WO2025134328A1 - Terminal, wireless communication method, and base station - Google Patents

Abstract

A terminal according to an aspect disclosed herein is characterized by comprising: a reception unit that receives a setting related to a codebook for channel state information (CSI) reporting; and a control unit that, on the basis of the setting, determines the value of a parameter for an enhanced type 2 codebook for CSI reporting, the enhanced type 2 codebook being for a rank or level higher than 4. According to one aspect disclosed herein, appropriate CSI feedback can be achieved.

Description

Terminal, wireless communication method and base station

This disclosure relates to terminals, wireless communication methods, and base stations in next-generation mobile communication systems.

Long Term Evolution (LTE) was specified for Universal Mobile Telecommunications System (UMTS) networks with the aim of achieving higher data rates and lower latency (Non-Patent Document 1). In addition, LTE-Advanced (3GPP Rel. 10-14) was specified for the purpose of achieving higher capacity and greater sophistication over LTE (Third Generation Partnership Project (3GPP (registered trademark)) Release (Rel.) 8, 9).

Successor systems to LTE (e.g., 5th generation mobile communication system (5G), 5G+ (plus), 6th generation mobile communication system (6G), New Radio (NR), 3GPP Rel. 15 and later, etc.) are also under consideration.

3GPP TS 36.300 V8.12.0 “Evolved Universal Terrestrial Radio Access (E-UTRA) and Evolved Univers al　Terrestrial　Radio　Access　Network　(E-UTRAN);　Overall　description;　Stage 2　(Release　8)”, April 2010

In future wireless communication systems, for example, CSI compression will be performed in Artificial Intelligence (AI)/Machine Learning (ML)-based Channel State Information (CSI) feedback. In CSI compression and feedback, it is preferable for the UE to report high-precision CSI (ground-truth CSI) to the NW for at least one of data collection and performance monitoring on the NW side. To report ground-truth CSI, it is possible to apply high-precision CSI feedback (e.g., CSI with enhanced type 2 or enhanced type 2 port selection codebook applied).

However, the method for reporting high-precision CSI when CSI compression is performed is not clear. For example, it is not clear how to determine parameters for an extended Type 2 codebook for ranks or layers greater than 4. If the method for determining these parameters is not made clear, there is a risk that high-precision CSI used for comparison with compressed CSI cannot be properly transmitted, and proper CSI feedback using AI cannot be achieved.

Therefore, one of the objectives of this disclosure is to provide a terminal, a wireless communication method, and a base station that can realize appropriate CSI feedback.

A terminal according to one embodiment of the present disclosure is characterized in that it has a receiving unit that receives settings related to a codebook for channel state information (CSI) reporting, and a control unit that determines parameter values for an extended type 2 codebook for ranks or layers greater than 4 for CSI reporting based on the settings.

According to one aspect of the present disclosure, appropriate CSI feedback can be achieved.

FIG. 1 is a diagram illustrating an example of a framework for managing AI models. FIG. 2 is a diagram showing an example of CSI feedback using an encoder/decoder. 3A, 3B and 3C are diagrams showing the contents of parts 1 and 2 in each type of CSI feedback. 4 is a diagram showing a codebook parameter setting table in Rel. FIG. 5 shows a codebook for 1-layer, 2-layer, 3-layer, and 4-layer CSI reporting using antenna ports 3000 to 2999+P _CSI-RS. FIG. 6 is a diagram showing an example of a new codebook parameter setting table. 7A to 7D are diagrams showing examples of maximum values of the total number of NZCs. FIG. 8 is a diagram showing a codebook parameter setting table in the first embodiment. 9A and 9B are diagrams illustrating examples of codebook parameters according to the second embodiment. FIG. 10 illustrates a codebook for 1-layer, 2-layer, 3-layer, and 4-layer CSI reporting using antenna ports 3000 to 2999+P _CSI-RS in an extended Type II port selection codebook. FIG. 11 is a diagram illustrating an example of a schematic configuration of a wireless communication system according to an embodiment. FIG. 12 is a diagram illustrating an example of the configuration of a base station according to an embodiment. FIG. 13 is a diagram illustrating an example of the configuration of a user terminal according to an embodiment. FIG. 14 is a diagram illustrating an example of the hardware configuration of a base station and a user terminal according to an embodiment. FIG. 15 is a diagram illustrating an example of a vehicle according to an embodiment.

(CSI report or reporting)
In NR, a terminal (also referred to as a user terminal, User Equipment (UE), etc.) generates (also referred to as determining, calculating, estimating, measuring, etc.) channel state information (CSI) based on a reference signal (RS) (or a resource for the RS), and transmits (also referred to as reporting, feedback, etc.) the generated CSI to a network (e.g., a base station). The CSI may be transmitted to the base station, for example, using an uplink control channel (e.g., a Physical Uplink Control Channel (PUCCH)) or an uplink shared channel (e.g., a Physical Uplink Shared Channel (PUSCH)).

The RS used to generate the CSI may be, for example, at least one of a Channel State Information Reference Signal (CSI-RS), a Synchronization Signal/Physical Broadcast Channel (SS/PBCH) block, a Synchronization Signal (SS), a DeModulation Reference Signal (DMRS), etc.

The CSI-RS may include at least one of a Non-Zero Power (NZP) CSI-RS and a CSI-Interference Management (CSI-IM). The SS/PBCH block is a block including an SS and a PBCH (and corresponding DMRS), and may be referred to as an SS block (SSB), etc. The SS may also include at least one of a Primary Synchronization Signal (PSS) and a Secondary Synchronization Signal (SSS).

CSI is a channel quality indicator (CQI), a precoding matrix indicator (PMI), a CSI-RS resource indicator (CSI-RS Resource Indicator (CRI)), a SS/PBCH block resource indicator (SSBRI), and a layer indicator (Layer Indicator (LAI)). The L1-RSRP may include at least one of the following: L1-Level Indicator (LI), Rank Indicator (RI), L1-RSRP (Layer 1 Reference Signal Received Power), L1-RSRQ (Reference Signal Received Quality), L1-SINR (Signal to Interference plus Noise Ratio), and L1-SNR (Signal to Noise Ratio).

The UE may receive information regarding CSI reporting (report configuration information) and control CSI reporting based on the report configuration information. The report configuration information may be, for example, "CSI-ReportConfig" of the information element (IE) of Radio Resource Control (RRC). Note that in this disclosure, RRC IE may be interchangeably read as RRC parameters, higher layer parameters, etc.

The reporting configuration information (e.g., the RRC IE "CSI-ReportConfig") may include, for example, at least one of the following:
Information regarding the type of CSI report (report type information, e.g., RRC IE "reportConfigType")
Information on one or more quantities of CSI to be reported (one or more CSI parameters) (report quantity information, e.g., RRC IE “reportQuantity”)
Information on the RS resource used to generate the amount (the CSI parameter) (resource information, for example, “CSI-ResourceConfigId” of the RRC IE)
Information on the frequency domain to which the CSI is reported (frequency domain information, for example, the RRC IE "reportFreqConfiguration")

For example, the report type information may indicate a periodic CSI (Periodic CSI (P-CSI)) report, an aperiodic CSI (A-CSI) report, or a semi-persistent CSI (Semi-Persistent CSI (SP-CSI)) report.

The reporting amount information may also specify a combination of at least one of the above CSI parameters (e.g., CRI, RI, PMI, CQI, LI, L1-RSRP, etc.).

The resource information may also be an ID of a resource for the RS. The resource for the RS may include, for example, a non-zero power CSI-RS resource or SSB, and a CSI-IM resource (for example, a zero power CSI-RS resource).

The frequency domain information may also indicate the frequency granularity of the CSI reporting. The frequency granularity may include, for example, a wideband and a subband. The wideband is the entire CSI reporting band. The wideband may be, for example, the entirety of a certain carrier (Component Carrier (CC)), cell, serving cell), or the entirety of a bandwidth part (BWP) within a certain carrier. The wideband may also be rephrased as the CSI reporting band, the entire CSI reporting band, etc.

Furthermore, a subband may be a part of a wideband and may be composed of one or more resource blocks (RBs or PRBs). The size of the subband may be determined according to the size of the BWP (number of PRBs).

The frequency domain information may indicate whether wideband or subband PMI is to be reported (the frequency domain information may include, for example, the RRC IE "pmi-FormatIndicator" used to determine whether wideband PMI reporting or subband PMI reporting is to be performed). The UE may determine the frequency granularity of the CSI report (i.e., whether wideband PMI reporting or subband PMI reporting) based on at least one of the above reporting amount information and frequency domain information.

When wideband PMI reporting is configured (determined), one wideband PMI may be reported for the entire CSI reporting band. On the other hand, when subband PMI reporting is configured, a single wideband indication i1 may be reported for the entire CSI reporting band, and one subband indication i2 (e.g., one subband indication for each subband) may be reported for each of one or more subbands within the entire CSI reporting band.

The UE performs channel estimation using the received RS and estimates the channel matrix H. The UE feeds back an index (PMI) that is determined based on the estimated channel matrix.

The PMI may indicate a precoder matrix (also referred to simply as a precoder) that the UE considers appropriate to use for downlink (DL) transmissions to the UE. Each value of the PMI may correspond to one precoder matrix. A set of PMI values may correspond to a set of different precoder matrices, called a precoder codebook (also referred to simply as a codebook).

In the space domain, the CSI report may include one or more types of CSI. For example, the CSI may include at least one of a first type (Type 1 CSI) used for selecting a single beam and a second type (Type 2 CSI) used for selecting multiple beams. A single beam may be rephrased as a single layer, and multiple beams may be rephrased as multiple beams. In addition, Type 1 CSI does not assume multi-user multiple input multiple output (MIMO), and Type 2 CSI may assume multi-user MIMO.

The codebook may include a codebook for type 1 CSI (also called a type 1 codebook, etc.) and a codebook for type 2 CSI (also called a type 2 codebook, etc.). Type 1 CSI may also include type 1 single-panel CSI and type 1 multi-panel CSI, and different codebooks (type 1 single-panel codebook, type 1 multi-panel codebook) may be defined for each.

In this disclosure, Type 1 and Type I may be interpreted as interchangeable. In this disclosure, Type 2 and Type II may be interpreted as interchangeable.

The uplink control information (UCI) type may include at least one of the following: Hybrid Automatic Repeat reQuest ACKnowledgement (HARQ-ACK), scheduling request (SR), and CSI. The UCI may be carried by the PUCCH or the PUSCH.

In Rel. 15 NR, UCI may contain one CSI part for wideband PMI feedback. CSI report #n contains PMI wideband information if reported.

In Rel. 15 NR, UCI can contain two CSI parts for subband PMI feedback. CSI part 1 contains wideband PMI information. CSI part 2 contains one wideband PMI information and some subband PMI information. CSI part 1 and CSI part 2 are coded separately.

(Application of Artificial Intelligence (AI)) Technology to Wireless Communications)
Regarding future wireless communication technologies, the use of AI technologies such as machine learning (ML) for network/device control and management is being considered.

For example, it is being considered that terminals (user equipment (UE))/base stations (BS)) will utilize AI technology to improve channel state information (CSI) feedback (e.g., reducing overhead, improving accuracy, prediction), improve beam management (e.g., improving accuracy, prediction in the time/space domain), and improve position measurement (e.g., improving position estimation/prediction).

The AI model may output at least one piece of information such as an estimate, a prediction, a selected action, a classification, etc. based on the input information. The UE/BS may input channel state information, reference signal measurements, etc. to the AI model, and output highly accurate channel state information/measurements/beam selection/position, future channel state information/radio link quality, etc.

In this disclosure, AI may be interpreted as an object (also called a target, object, data, function, program, etc.) having (implementing) at least one of the following characteristics:
- Estimation based on observed or collected information;
- making choices based on observed or collected information;
- Predictions based on observed or collected information.

In this disclosure, estimation, prediction, and inference may be interpreted as interchangeable. Also, in this disclosure, estimate, predict, and infer may be interpreted as interchangeable.

In the present disclosure, an object may be, for example, an apparatus such as a UE or a BS, or a device. Also, in the present disclosure, an object may correspond to a program/model/entity that operates in the apparatus.

In addition, in the present disclosure, an AI model may be interpreted as an object having (implementing) at least one of the following characteristics:
- Producing estimates by feeding information,
- Predicting estimates by providing information
- Discover features by providing information,
- Select an action by providing information.

In addition, in this disclosure, an AI model may refer to a data-driven algorithm that applies AI techniques to generate a set of outputs based on a set of inputs.

Furthermore, in this disclosure, AI model, model, ML model, predictive analytics, predictive analysis model, tool, autoencoder, encoder, decoder, neural network model, AI algorithm, scheme, etc. may be interchangeable. Furthermore, the AI model may be derived using at least one of regression analysis (e.g., linear regression analysis, multiple regression analysis, logistic regression analysis), support vector machine, random forest, neural network, deep learning, etc.

In this disclosure, the term "autoencoder" may be interchangeably referred to as any autoencoder, such as a stacked autoencoder or a convolutional autoencoder. The encoder/decoder of this disclosure may employ models such as Residual Network (ResNet), DenseNet, and RefineNet.

Furthermore, in this disclosure, encoder, encoding, encoding/encoded, modification/alteration/control by an encoder, compressing, compress/compressed, generating, generate/generated, etc. may be read as interchangeable terms.

Furthermore, in this disclosure, the terms decoder, decoding, decode/decoded, modification/alteration/control by a decoder, decompressing, decompress/decompressed, reconstructing, reconstruct/reconstructed, etc. may be interpreted as interchangeable.

In the present disclosure, a layer (of an AI model) may be interpreted as a layer (input layer, intermediate layer, etc.) used in an AI model. A layer in the present disclosure may correspond to at least one of an input layer, intermediate layer, output layer, batch normalization layer, convolution layer, activation layer, dense layer, normalization layer, pooling layer, attention layer, dropout layer, fully connected layer, etc.

In this disclosure, methods for training an AI model may include supervised learning, unsupervised learning, reinforcement learning, federated learning, and the like. Supervised learning may refer to the process of training a model from inputs and corresponding labels. Unsupervised learning may refer to the process of training a model without labeled data. Reinforcement learning may refer to the process of training a model from inputs (i.e., states) and feedback signals (i.e., rewards) resulting from the model's outputs (i.e., actions) in the environment with which the model interacts.

In this disclosure, terms such as generate, calculate, derive, etc. may be interchangeable. In this disclosure, terms such as implement, operate, operate, execute, etc. may be interchangeable. In this disclosure, terms such as train, learn, update, retrain, etc. may be interchangeable. In this disclosure, terms such as infer, after-training, production use, actual use, etc. may be interchangeable. In this disclosure, terms such as signal and signal/channel may be interchangeable.

Figure 1 shows an example of a framework for managing an AI model. In this example, each stage related to the AI model is shown as a block. This example is also expressed as life cycle management of an AI model.

The data collection stage corresponds to the stage of collecting data for generating/updating an AI model. The data collection stage may include data organization (e.g., determining which data to transfer for model training/model inference), data transfer (e.g., transferring data to an entity (e.g., UE, gNB) that performs model training/model inference), etc.

Note that data collection may refer to a process in which data is collected by a network node, management entity, or UE for the purpose of AI model training/data analysis/inference. In this disclosure, the terms process and procedure may be interchangeable.

In the model training stage, model training is performed based on the data (training data) transferred from the collection stage. This stage may include data preparation (e.g., performing data preprocessing, cleaning, formatting, conversion, etc.), model training/validation, model testing (e.g., checking whether the trained model meets performance thresholds), model exchange (e.g., transferring the model for distributed learning), model deployment/update (deploying/updating the model to the entities that will perform model inference), etc.

