nodes (e.g., networks and terminals). Separate training may mean that training starts sequentially at one node and continues at another node. In this case, if the first node performs the AI / ML model first and shares the training data with the second node, the second node can perform the AI / ML model using the shared training data. For example, training for the CSI generation part may be performed by the terminal, while CSI reconstruction may be performed by the network.

[0119] FIG. 6 illustrates an exemplary communication procedure based on an AI / ML model between a first node and a second node to which some examples of the present disclosure may be applied.

[0120] Step 1: In the description of the present disclosure below, signaling (e.g., information / data / channel / signal, etc.) or a set of signaling between a specific node (e.g., terminal, network, etc.) and another node may be interpreted as the signaling or a set of signaling of Step 1 used to perform an operation based on an AI / ML model, unless otherwise noted. For example, it may correspond to training data for training (i.e., generation and / or reconstruction) the AI / ML model of FIG. 2, or to inference data used for inference of the AI / ML model, or to feedback to the AI / ML model, etc. If signaling between nodes is not required prior to an operation based on an AI / ML model in the present disclosure, Step 1 may be omitted. If a one-side model is used in the present disclosure, unidirectional / bidirectional signaling (set) in the present disclosure may correspond to the signaling of Step 1. In addition, when a two-side model is used in the present disclosure, unidirectional / bidirectional signaling in the present disclosure may correspond to one stage of signaling, and repetitive signaling operations may also correspond to one stage of signaling.

[0121] For example, in AI / ML model-based beam management, when a base station predicts (i.e., infers) high-quality beam(s) based on an AI / ML model, the base station can receive quality / intensity information for multiple beams from the terminal. Additionally, when a terminal predicts (i.e., infers) high-quality beam(s) based on an AI / ML model, the terminal can receive multiple beams from the base station.

[0122] Step 2: In the description of the present disclosure below, operations (e.g., computation, selection, prediction, etc.) at a specific node (e.g., terminal, network, etc.) or common operations (e.g., computation, selection, prediction, etc.) at multiple nodes (e.g., terminal, network, etc.) may correspond to operations of Step 2 based on one or more functions in the functional framework of an AI / ML model, unless otherwise noted. For example, they may correspond to the training (i.e., creation and / or reconstruction) of the AI / ML model of FIG. 2 or to inference of the AI / ML model. When a one-side model is used, operations performed by a single node in the present disclosure may correspond to operations of Step 2, and when a two-side model is used, common operations performed by multiple nodes in the present disclosure may correspond to operations of Step 2.

[0123] For example, in an AI / ML model-based BM, a base station can predict (i.e., infer) high-quality beam(s) based on an AI / ML model by using quality / intensity information for multiple beams received from a terminal as inference data. Additionally, a terminal can measure multiple beams received from a base station and predict (i.e., infer) high-quality beam(s) based on an AI / ML model by using the measurement results as inference data.

[0124] Step 3: In the description of the present disclosure below, signaling (e.g., information / data / channel / signal, etc.) or a set of signaling between a specific node (e.g., terminal, network, etc.) and another node may be interpreted as the signaling or set of signaling of Step 3 generated as a result of an operation based on an AI / ML model, even if not otherwise mentioned. For example, it may correspond to the output resulting from the inference of the AI / ML model of FIG. 2. If signaling between nodes is not required as a result of an operation based on an AI / ML model in the present disclosure, Step 3 may be omitted. If a one-side model is used in the present disclosure, unidirectional / bidirectional signaling (set) in the present disclosure may correspond to the signaling of Step 3. Furthermore, if a two-side model is used in the present disclosure, unidirectional / bidirectional signaling in the present disclosure may correspond to the signaling of Step 3, and repetitive signaling operations may also correspond to the signaling of Step 3.

[0125] For example, in an AI / ML model-based BM, the base station may transmit beam(s) predicted based on the AI / ML model as candidates to the terminal so that the terminal can determine the optimal beam. Additionally, the terminal may report the beam(s) predicted based on the AI / ML model to the base station to request the base station to transmit candidate beams as candidates for determining the optimal beam.

[0126] THz communication

[0127] Data transmission rates can be increased by expanding bandwidth. This can be achieved by using sub-THz communication with wide bandwidth and applying advanced large-scale MIMO technology. THz waves, also known as sub-millimeter radiation, generally refer to a frequency band between 0.1 THz and 10 THz with corresponding wavelengths ranging from 0.03 mm to 3 mm. The 100 GHz–300 GHz band range (sub-THz band) is considered the primary portion of the THz band for cellular communication. Adding the sub-THz band to the mmWave band increases 6G cellular communication capacity. Among the defined THz bands, the 300 GHz–3 THz band is located in the far-infrared (IR) frequency band. Although the 300 GHz–3 THz band is part of the broadband, it lies at the boundary of the broadband and immediately following the RF band. Therefore, this 300 GHz–3 THz band exhibits similarities to RF.

[0128] FIG. 7 shows an electromagnetic spectrum to which some examples of the present disclosure may be applied.

[0129] Key characteristics of THz communication include (i) widely available bandwidth to support very high data transmission rates, and (ii) high path loss occurring at high frequencies (highly directional antennas are indispensable). The narrow beam width generated by highly directional antennas reduces interference. The small wavelength of THz signals allows a much larger number of antenna elements to be integrated into devices and BSs operating in this band. This enables the use of advanced adaptive array technologies that can overcome range limitations.

[0130] When transmitting system information (e.g., MIB) of a cell in the THz frequency band, it can be inefficient because, in the case of high frequency bands, beam sweeping must be performed more frequently to cover the entire area of ​​the cell as the beam width becomes narrower. In particular, transmitting system information using this method is even more inefficient when there are not many users in the cell.

[0131] FIG. 8 illustrates an exemplary system information transmission / reception procedure to which some examples of the present disclosure may be applied.

[0132] The example of FIG. 8 is applicable not only to THz communication environments but also to 6G communication environments where THz communication is not applied. In addition, the procedure illustrated in FIG. 8 can be combined with various embodiments of the present disclosure described below. For example, embodiments described below can be performed based on system information obtained by the procedure illustrated in FIG. 8.

[0133] In step S810, the second node (120) (e.g., a base station) can transmit system information of cell #1 through cell #2. For example, the base station provides at least two cells, cell #1 uses a THz frequency band, and cell #2 uses a frequency band other than the THz frequency band. Here, the system information may include at least one of a system frame number (SFN) generated at a higher layer, a PDCCH configuration for SIB1, cell barring, cell re-selection, and subcarrier spacing, and may include at least one of a synchronization signal / PBCH (physical broadcast channel) block index generated at a physical layer. To this end, as an example, cell #1 and cell #2 may have a secondary cell and primary cell relationship.

[0134] In step S830, the first node (110) (e.g., a terminal) can acquire synchronization for cell #1. Synchronization can be acquired by detecting a synchronization signal. Generally, synchronization is acquired prior to receiving system information, but since the system information for cell #1 is received in cell #2, the acquisition of synchronization for cell #1 can be performed after receiving the system information. For example, the terminal can acquire synchronization based on the system information. Alternatively, the acquisition of synchronization may be performed prior to step S1010.

[0135] In step S850, the first node (110) may transmit a signal to connect to cell #1. For example, the signal may include a random access preamble. The structure of such a signal and the resource for transmitting the signal (e.g., a channel) can be identified through system information. Subsequently, in step S1070, the first node (110) and the second node (120) may perform a connection procedure to cell #1 and perform communication.

[0136] The procedure described with reference to FIG. 8 may be performed when the first node (110) first connects to cell #1 of the second node (120). Alternatively, a similar procedure may be performed when the first node (110) handovers to cell #1 of the second node (120). However, in the case of a handover, the system information of cell #1 may be received from a cell of a different base station other than cell #2 of the second node (120).

[0137] Communication in the THz band is expected to experience severe path loss, and to overcome this, terminals and base stations may be required to use very sharp beams. The use of sharp beams implies that terminals and base stations must perform beam control in addition to beamforming, meaning that a very large number of beams are utilized. Consequently, aligning the transmit and receive beams between the base station and the terminal takes a very long time. Furthermore, if the beam alignment between the base station and the terminal is disrupted due to the movement of the terminal, time is frequently required to realign the beams, which may lead to link instability.

[0138] FIG. 9 illustrates an exemplary beam management procedure to which some examples of the present disclosure may be applied.

[0139] Figure 9 illustrates an example of a procedure for searching and / or selecting beams for THz communication, but this procedure is not limited to a THz environment and can also be applied in a 6G communication environment where THz communication is not applied.

[0140] Here, the term "beam" can be interpreted as other terms having equivalent technical meanings capable of distinguishing beams, such as "spatial domain filter," "spatial domain transmit filter," "spatial domain receive filter," reference signal (RS) resources for distinguishing beams, and SSB index.

[0141] In step S910, the second node (120) (e.g., a base station) may set resources for beam management to the first node (110) (e.g., a terminal). Here, the resources may include at least one of time-frequency resources, channels, and spatial resources (e.g., antenna ports). For example, the base station may utilize a beam search signal (BSS) that is transmitted spatially separated from the existing downlink signal / channel for beam search. Here, the BSS may be transmitted based on a dedicated port for beam search. The dedicated port may be a port different from the port used for transmitting the existing downlink signal / channel (e.g., SSB, PDSCH (physical downlink shared channel), etc.). BSS is a term defined for convenience of explanation, and the technical concept according to the present embodiment is not limited to the term BSS itself. For example, a signal transmitted based on a dedicated port defined / set for beam search may be included in the technical concept according to the present embodiment.

