Terminal, wireless communication method and system

Abstract

A terminal according to one embodiment of the present disclosure comprises: a reception unit that receives, for a channel state information reference signal, at least one among information related to a time domain resource indicated in a time unit longer than a slot and information related to a frequency domain resource supporting at least a frequency domain density of less than 0.5; and a control unit that controls reception of the channel state information reference signal on the basis of at least one among the information related to the time domain resource and the information related to the frequency domain resource.

Description

[Technical Field]

[0001] The present disclosure relates to a terminal, a wireless communication method, and a system Regarding. [Background technology]

[0002] In Universal Mobile Telecommunications System (UMTS) networks, Long Term Evolution (LTE) was specified with the aim of achieving higher data rates and lower latency (Non-Patent Document 1). Also, LTE-Advanced (3GPP Rel. 10-14) was specified with the aim of achieving higher capacity and more advanced features than LTE (Third Generation Partnership Project (3GPP) Release (Rel.) 8, 9).

[0003] 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 or later) are also being considered. [Prior art documents] [Non-patent literature]

[0004] [Non-Patent Document 1] 3GPP TS 36.300 V8.12.0 “Evolved Universal Terrestrial Radio Access (E-UTRA) and Evolved Universal Terrestrial Radio Access Network (E-UTRAN); Overall description; Stage 2 (Release 8)”, April 2010 Summary of the Invention [Problem to be solved by the invention]

[0005] Regarding future wireless communication technologies, the use of artificial intelligence (AI) techniques such as machine learning (ML) for network / device control and management is being considered. For example, the use of AI / ML complementation to reduce reference signal (RS) resources is being considered.

[0006] However, the specifics of the RS resource reduction have not yet been fully explored. Unless these are properly defined, highly efficient resource utilization cannot be achieved, and there is a risk that improvements in communication throughput or communication quality will be hindered.

[0007] Therefore, the present disclosure provides a terminal, a wireless communication method, and system One of the aims is to provide [Means for solving the problem]

[0008] A terminal according to an aspect of the present disclosure receives a channel state information reference signal. About ,information about time domain resources indicated in time units longer than a slot; Regarding the channel state information reference signal, and information about a frequency domain resource supporting a frequency domain density at least less than 0.5. The signal is measured, the results of the measurement are machine-learned, and channel estimation is performed using the completion by the machine learning. and a control unit for controlling the [Effects of the Invention]

[0009] According to one aspect of the present disclosure, it is possible to realize optimal utilization of RS resources. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a diagram illustrating an example of a resource mapping pattern for CSI-RS. [Figure 2] FIG. 2 is a diagram illustrating an example of higher layer parameters related to CSI-RS resource mapping information. [Figure 3] FIG. 3 is a diagram showing an example of CSI-RS locations within slots and RBs. [Figure 4] 4A and 4B are diagrams illustrating an example of CSI-RS resource mapping for a particular CSI-RS location configuration (eg, row). [Figure 5] FIG. 5 is a diagram illustrating another example of CSI-RS resource mapping for a particular CSI-RS location configuration (eg, row). [Figure 6] 6A to 6C are diagrams illustrating an example of CSI-RS resource mapping according to aspect 2-1 of the second embodiment. [Figure 7] FIG. 7 is a diagram illustrating an example of a method for indicating RB positions of CSI-RS resources according to aspect 2-1 of the second embodiment. [Figure 8] 8A to 8C are diagrams illustrating an example of CSI-RS resource mapping according to aspect 2-2 of the second embodiment. [Figure 9] 9A and 9B are diagrams illustrating another example of CSI-RS resource mapping according to aspect 2-2 of the second embodiment. [Figure 10] 10A and 10B are diagrams illustrating another example of CSI-RS resource mapping according to aspect 2-2 of the second embodiment. [Figure 11] 11A and 11B are diagrams illustrating another example of CSI-RS resource mapping according to aspect 2-2 of the second embodiment. [Figure 12] FIG. 12 is a diagram showing the configuration of a specific CSI-RS position (for example, row) according to aspect 2-2 of the second embodiment. [Figure 13] FIG. 13 is a diagram illustrating another example of CSI-RS resource mapping according to aspect 2-2 of the second embodiment. [Figure 14] 14A and 14B are diagrams illustrating an example of CSI-RS resource mapping according to a combination of aspect 2-1 and aspect 2-2 of the second embodiment. [Figure 15] 15A and 15B are diagrams showing another example of CSI-RS resource mapping according to a combination of aspect 2-1 and aspect 2-2 of the second embodiment. [Figure 16] 16A and 16B are diagrams illustrating an example of CSI-RS resource mapping according to aspect 2-3 of the second embodiment. [Figure 17] FIG. 17 is a diagram illustrating an example of higher layer parameters related to CSI-RS resource mapping information according to aspect 2-3 of the second embodiment. [Figure 18] 18A to 18D are diagrams illustrating other examples of CSI-RS resource mapping according to aspect 2-3 of the second embodiment. [Figure 19] 19A and 19B are diagrams illustrating another example of CSI-RS resource mapping according to aspect 2-3 of the second embodiment. [Figure 20] 20A and 20B are diagrams illustrating an example of CSI-RS resource mapping according to a combination of aspect 2-2 and aspect 2-3 of the second embodiment. [Figure 21] 21A and 21B are diagrams illustrating an example of CSI-RS resource mapping according to a combination of aspect 2-1, aspect 2-2, and aspect 2-3 of the second embodiment. [Figure 22] FIG. 22 is a diagram illustrating an example of a schematic configuration of a wireless communication system according to an embodiment. [Figure 23] FIG. 23 is a diagram illustrating an example of the configuration of a base station according to an embodiment. [Figure 24] FIG. 24 is a diagram illustrating an example of the configuration of a user terminal according to an embodiment. [Figure 25] FIG. 25 is a diagram illustrating an example of the hardware configuration of a base station and a user terminal according to an embodiment. [Figure 26] FIG. 26 is a diagram illustrating an example of a vehicle according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] (CSI-RS) In Rel. 15 / 16 NR, for example, the CSI-RS is used as a DL RS for at least one of channel state information (CSI) acquisition, beam management (BM), beam failure recovery (BFR), and fine time and frequency tracking.

