Method and device for reporting predicted CSI / beam on basis of terminal-initiated reporting scheme in wireless communication system
Patent Information
- Application Number
- PCT/KR2026/004213
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2025-03-19
- Filing Date
- 2026-03-16
- Publication Date
- 2026-09-24
Smart Images

Figure KR2026004213_24092026_PF_FP_ABST
Abstract
Description
Method and apparatus for performing reporting on predicted CSI / beams based on a terminal initiation reporting method in a wireless communication system
[0001] The present disclosure relates to a wireless communication system, and more specifically, to a method and apparatus for performing a report on a predicted CSI / beam based on a reporting method initiated by a terminal 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 performing a report on a predicted CSI / beam based on a reporting method initiated by a terminal in a wireless communication system.
[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 one embodiment of the present disclosure may include: receiving from a base station information that sets an event related to reporting channel state information or beam information for a predicted time interval by a terminal; calculating a measurement value for a channel state or beam based on a measurement resource by the terminal; predicting channel state information or beam information for the predicted time interval based on the measurement value by the terminal to determine whether the conditions for occurrence of the event are satisfied; and transmitting channel state information or beam information for the predicted time interval to the base station by the terminal based on the satisfaction of the conditions for occurrence of the event. Herein, the conditions for occurrence of the event may be defined based on at least one of i) a time domain change amount of a channel state or beam within the predicted time interval or ii) reliability information of the prediction for the predicted time interval.
[0007] A method according to another embodiment of the present disclosure may include: a step of transmitting to a terminal, by a base station, information for setting an event related to reporting channel state information or beam information for a predicted time interval; and a step of receiving channel state information or beam information for a predicted time interval from the terminal by the base station based on the satisfaction of the occurrence condition of the event. Herein, the event may be set such that the terminal calculates a measurement value for a channel state or beam based on a measurement resource, and predicts channel state information or beam information for a predicted time interval based on the measurement value to determine whether the occurrence condition of the event is satisfied. At this time, the occurrence condition of the event may be defined based on at least one of i) a time domain change amount of a channel state or beam within the predicted time interval or ii) reliability information of the prediction for the predicted time interval.
[0008] By various embodiments of the present disclosure, a method and apparatus for reporting on a predicted CSI / beam based on a reporting method initiated by a terminal in a wireless communication system may be provided.
[0009] 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.
[0010] 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.
[0011] FIG. 1 illustrates an exemplary flexible network topology to which some examples of the present disclosure may be applied.
[0012] FIG. 2 illustrates an exemplary communication system to which some examples of the present disclosure may be applied.
[0013] FIG. 3 illustrates an exemplary wireless device to which some examples of the present disclosure may be applied.
[0014] 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.
[0015] FIG. 5 illustrates an exemplary functional framework for AI operations to which some examples of the present disclosure may be applied.
[0016] FIG. 6 illustrates an example of operations related to AI model training and AI model inference to which some examples of the present disclosure may be applied.
[0017] FIG. 7 illustrates another example of operations related to AI model training and AI model inference to which some examples of the present disclosure may be applied.
[0018] FIG. 8 illustrates another example of operations related to AI model training and AI model inference to which some examples of the present disclosure may be applied.
[0019] FIG. 9 shows an electromagnetic spectrum to which some examples of the present disclosure may be applied.
[0020] FIG. 10 illustrates an exemplary system information transmission / reception procedure to which some examples of the present disclosure may be applied.
[0021] FIG. 11 illustrates an exemplary beam management procedure to which some examples of the present disclosure may be applied.
[0022] FIG. 12 shows an example of an NTN scenario to which some examples of the present disclosure may be applied.
[0023] FIG. 13 shows another example of an NTN scenario to which some examples of the present disclosure may be applied.
[0024] FIG. 14 shows examples of sensing operations to which some examples of the present disclosure may be applied.
[0025] FIG. 15 illustrates a multiple TRP (Transmission and Reception Point) transmission method in a wireless communication system to which the present disclosure may be applied.
[0026] FIG. 16 is an example for explaining the operation mode of a terminal start report that can be applied to the present disclosure.
[0027] FIG. 17 illustrates an example of an operation in which a terminal according to an embodiment of the present disclosure determines a prediction beam or a prediction CSI report and performs a report.
[0028] FIG. 18 illustrates another example of an operation in which a terminal according to an embodiment of the present disclosure determines a predicted beam or a predicted CSI report and performs the report.
[0029] FIG. 20 is a drawing for explaining the operation of a second device according to an embodiment of the present disclosure.
[0030] 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.
[0031] 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.
[0032] 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.
[0033] 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.
[0034] 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.
[0035] 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."
[0036] 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."
[0037] 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."
[0038] 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."
[0039] 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."
[0040] In the following explanation, '...when, if, in case of' can be replaced with '...based on'.
[0041] Technical features described individually within one drawing in this disclosure may be implemented individually or simultaneously.
[0042] 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.
[0043] In the present disclosure, the base station (BS, Base Station) may be a second node / IAB node / Transmission-Reception Point (TRP).
[0044] 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.
[0045] 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.
[0046] 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.
[0047] 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) / 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.
[0048] 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.
[0049] Network structure
[0050] FIG. 1 illustrates an exemplary flexible network topology to which some examples of the present disclosure may be applied.
[0051] 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.
[0052] 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.
[0053] 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.
[0054] 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.
[0055] 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.
[0056] 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.
[0057] Systems applicable to the present disclosure
[0058] FIG. 2 illustrates an exemplary communication system to which some examples of the present disclosure may be applied.
[0059] 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).
[0060] 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).
[0061] 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.
[0062] Devices applicable to the present disclosure
[0063] FIG. 3 illustrates an exemplary wireless device to which some examples of the present disclosure may be applied.
[0064] 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).
[0065] 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.
[0066] 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.
[0067] 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.
[0068] 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.
[0069] 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.
[0070] 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).
[0071] 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.
[0072] 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.
[0073] 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.
[0074] 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.
[0075] 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.
[0076] 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.
[0077] 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.
[0078] Communication procedures
[0079] 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.
[0080] 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.
[0081] 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).
[0082] 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 the 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.
[0083] 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 a 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).
[0084] 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.
[0085] 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.
[0086] 6G System Core Technology
[0087] 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.
[0088] artificial intelligence
[0089] 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. 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 machine-to-machine (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.
[0090] FIG. 5 illustrates an exemplary functional framework for AI operations to which some examples of the present disclosure may be applied.
[0091] Below, to provide a more specific explanation of AI (or AI / ML (machine learning)), terms can be defined as follows.
[0092] - Data collection: Data collected from network nodes, management entities, or terminals, serving as a basis for AI model training, data analysis, and inference.
[0093] - 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.
[0094] - 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.
[0095] - AI / ML Inference: A process of making predictions or deriving decisions based on collected data and an AI model using a trained AI model.
[0096] Referring to FIG. 5, the data collection function (10) is a function that collects input data and provides processed input data to the model training function (20) and the model inference function (30).
[0097] Examples of input data may include measurements from terminals or other network entities, feedback from actors, and outputs from AI models.
[0098] The data collection function (10) performs data preparation based on input data and provides the input data processed through data preparation. Here, the data collection function (10) does not perform specific data preparation (e.g., data pre-processing and cleaning, forming and transformation) for each AI algorithm, and can perform data preparation common to AI algorithms.
[0099] After the data preparation process is performed, the data collection function (10) can provide training data (11) to the model training function (20) and provide inference data (12) to the model inference function (30). Here, the training data (11) corresponds to data required as input for the AI model training function (20), and the inference data (12) corresponds to data required as input for the AI model inference function (30).
[0100] The data collection function (10) may be performed by a single entity (e.g., terminal, RAN node, network node, etc.) but may also be performed by multiple entities. In this case, training data (11) and inference data (12) from multiple entities may be provided to the model training function (20) and the model inference function (30), respectively.
[0101] The model training function (20) may correspond to a function that performs AI model training, validation, and testing, which can generate model performance metrics as part of the AI model testing procedure. If necessary, the model training function (20) may also be responsible for data preparation (e.g., data pre-processing and cleaning, formatting and transformation, etc.) based on training data (11) provided by the data collection function (10).
[0102] Here, model deployment / update (13) can be used to initially deploy a trained, validated, and tested AI model to the model inference function (30) or to provide an updated model to the model inference function (30).
[0103] The model inference function (30) may correspond to a function that provides an AI model inference output (16) (e.g., a prediction or a decision). The model inference function (30) may provide model performance feedback (14) to the model training function (20) where applicable. Additionally, the model inference function (30) may be responsible for data preparation (e.g., data pre-processing and cleaning, formatting and transformation, etc.) based on the inference data (12) provided by the data collection function (10) if necessary.
[0104] Here, output (16) refers to the inference output of an AI model generated by the model inference function (30), and the details of the inference output may vary depending on the use case.
[0105] Model performance feedback (14) can be used to monitor the performance of the AI model if available, and this feedback may be omitted.
[0106] The actor function (40) is a function that receives an output (16) from the model inference function (30) and triggers or performs a corresponding operation / action. The actor function (40) can trigger an operation / action on another entity (e.g., one or more terminals, one or more RAN nodes, one or more network nodes, etc.) or on itself.
[0107] Feedback (15) can be used to derive training data (11) and inference data (12), or to monitor the performance of the AI model, the impact on the network, etc.
[0108] Meanwhile, the definitions of training, validation, and testing in data sets used in AI / ML can be distinguished as follows.
[0109] - Training data: Refers to the dataset used to train a model.
[0110] - Validation data: This refers to a dataset used to validate a model that has already been trained. Validation data typically refers to a dataset used to prevent overfitting of the training dataset. Additionally, validation data can refer to a dataset used to select the best model among the various models trained during the learning process. Therefore, validation can be viewed as a type of training.
[0111] - Test data: Refers to the dataset for final evaluation. This data is unrelated to training.
[0112] For example, within the entire dataset, training data and validation data can be divided in a ratio of approximately 8:2 or 7:3. Alternatively, within the entire dataset, training data:validation data:test data can be divided in a ratio of 6:2:2.
[0113] Depending on whether the base station and the terminal possess the capability for AI / ML functions, the cooperation level can be defined as follows, and variations resulting from the combination of multiple levels below or the separation of any one level are also possible.
[0114] Category 0a: This corresponds to a no collaboration framework. In this case, the AI / ML algorithm is based on pure implementation and may not require changes to the wireless interface.
[0115] Category 0b: Corresponds to a framework that involves a wireless interface modified to fit efficient implementation-based AI / ML algorithms but lacks cooperation.
[0116] Category 1: This applies to cases involving inter-node support to improve the AI / ML algorithms of each node. For example, it applies when a terminal receives support from a base station (for training, adaptation, etc.), and vice versa. At this level, model exchange between network nodes is not required.
[0117] Category 2: This applies to cases where joint ML operations between a terminal and a base station can be performed. This level requires AI / ML model commands or exchanges between network nodes.
[0118] The functions exemplified in Figure 5 above may be implemented at RAN nodes (e.g., base station, TRP, base station CU, etc.), network nodes, network operator's OAM (operation administration maintenance), or terminals.
[0119] Alternatively, two or more entities among a RAN, a network node, a network operator's OAM, or a terminal may cooperate to implement the functions exemplified in FIG. 5. For example, one entity may perform some of the functions of FIG. 5, and another entity may perform the remaining functions. As such, some of the functions exemplified in FIG. 5 are performed by a single entity (e.g., a terminal, a RAN node, a network node, etc.), the transmission / provision of data / information between each function may be omitted. For example, if the model training function (20) and the model inference function (30) are performed by the same entity, the transmission / provision of model distribution / update (13) and model performance feedback (14) may be omitted.
[0120] Alternatively, any one of the functions exemplified in FIG. 5 may be performed by two or more entities among the RAN, network node, network operator's OAM, or terminal in collaboration. This may be referred to as a split AI operation.
[0121] FIG. 6 illustrates an example of operations related to AI model training and AI model inference to which some examples of the present disclosure may be applied.
[0122] For example, the AI model training function can be performed by network nodes (e.g., core network nodes, network operator's OAM, etc.), and the AI model inference function can be performed by RAN nodes (e.g., base station, TRP, base station's CU, etc.).
[0123] Step 1: RAN Node 1 and RAN Node 2 can transmit input data (e.g., training data) for training an AI model to a network node. Here, RAN Node 1 and RAN Node 2 can also transmit data collected from terminals to the network node (e.g., terminal measurements related to RSRP (reference signal received power), RSRQ (reference signal received quality), and SINR (signal to interference-plus-noise ratio) of the serving cell and neighboring cells, terminal location, speed, etc.).
[0124] Step 2: Network nodes can train AI models using the received training data.
[0125] Step 3: The network node can distribute / update the AI model to RAN Node 1 and / or RAN Node 2. RAN Node 1 (and / or RAN Node 2) may also continue model training based on the received AI model.
[0126] For the sake of convenience of explanation, it is assumed that the AI model was deployed / updated only to RAN Node 1.
[0127] Step 4: RAN Node 1 can receive input data (e.g., inference data) for AI model inference from the terminal and RAN Node 2.
[0128] Step 5: RAN Node 1 can perform AI model inference using the received inference data to generate output data (e.g., prediction or decision).
[0129] Step 6: If applicable, RAN node 1 can send model performance feedback to network nodes.
[0130] Step 7: RAN Node 1, RAN Node 2, and the terminal (or 'RAN Node 1 and the terminal', or 'RAN Node 1 and RAN Node 2') can perform an action based on the output data. For example, in the case of a load balancing action, the terminal may move from RAN Node 1 to RAN Node 2.