In addition, AI model training may refer to a process for training an AI model in a data-driven manner and obtaining a trained AI model for inference.

Also, AI model validation may refer to a sub-process of training to evaluate the quality of an AI model using a dataset different from the dataset used to train the model. This sub-process helps select model parameters that generalize beyond the dataset used to train the model.

Also, AI model testing may refer to a sub-process of training to evaluate the performance of the final AI model using a dataset different from the dataset used for model training/validation. Note that testing, unlike validation, does not necessarily require subsequent model tuning.

In the model inference stage, model inference is performed based on the data (inference data) transferred from the collection stage. This stage may include data preparation (e.g., performing data preprocessing, cleaning, formatting, transformation, etc.), model inference, model monitoring (e.g., monitoring the performance of model inference), model performance feedback (feeding back model performance to the entity performing the model training), output (providing model output to the actor), etc.

In addition, AI model inference may refer to the process of using a trained AI model to produce a set of outputs from a set of inputs.

Also, a UE side model may refer to an AI model whose inference is performed entirely in the UE. A network side model may refer to an AI model whose inference is performed entirely in the network (e.g., gNB).

Also, a one-sided model may refer to a UE-side model or a network-side model. A two-sided model may refer to a pair of AI models where joint inference is performed. Here, joint inference may include AI inference where the inference is performed jointly across the UE and the network, e.g., a first part of the inference may be performed first by the UE and the remaining part by the gNB (or vice versa).

Also, AI model monitoring may refer to the process of monitoring the inference performance of an AI model, and may be interchangeably read as model performance monitoring, performance monitoring, etc.

Note that model registration may refer to making a model executable through assigning a version identifier to the model and compiling it into the specific hardware used in the inference phase. Model deployment may refer to distributing (or activating at) a fully developed and tested run-time image (or image of the execution environment) of the model to the target (e.g., UE/gNB) where inference will be performed.

Actor stages may include action triggers (e.g., deciding whether to trigger an action on another entity), feedback (e.g., feeding back information needed for training data/inference data/performance feedback), etc.

Note that, for example, training of a model for mobility optimization may be performed in, for example, Operation, Administration and Maintenance (Management) (OAM) in a network (NW)/gNodeB (gNB). In the former case, interoperability, large capacity storage, operator manageability, and model flexibility (feature engineering, etc.) are advantageous. In the latter case, the latency of model updates and the absence of data exchange for model deployment are advantageous. Inference of the above model may be performed in, for example, a gNB.

Depending on the use case (i.e., the function of the AI model), the entity performing the training/inference may be different. The function of the AI model may include beam management, beam prediction, autoencoder (or information compression), CSI feedback, positioning, etc.

For example, for AI-assisted beam management based on measurement reports, the OAM/gNB may perform model training and the gNB may perform model inference.

For AI-assisted UE-assisted positioning, a Location Management Function (LMF) may perform model training and the LMF may perform model inference.

For CSI feedback/channel estimation using autoencoders, the OAM/gNB/UE may perform model training and the gNB/UE may perform model inference (jointly).

For AI-assisted beam management or AI-assisted UE-based positioning based on beam measurements, the OAM/gNB/UE may perform model training and the UE may perform model inference.

Note that model activation may mean activating an AI model for a particular function. Model deactivation may mean disabling an AI model for a particular function. Model switching may mean deactivating a currently active AI model for a particular function and activating a different AI model.

Model transfer may also refer to distributing an AI model over the air interface. This may include distributing either or both of the parameters of the model structure already known at the receiving end, or a new model with the parameters. This may also include a complete model or a partial model. Model download may refer to model transfer from the network to the UE. Model upload may refer to model transfer from the UE to the network.

(AI-based CSI feedback)
As a use case of utilizing an AI model, CSI compression using a two-sided AI model is being considered. Such a CSI compression method may be called AI-based CSI feedback, and may be realized, for example, by using an autoencoder.

Figure 2 shows an example of CSI feedback using an encoder/decoder. The UE transmits information (CSI feedback information) including encoded bits that are output by inputting CSI to an encoder from an antenna. The BS inputs the received CSI feedback information bits to a corresponding decoder to obtain the CSI to be output.

The input CSI may include, for example, information on channel coefficients (elements of a channel matrix) or information on precoding coefficients (elements of a precoding matrix). In other words, the CSI may correspond to information on the channel state in the space-frequency domain. Note that the input may include information other than CSI.

The CSI output from the decoder may be reconstructed CSI that corresponds to the input to the encoder, or it may be CSI different from the input to the encoder (e.g., if the input information is information on channel coefficients, it may be information on precoding coefficients, etc.).

In addition, the encoder/decoder may also include pre-processing of the input and post-processing of the output.

The encoded bits are more compressed than the input information before encoding, which is expected to reduce the communication overhead required for CSI feedback.

In this case, it is desirable to select and adjust the AI/ML so that the CSI acquired by the NW (base station) is close to the target CSI. The target CSI may be called the calculated CSI based on UE measurements, the ideal CSI (simulated CSI, fixed value), the actual CSI, or the ground truth CSI.

(2-part CSI report)
For PUSCH Type I, Type II, Extended Type II, and further Extended Type II port selection feedback, the CSI report consists of two parts:
Part 1: A fixed payload size applies. Contains the information necessary to derive the payload size in Part 2.
Part 2: Variable payload sizes are applied.

FIG. 3A is a diagram showing the contents of parts 1 and 2 in Type ICSI feedback. FIG. 3B is a diagram showing the contents of parts 1 and 2 in Type II CSI feedback. FIG. 3C is a diagram showing the contents of parts 1 and 2 in Extended Type II/Extended Type II Port Selection CSI feedback.

(Codebook settings)
The UE is configured with parameters related to the codebook (CodebookConfig) by higher layer signaling (RRC signaling) (FIG. 1). The codebook configuration is included in the CSI report configuration (CSI-ReportConfig) of the higher layer (RRC) parameters.

In the codebook setting, at least one codebook is selected from type 1 single panel (typeI-SinglePanel), type 1 multi-panel (typeI-MultiPanel), type 2 (typeII), and type 2 port selection (typeII-PortSelection).

The codebook parameters include parameters related to the codebook subset restriction (CBSR). The CBSR setting is a bit that indicates which PMI reports are allowed ('1') and which are not allowed ('0') for the precoder associated with the CBSR bit. One bit in the CBSR bitmap corresponds to one codebook index/antenna port.

(Type 2 Codebook)
Assuming ideal backhaul, synchronization, and the same number of antenna ports across multiple TRPs, CSI acquisition for coherent joint transmission (CJT) for FR1 and up to four TRPs is considered. For CJT multi-TRP for FDD, an improvement of the Rel. 16/17 type-2 codebook is considered.

Type 2 CSI feedback on PUSCH in Rel. 16 includes two parts. CSI Part 1 has a fixed payload size and is used to identify the number of information bits in CSI Part 2. The size of Part 2 is variable (UCI size depends on the number of non-zero amplitude coefficients (NZC), which is unknown to the base station). The UE reports the number of NZCs in CSI Part 1, which determines the size of CSI Part 2. The base station knows the size of CSI Part 2 after receiving CSI Part 1.

In enhanced Type-2 CSI feedback, CSI Part 1 includes RI, CQI, and an indication of the total number of non-zero amplitudes across layers for enhanced Type-2 CSI. The fields of Part 1 are coded separately. CSI Part 2 includes PMI for enhanced Type-2 CSI. Parts 1 and 2 are coded separately. CSI Part 2 (PMI) includes at least one of the following: oversampling factor, index of 2D-DFT basis, index M _initial of initial DFT basis (start offset) of selected DFT window, selected DFT basis per layer, non-zero LC coefficients (NZC, amplitude and phase) per layer, strongest coefficient indicator (SCI) per layer, and strongest coefficient amplitude per layer/polarization.

Fig. 4 is a diagram showing a codebook parameter setting table in Rel. 16. Fig. 4 shows the values of parameters L, _Pv , β corresponding to paramCombination-r16 in CodebookConfig-r16. In the type-2 codebook of Rel. 16, the payload size is determined by ( _N1 , _N2 , _O1 , _O2 , L, _pv , β), (Nsb, R). In the example of Fig. 4, in the case of paramCombination-r16=7,8, _Pv is not set when v∈{3,4} (when rank/layer is greater than 2).

(CSI Reconstruction Accuracy Performance)
In conventional Rel. 16 CSI feedback, the index of the discrete Fourier transform (DFT) vector in the spatial domain (SD) and the frequency domain (FD), the channel coefficient which is the quantized non-zero coefficient (NZC), is reported for the reconstruction of the channel information. The accuracy performance of the CSI reconstruction is related to the following (1) to (3).

(1) The number of indices of SD and FD DFT vectors, the number of NZCs, and the quantization level. These values are set by the base station (gNB) via the RRC parameter (CodebookConfig-r16), and the total payload is determined.
(2) Selection of DFT vector and NZC configured by RRC. These are selected by the UE implementation.
(3) Construction of basis vectors. The basis vectors may be model-based and fixed across all scenarios. Model-based basis vectors may be generated by conventional methods other than the AI/ML model of the data base. The UE and the base station (gNB) may have a common understanding of the basis vectors.

Enhanced Type 2 CSI Feedback
As shown in FIG. 4, the existing enhanced type 2 CSI feedback provides high-precision CSI feedback when paramCombination-r16 is 7 or 8, but does not support multi-layer CSI (rank>1) feedback with RI restriction parameters required for ground truth CSI feedback. Specifically, the UE does not expect that the higher layer parameter typeII-RI-Restriction-r16 is set to r _i =1 for any i>1 when paramCombination-r16 is equal to 7 or 8. If r _i is zero, the PMI and RI reports cannot correspond to any precoder associated with the v=i+1 layer. Note that the UE can determine and report RI=v when i=v. However, if paramCombination-r16 is 7 or 8, the UE cannot report RI>1.

If the UE applies paramCombination-r16=7 or 8 for v>2, an extension is required to inform the UE how to generate the PMI using the extended Type II codebook.

For a certain layer number v, implementation examples of PMI generation for the extended type II codebook of Rel. 16 are shown in (1) to (4) below. (2-1) and (2-2) may be executed in parallel. The parameters L, v, P _v , and β in the codebook parameter setting table are parameters for setting detailed PMI generation and its overhead.

(1) The UE selects a layer number v, or performs the following steps for each candidate value of v:
(2-1) The UE selects L Kronecker-based DFT vectors (beams) for spatial domain combining.
(2-2) The UE selects M _v ceil(p _v N ₃ /R) DFT vectors for frequency domain combining.
(3) The UE selects the combining coefficients, which are controlled by β.
(4) The UE normalizes and quantizes the amplitude and phase of the selected coefficients.

Note that the parameter R is set by the higher layer parameter numberOfPMI-SubbandsPerCQI-Subband, which controls the total number _N3 of precoding matrices indicated by the PMI as a function of the number of configured subbands of the csi-ReportingBand.

(Rel. 15 CSI and Grouping)
For Type I and Type II (e.g., Rel. 15) CSI codebooks, _i1 is wideband (WB) CSI and _i2 is subband (SB) CSI. The priority of the report is determined by WB or SB. In the following explanations of each equation, the explanation of parameters with the same meaning may be omitted.

Equation (1) denotes _i1 for Type-I single panel codebook. _i1,1 denotes the spatial domain (SD) vector index of layer 1 in one dimension. _i1,2 denotes the SD vector index of layer 1 in two dimensions. _i1,3 denotes the SD vector offset/phase offset of higher layers. For CSI-RS ports < 16, _i1,3 denotes the offset of SD vectors between layers. For CSI-RS ports ≥ 16, _i1,3 denotes the phase shift component of SD vectors between layers (same phase shift between layers). For Type-I single panel, _i2 denotes the subband phase of different polarizations and layers.

Equation (2) shows that _i1 of the Type I multi-panel codebook. _i1,4 indicates the in-phase between panels. In Type I multi-panel, _i2 indicates the subband phase of different polarizations and layers.

Equation (3) denotes _i1 , _i2 of the Type II codebook. _i1,1 denotes the selected oversampling coefficient. _i1,2 denotes the selected SD vector. _i1,3,l denotes the index of the strongest coefficient in each layer l. _i1,4,l denotes the coefficient WB amplitude in each layer l. _i2,1,l denotes the SB phase in each layer l. _i2,2,l denotes the SB amplitude in each layer l.

Equation (4) shows i ₁ and i ₂ of the type-II port selection codebook, where i _1,1 indicates the selected CSI-RS port, and the rest are the same as the elements of the type-II codebook.

(Rel. 16 CSI and Grouping)
The Rel. 16 extended type II/extended type II port selection codebook will be described. Equation (5) shows _i1 , _i2 of the extended type II codebook of Rel. 16. _i1,1 and _i1,2 are the same as the type II codebook. _i1,5 is the initial value of M (frequency domain starting position). _i1,6,l is the selected frequency domain vector of each layer l. _i1,7,l is the bitmap of the reported coefficients of each layer l. _i1,8,l is the strongest coefficient of each layer l. _i2,3,l is the layer and polarization specific amplitude. _i2,4,l is the amplitude of the coefficients per layer. _i2,5,l is the phase of the coefficients of each layer.

Equation (6) shows _i1 and _i2 of the extended type-II port selection codebook of Rel. _{16. i1,1} indicates the CSI-RS port selected as the type-II port selection codebook. The other parameters have the same meaning as the parameters of the extended type-II.

The Rel. 16 enhanced Type II PMIs are divided into three groups with different reporting priorities (eg, groups 0-2 below).
Group 0: i _1,1 , i _1,2 , i _1,8,l
Group 1: _i1,5 , i1,6 _,l , high priority part _i1,7 , _l , _i2,3,l , high priority part _i2,4,l , high priority part _i2,5,l
Group 2: Low priority part (i _1,7,l , i _2,4,l , i _2,5,l )

Each reported element ( _i1,7,l , _i2,4,l , _i2,5,l ) is associated with a priority value pri(l,i,f) based on the layer index, spatial domain and frequency domain vector index. l,i,f are the layer index, spatial beam index and frequency domain vector index, respectively. For layer and beam indices, smaller indices have higher priority. For frequency domain vectors, those with lower frequency components have higher priority. For the three domains, the priority is generally frequency domain > beam > layer.

(Definition of Extended Type II Codebook for Rel. 16)
5 is a diagram showing a codebook for 1-layer, 2-layer, 3-layer, and 4-layer CSI reporting using antenna ports 3000 to 2999+P _CSI-RS in the extended type-II codebook. W _l in FIG. 5 is expressed as follows:
W _l =W ₁ W~ _2,l W _f,l ^H

where the selected W _f,l contains the FD vector, and W~ _2,l is a reduced-dimensional representation of the PMI in the wavenumber (angle)-delay domain, where W~ means W with a superscript bar.

(New codebook parameter setting table)
Fig. 6 is a diagram showing an example of a new codebook parameter setting table. The example shown in Fig. 6 differs from the table in Fig. 4 in that the value of _Pv is defined when paramCombination-rXX is 7 or 8 and v is 3 or 4.