[0012] In Rel.15 / 16 NR, multiple CSI-RS ports are multiplexed using at least one of frequency division multiplexing (FDM), time division multiplexing (TDM), and code division multiplexing (CDM (frequency domain OCC, time domain OCC)). CSI-RS supports up to 32 ports.

[0013] The multiple-port CSI-RS is used, for example, for orthogonalizing multi-input multi-output (MIMO) layers. For example, for single-user MIMO, a different DMRS port is configured for each layer. For multi-user MIMO, a different DMRS port is configured for each layer within one UE and for each UE.

[0014] In Rel.15 / 16 NR, CSI-RS supports up to 32 ports using at least one of time-domain OCC and frequency-domain OCC (up to 4 in the time direction and up to 2 in the frequency direction), FDM, and TDM. CSI-RS supports periodic, semi-persistent, and aperiodic transmission. The frequency density of CSI-RS is configurable to adjust overhead and CSI estimation accuracy.

[0015] <Time domain of CSI-RS> Periodic / semi-persistent CSI-RS has a predetermined periodicity (e.g., Periodicity) set. Prior to Rel.16 NR, the predetermined periodicity was set in slot units, specifically, any of 4 / 5 / 8 / 10 / 16 / 20 / 32 / 40 / 64 / 80 / 160 / 320 / 640 slots was set. In the case of aperiodic CSI-RS, all aperiodic CSI-RS resources within the same resource set are transmitted in the same slot.

[0016] <Resource mapping pattern of CSI-RS> In Rel.15 / 16 NR, CSI-RS supports 1, 2, 4, 8, 12, 16, 24, 32 ports (antenna ports, CSI-RS ports). Also, CSI-RS supports 3, 1, 0.5 as the frequency domain density (e.g., frequency domain density).

[0017] As the CDM type of CSI-RS, it supports non-CDM (e.g., no CDM) type and CDM type. As the CDM type, fd-CDM2, cdm4-FD2-TD2, cdm8-FD2-TD4 are supported (see Figure 1). fd-CDM2 multiplexes 2-port CSI-RS at the same time and frequency by multiplying a frequency domain (FD)-orthogonal cover code (orthogonal cover code (OCC)) of length 2 in RE units (FD2). cdm4 multiplexes 4-port CSI-RS at the same time and frequency by multiplying an FD-OCC of length 2 and a time domain (TD)-OCC of length 2 in RE unit symbol units (cdm4-FD2-TD2). cdm8 multiplexes 8-port CSI-RS at the same time and frequency by multiplying an FD-OCC of length 2 and a TD-OCC of length 4 in RE unit symbol units (cdm8-FD2-TD4).

[0018] CSI-RS supports one or two starting symbols in one slot as OFDM symbol allocation, and supports allocation of 1 / 2 / 4 adjacent symbols from each starting symbol.

