Method and apparatus for beam indication in wireless communication system

Abstract

According to an embodiment disclosed in the present specification, a method performed by a terminal in a wireless communication system comprises the steps of: receiving configuration information; receiving a beam indication; and receiving a physical signal / channel based on the beam indication. The configuration information includes information on a plurality of reference signals (RSs) for beam indication. A plurality of RS sets are configured based on the plurality of RSs. Beam indication is performed based on one of the plurality of RS sets.

Description

Technical Field

[0001] The present disclosure relates to a method and apparatus for beam indication in a wireless communication system. Background Art

[0002] To provide voice services while ensuring user activity, a mobile communication system has been developed. However, the area of the mobile communication system has expanded to data services in addition to voice. Due to the explosive increase in current traffic, resource shortages have occurred, so users need higher-speed services. Therefore, a more advanced mobile communication system is needed.

[0003] Requirements for the next-generation mobile communication system need to be able to support accommodation of explosive data traffic, a significant increase in data rate per user, accommodation of a significant increase in the number of connected devices, very low end-to-end latency, and high energy efficiency. To this end, various technologies have been studied, such as dual connectivity, massive multiple-input multiple-output (MIMO), in-band full duplex, non-orthogonal multiple access (NOMA), ultra-wideband support, and device networking.

[0004] Regarding beam management, set A and set B are defined. Specifically, according to BM-Case1, the UE estimates / determines the beam of set A (e.g., the preferred beam among the beams of set A) based on the measurement of the beam of set B (e.g., the measurement of the RS related to the beam of set B). Summary of the Invention

[0005] Technical Problem

[0006] In the beam prediction operation based on the NW-side AI / ML model, there may be a situation where it is necessary to change, (re)train, update, or fallback to the traditional operation due to changes in the position, movement, or rotation of the UE. If any of the above situations occur, it is necessary to change the beam set for beam indication. However, in the existing method, changing the beam set for beam indication is not supported. The following problems may occur. Even if the beam set previously used for beam indication changes due to changes in the NW-side AI / model, (re)training, traditional fallback, etc., the UE may interpret the beam indication based on the existing beam set. That is, the beam indicated by the base station and the beam determined by the UE may be different. Therefore, the accuracy of beam indication and the reliability of the signaling operation based on the indicated beam may be reduced.

[0007] The object of the present disclosure is to propose a method for solving the above problems.

[0008] The technical objects to be achieved by the present disclosure are not limited to those described only by way of example above, and other technical objects not mentioned can be clearly understood by those skilled in the art to which the present disclosure pertains from the following description.

[0009] Technical solution

[0010] A method performed by a user equipment (UE) in a wireless communication system according to an embodiment of the present disclosure includes: receiving configuration information, receiving a beam indication, and receiving a physical signal / channel based on the beam indication.

[0011] The configuration information includes information for a plurality of reference signals (RSs) used for beam indication. A plurality of RS sets are configured based on the plurality of RSs. Beam indication is performed based on one of the plurality of RS sets.

[0012] The plurality of RS sets may include a first RS set and a second RS set.

[0013] The beam indication may include an indicator indicating one of the first RS set and the second RS set. The number of bits related to the beam indication may be determined based on the indicator. The number of bits related to the beam indication may be i) a first number of bits based on the number of RSs belonging to the first RS set, or ii) a second number of bits based on the number of RSs belonging to the second RS set.

[0014] The first RS set may be composed of a plurality of RSs, and the second RS set may be composed of some of the plurality of RSs.

[0015] The RSs belonging to the second RS set may include the RSs for beam measurement among the plurality of RSs.

[0016] The RSs belonging to the second RS set may include the RSs determined based on a criterion related to the RS index among the plurality of RSs.

[0017] The first RS set may be composed of a plurality of RSs, and the second RS set may be composed of the RSs mapped to the plurality of RSs.

[0018] The beam indication may include an indicator having a number of bits based on the number of the plurality of RSs.

[0019] Based on the beam indication being related to the first RS set, the RS indicated by the indicator may be determined as the RS related to the physical signal / channel.

[0020] Based on the beam indication being related to the second RS set, the RSs mapped to the RS indicated by the indicator may be determined as the RSs related to the physical signal / channel.

[0021] Each RS belonging to the second RS set may be mapped to two or more RSs among the plurality of RSs.

[0022] A quasi - co - location (QCL) relationship may be configured between each RS belonging to the second RS set and two or more RSs among the plurality of RSs.

[0023] A user equipment (UE) operating in a wireless communication system according to another embodiment of the present disclosure includes one or more transceivers, one or more processors, and one or more memories connected to the one or more processors and storing instructions.

[0024] Based on being executed by the one or more processors, the instructions configure the one or more processors to perform all steps of any one of the methods performed by the UE.

[0025] An apparatus according to another embodiment of the present disclosure includes one or more memories and one or more processors functionally connected to the one or more memories.

[0026] The one or more memories store instructions that, based on being executed by the one or more processors, configure the one or more processors to perform all steps of any one of the methods performed by the UE.

[0027] One or more non - transitory computer - readable media according to another embodiment of the present disclosure store instructions. The instructions executable by one or more processors configure the one or more processors to perform all steps of any one of the methods performed by the UE.

[0028] A method performed by a base station in a wireless communication system according to another embodiment of the present disclosure includes: sending configuration information, sending a beam indication, and sending a physical signal / channel based on the beam indication.

[0029] The configuration information includes information for a plurality of reference signals (RSs) for beam indication. A plurality of RS sets are configured based on the plurality of RSs. The beam indication is performed based on one of the plurality of RS sets.

[0030] A base station operating in a wireless communication system according to another embodiment of the present disclosure includes one or more transceivers, one or more processors, and one or more memories connected to the one or more processors and storing instructions.

[0031] Based on being executed by the one or more processors, the instructions configure the one or more processors to perform all steps of any one of the methods performed by the base station.

[0032] Beneficial effects

[0033] According to an embodiment of the present disclosure, the beam indication includes information for one RS set among a plurality of RS sets. The set associated with the beam indicated to the UE can be effectively and rapidly changed, thereby preventing the accuracy of the beam indication from deteriorating after a specific time. As a specific example, the specific time may include the following i) to iii).

[0034] i) The time after changing or (re)training the NW-side AI / model

[0035] ii) The time after the beam indication method is changed from an AI / model-based method to an existing method

[0036] iii) The time after the beam indication method is changed from the existing method to an AI / model-based method

[0037] That is, according to the existing method, the accuracy of the beam indication performed after the above times i) to iii) may be reduced. On the other hand, according to an embodiment of the present disclosure, since the RS set associated with the beam indication is indicated together, the accuracy of the beam indication is not reduced. In other words, regarding the beam indication after performing a specific operation involving a change in the beam set, it is possible to prevent the beam indication from being interpreted based on the existing beam set.

[0038] The effects that can be achieved by the present disclosure are not limited to those described above by way of example, and other effects and advantages of the present disclosure will be more clearly understood by those skilled in the art from the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 An example of beamforming using SSB and CSI-RS is illustrated.

[0040] Figure 2 It is a flowchart showing an example of a DL BM process using SSB.

[0041] Figure 3 A functional framework of an AI / ML model is illustrated.

[0042] Figure 4 A signaling process according to an embodiment of the present disclosure is illustrated.

[0043] Figure 5 It is a flowchart illustrating a method performed by a user equipment according to an embodiment of the present disclosure.

[0044] Figure 6 It is a flowchart illustrating a method performed by a base station according to another embodiment of the present disclosure.

[0045] Figure 7Illustrates the configurations of a first device and a second device according to embodiments of the present disclosure. Detailed implementation

[0046] The following will be combined with the attached Figure 1 The detailed description to be disclosed below will describe exemplary embodiments of the present disclosure, rather than describing unique embodiments for implementing the present disclosure. The following detailed description includes details that provide a complete understanding of the present disclosure. However, those skilled in the art know that the present disclosure can be implemented without these details.