(Extending FD beam reporting for ranks 5 to 8)
If ranks 5 to 8 are supported in the extension of extension type 2CB, the FD beam reporting for each layer may be extended for ranks 5 to 8. The extension may follow at least one of the following examples.
- Example: for rank 5, i _1,6,5 are reported in addition to the existing report for rank 4.
- Example: For rank 6, i _1,6,5 and i _1,6,6 are reported in addition to the existing report for rank 4.
- Example: For rank 7, i _1,6,5 , i _1,6,6 , and i _1,6,7 are reported in addition to the existing report for rank 4.
- Example: For rank 8, i _1,6,5 , i _1,6,6 , i _1,6,7 , and i _1,6,8 are reported in addition to the existing report for rank 4.

The same FD beam for a particular layer may be supported and reporting of i _1,6,l for a particular layer may not be required. The same FD beam for a particular layer may be applied to any rank. This can reduce the reporting overhead of FD beams. The mapping (relationship) of which layers have the same FD beam may be defined in the specification or may be added and reported by the UE via a new parameter. Having the same FD beam for layers may follow at least one of the following examples:

- Example: If rank is more than 4, FD beams for layers 1, 2, 3, 4 may be reported, and FD beams for layers 5, 6, 7, 8 may not be reported. FD beams for layer i (i>4) may be assumed to be the same as FD beams for layer j (j≦4). For example, FD beams for layer 5 may be the same as FD beams for layer 1, FD beams for layer 6 may be the same as FD beams for layer 2, FD beams for layer 7 may be the same as FD beams for layer 3, and FD beams for layer 8 may be the same as FD beams for layer 4. The mapping between i and j may be defined in the specification or may be additionally reported by the UE via a new parameter. In this case, i _1,6,l may include [i _1,6,1 i _1,6,2 i _1,6,3 i _1,6,4 ].

- Example: If rank is 8, FD beams for layers 5,7 may be reported, and FD beams for layers 6,8 may not be reported. FD beams for layer 6 may be assumed to be the same as FD beams for layer 5. FD beams for layer 8 may be assumed to be the same as FD beams for layer 7. In this case, _i1,6,l may include [ _{i1,6,1 i1,6,2 i1,6,3 i1,6,4 i1,6,5 i1,6,7} ].

The state of reporting FD beams for each layer or omitting reporting FD beams for a specific layer may be defined in the specification (corresponding to UE capabilities) or may be set by the RRC IE.

UE capability may be introduced to support omission of reporting of FD beams for specific layers. UE capability may be introduced to support omission of reporting of FD beams for specific layers.

(Maximum number of NZCs)
For layer l, if the number of FD bases is M _l , then the maximum number of NZCs for layer l may be bounded by K _l =ceil(β×2LM _l ).

A maximum value (limit) of the total number of NZCs for all layers of ranks 5 to 8 of the enhanced CSI-RS may be defined. The maximum value may follow at least one of the following options:

- Option 1: The maximum total number of NZCs is 2K ₀ , the same as the existing maximum total number of NZCs for ranks 2 to 4 (Figure 7A).

- Option 2: The maximum number of NZCs is related/dependent on the rank. For different ranks, the maximum number of NZCs may be different. For example, the maximum may be X*K ₀ , where X may be related/dependent on the rank. This option may be applied for ranks 1 to 4 of the enhanced CSI-RS. In Fig. 7B, the maximum number of NZCs is defined for v=5,6,7,8. In Fig. 7C, the maximum number of NZCs is defined for v=5,6 and for v=7,8. In Fig. 7D, the maximum number of NZCs is defined for v=2, for v=3,4,5,6 and for v=7,8.

The state in which any of the above options apply may be defined in the specification (corresponding to UE capabilities) or may be set by an RRC IE.

UE capability for supporting maximum total number of NZCs for all layers for enhanced CSI-RS may be introduced. UE capability for supporting maximum total number of NZCs for all layers for enhanced CSI-RS may be introduced.

(Method/rules for omitting bitmaps for each layer)
To reduce the reporting overhead of per-layer bitmaps, a method/rule for omission of per-layer bitmaps may be introduced.

A new v-bit indicator i _1,9 may be reported to indicate which layer bitmaps are omitted for rank v. The state of whether bitmap omission is enabled or not may be defined in the specification (corresponding to UE capabilities) or may be configured by an RRC IE. The state may follow at least one of several options:

- Option 1: If all NZCs for layer l are to be not reported, then the bitmap for layer l is omitted (not reported). For example, if the UE determines that all NZCs for a layer have weaker amplitude values (less than a certain value), then the UE may decide not to report that NZC and the bitmap for that layer may not be reported. In this case, there is no reporting of _i1,8,l , _i2,3,l , _i2,4,l , i2,5 _,l for that layer l.

- Option 2: If all NZCs for layer l are to be reported, then the bitmap for layer l is omitted (not reported). For example, if the UE determines that all NZCs for a layer have stronger amplitude values (than a particular value), then the UE may select (report) all NZCs. In this case, there are reports for _i1,8,l , _i2,3,l , i2,4 _,l , and i2,5 _,l for that layer l.

- Option 3: If K ^NZ =2LM ₁ , then no bitmaps for all layers are omitted (not reported). The omission method may be applied for cases where the maximum number of NZCs is defined as X*K ₀ and the rank is less than or equal to X. In this case, the NW can understand that the omission has occurred based on the number of NZCs reported in CSI Part 1. Therefore, reporting of i _1,9 may not be required.

- Option 4: Which bitmap omission rule among options 1 to 3 above applies may be configured by the RRC IE.

- Option 5 (variation): A new 2v bit indicator (2 bits per layer) may be reported to indicate the bitmap omission rule applied by the UE per layer. For example, a value of 00 for the 2v bit indicator may mean no bitmap omission, a value of 01 may mean bitmap omission for option 1 and a value of 10 may mean bitmap omission for option 2.

The state in which any of the above options apply may be defined in the specification (corresponding to UE capabilities) or may be set by an RRC IE.

Such new indicators may be reported in CSI Part 1. These indicators may affect the bit size of CSI Part 2.

UE capabilities for supporting bitmap skipping may be introduced. UE capabilities for supporting new indicators (e.g., v-bit indicator i _1,9 ) to indicate which layer bitmaps are skipped may be introduced. UE capabilities for supporting new indicators (e.g., 2 v-bit indicator i _1,9 ) to indicate the bitmap skipping rule applied per layer may be introduced.

(extension of _i1 , _i2 for ranks 5 to 8)
For ranks 5 to 8, i ₁ , i ₂ may be expanded. The expansion may follow at least one of the following examples.

Example 1: i ₁ , i ₂ for ranks 5 to 8 may be given by:
i ₁ = {
[i _1,1 i _1,2 i _1,5 i _1,6,1 i _1,7,1 i _1,8,1 i _1,6,2 i _1,7,2 i _1,8,2 i _1,6,3 i _1,7,3 i _1,8,3 i _1,6,4 i _1,7,4 i _1,8,4 i _1,6,5 i _1,7,5 i _1,8,5 ] v=5
[i _1,1 i _1,2 i _1,5 i _1,6,1 i _1,7,1 i _1,8,1 i _1,6,2 i _1,7,2 i _1,8,2 i _1,6,3 i _1,7,3 i _1,8,3 i _1,6,4 i _1,7,4 i _1,8,4 i _1,6,5 i _1,7,5 i _1,8,5 i _1,6,6 i _1,7,6 i _1,8,6 ] v=6
[i _1,1 i _1,2 i _1,5 i _1,6,1 i _1,7,1 i _1,8,1 i _1,6,2 i _1,7,2 i _1,8,2 i _1,6,3 i _1,7,3 i _1,8,3 i _1,6,4 i _1,7,4 i _1,8,4 i _1,6,5 i _1,7,5 i _1,8,5 i _1,6,6 i _1,7,6 i _1,8,6 i _1,6,7 i _1,7,7 i _1,8,7 ] v=7
[i _1,1 i _1,2 i _1,5 i _1,6,1 i _1,7,1 i _1,8,1 i _1,6,2 i _1,7,2 i _1,8,2 i _1,6,3 i _1,7,3 i _1,8,3 i _1,6,4 i _1,7,4 i _1,8,4 i _1,6,5 i _1,7,5 i _1,8,5 i _1,6,6 i _1,7,6 i _1,8,6 i _1,6,7 i _1,7,7 i _1,8,7 i _1,6,8 i _1,7,8 i _1,8,8 ] v=8
}
i ₂ = {
_[ i _2,3,1 i _2,4,1 i _2,5,1 i _2,3,2 i _2,4,2 i _2,5,2 i 2,3,3 i _2,4,3 i _2,5,3 i _2,3,4 i _2,4,4 i _2,5,4 i _2,3,5 i _2,4,5 i _2,5,5 ] v=5
[i _2,3,1 i _2,4,1 i _2,5,1 i _2,3,2 i _2,4,2 i _2,5,2 i _2,3,3 i _2,4,3 i _2,5,3 i _2,3,4 i _2,4,4 i _2,5,4 i _2,3,5 i _2,4,5 i _2,5,5 i _2,3,6 i _2,4,6 i _2,5,6 ] v=6
[i _2,3,1 i _2,4,1 i _2,5,1 i _2,3,2 i _2,4,2 i _2,5,2 i _2,3,3 i _2,4,3 i _2,5,3 i _2,3,4 i _2,4,4 i _2,5,4 i _2,3,5 i _2,4,5 i _2,5,5 i _2,3,6 i _2,4,6 i _2,5,6 i _2,3,7 i _2,4,7 i _2,5,7 ] v=7
[i _2,3,1 i _2,4,1 i _2,5,1 i _2,3,2 i _2,4,2 i _2,5,2 i _2,3,3 i _2,4,3 i _2,5,3 i _2,3,4 i _2,4,4 i _2,5,4 i _2,3,5 i _2,4,5 i _2,5,5 i _2,3,6 i _2,4,6 i _2,5,6 i _2,3,7 i _2,4,7 i _2,5,7 i _2,3,8 i _2,4,8 i _2,5,8 ] v=8
}

- Example 2: The above (extension of FD beam reporting for ranks 5 to 8) is applied and i _1,6,l may not be reported. i ₁ for ranks 5 to 8 may be given by:
i ₁ = {
[i _1,1 i _1,2 i _1,5 i _1,6,1 i _1,7,1 i _1,8,1 i _1,6,2 i _1,7,2 i _1,8,2 i 1,6,3 i _1,7,3 i _1,8,3 i _1,6,4 i _1,7,4 i _{1,8,4 i 1,7,5 i 1,8,5} ] v=5
[i _1,1 i _1,2 i _1,5 i _1,6,1 i _1,7,1 i _1,8,1 i _1,6,2 i _1,7,2 i _1,8,2 i _1,6,3 i _1,7,3 i _1,8,3 i _1,6,4 i _1,7,4 i _1,8,4 i _1,7,5 i _1,8,5 i _1,7,6 i _1,8,6 ] v=6
[i _1,1 i _1,2 i _1,5 i _1,6,1 i _1,7,1 i _1,8,1 i _1,6,2 i _1,7,2 i _1,8,2 i _1,6,3 i _1,7,3 i _1,8,3 i _1,6,4 i _1,7,4 i _1,8,4 i _1,7,5 i _1,8,5 i _1,7,6 i _1,8,6 i _1,7,7 i _1,8,7 ] v=7
[i _1,1 i _1,2 i _1,5 i _1,6,1 i _1,7,1 i _1,8,1 i _1,6,2 i _1,7,2 i _1,8,2 i _1,6,3 i _1,7,3 i _1,8,3 i _1,6,4 i _1,7,4 i _1,8,4 i _1,7,5 i _1,8,5 i _1,7,6 i _1,8,6 i _1,7,7 i _1,8,7 i _1,7,8 i _1,8,8 ] v=8
}

Example 3: A new indicator i _1,new may be reported. i ₁ for ranks 1 to 8 may be given by:
i ₁ = {
[i _1,1 i _1,2 i _1,new i _1,5 i _1,6,1 i _1,7,1 i _1,8,1 ] v=1
[i _1,1 i _1,2 i _1,new i _1,5 i _1,6,1 i _1,7,1 i _1,8,1 i _1,6,2 i _1,7,2 i _1,8,2 ] v=2
[i _1,1 i _1,2 i _1,new i _1,5 i _1,6,1 i _1,7,1 i _1,8,1 i _1,6,2 i 1,7,2 i _1,8,2 i _{1,6,3 i 1,7,3 i 1,8,3} ] v=3
[i _1,1 i _1,2 i _1,new i _1,5 i _1,6,1 i _1,7,1 i _1,8,1 i _1,6,2 i _1,7,2 i 1,8,2 i _1,6,3 i _1,7,3 i _{1,8,3 i 1,6,4} i _1,7,4 i _1,8,4 ] v=4
[i _1,1 i _1,2 i _1,new i _1,5 i _1,6,1 i _1,7,1 i _1,8,1 i _1,6,2 i _1,7,2 i _1,8,2 i _1,6,3 i _1,7,3 i _1,8,3 i _1,6,4 i _1,7,4 i _1,8,4 i _1,6,5 i _1,7,5 i _1,8,5 ] v=5
[i _1,1 i _1,2 i _1,new i _1,5 i _1,6,1 i _1,7,1 i _1,8,1 i _1,6,2 i _1,7,2 i _1,8,2 i _1,6,3 i _1,7,3 i _1,8,3 i _1,6,4 i _1,7,4 i _1,8,4 i _1,6,5 i _1,7,5 i _1,8,5 i _1,6,6 i _1,7,6 i _1,8,6 ] v=6
[i _1,1 i _1,2 i _1,new i _1,5 i _1,6,1 i _1,7,1 i _1,8,1 i _1,6,2 i _1,7,2 i _1,8,2 i _1,6,3 i _1,7,3 i _1,8,3 i _1,6,4 i _1,7,4 i _1,8,4 i _1,6,5 i _1,7,5 i _1,8,5 i _1,6,6 i _1,7,6 i _1,8,6 i _1,6,7 i _1,7,7 i _1,8,7 ] v=7
[i _1,1 i _1,2 i _1,new i _1,5 i _1,6,1 i _1,7,1 i _1,8,1 i _1,6,2 i _1,7,2 i _1,8,2 i _1,6,3 i _1,7,3 i _1,8,3 i _1,6,4 i _1,7,4 i _1,8,4 i _1,6,5 i _1,7,5 i _1,8,5 i _1,6,6 i _1,7,6 i _1,8,6 i _1,6,7 i _1,7,7 i _1,8,7 i _1,6,8 i _1,7,8 i _1,8,8 ] v=8
}

Example 4: A new indicator i _1,9 may be reported. i ₁ for ranks 1 to 8 may be given by:
i ₁ = {
[i _1,1 i _1,2 i _1,5 i _1,9 i _1,6,1 i _1,7,1 i _1,8,1 ] v=1
[i _1,1 i _1,2 i _1,5 i _1,9 i _1,6,1 i _1,7,1 i _1,8,1 i _1,6,2 i _1,7,2 i _1,8,2 ] v=2
[i _1,1 i _1,2 i _1,5 i _1,9 i _1,6,1 i _1,7,1 i _1,8,1 i 1,6,2 i _1,7,2 i _1,8,2 i _{1,6,3 i 1,7,3 i 1,8,3} ] v=3
[i _1,1 i _1,2 i _1,5 i _1,9 i _1,6,1 i 1,7,1 i _1,8,1 i _1,6,2 i _1,7,2 i _1,8,2 i _1,6,3 i _1,7,3 i _{1,8,3 i 1,6,4} i _1,7,4 i _1,8,4 ] v=4
[i _1,1 i _1,2 i _1,5 i _1,9 i _1,6,1 i _1,7,1 i _1,8,1 i _1,6,2 i _1,7,2 i 1,8,2 i _1,6,3 i _1,7,3 i _1,8,3 i _1,6,4 i _1,7,4 i _1,8,4 i _{1,6,5 i 1,7,5} i _1,8,5 ] v=5
[i _1,1 i _1,2 i _1,5 i _1,9 i _1,6,1 i _1,7,1 i _1,8,1 i _1,6,2 i _1,7,2 i 1,8,2 i _1,6,3 i _1,7,3 i _1,8,3 i _1,6,4 i _1,7,4 i _1,8,4 i _{1,6,5 i 1,7,5} i _1,8,5 i _1,6,6 i _1,7,6 i _1,8,6 ] v=6
[i _1,1 i _1,2 i _1,5 i _1,9 i _1,6,1 i _1,7,1 i _1,8,1 i _1,6,2 i _1,7,2 i 1,8,2 i _1,6,3 i _1,7,3 i _1,8,3 i _1,6,4 i _1,7,4 i _1,8,4 i _{1,6,5 i 1,7,5} i _1,8,5 i _1,6,6 i _1,7,6 i _1,8,6 i _1,6,7 i _1,7,7 i _1,8,7 ] v=7
[i _1,1 i _1,2 i _1,5 i _1,9 i _1,6,1 i _1,7,1 i _1,8,1 i _1,6,2 i _1,7,2 i 1,8,2 i _1,6,3 i _1,7,3 i _1,8,3 i _1,6,4 i _1,7,4 i _1,8,4 i _{1,6,5 i 1,7,5} i _1,8,5 i _1,6,6 i _1,7,6 i _1,8,6 i _1,6,7 i _1,7,7 i _1,8,7 i _1,6,8 i _1,7,8 i _1,8,8 ] v=8
}

(analysis)
As described above, for example, in AI/ML-based CSI feedback, CSI compression is performed. In the CSI compression and feedback, it is preferable that the UE reports high-precision CSI (ground-truth CSI) to the NW for at least one of data collection and performance monitoring on the NW side. In order to report the ground-truth CSI, it is possible to apply high-precision CSI feedback (e.g., CSI with enhanced type 2 or enhanced type 2 port selection codebook applied).