[0019] The frequency-domain allocation of the CSI-RS may be indicated by a bitmap (e.g., bitmap indication). For example, the frequency-domain location of the CSI-RS may be determined based on a bitmap provided by a higher layer parameter related to CSI-RS resources (e.g., frequencyDomainAllocation) and a predetermined value (e.g., k i ). The frequencyDomainAllocation may be included in a higher layer parameter related to CSI-RS resource mapping (e.g., CSI-RS-ResourceMapping IE (see FIG. 2) or CSI-RS-ResourceConfigMobility IE).

[0020] The predetermined value (eg, k i ) related to the frequency location of the CSI-RS (eg, CDM group) within a slot may be a value defined in a table related to CSI-RS locations (see FIG. 3).

[0021] 3 is a diagram showing an example of the location of CSI-RS within a slot. Each row in the table indicates the row number, the number of ports, the frequency domain density, the CDM type, the time and frequency (time / frequency) location (the location of the component resource (CDM group) (k bar, l bar)), the CDM group index, and the location of each resource within the component resource ((RE, symbol), (k', l')). Here, the time / frequency location is the location of the time and frequency resource (component resource) of the CSI-RS corresponding to one port. The k bar is represented by an overlined "k." The k bar indicates the starting resource element (RE) index of the component resource, and the l bar indicates the starting symbol (OFDM symbol) index of the component resource.

[0022] In each row of the CSI-RS location table shown in FIG. 3, the following relationships may be defined: Row 1 (row#1):[b3…b0],k i-1 =f(i) Row 2 (row#2):[b11...b0],k i-1 =f(i) Row 4 (row#4):[b2...b0],k i-1 =4f(i) Other rows (cases other than row#1 / #2 / #4): [b5……b0], k i-1 =2f(i) f(i) denotes the number of the i-th bit in a bitmap (e.g., frequencyDomainAllocation) that is set to 1, and is repeated every 1 / ρ ceiling function (e.g., ceil(1 / ρ)) among the resource blocks configured for CSI-RS reception by the UE.

[0023] For example, Figure 4A shows an example of the CSI-RS location corresponding to row #1, where the number of ports is 1, the density is 3, and there is no CDM.

[0024] FIG. 4B shows an example of CSI-RS positions corresponding to row 4 (row #4). This example shows a case where the number of ports is 4, the density is 1, and fd-CDM2 is used. In the frequency domain and time domain of 1 PRB x 1 slot, two component resources of 2 subcarriers x 1 symbol are multiplexed (FDM) in the frequency domain and multiplexed once in the time domain, thereby mapping 2 x 1 component resources. Furthermore, the CSI-RS in each component resource is multiplied by an FD-OCC with a length of 2 subcarriers, thereby multiplexing (CDM) two CSI-RS. The CSI-RS includes two CDM groups. For example, the first CDM group (CDM group #0) includes two ports (e.g., port 3000, port 3001), and the second CDM group (CDM group #1) includes two ports (e.g., port 3002, port 3003).

[0025] FIG. 5 shows an example of a CSI-RS position corresponding to row #17. Here, the case is shown where the number of ports is 32, the density is 1 (or 0.5), and cdm4-FD2-TD2. In the frequency domain and time domain of 1 PRB x 1 slot, 4 component resources of 2 subcarriers x 2 symbols are multiplexed (FDM) in the frequency domain and 2 component resources are multiplexed (TDM) in the time domain, thereby mapping 4 x 2 component resources. Furthermore, the CSI-RS in each component resource is multiplied by a 2-subcarrier FD-OCC and a 2-symbol TD-OCC, thereby multiplexing (CDM) the four CSI-RS. The CSI-RS includes 8 CDM groups, and each CDM group includes 4 ports.

[0026] (Application of Artificial Intelligence (AI) technology to wireless communications) Regarding future wireless communication technologies, the use of AI technology for network / device control and management is being considered.

[0027] For example, in future wireless communication technologies, particularly in communications using beams, there is a demand for high accuracy in channel estimation (which may also be called channel measurement) for beam management, decoding of received signals, and the like.

[0028] Channel estimation may be performed using at least one of, for example, a Channel State Information Reference Signal (CSI-RS), a Synchronization Signal (SS), a Synchronization Signal / Physical Broadcast Channel (SS / PBCH) block, a Demodulation Reference Signal (DMRS), a Sounding Reference Signal (SRS), etc.

[0029] Regarding future wireless communication technologies, the use of artificial intelligence (AI) technologies such as machine learning (ML) for network / device control and management is being considered.

[0030] For example, AI / ML complementation is being considered to reduce reference signal (RS) resources while maintaining channel estimation accuracy.