[0047] In some cases, to prevent obscuring the concepts of the present disclosure, known structures and devices may be omitted, or may be illustrated in block diagram format based on the core functions of each structure and device.

[0048] Hereinafter, the downlink (DL) means communication from the base station to the terminal, and the uplink (UL) means communication from the terminal to the base station. In the downlink, the transmitter may be part of the base station, and the receiver may be part of the terminal. In the uplink, the transmitter may be part of the terminal, and the receiver may be part of the base station. The base station may be represented as a first communication device, and the terminal may be represented as a second communication device. The base station (BS) may be replaced with terms including a fixed station, Node B, evolved Node B (eNB), next-generation Node B (gNB), base transceiver system (BTS), access point (AP), network (5G network), AI system, roadside unit (RSU), vehicle, robot, unmanned aerial vehicle (UAV), AR (augmented reality) device, VR (virtual reality) device, etc. In addition, the terminal may be fixed or mobile, and may be replaced with terms including user equipment (UE), mobile station (MS), user terminal (UT), mobile subscriber station (MSS), subscriber station (SS), advanced mobile station (AMS), wireless terminal (WT), machine type communication (MTC) device, machine-to-machine (M2M) device, and device-to-device (D2D) device, vehicle, robot, AI module, unmanned aerial vehicle (UAV), AR (augmented reality) device, VR (virtual reality) device, etc.

[0049] Beam management (BM)

[0050] As a layer 1 (L1) / layer 2 (L2) process for obtaining and maintaining a set of base station (e.g., gNB, TRP, etc.) and / or terminal (e.g., UE) beams that can be used for downlink (DL) and uplink (UL) transmission / reception, the BM process may include the following processes and terms.

[0051] - Beam measurement: An operation of measuring the characteristics of a beamformed signal received by the eNB or UE.

[0052] - Beam determination: The operation of selecting a transmit (Tx) beam / receive (Rx) beam of an eNB or a UE by the eNB or the UE.

[0053] - Beam scanning: The operation of covering a spatial region using transmit and / or receive beams for a time interval according to a predetermined scheme.

[0054] - Beam reporting: The operation of a UE reporting information on beamformed signals based on beam measurements.

[0055] The BM process can be divided into (1) a DL BM process using a synchronization signal (SS) / physical broadcast channel (PBCH) block or CSI-RS and (2) a UL BM process using a sounding reference signal (SRS).

[0056] In addition, each BM process may include a Tx beam scanning for determining a Tx beam and an Rx beam scanning for determining an Rx beam.

[0057] DL BM

[0058] The DL BM process may include (1) the transmission of a beamformed DL reference signal (RS) (e.g., CSI-RS or SS block (SSB)) by the eNB and (2) beam reporting by the UE.

[0059] Here, the beam reporting includes a preferred DL RS identifier (ID) and the L1 reference signal received power (RSRP) corresponding to the preferred DL RS identifier (ID).

[0060] The DL RS ID may be an SSB resource indicator (SSBRI) or a CSI-RS resource indicator (CRI).

[0061] Figure 1 Examples of beamforming using SSB and CSI-RS are illustrated.

[0062] As Figure 1 shown, the SSB beam and the CSI-RS beam can be used for beam management. The measurement metric is the L1-RSRP for each resource / block. The SSB can be used for coarse beam management, and the CSI-RS can be used for fine beam management. The SSB can be used for both Tx beam scanning and Rx beam scanning.

[0063] The Rx beam scanning using the SSB can be performed when the UE changes the Rx beam for the same SSBRI across multiple SSB bursts. Here, one SS burst includes one or more SSBs, and one set of SS bursts includes one or more SSB bursts.

[0064] Figure 2It is a flowchart showing an example of the DL BM process using SSB.

[0065] Configuration of beam reporting using SSB is performed during CSI / beam configuration in the RRC connected state (or RRC connected mode).

[0066] - The UE receives a CSI-ResourceConfig IE including CSI-SSB-ResourceSetList from the eNB, and CSI-SSB-ResourceSetList includes SSB resources for BM (S210).

[0067] Table 1 shows an example of the CSI-ResourceConfig IE. As shown in Table 1, the BM configuration using SSB is not defined separately, and the SSB is configured similarly to the CSI-RS resource.

[0068] [Table 1]

[0069]

[0070] In Table 1, the csi-SSB-ResourceSetList parameter represents a list of SSB resources for beam management and reporting in a resource set. Here, the SSB resource set can be configured as {SSBx1, SSBx2, SSBx3, SSBx4, …}. For example, the SSB index can be defined from 0 to 63.

[0071] - The UE receives SSB resources from the eNB based on CSI-SSB-ResourceSetList (S220).

[0072] - When CSI-reportConfig associated with the reporting of SSBRI and L1-RSRP is configured, the UE (beam) reports the corresponding best SSBRI and L1-RSRP to the eNB (S230).

[0073] In other words, when the reportQuantity of the CSI-reportConfig IE is configured as “ssb-Index-RSRP”, the UE reports the corresponding best SSBRI and L1-RSRP to the eNB.

[0074] In addition, when CSI-RS resources are configured in the same OFDM symbol as the SSB (SS / PBCH block) and “QCL-TypeD” applies, the UE can assume that the CSI-RS and SSB are quasi-co-located from the perspective of “QCL-TypeD”.

[0075] Here, QCL TypeD can mean that from the perspective of the spatial Rx parameter, the antenna port is QCL. When the UE receives multiple DL antenna ports with QCL TypeD relationships, the same Rx beam can be applied. In addition, the UE does not expect CSI-RS to be configured in the REs that overlap with the REs of the SSB.

[0076] BM Enhancement in NR Rel-16

[0077] The DL / UL beam indication standardized in 3GPP NR Rel-15 has been designed to indicate the beams for each DL / UL channel / RS resource respectively to ensure beam indication flexibility, and this indication method has been designed separately for each channel / RS.

[0078] This design direction ultimately has the following problems: The base station must indicate the beam changes for each channel / RS resource to multiple UEs communicating with the base station using a single beam in order to change the serving beam for multiple UEs, which results in large signaling overhead and large beam change latency. With UL beam changes, it is necessary to change the UL power control related parameters, especially the path loss RS (PL RS), for each UL channel / RS, which also results in signaling overhead / latency problems. To complement these drawbacks, five features were introduced in Rel-16. Table 2 below shows these five features.

[0079] [Table 2]

[0080]

[0081]

[0082] In Rel-16, in addition to the above enhancements related to beam / PL RS indication, enhancements related to beam reporting were also made. In Rel-15, a mode was supported where the UE measures / reports L1-RSRP for each beam RS. However, in an environment with high inter-beam interference, it is difficult to ensure that a specific beam RS has good quality as a serving beam just because the L1-RSRP (i.e., the received strength of a specific beam RS) is high. In other words, the UE may select a beam with high received strength but high beam interference and report this beam to the base station. To overcome this drawback, Rel-16 supports a new beam reporting mode where the base station configures resources for interference measurement and RS for channel measurement, and the UE measures L1-SINR for the channel resources and interference resources based on this and reports several RSs with high L1-SINR values.

[0083] BM Enhancement in NR Rel-17

[0084] As described above, various BM enhancements were made in Rel-16. Specifically, features were created that can significantly reduce the signaling overhead / delay associated with beam indication methods. However, there is still no configuration / indication of a channel / RS unified beam for UEs operating with a single serving beam.

[0085] Motivated by this, Rel-17 will standardize the channel / RS unified beam configuration / indication method. In NR, DL beams are indicated by transmitting a configuration indicator (TCI), and thus are referred to as unified TCI states. Existing TCI states are configured / indicated separately for each DL RS / channel, but the unified TCI state is characterized by a unified configuration / indication. Basically, the DL unified TCI state indicates the QCL type-D RS that is uniformly applied to (some) PDCCH, PDSCH, and (some) CSI-RS resources, and the UL unified TCI state indicates the spatial relation RS (and PL RS) that is uniformly applied to (some) PUCCH, PUSCH, and (some) SRS. For UEs that have established beam correspondence, since the UL spatial relation and PL RS can also be matched with the DL beam RS in the same way as the Rel-16 default spatial relation / PLRS characteristics, the channels / RSs to which the unified TCI state is applied can cover both DL channels / RSs and UL channels / RSs. This is called the joint DL / UL TCI state. That is, the following two modes will be supported.