[0142] In step S930, the second node (120) (e.g., a base station) transmits measurement signals using multiple transmission beams. For example, the measurement signals may include at least one of a reference signal and a synchronization signal. At this time, the measurement signals may be transmitted as many times as the number of beams requiring measurement, and may be transmitted using a multi-beam transmission method that forms multiple beams simultaneously to reduce sweeping time. Here, multi-beam transmission may be performed based on at least one of a multi-panel, a sub-array, or a true time delay (TTD).

[0143] In step S950, the first node (110) (e.g., a terminal) may transmit a feedback signal to the second node (120) (e.g., a base station). The feedback signal may indicate at least one beam selected by the terminal. The terminal may select at least one preferred beam based on the measurement signals received in step S1030.

[0144] In step S970, the first node (110) and the second node (120) can communicate. For example, the second node (120) can perform transmission to the first node (110) using the receiving beam of the first node (110) selected in step S1050. If channel reciprocity is established, the transmission beam of the first node (110) can also be determined through steps S1030 and S1050, so the transmission operation from the first node (110) can also be performed using a beam that has a reciprocity relationship with the beam selected in step S1050. If channel reciprocity is not established, a procedure including the transmission of measurement signal(s) by the first node (110) and the transmission of feedback signal(s) by the second node (120) may be performed first to determine the transmission beam of the first node (110).

[0145] Channel State Information (CSI) Related Operations

[0146] In NR (New Radio) systems, CSI-RS (channel state information-reference signal) is used for time and / or frequency tracking, CSI computation, L1 (layer 1)-RSRP (reference signal received power) computation, and mobility. Here, CSI computation is related to CSI acquisition, and L1-RSRP computation is related to beam management (BM).

[0147] CSI (channel state information) is a general term for information that can indicate the quality of the wireless channel (also called a link) formed between a terminal and an antenna port.

[0148] - To perform one of the uses of CSI-RS as described above, a terminal (e.g., user equipment, UE) receives configuration information related to CSI from a base station (e.g., general Node B, gNB) via RRC (radio resource control) signaling.

[0149] The configuration information related to the above CSI may include at least one of information related to CSI-IM (interference management) resources, information related to CSI measurement configurations, information related to CSI resource configurations, information related to CSI-RS resources, or information related to CSI report configurations.

[0150] i) Information related to CSI-IM resources may include CSI-IM resource information, CSI-IM resource set information, etc. A CSI-IM resource set is identified by a CSI-IM resource set ID (identifier), and one resource set includes at least one CSI-IM resource. Each CSI-IM resource is identified by a CSI-IM resource ID.

[0151] ii) Information related to CSI resource configuration may be expressed as CSI-ResourceConfig IE. Information related to CSI resource configuration defines a group including at least one of an NZP (non-zero power) CSI-RS resource set, a CSI-IM resource set, or a CSI-SSB resource set. That is, the information related to CSI resource configuration includes a CSI-RS resource set list, and the CSI-RS resource set list may include at least one of an NZP CSI-RS resource set list, a CSI-IM resource set list, or a CSI-SSB resource set list. A CSI-RS resource set is identified by a CSI-RS resource set ID, and one resource set includes at least one CSI-RS resource. Each CSI-RS resource is identified by a CSI-RS resource ID.

[0152] For each NZP CSI-RS resource set, parameters indicating the use of CSI-RS (e.g., BM-related 'repetition' parameter, tracking-related 'trs-Info' parameter) can be set.

[0153] iii) Information related to the CSI report configuration includes a reportConfigType parameter representing the time domain behavior and a reportQuantity parameter representing the quantity of CSI related to reporting. The time domain behavior may be periodic, aperiodic, or semi-persistent.

[0154] - The terminal measures the CSI based on configuration information related to the above CSI.

[0155] The above CSI measurement may include (1) a process of receiving CSI-RS from a terminal and (2) a process of computing CSI through the received CSI-RS, and a detailed explanation thereof will be provided later.

[0156] In CSI-RS, the mapping of resource elements (RE) of CSI-RS resources in the time and frequency domains is established by the higher layer parameter CSI-RS-ResourceMapping.

[0157] - The terminal reports the above-mentioned CSI to the base station.

[0158] Here, if the quantity of CSI-ReportConfig is set to 'none (or No report)', the terminal may omit the report. However, even if the quantity is set to 'none (or No report)', the terminal may still report to the base station. The case where the quantity is set to 'none' is when aperiodic TRS is triggered or when repetition is set. Here, the terminal may omit the report only when repetition is set to 'ON'.

[0159] 1) CSI measurement

[0160] The NR system supports more flexible and dynamic CSI measurement and reporting. Here, the CSI measurement may include a procedure for receiving CSI-RS and acquiring CSI by computationing the received CSI-RS.

[0161] As time domain behaviors for CSI measurement and reporting, aperiodic / semi-persistent / periodic CM (channel measurement) and IM (interference measurement) are supported. A 4-port NZP CSI-RS RE pattern is used for CSI-IM configuration.

[0162] NR's CSI-IM-based IMR has a design similar to LTE's CSI-IM and is configured independently of ZP CSI-RS resources for PDSCH rate matching. In addition, in the NZP CSI-RS-based IMR, each port emulates an interference layer with (desired channel and) precoded NZP CSI-RS. This is for intra-cell interference measurement in the multi-user case and primarily targets MU interference.

[0163] The base station transmits precoded NZP CSI-RS to the terminal on each port of the configured NZP CSI-RS-based IMR.

[0164] The terminal measures interference by assuming a channel / interference layer for each port in the resource set.

[0165] For a channel, if there is no PMI and RI feedback, multiple resources are set, and the base station or network indicates a subset of NZP CSI-RS resources via DCI for channel / interference measurement.

[0166] We will examine resource setting and resource setting configuration in more detail.

[0167] 2) Resource setting

[0168] Each CSI resource setting 'CSI-ResourceConfig' contains a configuration for S≥1 CSI resource sets (given by the higher layer parameter csi-RS-ResourceSetList). The CSI resource setting corresponds to the CSI-RS-resourcesetlist, where S represents the number of configured CSI-RS resource sets. Here, the configuration for S≥1 CSI resource sets includes each CSI resource set containing CSI-RS resources (configured as NZP CSI-RS or CSI-IM) and the SS / PBCH block (SSB) resource used for L1-RSRP computation.

[0169] Each CSI resource setting is located in a DL BWP (bandwidth part) identified by the higher layer parameter bwp-id. Additionally, all CSI resource settings linked to a CSI reporting setting have the same DL BWP.

[0170] Within the CSI resource setting included in CSI-ResourceConfig IE, the time domain behavior of the CSI-RS resource is dictated by the higher layer parameter resourceType and can be set to aperiodic, periodic, or semi-persistent. For periodic and semi-persistent CSI resource settings, the number of configured CSI-RS resource sets (S) is limited to '1'. For periodic and semi-persistent CSI resource settings, the configured periodicity and slot offset are given from the numerology of the associated DL BWP, as given by bwp-id.

[0171] When a UE is configured with multiple CSI-ResourceConfigs containing the same NZP CSI-RS resource ID, the same time domain behavior is configured for the CSI-ResourceConfigs.

[0172] When a UE is configured with multiple CSI-ResourceConfigs containing the same CSI-IM resource ID, the same time domain behavior is configured for the CSI-ResourceConfigs.

[0173] Next, one or more CSI resource settings for channel measurement (CM) and interference measurement (IM) are established through higher layer signaling.

[0174] - CSI-IM resource for interference measurement.

[0175] - NZP CSI-RS resources for interference measurement.

[0176] - NZP CSI-RS resources for channel measurement.

[0177] That is, the CMR (channel measurement resource) may be an NZP CSI-RS for CSI acquisition, and the IMR (Interference measurement resource) may be an NZP CSI-RS for CSI-IM and IM.

[0178] Here, CSI-IM (or ZP CSI-RS for IM) is primarily used for inter-cell interference measurements.

[0179] Also, the NZP CSI-RS for IM is mainly used for intra-cell interference measurement from multi-users.

[0180] The UE can assume that the CSI-RS resource(s) for channel measurement and the CSI-IM / NZP CSI-RS resource(s) for interference measurement set for one CSI reporting are 'QCL-TypeD' on a resource-by-resource basis.

[0181] 3) Resource setting configuration

[0182] As examined, resource setting can refer to a resource set list.

[0183] For aperiodic CSI, each trigger state set using the higher layer parameter CSI-AperiodicTriggerState is associated with one or more CSI-ReportConfigs, each of which is linked to a periodic, semi-persistent, or aperiodic resource setting.

[0184] One reporting setting can be linked to up to three resource settings.

[0185] - When a resource setting is set, the resource setting (given by the higher layer parameter resourcesForChannelMeasurement) is for channel measurements for L1-RSRP computation.

[0186] - When two resource settings are set, the first resource setting (given by the higher layer parameter resourcesForChannelMeasurement) is for channel measurement, and the second resource setting (given by csi-IM-ResourcesForInterference or nzp-CSI-RS-ResourcesForInterference) is for interference measurement performed on CSI-IM or NZP CSI-RS.