[0131] Step 8: RAN Node 1 and RAN Node 2 can transmit feedback information to network nodes.
[0132] FIG. 7 illustrates another example of operations related to AI model training and AI model inference to which some examples of the present disclosure may be applied.
[0133] For example, both AI model training and AI model inference functions can be performed by RAN nodes (e.g., base station, TRP, base station's CU, etc.).
[0134] Step 1: The terminal and RAN node 2 can transmit input data (e.g., training data) for training an AI model to RAN node 1.
[0135] Step 2: RAN Node 1 can train an AI model using the received training data.
[0136] Step 3: RAN Node 1 can receive input data (e.g., inference data) for AI model inference from the terminal and RAN Node 2.
[0137] Step 4: RAN Node 1 can perform AI model inference using the received inference data to generate output data (e.g., prediction or decision).
[0138] Step 5: RAN Node 1, RAN Node 2, and the terminal (or 'RAN Node 1 and the terminal', or 'RAN Node 1 and RAN Node 2') can perform an action based on the output data. For example, in the case of a load balancing action, the terminal may move from RAN Node 1 to RAN Node 2.
[0139] Step 6: RAN Node 2 can send feedback information to RAN Node 1.
[0140] FIG. 8 illustrates another example of operations related to AI model training and AI model inference to which some examples of the present disclosure may be applied.
[0141] For example, the AI model training function may be performed by a RAN node (e.g., base station, TRP, base station CU, etc.), and the AI model inference function may be performed by a terminal.
[0142] Step 1: A terminal can transmit input data (e.g., training data) for training an AI model to a RAN node. Here, the RAN node can collect data (e.g., terminal measurements related to RSRP, RSRQ, SINR of the serving cell and neighboring cells, terminal location, velocity, etc.) from various terminals and / or other RAN nodes.
[0143] Step 2: The RAN node can train an AI model using the received training data.
[0144] Step 3: The RAN node can distribute / update the AI model to the terminal. The terminal may also continue model training based on the received AI model.
[0145] Step 4: Input data (e.g., inference data) for AI model inference can be received from terminals and RAN nodes (and / or other terminals).
[0146] Step 5: The terminal can perform AI model inference using the received inference data to generate output data (e.g., prediction or decision).
[0147] Step 6: If applicable, the terminal can transmit model performance feedback to the RAN node.
[0148] Step 7: The terminal and the RAN node can perform actions based on the output data.
[0149] Step 8: The terminal can transmit feedback information to the RAN node.
[0150] THz communication
[0151] 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.
[0152] FIG. 9 shows an electromagnetic spectrum to which some examples of the present disclosure may be applied.
[0153] 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.
[0154] 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.
[0155] FIG. 10 illustrates an exemplary system information transmission / reception procedure to which some examples of the present disclosure may be applied.
[0156] The example of FIG. 10 is applicable not only to THz communication environments but also to 6G communication environments where THz communication is not applied. In addition, the procedure exemplified in FIG. 10 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 exemplified in FIG. 10.
[0157] In step S1010, 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.
[0158] In step S1030, 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 of cell #1 is received in cell #2, the acquisition of synchronization for cell #1 can be performed after receiving system information. For example, the terminal can acquire synchronization based on system information. Alternatively, the acquisition of synchronization may be performed prior to step S1010.
[0159] In step S1050, 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) may 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.
[0160] The procedure described with reference to FIG. 10 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).
[0161] 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.
[0162] FIG. 11 illustrates an exemplary beam management procedure to which some examples of the present disclosure may be applied.
[0163] Figure 11 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.
[0164] 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.
[0165] In step S1110, the second node (120) (e.g., base station) may set resources for beam management to the first node (110) (e.g., 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 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.
[0166] In step S1130, 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).
[0167] In step S1150, 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 S1130.
[0168] In step S1170, 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 S1150. If channel reciprocity is established, the transmission beam of the first node (110) can also be determined through steps S1130 and S1150, 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 S1150. 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).
[0169] Non-terrestrial networks (NTN)
[0170] FIGS. 12 and FIGS. 13 show examples of NTN scenarios to which some examples of the present disclosure may be applied.
[0171] NTN can represent a network or network segment that uses RF (radio frequency) resources mounted on a satellite (or UAS (unmanned aerial system) platform).
[0172] Figure 12 shows an example of a typical scenario of an NTN based on a transparent payload, and Figure 13 shows an example of a typical scenario of an NTN based on a regenerative payload.
[0173] Referring to FIG. 12, the satellite (or UAS platform) can establish a service link with a terminal. The satellite (or UAS platform) can be connected to a gateway via a feeder link. The satellite can be connected to a data network via the gateway. A beam footprint may refer to an area where signals transmitted by the satellite can be received.
[0174] Referring to FIG. 13, a satellite (or UAS platform) can establish a service link with a terminal. The satellite (or UAS platform) connected to the terminal can be connected to another satellite (or UAS platform) via inter-satellite links (ISL). Another satellite (or UAS platform) can be connected to a gateway via a feeder link. Based on a regenerated payload, the satellite can be connected to a data network via another satellite and a gateway. If no ISL exists between the satellite and another satellite, a feeder link between the satellite and the gateway may be required.
[0175] FIGS. 12 and 13 are merely examples of NTN scenarios, and NTN can be implemented based on various scenarios. For example, a satellite (or UAS platform) can implement a transparent or regenerative (with on-board processing) payload. For example, a satellite (or UAS platform) can generate multiple beams across a designated service area depending on the field of view of the satellite (or UAS platform). For example, the field of view of the satellite (or UAS platform) may vary depending on the on-board antenna diagram and the minimum elevation angle.
[0176] For example, the transparent payload may include radio frequency filtering, frequency conversion, and amplification. Therefore, the waveform signal repeated by the payload may not be altered.
[0177] For example, the regeneration payload may include radio frequency filtering, frequency conversion and amplification, demodulation / decoding, switching and / or routing, and coding / modulation. For example, the regeneration payload may be substantially the same as carrying all or part of the base station functions on a satellite (or UAS platform).
[0178] Integrated Sensing and Communication (ISAC)
[0179] Wireless sensing is a technology that uses radio frequencies to determine the instantaneous linear velocity, angle, distance (or range) of an object, thereby obtaining information about the characteristics of the environment and / or objects within the environment. Since radio frequency sensing capabilities do not require connecting to objects via devices within a network, they can provide services for determining object locations without the need for devices. The ability to obtain range, velocity, and angle information from radio frequency signals can provide a wide range of new functions, such as various object detection, object recognition (e.g., vehicles, humans, animals, UAVs), high-precision localization, tracking, and activity recognition. Wireless sensing services can provide information to various industries (e.g., unmanned aerial vehicles, smart homes, V2X, factories, railways, public safety, etc.) that enable applications such as intruder detection, assisted vehicle steering and navigation, trajectory tracking, collision avoidance, traffic management, and health and traffic management. In some cases, wireless sensing may utilize non-3GPP type sensors (e.g., radar, cameras) to further support 3GPP-based sensing. For example, the operation of a wireless sensing service, such as sensing operations, may depend on the transmission, reflection, and scattering processing of wireless sensing signals. Therefore, wireless sensing can provide an opportunity to enhance existing communication systems from communication networks to wireless communication and sensing networks.
[0180] FIG. 14 shows examples of sensing operations to which some examples of the present disclosure may be applied.
[0181] Specifically, FIG. 14(a) illustrates an example of monostatic sensing operation using a sensing receiver and a sensing transmitter located at the same position. FIG. 14(b) illustrates an example of bistatic sensing operation using a sensing receiver and a sensing transmitter located at separate positions. A sensing receiver receives a signal that is reflected or scattered by a sensing object from a sensing signal transmitted from a sensing transmitter, and can extract or acquire sensing data based on the received signal. A sensing result can be generated or determined through appropriate processing of this sensing data. The sensing result can be provided to a trusted third-party entity or service outside the 3GPP system via an entity or service within the 3GPP system.
[0182] Multiple TRP (M-TRP) related operations
[0183] FIG. 15 illustrates a multiple TRP transmission method in a wireless communication system to which the present disclosure may be applied.
[0184] Referring to FIG. 15(a), it shows a case where layer groups transmitting the same codeword (CW) / transport block (TB) correspond to different TRPs. In this case, a layer group may refer to a set of layers consisting of one or more layers. In this case, the amount of transmission resources increases due to the number of layers, which has the advantage of allowing robust channel coding with a low code rate for the TB. Additionally, since the channels differ from the multiple TRPs, the reliability of the received signal can be expected to improve based on diversity gain.
[0185] Referring to FIG. 15(b), an example is shown in which different CWs are transmitted through layer groups corresponding to different TRPs. In this case, it can be assumed that the TBs corresponding to CW #1 and CW #2 in the figure are identical. That is, CW #1 and CW #2 each represent the same TB that has been converted into different CWs through channel coding, etc., by different TRPs. Therefore, this can be viewed as an example of repeated transmission of the same TB. In the case of FIG. 15(b), compared to FIG. 15(a) mentioned earlier, there may be a disadvantage in that the code rate corresponding to the TB is high. However, it has the advantage of being able to adjust the code rate by indicating different RV (redundancy version) values for the encoded bits generated from the same TB depending on the channel environment, or to adjust the modulation order of each CW.
[0186] According to the method exemplified in Figures 15 (a) and (b) above, the same TB is repeatedly transmitted through different layer groups, and as each layer group is transmitted by different TRPs / panels, the probability of data reception by the terminal can be increased. This is referred to as the SDM (Spatial Division Multiplexing) based M-TRP URLLC transmission method. Layers belonging to different layer groups are each transmitted through DMRS ports belonging to different DMRS CDM groups.
[0187] In addition, although the above description regarding multiple TRPs was explained based on the spatial division multiplexing (SDM) method using different layers, it goes without saying that this can be extended and applied to the frequency division multiplexing (FDM) method based on different frequency domain resources (e.g., RB / PRB (set), etc.) and / or the time division multiplexing (TDM) method based on different time domain resources (e.g., slot, symbol, sub-symbol, etc.).
[0188] Regarding techniques for multi-TRP-based URLLCs scheduled by a single DCI, the following techniques are being discussed.
[0189] 1) Technique 1 (SDM): Time and frequency resource allocations overlap, and n (n<=Ns) TCI states within a single slot
[0190] 1-a) Technique 1a
[0191] - At each transmission occasion, the same TB is transmitted from one layer or set of layers, and each layer or set of layers is associated with one set of TCI and one DMRS port(s).
[0192] - A single codeword with a single RV is used in all spatial layers or a set of all layers. From the UE perspective, different coded bits are mapped to different layers or a set of layers using the same mapping rules.
[0193] 1-b) Technique 1b
[0194] - At each transmission occasion, the same TB is transmitted from one layer or set of layers, and each layer or set of layers is associated with one set of TCI and one set of DMRS ports.
[0195] - A single codeword with a single RV is used in each spatial layer or in the set of each layer. The RV(s) corresponding to each spatial layer or the set of each layer may be the same or different.
[0196] 1-c) Technique 1c
[0197] - At one transmission occasion, the same TB having one DMRS port associated with multiple TCI state indices is transmitted in one layer, or the same TB having multiple DMRS ports associated one-to-one with multiple TCI state indices is transmitted in one layer.
[0198] In the case of the aforementioned techniques 1a and 1c, the same MCS is applied to all layers or all sets of layers.
[0199] 2) Technique 2 (FDM): Frequency resource allocations do not overlap, and there are n (n<=Nf) TCI states within a single slot.
[0200] - Each non-overlapping frequency resource allocation is associated with one TCI state.
[0201] - The same single / multiple DMRS port(s) are associated with all non-overlapping frequency resource allocations.
[0202] 2-a) Technique 2a
[0203] - A single codeword with a single RV is used for all resource allocations. From the UE's perspective, common RB matching (mapping of codewords to layers) is applied in all resource allocations.
[0204] 2-b) Technique 2b
[0205] A single codeword with a single RV is used for each non-overlapping frequency resource allocation. The RVs corresponding to each non-overlapping frequency resource allocation may be the same or different.
[0206] For the aforementioned technique 2a, the same MCS is applied to all non-overlapping frequency resource allocations.
[0207] 3) Technique 3 (TDM): Time resource allocations do not overlap, and n (n<=Nt1) TCI states within a single slot
[0208] - Each transmission occasion of TB has mini-slot time granularity and has one TCI and one RV.
[0209] - A common MCS is used with a single or multiple DMRS port(s) at every transmission occasion within the slot.
[0210] - RV / TCI can be the same or different at different transmission occasions.
[0211] 4) Technique 4 (TDM): n (n<=Nt2) TCI states in K (n<=K) different slots
[0212] - Each transmission occasion of TB has one TCI and one RV.
[0213] - All transmission occasions across K slots use a common MCS with a single or multiple DMRS port(s).
[0214] - RV / TCI can be the same or different at different transmission occasions.
[0215] Downlink Multiple TRP (M-TRP) URLLC Transport Operation
[0216] The DL M-TRP URLLC transmission method refers to a method in which multiple TRPs transmit the same data / DCI using different spatial (e.g., layer / port) / time / frequency resources. For example, TRP 1 can transmit specific data / DCI from resource 1, and TRP 2 can transmit the said specific data / DCI (i.e., the same data / DCI) from resource 2.
[0217] That is, when the DL M-TRP URLLC transmission method is configured, the terminal can receive the same data / DCI using different spatial / temporal / frequency resources. At this time, the terminal can receive instructions from the base station regarding the QCL RS / type (i.e., DL TCI status) used in the spatial / temporal / frequency resources receiving the data / DCI.