[0086] - Joint DL / UL TCI configuration / indication mode: The DL RS configured / indicated in the joint TCI state can be applied not only as the QCL type-D RS for DL channels / RSs, but also as the spatial relation RS (and PL RS) for UL channels / RSs. That is, if an update to the joint TCI state is indicated, the beam RS (or / and PL RS) used for DL channels / RSs and UL channels / RSs can be changed together.

[0087] - Separate DL and UL TCI configuration / indication mode: The QCL type-D source RS for DL channels / RSs is unified and configured / indicated by the DL TCI state, and the spatial relation RS (and PL RS) for UL channels / RSs is unified and configured / indicated by the UL TCI state. The DL TCI state and the UL TCI state are configured / indicated separately.

[0088] The DL / UL / Combined TCI status will be indicated / updated via MAC-CE and / or DCI. More specifically, one or more of the multiple TCI statuses configured by RRC (referred to as the TCI status pool) are activated by MAC-CE. If multiple TCI statuses are activated by MAC-CE, one of the multiple TCI statuses is indicated by DCI.

[0089] DCI indication will be supported via downlink DCI formats (DCI1-1 / 1-2) that support the TCI field, and will be supported in both cases with and without PDSCH scheduling. In the latter case, since PDSCH scheduling is omitted (similar to the DCI-based semi-persistent scheduling (SPS) release method), ACK transmission by the UE for the corresponding DCI will be supported.

[0090] Enhancements related to beam reporting will be made in Rel-17. The Rel-17 beam reporting mode will support the mode where the UE measures / reports the best beam RS for each TRP, targeting a multi-TRP environment. For this purpose, if the beam measurement RS set / group is divided into two subsets / subgroups and the base station configures them, the UE will select RSs for each subset / subgroup and report them together with the quality values (L1-RSRP, [L1-SINR]) of the corresponding RSs.

[0091] AIML-related description

[0092] With the technological progress of artificial intelligence / machine learning (AI / ML), the nodes and UEs that make up the wireless communication network become more and more intelligent / advanced.

[0093] Specifically, due to the intelligence of the network / base station, it is expected that various network / base station decision parameters can be quickly optimized and derived / applied based on various environmental parameters.

[0094] The environmental parameters can include at least one of the distribution / location of base stations, the distribution / location / materials of buildings / furniture, the location / moving direction / speed of the UE, or climate information. However, the above parameters are only examples, and in addition to the listed parameters, the environmental parameters can also include other environmental parameters related to the network / base station decision parameters.

[0095] The network / base station decision parameters can include at least one of the transmit / receive power of each base station (BS), the transmit power of each UE, the precoder / beam of the BS / UE, the time / frequency resource allocation for each UE, or the duplex method of each BS. However, the above parameters are only examples, and in addition to the listed parameters, the network / base station decision parameters can also include other parameters determined by the network / base station.

[0096] In line with this trend, many standardization organizations (e.g., 3GPP, O-RAN) are considering introducing AI / ML, and related research is also actively underway.

[0097] In a narrow sense, AI / ML can simply be referred to as artificial intelligence based on deep learning, but conceptually, it can be classified as follows.

[0098] - Artificial intelligence: It is any automation that allows machines to perform tasks that humans would otherwise do.

[0099] - Machine learning: It refers to a technology in which machines learn patterns from data for decision-making on their own, without explicit programming rules.

[0100] - Deep learning: It is a model based on artificial neural networks and allows machines to perform feature extraction and decision-making simultaneously based on unstructured data. The algorithm depends on a multi-layer network composed of interconnected nodes for feature extraction and transformation, which is inspired by the biological nervous system (i.e., neural network). Common deep learning network architectures include deep neural networks (DNN), recurrent neural networks (RNN), and convolutional neural networks (CNN).

[0101] As mentioned above, artificial intelligence (AI) is the broadest concept of AI / ML, and deep learning is the narrowest concept of AI / ML. Machine learning (ML) can be interpreted as a concept that is narrower than artificial intelligence and broader than deep learning.

[0102] Types of AI / ML Based on Various Criteria

[0103] - Offline vs. online

[0104] Offline Learning

[0105] - Offline learning faithfully follows the sequential process of database collection, learning, and prediction. That is, collection and learning can be performed offline, and the completed program can be installed on-site and used for prediction work. In most cases, this offline learning method is used.

[0106] Online Learning

[0107] - Online learning refers to a method of gradually improving performance through incremental learning by utilizing additional generated data, taking advantage of the fact that data that can be used for recent learning is continuously generated via the Internet.

[0108] Classification Based on AI / ML Framework Concepts

[0109] - Centralized learning

[0110] In centralized learning, when the training data collected from multiple different nodes is reported to a centralized node, all data resources / storage / learning (e.g., supervised learning, unsupervised learning, reinforcement learning, etc.) are performed in a centralized node.

[0111] - Federated learning

[0112] Federated learning is data-driven, where there is a collective model across data owners of various distributions. Instead of collecting data into the model, the AI / ML model is imported into the data sources, allowing local nodes / individual devices to collect data and train their own model copies, thus eliminating the need to report the source data to a centralized node.

[0113] In federated learning, the parameters / weights of the AI / ML model are sent back to the centralized node to support general model training. Federated learning has advantages in terms of improved computational speed and information security. That is, the process of uploading personal data to a central server is unnecessary, and leakage and misuse of personal information can be prevented.

[0114] - Distributed learning

[0115] Distributed learning refers to the concept of cluster scaling and distribution of the machine learning process across nodes. The training model is shared across multiple nodes, which are split and operated simultaneously to accelerate model training.

[0116] Classification According to Learning Methods

[0117] - Supervised learning

[0118] Supervised learning is a machine learning task aimed at learning a mapping function from input to output given a labeled dataset. The input data is called training data and has known labels or outcomes. Examples of supervised learning are as follows.

[0119] 1) Regression: Linear regression, Logistic regression

[0120] 2) Instance-based algorithms: k-Nearest Neighbor (KNN)

[0121] 3) Decision tree algorithms: CART

[0122] 4) Support Vector Machines: SVM

[0123] 5) Bayesian algorithms: Naive Bayes

[0124] 6) Ensemble algorithms: Extreme Gradient Boosting, Bagging: Random Forest

[0125] Supervised learning can be further grouped into regression and classification problems, where classification is predicting labels and regression is predicting quantities.

[0126] - Unsupervised learning

[0127] Unsupervised learning is a machine learning task that aims to learn a function that describes the hidden structure in unlabeled data. The input data is not labeled, and there are no known results. Some examples of unsupervised learning include K-means clustering, principal component analysis (PCA), non-linear independent component analysis (ICA), and long short-term memory (LSTM).

[0128] - Reinforcement learning

[0129] In reinforcement learning (RL), the agent aims to optimize a long-term goal by interacting with the environment based on a trial-and-error process and is goal-oriented learning based on the interaction with the environment. Examples of RL algorithms are as follows.

[0130] 1) Q-learning

[0131] 2) Multi-armed bandit learning

[0132] 3) Deep Q-network

[0133] 4) State-Action-Reward-State-Action (SARSA)

[0134] 5) Temporal difference learning

[0135] 6) Actor-Critic reinforcement learning

[0136] 7) Deep deterministic policy gradient

[0137] 8) Monte Carlo tree search

[0138] Reinforcement learning can also be grouped into model-based reinforcement learning and model-free reinforcement learning.

[0139] Model-based reinforcement learning: It refers to RL algorithms that use a predictive model and use various dynamic states of the environment and the model in which these states bring rewards to obtain the transition probability between states.