[0187] - When three resource settings are set, the first resource setting (given by resourcesForChannelMeasurement) is for channel measurement, the second resource setting (given by csi-IM-ResourcesForInterference) is for CSI-IM based interference measurement, and the third resource setting (given by nzp-CSI-RS-ResourcesForInterference) is for NZP CSI-RS based interference measurement.

[0188] For semi-persistent or periodic CSI, each CSI-ReportConfig is linked to a periodic or semi-persistent resource setting.

[0189] - When a resource setting (given by resourcesForChannelMeasurement) is configured, said resource setting is for channel measurements for L1-RSRP computation.

[0190] - When two resource settings are configured, the first resource setting (given by resourcesForChannelMeasurement) is for channel measurement, and the second resource setting (given by higher layer parameter csi-IM-ResourcesForInterference) is used for interference measurement performed on CSI-IM.

[0191] 4) CSI Computation

[0192] When interference measurements are performed on CSI-IM, each CSI-RS resource for channel measurement is associated with a CSI-IM resource by resource in the order of CSI-RS resources and CSI-IM resources within the corresponding resource set. The number of CSI-RS resources for channel measurement is equal to the number of CSI-IM resources.

[0193] And, when interference measurement is performed in NZP CSI-RS, the UE does not expect to be set to one or more NZP CSI-RS resources in the associated resource set within the resource setting for channel measurement.

[0194] A terminal with the Higher layer parameter nzp-CSI-RS-ResourcesForInterference configured does not expect more than 18 NZP CSI-RS ports to be configured within the NZP CSI-RS resource set.

[0195] For CSI measurement, the terminal assumes the following:

[0196] - Each NZP CSI-RS port configured for interference measurement corresponds to the interference transport layer.

[0197] - All interference transmission layers of the NZP CSI-RS port for interference measurement consider the EPRE (energy per resource element) ratio.

[0198] - Other interference signals on the RE(s) of the NZP CSI-RS resource for channel measurement, the NZP CSI-RS resource for interference measurement, or the CSI-IM resource for interference measurement.

[0199] 5) CSI Report

[0200] For CSI reporting, the time and frequency resources available to the UE are controlled by the base station.

[0201] Channel state information (CSI) may include at least one of a channel quality indicator (CQI), a precoding matrix indicator (PMI), a CSI-RS resource indicator (CRI), an SS / PBCH block resource indicator (SSBRI), a layer indicator (LI), a rank indicator (RI), or an L1-RSRP.

[0202] For CQI, PMI, CRI, SSBRI, LI, RI, and L1-RSRP, the terminal is configured by a higher layer with N≥1 CSI-ReportConfig reporting settings, M≥1 CSI-ResourceConfig resource settings, and a list of one or two trigger states (provided by aperiodicTriggerStateList and semiPersistentOnPUSCH-TriggerStateList). In the aperiodicTriggerStateList, each trigger state includes an associated list of CSI-ReportConfigs indicating resource set IDs for the channel and optionally interference. In the semiPersistentOnPUSCH-TriggerStateList, each trigger state includes one associated CSI-ReportConfig.

[0203] In addition, the time domain behavior of CSI reporting supports periodic, semi-persistent, and aperiodic.

[0204] i) Periodic CSI reporting is performed on short PUCCH and long PUCCH. The periodicity and slot offset of Periodic CSI reporting can be set to RRC, and refer to CSI-ReportConfig IE.

[0205] ii) SP (semi-periodic) CSI reporting is performed on short PUCCH, long PUCCH, or PUSCH.

[0206] In the case of SP CSI on Short / long PUCCH, periodicity and slot offset are set to RRC, and CSI reporting is activated / deactivated with separate MAC CE / DCI.

[0207] In the case of SP CSI on PUSCH, the periodicity of SP CSI reporting is set to RRC, but the slot offset is not set to RRC, and SP CSI reporting is activated / deactivated by DCI(format 0_1). For SP CSI reporting on PUSCH, a separate RNTI (SP-CSI C-RNTI) is used.

[0208] The initial CSI reporting timing follows the PUSCH time domain allocation value specified by DCI, and subsequent CSI reporting timing follows the period set by RRC.

[0209] DCI format 0_1 ​​includes a CSI request field and can activate / deactivate a specific configured SP-CSI trigger state. SP CSI reporting has the same or similar activation / deactivation mechanism as the data transmission mechanism on SPS PUSCH.

[0210] iii) aperiodic CSI reporting is performed on PUSCH and triggered by DCI. In this case, information related to the trigger of aperiodic CSI reporting can be transmitted / instructed / set via MAC-CE.

[0211] In the case of an AP CSI with AP CSI-RS, the AP CSI-RS timing is set by the RRC, and the timing for AP CSI reporting is dynamically controlled by the DCI.

[0212] NR does not apply the method of splitting CSIs across multiple reporting instances (e.g., transmitting in the order of RI, WB PMI / CQI, SB PMI / CQI) that was applied to PUCCH-based CSI reporting in LTE. Instead, NR restricts the setting of specific CSI reports in short / long PUCCHs, and CSI omission rules are defined. Regarding AP CSI reporting timing, the PUSCH symbol / slot location is dynamically determined by the DCI, and candidate slot offsets are set by the RRC. For CSI reporting, the slot offset (Y) is set per reporting setting. For UL-SCH, the slot offset K2 is set separately.

[0213] Two CSI latency classes (low latency class and high latency class) are defined in terms of CSI computation complexity. Low-latency CSI refers to WB CSIs that include up to 4-port Type-I codebooks or up to 4-port non-PMI feedback CSIs. High-latency CSI refers to any CSI other than low-latency CSIs. For a normal terminal, (Z, Z') is defined in the unit of OFDM symbols. Here, Z represents the minimum CSI processing time from receiving an Aperiodic CSI-triggering DCI to performing a CSI report. Additionally, Z' represents the minimum CSI processing time from receiving a CSI-RS for channel / interference to performing a CSI report.

[0214] Additionally, the terminal reports the number of CSIs that can be calculated simultaneously.

[0215] The activation or deactivation of a semi-persistent CSI-RS / CSI-IM resource set is directed by the network via a specific MAC CE. The configured semi-persistent CSI-RS / CSI-IM resource set is initially deactivated at the time of configuration and after a handover. The MAC entity receiving the corresponding MAC CE directs the lower layer (e.g., PHY) to the information related to that MAC CE.

[0216] Aperiodic CSI trigger state subselection is directed from the network via a specific MAC CE, and an Aperiodic CSI trigger state can be selected from among the configured AP CSI trigger states of the serving cell. The MAC entity receiving the corresponding MAC CE instructs the lower layer (e.g., PHY) with information related to the MAC CE.

[0217] Sounding reference signal (SRS)

[0218] In Rel-15 NR, spatialRelationInfo can be used to indicate which transmission beam to use when a base station transmits a UL channel to a terminal. By configuring the RRC, the base station can indicate which UL transmission beam to use when transmitting PUCCH and SRS by setting a DL reference signal (e.g., SSB-RI (SB Resource Indicator), CRI (CSI-RS Resource Indicator) (P / SP / AP: periodic / semi-persistent / aperiodic)) or SRS (i.e., SRS resource) as a reference RS for the target UL channel and / or target RS. Additionally, when the base station schedules PUSCH to the terminal, the transmission beam indicated by the base station and used for SRS transmission is indicated as the transmission beam for PUSCH via the SRI field and is used as the terminal's PUSCH transmission beam.

[0219] The SRS for codebooks (CB) and non-codebooks (NCB) is described below.

[0220] First, in the case of a CB UL, the base station may first configure and / or instruct the terminal to transmit an SRS resource set for 'CB' purposes. Then, the terminal may transmit any n-port SRS resource within that SRS resource set. The base station receives the UL channel based on the SRS transmission and can utilize it for the terminal's PUSCH scheduling. Subsequently, when the base station performs PUSCH scheduling via the UL DCI, it may indicate the terminal's PUSCH beam by indicating the 'CB' purpose SRS resource previously transmitted by the terminal through the SRI field of the DCI. Additionally, the base station may indicate the UL rank and UL precoder by indicating the uplink codebook through the TPMI (transmitted precoder matrix indicator) field. Through this, the terminal can perform PUSCH transmission according to the instructions.

[0221] Next, even in the case of NCB UL, the base station may first set and / or instruct the terminal to transmit an SRS resource set for 'non-CB' purposes. Then, based on the reception of the NZP CSI-RS associated with the said SRS resource set, the terminal may determine the precoders for the SRS resources within the said SRS resource set (up to 4 resources, 1 port per resource) and transmit the said SRS resources simultaneously. Subsequently, when the base station performs PUSCH scheduling via the UL DCI, it may indicate the terminal's PUSCH (transmission) beam by indicating some of the 'non-CB' purpose SRS resources previously transmitted by the terminal through the SRI field of the DCI, and simultaneously indicate the UL rank and UL precoder. Through this, the terminal can perform PUSCH transmission according to the instructions.

[0222] The SRS for beam management is described below.