[0218] For example, if the data / DCI is received from resource 1 and resource 2, the terminal may be instructed by the base station on the DL TCI status used in resource 1 and the DL TCI status used in resource 2. By receiving the data / DCI through resource 1 and resource 2, high reliability can be achieved. This M-TRP URLLC transmission method can be applied to PDSCH / PDCCH.
[0219] The UL M-TRP URLLC transmission method refers to a method in which multiple TRPs receive the same data / UCI from a single terminal using different spatial, temporal, and frequency resources. For example, TRP 1 can receive the same data / UCI from the terminal at resource 1, and TRP 2 can receive the same data / UCI from the terminal at resource 2. Additionally, TRP 1 and TRP 2 can share the data / UCI received from the terminal through a backhaul link (connected between the TRPs).
[0220] That is, when the UL M-TRP URLLC transmission method is configured, the terminal can transmit the same data / UCI to each TRP using different spatial / temporal / frequency resources. In this case, the terminal can receive instructions from the base station regarding the Tx beam and Tx power (i.e., UL TCI state) to be used in the spatial / temporal / frequency resources transmitting the same data / UCI. For example, if the same data / UCI is transmitted from Resource 1 and Resource 2, the terminal can receive instructions from the base station regarding the UL TCI state used in Resource 1 and the UL TCI state used in Resource 2. Such UL M-TRP URLLC can be applied to PUSCH / PUCCH.
[0221] In addition, in describing the present disclosure, when receiving / transmitting data / DCI / UCI through a specific space / time / frequency resource, using (or mapping) a specific TCI state (or TCI) may mean, in the case of DL, estimating a channel from DMRS using a QCL type and QCL RS indicated by a specific TCI state in a specific space / time / frequency resource, and receiving / demodulating data / DCI / UCI through the estimated channel.
[0222] And, when receiving / transmitting data / DCI / UCI through a specific space / time / frequency resource, using (or mapping) a specific TCI state (or TCI) may mean, in the case of UL, transmitting / modulating DMRS and data / UCI using the Tx beam and / or Tx power indicated by the specific TCI state in the specific space / time / frequency resource.
[0223] In addition, the UL TCI status may include the terminal's Tx beam or Tx power information. In addition, the base station may set spatial relation information, etc., for the terminal through other parameters instead of the TCI status.
[0224] For example, the UL TCI status may be indicated directly to the terminal via the UL grant DCI. Alternatively, the UL TCI status may refer to spatial relationship information of SRS resources indicated via the SRI (SRS resource indicator) field of the UL grant DCI. Alternatively, the UL TCI status may refer to an open loop (OP) Tx power control parameter associated with a value indicated via the SRI field of the UL grant DCI.
[0225] Here, the OL Tx power control parameters may include, for example, j (an index for the OP parameter(s) Po and alpha (a set of up to 32 parameter values per cell), q_d (an index of the DL RS resource for the PL (path loss) measurement (up to 4 measurements per cell), or / and I (a closed-loop power control process index (up to 2 processes per cell)).
[0226] In another embodiment of the present disclosure, the M-TRP eMBB transmission method refers to a method in which M-TRP transmits different data / DCIs using different spatial / temporal / frequency resources. When the M-TRP eMBB transmission method is configured, the terminal may be instructed by a plurality of TCI states from a base station via the DCI, and it may be assumed that the received data is different data by using the QCL RS indicated by each of the plurality of TCI states.
[0227] In addition, since the RNTI for M-TRP URLLC and the RNTI for M-TRP eMBB are used separately, the terminal can determine whether a specific transmission is an M-TRP URLLC transmission or an M-TRP eMBB transmission. For example, if the RNTI for URLLC is used to mask the DCI with CRC, the terminal can identify the transmission as a URLLC transmission. And, if the RNTI for eMBB is used to mask the DCI with CRC, the terminal can identify the transmission as an eMBB transmission. As another example, the base station can set the M-TRP URLLC transmission / reception method or the M-TRP eMBB transmission / reception method for the terminal through new signaling.
[0228] For convenience of explanation of the present disclosure, it has been assumed that two TRPs cooperate to perform transmission / reception operations, but this is not limited thereto. That is, the present disclosure is applicable to environments with three or more TRPs, and is also applicable to environments where transmission / reception occurs to different panels or beams from the same TRP. A terminal may recognize different TRPs as different TCI states. That a terminal transmits / DCI / UCI using TCI state 1 means that it transmits / DCI / UCI from (or to) TRP 1.
[0229] The present disclosure can be utilized in situations where an M-TRP cooperatively transmits a PDCCH (repeating or splitting the same PDCCH). Additionally, the present disclosure can be utilized in situations where an M-TRP cooperatively transmits a PDSCH or cooperatively receives a PUSCH / PUCCH.
[0230] Furthermore, in describing the present disclosure, the meaning that multiple base stations (i.e., M-TRPs) repeatedly transmit the same PDCCH may mean that the same DCI is transmitted through multiple PDCCH candidates, and is equivalent to the meaning that multiple base stations repeatedly transmit the same DCI. Here, two DCIs with the same DCI format, size, and payload may be considered as identical DCIs.
[0231] Alternatively, even if the payloads of the two DCIs are different, if the scheduling results are identical, the two DCIs can be regarded as the same DCI. For example, the time domain resource allocation (TDRA) field of a DCI can determine the slot / symbol positions of the data and the slot / symbol positions of A(ACK) / N(NACK) relatively based on the time of reception of the DCI.
[0232] In this case, if the DCI received at time n and the DCI received at time n+1 instruct the terminal to have the same scheduling result, the TDRA fields of the two DCIs will differ, and consequently, their DCI payloads will differ. Therefore, even if the payloads of the two DCIs are different, if the scheduling result is the same, the two DCIs can be considered the same DCI. Here, the number of iterations R can be directly instructed by the base station to the terminal or mutually agreed upon.
[0233] Alternatively, even if the payloads of two DCIs are different and their scheduling results are not identical, if the scheduling result of one DCI is a subset of the scheduling result of another DCI, the two DCIs can be considered the same DCI.
[0234] For example, if the same data is TDMed and transmitted N times, DCI 1 received before the first data directs (or schedules) the data to be repeated N times, and DCI 2 received before the second data directs (scheduls) the data to be repeated N-1 times. In this case, the scheduling result (or data) of DCI 2 becomes a subset of the scheduling result (or data) of DCI 1, and both DCIs have scheduling results for the same data. Therefore, even in this case, the two DCIs can be considered the same DCI.
[0235] And, in describing the present disclosure, the statement that a plurality of base stations (i.e., M-TRPs) share and transmit the same PDCCH may mean that one DCI is transmitted through one PDCCH candidate, where TRP 1 transmits some resources defined for the PDCCH candidate and TRP 2 transmits the remaining resources.
[0236] For example, when TRP 1 and TRP 2 divide and transmit PDCCH candidates corresponding to aggregation levels m1 + m2, the PDCCH candidates are divided into PDCCH candidate 1 corresponding to aggregation level m1 and PDCCH candidate 2 corresponding to aggregation level m2, and TRP 1 transmits PDCCH candidate 1 and TRP 2 transmits PDCCH candidate 2. In this case, TRP 1 and TRP 2 may transmit PDCCH candidate 1 and PDCCH candidate 2 using different time / frequency resources. After receiving PDCCH candidate 1 and PDCCH candidate 2, the terminal may generate a PDCCH candidate corresponding to aggregation level m1+m2 and attempt DCI decoding.
[0237] At this time, the method of dividing and transmitting the same DCI to multiple PDCCH candidates can be implemented in the following two ways.
[0238] The first method involves encoding the DCI payload (e.g., control information + CRC) through a single channel encoder (e.g., a polar encoder) and dividing it among two TRPs for transmission. In other words, the first method refers to a process where the coded bits obtained based on the encoding result are divided and transmitted among the two TRPs. Here, the entire DCI payload may be encoded in the coded bits transmitted by each TRP, but this is not limited to this, and only a portion of the DCI payload may be encoded.
[0239] The second method is to divide the DCI payload (e.g., control information + CRC) into two DCIs (e.g., DCI 1 and DCI 2) and then encode each through a channel encoder (e.g., a polar encoder). Afterward, each of the two TRPs can transmit the coded bits corresponding to DCI 1 and the coded bits corresponding to DCI 2 to the terminal.
[0240] That is, the meaning that multiple base stations (M-TRPs) divide / repeat the same PDCCH and transmit it over multiple monitoring occasions (MOs) may mean: 1) that the coded bits encoding the entire DCI content of the PDCCH are repeatedly transmitted through each MO for each base station (S-TRP); 2) that the coded bits encoding the entire DCI content of the PDCCH are divided into multiple parts, and that each base station (S-TRP) transmits a different part through each MO; or 3) that the DCI content of the PDCCH is divided into multiple parts, and that each base station (S-TRP) encodes a different part (i.e., separate encoding) and transmits it through each MO.
[0241] Repeating or splitting the transmission of PDCCH can be understood as transmitting the PDCCH multiple times across several TOs (transmission occasions).
[0242] Here, TO may refer to a specific time or / and frequency resource unit in which the PDCCH is transmitted. For example, if the PDCCH is transmitted multiple times across slots 1, 2, 3, and 4 (to a specific RB), TO may refer to each slot. As another example, if the PDCCH is transmitted multiple times across RB sets 1, 2, 3, and 4 (in a specific slot), TO may refer to each RB set. As yet another example, if the PDCCH is transmitted multiple times across different times and frequencies, TO may refer to each time / frequency resource. Additionally, the TCI state used for DMRS channel estimation may be set differently for each TO, and TOs with different TCI states can be assumed to have been transmitted by different TRPs / panels.
[0243] The fact that multiple base stations repeatedly transmit or split the PDCCH means that the PDCCH is transmitted across multiple TOs, and the union of the TCI states set in the corresponding TOs consists of two or more TCI states. For example, if the PDCCH is transmitted across TOs 1, 2, 3, and 4, TCI states 1, 2, 3, and 4 may be set in each of TOs 1, 2, 3, and 4, which means that TRP i has cooperatively transmitted the PDCCH from TO i.
[0244] In describing the present disclosure, the fact that a terminal repeatedly transmits the same PUSCH to a plurality of base stations (i.e., M-TRP) may mean that the terminal has transmitted the same data through a plurality of PUSCHs, and each PUSCH may be optimized for transmission to the UL channel of a different TRP.
[0245] For example, a terminal can repeatedly transmit the same data via PUSCH 1 and PUSCH 2. In this case, PUSCH 1 is transmitted using UL TCI state 1 for TRP 1, and the PUSCH can be transmitted by scheduling values optimized for the TRP 1 channel for link adaptation, such as a precoder / MCS. PUSCH 2 is transmitted using UL TCI state 2 for TRP 2, and the PUSCH can be transmitted by scheduling values optimized for the TRP 2 channel for link adaptation, such as a precoder / MCS. In this case, the repeatedly transmitted PUSCH 1 and PUSCH 2 can be transmitted at different times and can be TDM, FDM, or SDM.
[0246] In addition, in describing the present disclosure, the statement that a terminal divides and transmits the same PUSCH to multiple base stations (i.e., M-TRPs) may mean that one data is transmitted through one PUSCH, but the resources allocated to that PUSCH are divided and optimized for transmission to the UL channels of different TRPs.
[0247] For example, the terminal can transmit the same data via a 10-symbol PUSCH. In this case, the first 5 symbols of the 10 symbols can be transmitted using UL TCI state 1 for TRP 1, and the terminal can transmit the 5-symbol PUSCH (to TRP 1) by scheduling values optimized for the TRP 1 channel, such as a precoder / MCS and link adaptives. The remaining 5 symbols can be transmitted using UL TCI state 2 for TRP 2, and the terminal can transmit the remaining 5-symbol PUSCH (to TRP 2) by scheduling values optimized for the TRP 2 channel, such as a precoder / MCS and link adaptives.
[0248] In the above example, a method of dividing a single PUSCH into time resources to perform TDM transmission to TRP 1 and transmission to TRP 2 was described, but the present disclosure is not limited thereto, and the terminal may divide and transmit the same PUSCH to multiple base stations by using an FDM / SDM method.
[0249] The terminal can repeatedly transmit a PUCCH to multiple base stations (similar to PUSCH transmission) or divide and transmit the same PUCCH.
[0250] In addition, when multiple TOs are instructed to a terminal to transmit PDCCH / PDSCH / PUSCH / PUCCH repeatedly or in separate transmissions, each TO may transmit a UL toward a specific TRP or receive a DL from a specific TRP. In this case, the UL TO transmitted toward TRP 1 (or the TO of TRP 1) may refer to a TO using the first value among two spatial relations, two UL TCIs, two UL power control parameters, or two PL (pathloss)-RSs instructed to the terminal. And, the UL TO transmitted toward TRP 2 (or the TO of TRP 2) refers to a TO using the second value among two spatial relations, two UL TCIs, two UL power control parameters, and two PL-RSs instructed to the terminal.
[0251] Similarly, when transmitting DL, the DL TO transmitted by TRP 1 (or the TO of TRP 1) refers to a TO using the first value of the two DL TCI states instructed to the terminal (e.g., when two TCI states are set in CORESET), and the DL TO transmitted by TRP 2 (or the TO of TRP 2) may refer to a TO using the second value of the two DL TCI states instructed to the terminal (e.g., when two TCI states are set in CORESET).
[0252] The present disclosure can be extended to various channels such as PUSCH / PUCCH / PDSCH / PDCCH. Furthermore, the present disclosure can be extended to both cases where the channel is transmitted repeatedly over different spatial / temporal / frequency resources and cases where it is transmitted in segments.