[0031] For example, if AI / ML-based learning has not been performed (or completed) in a terminal (user terminal, also known as User Equipment (UE)) or base station, the following requirements may be necessary to achieve RS reception measurements that enable high channel estimation accuracy or accurate RS reception measurements used for learning: - Transmitting and receiving RS in a wide band (contributing to improved reception quality), Repeatedly transmitting RS to combine received channels / signals (composite reception) at the receiving side (contributes to improved reception quality), · High time / frequency density of RS resources (contributes to obtaining good time / frequency correlation).

[0032] Considering these factors, it is thought that the appropriate allocation of RS will differ depending on whether AI / ML has been sufficiently trained or not. Therefore, it is desirable to introduce a method and framework for dynamically allocating appropriate RS resources.

[0033] However, the specifics of the framework have not yet been fully explored. Unless these are properly defined, it may be difficult to achieve highly efficient resource utilization, which may hinder improvements in communication throughput or communication quality.

[0034] Furthermore, in existing specifications (before Rel. 16), it is specified that the configuration of mapping of reference signals (for example, CSI-RS) is controlled based on a predetermined periodicity and a predetermined resource mapping.

[0035] In order to achieve highly efficient resource utilization as described above, it is desirable to reduce the overhead of reference signals (for example, CSI-RS / CSI-RS resources) by configuring more flexible and dynamic reference signal mapping.

[0036] Therefore, the present inventors have studied suitable methods for allocating / using RS resources and have come up with the idea for this embodiment.

[0037] Note that the embodiments of the present disclosure may be applied when AI / ML / prediction is not used, in which case it is possible to change the RS configuration with reduced delay / overhead without RRC reconfiguration.

[0038] In one embodiment of the present disclosure, a UE / BS trains an ML model in a training mode and executes the ML model in a test mode (also referred to as a test mode, etc.), where the accuracy of the ML model trained in the training mode may be validated.

[0039] In the present disclosure, the UE / BS may input channel state information, reference signal measurements, etc. to the ML model and output highly accurate channel state information / measurements / beam selection / position, future channel state information / radio link quality, etc.

[0040] In this disclosure, AI may be interpreted as an object (also referred to as a subject, object, data, function, program, etc.) that has (performs) at least one of the following characteristics: · inferences based on observed or collected information; · making choices based on information observed or collected; · Predictions based on observed or collected information.

[0041] In the present disclosure, the object may be, for example, an apparatus, a device, etc., such as a terminal or a base station. The object may also correspond to a program included in the apparatus.

[0042] In addition, in the present disclosure, an ML model may be interpreted as an object having (implementing) at least one of the following characteristics: - Producing estimates by feeding information, · Predicting estimates by giving information, · Discover features by providing information, · Selecting behavior by providing information.

[0043] In the present disclosure, the term "ML model" may be interpreted as at least one of an AI model, predictive analytics, a predictive analysis model, etc. The ML model may be derived using at least one of regression analysis (e.g., linear regression analysis, multiple regression analysis, logistic regression analysis), a support vector machine, a random forest, a neural network, deep learning, etc. In the present disclosure, the term "model" may be interpreted as at least one of an encoder, a decoder, a tool, etc.

[0044] Based on input information, the ML model outputs at least one piece of information, such as an estimate, a prediction, a selected action, or a classification.

[0045] 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.

[0046] In the following embodiments, to explain an ML model for communication between a UE and a BS, the relevant entities are a UE and a BS, but application of each embodiment of the present disclosure is not limited to this. For example, for communication between other entities (e.g., communication between UEs), 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 all be read as any UE / BS.

[0047] In the present disclosure, "A / B" and "at least one of A and B" may be read interchangeably, and "A / B / C" and "at least one of A, B, and C" may be read interchangeably.

[0048] In the present disclosure, terms such as activate, deactivate, indicate, select, configure, update, and determine may be interchangeable. In the present disclosure, terms such as support, control, controllable, operate, and operable may be interchangeable.

[0049] In the present disclosure, Radio Resource Control (RRC), RRC parameters, RRC messages, higher layer parameters, information elements (IEs), and configurations may be interchangeable. In the present disclosure, Medium Access Control (MAC) control elements (CEs), update commands, and activation / deactivation commands may be interchangeable.