[0223] SRS can be utilized for beam management. Specifically, UL BM can be performed through beamformed UL SRS transmission. Whether UL BM is applied to an SRS resource set is determined by the (upper layer parameter) 'usage'. If usage is set to 'BeamManagement (BM)', only one SRS resource can be transmitted to each of multiple SRS resource sets within a given time instant. The terminal may receive one or more Sounding Reference Symbol (SRS) resource sets configured by the (upper layer parameter) 'SRS-ResourceSet' (via upper layer signaling, e.g., RRC signaling). For each SRS resource set, the UE may be configured with K≥1 SRS resources (upper layer parameter 'SRS-resource'). Here, K is a natural number, and the maximum value of K is indicated by SRS_capability.

[0224] The following describes the SRS for antenna switching.

[0225] SRS can be used to acquire Channel State Information (DL CSI) information (e.g., DL CSI acquisition). As a specific example, in a single-cell or multi-cell (e.g., carrier aggregation (CA)) situation based on TDD, a Base Station (BS) can measure the SRS from a User Equipment (UE) after scheduling the transmission of the SRS. In this case, the base station can schedule DL signals / channels for the UE based on the measurement by the SRS, assuming DL / UL reciprocity. At this time, regarding DL CSI acquisition based on the SRS, the SRS can be configured for antenna switching purposes.

[0226] For example, according to the standard (e.g., 3gpp TS38.214), the use of the SRS can be configured for the base station and / or terminal using a higher layer parameter (e.g., the usage of the RRC parameter SRS-ResourceSet). Here, the use of the SRS can be configured for beam management, codebook transmission, non-codebook transmission, antenna switching, etc.

[0227] Below, we will specifically examine the case where SRS transmission (i.e., transmission of an SRS resource or a set of SRS resources) is configured for antenna switching among the above uses.

[0228] For example, in the case of a terminal with partial reciprocity, SRS transmission based on antenna switching (i.e., transmission antenna switching) may be supported for the acquisition of downlink (DL) Channel State Information (CSI) via SRS transmission in situations such as Time Division Duplex (TDD). When antenna switching is applied, approximately 15 μs may generally be required between SRS resources (and / or between SRS resources and PUSCH / PUCCH resources) for the terminal's antenna switching. Considering this, a (minimum) guard period as shown in Table 1 below may be defined.

[0229] μΔf=2 μ ·15 [kHz]Y [Symbol]01511301260131202

[0230] In Table 1, μ represents numerology, Δf represents subcarrier spacing, and Y represents the number of symbols in the guard interval, i.e., the length of the guard interval. Referring to Table 1, the guard interval can be set based on the parameter μ, which determines the numerology. During the guard interval, the terminal is configured not to transmit any other signals, and the guard interval can be configured to be used entirely for antenna switching. For example, the guard interval can be configured considering SRS resources transmitted in the same slot. In particular, if the terminal is configured and / or instructed to transmit an aperioditic SRS configured for intra-slot antenna switching, the terminal transmits the SRS using a different transmission antenna for each designated SRS resource, and the guard interval described above can be set between each resource.

[0231] Additionally, as described above, if a terminal receives an SRS resource and / or an SRS resource set configured for antenna switching through upper-layer signaling, the terminal may be configured to perform SRS transmission based on its terminal capability related to antenna switching. Here, the terminal capability related to antenna switching may be '1T2R', '2T4R', '1T4R', '1T4R / 2T4R', '1T1R', '2T2R', '4T4R', etc. Here, 'mTnR' may refer to a terminal capability that supports m transmissions and n receptions.

[0232] (Example S1) For example, for a terminal supporting 1T2R, up to two sets of SRS resources may be set to different values ​​for the resourceType of the upper layer parameter SRS-ResourceSet. Here, each set of SRS resources may have two SRS resources transmitted in different symbols, and each SRS resource in a given set of SRS resources may constitute a single SRS port. Additionally, the SRS port for the second SRS resource in the set of SRS resources may be configured to be associated with a different UE antenna port than the SRS port for the first SRS resource in the same set of SRS resources.

[0233] (Example S2) As another example, for a terminal supporting 2T4R, up to two sets of SRS resources may be set to different values ​​for the resourceType of the upper layer parameter SRS-ResourceSet. Here, each set of SRS resources may have two SRS resources transmitted in different symbols, and each SRS resource in a given set of SRS resources may consist of two SRS ports. Additionally, the pair of SRS ports for the second SRS resource in the set of SRS resources may be configured to be associated with a different UE antenna port than the pair of SRS ports for the first SRS resource in the same set of SRS resources.

[0234] (Example S3) As another example, for a terminal supporting 1T4R, SRS resource sets may be configured in different ways depending on whether SRS transmission is configured to be periodic, semi-persistent, and / or aperioditic. First, when SRS transmission is configured to be periodic or semi-persistent, zero SRS resource sets configured based on the resourceType of the upper layer parameter SRS-ResourceSet, or one SRS resource set consisting of four SRS resources, may be configured to be transmitted on different symbols. Here, each SRS resource in a given SRS resource set may constitute a single SRS port. And, the SRS port for each SRS resource may be configured to be associated with a different UE antenna port. In contrast, when SRS transmission is configured non-periodically, zero sets of SRS resources configured based on the resourceType of the upper layer parameter SRS-ResourceSet, or two sets of SRS resources consisting of a total of four SRS resources, may be configured to be transmitted in different symbols of two different slots. Here, the SRS port for each SRS resource in the given two sets of SRS resources may be configured to be associated with different UE antenna ports.

[0235] (Example S4) As another example, for a terminal supporting 1T1R, 2T2R, or 4T4R, up to two sets of SRS resources, each consisting of one SRS resource, may be configured for SRS transmission. The number of SRS ports for each SRS resource may be configured to be 1, 2, or 4.

[0236] If the indicated terminal capability is 1T4R / 2T4R, the terminal may expect that the same number of SRS ports (e.g., 1 or 2) will be configured for all SRS resources in the SRS resource set(s). Additionally, if the indicated terminal capability is 1T2R, 2T4R, 1T4R, or 1T4R / 2T4R, the terminal may not expect that one or more sets of SRS resources configured for antenna switching in the same slot will be configured or triggered. Additionally, even if the indicated terminal capability is 1T1R, 2T2R, or 4T4R, the terminal may not expect that one or more sets of SRS resources configured for antenna switching in the same slot will be configured or triggered.

[0237] SRS port group-based operation using multiple CSI-RS resources

[0238] The present disclosure proposes a method for improving PDSCH reception performance when implementing a port group-based terminal, such as a multi-panel UE.

[0239] In 3GPP NR Rel-19, proposals for low-complexity terminal support are being discussed to enable terminals to achieve rank > 4 in multi-base station antenna port environments (e.g., 64Tx, 128Tx).

[0240] FIG. 10 illustrates a low-complexity receiver in a wireless communication system to which the present disclosure may be applied.

[0241] Referring to Fig. 10, the low-complexity terminal in the above discussion is assumed to be a terminal in which the MIMO receiver consists of two sub-receivers or panels, and in the TDD system, the terminal transmits an SRS port group for each panel. That is, the terminal transmits an SRS port group for each sub-receiver.

[0242] The base station can estimate each downlink sub-channel from the channels received from each SRS port group. For example, in the case of a 128Tx base station and an 8Rx terminal (with two 4Rx panels), it can estimate two 128x4 channels respectively. Based on this SRS port group-based channel estimation, the base station can perform precoding / beamforming by targeting different codewords (CW) toward each panel during PDSCH transmission.

[0243] However, for the above operation, the terminal's CSI reporting is required to determine the number of layers and the modulation and coding scheme (MCS) for each CW. To this end, when calculating / reporting CSI (e.g., CQI / RI), the terminal is under discussion for an operation to calculate and report CSI by assuming that it receives different CWs (codewords) from each panel through the base station (e.g., PMI / RI, first CQI for the first panel (i.e., first antenna port group) / codeword, second CQI for the second panel (i.e., first antenna port group) / codeword).

[0244] In this document, ' / ' signifies 'and', 'or', or 'and / or' depending on the context. In the present invention, 'beam' may refer to a (source / reference) reference signal (RS) for a 'spatial transmission / reception filter' or a 'spatial relation', and may be interpreted as a QCL (source / reference) RS, a (DL / UL / joint) TCI (transmission configuration indication) state, or (in the case of an uplink) a spatial relation RS (corresponding ID).

[0245] Additionally, in the description of the present disclosure, where one transmission block (TB) is individually mapped to one codeword (CW), the codeword in the present disclosure may be interpreted as equivalent to the transmission block.

[0246] The overall system operation of the technology for the low-complexity receiver described above can be summarized as shown in Figure 11 below.

[0247] FIG. 11 illustrates signaling between a base station and a UE having a low-complexity receiver in a wireless communication system to which the present disclosure may be applied.

[0248] In FIG. 11, for convenience of explanation, steps S1101 / S1102 are exemplified as being performed before steps S1103 / S1104, but steps S1101 / S1102 may also be performed after steps S1103 / S1104.

[0249] The base station transmits configuration information related to SRS transmission to the UE (S1102). Here, the configuration information may include various parameters / information related to SRS transmission, and in particular, the configuration information may include information for configuring multiple SRS port groups, and the configuration information may also include information for triggering SRS transmission.

[0250] The UE transmits SRS transmissions to the base station for each SRS port group from each receiving panel (or receiving unit) (S1102).

[0251] The base station transmits CSI-RS to the UE (S1103).