In AI/ML-based CSI feedback, a layer-common model is being considered to support multi-layer CSI reports, such as 8-layer CSI reports. The layer-common model is a model that supports multiple numbers of layers, meaning that a common model can be used for both 2-layer and 8-layer cases. In addition, data collection of extended type-II ground truth CSI is being considered for model training.

However, the method for reporting high-precision CSI when CSI compression is performed is not clear. For example, it is not clear how to determine parameters for an extended Type 2 codebook for ranks or layers greater than 4. If the method for determining these parameters is not made clear, there is a risk that high-precision CSI used for comparison with compressed CSI cannot be properly transmitted, and proper CSI feedback using AI cannot be achieved.

The inventors therefore came up with the idea of a terminal that can provide appropriate CSI feedback.

(Various changes in interpretation, etc.)
Hereinafter, embodiments according to the present disclosure will be described in detail with reference to the drawings. Wireless communication methods according to the embodiments may be applied independently or in combination.

In this disclosure, "A/B" and "at least one of A and B" may be interpreted as interchangeable. Also, in this disclosure, "A/B/C" may mean "at least one of A, B, and C."

In this disclosure, terms such as notify, activate, deactivate, indicate, select, configure, update, and determine may be read as interchangeable terms. In this disclosure, terms such as support, control, capable of control, operate, and capable of operating may be read as interchangeable terms.

In this disclosure, Radio Resource Control (RRC), RRC parameters, RRC messages, higher layer parameters, fields, information elements (IEs), settings, etc. may be interchangeable. In this disclosure, Medium Access Control (MAC Control Element (CE)), update commands, activation/deactivation commands, etc. may be interchangeable.

In the present disclosure, the higher layer signaling may be, for example, any one of Radio Resource Control (RRC) signaling, Medium Access Control (MAC) signaling, broadcast information, other messages (e.g., messages from the core network such as positioning protocols (e.g., NR Positioning Protocol A (NRPPa)/LTE Positioning Protocol (LPP)) messages), or a combination of these.

In the present disclosure, the MAC signaling may use, for example, a MAC Control Element (MAC CE), a MAC Protocol Data Unit (PDU), etc. The broadcast information may be, for example, a Master Information Block (MIB), a System Information Block (SIB), Remaining Minimum System Information (RMSI), Other System Information (OSI), etc.

In the present disclosure, the physical layer signaling may be, for example, Downlink Control Information (DCI), Uplink Control Information (UCI), etc.

In the present disclosure, the autoencoder, encoder, decoder, etc. may be interpreted as at least one of a model, an ML model, a neural network model, an AI model, an AI algorithm, etc. Furthermore, the autoencoder may be interpreted as any autoencoder, such as a stacked autoencoder or a convolutional autoencoder. The encoder/decoder of the present disclosure may employ models such as Residual Network (ResNet), DenseNet, and RefineNet.

Furthermore, in this disclosure, the terms encoder, encoding, encoding, modification/change/control by an encoder, etc. may be read as interchangeable terms. Further, in this disclosure, the terms decoder, decoding, decoding, modification/change/control by a decoder, etc. may be read as interchangeable terms.

In the present disclosure, UCI, CSI report, CSI feedback, feedback information, feedback bit, etc. may be interchangeable. Also, in the present disclosure, bit, bit string, bit sequence, sequence, value, information, value obtained from a bit, information obtained from a bit, etc. may be interchangeable.

In the following embodiments, to explain an AI model for UE-BS communication, the relevant entities are UE and BS, but the application of each embodiment of the present disclosure is not limited to this. For example, for communication between different entities (e.g., UE-UE communication), the UE and BS in the following embodiments may be read as a first UE and a second UE. In other words, the UE, BS, etc. in the present disclosure may be read as any UE/BS. The network (NW), base station (BS), and gNB may be read as each other.

In this disclosure, the terms model and AI/ML model may be interchangeable. Compression, encoding, and application of the AI/ML model may be interchangeable.

In the present disclosure, CSI, target CSI, CSI calculated based on UE measurements, ideal CSI (simulated CSI, fixed value), actual CSI, ground truth CSI, and uncompressed CSI may be interchangeable. Type 2 and Type II may be interchangeable. Extended Type 2 and eTypeII may be interchangeable. CSI, AI/ML-based CSI, compressed CSI, and predicted CSI may be interchangeable.

In the present disclosure, beam, SD beam, spatial domain index, ( _i1,1 , _i1,2 ), (l,m), precoding, precoder, quasi co-location (QCL) assumption, QCL relationship, transmission configuration indicator (TCI) state, spatial domain filter, spatial domain receive filter, spatial domain transmit filter, reference signal (RS), and spatial receive parameters may be interpreted as interchangeable.

In this disclosure, the terms codebook, codebook structure, codebook design, precoding matrix, relationship between precoding matrix and codebook index, CSI report, and PMI may be interchangeable.

Rank, RI, layer, and v may be interchangeable. Vector and SD vector may be interchangeable.

(Wireless communication method)
First Embodiment
In the first embodiment, the UE may apply the updated codebook parameter configuration. The UE may receive a configuration/instruction (e.g., parameter “paramCombination-rXX”) regarding a codebook for CSI reporting, and may determine the values of parameters L, P _v , β for an extended type-II (type-2) codebook corresponding to rank/layers greater than 4 for CSI reporting based on the configuration/instruction and the configuration table, and control the transmission of the CSI report.

FIG. 8 is a diagram showing a codebook parameter setting table in the first embodiment. The table in FIG. 8 is an example in which the example of the table in FIG. 6 is further extended. As shown in FIG. 8, L, P _v , β corresponding to some indexes (e.g., paramCombination-rXX=1, ..., 8) of the parameter setting table may be the same as the value corresponding to paramCombination-r16 in FIG. 6 (excluding the definition of P _v for v=5, ..., 8). In addition, for additional indexes (e.g., paramCombination-rXX greater than 8) of the parameter setting table, P _v for v=5, ..., 8 is set. When a parameter configuration index (e.g., paramCombination-rXX) greater than 8 is set, the UE may transmit a CSI report corresponding to RI>4 (i.e., v>4).

According to the first embodiment, it is possible to appropriately set a codebook for CSI reporting that corresponds to ranks/layers greater than 4.

Second Embodiment
In the second embodiment, the codebook parameter configuration table may be extended based on the rule. When the UE receives a configuration related to a codebook for CSI reporting (e.g., paramCombination-rXX, paramCombination-r16) and further receives a configuration allowing reporting of a large rank/layer (e.g., rank or layer greater than 4) or a configuration for enabling an extension of the parameter configuration table (e.g., typeII-RI-Restriction-rXX), the UE may determine values of parameters L, P _v , β for an extended type-II codebook for ranks or layers greater than 4.

The UE may perform the following actions if the configured maximum allowed RI(v) is greater than a threshold (e.g., 4). The threshold may be another constant or a number based on L (e.g., 2L).

The UE may determine the value of L based on the maximum acceptable RI (max RI) (e.g., L=(max RI)/2, L=(max RI)/2+1, or L=(max RI)/2+1), where L=(max RI)/2 provides the minimum degree of freedom (DoF) required to report non-singular CSI.

Based on at least one P _v of v ∈ {1,2}, v ∈ {3,4}, P _v when v ∈ {5,6,...,8} may be determined/used. For example, P _v of v ∈ {1,2}, v ∈ {3,4}, or a number obtained by dividing that P _v by 2 or 4 may be determined/used as P _v when v ∈ {5,6,...,8}. The UE may use a number obtained by adding a specific value (e.g., 2) to the L value for a specified part or all of the entries of the codebook parameter setting table. For example, the UE may use L = 4 when the table indicates L = 2, or use L = 6 when the table indicates L = 4. Note that when L = 4, sufficient DoF can be provided up to RI = 8, but a higher L may be required when accuracy is taken into consideration.

Fig. 9A is a diagram showing a first example of codebook parameters of the second embodiment. Fig. 9A shows an example in which the UE determines/uses P _v when L and v ∈ {5, 6, ..., 8} based on one parameter (paramCombination-rXX = 1) in the codebook parameter setting table of Fig. 6. Here, it is assumed that typeII-RI-Restriction-rXX allows RI = 8. The UE uses a number obtained by adding 2 to the L value in the codebook parameter setting table as the L value. In addition, the UE determines/uses the same value as P _v for v ∈ {3, 4} as P _v for v ∈ {5, 6}, and determines/uses a value obtained by dividing P _v for v ∈ {3, 4} by 2 as P _v for v ∈ {7, 8}.

Fig. 9B is a diagram showing a second example of codebook parameters of the second embodiment. Fig. 9B shows an example in which the UE determines/uses P _v when L and v ∈ {5, 6, ..., 8} based on two parameters (paramCombination-rXX = 1 or 3) in the codebook parameter setting table of Fig. 6. The method of determining L and P _v is the same as the example of Fig. 9A.

In the above example, a method has been described in which the UE determines _Pv corresponding to v greater than 4 based on a table in which v greater than 4 is not set (e.g., FIG. 4 or FIG. 6). However, if a table corresponding to v greater than 4 (e.g., FIG. 9A and FIG. 9B) is pre-configured and the UE receives a configuration allowing reporting of ranks/layers greater than 4 or a configuration for enabling an extension of the parameter configuration table, the UE may use the table corresponding to v greater than 4.

According to the second embodiment, a codebook for CSI reporting that corresponds to a rank/layer greater than 4 can be appropriately set. Furthermore, ranks/layers greater than 4 can be applied without updating existing tables (tables in which v greater than 4 is not set). The number of spatial vectors (L) is also expanded, which can avoid singularities in the reported CSI and improve accuracy.

Third Embodiment
In the third embodiment, multiple SD vector groups for an extended type-II codebook are described. If the maximum allowed RI(v) is greater than a certain value (e.g., 4), the UE may take the following actions. Note that in the following description, the SD vector may be simply referred to as a vector.

The UE may select/use different vectors for different layers. For example, the UE may select multiple groups per layer for CSI reporting, with L vectors per group. The UE may receive a configuration/indication/specification of the number of groups of vectors and the mapping between layer index and group index.

For example, the UE may receive a configuration/instruction/designation via higher layer signaling/physical layer signaling indicating that it will use group #0 containing L vectors for layers #0 to #N1, and group #1 containing another L vectors for layers #N1+1 to #N2.

For example, the UE may select L vectors for CSI of layers #0 to #3 and another L vectors for CSI of layers #4 and above. The CSI is determined by L+L vectors.

At least one vector may overlap between the groups, i.e., different groups may have at least one same vector, or the vectors included in the two groups may be identical. This embodiment may be performed in combination with the second embodiment, i.e., the UE may apply the operation of the second embodiment to determine the value of P _v ,β.

If v is 4 or less, an existing codebook (e.g., the above-mentioned Rel. 16) is used. In this case, _q1 , _q2 , _n1 , and _n2 in FIG. 5 indicate the first group corresponding to the selected L vectors. If v is 5 or more, a second _{group of vectors is used by replacing n1, n2} ^{with n1H} _, ^n2H _{, where n1H} , _n2H indicate the second group of the selected L vectors. For example, the codebook for v= ⁵ is expressed as follows. Note that the same parts as in the case of v=4 are omitted in the following equation (see the equation for v=4 in FIG. 5).

According to this embodiment, the UE can use an appropriate SD vector depending on the layer.

Fourth Embodiment
Under the conditions defined in the second/third embodiment, the UE may perform the following additional operations: The UE may determine the value of the parameter for the extended type-II codebook using different tables/methods depending on the number of ranks/layers for the CSI report to be reported. Note that reporting a specific RI(v) (e.g., RI(v)≦4) and setting a specific RI(v) may be interpreted as interchangeable.

If the UE reports RI(v)≦4, the UE may use L, P _v , β based on the tables in Figure 4 or Figure 6. That is, the UE may fall back on the codebook parameter setting table when RI(v) is below a certain value.

The UE may apply the second/third embodiment when reporting a CSI report corresponding to RI(v) larger than a certain value (e.g., 4) or larger than the value that can be supported in the paramCombination-r16 table. In this case, the UE may determine/use L, P _v , β based on, for example, the relationship in Figure 9A or Figure 9B.

For example, if paramCombination-rXX=1 to 8 is set, the maximum RI is set to 8 by typeII-RI-Restriction-rXX, and the UE reports RI(v) as 1 to 4, the UE may use L, P _v , β based on the table in Figure 4 or 6. If paramCombination-rXX=1 to 8 is set, the maximum RI is allowed to be 8 by typeII-RI-Restriction-rXX, and the UE reports RI(v) as 4 to 8, the UE may use L, P _v , β based on the table in Figure 9A or 9B.

According to this embodiment, the parameter values for the extended type II codebook can be appropriately determined depending on the number of ranks/layers.

Fifth embodiment
When the UE applies at least one of the first to fourth embodiments to transmit a CSI report for a rank or layer greater than four, at least one of the following operations may be performed.

The UE may report CSI content i _1,6,l for l=5,6,7,8 by applying the above (extension of FD beam reporting for ranks 5 to 8).

The UE may determine the maximum number of non-zero coefficients to report by applying the above (maximum number of NZC).

The UE may report bitmaps indicating the reported coefficients in i _1,7,l for l=5,6,7,8 or may apply the above (method/rule for bitmap omission per layer).

The UE may report CSI content as in the example shown above (extension of i1, i2 for ranks 5 to 8), such as reporting _i1,8,l , _i2,3,l , _i2,4,l , _i2,5,l for l=5,6,7,8.