[0253] In addition, from the perspective of DCI transmission, M-TRP transmission methods can be divided into i) M-DCI (multiple DCI) based M-TRP transmission methods, where each TRP transmits different DCIs, and ii) S-DCI (single DCI) based M-TRP transmission methods, where a single TRP transmits a DCI. For example, in the case of S-DCI, since all scheduling information for the data transmitted by the M-TRP must be conveyed through a single DCI, it can be used in an ideal BackHaul (BH) environment where dynamic cooperation between two TRPs is possible.
[0254] Improved M-TRP transmission and reception
[0255] Regarding M-TRP transmission and reception in Rel-16 NR standardization, PDSCH transmission and reception based on S-DCI-based M-TRP transmission and M-DCI-based M-TRP transmission are supported.
[0256] First, we will examine the S-DCI-based M-TRP PDSCH transmission method.
[0257] S-DCI-based M-TRP PDSCH transmission may utilize one of the SDM, FDM, or TDM methods. In the case of SDM, the base station transmits a single TB using multiple layers, but layers belonging to different DMRS CDM groups are transmitted via different transmission beams (Tx beams) (i.e., QCL RS or TCI states). This allows for an increase in the number of layers compared to the existing S-TRP transmission method, thereby improving transmission capacity. Additionally, when a single TB is transmitted using multiple layers, some layers are transmitted to TRP 1 and the remaining layers to TRP 2, which can improve channel reliability through diversity gain.
[0258] For FDM, two schemes, 2a and 2b, are supported. Here, scheme 2a transmits a single TB via multi-RB, but transmits RBs belonging to different RB groups to different Tx beams (i.e., QCL RS or TCI state). Scheme 2b transmits the same TB to different RB groups, but transmits RBs belonging to different RB groups to different Tx beams (i.e., QCL RS or TCI state). For TDM, two schemes, 3 and 4, are supported. Here, scheme 4 (i.e., inter-slot TDM) transmits the same TB repeatedly across multiple slots, but transmits slots belonging to different slot groups to different Tx beams (i.e., QCL RS or TCI state). On the other hand, Scheme 3 (i.e., intra-slot TDM) is a method that repeatedly transmits the same TB in multiple OFDM symbol groups, but transmits some OFDM symbol groups and the remaining OFDM symbol groups in different Tx beams (i.e., QCL RS or TCI state).
[0259] Next, we will examine the M-DCI-based M-TRP PDSCH transmission method.
[0260] M-DCI-based MTRP PDSCH transmission is a method in which each TRP schedules and transmits PDSCHs via DCI. That is, TRP 1 transmits PDSCH 1 via DCI 1, and TRP 2 transmits PDSCH 2 via DCI 2. When PDSCH 1 and PDSCH 2 overlap on the same frequency time resource, two PDSCHs are received for the same RE, thereby increasing resource efficiency and transmission capacity. To achieve this, the concept of a CORESET pool, which refers to a group of multiple CORESETs, has been introduced. For example, TRP 1 transmits a PDCCH through a CORESET belonging to CORESET pool 0 and also transmits the PDSCH scheduled by that PDCCH. TRP 2 transmits a PDCCH through a CORESET belonging to CORESET pool 1 and also transmits the PDSCH scheduled by that PDCCH.
[0261] In the case of PUSCH as well, a specific TRP can schedule PUSCH transmissions to the terminal through the CORESETs belonging to each COERSET pool. For example, some PUCCH resources may be scheduled by TRP 1, and the remaining PUCCH resources may be scheduled by TRP 2. The terminal can send independent PUSCH / PUCCH to TRP 1 and 2, respectively.
[0262] Additionally, the terminal may recognize a PUSCH (or PUCCH) scheduled by a DCI received based on a different CORESET (or a CORESET belonging to a different CORESET group) as a PUSCH (or PUCCH) transmitted to a different TRP or as a PUSCH (or PUCCH) of a different TRP. Furthermore, the method for UL transmissions transmitted to different TRPs (e.g., PUSCH / PUCCH) can be applied in the same way to UL transmissions transmitted to different panels belonging to the same TRP.
[0263] Additionally, the CORESET group ID (or, a COERSET pool index having the same meaning) described or mentioned in this disclosure may refer to an index or identification information (e.g., ID) for distinguishing CORESETs for each TRP / panel. Furthermore, a CORESET group may refer to a group or union of CORESETs distinguished by an index or identification information (e.g., ID) or a CORESET group ID for distinguishing CORESETs for each TRP / panel. For example, the CORESET group ID may be specific index information defined within a CORESET configuration. That is, a CORESET group may be set, indicated, or defined by an index defined within the CORESET configuration for each CORESET. And / or, the CORESET group ID may refer to an index, identification information, or indicator for distinguishing or identifying CORESETs configured or associated with each TRP / panel.
[0264] The CORESET group ID described or mentioned in this disclosure may be replaced with a specific index, specific identification information, or specific indicator for distinguishing or identifying between CORESETs set or associated with each TRP / panel. Such information may be set or indicated through higher layer signaling (e.g., RRC signaling, MAC-CE, etc.) and / or physical layer signaling (e.g., DCI). For example, PDCCH detection may be set or indicated for each TRP / panel at the level of the CORESET group, and UCI (e.g., CSI, HARQ-ACK / NACK, SR, etc.) and / or uplink physical channel resources (e.g., PUCCH / PRACH / SRS resources) may be set or indicated to be managed / controlled separately for each TRP / panel at the level of the CORESET group. And / or, HARQ ACK / NACK (process / retransmission) for PDSCH / PUSCH, etc., scheduled for each TRP / panel at the CORESET group level can be managed.
[0265] For example, the upper-level parameter ControlResourceSet IE (information element) is used to set a time / frequency control resource set (CORESET). The CORESET may be associated with the detection / reception of downlink control information. The ControlResourceSet IE may include a CORESET-related ID (e.g., controlResourceSetID), a CORESET pool index for the CORESET (e.g., CORESETPoolIndex), a time / frequency resource setting for the CORESET, and TCI information associated with the CORESET. For example, the index of the CORESET pool (e.g., CORESETPoolIndex) may be set to 0 or 1. In the description above in this disclosure, the CORESET group may correspond to the CORESET pool, and the CORESET group ID may correspond to the CORESET pool index (e.g., CORESETPoolIndex). The aforementioned ControlResourceSet (i.e., CORESET) can be configured through upper-level signaling (e.g., RRC signaling).
[0266] Additionally, regarding M-TRP transmission and reception in the Rel-17 NR standardization, M-TRP PDCCH / PDSCH SFN transmission, S-DCI-based M-TRP PUSCH repeated transmission, and single PUCCH resource-based M-TRP PUCCH repeated transmission are supported. These transmission techniques involve the repeated transmission of the same content (i.e., DCI / UL TB / UCI, etc.) as an improvement to the URLLC target for increased reliability. Here, M-TRP PDCCH repeated transmission is performed based on TDM or FDM, M-TRP PDCCH / PDSCH SFN transmission is performed at the same time / frequency / layer, S-DCI-based M-TRP PUSCH repeated transmission is performed based on TDM, and single PUCCH resource-based M-TRP PUCCH repeated transmission is performed based on TDM.
[0267] First, we will examine the S-DCI-based M-TRP PDCCH iterative transmission method.
[0268] In the NR Rel-17 standardization, for M-TRP PDCCH repetitive transmission, multiple CORESETs with different TCI states (i.e., different QCL RS) are configured for the terminal, and multiple SS (Search Space) sets are configured, each connected to a corresponding CORESET. The base station can indicate / configure to the terminal that the SS set connected to one CORESET is linked to the SS set connected to another CORESET for repetitive transmission. Through this, the terminal can know that the PDCCH candidates of the corresponding SS set are being repetitively transmitted.
[0269] For example, two CORESETs, CORESET 0 and CORESET 1, are configured for the terminal, and CORESET 0 and CORESET 1 are connected to SS set 0 and SS set 1, respectively, and SS set 0 and SS set 1 may be linked. The terminal can recognize that the same DCI is repeatedly transmitted in the PDCCH candidate of SS set 0 and the PDCCH candidate of SS set 1, and can recognize that a specific PDCCH candidate of SS set 0 and a specific PDCCH candidate of SS set 1 are a pair configured to repeatedly transmit the same DCI based on a specific rule. These two PDCCH candidates are referred to as linked PDCCH candidates, and the terminal can successfully decode the corresponding DCI if it appropriately receives either of the two PDCCH candidates. However, when the terminal receives a PDCCH candidate of SS set 0, it may use the QCL RS of the TCI state of COERSET 0 connected to SS set 0 (i.e., the DL beam), and when it receives a PDCCH candidate of SS set 1, it may use the QCL RS of the TCI state of COERSET 1 connected to SS set 1 (i.e., the DL beam). Accordingly, the terminal receives the associated PDCCH candidates using different beams.
[0270] Next, we will examine the M-TRP SFN PDCCH / PDSCH transmission method.
[0271] As a form of M-TRP PDCCH repetitive transmission, multiple TRPs can repeatedly transmit the same DCI through the same time / frequency / DMRS port, and this transmission method can be referred to as SFN PDCCH transmission. However, for SFN PDCCH transmission, instead of configuring multiple CORESETs with different TCI states, the base station configures multiple TCI states in a single CORESET. When a terminal receives a PDCCH candidate through an SS set connected to that single CORESET, it can utilize all of the multiple TCI states to perform channel estimation of the PDCCH DMRS and attempt decoding.
[0272] Additionally, when the above-described M-TRP PDSCH is repeatedly transmitted, the two TRPs repeatedly transmit the corresponding channel to different resources. However, if the resources used by the two TRPs are identical, that is, if the same channel is repeatedly transmitted through the same frequency / time / layer (i.e., DMRS port), the reliability of the channel can be improved. In this case, since the resources of the repeatedly transmitted same channel are not distinguished, they are combined and received during transmission (i.e., air), so from the perspective of the receiving end (e.g., terminal), it may be recognized as a single channel (e.g., composite channel). For SFN PDSCH transmission, two DL TCI states for PDSCH DMRS reception may be configured for the terminal.
[0273] Next, we examine the S-DCI-based M-TRP PUSCH iterative transmission method.
[0274] In the NR Rel-17 standardization, for S-DCI-based M-TRP PUSCH transmission, the base station sets two SRS sets for the terminal, each set used to indicate the UL Tx port and UL beam / QCL information for TRP 1 and TRP 2, respectively. Additionally, the base station uses two SRI fields included in a single DCI to indicate SRS resources for each SRS resource set and can indicate up to two PC parameter sets. For example, the first SRI field can indicate the SRS resources and PC parameter sets defined in SRS resource set 0, and the second SRI field can indicate the SRS resources and PC parameter sets defined in SRS resource set 1. The terminal can receive the UL Tx port, PC parameter set, and UL beam / QCL information for TRP 1 through the first SRI field, and thereby the terminal performs PUSCH transmission at the TO corresponding to SRS resource set 0. Similarly, the terminal can be instructed by the UL Tx port, PC parameter set, and UL beam / QCL information for TRP 2 through the second SRI field, and thereby the terminal performs a PUSCH transmission at the TO corresponding to SRS resource set 1.
[0275] Next, we examine the single PUCCH resource-based M-TRP PUCCH iterative transmission method.
[0276] In the NR Rel-17 standardization, for M-TRP PUCCH transmission based on a single PUCCH resource, a base station may enable / configure two spatial relation infos to the terminal on the single PUCCH resource (or enable / configure two PC parameter sets if it is FR1). When a UL UCI is transmitted through the said PUCCH resource, each spatial relation info is used to instruct the terminal on the spatial relation info for TRP 1 and TRP 2, respectively. For example, through the value indicated by the first spatial relation info, the terminal is instructed on the Tx beam / PC parameter(s) for TRP 1, and the terminal uses this information to perform PUCCH transmission at the TO corresponding to TRP 1. Similarly, through the value indicated by the second spatial relation info, the terminal is instructed on the Tx beam / PC parameter(s) for TRP 2, and the terminal uses this information to perform PUCCH transmission at the TO corresponding to TRP 2.
[0277] In addition, for repeated M-TRP PUCCH transmission, the configuration method has been improved so that two spatial relation infos can be configured in the PUCCH resource. That is, if power control (PC) parameters such as PLRS, Alpha, P0, and Closed loop index are configured in each spatial relation info, a spatial relation RS can be configured. Consequently, PC information and spatial relation RS information corresponding to two TRPs can be configured through the two spatial relation infos. Through this, the terminal transmits a UCI (i.e., CSI, ACK / NACK, SR, etc.) PUCCH using the first spatial relation info in the first TO, and transmits the same UCI PUCCH using the second spatial relation info in the second TO. In the present disclosure, a PUCCH resource with two spatial relation infos configured is referred to as an M-TRP PUCCH resource, and a PUCCH resource with one spatial relation info configured is referred to as an S-TRP PUCCH resource.
[0278] In addition, in an NR wireless communication system, S-DCI-based multi-TB PUSCH / PDSCH scheduling may be considered. For example, in the ultra-high frequency band (e.g., beyond 5.26 GHz, FR2 band) of an NR wireless communication system (e.g., a Rel-17-based NR system), a method in which a single DCI simultaneously schedules multiple PUSCHs / PDSCHs may be supported.