[0252] The UE reports / transmits the CSI derived from the received CSI-RS to the base station (S1104).

[0253] Here, CSI can be calculated / reported assuming that each SRS port group is mapped to each (i.e., different) CW. For example, in the case of TDD, CSI may include a first CQI for a first CW and a second CQI for a second CW with one RI.

[0254] The base station transmits PDSCH to the terminal (S1105).

[0255] Here, the base station can determine / apply a DL MIMO precoder by estimating a DL subchannel from the RI and CW-specific CQI information received from the UE in step S1104 and the UL subchannel estimation information obtained through the reception of the UE's SRS port group in step S1102.

[0256] Based on these methods, the following proposals were discussed at 3GPP.

[0257] Proposal 1.A.2: For antenna switching for each xT6R or xT8R, the entire P across one or more SRS resources SRS For UEs configured with 6 or 8 ports, the following fixed SRS port grouping is supported (sorted in ascending order according to the SRS resource ID (identifier) ​​and port number within each SRS resource P SRS Ports indexing).

[0258] - SRS Port Group 0, corresponding to CW0, is P SRS The first P among the ports SRS Includes / 2 ports.

[0259] - SRS Port Group 1, corresponding to CW1, is P SRS The second P among the ports SRS Includes / 2 ports.

[0260] Improvements to other regulations, such as the new CW-layer mapping, DL resource allocation, and DCI format, are not introduced.

[0261] Note: The grouping assumption above is intended to align the relationship between NW and UE regarding the correlation between the CQI and SRS ports reported for two CWs when reportQuantity = 'cri-RI-CQI'.

[0262] Note: Different SRS ports are associated with different UE antenna ports.

[0263] Note: If one CW is scheduled, both SRS port groups can correspond to the same CW.

[0264] Note: This feature is a separate UE feature, and for UEs that support it, it is configured via RRC.

[0265] Issue: In the implementation of the above method, when the UE calculates / reports the CSI in step S1104 of FIG. 11, panel-specific interference can be reduced by selecting / reporting a panel-specific PMI that minimizes interference for each receiving panel. However, the interference control method has a limitation in that it cannot be applied in the case of TDD CSI where PMI reporting is not performed (e.g., only (CRI) / CQI / RI / (LI) are reported). If panel-specific interference is significant, the above low-complexity receiver structure has the disadvantage of losing the original motivation of 'implementing a low-complexity receiver' because performance deteriorates due to inter-panel interference or implementation complexity increases due to the application of inter-panel interference removal / reduction techniques. In addition, there is a limitation in that even if the base station applies precoding to reduce inter-panel interference through the channel estimated in step S1102 in the PDSCH transmission step, i.e., step S1105 of FIG. 11, and transmits the PDSCH, the interference control effect is not reflected in the terminal's CSI calculation and reporting step, i.e., step S1104. That is, there can be a significant mismatch between the CSI calculated / reported by the terminal in S1104 and the values ​​related to CSI, such as the optimal rank value of the PDSCH transmitted with actual precoding applied and the MCS value (per CW).

[0266] To resolve the above issue, the present disclosure proposes the following method.

[0267] In the following description of the present disclosure, SRS port groups are primarily described for convenience of explanation, but the present disclosure is not limited thereto. In the description of the present disclosure, SRS port groups may be replaced with SRS resource(s). In other words, they may be divided into a first group comprising one or more SRS resources and a second group comprising one or more other SRS resources. Additionally, SRS port groups may be replaced with SRS resource sets. In other words, they may be divided into a first set of SRS resources and a second set of SRS resources.

[0268] Furthermore, in the description of the present disclosure, CSI-RS resources are primarily described for convenience of explanation, but the present disclosure is not limited thereto. In the description of the present disclosure, CSI-RS resources may be replaced with CSI-RS port groups. Additionally, each CSI-RS / SRS port group or each CSI-RS / SRS resource may correspond to / be associated with a panel (e.g., CSI-RS / SRS transmission panel), beam, etc., of a different UE.

[0269] Example 1: CSI-RS resource / CSI-RS port(s) for each SRS port group / CSI (e.g., CQI) can be configured / directed individually / separately.

[0270] Referring again to FIG. 11, the present embodiment is described as follows: the base station estimates the DL channel through the UL channel estimated from step S1102, and in step S1103, a beamformer / precoder can transmit beamformed / precoded CSI-RS that minimizes interference (e.g., inter-panel interference) for the DL channel corresponding to each SRS port group. For example, CSI-RS resource(s) #1 associated / mapped with SRS port group #1 may be beamformed / precoded CSI-RS port(s) designed to have excellent reception performance to panel #1 (or receiver #1) corresponding to SRS port group #1 and / or excellent reception performance to panel #2 (or receiver #2) corresponding to SRS port group #2. Likewise, CSI-RS resource(s) #2 associated with / mapped to SRS port group #2 may be beamformed / precoded CSI-RS port(s) designed to provide excellent reception performance to panel #2 (or receiver #2) corresponding to SRS port group #2 and / or excellent reception performance to panel #1 (or receiver #1) corresponding to SRS port group #1, or degraded reception performance to panel #1 (or receiver #1). In Example 1, the SRS port group may be an SRS resource(s) or a set of SRS resources. Additionally, the CSI-RS resource(s) associated with / mapped to each SRS port group may correspond to different CSI-RS resource(s), or the CSI-RS resource(s) associated with / mapped to each SRS port group may correspond to different CSI-RS antenna port(s) or CSI antenna port groups / sets of common CSI-RS resource(s).

[0271] To be more specific, the CSI-RS transmission method can be divided into (i) a case where resource-wise beamforming / precoding is applied to CSI-RS resource(s) (or port groups) and (ii) a case where port-wise beamforming is applied to CSI-RS ports. Case (i) corresponds to a case where a single / common beamformer / precoder is applied to the CSI-RS ports within the CSI-RS resource(s). Additionally, case (ii) corresponds to a case where independent beamforming is applied to each CSI-RS port. Here, for example, the existing NR codebook supports a port-selection codebook for case (ii) (e.g., there is only one non-zero element per vector), and also supports a vector / matrix selection type codebook for case (i).

[0272] In the case of (i) above, the base station may transmit CSI-RS with a precoder / beamformer applied to the SRS port group on a resource(s) basis. In this case, the UE may calculate / report CQI / RI for each receiving panel / port(s) corresponding to each SRS port group (assuming a reference precoder for TDD CSI calculation). Alternatively, PMI for each panel / port(s) may also be reported.

[0273] In the case of (ii) above, the base station may transmit CSI-RS with a precoder / beamformer applied to the SRS port group on a per-transmit port or per-port group basis. In this case, the UE may calculate / report the port select PMI and CQI / RI for each receiving panel / port(s) corresponding to each SRS port group. Alternatively, the UE may calculate / report the CQI / RI without sending the PMI (assuming a reference precoder for TDD CSI calculation).

[0274] In the above examples, RI may be calculated / reported as a single value for the entire receiving panel / port(s). If RI is selected for each CSI-RS resource(s) or port group, the total RI may be the sum of the RIs for each resource(s) (e.g., RI = RI#1 for CSI-RS resource(s) 1 + RI#2 for CSI-RS resource(s) 2), and the terminal may report information about the combination of these RIs to the base station. Alternatively, if mapping to a CW is performed for each SRS port group, and if the CW-layer mapping method supports only one mapping method per RI, such as in an NR / LTE system, the terminal may need to find and report a CSI that satisfies a combination of the number of supported layers (e.g., when RI=3, 1 layer in the 1st CW + 2 layers in the 2nd CW, etc.).

[0275] In the case of (ii) above, a target (or associated) SRS port group at the CSI-RS port or port group level may be configured / assigned to the UE. The base station may determine the beam(s) to be used per receiving panel or port(s) based on which CSI-RS port(s) the UE has selected / reported (as a port-select PMI).

[0276] When the proposed method of Example 1 is applied, the operation is described as follows with reference to FIG. 11.

[0277] The base station transmits configuration information related to SRS transmission to the UE (S1102). Here, the configuration information may include various parameters / information related to SRS transmission, and in particular, the configuration information may include information for configuring multiple SRS port groups, and additionally, the configuration information may include information for configuring CSI-RS resource(s) associated / mapped with each SRS port group. Additionally, the configuration information may include information for triggering SRS transmission.

[0278] The UE transmits SRS transmissions to the base station for each SRS port group from each receiving panel (or receiving unit) (S1102).

[0279] The base station transmits CSI-RS to the UE on the CSI-RS resources associated (mapped) to each SRS port group (S1103).

[0280] Here, after estimating the UL channel and the corresponding DL channel in step S1102, the base station can determine a precoder / beamformer for each SRS port group (e.g., terminal panel, sub-channel) and apply it to each CSI-RS resource(s) for transmission (e.g., beamformed / precoded CSI-RS transmission).

[0281] The UE reports / transmits the CSI derived from the received CSI-RS to the base station (S1104).

[0282] Here, the UE can calculate / derive / report CSIs assuming that each SRS port group / CSI-RS resource(s) is mapped to each CW (e.g., in the case of TDD, the CSI may include an RI, a first CQI (for the first CW / CSI-RS resource(s)), and a second CQI (for the second CW / CSI-RS resource).

[0283] The base station transmits PDSCH to the terminal (S1105).