In addition to _i1,2 , if multiple vector groups are selected to determine CSI applying the above (extension of FD beam reporting for ranks 5 to 8), the UE may report i1,2 _{,H or i1,2 ,g} (g=2,3...), where _i1,2 , i1,2, _{H and i1,2,g} are defined as follows:
i _1,2 indicates the selected vector of the layer with the lower index (eg, layers #0 to #3) or the selected vector of the first group.
i _1,2,H indicates the selected vector of the layer with the higher index (e.g., layers #4-#7) or the selected vector of the second group (if the number of groups is 2).
i _1,2,g (g=2,3...N) indicates the selected vectors in the 2nd, 3rd, ..., Nth group (N may be the maximum number of groups or any other value).

Sixth Embodiment
The UE may apply the operations of the first to fifth embodiments to the extended type II (extended type 2) port selection codebook. That is, the extended type II codebook of the first to fifth embodiments may be replaced with the extended type II port selection codebook. For example, the codebook parameter setting table may be extended as shown in the second/third embodiments based on FIG. 4 or FIG. 6. For example, when applying the third embodiment, the UE may select multiple port groups for each layer, including a specific number (L) of ports per group. That is, the vector (SD vector) of the third embodiment may be replaced with a port.

The UE may report CSI content i _1,6,l for l=5,6,7,8 by applying the above (extension of FD beam reporting for ranks 5 to 8).

The UE may determine the maximum number of non-zero coefficients to report by applying the above (maximum number of NZC).

The UE may report bitmaps indicating the reported coefficients in i _1,7,l for l=5,6,7,8 or may apply the above (method/rule for bitmap omission per layer).

The UE can report CSI content as in the example shown above (extension of i1, i2 for ranks 5 to 8), such as reporting _i1,8,l , _i2,3,l , _i2,4,l , _i2,5,l for l=5,6,7,8.

If multiple vector groups are selected to determine CSI by applying the above (extension of FD beam reporting for ranks 5 to 8), the UE may report _i1,1,H or _i1,1,g (g=2,3...) in addition to _i1,1 , where _i1,1,H and i1,1 _,g are defined as follows:
i _1,2 indicates the selected vector of the layer with the lower index (eg, layers #0 to #3) or the selected vector of the first group.
i _1,1,H indicates the selected vector of the layer with the higher index (e.g., layers #4-#7) or the selected vector of the second group (if the number of groups is 2).
i _1,1,g (g=2,3...N) indicates the selection vectors of the 2nd, 3rd, ..., Nth group (N may be the maximum number of groups or any other value).

FIG. 10 illustrates a codebook for 1-layer, 2-layer, 3-layer, and 4-layer CSI reporting using antenna ports 3000 to 2999+P _CSI-RS in an extended Type II port selection codebook.

If v is greater than 4, the second group of coefficients/ports is used by replacing _i1,1 with _i1,1,H , where _i1,1,H denotes the second group containing the selected L ports. For example, the codebook for v=5 is shown in the following equation. Note that the same parts as in the case of v=4 are omitted in the following equation (see the equation for v=4 in FIG. 10).

According to the sixth embodiment, even when an extended type II port selection codebook is applied, the codebook for CSI reporting can be appropriately set.

<Additional Information>
[Notification of information to UE]
In the above-described embodiment, any information may be notified to the UE (from a network (NW) (e.g., a base station (BS))) (in other words, any information is received from the BS by the UE) using physical layer signaling (e.g., DCI), higher layer signaling (e.g., RRC signaling, MAC CE), a specific signal/channel (e.g., PDCCH, PDSCH, reference signal), or a combination thereof.

When the above notification is performed by a MAC CE, the MAC CE may be identified by including in the MAC subheader a new Logical Channel ID (LCID) that is not specified in existing standards.

When the notification is made by a DCI, the notification may be made by a specific field of the DCI, a Radio Network Temporary Identifier (RNTI) used to scramble Cyclic Redundancy Check (CRC) bits assigned to the DCI, the format of the DCI, etc.

Furthermore, notification of any information to the UE in the above-mentioned embodiments may be performed periodically, semi-persistently, or aperiodically.

[Information notification from UE]
In the above-described embodiments, notification of any information from the UE (to the NW) (in other words, transmission/report of any information from the UE to the BS) may be performed using physical layer signaling (e.g., UCI), higher layer signaling (e.g., RRC signaling, MAC CE), a specific signal/channel (e.g., PUCCH, PUSCH, PRACH, reference signal), or a combination thereof.

If the notification is made by a MAC CE, the MAC CE may be identified by including a new LCID in the MAC subheader that is not specified in existing standards.

If the notification is made by UCI, the notification may be transmitted using PUCCH or PUSCH.

Furthermore, in the above-mentioned embodiments, notification of any information from the UE may be performed periodically, semi-persistently, or aperiodically.

[Application of each embodiment]
At least one of the above-mentioned embodiments may be applied when a specific condition is met, which may be specified in a standard or may be notified to a UE/BS using higher layer signaling/physical layer signaling.

At least one of the above-described embodiments may be applied only to UEs that have reported a particular UE capability or that support the particular UE capability. Note that "supporting" and "whether or not to support" may be interpreted as interchangeable.

The specific UE capabilities may indicate at least one of the following:
Supporting specific processing/operations/control/information for at least one of the above embodiments;
Supporting specific features/models of AI/ML;
Support codebook restriction (e.g., Type I/Type II/Extended Type II codebook restriction) for CSI with AI/ML;
Number of beam groups for codebook restriction Number of SD vectors or number of groups containing SD vectors.

Furthermore, the above-mentioned specific UE capabilities may be capabilities that are applied across all frequencies (commonly regardless of frequency), capabilities per frequency (e.g., one or a combination of a cell, band, band combination, BWP, component carrier, etc.), capabilities per frequency range (e.g., Frequency Range 1 (FR1), FR2, FR3, FR4, FR5, FR2-1, FR2-2), capabilities per subcarrier spacing (SubCarrier Spacing (SCS)), or capabilities per Feature Set (FS) or Feature Set Per Component-carrier (FSPC).

The above-mentioned specific UE capabilities may be capabilities that are applied across all duplexing methods (commonly regardless of the duplexing method), or may be capabilities for each duplexing method (e.g., Time Division Duplex (TDD) and Frequency Division Duplex (FDD)).

Furthermore, at least one of the above-mentioned embodiments may be applied when the UE configures/activates/triggers specific information related to the above-mentioned embodiments (or performs the operations of the above-mentioned embodiments) by higher layer signaling/physical layer signaling. For example, the specific information may be any RRC parameters for a specific release (e.g., Rel. 18/19), etc.

If the UE does not support at least one of the above specific UE capabilities or the above specific information is not configured, the UE may apply, for example, the behavior of Rel. 15/16/17.

[others]
In this disclosure, functionality may mean a set of parameters (e.g., a set of parameters for CSI prediction/beam prediction/CSI compression) that may be supported based on conditions dictated by the UE capabilities.

The UE may report parameter values related to the functionality/model as conditions to the NW via higher layer signaling (e.g., RRC, MAC CE)/physical layer signaling (e.g., DCI). For example, the UE may report conditions using UE capability/feature/feature group reporting.

The UE may report or instruct the NW on parameter values related to the functionality/model as additional conditions using higher layer signaling/physical layer signaling or methods other than signaling over the air interface of the NW (e.g. operator's configurations, pre-configured messages, etc.).

The UE may report or be instructed on information/instructions on the parameters corresponding to these additional conditions (e.g., parameter names) as information/instructions on the additional conditions using higher layer signaling/physical layer signaling or methods other than signaling over the air interface of the network (e.g., operator's configurations, preconfigured messages, etc.).

For example, the UE may report a device ID, a vendor ID, etc. as additional information. The UE may also be notified of a cell ID as an additional condition. The UE may also report or be instructed to report information such as a cell ID/UE ID instead of a parameter name.

Methods other than signaling via the air interface of the network may be pre-configuration of the UE (e.g., configuration by the UE vendor) or methods related to operator configuration provided by the network operator.

The AI/ML-based CSI report may be a CSI report associated with a model ID or a specific feature (e.g., predicted CSI, compressed CSI, advanced CSI, a specific type of CSI, etc.). The AI/ML feature, or the AI/ML feature for CSI, or the feature for CSI may be based on a feature indicated by the NW or a feature reported by the UE (capability information), e.g., predicted CSI, compressed CSI, advanced CSI, a feature for a specific type of CSI. The AI/ML model, or the AI/ML model for CSI, or the model for CSI may be a model/entity identified by a model ID or its feature and performing the specific feature mentioned above.

(Additional Note)
With respect to one embodiment of the present disclosure, the following invention is noted.
[Appendix 1]
a receiver for receiving a configuration regarding a codebook for channel state information (CSI) reporting;
a control unit that determines, based on the configuration, values of parameters for an extended type-2 codebook for ranks or layers greater than 4 for CSI reporting;
A terminal having the above configuration.
[Appendix 2]
The receiver receives a second setting for enabling an extension of a first setting or a parameter setting table to allow reporting of ranks or layers greater than four;
The terminal according to claim 1, wherein the control unit determines, when receiving the first setting or the second setting, values of parameters for an extended type-2 codebook for a rank or layer greater than 4.
[Appendix 3]
3. The terminal of claim 1, wherein the controller selects different spatial domain (SD) vectors for different layers.
[Appendix 4]
The terminal according to any one of Supplementary Note 1 to Supplementary Note 3, wherein the controller determines values of parameters for the extended type-2 codebook using different tables depending on the number of ranks or layers for the CSI report.

(Additional Note)
With respect to one embodiment of the present disclosure, the following invention is noted.
[Appendix 1]
a receiver for receiving a configuration regarding a codebook for channel state information (CSI) reporting;
a control unit that determines, based on the configuration, values of parameters for an extended type 2-port selection codebook for ranks or layers greater than 4 for CSI reporting;
A terminal having the above configuration.
[Appendix 2]
The receiver receives a second setting for enabling an extension of a first setting or a parameter setting table to allow reporting of ranks or layers greater than four;
The terminal of claim 1, wherein the control unit determines, when receiving the first setting or the second setting, a value of a parameter for an extended type 2 port selection codebook for a rank or layer greater than 4.
[Appendix 3]
3. The terminal according to claim 1 or 2, wherein the control unit selects different ports for different layers.
[Appendix 4]
The terminal according to any one of Supplementary Note 1 to Supplementary Note 3, wherein the controller determines values of parameters for the extended type 2 port selection codebook using different tables depending on the number of ranks or layers for the CSI report.

(Wireless communication system)
A configuration of a wireless communication system according to an embodiment of the present disclosure will be described below. In this wireless communication system, communication is performed using any one of the wireless communication methods according to the above embodiments of the present disclosure or a combination of these methods.

FIG. 11 is a diagram showing an example of a schematic configuration of a wireless communication system according to an embodiment. The wireless communication system 1 (which may simply be referred to as system 1) may be a system that realizes communication using Long Term Evolution (LTE) specified by the Third Generation Partnership Project (3GPP), 5th generation mobile communication system New Radio (5G NR), or the like.

The wireless communication system 1 may also support dual connectivity between multiple Radio Access Technologies (RATs) (Multi-RAT Dual Connectivity (MR-DC)). MR-DC may include dual connectivity between LTE (Evolved Universal Terrestrial Radio Access (E-UTRA)) and NR (E-UTRA-NR Dual Connectivity (EN-DC)), dual connectivity between NR and LTE (NR-E-UTRA Dual Connectivity (NE-DC)), etc.

In EN-DC, the LTE (E-UTRA) base station (eNB) is the master node (MN), and the NR base station (gNB) is the secondary node (SN). In NE-DC, the NR base station (gNB) is the MN, and the LTE (E-UTRA) base station (eNB) is the SN.

The wireless communication system 1 may support dual connectivity between multiple base stations within the same RAT (e.g., dual connectivity in which both the MN and SN are NR base stations (gNBs) (NR-NR Dual Connectivity (NN-DC))).

The wireless communication system 1 may include a base station 11 that forms a macrocell C1 with a relatively wide coverage, and base stations 12 (12a-12c) that are arranged within the macrocell C1 and form a small cell C2 that is narrower than the macrocell C1. A user terminal 20 may be located within at least one of the cells. The arrangement and number of each cell and user terminal 20 are not limited to the embodiment shown in the figure. Hereinafter, when there is no need to distinguish between the base stations 11 and 12, they will be collectively referred to as base station 10.

The user terminal 20 may be connected to at least one of the multiple base stations 10. The user terminal 20 may utilize at least one of carrier aggregation (CA) using multiple component carriers (CC) and dual connectivity (DC).

Each CC may be included in at least one of a first frequency band (Frequency Range 1 (FR1)) and a second frequency band (Frequency Range 2 (FR2)). Macro cell C1 may be included in FR1, and small cell C2 may be included in FR2. For example, FR1 may be a frequency band below 6 GHz (sub-6 GHz), and FR2 may be a frequency band above 24 GHz (above-24 GHz). Note that the frequency bands and definitions of FR1 and FR2 are not limited to these, and for example, FR1 may correspond to a higher frequency band than FR2.

In addition, the user terminal 20 may communicate using at least one of Time Division Duplex (TDD) and Frequency Division Duplex (FDD) in each CC.

The multiple base stations 10 may be connected by wire (e.g., optical fiber conforming to the Common Public Radio Interface (CPRI), X2 interface, etc.) or wirelessly (e.g., NR communication). For example, when NR communication is used as a backhaul between base stations 11 and 12, base station 11, which corresponds to the upper station, may be called an Integrated Access Backhaul (IAB) donor, and base station 12, which corresponds to a relay station, may be called an IAB node.

The base station 10 may be connected to the core network 30 via another base station 10 or directly. The core network 30 may include, for example, at least one of an Evolved Packet Core (EPC), a 5G Core Network (5GCN), a Next Generation Core (NGC), etc.

The core network 30 may include network functions (Network Functions (NF)) such as, for example, a User Plane Function (UPF), an Access and Mobility management Function (AMF), a Session Management Function (SMF), a Unified Data Management (UDM), an Application Function (AF), a Data Network (DN), a Location Management Function (LMF), and Operation, Administration and Maintenance (Management) (OAM). Note that multiple functions may be provided by one network node. In addition, communication with an external network (e.g., the Internet) may be performed via the DN.

The user terminal 20 may be a terminal that supports at least one of the communication methods such as LTE, LTE-A, and 5G.

In the wireless communication system 1, a wireless access method based on Orthogonal Frequency Division Multiplexing (OFDM) may be used. For example, in at least one of the downlink (DL) and uplink (UL), Cyclic Prefix OFDM (CP-OFDM), Discrete Fourier Transform Spread OFDM (DFT-s-OFDM), Orthogonal Frequency Division Multiple Access (OFDMA), Single Carrier Frequency Division Multiple Access (SC-FDMA), etc. may be used.

The radio access method may also be called a waveform. Note that in the wireless communication system 1, other radio access methods (e.g., other single-carrier transmission methods, other multi-carrier transmission methods) may be used for the UL and DL radio access methods.

In the wireless communication system 1, a downlink shared channel (Physical Downlink Shared Channel (PDSCH)) shared by each user terminal 20, a broadcast channel (Physical Broadcast Channel (PBCH)), a downlink control channel (Physical Downlink Control Channel (PDCCH)), etc. may be used as the downlink channel.