[0050] In the present disclosure, the following terms may be used: panel, UE panel, panel group, beam, beam group, precoder, uplink (UL) transmitting entity, TRP, spatial relationship information (SRI), spatial relationship, SRS Resource Indicator (SRI), SRS resource, control resource set (CORESET), Physical Downlink Shared Channel (PDSCH), codeword, base station, reference signal, predetermined antenna port (e.g., Demodulation Reference Signal (DMRS) port), predetermined antenna port group (e.g., DMRS port group), predetermined group (e.g., Code Division Multiplexing (CDM) group, predetermined reference signal group, CORESET group), predetermined resource (e.g., predetermined reference signal resource), predetermined resource set (e.g., predetermined reference signal resource set), CORESET pool, PUCCH group (PUCCH resource group), spatial relationship group, downlink Transmission Configuration Indication state (TCI state) (DL Terms such as uplink TCI state, uplink TCI state (UL TCI state), unified TCI state, common TCI state, quasi-co-location (QCL), and QCL assumption may be read interchangeably.

[0051] In this disclosure, the terms index, ID, indicator, and resource ID may be interchangeable. In this disclosure, the terms sequence, list, set, group, group, cluster, and subset may be interchangeable.

[0052] In the present disclosure, beam reports may be interchangeably referred to as beam measurement reports, CSI reports, CSI measurement reports, predicted beam reports, predicted CSI reports, etc.

[0053] In the present disclosure, CSI-RS may be interchangeably read as at least one of Non-Zero Power (NZP) CSI-RS, Zero Power (ZP) CSI-RS, and CSI Interference Measurement (CSI-IM).

[0054] In this disclosure, the measured / reported RS may refer to the RS measured / reported for a beam report.

[0055] In the present disclosure, the terms timing, time, duration, slot, subslot, symbol, subframe, etc. may be interpreted as interchangeable.

[0056] In the present disclosure, the terms direction, axis, dimension, polarization, polarization component, etc. may be interpreted interchangeably.

[0057] In the present disclosure, estimation, prediction, and inference may be interchangeable. In the present disclosure, estimate, predict, and infer may be interchangeable.

[0058] In the present disclosure, the RS may be, for example, a CSI-RS, an SS / PBCH block (SS block (SSB)), etc. Furthermore, the RS index may be a CSI-RS resource indicator (CSI-RS resource indicator (CRI)), an SS / PBCH block resource indicator (SSBRI), etc.

[0059] In the present disclosure, CSI feedback, CSI feedback information, CSI report, CSI report, CSI transmission, CSI information, CSI, etc. may be interpreted as interchangeable.

[0060] In addition, in the present disclosure, a subband may be interchangeably read as a physical resource block (PRB), a subcarrier, an arbitrary frequency resource unit, and the like.

[0061] (Wireless communication method) Although a channel state information reference signal (CSI-RS) is taken as an example of a (specific) reference signal described in each embodiment of the present disclosure, the present disclosure is not limited to this and may be applied to any reference signal.

[0062] In the present disclosure, the terms "assigning," "mapping," "transmitting," and "receiving" a reference signal may be read interchangeably.

[0063] First Embodiment In the first embodiment, the time domain configuration of CSI-RS resources will be described.

[0064] The periodicity of CSI-RS resources may be set / applied to a value greater than the maximum periodicity in existing systems (e.g., Rel. 16 and earlier). For example, the periodicity of CSI-RS resources may be set / applied to a predetermined periodicity value greater than 640 slots. The predetermined periodicity value may be, for example, 1280 slots, 2560 slots, etc.

[0065] In this way, by supporting the setting / application of a larger value for the periodicity of CSI-RS resources than in existing systems, it is possible to reduce the overhead of CSI-RS resources.

[0066] Furthermore, a new offset value (e.g., time offset value) of the CSI-RS resource may be configured for a given periodicity value. For example, a setting of 0 to (X-1) slots may be supported as the offset corresponding to a periodicity of X slots.

[0067] The predetermined periodicity value may be configured with a granularity / unit other than a slot. For example, configuration of the periodicity (e.g., the predetermined periodicity value) of the CSI-RS resource may be supported using a unit with a granularity greater than a slot (e.g., subframe / frame / ms / s / minis / hours). In this case, the periodicity offset value may be configured with the granularity of the slot or with a new granularity (e.g., a unit with a granularity greater than a slot).

[0068] For example, the offset corresponding to the subframe / frame / ms / s / minis / hours of periodicity X may be set to 0 to (X-1) slots. Alternatively, the offset corresponding to the subframe / frame / ms / s / minis / hours of periodicity X may be set to 0 to (X-1) subframes / frames / ms / s / minis / hours. The granularity / unit of the periodicity and the granularity / unit of the offset may be set / applied in common.