[0279] As a specific example, multiple time resources (e.g., TDRA, TO (Transmission Occasion)) can be indicated simultaneously through the time resource allocation field (e.g., TDRA field) of the DCI scheduling PUSCH. In this case, different TBs can be transmitted via PUSCH for each TO. The values of the frequency resource allocation field (e.g., FDRA field), the Modulation and Coding Scheme (MCS) field, the Transmitted Precoding Matrix Indicator (TPMI) field, and / or the SRS Resource Indicator (SRI) field of the corresponding DCI can be applied commonly to multiple scheduled TBs. Additionally, the New Data Indicator (NDI) and Redundancy Version (RV) for each TB are indicated individually through the corresponding DCI, and while a single HARQ number is indicated, it can increase sequentially in the order of TOs based on the initial TO.
[0280] STxMP (simultaneous transmission for multiple panels)
[0281] In addition, regarding NR wireless communication systems, a method in which a terminal simultaneously transmits multiple channels / RS of the same type or multiple channels / RS of different types may be considered.
[0282] In the case of existing terminals, the operation of transmitting multiple channels / RSs at a single time was limited. For example, a terminal can simultaneously transmit multiple SRS resources from different sets of SRS resources for UL beam management, but cannot simultaneously transmit multiple PUSCHs. In contrast, future advanced terminals may be considered to relax the above limitations and transmit multiple channels / RSs simultaneously using multiple transmission panels. Such a terminal may be referred to as an STxMP (simultaneous transmission across multi-panel) terminal.
[0283] For example, a method may be applied in which two PUSCHs corresponding to two UL TBs (i.e., a first PUSCH and a second PUSCH) are scheduled in the same RE (resource element), and a first spatial information RS and a first PC (power control) parameter set are set for the first PUSCH, and a second spatial information RS and a second PC parameter set are set for the second PUSCH. That is, a first UL TCI state may be set for the first PUSCH, and a second UL TCI state may be set for the second PUSCH. In this case, the terminal may transmit the first PUSCH using a first Tx spatial filter (e.g., a first panel) corresponding to the first UL TCI state, and transmit the second PUSCH using a second Tx spatial filter (e.g., a second panel) corresponding to the second UL TCI state.
[0284] In this regard, when a base station schedules a PUSCH via DCI, the base station may instruct the terminal on which of the following to apply as the PUSCH transmission method: STxMP, a single panel-based method, or an M-TRP-based PUSCH iterative transmission method. Here, the STxMP method is possible only if the terminal supports STxMP capability, and the STxMP mode must be enabled in advance for the terminal through RRC signaling, etc. To this end, the existing SRS resource set indication field may be redefined, or a new DCI field may be introduced.
[0285] Additionally, regarding the aforementioned STxMP transmission method, two methods can be considered: the SFN (single frequency network) method and the SDM (spatial division multiplexing) method.
[0286] Specifically, the SFN method is a method of transmitting the same channel as transmitted from one panel to another panel. In this case, since the UL channels of each panel may differ, UL transmission can be performed by using different precoders, different transmission powers, and different transmission beams (e.g., spatial relationship RS indicated by UL TCI status) for each panel, taking this into consideration.
[0287] The SDM method is a method applicable to transmissions based on ranks greater than or equal to 2, in which some layers of a multi-layer system are transmitted from one panel and the remaining layers are transmitted from another panel. For example, in the case of an SDM method for 2-layer transmission, the first layer may be transmitted from the first panel and the second layer may be transmitted from the second panel. In this case, since the UL channels of each panel may differ, UL transmission may be performed by taking this into account and using different precoders, different transmission powers, and different transmission beams (e.g., spatial relationship RS indicated by the UL TCI status) for each panel.
[0288] The panels described in this disclosure may be replaced with other resources / terms corresponding to the panels.
[0289] For example, different panels may be mapped to different SRS resource sets or SRS resources. As a specific example, the first panel may be mapped to SRS resource set 0, and the second panel may be mapped to SRS resource set 1. In this case, the SRS resource(s) belonging to SRS resource set 0 may be associated with the (transmitting) antenna port of the first panel, and the SRS resource(s) belonging to SRS resource set 1 may be associated with the (transmitting) antenna port of the second panel.
[0290] In this regard, other resources / terms corresponding to panels are used. For example, different panels may be mapped to different sets of SRS resources or SRS resources. For example, the first panel is mapped to SRS resource set 0 and the second panel is mapped to SRS resource set 1, and the SRS resources of SRS resource set 0 may refer to the transmitting antenna port of the first panel and the SRS resources of SRS resource set 1 may refer to the transmitting antenna port of the second panel.
[0291] DCI scheduling methods for STxMP PUSCH can be broadly classified into two types. S-DCI-based STxMP is a method in which a single DCI performs PUSCH scheduling for STxMP transmission, and transmission can be performed using a pre-configured technique (e.g., SFN or SDM) through RRC settings. M-DCI-based STxMP is a method in which different DCIs schedule the PUSCH transmitted by each panel. That is, assuming there are two panels, the first DCI schedules PUSCH 1 transmitted by Panel 1, and the second DCI schedules PUSCH 2 transmitted by Panel 2. In this case, the first DCI is transmitted through the CORESET corresponding to CORESET pool index = 0, and the second DCI can be transmitted through the CORESET corresponding to CORESET pool index = 1. PUSCH 1 can be transmitted using the port of the SRS resource of SRS resource set 0, and PUSCH 2 can be transmitted using the port of the SRS resource of SRS resource set 1.
[0292] In the case of STxMP PUCCH, if a single PUCCH resource is configured to have two UL TCI states or two Joint TCI states applied, the PUCCH resource can be transmitted via SFN STxMP. Otherwise, if a single UL TCI state or one Joint TCI state is configured to apply, the PUCCH resource can be transmitted via a single panel.
[0293] In this regard, UL panels may be represented in a one-to-one correspondence with a specific set of SRS resources, UL TCI states, joint TCI states, spatial relation RS, TAG, or panel ID. For example, if SRS resource sets 0 and 1 are configured, a PUSCH transmission using SRS resource set 0 is transmitted through panel 0, and a PUSCH transmission using SRS resource set 1 can be transmitted through panel 1. Similarly, if two UL TCI states are configured, a PUSCH transmission with the first UL TCI state is transmitted through panel 0, and a PUSCH transmission with the second UL TCI state is transmitted through panel 1. In a similar manner, if two joint TCI states, spatial relation RS, TAG, or panel ID, etc. are configured, they may be mapped to and used with panel 0 and panel 1, respectively.
[0294] CSI report initiated by the terminal
[0295] In wireless communication systems, uplink control information at Layer 1 (e.g., the physical layer) has the advantage of having a smaller transmission delay compared to control information at higher layers. For instance, in order for a terminal to transmit information to a base station via MAC-CE or RRC messages, the terminal's SR (scheduling request) procedure and the base station's PUSCH allocation procedure (based on the SR) may be required, which may result in delays and overhead. Furthermore, generally, the higher the layer of information, the longer the time required to decode the information (e.g., decoding time, processing time). Additionally, to transmit Layer 1 UL control information, UL physical channel resources (e.g., PUCCH, PUSCH) must be configured or allocated to the corresponding terminal. In other words, from the perspective of the network (NW) (or base station), as the number of terminals (UE) increases, the amount of UL resources that must be allocated to each terminal increases, which can lead to greater overhead regarding the overall utilization of UL resources.
[0296] Therefore, in a wireless communication system, information that must be transmitted relatively urgently for the operation of the physical layer (e.g., SR (for PUSCH allocation), HARQ-ACK (for retransmission), CSI (for scheduling, MCS, and precoder determination), and beam information (for digital / analog beam determination)) is transmitted as physical layer uplink control information (UCI). Among the information in such examples, excluding SR, the network (or base station) determines / controls the timing of information reporting by the terminal.
[0297] However, network-initiated / triggered reporting has a limitation in that terminals must be configured / instructed to transmit UCIs frequently in environments where the wireless channel is likely to change rapidly. In other words, in such environments, the overhead of UL resources for UCI reporting and the associated RS overhead for DL measurements increase, and problems may arise where the terminal's power consumption increases due to frequent UL transmission. Additionally, as the number of terminals within the cell / TRP coverage increases, the overhead for UL resources increases because UL resources must be allocated to each terminal.
[0298] To overcome the limitations of reporting initiated / triggered by the network as described above, reporting methods initiated / triggered by the terminal and / or event-based / triggered reporting methods may be considered. In the case of reporting methods initiated / triggered by the terminal and / or event-based / triggered reporting methods, whether to report and / or the timing of the report can be determined by the terminal. That is, by having the terminal perform the relevant report (e.g., UCI reporting) only when necessary (e.g., when a specific event occurs), UL resource overhead and terminal power consumption can be reduced. Additionally, since information is reported based on a lower layer (e.g., Layer 1), there is a technical effect of enabling rapid reporting to the network.
[0299] Based on the aforementioned objectives, a method for beam reporting initiated / triggered by a terminal is being considered. Furthermore, in next-generation communication systems, for the efficient operation of uplink resources, transmission methods initiated / triggered by terminals and / or event-based transmission methods may be extended and applied to the transmission of control information, transmission blocks, user-plane data, etc., which were previously transmitted via existing UCI (uplink control information) and / or MAC-CE.
[0300] In this regard, there are representative reporting methods, such as scheduling request (SR) and beam failure recovery (BFR), as event-based or terminal-initiated / triggered reporting information. SR is a method of reporting whether a PUSCH allocation is required for UL-SCH transmission, and BFR is a method of reporting whether a BF has occurred and information related to a new beam. Such information may be transmitted in an explicit or implicit manner (e.g., by transmitting a new beam index as PRACH resource selection information) and may be transmitted at once or in installments through one or multiple (e.g., two) UL resources. For example, such information may be transmitted via BFRQ in PUCCH and beam information via MAC-CE on PUSCH. In this disclosure, information transmitted to the network through event-based and / or terminal-initiated / triggered transmission methods as described above (e.g., SR, BFRQ, new beam information, etc.) is referred to as "event information" for the convenience of explanation.
[0301] The CSI reporting method supported by existing wireless communication systems is a method initiated / triggered by the network. As communication systems evolve, high-precision CSI reporting is supported, but because the amount of CSI information that must be sent at once increases due to high precision / granularity, the amount of UL resources (e.g., PUCCH, PUSCH, etc.) required for CSI reporting increases.
[0302] For example, a method of performing event-based CSI reporting via UCI or MAC-CE may be considered. When reporting via UCI or MAC-CE, if a UL resource capable of sending the information (e.g., available UL SCH) is not allocated / configured, a request for PUSCH / PUCCH allocation to the base station may be made through a procedure such as SR. In this disclosure, for convenience of explanation, a UL resource requesting a PUSCH / PUCCH allocation for CSI reporting corresponding to an event may be referred to as the first resource, and a UL resource performing the CSI reporting may be referred to as the second resource. A terminal may report whether an event has occurred to the base station via the first resource. Subsequently, if the base station wishes to receive a CSI report regarding the event, it may trigger an aperiodic (AP) CSI report for the CSI via DCI and schedule the second resource. The terminal may report the CSI from the UL resource scheduled via DCI (e.g., the second resource).
[0303] As another example, a base station may pre-configure / assign a UL resource (e.g., PUCCH / PUSCH) for the event-based reporting to a terminal. When performing UCI / MAC-CE-based CSI reporting through the UL resource, the base station may always need to monitor this because the terminal can perform CSI reporting through the UL resource at any time. To reduce such overhead, the terminal may be configured to notify the base station in advance that it will perform transmission from the UL resource through a separate UL resource (e.g., short PUCCH, SR PUCCH, PRACH) (which has small overhead). In this disclosure, for convenience of explanation, a separate UL resource supporting a small payload size may be referred to as the first resource, and a UL resource performing CSI reporting may be referred to as the second resource. For example, a PUCCH or PRACH resource capable of transmitting information of about 1 to several bits may be considered as a first resource, and a PUCCH or PUSCH resource capable of transmitting information of tens of bits or more (e.g., a resource for a set grant or semi-continuous CSI) may be considered as a second resource. As mentioned above, the first resource is not always required, and CSI reporting using only the second resource may be possible when the base station is not burdened with UL resource monitoring and / or the amount of the second resource is not large.
[0304] The report quantity of CSI based on the aforementioned method may include not only traditional channel state information such as CRI / RI / PMI / CQI / LI, but also beam information such as CSI-RS index and / or L1-RSRP, CSI-RS index and / or L1-SINR, SSB index and / or L1-RSRP, SSB index and / or L1-SINR, etc. Additionally, the report quantity may include explicit feedback information regarding the measured channel / interference. For example, this may be a value obtained by quantizing the eigenvector and eigenvalue of the measured channel, or a value obtained by appropriately decomposing the measured channel to quantize only the meaningful channel information. Furthermore, this may be a value obtained by compressing and quantizing the channel information to reduce payload.
[0305] Additionally, in terminal-driven or event-based beam reporting, matters concerning beam quality metrics, event definitions, and thresholds may be considered in relation to event detection for triggering beam reporting. For example, trigger events for beam reporting may be defined to include, but are not limited to, the following types.
[0306] Specifically, the trigger event may include at least one of the following.
[0307] - Event 1 may include cases where the quality of the beam currently in use deteriorates below a preset threshold.
[0308] - Event 2 may include cases where the quality of at least one of the new beams (e.g., L1-RSRP) becomes better than the quality of the current beam by a threshold amount.
[0309] - Event 3 may include cases where the quality of the new beam becomes better than a preset threshold.
[0310] - Event 4 may include a case where the quality of the current beam deteriorates below a first threshold, and at the same time, the quality of at least one of the new beams becomes better than a second threshold.
[0311] - Event 7 may mean that the quality of at least one of the new beams (e.g., L1-RSRP) becomes better than the reference signal having the Qth best quality derived from the activated TCI state by a threshold amount.