In addition, in the wireless communication system 1, an uplink shared channel (Physical Uplink Shared Channel (PUSCH)) shared by each user terminal 20, an uplink control channel (Physical Uplink Control Channel (PUCCH)), a random access channel (Physical Random Access Channel (PRACH)), etc. may be used as an uplink channel.

User data, upper layer control information, System Information Block (SIB), etc. are transmitted via PDSCH. User data, upper layer control information, etc. may also be transmitted via PUSCH. Furthermore, Master Information Block (MIB) may also be transmitted via PBCH.

Lower layer control information may be transmitted by the PDCCH. The lower layer control information may include, for example, downlink control information (Downlink Control Information (DCI)) including scheduling information for at least one of the PDSCH and the PUSCH.

Note that the DCI for scheduling the PDSCH may be called a DL assignment or DL DCI, and the DCI for scheduling the PUSCH may be called a UL grant or UL DCI. Note that the PDSCH may be interpreted as DL data, and the PUSCH may be interpreted as UL data.

A control resource set (COntrol REsource SET (CORESET)) and a search space may be used to detect the PDCCH. The CORESET corresponds to the resources to search for DCI. The search space corresponds to the search region and search method of PDCCH candidates. One CORESET may be associated with one or multiple search spaces. The UE may monitor the CORESET associated with a search space based on the search space configuration.

A search space may correspond to PDCCH candidates corresponding to one or more aggregation levels. One or more search spaces may be referred to as a search space set. Note that the terms "search space," "search space set," "search space setting," "search space set setting," "CORESET," "CORESET setting," etc. in this disclosure may be read as interchangeable.

The PUCCH may transmit uplink control information (UCI) including at least one of channel state information (CSI), delivery confirmation information (which may be called, for example, Hybrid Automatic Repeat reQuest ACKnowledgement (HARQ-ACK), ACK/NACK, etc.), and a scheduling request (SR). The PRACH may transmit a random access preamble for establishing a connection with a cell.

Note that in this disclosure, downlink, uplink, etc. may be expressed without adding "link." Also, various channels may be expressed without adding "Physical" to the beginning.

In the wireless communication system 1, a synchronization signal (SS), a downlink reference signal (DL-RS), etc. may be transmitted. In the wireless communication system 1, as the DL-RS, a cell-specific reference signal (CRS), a channel state information reference signal (CSI-RS), a demodulation reference signal (DMRS), a positioning reference signal (PRS), a phase tracking reference signal (PTRS), etc. may be transmitted.

The synchronization signal may be, for example, at least one of a Primary Synchronization Signal (PSS) and a Secondary Synchronization Signal (SSS). A signal block including an SS (PSS, SSS) and a PBCH (and a DMRS for PBCH) may be called an SS/PBCH block, an SS Block (SSB), etc. In addition, the SS, SSB, etc. may also be called a reference signal.

In addition, in the wireless communication system 1, a measurement reference signal (Sounding Reference Signal (SRS)), a demodulation reference signal (DMRS), etc. may be transmitted as an uplink reference signal (UL-RS). Note that the DMRS may also be called a user equipment-specific reference signal (UE-specific Reference Signal).

(base station)
12 is a diagram showing an example of a configuration of a base station according to an embodiment. The base station 10 includes a control unit 110, a transceiver unit 120, a transceiver antenna 130, and a transmission line interface 140. Note that one or more of each of the control unit 110, the transceiver unit 120, the transceiver antenna 130, and the transmission line interface 140 may be provided.

Note that this example mainly shows the functional blocks of the characteristic parts of this embodiment, and the base station 10 may also be assumed to have other functional blocks necessary for wireless communication. Some of the processing of each part described below may be omitted.

The control unit 110 controls the entire base station 10. The control unit 110 can be configured from a controller, a control circuit, etc., which are described based on a common understanding in the technical field to which this disclosure pertains.

The control unit 110 may control signal generation, scheduling (e.g., resource allocation, mapping), etc. The control unit 110 may control transmission and reception using the transceiver unit 120, the transceiver antenna 130, and the transmission path interface 140, measurement, etc. The control unit 110 may generate data, control information, sequences, etc. to be transmitted as signals, and transfer them to the transceiver unit 120. The control unit 110 may perform call processing of communication channels (setting, release, etc.), status management of the base station 10, management of radio resources, etc.

The transceiver unit 120 may include a baseband unit 121, a radio frequency (RF) unit 122, and a measurement unit 123. The baseband unit 121 may include a transmission processing unit 1211 and a reception processing unit 1212. The transceiver unit 120 may be composed of a transmitter/receiver, an RF circuit, a baseband circuit, a filter, a phase shifter, a measurement circuit, a transceiver circuit, etc., which are described based on a common understanding in the technical field to which the present disclosure relates.

The transceiver 120 may be configured as an integrated transceiver, or may be composed of a transmitter and a receiver. The transmitter may be composed of a transmission processing unit 1211 and an RF unit 122. The receiver may be composed of a reception processing unit 1212, an RF unit 122, and a measurement unit 123.

The transmitting/receiving antenna 130 can be configured as an antenna described based on common understanding in the technical field to which this disclosure pertains, such as an array antenna.

The transceiver 120 may transmit the above-mentioned downlink channel, synchronization signal, downlink reference signal, etc. The transceiver 120 may receive the above-mentioned uplink channel, uplink reference signal, etc.

The transceiver 120 may form at least one of the transmit beam and receive beam using digital beamforming (e.g., precoding), analog beamforming (e.g., phase rotation), etc.

The transceiver 120 (transmission processing unit 1211) may perform Packet Data Convergence Protocol (PDCP) layer processing, Radio Link Control (RLC) layer processing (e.g., RLC retransmission control), Medium Access Control (MAC) layer processing (e.g., HARQ retransmission control), etc. on data and control information obtained from the control unit 110 to generate a bit string to be transmitted.

The transceiver 120 (transmission processor 1211) may perform transmission processing such as channel coding (which may include error correction coding), modulation, mapping, filtering, Discrete Fourier Transform (DFT) processing (if necessary), Inverse Fast Fourier Transform (IFFT) processing, precoding, and digital-to-analog conversion on the bit string to be transmitted, and output a baseband signal.

The transceiver unit 120 (RF unit 122) may perform modulation, filtering, amplification, etc., on the baseband signal to a radio frequency band, and transmit the radio frequency band signal via the transceiver antenna 130.

On the other hand, the transceiver unit 120 (RF unit 122) may perform amplification, filtering, demodulation to a baseband signal, etc. on the radio frequency band signal received by the transceiver antenna 130.

The transceiver 120 (reception processing unit 1212) may apply reception processing such as analog-to-digital conversion, Fast Fourier Transform (FFT) processing, Inverse Discrete Fourier Transform (IDFT) processing (if necessary), filtering, demapping, demodulation, decoding (which may include error correction decoding), MAC layer processing, RLC layer processing, and PDCP layer processing to the acquired baseband signal, and acquire user data, etc.

The transceiver 120 (measurement unit 123) may perform measurements on the received signal. For example, the measurement unit 123 may perform Radio Resource Management (RRM) measurements, Channel State Information (CSI) measurements, etc. based on the received signal. The measurement unit 123 may measure received power (e.g., Reference Signal Received Power (RSRP)), received quality (e.g., Reference Signal Received Quality (RSRQ), Signal to Interference plus Noise Ratio (SINR), Signal to Noise Ratio (SNR)), signal strength (e.g., Received Signal Strength Indicator (RSSI)), propagation path information (e.g., CSI), etc. The measurement results may be output to the control unit 110.

The transmission path interface 140 may transmit and receive signals (backhaul signaling) between devices included in the core network 30 (e.g., network nodes providing NF), other base stations 10, etc., and may acquire and transmit user data (user plane data), control plane data, etc. for the user terminal 20.

Note that the transmitting section and receiving section of the base station 10 in this disclosure may be configured with at least one of the transmitting/receiving section 120, the transmitting/receiving antenna 130, and the transmission path interface 140.

The transceiver 120 may transmit settings related to a codebook for reporting channel state information (CSI).

The control unit 110 may control the reception of CSI reports using parameter values for an extended type 2 codebook or an extended type 2 port selection codebook for ranks or layers greater than 4 determined based on the settings.

(User terminal)
13 is a diagram showing an example of the configuration of a user terminal according to an embodiment. The user terminal 20 includes a control unit 210, a transceiver unit 220, and a transceiver antenna 230. Note that the control unit 210, the transceiver unit 220, and the transceiver antenna 230 may each include one or more.

Note that this example mainly shows the functional blocks of the characteristic parts of this embodiment, and the user terminal 20 may also be assumed to have other functional blocks necessary for wireless communication. Some of the processing of each part described below may be omitted.

The control unit 210 controls the entire user terminal 20. The control unit 210 can be configured from a controller, a control circuit, etc., which are described based on a common understanding in the technical field to which this disclosure pertains.

The control unit 210 may control signal generation, mapping, etc. The control unit 210 may control transmission and reception using the transceiver unit 220 and the transceiver antenna 230, measurement, etc. The control unit 210 may generate data, control information, sequences, etc. to be transmitted as signals, and transfer them to the transceiver unit 220.

The transceiver unit 220 may include a baseband unit 221, an RF unit 222, and a measurement unit 223. The baseband unit 221 may include a transmission processing unit 2211 and a reception processing unit 2212. The transceiver unit 220 may be composed of a transmitter/receiver, an RF circuit, a baseband circuit, a filter, a phase shifter, a measurement circuit, a transceiver circuit, etc., which are described based on a common understanding in the technical field to which the present disclosure relates.

The transceiver unit 220 may be configured as an integrated transceiver unit, or may be composed of a transmission unit and a reception unit. The transmission unit may be composed of a transmission processing unit 2211 and an RF unit 222. The reception unit may be composed of a reception processing unit 2212, an RF unit 222, and a measurement unit 223.

The transmitting/receiving antenna 230 can be configured as an antenna described based on common understanding in the technical field to which this disclosure pertains, such as an array antenna.

The transceiver 220 may receive the above-mentioned downlink channel, synchronization signal, downlink reference signal, etc. The transceiver 220 may transmit the above-mentioned uplink channel, uplink reference signal, etc.

The transceiver unit 220 may form at least one of the transmit beam and receive beam using digital beamforming (e.g., precoding), analog beamforming (e.g., phase rotation), etc.

The transceiver 220 (transmission processor 2211) may perform PDCP layer processing, RLC layer processing (e.g., RLC retransmission control), MAC layer processing (e.g., HARQ retransmission control), etc. on the data and control information acquired from the controller 210, and generate a bit string to be transmitted.

The transceiver 220 (transmission processor 2211) may perform transmission processing such as channel coding (which may include error correction coding), modulation, mapping, filtering, DFT processing (if necessary), IFFT processing, precoding, and digital-to-analog conversion on the bit string to be transmitted, and output a baseband signal.

Whether or not to apply DFT processing may be based on the settings of transform precoding. When transform precoding is enabled for a certain channel (e.g., PUSCH), the transceiver unit 220 (transmission processing unit 2211) may perform DFT processing as the above-mentioned transmission processing in order to transmit the channel using a DFT-s-OFDM waveform, and when transform precoding is not enabled, it is not necessary to perform DFT processing as the above-mentioned transmission processing.

The transceiver unit 220 (RF unit 222) may perform modulation, filtering, amplification, etc., on the baseband signal to a radio frequency band, and transmit the radio frequency band signal via the transceiver antenna 230.

On the other hand, the transceiver unit 220 (RF unit 222) may perform amplification, filtering, demodulation to a baseband signal, etc. on the radio frequency band signal received by the transceiver antenna 230.

The transceiver 220 (reception processor 2212) may apply reception processing such as analog-to-digital conversion, FFT processing, IDFT processing (if necessary), filtering, demapping, demodulation, decoding (which may include error correction decoding), MAC layer processing, RLC layer processing, and PDCP layer processing to the acquired baseband signal to acquire user data, etc.

The transceiver 220 (measurement unit 223) may perform measurements on the received signal. For example, the measurement unit 223 may perform RRM measurements, CSI measurements, etc. based on the received signal. The measurement unit 223 may measure received power (e.g., RSRP), received quality (e.g., RSRQ, SINR, SNR), signal strength (e.g., RSSI), propagation path information (e.g., CSI), etc. The measurement results may be output to the control unit 210.

The measurement unit 223 may derive channel measurements for CSI calculation based on channel measurement resources. The channel measurement resources may be, for example, non-zero power (NZP) CSI-RS resources. The measurement unit 223 may derive interference measurements for CSI calculation based on interference measurement resources. The interference measurement resources may be at least one of NZP CSI-RS resources for interference measurement, CSI-Interference Measurement (IM) resources, etc. CSI-IM may be called CSI-Interference Management (IM) or may be interchangeably read as Zero Power (ZP) CSI-RS. In this disclosure, CSI-RS, NZP CSI-RS, ZP CSI-RS, CSI-IM, CSI-SSB, etc. may be read as interchangeable.

In addition, the transmitting unit and receiving unit of the user terminal 20 in this disclosure may be configured by at least one of the transmitting/receiving unit 220 and the transmitting/receiving antenna 230.

The transceiver 220 may receive settings regarding a codebook for reporting channel state information (CSI).

The control unit 210 may determine parameter values for an extended type 2 codebook or an extended type 2 port selection codebook for ranks or layers greater than 4 for CSI reporting based on the settings.

The transceiver unit 220 may receive a first setting that allows reporting of ranks or layers greater than 4 or a second setting to enable an extension of the parameter setting table.

When the control unit 210 receives the first setting or the second setting, it may determine parameter values for the extended type 2 codebook or the extended type 2 port selection codebook for ranks or layers greater than 4.

The control unit 210 may select different spatial domain (SD) vectors or ports for different layers.

The control unit 210 may determine parameter values for the extended type 2 codebook or the extended type 2 port selection codebook using different tables depending on the rank or number of layers for the CSI report.

(Hardware configuration)
The block diagrams used in the description of the above embodiments show functional blocks. These functional blocks (components) are realized by any combination of at least one of hardware and software. The method of realizing each functional block is not particularly limited. That is, each functional block may be realized using one device that is physically or logically coupled, or may be realized using two or more devices that are physically or logically separated and directly or indirectly connected (for example, using wires, wirelessly, etc.). The functional blocks may be realized by combining the one device or the multiple devices with software.

Here, the functions include, but are not limited to, judgement, determination, judgment, calculation, computation, processing, derivation, investigation, search, confirmation, reception, transmission, output, access, resolution, selection, selection, establishment, comparison, assumption, expectation, deeming, broadcasting, notifying, communicating, forwarding, configuring, reconfiguring, allocating, mapping, and assignment. For example, a functional block (component) that performs the transmission function may be called a transmitting unit, a transmitter, and the like. In either case, as mentioned above, there are no particular limitations on the method of realization.

For example, a base station, a user terminal, etc. in one embodiment of the present disclosure may function as a computer that performs processing of the wireless communication method of the present disclosure. FIG. 14 is a diagram showing an example of the hardware configuration of a base station and a user terminal according to one embodiment. The above-mentioned base station 10 and user terminal 20 may be physically configured as a computer device including a processor 1001, a memory 1002, a storage 1003, a communication device 1004, an input device 1005, an output device 1006, a bus 1007, etc.

In addition, in this disclosure, terms such as apparatus, circuit, device, section, and unit may be interpreted as interchangeable. The hardware configurations of the base station 10 and the user terminal 20 may be configured to include one or more of the devices shown in the figures, or may be configured to exclude some of the devices.

For example, although only one processor 1001 is shown, there may be multiple processors. Furthermore, processing may be performed by one processor, or processing may be performed by two or more processors simultaneously, sequentially, or using other techniques. Furthermore, the processor 1001 may be implemented by one or more chips.