[0140] Model-free reinforcement learning: It refers to RL algorithms based on the value or policy that maximizes future rewards. The multi-agent environment / state is computationally less complex and does not require an accurate representation of the environment.

[0141] RL algorithms can also be classified as value-based RL and policy-based RL, policy-based RL and off-policy RL, etc.

[0142] Representative Models of Deep Learning

[0143] 1. Feedforward neural network (FFNN)

[0144] The FFNN consists of an input layer, a hidden layer, and an output layer.

[0145] 2. Recurrent Neural Network (RNN)

[0146] RNN is a type of artificial neural network where hidden nodes are connected by directed edges to form a directed cycle. It is a model suitable for processing sequentially occurring data such as speech and text.

[0147] 3. Convolutional Neural Network (CNN)

[0148] CNNs are used for two purposes: reducing model complexity and extracting good features by applying convolutional operations commonly used in the fields of video processing or image processing.

[0149] - Kernel or filter: It refers to a unit / structure that applies weights to the input of a specific range / cell.

[0150] - Stride: It refers to the range of movement of the kernel within the input.

[0151] - Feature map: It refers to the result of applying the kernel to the input.

[0152] - Padding: It refers to the value added to adjust the size of the feature map.

[0153] - Pooling: It refers to an operation that reduces the size of the feature map by downsampling the feature map (e.g., max pooling, average pooling).

[0154] 4. Autoencoder

[0155] An autoencoder refers to a neural network that receives a feature vector x as input and outputs the same or a similar vector x'. The input nodes and output nodes of an autoencoder have the same features.

[0156] Figure 3 Illustrates the functional framework of the AI / ML model.

[0157] In Figure 3 In the functional framework shown, the definition of each term and the operation of each function can be based on Table 3 below.

[0158] [Table 3]

[0159]

[0160] Dataset

[0161] The datasets used in AI / ML are classified into training data, validation data, and test data, and their definitions are as follows.

[0162] - Training data

[0163] Dataset for training a model

[0164] - Validation data

[0165] Dataset for validating a model for which training has been completed

[0166] Validation data is a dataset that is often used to prevent overfitting of the training dataset.

[0167] Validation data is a dataset used to select the best model among various models trained during the training process. Therefore, validation data can be regarded as a dataset related to training.

[0168] - Test data

[0169] Test data is a dataset for final evaluation. Test data is independent of training.

[0170] The dataset can use a training set that includes the above data in a predetermined ratio.

[0171] For example, a training set including training data and validation data in a ratio of 8:2 or 7:3 can be used.

[0172] For example, a training set including training data, validation data, and test data in a ratio of 6:2:2 can be used.

[0173] Collaboration Level

[0174] The cooperation level can be defined as follows according to whether the AI / ML function between the base station and the UE is capable.

[0175] [Table 4]

[0176]

[0177] The cooperation levels shown in Table 4 are examples, and can be modified and utilized differently from the illustrated examples based on the implementation method. For example, a cooperation level combining two or more of the shown cooperation levels can be defined / utilized. For example, a cooperation level not including one or more of the shown cooperation levels can be utilized.

[0178] In the present disclosure, depending on the context, " / " means "and", "or", or "and / or". In the present disclosure, "beam" can represent a source RS for a "spatial filter" or "spatial relationship", and can be interpreted as a QCL (type D) RS or a TCI state or (in the case of the uplink) a spatial relationship RS.

[0179] As an example, in the present disclosure, a "beam" may represent a spatial filter determined based on a reference RS or a source RS. The spatial filter may include a spatial domain filter, a spatial domain transmit filter, and a spatial domain receive filter.

[0180] As an example, a beam related to UL may be referred to as i) a spatial filter (for uplink transmission or uplink reception), ii) a spatial domain filter (for uplink transmission or uplink reception), iii) an uplink spatial domain transmit filter, iv) an uplink spatial domain receive filter, v) an uplink transmit spatial filter (UL Tx spatial filter), or vi) an uplink receive spatial filter (UL Rx spatial filter).

[0181] As an example, a beam related to DL may be referred to as i) a spatial filter (for downlink transmission or downlink reception), ii) a spatial domain filter (for downlink transmission or downlink reception), iii) a downlink spatial domain transmit filter, iv) a downlink spatial domain receive filter, v) a downlink transmit spatial filter (DL Tx spatial filter), or vi) a downlink receive spatial filter (DL Rx spatial filter).

[0182] According to the existing 3GPP NR beam indication scheme, a beam RS ID (e.g., CRI, SSBRI) is indicated as the source / reference RS to be used for the transmission and / or reception of a target RS / channel.

[0183] According to the DL beam indication method, in terms of the spatial Rx parameters for a target channel / RS (QCL type D RS), the base station designates the QCL source RS to the UE as a specific CSI-RS resource or an SSB resource. The UE that receives this indication may use the beam of the received source RS to receive the target channel / RS. At this time, the UE is not forced to receive the target channel / RS with the same UE beam as the beam of the received source RS. The base station notifies the UE of the source RS in order to prevent unnecessary receive beam search by the UE.

[0184] According to the UL beam indication method, in terms of the spatial Rx parameters for a target channel / RS (spatial relation RS), the base station designates the QCL source RS to the UE as a specific CSI-RS resource, an SSB resource, or an SRS resource.

[0185] When the source RS is a DL RS (e.g., CSI-RS, SSB), the UE receiving the indication transmits the target UL channel / RS using the Tx beam corresponding to the Rx beam used for receiving the DL RS. When the source RS is a UL RS (e.g., SRS), the UE receiving the indication transmits the target UL channel / RS using the Tx beam corresponding to the Rx beam used for transmitting the UL RS. The DL beam RS (e.g., QCL type D RS) can be indicated while being included in the DL TCI state, and the UL beam RS (e.g., spatial relation RS) can be indicated while being included in the UL TCI state.

[0186] In addition, (for UEs that establish a (one-to-one) correspondence between the Tx beam and the Rx beam), the source RS for the DL and UL beams can be the same DL RS (e.g., CSI-RS, SSB) resource. A joint DL / UL TCI state can be configured / indicated to comprehensively indicate the DL RS.

[0187] For ease of description, the above TCL / QCL / spatial relation RS indication methods are collectively referred to as "beam indication" below.

[0188] 3GPP Rel-18 began studying how to use AI / ML in the air interface. This study item (SI) covers beam management, CSI, and positioning as the main use cases of AI / ML. This disclosure covers the beam management method among them.

[0189] There may be two use cases for performing improved beam management using AI / ML: "improving beam management performance through spatial beam prediction" and "improving beam management performance through temporal beam prediction". This disclosure mainly considers "improving beam management performance through spatial beam prediction", but it should be noted that the techniques in this disclosure can be modified and applied to "improving beam management performance through temporal beam prediction".

[0190] "Improving beam management performance through spatial beam prediction" is a use case that achieves more improved beam management accuracy with lower RS overhead based on UE location / mobility information, etc., as the measurement results of the current / past beam RS. In this case, the AI / ML of the UE and / or the network (NW) can be used for the spatial beam prediction operation. For example, AI / ML can be used to achieve performance equivalent to beam selection from a large number of beam RS based on the results measured from a small number of beam RS.

[0191] The AI / ML-based beam prediction can be defined based on the input and output related to the AI / ML model of the (UE and / or NW).

[0192] For example, the input may be information related to the measurement of a beam (e.g., RS associated with the beam), and the output may be information about a specific beam (e.g., the ID of the RS associated with the specific beam).

[0193] For example, the input may be the reference signal received power (RSRP) of the beams in a first set, and the output may be the RSRP of the beams in a second set (e.g., the RSRP of the RS associated with all beams or the RSRP of the RS associated with set A of the beams). The RSRP of the beams in the first set may include the RSRP of the RS associated with some of all beams and / or the RSRP associated with set B of the beams. The RSRP of the beams in the second set may include the RSRP of the RS associated with all beams and / or the RSRP of the RS associated with set A of the beams.