[0312] The corresponding Q value can be set through wireless resource control (RRC) and can be determined based on the terminal's capability information (UE capability signaling). According to one embodiment, the terminal may indicate only a single candidate Q value or may not support Event 7. Additionally, additionally supported events such as Event 1 and Event 7 may be implemented by reusing the same design principles as Event 2 unless there is a special agreement, and these events may be configured to have a relatively lower priority compared to Event 2.
[0313] It is evident that various additional event conditions can be defined besides this.
[0314] In addition, when at least one of the aforementioned events is satisfied, the terminal may perform a beam report according to a procedure corresponding to the event, and the specific operation method related thereto may be implemented in various ways depending on the embodiment.
[0315] Terminal-driven or event-based predictive CSI / BEAM reporting
[0316] The present disclosure proposes a method for reporting on predicted CSI and / or predicted beams based on a terminal-led or event-based beam reporting method (hereinafter referred to as terminal-initiated (UE-initiated, UEI) reporting for convenience of explanation).
[0317] In this regard, the terminal start report may be based on two modes as illustrated in FIG. 16.
[0318] FIG. 16 is an example for explaining the operation mode of a terminal start report that can be applied to the present disclosure.
[0319] FIG. 16(a) illustrates an example of a beam reporting operation according to Mode A. In one embodiment, the terminal can perform beam measurements based on a measurement value for a reference signal (RS) set by the base station, such as L1-RSRP. The terminal can compare the measurement value of the new beam with the measurement value of the current beam, and if the measurement value of the new beam is greater than the measurement value of the current beam by more than a threshold set by the base station, it can determine that Event 2 has occurred / triggered. Additionally, if other events other than Event 2 are defined, whether an event occurs / triggered can be determined according to the definition of the event.
[0320] When an event occurs or is triggered in this manner, the terminal can report whether the event has occurred through a subsequently obtained PUCCH, for example, a pre-configured periodic PUCCH. As an example, the terminal can report whether the event has occurred using 1-bit information; for instance, a value of 1 indicates that the event has occurred, and a value of 0 indicates that the event has not occurred. The base station can receive the event occurrence status through the corresponding PUCCH, and if the event is reported, it can schedule a PUSCH to perform beam reporting for the event using DCI. Subsequently, the terminal can perform beam reporting through the scheduled PUSCH.
[0321] FIG. 16(b) illustrates an example of a beam reporting operation according to mode B. In one embodiment, the terminal can compare the measurement value of a new beam with the measurement value of a current beam based on a measurement reference signal (RS) set by the base station, e.g., L1-RSRP. If the measurement value of the new beam is greater than the measurement value of the current beam by more than a threshold value set by the base station, it may be determined that Event 2 has occurred / triggered, and if other events other than Event 2 are defined, the occurrence / triggering of the event may be determined according to the event definition.
[0322] When an event occurs / triggered in this manner, the terminal may report whether the event occurred as a 1-bit value through a subsequently secured physical uplink control channel, e.g., a pre-configured periodic PUCCH. For instance, a value of 1 may indicate that the event occurred, and a value of 0 may indicate that the event did not occur. Subsequently, the terminal may perform beam reporting using the most recent PUCCH set after x symbols from the time of the PUCCH report, among the pre-configured PUCCHs (e.g., a configured grant-based PUCCH). Conversely, if the terminal reports via PUCCH that the event did not occur, it may not perform beam reporting via PUCCH.
[0323] Recently, in wireless communication systems, technology is being introduced in which terminals predict channel conditions at future points in time and report them to base stations. For example, in Rel-18 MIMO, a function may be supported in which a terminal performs CSI prediction and reports the predicted CSI. Specifically, the terminal can predict the downlink channel after the time of CSI reporting, calculate the CSI based on the predicted channel, and report it to the base station. Furthermore, in Rel-19, technology is being discussed in which terminals use AI / ML to predict beam quality values at future points in time, such as L1-RSRP, and report the predicted values after the time of beam reporting to the base station.
[0324] However, since the above operations are generally performed based on instructions from the base station, there is a problem in that prediction-based CSI or beam reporting may be performed even when the terminal's prediction accuracy is low. For example, the terminal could be configured to report prediction accuracy along with the data, but in this case, additional uplink reporting information is required, which may increase uplink overhead. Furthermore, even if the predicted value at a future point in time does not differ significantly from the currently measured value, the currently measured value and the predicted value for future points in time (e.g., multiple future points in time) may be reported together; thus, uplink overhead may increase due to unnecessary uplink reporting.
[0325] Accordingly, to solve the aforementioned problem, the present disclosure proposes a method in which a terminal determines, based on event evaluation, whether to perform prediction-based CSI or beam reporting, and selects / determines and reports either prediction-based CSI or beam reporting or conventional CSI or beam reporting based on the result. Through this, the terminal can selectively perform the reporting method according to the validity or necessity of the prediction, and can reduce uplink overhead by reducing unnecessary reporting.
[0326] In the following, various embodiments for prediction-based CSI or beam reporting initiated by a terminal are proposed. Specifically, a method for defining an event related to the report (hereinafter Embodiment 1), a specific prediction-based CSI or beam reporting operation based on the event (hereinafter Embodiment 2), a method for improving the reliability of the prediction-based CSI (hereinafter Embodiment 3), and a method for determining the payload size based on whether the event occurs (hereinafter Embodiment 4) are described.
[0327] The embodiments described below are distinguished merely for convenience and clarity of explanation, and it is obvious that the embodiments of the present disclosure may be combined or combined with one another, or that some components may be substituted and applied.
[0328] Example 1
[0329] This embodiment relates to a method for newly defining events related to prediction-based CSI or beam reporting initiated by a terminal.
[0330] Specifically, the present disclosure may define an event-based operation for a terminal to determine whether to perform a prediction-based beam report or a prediction-based CSI report. For example, a new event for a UEI-based prediction beam or CSI report, such as Event-P, may be defined.
[0331] In this regard, the terminal may evaluate one or more event conditions related to a prediction time window. Based on the evaluation results of the event conditions, the terminal may determine whether to perform a prediction-based beam report or a prediction-based CSI report. Here, information regarding the prediction time window may be set by the base station together with the configuration for the report, or may be set through separate signaling. Similarly, information regarding multiple time points (e.g., multiple time instances) included in the prediction time window may also be set by the base station together with the configuration for the report, or may be set through separate signaling.
[0332] For example, if the corresponding event condition is satisfied, the terminal may perform a report including prediction-based beams or CSIs corresponding to multiple future time points. That is, the terminal may predict beam information or CSI information for one or more future time points within a prediction time interval and report the predicted beam information or CSI information to the base station.
[0333] On the other hand, if the corresponding event conditions are not satisfied, the terminal may perform conventional beam reporting or CSI reporting instead of prediction-based reporting. For example, the terminal may transmit beam information or CSI information calculated based on channel measurements at the current time point to the base station in the form of a report for a single time point without prediction.
[0334] In one embodiment, the event condition may include a condition related to the time-domain change characteristics of a beam or channel within a predicted time interval. For example, the terminal may calculate the amount of time-domain change of a beam or CSI within a predicted time interval and determine that Event-P has occurred if the amount of change is greater than a first threshold (hereinafter, for convenience of explanation, the case / condition is referred to as the first condition). In such a case, since the beam or channel state may change rapidly over time, existing beam reports or CSI reports based on a single point in time without prediction may quickly become outdated information. Therefore, the terminal may perform prediction-based beam or CSI reporting for a future point in time.
[0335] As another example, the event condition may include a case where the amount of time-domain change of the beam or CSI within the prediction time interval is smaller than a second threshold (hereinafter, for convenience of explanation, such case / condition is referred to as the second condition). In such a case, the beam or channel state may be determined to have relatively static characteristics over time. Therefore, since existing beam reports or CSI reports based on current channel measurements can be effectively used at future points in time within the prediction time interval, the terminal may not perform prediction-based beam or CSI reporting. In this regard, the terminal may additionally report information to the base station indicating that the existing beam reports or CSI reports can be effectively used even within the prediction time interval.
[0336] As another example, the event condition may include conditions related to the reliability or accuracy of the predicted beam or CSI. For example, the terminal may calculate the reliability or accuracy of the predicted beam or CSI and determine that Event-P has occurred if the reliability or accuracy is greater than a third threshold (hereinafter, for convenience of explanation, such case / condition is referred to as the third condition). In such a case, the terminal may perform a prediction-based beam or CSI report by determining that the reliability of the prediction result is sufficiently high. On the other hand, if the prediction accuracy is lower than the third threshold, the terminal may perform a conventional beam report or CSI report instead of a prediction-based report.
[0337] The event condition may include one or more of the aforementioned first, second, and third conditions. For example, the terminal may determine whether an event occurs based on one of the above conditions, or may determine whether an event occurs by combining multiple conditions.
[0338] For example, since the uncertainty of the prediction result may increase when the time domain change of the beam or CSI is large within the prediction time interval, the terminal may be configured to determine that Event-P has occurred only when the first and third conditions are simultaneously satisfied. That is, prediction-based beam or CSI reporting may be performed only when the time change of the channel or beam is large and the prediction accuracy is sufficiently high.
[0339] In this way, by configuring the terminal to determine whether to perform prediction-based reporting based on event evaluation results, prediction-based reporting can be performed only when the validity of the prediction result is high. Additionally, uplink reporting overhead can be reduced by minimizing unnecessary prediction-based reporting.
[0340] Additionally, the aforementioned first threshold, second threshold, and third threshold may be set to different values as they can be used for different purposes. For example, the first and second thresholds may be used as criteria for determining the time-domain change characteristics of the beam or channel state, and the third threshold may be used as a criterion for determining the reliability or accuracy of the prediction result.
[0341] The reliability or accuracy of the predicted beam can be calculated based on the probability value for the predicted beam. For example, the terminal determines the predicted beam for a specific time point as the first beam and can calculate the probability value that the first beam will actually be the optimal beam at that time point.
[0342] Reliability or accuracy can be calculated based on the probability values of the prediction beam calculated for each time point within the prediction time interval. For example, if the average or minimum value of the probability values for each time point is greater than or equal to a third threshold, it may be determined that the third condition is satisfied. Additionally, even when using arbitrary reliability or accuracy values instead of probability values, the corresponding condition can be determined in the same manner using the average or minimum value of the values for multiple time points.
[0343] Additionally or alternatively, if the terminal predicts beams using an AI / ML-based model, the terminal may use specific performance metrics to monitor the performance of said model. For example, the terminal may directly use said performance metric as a value representing prediction accuracy, or it may calculate a separate accuracy value using said performance metric.
[0344] Additionally or alternatively, the reliability or accuracy of the prediction results may be determined based on statistical characteristics between the predicted value and actual measurements from the past or up to the present. For example, if the mean, variance, or other statistical characteristics of the predicted value and past measurements are similar to each other, the reliability of the prediction results may be considered high.
[0345] Meanwhile, the first and / or second conditions described above are determined by calculating the time-domain change amount for the predicted CSI within the prediction time interval. Alternatively, the said time-domain change amount may be calculated based on the CSI measured within the actual measurement window instead of the prediction time interval. For example, if the time-domain change characteristics of the actual measured CSI values are large, there is a high probability that the channel change will be large in subsequent time intervals; conversely, if the time-domain change characteristics of the actual measured CSI values are small, there is a high probability that the channel change will be small in subsequent time intervals. Therefore, event conditions can be defined based on these characteristics.
[0346] In relation to the first condition and / or the second condition, the time-domain variation may be calculated based on predicted beam or CSI measurements for multiple time points spaced at regular time intervals within the predicted time interval. For example, the predicted values may include one or more of the following: predicted L1-RSRP, predicted L1-SINR, predicted L1-RSRQ, predicted beam measurement quality, predicted rank indicator (RI), predicted precoding matrix indicator (PMI), predicted channel quality indicator (CQI), or predicted SINR. In this case, the time-domain variation may be calculated using the mean, variance, or standard deviation of the values. Additionally, in the case of the predicted PMI, the time-domain variation may be calculated using the correlation values between the corresponding preprocessing matrices. For example, the time-domain variation may be calculated using the mean, variance, or standard deviation of the correlation values between the preprocessing matrices corresponding to the predicted PMI at multiple time points.
[0347] Additionally or alternatively, with respect to the first condition and / or the second condition, the time-domain variation may be calculated based on the difference between the predicted beam or CSI value and the actual measured beam or CSI value. For example, the difference between the predicted value and the measured value for each time point may be calculated, and the average of said difference values may be defined as the time-domain variation.
[0348] Additionally or alternatively, similarity or error-based metrics may be used to define the amount of time-domain variation in relation to the first condition and / or the second condition. For example, metrics such as Squared Generalized Cosine Similarity (SGCS) or Normalized Mean Square Error (NMSE) may be used. As an example, the SGCS or NMSE values between the existing CSI or beam value calculated based on the latest measurement and the predicted CSI or beam value may be calculated, and the amount of time-domain variation may be defined using the mean, variance, or standard deviation of said values.
[0349] Additionally or alternatively, the terminal may adjust the time interval or the number of time points of the prediction information reported to the base station based on the aforementioned time domain variation characteristics. For example, if the time variation characteristics of the beam or CSI are large, the terminal may reduce the time interval between multiple future time points or increase the number of reported time points. Conversely, if the time variation characteristics are small, the terminal may increase the time interval between time points or decrease the number of reported time points. Through this, the terminal can improve reporting efficiency while adaptively responding to channel variation characteristics.
[0350] Example 2
[0351] This embodiment relates to a beam reporting or CSI reporting operation of a terminal based on the event-P proposed in Embodiment 1.