The functions of the base station 10 and the user terminal 20 are realized, for example, by loading specific software (programs) onto hardware such as the processor 1001 and memory 1002, causing the processor 1001 to perform calculations, control communications via the communication device 1004, and control at least one of the reading and writing of data in the memory 1002 and storage 1003.

The processor 1001, for example, operates an operating system to control the entire computer. The processor 1001 may be configured as a central processing unit (CPU) including an interface with peripheral devices, a control device, an arithmetic unit, registers, etc. For example, at least a portion of the above-mentioned control unit 110 (210), transmission/reception unit 120 (220), etc. may be realized by the processor 1001.

The processor 1001 also reads out programs (program codes), software modules, data, etc. from at least one of the storage 1003 and the communication device 1004 into the memory 1002, and executes various processes according to these. The programs used are those that cause a computer to execute at least some of the operations described in the above embodiments. For example, the control unit 110 (210) may be realized by a control program stored in the memory 1002 and running on the processor 1001, and similar implementations may be made for other functional blocks.

Memory 1002 is a computer-readable recording medium and may be composed of at least one of, for example, Read Only Memory (ROM), Erasable Programmable ROM (EPROM), Electrically EPROM (EEPROM), Random Access Memory (RAM), and other suitable storage media. Memory 1002 may also be called a register, cache, main memory, etc. Memory 1002 can store executable programs (program codes), software modules, etc. for implementing a wireless communication method according to one embodiment of the present disclosure.

Storage 1003 is a computer-readable recording medium and may be composed of at least one of a flexible disk, a floppy disk, a magneto-optical disk (e.g., a compact disk (Compact Disc ROM (CD-ROM)), a digital versatile disk, a Blu-ray disk), a removable disk, a hard disk drive, a smart card, a flash memory device (e.g., a card, a stick, a key drive), a magnetic stripe, a database, a server, or other suitable storage medium. Storage 1003 may also be referred to as an auxiliary storage device.

The communication device 1004 is hardware (transmitting/receiving device) for communicating between computers via at least one of a wired network and a wireless network, and is also called, for example, a network device, a network controller, a network card, a communication module, etc. The communication device 1004 may be configured to include a high-frequency switch, a duplexer, a filter, a frequency synthesizer, etc. to realize at least one of, for example, Frequency Division Duplex (FDD) and Time Division Duplex (TDD). For example, the above-mentioned transmitting/receiving unit 120 (220), transmitting/receiving antenna 130 (230), etc. may be realized by the communication device 1004. The transmitting/receiving unit 120 (220) may be implemented as a transmitting unit 120a (220a) and a receiving unit 120b (220b) that are physically or logically separated.

The input device 1005 is an input device (e.g., a keyboard, a mouse, a microphone, a switch, a button, a sensor, etc.) that accepts input from the outside. The output device 1006 is an output device (e.g., a display, a speaker, a Light Emitting Diode (LED) lamp, etc.) that performs output to the outside. Note that the input device 1005 and the output device 1006 may be integrated into one structure (e.g., a touch panel).

Furthermore, each device such as the processor 1001 and memory 1002 is connected by a bus 1007 for communicating information. The bus 1007 may be configured using a single bus, or may be configured using different buses between each device.

Furthermore, the base station 10 and the user terminal 20 may be configured to include hardware such as a microprocessor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a programmable logic device (PLD), or a field programmable gate array (FPGA), and some or all of the functional blocks may be realized using the hardware. For example, the processor 1001 may be implemented using at least one of these pieces of hardware.

(Modification)
In addition, the terms described in this disclosure and the terms necessary for understanding this disclosure may be replaced with terms having the same or similar meanings. For example, a channel, a symbol, and a signal (signal or signaling) may be read as mutually interchangeable. A signal may also be a message. A reference signal may be abbreviated as RS, and may be called a pilot, a pilot signal, or the like depending on the applied standard. A component carrier (CC) may also be called a cell, a frequency carrier, a carrier frequency, or the like.

A radio frame may be composed of one or more periods (frames) in the time domain. Each of the one or more periods (frames) constituting a radio frame may be called a subframe. Furthermore, a subframe may be composed of one or more slots in the time domain. A subframe may have a fixed time length (e.g., 1 ms) that is independent of numerology.

Here, the numerology may be a communication parameter that is applied to at least one of the transmission and reception of a signal or channel. The numerology may indicate, for example, at least one of the following: SubCarrier Spacing (SCS), bandwidth, symbol length, cyclic prefix length, Transmission Time Interval (TTI), number of symbols per TTI, radio frame configuration, a specific filtering process performed by the transceiver in the frequency domain, a specific windowing process performed by the transceiver in the time domain, etc.

A slot may consist of one or more symbols in the time domain (such as Orthogonal Frequency Division Multiplexing (OFDM) symbols, Single Carrier Frequency Division Multiple Access (SC-FDMA) symbols, etc.). A slot may also be a time unit based on numerology.

A slot may include multiple minislots. Each minislot may consist of one or multiple symbols in the time domain. A minislot may also be called a subslot. A minislot may consist of fewer symbols than a slot. A PDSCH (or PUSCH) transmitted in a time unit larger than a minislot may be called PDSCH (PUSCH) mapping type A. A PDSCH (or PUSCH) transmitted using a minislot may be called PDSCH (PUSCH) mapping type B.

A radio frame, subframe, slot, minislot, and symbol all represent time units when transmitting a signal. A different name may be used for radio frame, subframe, slot, minislot, and symbol. Note that the time units such as frame, subframe, slot, minislot, and symbol in this disclosure may be read as interchangeable.

For example, one subframe may be called a TTI, multiple consecutive subframes may be called a TTI, or one slot or one minislot may be called a TTI. In other words, at least one of the subframe and the TTI may be a subframe (1 ms) in existing LTE, a period shorter than 1 ms (e.g., 1-13 symbols), or a period longer than 1 ms. Note that the unit representing the TTI may be called a slot, minislot, etc., instead of a subframe.

Here, TTI refers to, for example, the smallest time unit for scheduling in wireless communication. For example, in an LTE system, a base station schedules each user terminal by allocating radio resources (such as frequency bandwidth and transmission power that can be used by each user terminal) in TTI units. Note that the definition of TTI is not limited to this.

The TTI may be a transmission time unit for a channel-coded data packet (transport block), a code block, a code word, etc., or may be a processing unit for scheduling, link adaptation, etc. When a TTI is given, the time interval (e.g., the number of symbols) in which a transport block, a code block, a code word, etc. is actually mapped may be shorter than the TTI.

Note that when one slot or one minislot is called a TTI, one or more TTIs (i.e., one or more slots or one or more minislots) may be the minimum time unit of scheduling. In addition, the number of slots (minislots) that constitute the minimum time unit of scheduling may be controlled.

A TTI having a time length of 1 ms may be called a normal TTI (TTI in 3GPP Rel. 8-12), normal TTI, long TTI, normal subframe, normal subframe, long subframe, slot, etc. A TTI shorter than a normal TTI may be called a shortened TTI, short TTI, partial or fractional TTI, shortened subframe, short subframe, minislot, subslot, slot, etc.

Note that a long TTI (e.g., a normal TTI, a subframe, etc.) may be interpreted as a TTI having a time length of more than 1 ms, and a short TTI (e.g., a shortened TTI, etc.) may be interpreted as a TTI having a TTI length shorter than the TTI length of a long TTI and equal to or greater than 1 ms.

A resource block (RB) is a resource allocation unit in the time domain and frequency domain, and may include one or more consecutive subcarriers in the frequency domain. The number of subcarriers included in an RB may be the same regardless of numerology, and may be, for example, 12. The number of subcarriers included in an RB may be determined based on numerology.

Furthermore, an RB may include one or more symbols in the time domain and may be one slot, one minislot, one subframe, or one TTI in length. One TTI, one subframe, etc. may each be composed of one or more resource blocks.

In addition, one or more RBs may be referred to as a physical resource block (PRB), a sub-carrier group (SCG), a resource element group (REG), a PRB pair, an RB pair, etc.

Furthermore, a resource block may be composed of one or more resource elements (REs). For example, one RE may be a radio resource area of one subcarrier and one symbol.

A Bandwidth Part (BWP), which may also be referred to as a partial bandwidth, may represent a subset of contiguous common resource blocks (RBs) for a given numerology on a given carrier, where the common RBs may be identified by an index of the RB relative to a common reference point of the carrier. PRBs may be defined in a BWP and numbered within the BWP.

The BWP may include a UL BWP (BWP for UL) and a DL BWP (BWP for DL). One or more BWPs may be configured for a UE within one carrier.

At least one of the configured BWPs may be active, and the UE may not expect to transmit or receive a given signal/channel outside the active BWP. Note that "cell," "carrier," etc. in this disclosure may be read as "BWP."

Note that the above-mentioned structures of radio frames, subframes, slots, minislots, and symbols are merely examples. For example, the number of subframes included in a radio frame, the number of slots per subframe or radio frame, the number of minislots included in a slot, the number of symbols and RBs included in a slot or minislot, the number of subcarriers included in an RB, as well as the number of symbols in a TTI, the symbol length, and the cyclic prefix (CP) length can be changed in various ways.

In addition, the information, parameters, etc. described in this disclosure may be represented using absolute values, may be represented using relative values from a predetermined value, or may be represented using other corresponding information. For example, a radio resource may be indicated by a predetermined index.

The names used for parameters and the like in this disclosure are not limiting in any respect. Furthermore, the formulas and the like using these parameters may differ from those explicitly disclosed in this disclosure. The various channels (PUCCH, PDCCH, etc.) and information elements may be identified by any suitable names, and the various names assigned to these various channels and information elements are not limiting in any respect.

The information, signals, etc. described in this disclosure may be represented using any of a variety of different technologies. For example, the data, instructions, commands, information, signals, bits, symbols, chips, etc. that may be referred to throughout the above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or magnetic particles, optical fields or photons, or any combination thereof.

In addition, information, signals, etc. may be output from a higher layer to a lower layer and/or from a lower layer to a higher layer. Information, signals, etc. may be input/output via multiple network nodes.

Input/output information, signals, etc. may be stored in a specific location (e.g., memory) or may be managed using a management table. Input/output information, signals, etc. may be overwritten, updated, or added to. Output information, signals, etc. may be deleted. Input information, signals, etc. may be transmitted to another device.

The notification of information is not limited to the aspects/embodiments described in this disclosure, and may be performed using other methods. For example, the notification of information in this disclosure may be performed by physical layer signaling (e.g., Downlink Control Information (DCI), Uplink Control Information (UCI)), higher layer signaling (e.g., Radio Resource Control (RRC) signaling, broadcast information (Master Information Block (MIB), System Information Block (SIB)), etc.), Medium Access Control (MAC) signaling), other signals, or a combination of these.

The physical layer signaling may be called Layer 1/Layer 2 (L1/L2) control information (L1/L2 control signal), L1 control information (L1 control signal), etc. The RRC signaling may be called an RRC message, for example, an RRC Connection Setup message, an RRC Connection Reconfiguration message, etc. The MAC signaling may be notified, for example, using a MAC Control Element (CE).

Furthermore, notification of specified information (e.g., notification that "X is the case") is not limited to explicit notification, but may be implicit (e.g., by not notifying the specified information or by notifying other information).

The determination may be based on a value represented by a single bit (0 or 1), a Boolean value represented by true or false, or a comparison of numerical values (e.g., with a predetermined value).

Software shall be construed broadly to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software modules, applications, software applications, software packages, routines, subroutines, objects, executable files, threads of execution, procedures, functions, etc., whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise.

Software, instructions, information, etc. may also be transmitted and received via a transmission medium. For example, if the software is transmitted from a website, server, or other remote source using at least one of wired technologies (such as coaxial cable, fiber optic cable, twisted pair, Digital Subscriber Line (DSL)), and/or wireless technologies (such as infrared, microwave, etc.), then at least one of these wired and wireless technologies is included within the definition of a transmission medium.

As used in this disclosure, the terms "system" and "network" may be used interchangeably. "Network" may refer to the devices included in the network (e.g., base stations).

In this disclosure, terms such as "precoding", "precoder", "weight (precoding weight)", "Quasi-Co-Location (QCL)", "Transmission Configuration Indication state (TCI state)", "spatial relation", "spatial domain filter", "transmit power", "phase rotation", "antenna port", "layer", "number of layers", "rank", "resource", "resource set", "beam", "beam width", "beam angle", "antenna", "antenna element", "panel", "UE panel", "transmitting entity", "receiving entity", etc. may be used interchangeably.

In the present disclosure, the antenna port may be interchangeably read as an antenna port for any signal/channel (e.g., a demodulation reference signal (DMRS) port). In the present disclosure, the resource may be interchangeably read as a resource for any signal/channel (e.g., a reference signal resource, an SRS resource, etc.). The resource may include time/frequency/code/space/power resources. The spatial domain transmission filter may include at least one of a spatial domain transmission filter and a spatial domain reception filter.

The above groups may include, for example, at least one of a spatial relationship group, a Code Division Multiplexing (CDM) group, a Reference Signal (RS) group, a Control Resource Set (CORESET) group, a PUCCH group, an antenna port group (e.g., a DMRS port group), a layer group, a resource group, a beam group, an antenna group, a panel group, etc.

Furthermore, in this disclosure, beam, SRS Resource Indicator (SRI), CORESET, CORESET pool, PDSCH, PUSCH, codeword (CW), transport block (TB), RS, etc. may be read as interchangeable.

Furthermore, in this disclosure, the terms TCI state, downlink TCI state (DL TCI state), uplink TCI state (UL TCI state), unified TCI state, common TCI state, joint TCI state, etc. may be interpreted as interchangeable.

Furthermore, in this disclosure, "QCL", "QCL assumptions", "QCL relationship", "QCL type information", "QCL property/properties", "specific QCL type (e.g., Type A, Type D) characteristics", "specific QCL type (e.g., Type A, Type D)", etc. may be read as interchangeable.

In this disclosure, the terms index, identifier (ID), indicator, indication, resource ID, etc. may be interchangeable. In this disclosure, the terms sequence, list, set, group, cluster, subset, etc. may be interchangeable.

Furthermore, the spatial relationship information identifier (ID) (TCI state ID) and the spatial relationship information (TCI state) may be interchangeable. "Spatial relationship information (TCI state)" may be interchangeable as "set of spatial relationship information (TCI state)", "one or more pieces of spatial relationship information", etc. TCI state and TCI may be interchangeable. Spatial relationship information and spatial relationship may be interchangeable.

In this disclosure, terms such as "Base Station (BS)", "Radio base station", "Fixed station", "NodeB", "eNB (eNodeB)", "gNB (gNodeB)", "Access point", "Transmission Point (TP)", "Reception Point (RP)", "Transmission/Reception Point (TRP)", "Panel", "Cell", "Sector", "Cell group", "Carrier", "Component carrier", etc. may be used interchangeably. Base stations may also be referred to by terms such as macrocell, small cell, femtocell, picocell, etc.

A base station can accommodate one or more (e.g., three) cells. When a base station accommodates multiple cells, the entire coverage area of the base station can be divided into multiple smaller areas, and each smaller area can also provide communication services by a base station subsystem (e.g., a small base station for indoor use (Remote Radio Head (RRH))). The term "cell" or "sector" refers to a part or the entire coverage area of at least one of the base station and base station subsystems that provide communication services in this coverage.