[0194] Table 5 below summarizes the discussions and results related to beam performance improvement.

[0195] [Table 5]

[0196]

[0197] In the results, BM-Case1 refers to "the case of performing the estimation / prediction of the beams in set A based on the measurement results of the beams included in set B". Set A and set B are different.

[0198] Set A and set B related to the embodiments of the present disclosure described below can be defined based on Table 5 above. Set B may be a set of beams including the RS (RS received by the UE) transmitted by the base station. Set A may be a set of beams for estimating / determining beams based on the measurement results of the RS related to set B. Set A may be a set of beams for indicating a specific beam.

[0199] The purpose of BM-Case1 is to select / estimate / predict beams more precisely than selecting beams based on existing methods. Specifically, according to BM-Case1, the beams are selected / estimated / predicted based on set A, which is more precise than set B (e.g., in the selection, set A includes a larger number of beams than set B and has a beam shape with a narrower width than the width of the beams in set B).

[0200] The present disclosure presents the following scenario: Based on the ALI / ML model on the network (NW) side, the base station performs beam indication for set A based on beam measurements for set B and UE reporting results. Here, "beam indication for set A" means beam indication for a higher beam granularity (e.g., more beams, larger maximum / minimum beam angle difference, smaller inter-beam angle difference, etc.), and can be applied even when set A is not explicitly defined / set.

[0201] As an example, in the present disclosure, "set A" and "set B" are terms used to refer to the beam sets defined / configured for UE measurement / reporting. Thus, the beam sets defined / configured for beam indication for the base station can be referred to in different ways. In other words, the beam sets for beam indication for the base station can be configured separately from the beam sets for UE measurement / reporting. In the embodiments to be described below, the terms "set A" or "set B" are used in relation to beam indication, but these terms can mean that the beams indicated by the base station have the same characteristics as "set A" or "set B".

[0202] In the beam prediction operation based on the AI / ML model on the NW side, there may be situations where it is necessary to change, (re)train, or update the AI / ML model being applied due to changes in the UE's position, movement, or rotation. Whether to perform such an operation can be determined based on the following: i) UE reporting, ii) monitoring / measurement related to the beam / channel quality of the base station, iii) monitoring / measurement of the suitability of the environment in which the AI / ML model is applied, iv) the verification process of the AI / ML model (e.g., comparison with the ground truth), v) the amount / degree of change in the distribution of the model input / output data, etc. The UE's reporting can include at least one of a model change / update request, a beam quality value report, and / or a report on an event where the beam quality value drops to a predetermined threshold or less.

[0203] Table 6 below shows the items agreed upon in the RAN1#110bis meeting. The items agreed upon include content related to AI / ML model monitoring and lifecycle management (LCM).

[0204] [Table 6]

[0205]

[0206]

[0207] As described above, if the application of the AI / ML model must be temporarily suspended for model updates, fallback operations, etc., the base station must perform non-AI / ML-based beam indication. That is, the beam must be indicated based on set B. Hereinafter, the implementation manner of the beam indication performed in this case will be specifically examined.

[0208] Method 1

[0209] The base station configures / indicates to the UE whether the candidate beam set for performing beam indication is set B or set A.

[0210] The configuration / indication of the candidate beam set for performing beam indication can be performed based on RRC messages, MAC-CE, and / or DCI.

[0211] As an example, the message indicating the beam (e.g., the TCI / SRI field in DCI, the TCI activation MAC-CE, the PUCCH spatial relation MAC-CE) can include this information (as 1-bit information).

[0212] As an example, the candidate beam set change message (e.g., via MAC-CE) can be defined and configured / indicated separately from the beam indication message.

[0213] As an example, the configuration / indication can be a response message to a specific report / request from the UE. For example, the UE can monitor the quality of the beam indicated by the base station based on AI / ML prediction and report to the base station an event where the beam quality drops to a specific value or less. Based on the response message of the base station to the event occurrence report, it can be specified that the candidate beam set changes from set A to set B.

[0214] According to an embodiment, it can be assumed that set B is a subset of set A. Set B can also be represented as a reduced beam RS set. Whether to apply the reduced beam RS set can be configured / indicated.

[0215] For example, 64 CSI-RS resources (based on RRC signaling) can be configured to form a first set (e.g., set A). The 64 CSI-RS resources can be CSI-RS resources for beam management (BM).

[0216] The base station (or network) can configure / indicate to the UE i) whether to perform 6-bit beam indication based on the first set (e.g., set A) composed of 64 CSI-RS resources, or ii) whether to perform 4-bit beam indication based on the second set (e.g., set B) composed of some of the 64 CSI-RS resources (e.g., 16 CSI-RS resources). The information related to determining multiple sets / bits related to beam indication (e.g., 6-bit indication or 4-bit indication) can be included in the configuration / indication.

[0217] Some CSI-RS resources (e.g., the configuration for set B) can be determined / configured based on at least one of the following ① to ③.

[0218] ① Rules can be defined such that some CSI-RS resources are determined / configured as CSI-RS resources for the UE to perform beam measurement / reporting.

[0219] ② Some CSI-RS resources can be extracted from the set A beams (i.e., 64 CSI-RS resources) through specific (configured) rules.

[0220] As an example, some CSI-RS resources can consist of CSI-RS resources among the 64 CSI-RS resources having indices corresponding to modulo N. Specifically, assuming modulo 16, 16 CSI-RS resources having indices from 0 to 15 can be determined as some CSI-RS resources (set B).

[0221] As an example, some CSI-RS resources can consist of CSI-RS resources among the 64 CSI-RS resources having indices obtained by adding a specific offset value to the index corresponding to modulo N. Specifically, assuming modulo 16, 16 CSI-RS resources having indices from 10 to 25 can be determined as some CSI-RS resources (set B).

[0222] As an example, the N value and / or the offset value can be configured by the base station for the UE. As an example, the N value and / or the offset value can be pre-specified as specific values between the UE and the base station.

[0223] ③ The base station can specify (via a bitmap, etc.) to the UE the resources among the resources of set A (64 CSI-RS resources) that are to be included in set B.

[0224] According to an embodiment, it can be assumed that set B and set A are composed of different RSs. For example, set A can be composed of CSI-RS resources, and set B can be composed of SSB resources. The base station can configure / indicate to the UE the selection / switching information of the candidate beam RS set.

[0225] For example, 64 CSI-RS resources (based on RRC signaling) can be configured as the first set (e.g., set A), and 16 SSBs (or SSB resources) can be configured as the second set (e.g., set B).

[0226] The base station (or network) may configure / indicate to the UE i) whether to perform 6-bit beam indication based on the first set or ii) whether to perform 4-bit beam indication based on the second set. Information related to determining the set / number of bits associated with beam indication (e.g., 6-bit indication or 4-bit indication) may be included in the configuration / indication.

[0227] The configuration for the second set may be determined based on at least one of the following ① and ②.

[0228] ① Rules may be defined such that the second set consists of resources for the UE to perform beam measurement / reporting.

[0229] ② The base station may configure / indicate the second set (set B) (separately from set A) to the UE.

[0230] Method 1 may be used for AI / ML model retraining and fallback operations by (instantaneously) changing the candidate beam set.

[0231] Different from Method 1, a method may be considered where the candidate beam set is maintained as set A, but the relationship between set A and set B is used to perform set B beam indication. This is specifically described in Method 2 below.

[0232] Method 2

[0233] The base station may configure / indicate to the UE whether the beam indication is for set B or set A. The UE receiving the beam configuration / indication for set B may interpret the base station's beam indication based on the correlation information between set A beams and set B beams.

[0234] According to Method 2, the beam indication from the base station may be interpreted by the UE as follows.

[0235] For example, it may be assumed that 64 CSI-RS resources are configured as set A, and the UE receives beam indication based on a 6-bit indicator from the base station.