[0284] Here, the base station can determine / apply a DL MIMO precoder (for PDSCH) by estimating a DL subchannel from the RI and CW-specific CQI information received from the UE in step S1104 and the UL subchannel estimation information received from the UE in step S1102 through the SRS port group reception.

[0285] The above-described embodiment 1 assumed a method of transmitting beamformed / precoded CSI-RS in step S1103 based on the channel for each terminal panel (or receiver) estimated in step S1102. Such beamformed / precoded CSI-RS, as a UE-dedicated CSI-RS, can cause DL resource overhead problems when a single base station supports / covers a large number of UEs.

[0286] Accordingly, a method is proposed to transmit beamformed / precoded CSI-RS in step S1103 based on a method different from Example 1, which can be configured to be UE group-specific or cell-specific. That is, when a base station transmits CSI-RS resources or ports (groups) to which any precoder / beamformer has been applied to a UE, the UE can select one or more preferred CSI-RS resources / ports (groups) from among these CSI-RS resources / ports (groups) and report them to the base station (e.g., CRI reporting or port-selection PMI reporting). In performing this operation, in the case of a low-complexity receiver UE or a multi-panel structure UE considered in this disclosure, information regarding which panel (or SRS port group) receives the selected CSI-RS resource / port (group)(s) can be transmitted to the base station.

[0287] Example 2: In a procedure in which a base station sets / transmits multiple CSI-RS resources or CSI-RS ports (groups) to a UE and the UE reports CSI to the base station, the UE may report an associated SRS port group ID (e.g., SRS resource set ID, CW ID associated with the SRS port group) along with a CSI-RS resource(s) or port (group) ID (e.g., CRI). Alternatively, it may be stipulated / configured to report CRIs sequentially according to the SRS port group or CW (e.g., the first CRI for SRS port group #1 / CW #1, the second CRI for SRS port group #2 / CW #2).

[0288] In Example 2, since each panel (or receiver) may only receive a single CW, CQI may be reported only once per CSI-RS resource(s), CSI-RS port (group), or SRS port group. For example, the following CSI information may be reported.

[0289] - CRI #1, (SRS Port Group ID #1), 1st CQI (for 1st CW / CRI / SRS resource set)

[0290] - CRI #2, (SRS Port Group ID #2), 2nd CQI (for 2nd CW / CRI / SRS resource set)

[0291] - RI

[0292] In the above example, CRI#1 and CRI#2 represent CSI-RS resources selected by the UE for SRS port group IDs#1 and ID#2, respectively. Here, SRS port group ID#1 and SRS port group ID#2 may be the same or different IDs (for example, if they are the same ID, this corresponds to an example where the UE transmits two CRIs for the same receiving panel). When configured to report layer indicators (LI) for mapping between PTRS (phase tracking reference signal) and DMRS ports, etc., in the terminal structure considered in this disclosure, since RF (radio frequency) characteristics differ for each transmitting / receiving panel / unit, it may be more desirable to report LIs for each panel / SRS port group / CW. Additionally, when configuring CSI reporting information, N CSI-RS resource(s) / port(group)(s) (where N is an integer greater than 0) may be reported for each UE panel or SRS port group. Here, the value of N may be set by the base station or a value specified in the standard. Alternatively, the terminal may determine the value of N and report a desired number of CSI-RS resource(s) / port(group)(s) to the base station. In this way, when the terminal reports the value of N, since the CSI payload size can vary depending on the value of N, a multi-part encoding method, such as two-part encoding, may be used for CSI encoding. Here, Part-1 CSI may report the value of N and / or a value related to whether the value of N is reported, and / or a value related to the total number of SRS port groups / CRI / CQI / CW (e.g., the existence of a second SRS port group / CRI / CQI / CW). Additionally, information related to the SRS port groups / CRI / CQI / CW may be reported as Part-2 CSI.Alternatively, a fixed number (e.g., 1) of SRS port group / CRI / CQI / CW related information may be included in Part-1 CSI, and the remaining SRS port group / CRI / CQI / CW related information may be reported in Part-2 CSI. For example, according to current NR standards, the existence of a second CQI is determined by whether the RI value is 4 or less or exceeds 4. On the other hand, if the two separate receiving structures of the UE considered in this disclosure are to be applied regardless of the RI value, the reporting of a second CQI may also be configured / regulated to be determined by the number of associated SRS port groups.

[0293] When a UE reports multiple CSI-RS resource(s) / port (group)(s), it can be defined / configured to report CRIs sequentially in the order of SRS port groups. In this way, if there is an agreement between the base station and the UE regarding which SRS port group / CW corresponds to which CSI-RS resource / port reported in which order, the SRS port group ID (e.g., SRS resource set ID) information may be omitted from the CSI report information. For example, the first reported CRI may be defined / configured as information regarding the CSI-RS(s) resource corresponding to the first SRS port group or first CW, and the second reported CRI may be defined as information regarding the CSI-RS(s) resource corresponding to the second SRS port group or second CW; or the base station may configure / instruct the terminal to do so, in which case the SRS port group ID may be omitted from the CSI report information. When multiple CRI(s) are reported, CQI and RI may also be reported as many times as there are CRI(s), or they may be configured / defined to report only the RI / CQI common to some of the CRI(s) (e.g., reporting only one common RI).

[0294] When the proposed method of Example 1 is applied, the operation is described as follows with reference to FIG. 11.

[0295] The base station transmits configuration information related to SRS transmission to the UE (S1102). Here, the configuration information may include various parameters / information related to SRS transmission, and in particular, the configuration information may include information for configuring multiple SRS port groups. Additionally, the configuration information may include information for triggering SRS transmission.

[0296] The UE transmits SRS transmissions to the base station for each SRS port group from each receiving panel (or receiving unit) (S1102).

[0297] The base station transmits CSI-RS to the UE over multiple (beamformed / precoded) CSI-RS resources (S1103).

[0298] The UE reports / transmits the CSI derived from the received CSI-RS to the base station (S1104).

[0299] Here, the UE can calculate / derive / report CSIs assuming that each CW is mapped to a selected CSI-RS resource(s) for each SRS port group (e.g., set of SRS resources) / corresponding SRS port group (e.g., for TDD, the CSI may include a CRI, an SRS port group ID (optional), an RI, a first CQI (for the first CW), and a second CQI (for the second CW).

[0300] If, according to the above-described embodiment, the reporting of the SRS port group ID is omitted (i.e., not included in the CSI), the nth CRI may be reported according to which SRS port group it belongs to, in accordance with an agreement (e.g., configuration / regulation) with the base station. For example, the UE may report to the base station the selected CRIs for the SRS port groups by sequentially including them in the CSI in ascending order of the SRS port group IDs.

[0301] The base station transmits PDSCH to the terminal (S1105).

[0302] Here, the base station can determine / apply a DL MIMO precoder (for PDSCH) by estimating a DL subchannel from the CRI, (SRS port group ID), RI, and CW-specific CQI information received from the UE in step S1104 and the UL subchannel estimation information received from the UE in step S1102 through the SRS port group reception.

[0303] The proposed method(s) of Embodiment 1 described above and the proposed method(s) of Embodiment 2 may be applied together. For example, multiple CSI-RS resources may be configured / transmitted, and a mapping / association between each CSI-RS resource(s) and an SRS port group may be configured / instructed. This case may correspond to a situation where a base station configures / transmits precoded / beamformed CSI-RS through the reception of an SRS port group (e.g., S1102 in FIG. 11), but transmits multiple CSI-RS resources while taking into account channel estimation errors, channel changes, etc. In such a case, when a UE reports N CRIs / CQIs (where N is an integer greater than 0), the terminal does not need to separately report the SRS port group ID in the CSI reporting procedure because it already knows which SRS port group each CRI corresponds to through the base station's configuration / instruction. In the above configuration, N CRIs may be selected and reported regardless of the SRS port group ID to which the terminal is connected, or N CRIs may be selected and reported for each SRS port group. Alternatively, only the minimum number of CRIs to be selected / reported per SRS port group may be configured / defined / instructed, and in this case, the UE may select and report N CRIs according to such configuration / defined / instruction.

[0304] In addition, although the description of this disclosure primarily assumes 2 CW transmissions for Rank > 4 or higher, this is for convenience of explanation and the disclosure is not limited thereto, and can be applied to other ranks and the number of CWs. For example, if multiple layer groups are defined / configured for 1 CW, the operations of this disclosure may be performed on a layer group basis instead of the CW, and in this case, the CW in the description of this disclosure may be replaced by a layer group. Furthermore, in environments where two or more CWs or layer groups are supported in a Rank of 4 or lower, the proposed methods of this disclosure may be applied. Additionally, CSI-RS in this disclosure may be replaced with other DL RSs such as SSB, and CQI may be replaced with other metrics related to channel quality (e.g., L1-RSRP / SINR, etc.). In addition, different precoders are applied to the plurality of (beamformed / precoded) CSI-RS resources / ports (groups), and transmission power (ratio), etc., can also be configured differently according to the receiving panel of the target UE. For example, CSI-RS related EPRE (energy per resource element) ratios (e.g., SSB to CSI-RS EPRE ratio, PDSCH to CSI-RS EPRE ratio, etc.) can be configured individually for each CSI-RS resource / port (group) or SRS port group.

[0305] In relation to the proposed methods of the present disclosure, capability information of a terminal, such as the (maximum) number of SRS port groups supported by the terminal and the (maximum) number of CSI-RS resources / ports, can be transmitted to a base station.