In this disclosure, a base station transmitting information to a terminal may be interpreted as the base station instructing the terminal to control/operate based on the information.

In this disclosure, the terms "Mobile Station (MS)", "user terminal", "User Equipment (UE)", "terminal", etc. may be used interchangeably.

A mobile station may also be referred to as a subscriber station, mobile unit, subscriber unit, wireless unit, remote unit, mobile device, wireless device, wireless communication device, remote device, mobile subscriber station, access terminal, mobile terminal, wireless terminal, remote terminal, handset, user agent, mobile client, client, or some other suitable terminology.

At least one of the base station and the mobile station may be called a transmitting device, a receiving device, a wireless communication device, etc. In addition, at least one of the base station and the mobile station may be a device mounted on a moving object, the moving object itself, etc.

The moving body in question refers to an object that can move, and the moving speed is arbitrary, and of course includes the case where the moving body is stationary. The moving body in question includes, but is not limited to, vehicles, transport vehicles, automobiles, motorcycles, bicycles, connected cars, excavators, bulldozers, wheel loaders, dump trucks, forklifts, trains, buses, handcarts, rickshaws, ships and other watercraft, airplanes, rockets, artificial satellites, drones, multicopters, quadcopters, balloons, and objects mounted on these. The moving body in question may also be a moving body that moves autonomously based on an operating command.

The moving object may be a vehicle (e.g., a car, an airplane, etc.), an unmanned moving object (e.g., a drone, an autonomous vehicle, etc.), or a robot (manned or unmanned). Note that at least one of the base station and the mobile station may also include devices that do not necessarily move during communication operations. For example, at least one of the base station and the mobile station may be an Internet of Things (IoT) device such as a sensor.

FIG. 15 is a diagram showing an example of a vehicle according to an embodiment. The vehicle 40 includes a drive unit 41, a steering unit 42, an accelerator pedal 43, a brake pedal 44, a shift lever 45, left and right front wheels 46, left and right rear wheels 47, an axle 48, an electronic control unit 49, various sensors (including a current sensor 50, a rotation speed sensor 51, an air pressure sensor 52, a vehicle speed sensor 53, an acceleration sensor 54, an accelerator pedal sensor 55, a brake pedal sensor 56, a shift lever sensor 57, and an object detection sensor 58), an information service unit 59, and a communication module 60.

The drive unit 41 is composed of at least one of an engine, a motor, and a hybrid of an engine and a motor, for example. The steering unit 42 includes at least a steering wheel (also called a handlebar), and is configured to steer at least one of the front wheels 46 and the rear wheels 47 based on the operation of the steering wheel operated by the user.

The electronic control unit 49 is composed of a microprocessor 61, memory (ROM, RAM) 62, and a communication port (e.g., an Input/Output (IO) port) 63. Signals are input to the electronic control unit 49 from various sensors 50-58 provided in the vehicle. The electronic control unit 49 may also be called an Electronic Control Unit (ECU).

Signals from the various sensors 50-58 include a current signal from a current sensor 50 that senses the motor current, a rotation speed signal of the front wheels 46/rear wheels 47 acquired by a rotation speed sensor 51, an air pressure signal of the front wheels 46/rear wheels 47 acquired by an air pressure sensor 52, a vehicle speed signal acquired by a vehicle speed sensor 53, an acceleration signal acquired by an acceleration sensor 54, a depression amount signal of the accelerator pedal 43 acquired by an accelerator pedal sensor 55, a depression amount signal of the brake pedal 44 acquired by a brake pedal sensor 56, an operation signal of the shift lever 45 acquired by a shift lever sensor 57, and a detection signal for detecting obstacles, vehicles, pedestrians, etc. acquired by an object detection sensor 58.

The information service unit 59 is composed of various devices, such as a car navigation system, audio system, speakers, displays, televisions, and radios, for providing (outputting) various information such as driving information, traffic information, and entertainment information, and one or more ECUs that control these devices. The information service unit 59 uses information acquired from external devices via the communication module 60, etc., to provide various information/services (e.g., multimedia information/multimedia services) to the occupants of the vehicle 40.

The information service unit 59 may include input devices (e.g., a keyboard, a mouse, a microphone, a switch, a button, a sensor, a touch panel, etc.) that accept input from the outside, and may also include output devices (e.g., a display, a speaker, an LED lamp, a touch panel, etc.) that perform output to the outside.

The driving assistance system unit 64 is composed of various devices that provide functions for preventing accidents and reducing the driver's driving load, such as a millimeter wave radar, a Light Detection and Ranging (LiDAR), a camera, a positioning locator (e.g., a Global Navigation Satellite System (GNSS)), map information (e.g., a High Definition (HD) map, an Autonomous Vehicle (AV) map, etc.), a gyro system (e.g., an Inertial Measurement Unit (IMU), an Inertial Navigation System (INS), etc.), an Artificial Intelligence (AI) chip, and an AI processor, and one or more ECUs that control these devices. The driving assistance system unit 64 also transmits and receives various information via the communication module 60 to realize a driving assistance function or an autonomous driving function.

The communication module 60 can communicate with the microprocessor 61 and components of the vehicle 40 via the communication port 63. For example, the communication module 60 transmits and receives data (information) via the communication port 63 between the drive unit 41, steering unit 42, accelerator pedal 43, brake pedal 44, shift lever 45, left and right front wheels 46, left and right rear wheels 47, axles 48, the microprocessor 61 and memory (ROM, RAM) 62 in the electronic control unit 49, and the various sensors 50-58 that are provided on the vehicle 40.

The communication module 60 is a communication device that can be controlled by the microprocessor 61 of the electronic control unit 49 and can communicate with an external device. For example, it transmits and receives various information to and from the external device via wireless communication. The communication module 60 may be located either inside or outside the electronic control unit 49. The external device may be, for example, the above-mentioned base station 10 or user terminal 20. The communication module 60 may also be, for example, at least one of the above-mentioned base station 10 and user terminal 20 (it may function as at least one of the base station 10 and user terminal 20).

The communication module 60 may transmit at least one of the signals from the various sensors 50-58 described above input to the electronic control unit 49, information obtained based on the signals, and information based on input from the outside (user) obtained via the information service unit 59 to an external device via wireless communication. The electronic control unit 49, the various sensors 50-58, the information service unit 59, etc. may be referred to as input units that accept input. For example, the PUSCH transmitted by the communication module 60 may include information based on the above input.

The communication module 60 receives various information (traffic information, signal information, vehicle distance information, etc.) transmitted from an external device and displays it on an information service unit 59 provided in the vehicle. The information service unit 59 may also be called an output unit that outputs information (for example, outputs information to a device such as a display or speaker based on the PDSCH (or data/information decoded from the PDSCH) received by the communication module 60).

The communication module 60 also stores various information received from external devices in memory 62 that can be used by the microprocessor 61. Based on the information stored in memory 62, the microprocessor 61 may control the drive unit 41, steering unit 42, accelerator pedal 43, brake pedal 44, shift lever 45, left and right front wheels 46, left and right rear wheels 47, axles 48, various sensors 50-58, and the like provided on the vehicle 40.

Furthermore, the base station in the present disclosure may be read as a user terminal. For example, each aspect/embodiment of the present disclosure may be applied to a configuration in which communication between a base station and a user terminal is replaced with communication between multiple user terminals (which may be called, for example, Device-to-Device (D2D), Vehicle-to-Everything (V2X), etc.). In this case, the user terminal 20 may be configured to have the functions of the base station 10 described above. Furthermore, terms such as "uplink" and "downlink" may be read as terms corresponding to terminal-to-terminal communication (for example, "sidelink"). For example, the uplink channel, downlink channel, etc. may be read as the sidelink channel.

Similarly, the user terminal in this disclosure may be interpreted as a base station. In this case, the base station 10 may be configured to have the functions of the user terminal 20 described above.

In this disclosure, operations that are described as being performed by a base station may in some cases be performed by its upper node. In a network that includes one or more network nodes having base stations, it is clear that various operations performed for communication with terminals may be performed by the base station, one or more network nodes other than the base station (such as, but not limited to, a Mobility Management Entity (MME) or a Serving-Gateway (S-GW)), or a combination of these.

Each aspect/embodiment described in this disclosure may be used alone, in combination, or switched between depending on the implementation. In addition, the processing procedures, sequences, flow charts, etc. of each aspect/embodiment described in this disclosure may be rearranged as long as there is no inconsistency. For example, the methods described in this disclosure present elements of various steps in an exemplary order, and are not limited to the particular order presented.

Each aspect/embodiment described in this disclosure includes Long Term Evolution (LTE), LTE-Advanced (LTE-A), LTE-Beyond (LTE-B), SUPER 3G, IMT-Advanced, 4th generation mobile communication system (4G), 5th generation mobile communication system (5G), 6th generation mobile communication system (6G), xth generation mobile communication system (xG (x is, for example, an integer or decimal)), Future Radio Access (FRA), New-Radio The present invention may be applied to systems that use Access Technology (RAT), New Radio (NR), New radio access (NX), Future generation radio access (FX), Global System for Mobile communications (GSM (registered trademark)), CDMA2000, Ultra Mobile Broadband (UMB), IEEE 802.11 (Wi-Fi (registered trademark)), IEEE 802.16 (WiMAX (registered trademark)), IEEE 802.20, Ultra-Wide Band (UWB), Bluetooth (registered trademark), and other appropriate wireless communication methods, as well as next-generation systems that are expanded, modified, created, or defined based on these. In addition, multiple systems may be combined (for example, a combination of LTE or LTE-A and 5G, etc.).

As used in this disclosure, the phrase "based on" does not mean "based only on," unless expressly stated otherwise. In other words, the phrase "based on" means both "based only on" and "based at least on."

Any reference to an element using a designation such as "first," "second," etc., used in this disclosure does not generally limit the quantity or order of those elements. These designations may be used in this disclosure as a convenient method of distinguishing between two or more elements. Thus, a reference to a first and second element does not imply that only two elements may be employed or that the first element must precede the second element in some way.

The term "determining" as used in this disclosure may encompass a wide variety of actions. For example, "determining" may be considered to be judging, calculating, computing, processing, deriving, investigating, looking up, search, inquiry (e.g., looking in a table, database, or other data structure), ascertaining, etc.

"Determining" may also be considered to mean "determining" receiving (e.g., receiving information), transmitting (e.g., sending information), input, output, accessing (e.g., accessing data in a memory), etc.

Furthermore, "judgment (decision)" may be considered to mean "judging (deciding)" resolving, selecting, choosing, establishing, comparing, etc. In other words, "judgment (decision)" may be considered to mean "judging (deciding)" some kind of action. In this disclosure, "judgment (decision)" may be read as interchangeably with the actions described above.

Furthermore, in this disclosure, "determine/determining" may be interpreted interchangeably as "assume/assuming," "expect/expecting," "consider/considering," etc. Furthermore, in this disclosure, "does not expect to do..." may be interpreted interchangeably as "assumes not to do...."

In the present disclosure, "expect" may be read as "be expected". For example, "expect(s) ..." ("..." may be expressed, for example, as a that clause, a to infinitive, etc.) may be read as "be expected ...". "does not expect ..." may be read as "be not expected ...". Also, "An apparatus A is not expected ..." may be read as "An apparatus B other than apparatus A does not expect ..." (for example, if apparatus A is a UE, apparatus B may be a base station).

The "maximum transmit power" referred to in this disclosure may mean the maximum value of transmit power, may mean the nominal UE maximum transmit power, or may mean the rated UE maximum transmit power.

As used in this disclosure, the terms "connected" and "coupled," or any variation thereof, refer to any direct or indirect connection or coupling between two or more elements, and may include the presence of one or more intermediate elements between two elements that are "connected" or "coupled" to each other. The coupling or connection between the elements may be physical, logical, or a combination thereof. For example, "connected" may be read as "access."

In this disclosure, when two elements are connected, they may be considered to be "connected" or "coupled" to one another using one or more wires, cables, printed electrical connections, and the like, as well as using electromagnetic energy having wavelengths in the radio frequency range, microwave range, light (both visible and invisible) range, and the like, as some non-limiting and non-exhaustive examples.

In this disclosure, the term "A and B are different" may mean "A and B are different from each other." The term may also mean "A and B are each different from C." Terms such as "separate" and "combined" may also be interpreted in the same way as "different."

When the terms "include," "including," and variations thereof are used in this disclosure, these terms are intended to be inclusive, similar to the term "comprising." Additionally, the term "or," as used in this disclosure, is not intended to be an exclusive or.

In this disclosure, where articles have been added through translation, such as a, an, and the in English, this disclosure may include that the nouns following these articles are plural.

In this disclosure, terms such as "less than", "less than", "greater than", "more than", "equal to", etc. may be read as interchangeable. In addition, in this disclosure, terms meaning "good", "bad", "big", "small", "high", "low", "fast", "slow", "wide", "narrow", etc. may be read as interchangeable, not limited to positive, comparative and superlative. In addition, in this disclosure, terms meaning "good", "bad", "big", "small", "high", "low", "fast", "slow", "wide", "narrow", etc. may be read as interchangeable, not limited to positive, comparative and superlative, as expressions with "ith" (i is any integer) (for example, "best" may be read as "ith best").

In this disclosure, the terms "of," "for," "regarding," "related to," "associated with," etc. may be read interchangeably.

In the present disclosure, "when A, B", "if A, (then) B", "B upon A", "B in response to A", "B based on A", "B during/while A", "B before A", "B at (the same time as)/on A", "B after A", "B since A", "B until A" and the like may be read as interchangeable. Note that A, B, etc. here may be replaced with appropriate expressions such as nouns, gerunds, and normal sentences depending on the context. Note that the time difference between A and B may be almost 0 (immediately after or immediately before). Also, a time offset may be applied to the time when A occurs. For example, "A" may be read interchangeably as "before/after the time offset at which A occurs." The time offset (e.g., one or more symbols/slots) may be predefined or may be identified by the UE based on signaled information.

In this disclosure, timing, time, duration, time instance, any time unit (e.g., slot, subslot, symbol, subframe), period, occasion, resource, etc. may be interpreted as interchangeable.

The invention disclosed herein has been described in detail above, but it is clear to those skilled in the art that the invention disclosed herein is not limited to the embodiments described herein. The description of the present disclosure is intended for illustrative purposes only and does not imply any limitations on the invention disclosed herein.

Claims (6)

a receiver for receiving a configuration regarding a codebook for channel state information (CSI) reporting;
a control unit that determines, based on the configuration, values of parameters for an extended type-2 codebook for ranks or layers greater than 4 for CSI reporting;
A terminal having the above configuration. The receiver receives a second setting for enabling an extension of a first setting or a parameter setting table to allow reporting of ranks or layers greater than four;
The terminal of claim 1 , wherein the control unit is configured to determine, when receiving the first configuration or the second configuration, values of parameters for an extended type-2 codebook for ranks or layers greater than 4. The terminal of claim 1 , wherein the control unit selects different spatial domain (SD) vectors for different layers. The terminal of claim 1 , wherein the controller determines values of parameters for the extended type-2 codebook using different tables depending on the number of ranks or layers for the CSI report. receiving a configuration regarding a codebook for channel state information (CSI) reporting;
determining, based on the configuration, values of parameters for an extended type-2 codebook for ranks or layers greater than 4 for CSI reporting;
A wireless communication method for a terminal having the above configuration. a transmitter for transmitting a configuration regarding a codebook for channel state information (CSI) reporting;
a control unit for controlling reception of a CSI report using a value of a parameter for an extended type-2 codebook for a rank or layer greater than 4 determined based on the configuration;
A base station having

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