[0069] By supporting a granularity greater than slot for the CSI-RS periodicity / offset values, it is possible to suppress the increase in overhead of higher layer signaling even when the periodicity / offset values ​​become large.

[0070] <Second embodiment> In the second embodiment, the configuration of the frequency domain of the CSI-RS resource will be described. Note that the configuration shown in the second embodiment may be applied in appropriate combination with the content shown in the first embodiment.

[0071] <<Aspect 2-1>> The frequency domain density of CSI-RS resources (e.g., frequency domain density) may be set / applied to a value different from the values ​​(e.g., 3, 1, 0.5) of the existing system. The newly set / applied frequency domain density value may be applied to each row of the CSI-RS resource positions shown in FIG. 3, or may be selectively applied to some rows.

[0072] Alternatively, the newly set / applied frequency domain density value may be applied to a new row different from the rows (e.g., row #1 to row #18) indicating the CSI-RS resource locations shown in Fig. 3. Note that in the present disclosure, row may be interpreted as a configuration of CSI-RS locations (e.g., CSI-RS locations within a slot) or CSI-RS location candidates.

[0073] As a new frequency domain density (for example, ρ_new) different from the frequency domain densities (for example, 3, 1, 0.5) of the existing system, at least one of Option 2-1-1 to Option 2-1-2 below may be applied.

[0074] [Option 2-1-1] The new frequency-domain density (e.g., ρ_new) may be defined as 1 / N, where N may be a predetermined integer value. Alternatively, N may be a multiple of 2, 4, 8, 12, etc. For example, the new frequency-domain density value 1 / N may be a value less than 0.5.

[0075] If the new frequency domain density (e.g., ρ_new) is 1 / N, this may mean that the CSI-RS resource mapping pattern (e.g., row) is repeated only once every N(=1 / ρ_new) resource blocks (e.g., RBs).

[0076] Figure 6A shows an example of a CSI-RS resource mapping pattern (or parameters) corresponding to row #2, and Figure 6B shows an example of a CSI-RS location corresponding to row #2. Here, the number of ports is 1, the density is 1 / 4 (N=4, ρ_new=1 / 4), and there is no CDM. That is, the CSI-RS resource mapping pattern (here, row #2) is repeated once every four resource blocks (e.g., RBs).

[0077] N related to the frequency domain density may be notified to the UE by upper layer signaling.

[0078] [Option 2-1-2] The new frequency domain density (e.g., ρ_new) may be defined as M / N. M is a predetermined integer value, and N may be a predetermined integer value or a multiple of 2 / 4 / 8 / 12…. M and N may be set separately, and may be defined as M < N (or, M > N). For example, the value M / N of the new frequency domain density may be a value less than 0.5 or a value greater than 0.5. Also, 1 / ρ may be an integer value or may not be an integer value.

[0079] M / N related to the frequency domain density may be notified to the UE by upper layer signaling. Note that the values of M and N may be notified to the UE respectively. In this case, by controlling the values of M and N, it is possible to flexibly set the frequency domain density.

[0080] When the value of the new frequency domain density (e.g., ρ_new) is M / N, it may mean that the CSI-RS resource mapping pattern is repeated with M RBs for every N (=1 / ρ_new) resource blocks (e.g., RBs). The M RBs may be consecutive RBs or non-consecutive RBs.

[0081] FIG. 6C shows an example of the CSI-RS position corresponding to row #2. Here, the case of 1 port number, density of 2 / 5 (M = 2, N = 5, ρ_new = 2 / 5), and no CDM is shown. That is, the CSI-RS resource mapping pattern is repeated only with 2 RBs for every 5 resource blocks (e.g., RBs). Here, the case where the 2 RBs repeated for every 5 RBs are non-consecutive is shown, but it is not limited to this.

[0082] When the new frequency domain density shown in Option 2-1-1 / Option 2-1-2 is supported, the RB positions occupied by CSI-RS (e.g., occupied RB position(s)) may be defined in the specifications or may be instructed to the UE by the network. The RB positions occupied by CSI-RS may be interpreted as the RB positions where the CSI-RS is located, the RB positions where the CSI-RS is mapped, or the RB positions where the CSI-RS is allocated.

[0083] 《Alt2-1-1》 A starting RB position within the N RBs may be defined / indicated. For example, an offset of the starting RB position relative to the lowest (or highest) RB index among the N RBs may be defined / indicated.

[0084] In option 2-1-1, the indicated starting RB position may refer to the RB position occupied by the CSI-RS.