[0306] According to the proposed method of the present disclosure, by separating CSI-RS resource / port(s) for each receiving panel / unit of a low-complexity UE, a base station can transmit CSI-RS with beamforming / power, etc., applied to each receiving panel / unit.

[0307] FIG. 12 is a diagram illustrating the operation of a UE for a channel status information transmission and reception method according to one embodiment of the present disclosure.

[0308] FIG. 12 illustrates the operation of a UE based on the previously proposed method. The example in FIG. 12 is for convenience of explanation and does not limit the scope of the present disclosure. Some step(s) illustrated in FIG. 12 may be omitted depending on the situation and / or configuration. Also, the UE in FIG. 12 is merely an example and may be implemented as the device illustrated in FIG. 3 below. For example, the processor (102 / 202) of FIG. 3 may control the transmission and reception of channels / signals / data / information, etc. using a transceiver (106 / 206), and may also control the storage of channels / signals / data / information, etc. to be transmitted or received in memory (104 / 204).

[0309] Referring to FIG. 12, the UE receives configuration information related to the transmission of a sounding reference signal (SRS) from a base station (S1201).

[0310] Here, the configuration information may include information regarding a first SRS port group and information regarding a second SRS port group. Here, the first SRS port group and the second SRS port group may correspond to different panels (or receiving units, sub-receivers) of the UE. For example, the first / second SRS port group may correspond to one or more SRS resources and may correspond to one or more sets of SRS resources.

[0311] Additionally, the above configuration information may include information for triggering SRS transmission. Alternatively, SRS transmission may be triggered by downlink control information transmitted after the above configuration information.

[0312] The UE transmits SRS transmissions for the first SRS port group and the second SRS port group to the base station based on the above configuration information (S1202).

[0313] In other words, the UE performs SRS transmission to the base station from one or more SRS resources (groups) corresponding to the first SRS port group, or performs SRS transmission from one or more SRS resources (groups) corresponding to the second SRS port group.

[0314] The UE receives CSI-RS from multiple CSI-RS resources from the base station (S1203).

[0315] Here, the UE can receive CSI-RS through multiple antenna ports on multiple CSI-RS resources. For example, the UE can receive CSI-RS through multiple antenna ports on multiple CSI-RS resources based on configuration information related to CSI-RS resources, and in this case, although not shown in FIG. 12, the UE can receive configuration information related to CSI-RS resources from a base station. In this case, configuration information related to CSI-RS resources associated with CSI reports may be included within the configuration information related to CSI reports.

[0316] Here, different beamforming or precoding may be applied to the plurality of CSI-RS resources.

[0317] In addition, different transmission powers may be set for the plurality of CSI-RS resources mentioned above.

[0318] According to an embodiment of the present disclosure, the configuration information related to the SRS transmission may include information regarding a first CSI-RS resource corresponding to the first SRS port group and information regarding a second CSI-RS resource corresponding to the second SRS port group. In this case, the plurality of CSI-RS resources may correspond to the first CSI-RS resource and the second CSI-RS resource.

[0319] The UE transmits the CSI derived using CSI-RS to the base station (S1204).

[0320] Here, channel state information (CSI) (feedback / report) may be transmitted via an uplink physical layer channel (e.g., PUCCH or PUSCH). Additionally, the CSI may include at least one of PMI, CQI, RI, and LI.

[0321] Meanwhile, although not illustrated in FIG. 12, the UE can receive configuration information related to channel state information (CSI) reporting from the base station, and the UE can transmit the CSI to the base station based on the configuration information related to channel state information reporting.

[0322] According to an embodiment of the present disclosure, the CSI may include information related to a first codeword mapped to the first SRS port group and information related to a second codeword mapped to the second SRS port group. In other words, the CSI may include information derived by assuming that the first codeword is mapped / corresponded to the first SRS port group and information derived by assuming that the second codeword is mapped / corresponded to the second SRS port group.

[0323] For example, the above CSI may include RI, a first CQI for the first codeword, and a second CQI for the second codeword. Here, the RI may be the sum of the first RI for the first codeword and the second RI for the second codeword.

[0324] Additionally, the CSI may further include a first CRI indicating a first CSI-RS resource selected for the first SRS port group among the plurality of CSI-RS resources, and a second CRI indicating a second CSI-RS resource selected for the second SRS port group. Here, the CSI may further include an identifier for the first SRS port group and an identifier for the second SRS port group. Additionally, the CSI may further include a first LI for the first codeword and a second LI for the second codeword.

[0325] Additionally, the first CRI and the second CRI may be included in the CSI in the order of the identifiers of the first SRS port group and the second SRS port group. In this case, the CSI may not include the identifier for the first SRS port group and the identifier for the second SRS port group.

[0326] FIG. 13 is a diagram illustrating the operation of a base station for a channel status information transmission and reception method according to one embodiment of the present disclosure.

[0327] FIG. 13 illustrates the operation of a base station based on the previously proposed method. The example in FIG. 13 is for convenience of explanation and does not limit the scope of the present disclosure. Some step(s) illustrated in FIG. 13 may be omitted depending on the situation and / or configuration. Also, the base station in FIG. 13 is merely an example and may be implemented as the device illustrated in FIG. 3 below. For example, the processor (102 / 202) of FIG. 3 may control the transmission and reception of channels / signals / data / information, etc. using a transceiver (106 / 206), and may also control the storage of channels / signals / data / information, etc. to be transmitted or received in a memory (104 / 204).

[0328] Referring to FIG. 13, the base station transmits configuration information related to the transmission of a sounding reference signal (SRS) from the UE (S1301).

[0329] Here, the configuration information may include information regarding a first SRS port group and information regarding a second SRS port group. Here, the first SRS port group and the second SRS port group may correspond to different panels (or receiving units, sub-receivers) of the UE. For example, the first / second SRS port group may correspond to one or more SRS resources and may correspond to one or more sets of SRS resources.

[0330] Additionally, the above configuration information may include information for triggering SRS transmission. Alternatively, SRS transmission may be triggered by downlink control information transmitted after the above configuration information.

[0331] The base station receives SRS transmissions for the first SRS port group and the second SRS port group from the UE based on the above configuration information (S1302).

[0332] In other words, the base station receives an SRS transmission from the UE in one or more SRS resources (groups) corresponding to the first SRS port group, or receives an SRS transmission from one or more SRS resources (groups) corresponding to the second SRS port group.

[0333] The base station transmits CSI-RS from multiple CSI-RS resources to the UE (S1303).

[0334] Here, the base station can transmit CSI-RS to the UE through multiple antenna ports on multiple CSI-RS resources. For example, the base station can transmit CSI-RS through multiple antenna ports on multiple CSI-RS resources based on configuration information related to CSI-RS resources, and in this case, although not shown in FIG. 13, the base station can receive configuration information related to CSI-RS resources from the UE. In this case, configuration information related to CSI-RS resources associated with CSI-RS resources may be included within the configuration information related to CSI-RS resources associated with CSI-RS resources.

[0335] Here, different beamforming or precoding may be applied to the plurality of CSI-RS resources.

[0336] In addition, different transmission powers may be set for the plurality of CSI-RS resources mentioned above.

[0337] According to an embodiment of the present disclosure, the configuration information related to the SRS transmission may include information regarding a first CSI-RS resource corresponding to the first SRS port group and information regarding a second CSI-RS resource corresponding to the second SRS port group. In this case, the plurality of CSI-RS resources may correspond to the first CSI-RS resource and the second CSI-RS resource.

[0338] The base station receives CSI from the UE (S1304).

[0339] Here, channel state information (CSI) (feedback / report) may be transmitted via an uplink physical layer channel (e.g., PUCCH or PUSCH). Additionally, the CSI may include at least one of PMI, CQI, RI, and LI.

[0340] Meanwhile, although not illustrated in FIG. 13, the base station may transmit configuration information related to channel state information (CSI) reporting to the UE, and the base station may receive CSI from the UE based on the configuration information related to channel state information reporting.

[0341] According to an embodiment of the present disclosure, the CSI may include information related to a first codeword mapped to the first SRS port group and information related to a second codeword mapped to the second SRS port group. In other words, the CSI may include information derived by assuming that the first codeword is mapped / corresponded to the first SRS port group and information derived by assuming that the second codeword is mapped / corresponded to the second SRS port group.

[0342] For example, the above CSI may include RI, a first CQI for the first codeword, and a second CQI for the second codeword. Here, the RI may be the sum of the first RI for the first codeword and the second RI for the second codeword.

[0343] Additionally, the CSI may further include a first CRI indicating a first CSI-RS resource selected for the first SRS port group among the plurality of CSI-RS resources, and a second CRI indicating a second CSI-RS resource selected for the second SRS port group. Here, the CSI may further include an identifier for the first SRS port group and an identifier for the second SRS port group. Additionally, the CSI may further include a first LI for the first codeword and a second LI for the second codeword.

[0344] Additionally, the first CRI and the second CRI may be included in the CSI in the order of the identifiers of the first SRS port group and the second SRS port group. In this case, the CSI may not include the identifier for the first SRS port group and the identifier for the second SRS port group.