[0236] [1] The base station may configure / indicate to the UE the corresponding beam indication (6-bit indicator) for set A. The UE may interpret the 6-bit indicator as indicating one of 64 beams (one of 64 CSI-RS resources).

[0237] [2] The base station can configure / indicate to the UE the corresponding beam indication (6-bit indicator) for set B. The UE may not interpret the 6-bit indicator as indicating one of 64 beams. That is, the UE may interpret the 6-bit indicator as indicating one of 16 beams that have a mapping relationship with the 64 beams. As an example, 16 CSI-RS resources that have a mapping relationship with 64 CSI-RS resources can be defined / configured. As an example, 16 SSBs that have a mapping relationship with 64 CSI-RS resources can be defined / configured. As an example, 16 CSI-RS resources and SSBs that have a mapping relationship with 64 CSI-RS resources can be defined / configured.

[0238] Information for configuring / indicating whether the beam indication is for "set B or set A" can be configured / indicated to the UE based on RRC messages, MAC-CEs, and / or DCIs.

[0239] As an example, a message indicating a beam (e.g., the TCI / SRI field in DCI, the TCI activation MAC-CE, the PUCCH spatial relation MAC-CE) can include this information (as 1-bit information).

[0240] As an example, a candidate beam set change message (e.g., via MAC-CE) can be defined and configured / indicated separately from the beam indication message.

[0241] As an example, the configuration / indication can be a response message to a specific report / request from the UE. For example, the UE can monitor the quality of the beam indicated by the base station based on AI / ML prediction and report to the base station an event where the beam quality drops to a specific value or less. Based on the response message from the base station to the report of the event occurrence, it can be stipulated that the candidate beam set changes from set A to set B.

[0242] According to an embodiment, it can be assumed that set B is a subset of set A. In this case, information on the many-to-one correspondence relationship between the beams of set A and the beams of set B can be configured / indicated / stipulated.

[0243] As an example, the following rule can be configured / indicated / stipulated: 1 set B beam RS is mapped to N set A beam RSs in the order of the beam RS index. When this relationship is defined / configured and the base station configures a beam indication (for fallback, model update, etc.) based on set B, the UE interprets the beam indication from the base station as a beam indication for set B through the mapping information.

[0244] According to an embodiment, it can be assumed that set B and set A are composed of different RSs. For example, set A can be composed of CSI-RS resources and set B can be composed of SSB resources. At this time, the mapping relationship between the set A beams and the set B beams can be configured.

[0245] As an example, the implicit mapping relationship can be configured based on the QCL relationship information (e.g., QCL type D). As a specific example, when set B consists of SSB resources and set A consists of CSI-RS resources, the mapping relationship (association relationship) between the set A beam and the set B beam can be implicitly configured by the SSB resources having a QCL relationship with the CSI-RS resources. In other words, the SSB resources mapped to the CSI-RS resources can be the SSB resources having a QCL relationship with the corresponding CSI-RS resources.

[0246] When the base station provides the beam configuration / indication for set B to the UE and indicates a specific CSI-RS resource through this beam indication, the UE can interpret the beam indication as follows. Specifically, the UE can interpret the beam indication as the beam indication for the SSB resources having a QCL relationship with the specific CSI-RS resource.

[0247] When applying the above method, the beam set to which the proposed method is applied during the fallback or model update operation can be different from set B defined in the existing 3GPP RAN1 protocol.

[0248] In the existing protocol, the measurement beam set for estimating the beam based on set A (e.g., used as the input to the AI / ML model, for UE beam reporting for the NW-side model, and for beam measurement for the UE-side model) is defined as set B as described above. The difference between "set A" and "set B" used in the above method is not intended to limit the beam sets to which the embodiments defined in the present disclosure can be applied to those beam sets defined based on set A / set B.

[0249] In other words, a (separate) RS set different from the corresponding beam RS set (measurement beam set) can be defined / configured as the beam set for the proposed operation.

[0250] In addition, although the proposed method assumes a selection / change operation between two beam RS sets (set A and set B), the selection / change operation can be extended to a selection / change operation for three or more beam RS sets. In addition to the two beam RS sets, set C can also be defined / configured.

[0251] As an example, the base station can configure / indicate to the UE one set among set A, set B, and set C to be used / applied for the beam indication.

[0252] As an example, depending on a specific condition / situation, it can be specified which set among set B and set C to fallback to (or which set to apply).

[0253] As an example, i) the beam RS set to be used when the model is retrained / updated and ii) the beam RS set to be used when the model is turned off and the beam indication method falls back to traditional operation can be defined / configured separately. The beam RS set of i) above can be a beam RS set that is temporarily applied / used while a specific timer is running until the timer is completed. The beam RS set of ii) above can be a beam RS set that is continuously applied / used until there is a separate indication / configuration from the base station.

[0254] In the above embodiment, it is assumed and described that the beam indication based on set A is an indicator for the RS included in set A. However, this is only an example of the beam indication based on set A, and the set A beam indication can also be replaced with other forms of information other than the indication indicating a specific RS.

[0255] As an example, the beam of set A can be expressed based on a linear combination of the RS belonging to set B. The beam indication based on set A can include a plurality of RSs and the composite combination coefficients associated with the plurality of RSs.

[0256] As an example, the beam of set A can be represented by 2D / 3D coordinate values. The beam indication based on set A can include information regarding the coordinates associated with the beam of set A.

[0257] Although the proposed technology of the present disclosure is described based on NW AI / ML, this does not mean that the technology of the present disclosure can only be applied to the AI / ML implementation environment of NW, but the proposed technology can also be applied to the UE AI / ML implementation environment or the non-AI / ML implementation environment. In addition, another UE instead of the base station / NW can be applied, and it can also be applied to sidelink communication. In addition, it is mainly assumed that NW AI / ML performs training / inference based on the beam report of the UE, but this is not a limitation, and training / inference can also be performed for the NW AI / ML model through the uplink transmission of the UE and / or the reporting information of another UE (for example, CSI report, RRM report, etc.).

[0258] The "beam indication" in the present disclosure can include the indication of the PL RS in the case of the UL beam. That is, the operation of changing / configuring / indicating the candidate beam set to sets A and B can be linked to the operation of changing / configuring / indicating the candidate RS set for the PL RS (for example, separately configuring the PL RS set for set A and the PL RS set for set B).

[0259] In terms of implementation, the operations of the base station / UE according to the above embodiment (for example, the operations based on at least one of Methods 1 to 2) can be performed by the Figure 7 device described below (for example,Figure 7 are processed by processors 110 and 210 in

[0260] In addition, the operations of the base station / UE according to the above embodiments (e.g., operations based on at least one of Method 1 to Method 2) can be stored in a memory (e.g., Figure 7 140 and 240 in Figure 7 ) in the form of instructions / programs (e.g., instructions or executable code) for driving at least one processor (e.g.,

[0261] Hereinafter, a signaling process based on the above embodiments will be specifically described with reference to Figure 4 A signaling process according to an embodiment of the present disclosure is shown.

[0262] Figure 4

[0263] Figure 4 Figure 7 Figure 4 Figure 4 in Figure 4 This is for ease of description only and does not limit the scope of the present disclosure. In addition, some steps shown in may be omitted according to the situation and / or configuration. The base station belonging to

[0264] the NW in

[0265] The UE may receive the configuration related to set B (and set A) from the NW (S405). This configuration may include configuration information related to the TCI state, ID information for the UE beam, transmission period and time / frequency position information, sequence information, and / or information about the correlation between the RSs (e.g., whether there is QCL).

[0266] After the beam-related configuration (S405), the base station may send the RS belonging to set B (and set A) to the UE, and the UE may perform measurements on it (S410).

[0266] The UE that performs measurements on the beam-related configuration (S405) information and the set B beam may perform reporting of the corresponding measurement values (S415).

[0267] Based on the UE's reported information and / or another uplink signal / information, the NW (AI / ML) may perform beam prediction / selection and perform beam indication for the target channel / RS in set A (S420).