[0352] In the following, we will distinguish between cases where periodic or semi-persistent CSI reporting is configured for the terminal and cases where aperioditic CSI reporting is configured.
[0353] FIG. 17 illustrates an example of an operation in which a terminal according to an embodiment of the present disclosure determines a predicted beam or predicted CSI report and performs a report. The operation illustrated in FIG. 17 assumes that the terminal is set to a periodic beam report or CSI report, or a semi-continuous beam report or CSI report.
[0354] Referring to FIG. 17, a base station may set a beam report or CSI report to a terminal that operates at period P. For example, the base station may set a measurement RS resource, such as CSI-RS, to the terminal, and the terminal may use said measurement resource to calculate a beam-related value or a CSI value for a beam report or CSI report.
[0355] The terminal can predict not only the beam or CSI value at the current time point, but also the channel at a time point after the currently received measurement resource or the most recently received measurement resource. Based on the predicted channel, the terminal can calculate the beam value or CSI value for one or more future time points. Additionally, the terminal can use these calculated values to evaluate whether the Event-P condition is satisfied.
[0356] In this case, future time points may include multiple time points spaced at regular intervals within a prediction time interval (e.g., a prediction window). The start time of the prediction time interval may be determined based on one or more of the following. For example, the start time may be determined based on the time of reception of the currently received measurement resource, the time of reception of the most recently received measurement resource, the CSI reference resource slot, or the time at which a beam report or CSI report is performed or thereafter.
[0357] Additionally, the last point in time of the prediction time interval can be determined by adding a pre-set interval length (e.g., window size) at the start time. For example, this interval length may be a value set by the base station to the terminal, or it may be a value determined by the terminal and reported to the base station. Furthermore, the number of points in time included within the prediction time interval may also be set by the base station or determined and reported by the terminal.
[0358] Additionally, if the Event-P condition is not satisfied, the terminal may report beam or CSI values for which no prediction was performed, in the same manner as the existing method. For example, the terminal may transmit a beam or CSI value at a single point in time, calculated based on the current channel measurement, to the base station.
[0359] On the other hand, if the Event-P condition is satisfied, the terminal can perform a report including a prediction beam or CSI value for one or more future points in time within the prediction time interval.
[0360] For example, in FIG. 17, the terminal may determine that the event condition is satisfied in the CSI report performed at time point T, and accordingly, may report the predicted beam or CSI value within the predicted time interval. In this case, the predicted time interval may include time points T, T+P, and T+2P, and the terminal may report the predicted beam or CSI value corresponding to the plurality of time points to the base station. In this way, if information for the plurality of time points is reported in advance, the terminal may omit the periodic beam or CSI report performed at time points T+P and T+2P.
[0361] If the event condition is not satisfied in the CSI report performed at the subsequent time point T+3P, the terminal may report a beam or CSI value for which no prediction was performed, in the same way as the existing method.
[0362] When the event condition corresponds to the first condition described in Example 1, a significant change in the channel may occur within the prediction time interval, so beam or CSI values for multiple time points within the prediction time interval may all be reported.
[0363] On the other hand, if the event condition corresponds to the second condition described in Example 1, the channel change within the prediction time interval may be relatively small, so only the beam or CSI value for the reference time point within the prediction time interval may be reported. Additionally, the terminal may additionally report information indicating that an event has occurred. For example, the terminal may also report 1-bit information indicating whether an event has occurred.
[0364] For example, the reference point may be set to one of the first, last, or intermediate points of the prediction time interval. Additionally, or alternatively, if the terminal can adjust the prediction time interval itself, the terminal may additionally report information regarding the prediction time interval satisfying the second condition.
[0365] FIG. 18 illustrates another example of an operation in which a terminal according to an embodiment of the present disclosure determines a predicted beam or predicted CSI report and performs the report. The operation illustrated in FIG. 18 assumes that a non-periodic beam report or CSI report is set for the terminal.
[0366] Referring to FIG. 18, the base station can use DCI to instruct the terminal to report a non-periodic beam or CSI. For example, the base station can trigger a non-periodic CSI report to the terminal via DCI.
[0367] The terminal can evaluate the event condition in response to the corresponding report instruction. If the event condition is not satisfied, for example, when time T0 in FIG. 18 is present, the terminal can report a beam or CSI value for which no prediction was performed, in the same manner as in the conventional method.
[0368] On the other hand, when the event condition is satisfied, for example, when time T of FIG. 18, the terminal can perform a report including the predicted beam or CSI value within the predicted time interval.
[0369] The setting of the prediction time interval, the method for evaluating event conditions, and the method for determining the type or content of the beam or CSI information reported according to the event conditions can be applied in the same or similar way as the periodic / semi-continuous beam reporting or CSI reporting-based operation described in FIG. 17.
[0370] Therefore, even in non-periodic CSI reporting situations, the terminal can select and perform either prediction-based reporting or conventional reporting based on the event condition evaluation results.
[0371] Example 3
[0372] This embodiment relates to a method for ensuring the reliability of a predicted CSI report or a predicted beam report.
[0373] As described in FIGS. 17 and 18, a prediction-based beam report or a prediction-based CSI report performed at a specific time point (e.g., time point T) may contain a relatively large amount of information compared to reports at other time points. For example, since the terminal may report beam information or CSI information for multiple time points within the prediction time interval together, the amount of reported information may increase compared to a conventional report for a single time point.
[0374] Therefore, to improve the reliability of prediction-based CSI reporting, one or more of the following methods may be applied.
[0375] As one method, the terminal may repeatedly transmit the prediction-based CSI report to improve the reliability of the prediction-based CSI report. For example, the terminal may transmit the prediction-based CSI report repeatedly N times, and the number of repetitions N can be set by the base station to the terminal.
[0376] In one embodiment, as shown in FIG. 17, when based on periodic / non-periodic CSI reporting, the terminal can repeatedly transmit prediction-based CSI reports using a reporting channel that is opened periodically. For example, the terminal can repeatedly transmit the same prediction-based CSI information using one or more periodic uplink channels after the prediction-based CSI report has been performed.
[0377] In another embodiment, based on aperiodic CSI reporting as in FIG. 18, the base station may direct additional uplink resources for repeated transmission of prediction-based CSI reporting. For example, the base station may additionally direct PUSCH resources for repeated transmission to the DCI that triggers the aperiodic CSI reporting.
[0378] In another embodiment, the uplink resource used for repeated transmission may be determined according to a predefined rule. For example, the resource used for repeated transmission may be set to a resource having the same OFDM symbol index and resource block index in the next slot after the first scheduled PUSCH.
[0379] As an alternative method, the base station may send an acknowledgment (ACK) to the terminal upon receiving a prediction-based CSI report. For example, the base station may use DCI to notify the terminal of the successful reception of the prediction-based CSI report.
[0380] If the terminal does not receive an acknowledgment within a preset time after the prediction-based CSI report, it may retransmit the relevant CSI information. For example, the time may be set and notified to the terminal by the base station, or it may be a value predefined by the system.
[0381] In one embodiment, when based on periodic / non-periodic CSI reporting as in FIG. 17, if the terminal does not receive an acknowledgment within a certain time after the prediction-based CSI report, it may report the CSI information again using the most recent periodic uplink channel that is subsequently opened.
[0382] In another embodiment, as shown in FIG. 18, when based on aperiodic CSI reporting, the base station may not transmit a separate acknowledgment. For example, if the base station fails to receive a prediction-based CSI report, it may re-trigger aperiodic CSI reporting using a new DCI.
[0383] In this way, by applying iterative transmission or retransmission procedures to prediction-based CSI reports, the decoding success probability of the base station can be improved and the reliability of the prediction-based CSI reports can be increased.
[0384] Example 4
[0385] This embodiment relates to a method for determining the payload size for a report based on whether an event defined in Example 1 has occurred.
[0386] In the aforementioned event-P-based prediction beam or CSI reporting method, the composition or size of the reported information may vary depending on whether an event occurs. For example, if event-P occurs, the terminal may report beam or CSI information for multiple time points within the prediction time interval, whereas if event-P does not occur, it may report only existing beam or CSI information for a single time point. In this way, the payload size of the CSI report may be configured differently depending on whether an event occurs.
[0387] However, since the base station receives the CSI report without being aware of whether an event has occurred, it may need to decode the CSI report by considering both cases where Event-P has occurred and where it has not. For example, the base station may perform multiple decoding attempts by assuming different payload sizes, which can increase implementation complexity due to blind decoding.
[0388] To mitigate the problem of increased decoding complexity, one or more of the following methods may be applied.
[0389] In one approach, the payload size of the CSI report can be set to be the same regardless of whether an event occurs. For example, the payload size of the CSI report can be set to the larger value between the payload size when Event-P occurs and the payload size when Event-P does not occur. Generally, since Event-P includes information from multiple time points, it may have a larger payload size. Therefore, the payload size of the CSI report can be set to match the size when Event-P occurs. In this case, if Event-P does not occur, the terminal can configure the CSI report to have the same payload size by applying zero padding to the remaining bits.
[0390] Alternatively, a method of encoding the CSI report by dividing it into multiple parts may be applied. For example, the CSI report may be divided into a first part and a second part. The first part may include information indicating whether Event-P has occurred, and the second part may include remaining beam or CSI information. For example, a terminal may report whether an event has occurred through the first part and report the actual beam or CSI value through the second part. A base station may first decode the first part to verify whether an event has occurred, and then decode the second part according to the payload size corresponding to the event state.
[0391] Alternatively, CSI reporting can be performed using different uplink resources depending on whether Event-P occurs. For example, the uplink resource for CSI reporting used when Event-P occurs and the uplink resource used when Event-P does not occur can be configured differently. The terminal can perform CSI reporting by selecting the corresponding uplink resource based on whether the event occurs.
[0392] In this case, the base station can verify whether a CSI report has been received by performing blind detection on multiple uplink resources. For example, the base station can determine whether a CSI report was transmitted from a given resource by checking the correlation or received power of the received signal using the Demodulation Reference Signal (DMRS) or transmission sequence corresponding to each uplink resource. This method can reduce implementation complexity compared to a method that performs multiple decodings for different payload sizes.
[0393] In this way, by adjusting the configuration method of the CSI report payload or the uplink resource allocation method, the blind decoding complexity that may occur in event-P-based predictive CSI reporting can be mitigated.
[0394] Additionally or alternatively, the following methods may be applied in relation to the proposed method of the present disclosure described above.
[0395] Among the aforementioned Event-P conditions, if the amount of time-domain change of the channel or beam within the prediction time interval is large (e.g., corresponding to the first condition), there is a possibility that the accuracy of the prediction result performed by the terminal may decrease. For example, if the time change of the channel or beam is rapid, the channel state at a future point in time predicted by the terminal may differ from the actual channel state.
[0396] Accordingly, the terminal may report information indicating whether the prediction result is valid for each prediction point within the prediction time interval. For example, if the number of prediction points included within the prediction time interval is 10, the terminal may use a 10-bit bitmap to indicate whether the prediction is valid for each point. For example, each bit may indicate whether the prediction result of the corresponding point is valid; a value of 1 indicates that the prediction result of that point is valid, and a value of 0 indicates that the prediction result of that point is invalid.
[0397] Additionally or alternatively, the terminal may report interval information of times when the prediction is valid to the base station. For example, the terminal may define a subset window within a set prediction time interval where the prediction result is valid and transmit information regarding that subset window to the base station. As an example, that subset window may be defined as the interval from the start time of the prediction time interval to a specific time point, and the terminal may report the end time of that subset window to the base station.
[0398] Additionally or alternatively, the terminal may report to the base station the number of times when the prediction is valid. For example, the terminal may report information indicating the number of times when a valid prediction was made within the prediction time interval.
[0399] By receiving the information described above, the base station can identify the time point or interval during which the prediction result is valid. Additionally, based on this information, the base station can reset the length of the prediction time interval, the number of prediction points, or the time interval between prediction points.
[0400] Meanwhile, although the embodiments described above focused on cases where predicted CSI or predicted beam information for multiple time points is reported, the proposed method of the present disclosure can also be applied to predictive CSI or predicted beam reporting for a single time point.
[0401] For example, if the Event-P condition is not satisfied, the terminal may report CSI or beam information for which no prediction was performed, in the same manner as the existing method, and if the Event-P condition is satisfied, it may report predicted CSI or predicted beam information for a single point in time. In such cases, the type of information reported may vary depending on whether an event occurs, but the payload size of the total CSI report may remain the same.
[0402] Additionally, if the Event-P condition is satisfied, the terminal may be configured to report only predicted CSI or predicted beam information, excluding existing non-predicted CSI or beam information.
[0403] In this way, by reporting validity information of prediction results together or adjusting the composition of the prediction CSI report, the base station can more accurately determine the reliability of the prediction information and improve the utilization of prediction-based channel status reporting.
[0404] FIGS. 19 and 20 illustrate the operation of a first device (e.g., a terminal) and a second device (e.g., a base station) that perform a terminal start report according to the proposed method of the present disclosure described above.
[0405] In the following description, "beam" may be replaced with expressions such as TCI status, QCL RS associated with TCI status, etc. For example, "current bema" may refer to the TCI status assigned to the terminal and / or the reference signal (RS) associated with the assigned TCI status, and "new bema" may refer to the RS associated with the configuration of the new beam.
[0406] FIG. 19 is a drawing for explaining the operation of a first device according to an embodiment of the present disclosure.
[0407] Referring to FIG. 19, the terminal can receive information from the base station that sets an event related to reporting channel state information or beam information for a predicted time interval (S1910).
[0408] For example, the above event may be an event in which the terminal predicts channel state information or beam information for a predicted time interval, and determines whether to report or the reporting method based on the prediction result. As an example, the occurrence condition of the above event may be defined based on the amount of change in the time domain of the channel state or beam within the predicted time interval and / or reliability information for the predicted channel state or beam.