[0345] The embodiments described above are combinations of the components and features of the present disclosure in a specific form. Each component or feature should be considered optional unless otherwise explicitly stated. Each component or feature may be implemented in a form not combined with other components or features. Additionally, it is possible to construct embodiments of the present disclosure by combining some components and / or features. The order of operations described in the embodiments of the present disclosure may be changed. Some components or features of one embodiment may be included in another embodiment, or may be replaced with corresponding components or features of another embodiment. It is obvious that embodiments may be constructed by combining claims that are not explicitly related in the claims, or that they may be included as new claims by amendment after filing.

[0346] It is obvious to those skilled in the art that the present disclosure may be embodied in other specific forms without departing from the essential features of the present disclosure. Accordingly, the detailed description set forth above should not be interpreted restrictively in all respects and should be considered exemplary. The scope of the present disclosure shall be determined by a reasonable interpretation of the appended claims, and all modifications within the equivalent scope of the present disclosure are included within the scope of the present disclosure.

[0347] The scope of the present disclosure includes software or machine-executable instructions (e.g., operating systems, applications, firmware, programs, etc.) that enable operations according to the methods of various embodiments to be executed on a device or computer, and a non-transitory computer-readable medium on which such software or instructions, etc. are stored and executable on a device or computer. Instructions that may be used to program a processing system to perform the features described in the present disclosure may be stored on or within a storage medium or a computer-readable storage medium, and the features described in the present disclosure may be implemented using a computer program product comprising such a storage medium. The storage medium may include, but is not limited to, high-speed random access memory such as DRAM, SRAM, DDR RAM, or other random access solid-state memory devices, and may include non-volatile memory such as one or more magnetic disk storage devices, optical disk storage devices, flash memory devices, or other non-volatile solid-state storage devices. The memory may optionally include one or more storage devices located remotely from the processor(s). Memory or alternatively, non-volatile memory device(s) within memory comprises a non-transient computer-readable storage medium. The features described in this disclosure may be stored in any one of the machine-readable media and integrated into software and / or firmware that can control the hardware of a processing system and allow the processing system to interact with other mechanisms utilizing results according to the embodiments of this disclosure. Such software or firmware may include, but is not limited to, application code, device drivers, operating systems, and execution environments / containers.

[0348] Here, the wireless communication technology implemented in the device of the present disclosure may include LTE, NR, and 6G, as well as Narrowband Internet of Things for low-power communication. In this case, for example, NB-IoT technology may be an example of LPWAN (Low Power Wide Area Network) technology and may be implemented according to standards such as LTE Cat NB1 and / or LTE Cat NB2, but is not limited to the names mentioned above. Additionally or generally, the wireless communication technology implemented in the device of the present disclosure may perform communication based on LTE-M technology. In this case, for example, LTE-M technology may be an example of LPWAN technology and may be referred to by various names such as eMTC (enhanced Machine Type Communication). For example, LTE-M technology may be implemented in at least one of various standards such as 1) LTE CAT 0, 2) LTE Cat M1, 3) LTE Cat M2, 4) LTE non-BL (non-Bandwidth Limited), 5) LTE-MTC, 6) LTE Machine Type Communication, and / or 7) LTE M, and is not limited to the names mentioned above. Additionally or generally, wireless communication technology implemented in the device (100, 200) of the present disclosure may include at least one of ZigBee, Bluetooth, and Low Power Wide Area Network (LPWAN) for low-power communication, and is not limited to the names mentioned above. As an example, ZigBee technology may create personal area networks (PANs) related to small / low-power digital communication based on various standards such as IEEE 802.15.4, and may be referred to by various names.

[0349] Although the method proposed in this disclosure has been described with an example applied to 3GPP LTE / LTE-A, 5G, and 6G systems, it is possible to apply it to various wireless communication systems in addition to 3GPP LTE / LTE-A, 5G, and 6G systems.

Claims

1. A step in which a user device (UE: user equipment) receives configuration information related to the transmission of a sounding reference signal (SRS: sounding reference signal) from a base station, wherein the configuration information includes information for a first SRS port group and information for a second SRS port group; A step of transmitting the SRS transmission for the first SRS port group and the second SRS port group to the base station by the above UE based on the setting information; The step of receiving CSI-RS from a plurality of channel state information-reference signal (CSI-RS) resources from the base station by the above UE; and The above UE includes the step of transmitting the CSI derived using the CSI-RS to the base station, and A method in which the above CSI includes information related to a first codeword mapped to the first SRS port group and information related to a second codeword mapped to the second SRS port group.

2. In Paragraph 1, The above setting information includes information on a first CSI-RS resource corresponding to the first SRS port group and information on a second CSI-RS resource corresponding to the second SRS port group, and The above plurality of CSI-RS resources are the first CSI-RS resource and the second CSI-RS resource, method.

3. In Paragraph 1, A method comprising the above CSI including a rank indicator (RI), a first channel quality indicator (CQI) for the first codeword, and a second CQI for the second codeword.

4. In Paragraph 3, A method in which the above RI is the sum of the first RI for the first codeword and the second RI for the second codeword.

5. In Paragraph 3, A method comprising: the above CSI further including a first CSI-RS resource indicator (CRI) indicating a first CSI-RS resource selected for a first SRS port group among the plurality of CSI-RS resources, and a second CRI indicating a second CSI-RS resource selected for a second SRS port group.

6. In Paragraph 5, A method in which the above CSI further includes an identifier for the first SRS port group and an identifier for the second SRS port group.

7. In Paragraph 6, A method in which the above CSI further comprises a first layer indicator (LI) for the first codeword and a second LI for the second codeword.

8. In Paragraph 5, A method in which the first CRI and the second CRI are included in the CSI in the order of the identifiers of the first SRS port group and the second SRS port group.

9. In Paragraph 1, A method in which different beamforming or precoding is applied to the plurality of CSI-RS resources.

10. In Paragraph 1, A method in which different transmission powers are set for the plurality of CSI-RS resources.

11. One or more transceivers for transmitting and receiving wireless signals; and It includes one or more processors that control the above one or more transmitting and receiving units, and The above one or more processors are: Receive configuration information related to the transmission of a sounding reference signal (SRS) from a base station, wherein the configuration information includes information for a first SRS port group and information for a second SRS port group; Transmitting the SRS transmission for the first SRS port group and the second SRS port group to the base station based on the setting information; Receiving CSI-RS from a plurality of channel state information-reference signal (CSI-RS) resources from the base station; and The above base station is configured to transmit the CSI derived using the above CSI-RS, and A user device in which the above CSI includes information related to a first codeword mapped to the first SRS port group and information related to a second codeword mapped to the second SRS port group.

12. One or more non-transitory computer-readable media storing one or more instructions, The above one or more instructions are executed by one or more processors, and the user device: Receive configuration information related to the transmission of a sounding reference signal (SRS) from a base station, wherein the configuration information includes information for a first SRS port group and information for a second SRS port group; Transmitting the SRS transmission for the first SRS port group and the second SRS port group to the base station based on the setting information; Receiving CSI-RS from a plurality of channel state information-reference signal (CSI-RS) resources from the base station; and Control the above base station to transmit the CSI derived using the above CSI-RS, and The above CSI is a computer-readable medium comprising information related to a first codeword mapped to the first SRS port group and information related to a second codeword mapped to the second SRS port group.

13. In a processing device configured to control a user device, the processing device comprises: One or more processors; and It includes one or more computer memories that are operably connected to one or more processors and store instructions for performing operations based on execution by one or more processors, and The above operations are: A step of receiving configuration information related to the transmission of a sounding reference signal (SRS) from a base station, wherein the configuration information includes information for a first SRS port group and information for a second SRS port group; A step of transmitting the SRS transmission for the first SRS port group and the second SRS port group to the base station based on the setting information; A step of receiving CSI-RS from a plurality of channel state information-reference signal (CSI-RS) resources from the base station; and The method includes the step of transmitting the CSI derived using the CSI-RS to the base station. A processing device wherein the above CSI includes information related to a first codeword mapped to the first SRS port group and information related to a second codeword mapped to the second SRS port group.

14. A step in which a base station transmits configuration information related to the transmission of a sounding reference signal (SRS) to a user device (UE: user equipment), wherein the configuration information includes information for a first SRS port group and information for a second SRS port group; A step of receiving the SRS transmission for the first SRS port group and the second SRS port group from the UE based on the configuration information by the base station; The step of transmitting CSI-RS from a plurality of channel state information-reference signal (CSI-RS) resources to the UE by the base station; and The above base station includes the step of receiving a CSI derived from the UE using the CSI-RS, and A method in which the above CSI includes information related to a first codeword mapped to the first SRS port group and information related to a second codeword mapped to the second SRS port group.

15. One or more transceivers for transmitting and receiving wireless signals; and It includes one or more processors that control the above one or more transmitting and receiving units, and The above one or more processors are: Transmitting configuration information related to the transmission of a sounding reference signal (SRS) to a user device (UE: user equipment), wherein the configuration information includes information for a first SRS port group and information for a second SRS port group; Receive the SRS transmission for the first SRS port group and the second SRS port group from the above UE based on the above configuration information; Transmit CSI-RS from multiple channel state information-reference signal (CSI-RS) resources to the above UE; It is configured to receive CSI derived from the above UE using the above CSI-RS, and The above CSI is a base station comprising information related to a first codeword mapped to the first SRS port group and information related to a second codeword mapped to the second SRS port group.

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