[0268] The NW or UE may perform monitoring (S425) of the AI / ML model and / or the associated beam / channel quality, and based on this, may perform an indication (S430) to change / select a beam set to set B by applying the techniques of the present disclosure. Based on this, beam indication may be performed in set B (S435).

[0269] When applying the operation, processes S430 and S435 may also occur simultaneously.

[0270] Assume that the beam indication based on set A is given a higher priority than the beam indication based on set B. Conversely, however, the beam indication based on set B may be given a priority and then the beam indication based on set A may also be applied when it is determined that the application of the AI / ML model is appropriate.

[0271] As described above, the above NW / UE signaling and operations may be implemented by Figure 7 the apparatuses 100 and 200 in. For example, the NW may correspond to the first apparatus 100, and the UE may correspond to the second apparatus 200, and in some cases, the opposite situation may also be considered.

[0272] For example, the above NW / UE signaling and operations may be processed by Figure 7 at least one of the processors 110 or 210, and the above NW / UE signaling and operations may be stored in the memory ( Figure 7 in 140 or 240) in the form of commands / programs (e.g., instructions, executable code) for driving at least one of the processors ( Figure 7 110 or 210 in).

[0273] Hereinafter, reference will be made to Figure 5 and Figure 6 to describe the above embodiments in detail from the perspective of the operations of the UE and the base station. The methods to be described below are only distinguished for ease of description, and it goes without saying that some components of any one method may be replaced by some components of another method, or they may be combined and applied to each other.

[0274] Figure 5 is a flowchart for describing a method performed by a UE in a wireless communication system according to an embodiment of the present disclosure.

[0275] Referring to Figure 5 , the method performed by a UE in a wireless communication system according to an embodiment of the present disclosure includes a configuration information receiving step S510, a beam indication receiving step S520, and a physical signal / channel receiving step S530.

[0276] In S510, the UE receives configuration information from the base station. The configuration information can be received via higher layer signaling (e.g., RRC signaling).

[0277] The configuration information may include information for a plurality of reference signals (RSs) used for beam indication. A plurality of RS sets can be configured based on the plurality of RSs. A plurality of RS sets can be configured based on Method 1 and / or Method 2. As an example, the plurality of RS sets may include a first RS set and a second RS set.

[0278] In S520, the UE receives beam indication from the base station.

[0279] As an example, the beam indication can be based on downlink control information (DCI) or medium access control (MAC) control element (CE). As an example, the beam indication can be based on the DCI that schedules a physical signal / channel (e.g., PDSCH).

[0280] According to an embodiment, beam indication can be performed based on one of the plurality of RS sets. The beam indication can be based on Method 1 or Method 2. This will be specifically described below.

[0281] As an example, the beam indication can be an indicator composed of a plurality of bits (6 bits) representing one of all RSs (e.g., 64 RSs), or an indicator composed of a plurality of bits (4 bits) representing one of some RSs (e.g., 16 RSs). At this time, the beam indication can also include a plurality of bit-related indicators. Specifically, the beam indication can include an indicator representing one of the first RS set and the second RS set. The number of bits related to the beam indication can be determined based on the indicator. This embodiment can be based on Method 1.

[0282] The number of bits related to the beam indication can be i) a first number of bits (e.g., 6) based on the number of RSs belonging to the first RS set or ii) a second number of bits (e.g., 4) based on the number of RSs belonging to the second RS set.

[0283] The first RS set can be composed of a plurality of RSs. The second RS set can be composed of some of the plurality of RSs. The second RS set can be configured / determined based on at least one of ① to ③ of Method 1.

[0284] As an example, the RSs belonging to the second RS set include the RSs for beam measurement among the plurality of RSs (e.g., ① of Method 1).

[0285] As an example, the RSs belonging to the second RS set may include the RSs determined based on criteria related to the RS index among multiple RSs (e.g., ② of Method 1). The RS based on a specific RS index can be determined based on criteria related to the RS index. The specific RS index can be determined based on the above modulo N and / or offset.

[0286] According to an embodiment, the first RS set may be composed of multiple RSs. The second RS set may be composed of the RSs mapped to the multiple RSs. This embodiment may be based on Method 2.

[0287] The beam indication may include an indicator having a number of bits based on the number of multiple RSs (e.g., a 6-bit indicator). The method of interpreting the indicator may vary depending on the RS set related to the beam indication. This will be specifically described below.

[0288] Based on the beam indication being related to the first RS set, the RS indicated by the indicator can be determined as the RS related to the physical signal / channel.

[0289] Based on the beam indication being related to the second RS set, the RSs mapped to the RS indicated by the indicator can be determined as the RSs related to the physical signal / channel.

[0290] As an example, the beam indication may be implicitly related to the first RS set or the second RS set. As a specific example, when the beam indication is based on a response to a report of the occurrence of an event related to the first RS set (or the second RS set), the beam indication can be specified as being related to the second RS set (or the first RS set).

[0291] As an example, the beam indication may further include an indicator indicating one of the first RS set and the second RS set.

[0292] The RSs belonging to the second RS set have a mapping relationship (N-to-1 mapping and / or QCL) with the RSs belonging to the first RS set.

[0293] As an example, each RS belonging to the second RS set may be mapped to two or more RSs among the multiple RSs. As a specific example, the first RS set may be composed of 64 RSs, and the second RS set may be composed of 16 RSs having a mapping relationship with the 64 RSs. In this case, each RS belonging to the second RS set may be mapped to four RSs belonging to the first RS set.

[0294] As an example, a quasi - co - location (QCL) relationship is configured between each RS belonging to the second RS set and two or more of the multiple RSs. As a specific example, the first RS set may consist of 64 RSs, and the second RS set may consist of 16 RSs having a QCL relationship with the 64 RSs. In this case, a QCL relationship can be configured between each RS belonging to the second RS set and four RSs belonging to the first RS set.

[0295] In S530, the UE receives a physical signal / channel from the base station based on a beam indication.

[0296] The physical signal / channel can be a physical downlink control channel (PDCCH), a physical downlink shared channel (PDSCH), or a channel state information reference signal (CSI - RS).

[0297] A beam (e.g., a spatial - domain reception filter) related to the physical signal / channel can be determined based on the beam indication. For example, based on the beam indication, an RS belonging to one of the multiple RS sets can be determined as the RS related to the physical signal / channel.

[0298] The above operations based on S510 to S530 can be implemented by Figure 7 the device in. For example, the UE 200 can control one or more transceivers 230 and / or one or more memories 240 to perform the operations based on S510 to S530.

[0299] Hereinafter, the above - described embodiments will be specifically described from the perspective of the operations of the base station.

[0300] S610 to S630 described below correspond to Figure 5 S510 to S530 described in. By considering the corresponding relationship, redundant descriptions are omitted. That is, the specific descriptions of the base - station operations described below can be replaced by the descriptions / embodiments corresponding to the corresponding operations. As an example, Figure 5 the descriptions / embodiments of S510 and S530 in can be additionally applied to the base - station operations of S610 to S630 described below. Figure 5

[0301] Figure 6 is a flowchart for describing a method performed by a base station according to another embodiment of the present disclosure.

[0302] Figure 6 Referring to a method performed by a base station in a wireless communication system according to another embodiment of the present disclosure includes a configuration - information sending step S610, a beam - indication sending step S620, and a physical - signal / channel sending step S630.

[0303] In S610, the base station sends configuration information to the UE.

[0304] In S620, the base station sends a beam indication to the UE.

[0305] In S630, the base station sends a physical signal / channel to the UE based on the beam indication.

[0306] The operations based on S610 to S630 above can be implemented by Figure 7 the device in. For example, the base station 100 can control one or more transceivers 130 and / or one or more memories 140 to perform the operations based on S610 to S630.

[0307] Next, refer to Figure 7 to describe the device to which the embodiments of the present disclosure are applicable (the device that implements the method / operation according to the embodiments of the present disclosure).