[0085] In option 2-1-2, the M RBs occupied by CSI-RS may be frequency-allocated with a fixed offset (e.g., Y RB offset) between the RBs occupied by CSI-RS. In this case, Y may be set by higher layer signaling or may be defined in a specification. Y defined in a specification (e.g., Y=0) may mean that consecutive RBs among N RBs are allocated to CSI-RS.

[0086] If the starting RB position is not indicated / set, a default starting position may be applied, which may be, for example, the lowest (or highest) RB index among the N RBs.

[0087] The starting RB position among the N RBs may be included in a table used for CSI-RS resource mapping positions or may be included in higher layer parameters related to CSI-RS resource mapping.

[0088] 《Alt2-1-2》 To indicate the RBs occupied by CSI-RS for every N RBs, a bitmap indicating the RB position (e.g., RB position) for the new frequency domain density value may be set (see FIG. 7).

[0089] For example, in option 2-1-1, only one bit among the multiple bits indicating the RBs occupied by the CSI-RS may be set to 1. In option 2-1-2, the total number of bits among the multiple bits set to 1 may be set to be equal to M.

[0090] For example, "0001" may mean that the CSI-RS pattern is mapped to the first (or last) RB of every four RBs, and "00010101" may mean that the CSI-RS pattern is mapped to the {i, i+2, i+4}th RB or {i+3, i+5, i+7}th RB of every eight RBs.

[0091] If the starting RB position is not indicated / configured, a default starting position may be applied, which may be, for example, a configuration in which M consecutive RBs having the lowest (or highest) RB index among N RBs are occupied by CSI-RS.

[0092] The bitmap may be included in a table used for CSI-RS resource mapping locations, or may be included in higher layer parameters related to CSI-RS resource mapping.

[0093] <<Aspect 2-2>> If the frequency domain density of CSI-RS resources (e.g., frequency domain density) is less than 1, mapping / allocation of CSI-RS resources (e.g., different ports / CDM groups) to multiple RBs (or different RBs) may be supported.

[0094] For example, when the density in the frequency domain is less than 1, the configuration of CSI-RS positions within a slot (e.g., CSI-RS locations within a slot) may be applied across multiple RBs (or different RBs). The configuration of CSI-RS positions within a slot may be, for example, at least one of row #1 to row #18 (or a newly defined / configured row) included in the table shown in FIG. 3.

[0095] FIG. 8A shows an example of a CSI-RS resource mapping pattern (or parameters) corresponding to row #14, and FIG. 8B shows an example of a CSI-RS position in an existing system corresponding to row #14. Here, the case is shown where the number of ports is 24, the density is 0.5, and cdm4-FD2-TD2. In other words, the CSI-RS resource mapping pattern (or row 14) is repeated once every two RBs. FIG. 8B also shows a case where CSI-RS is mapped to one of the two RBs and not mapped to the other.

[0096] In Fig. 8B, in the frequency domain and time domain of 1 PRB x 1 slot, component resources of 2 subcarriers x 2 symbols are multiplexed three times (FDM) in the frequency domain and multiplexed two times (TDM) in the time domain to map 3 x 2 component resources. Furthermore, the CSI-RS in each component resource is multiplied by an FD-OCC with a length of 2 subcarriers and a TD-OCC with a length of 2 symbols, thereby multiplexing (CDM) four CSI-RS. The CSI-RS includes six CDM groups, and each CDM group includes four ports.

[0097] 8C shows an example of a CSI-RS position corresponding to row #14 when the second aspect is applied. Here, the case is shown where the number of ports is 24, the density is 0.5, and cdm4-FD2-TD2. That is, the CSI-RS resource mapping pattern is repeated once every two resource blocks (e.g., RBs). Also, here, the CSI-RS is mapped to both of the two RBs (or across the two RBs). For example, different ports / CDM groups are mapped to the two RBs.

[0098] In Figure 8C, in the frequency domain and time domain of 2 PRBs x 1 slot, component resources of 2 subcarriers x 2 symbols are multiplexed three-by-three (FDM) in the frequency domain and multiplexed two-by-two (TDM) in the time domain to map 3 x 2 component resources. Furthermore, the CSI-RS in each component resource is multiplied by an FD-OCC with a length of 2 subcarriers and a TD-OCC with a length of 2 symbols, thereby multiplexing (CDM) four CSI-RS. The CSI-RS includes six CDM groups, and each CDM group includes four ports. Here, a case is shown in which CDM groups 0, 1, 3, and 4 are mapped to the first RB, and CDM groups 2 and 5 are mapped to the second RB.