[0409] Afterwards, the terminal can calculate a measurement value for the channel state or beam based on the measurement resources (S1920).
[0410] For example, the measurement resource may be a CSI-RS resource, an SSB (synchronization signal block) resource, or a reference signal resource for channel state measurement / beam measurement. The terminal may calculate a measurement value related to channel quality or beam quality based on the reference signal received through the measurement resource.
[0411] Afterwards, the terminal can predict channel state information or beam information for a predicted time interval based on the above measurement value and determine whether the conditions for the occurrence of the above event are satisfied (S1930).
[0412] For example, the above-mentioned prediction time interval may include multiple time points, and the multiple time points may be set spaced apart at regular time intervals. The start time of the above-mentioned prediction time interval may be determined based on one of the reception time at the measurement resource (e.g., reception time of the measurement RS), the CSI reference resource slot, or the reporting time of channel status information or beam information.
[0413] Additionally, according to the present disclosure, the length of the predicted time interval or the number of the plurality of time points may be set by a base station or determined by a terminal and reported to the base station.
[0414] Additionally, according to the present disclosure, the condition for the occurrence of the event may be defined based on a preset threshold value for the amount of change in the time domain of the channel state or beam within the predicted time interval. For example, if the amount of change in the time domain is greater than a preset first threshold value, the terminal may determine that the condition for the occurrence of the event is satisfied by determining that a significant change in the channel state or beam is likely to occur.
[0415] As another example, the occurrence condition of the above event may include a case where the amount of change in the time domain is smaller than a preset second threshold.
[0416] Additionally, according to the present disclosure, the conditions for the occurrence of the event may include cases where the reliability information for the predicted channel state or beam information is smaller than a preset third threshold. For example, if a plurality of time points are included in the prediction time interval, the reliability information may be determined as the average or minimum value of the probability values of the predicted channel state or beam for each time point.
[0417] Afterwards, the terminal can transmit channel state information or beam information for the predicted time interval to the base station based on the satisfaction of the conditions for the occurrence of the above event (S1940).
[0418] For example, when the conditions for the occurrence of the above event are satisfied, the terminal may transmit channel state information or beam information for multiple time points within the predicted time interval to the base station (e.g., when the first condition of the present disclosure is set as an event formation).
[0419] As another example, when the conditions for the occurrence of the above event are satisfied, the terminal may transmit channel state information or beam information for one point in time within the predicted time interval and additionally transmit information indicating the occurrence of the event (e.g., when the second condition of the present disclosure is set as an event formation).
[0420] Additionally, according to the present disclosure, if the conditions for the occurrence of the event are not satisfied, the terminal may transmit channel state information or beam information based on a measurement value (e.g., channel state information or beam information according to a conventional method without prediction) to a base station.
[0421] Additionally, according to the present disclosure, if the reporting of channel status information or beam information for a predicted time interval is set to a periodic reporting type or a semi-persistent reporting type, and if multiple reporting times are included within the predicted time interval, the transmission of channel status information or beam information may be omitted at some reporting times within the predicted time interval.
[0422] Additionally, according to the present disclosure, the transmission of channel state information or beam information for a predicted time interval may be performed repeatedly N times, where N is an integer greater than 1. The value of N may be set or indicated by a base station.
[0423] Additionally, according to the present disclosure, the payload size of channel state information or beam information for a predicted time interval may be determined based on whether the conditions for the occurrence of an event are satisfied. In this regard, the terminal may transmit to a base station a report comprising a first part containing information regarding whether an event has occurred and a second part containing channel state information or beam information for a predicted time interval.
[0424] Additionally, according to the present disclosure, the configuration of the aforementioned prediction time interval, event occurrence conditions, threshold value, reporting method, number of reports, or report payload may be set by a base station or determined by a terminal and reported to the base station.
[0425] The method described in the example of FIG. 19 can be performed by the wireless device (100) of FIG. 3. That is, the first device of FIG. 19 can be implemented as the wireless device (100). For example, one or more processors (102) of the wireless device (100) of FIG. 3 may be configured to receive information from a base station that sets an event related to reporting channel state information or beam information for a predicted time interval, calculate a measurement value for the channel state or beam based on a measurement resource, predict channel state information or beam information for the predicted time interval based on the measurement value to determine whether the conditions for the occurrence of an event are satisfied, and if the conditions for the occurrence of an event are satisfied, transmit the channel state information or beam information for the predicted time interval to the base station.
[0426] Furthermore, one or more memories (104) of the wireless device (100) may store instructions for performing the method described in the example of FIG. 19 or the examples described above when executed by one or more processors (102).
[0427] FIG. 20 is a drawing for explaining the operation of a second device according to an embodiment of the present disclosure.
[0428] Referring to FIG. 20, the base station can transmit information to the terminal that sets up an event related to reporting channel state information or beam information for a predicted time interval (S2010).
[0429] For example, the above event may be an event that allows the terminal to predict channel state information or beam information for a predicted time interval and determine whether to report based on the prediction result. As an example, the occurrence condition of the above event may be defined based on the amount of change in the time domain of the channel state or beam within the predicted time interval or reliability information for the predicted channel state or beam.
[0430] Subsequently, based on the satisfaction of the conditions for the occurrence of the above event, the base station may receive channel state information or beam information for the predicted time interval from the terminal (S2020).
[0431] The base station can perform wireless communication with the terminal based on received channel state information or beam information.
[0432] In the example of FIG. 20, specific details regarding the definition of event occurrence conditions, reporting information based on whether event occurrence is satisfied, configuration and setting / instruction of the prediction time interval, operation based on the set reporting type, repeated transmission of prediction information, determination of payload size, etc., are omitted as they overlap with the details described in FIG. 19.
[0433] The method described in the example of FIG. 20 can be performed by the wireless device (100) of FIG. 3. That is, the second device of FIG. 20 can be implemented as the wireless device (100). For example, one or more processors (102) of the wireless device (100) of FIG. 3 can be configured to transmit information to a terminal that sets an event related to reporting channel state information or beam information for a predicted time interval, and to receive channel state information or beam information for a predicted time interval from the terminal.
[0434] Furthermore, one or more memories (104) of the wireless device (100) may store instructions for performing the method described in the example of FIG. 20 or the examples described above when executed by one or more processors (102).
[0435] The various embodiments of the present disclosure described above can be applied to both beam reporting and channel state information (CSI) reporting. That is, the event-based predictive reporting method described in the present disclosure can be applied in the same or similar manner to CSI reporting procedures as well as to cases where beam-related information is reported.
[0436] Furthermore, although the description of this disclosure focuses on prediction beams or prediction CSIs in the time domain, the proposed method of this disclosure is not limited thereto. For example, the proposed method of this disclosure may also be applied to prediction beams or CSIs in the spatial domain or to prediction beams or CSIs in the frequency domain. In this case, only the domain in which the prediction is performed may be changed, and operations such as event condition evaluation, prediction information reporting, and determination of the reporting method may be applied in the same or similar manner.
[0437] Additionally, in various embodiments of the present disclosure, when a base station instructs a terminal to a specific parameter value or sets a specific configuration, such information may be transmitted through various control signals. For example, the information may be transmitted to the terminal via an RRC signal, MAC-CE, or DCI, etc.
[0438] Accordingly, the configurations and operations described in this disclosure are not limited to specific reporting types, specific prediction regions, or specific control signals, and can be applied in various modified forms.
[0439] The embodiments described above of the present disclosure may be applied independently. Additionally or alternatively, all or part of each operation of the embodiments described above of the present disclosure may be performed in combination.
[0440] 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. Regarding the method, A step of receiving from a base station information that sets an event related to reporting channel state information or beam information for a predicted time interval by the terminal; A step of calculating a measurement value for a channel state or a beam based on a measurement resource by the above terminal; A step of predicting channel state information or beam information for the predicted time interval based on the measurement value by the terminal above, and determining whether the conditions for the occurrence of the event are satisfied; and Based on the satisfaction of the conditions for the occurrence of the above event, the terminal transmits channel state information or beam information for the predicted time interval to the base station, the method comprising: A method in which the conditions for the occurrence of the above event are defined based on at least one of i) the amount of change in the time domain of the channel state or beam within the above prediction time interval or ii) the reliability information of the prediction for the above prediction time interval.
2. In Paragraph 1, A method in which, based on the fact that the conditions for the occurrence of the above event are not satisfied, the terminal is configured to transmit channel state information or beam information based on the above measurement value to the base station.
3. In Paragraph 1, A method in which the condition for the occurrence of the above event includes the case where the amount of change in the time domain is greater than a preset first threshold.
4. In Paragraph 3, A method in which, based on the satisfaction of the conditions for the occurrence of the above event, the terminal is configured to transmit channel state information or beam information for a plurality of time points within the above-mentioned prediction time interval.
5. In Paragraph 1, A method in which the condition for the occurrence of the above event includes the case where the amount of change in the time domain is smaller than a preset second threshold.
6. In Paragraph 5, A method in which, based on the satisfaction of the conditions for the occurrence of the above event, the terminal is configured to transmit channel state information or beam information for one point in time within the above prediction time interval and additionally transmit information indicating the occurrence of the above event.
7. In Paragraph 1, A method in which the condition for the occurrence of the above event includes the case where the reliability information is smaller than a preset third threshold.
8. In Paragraph 7, A method in which, based on the inclusion of multiple time points in the above-mentioned prediction time interval, the reliability information is determined as the average or minimum value of the probability values of the channel state or beam predicted for each time point.
9. In Paragraph 1, The above-mentioned predicted time interval includes multiple time points, and A method in which the above-mentioned multiple points in time are set spaced apart at regular time intervals.
10. In Paragraph 9, A method in which the start time of the above-mentioned prediction time interval is determined based on one of i) the reception time at the measurement resource, ii) the CSI reference resource slot, or iii) the reporting time of channel status information or beam information.
11. In Paragraph 9, A method in which the length of the predicted time interval or the number of the plurality of time points is set by the base station or determined by the terminal and reported to the base station.
12. In Paragraph 1, Based on the fact that the reporting of channel state information or beam information for the above-mentioned prediction time interval is set to a periodic reporting type or a semi-persistent reporting type, and that multiple reporting timestamps are included within the above-mentioned prediction time interval, A method in which the transmission of channel status information or beam information is omitted at some reporting points within the above-mentioned prediction time interval.
13. In Paragraph 1, The transmission of channel state information or beam information for the above-mentioned prediction time interval is performed repeatedly N times, where N is an integer greater than 1, and The above N value is set or directed by the base station, method.
14. In Paragraph 1, A method for determining the payload size of channel state information or beam information for the predicted time interval based on whether the conditions for the occurrence of the above event are satisfied.
15. In Paragraph 1, Based on the satisfaction of the conditions for the occurrence of the above event, the terminal is configured to transmit a report including a first part and a second part, and The above first part includes information regarding whether the event has occurred, and A method in which channel state information or beam information for the above-mentioned predicted time interval is included in the second part.
16. One or more transceivers; and It includes one or more processors connected to the above one or more transmitters and receivers, and The above one or more processors are: The terminal receives from the base station information for setting an event related to reporting channel state information or beam information for a predicted time interval; The above terminal calculates a measurement value for a channel state or beam based on a measurement resource; By the above terminal, channel state information or beam information for the above-mentioned prediction time interval is predicted based on the above-mentioned measurement value, and the occurrence condition of the above-mentioned event is determined; Based on the satisfaction of the conditions for the occurrence of the above event, the terminal is configured to transmit channel state information or beam information for the above-mentioned prediction time interval to the base station, A device in which the conditions for the occurrence of the above event are defined based on at least one of i) the amount of change in the time domain of the channel state or beam within the above prediction time interval or ii) reliability information of the prediction for the above prediction time interval.
17. Regarding the method, A step of transmitting to a terminal information that sets an event related to reporting channel state information or beam information for a predicted time interval by a base station; and Based on the satisfaction of the conditions for the occurrence of the above event, the base station receives channel state information or beam information for the predicted time interval from the terminal, the method comprising: The above event is configured such that the terminal calculates a measurement value for a channel state or beam based on a measurement resource, predicts channel state information or beam information for the predicted time interval based on the measurement value, and determines whether the conditions for the occurrence of the event are satisfied. A method in which the conditions for the occurrence of the above event are defined based on at least one of i) the amount of change in the time domain of the channel state or beam within the above prediction time interval or ii) the reliability information of the prediction for the above prediction time interval.
18. One or more transceivers; and It includes one or more processors connected to the above one or more transmitters and receivers, and The above one or more processors are: The base station transmits information to the terminal that sets up an event related to the reporting of channel state information or beam information for a predicted time interval; Based on the satisfaction of the conditions for the occurrence of the above event, the base station is configured to receive channel state information or beam information for the predicted time interval from the terminal, The above event is configured such that the terminal calculates a measurement value for a channel state or beam based on a measurement resource, predicts channel state information or beam information for the predicted time interval based on the measurement value, and determines whether the conditions for the occurrence of the event are satisfied. A device in which the conditions for the occurrence of the above event are defined based on at least one of i) the amount of change in the time domain of the channel state or beam within the above prediction time interval or ii) reliability information of the prediction for the above prediction time interval.
19. One or more processors; and A processing device comprising one or more computer memories that are operably connected to one or more processors and store instructions for performing a method according to any one of claims 1 to 15 based on execution by one or more processors.
20. One or more non-transitory computer-readable storage media storing one or more instructions that are executed by one or more processors to control the execution of a method according to any one of claims 1 through 15.