[0308] Figure 7 Illustrates the configurations of the first device and the second device according to the embodiments of the present disclosure.

[0309] The first device 100 may include a processor 110, an antenna unit 120, a transceiver 130, and a memory 140.

[0310] The processor 110 may perform signal processing related to the baseband and includes a high-layer processing unit 111 and a physical-layer processing unit 115. The high-layer processing unit 111 may process operations of the MAC layer, RRC layer, or higher layers. The physical-layer processing unit 115 may process operations of the PHY layer. For example, if the first device 100 is a base station (BS) device in BS-UE communication, the physical-layer processing unit 115 may perform uplink received signal processing, downlink transmitted signal processing, etc. For example, if the first device 100 is the first UE device in UE-to-UE communication, the physical-layer processing unit 115 may perform downlink received signal processing, uplink transmitted signal processing, sidelink transmitted signal processing, etc. In addition to performing signal processing related to the baseband, the processor 110 may also control the overall operation of the first device 100.

[0311] The antenna unit 120 may include one or more physical antennas, and if the antenna unit 120 includes multiple antennas, it supports MIMO transmission / reception. The transceiver 130 may include a radio frequency (RF) transmitter and an RF receiver. The memory 140 may store the information processed by the processor 110 and software, operating system, and applications related to the operation of the first device 100. The memory 140 may also include components such as buffers.

[0312] In the embodiments described in the present disclosure, the processor 110 of the first device 100 may be configured to implement the operations of the BS in BS-UE communication (or the operations of the first UE device in UE-to-UE communication).

[0313] The second device 200 may include a processor 210, an antenna unit 220, a transceiver 230, and a memory 240.

[0314] The processor 210 may perform signal processing related to the baseband and includes a high-layer processing unit 211 and a physical-layer processing unit 215. The high-layer processing unit 211 may handle operations of the MAC layer, RRC layer, or higher layers. The physical-layer processing unit 215 may handle operations of the PHY layer. For example, if the second device 200 is a UE device in BS-UE communication, the physical-layer processing unit 215 may perform downlink received signal processing, uplink transmitted signal processing, etc. For example, if the second device 200 is a second UE device in UE-to-UE communication, the physical-layer processing unit 215 may perform downlink received signal processing, uplink transmitted signal processing, sidelink received signal processing, etc. In addition to performing signal processing related to the baseband, the processor 210 may also control the overall operation of the second device 210.

[0315] The antenna unit 220 may include one or more physical antennas, and if the antenna unit 220 includes multiple antennas, it supports MIMO transmission / reception. The transceiver 230 may include an RF transmitter and an RF receiver. The memory 240 may store information processed by the processor 210 and software, operating systems, and applications related to the operation of the second device 200. The memory 240 may also include components such as buffers.

[0316] In the embodiments described in the present disclosure, the processor 210 of the second device 200 may be configured to implement the operations of the UE in BS-UE communication (or the operations of the second UE device in UE-to-UE communication).

[0317] The descriptions of the BS and UE in BS-UE communication (or the first UE device and the second UE device in UE-to-UE communication) in the examples of the present disclosure may be equivalently applied to the operations of the first device 100 and the second device 200, and redundant descriptions are omitted.

[0318] In addition to LTE, NR, and 6G, the wireless communication technologies implemented in the device 100 and the device 200 according to the present disclosure may also include NarrowBand Internet of Things (NB-IoT) for low-power communication. For example, the NB-IoT technology may be an example of a Low-Power Wide-Area Network (LPWAN) technology and may be implemented in standards such as LTE Cat NB1 and / or LTE Cat NB2. The NB-IoT technology is not limited to the above names.

[0319] Additionally or alternatively, the wireless communication technology implemented in apparatuses 100 and 200 according to the present disclosure may perform communication based on LTE-M technology. For example, LTE-M technology may be an example of LPWAN technology and may be referred to by various names such as enhanced machine type communication (eMTC). For example, LTE-M technology may be implemented with at least one of various standards such as 1) LTE CAT0, 2) LTE Cat M1, 3) LTE Cat M2, 4) LTE non-BL (non-bandwidth limited), 5) LTE-MTC, 6) LTE machine type communication, and / or 7) LTE M. LTE-M technology is not limited to the above names.

[0320] Additionally or alternatively, considering low-power communication, the wireless communication technology implemented in apparatuses 100 and 200 according to the present disclosure may include at least one of ZigBee, Bluetooth, and low power wide area network (LPWAN), and is not limited to the above names. For example, ZigBee technology may create a personal area network (PAN) related to small / low-power digital communication based on various standards such as IEEE 802.15.4 and may be referred to by various names.

Claims

1. A method performed by a user equipment UE in a wireless communication system, the method comprising the steps of: receiving configuration information, wherein the configuration information includes information for a plurality of reference signals RS for beam indication, and a plurality of RS sets are configured based on the plurality of RSs; receiving the beam indication; and receiving a physical signal / channel based on the beam indication, wherein the beam indication is performed based on one of the plurality of RS sets.

2. The method according to claim 1, wherein, the plurality of RS sets include a first RS set and a second RS set.

3. The method according to claim 2, wherein, the beam indication includes an indicator indicating one of the first RS set and the second RS set, wherein the number of bits associated with the beam indication is determined based on the indicator, and wherein the number of bits associated with the beam indication is i) a first number of bits based on the number of RSs belonging to the first RS set, or ii) a second number of bits based on the number of RSs belonging to the second RS set.

4. The method according to claim 2, wherein, the first RS set consists of the plurality of RSs, and the second RS set consists of some of the plurality of RSs.

5. The method according to claim 4, wherein, the RSs belonging to the second RS set include the RSs for beam measurement among the plurality of RSs.

6. The method according to claim 4, wherein, the RSs belonging to the second RS set include the RSs determined based on a criterion related to an RS index among the plurality of RSs.

7. The method according to claim 2, wherein, the first RS set consists of the plurality of RSs, and the second RS set consists of the RSs mapped to the plurality of RSs.

8. The method according to claim 7, wherein, the beam indication includes an indicator having a number of bits based on the number of the plurality of RSs, wherein, based on the beam indication being related to the first RS set, the RS indicated by the indicator is determined as the RS related to the physical signal / channel, and wherein, based on the beam indication being related to the second RS set, the RS mapped to the RS indicated by the indicator is determined as the RS related to the physical signal / channel.

9. The method according to claim 7, wherein, each RS belonging to the second RS set is mapped to two or more of the plurality of RSs.

10. The method according to claim 7, wherein, a quasi-co-location QCL relationship is configured between each RS belonging to the second RS set and two or more of the plurality of RSs.

11. A user equipment UE operating in a wireless communication system, the UE comprising: one or more transceivers; one or more processors; and one or more memories connected to the one or more processors and storing instructions, Wherein, based on the instructions being executed by the one or more processors, the one or more processors are configured to perform all steps of the method according to any one of claims 1 to 10.

12. An apparatus, the apparatus comprising: one or more memories, and one or more processors functionally connected to the one or more memories, wherein the one or more memories store instructions, and based on the instructions being executed by the one or more processors, the one or more processors are configured to perform all steps of the method according to any one of claims 1 to 10.

13. One or more non-transitory computer-readable media storing instructions, wherein the instructions executable by one or more processors configure the one or more processors to perform all steps of the method according to any one of claims 1 to 10.

14. A method performed by a base station in a wireless communication system, the method comprising the steps of: sending configuration information, wherein the configuration information includes information for a plurality of reference signals RS for beam indication, and a plurality of RS sets are configured based on the plurality of RSs; sending the beam indication; and sending a physical signal / channel based on the beam indication, wherein the beam indication is performed based on one of the plurality of RS sets.

15. A base station operating in a wireless communication system, the base station comprising: one or more transceivers; one or more processors; and one or more memories connected to the one or more processors and storing instructions, wherein, based on the instructions being executed by the one or more processors, the one or more processors are configured to perform all steps of the method according to claim 14.

Images