[0099] In this way, by mapping different ports / different CDM groups corresponding to CSI-RS (e.g., CSI-RS positions corresponding to a specific row) to multiple RBs, it is possible to improve the flexibility of CSI-RS mapping and obtain frequency domain diversity. It is also possible to reduce the frequency domain density in one slot. Furthermore, by applying this in combination with aspect 2-1, it is possible to effectively reduce the frequency domain density.

[0100] When the frequency domain density is less than 1, in the case where different ports / different CDM groups are mapped to multiple RBs, the value range of k / ki in the CSI-RS location configuration (e.g., CSI-RS resource mapping table) may be extended / changed. In this case, the bitmap length (or size) set / signaled by a higher layer parameter related to frequency domain allocation (e.g., FrequencyDomainAllocation) may be extended. The higher layer parameter (e.g., frequencyDomainAllocation) may indicate frequency domain resource occupation in multiple RBs.

[0101] The bitmap length set / signaled by the higher layer parameters may be changeable (or variable) based on a predetermined condition (e.g., the frequency domain density of CSI-RS). For example, if the frequency domain density is 0.5, the bitmap length (or size) may be doubled. Also, the value range of k / ki may be expanded (e.g., [0, 22] for FD2, [0, 23] for fd-CDM2).

[0102] Furthermore, the bitmap length extension may be supported only for a specific CSI-RS location configuration (e.g., a specific row), for all rows, or for a new row. The specific row may be, for example, any row other than row #1, row #2, and row #4. The new row may be a row introduced for the purpose of mapping different CDM groups / ports to different RBs.

[0103] When the bitmap lengths of rows other than row #1, row #2, and row #4 are extended, the following relationship may be defined for each row of the table related to CSI-RS positions. Row 1 (row#1):[b3…b0],k i-1 =f(i) Row 2 (row#2):[b11...b0],k i-1 =f(i) Row 4 (row#4):[b2...b0],k i-1 =4f(i) Other rows (cases other than row#1 / #2 / #4): [b11……b0], k i-1 =2f(i) f(i) denotes the number of the i-th bit in the bitmap that is set to 1, and is repeated every two consecutive RBs (eg, when the density in the frequency domain is 0.5).

[0104] Furthermore, higher layer parameters for RBs indicated for a frequency domain density of 0.5 (eg, {evenPRBs, oddPRBs}) may indicate the RBs to which a particular CDM group (eg, CDM group 0) is mapped.

[0105] 9A shows an example of a CSI-RS resource mapping pattern corresponding to row #14. The network (e.g., base station) may indicate to the UE a bitmap with an expanded size as an upper layer parameter (e.g., frequencyDomainAllocation) related to the frequency domain allocation of CSI-RS. Here, the case where "100000001010" is indicated as the bitmap corresponding to row #14 is shown.

[0106] The UE selects a row (here, row #14) corresponding to the CSI-RS based on higher layer parameters including a bitmap notified by the base station, and then determines the frequency domain location of the CSI-RS. The UE may determine the row based on the port / density / CDM type notified by the higher layer parameters, or information specifying the row may be notified to the UE by the higher layer parameters.

[0107] If the frequency domain density is 0.5 for row #14, the UE i-1= 2f(i) and the bitmap (100000001010), it is determined that the frequency domain locations of the CSI-RS (each component resource) are k0 = 2, k1 = 6, and k2 = 22 (see FIG. 9B).

[0108] 9B shows a case where CSI-RS (different CDM groups / ports) corresponding to row #14 are mapped to two RBs. The frequency domain position of the CSI-RS corresponding to CDM groups 0 and 3 is determined based on k0 (= 2), the frequency domain position of the CSI-RS corresponding to CDM groups 1 and 4 is determined based on k1 (= 6), and the frequency domain position of the CSI-RS corresponding to CDM groups 2 and 5 is determined based on k2 (= 22). Note that the reference point for ki in the frequency direction may be one of the multiple (here, two) RBs (for example, subcarrier 0 of the RB with the smaller index).

[0109] Although Figure 9A illustrates the use of rows included in a table related to CSI-RS locations in an existing system, this is not limiting. When different CDM groups / ports are mapped to different RBs, new CSI-RS location configurations (e.g., new rows) may be supported (see Figure 10A).

[0110] 10A shows an example of a CSI-RS resource mapping pattern corresponding to a new row #x, where the number of ports is 48, the density is 0.5, and the frequency domains are represented by k0, k1, k2, k3, k4, and k5.

[0111] The network (e.g., a base station) may indicate to the UE the bitmap with the expanded size as an upper layer parameter (e.g., frequencyDomainAllocation) related to the frequency domain allocation of CSI-RS. Here, a case is shown in which "101010101010" is indicated as the bitmap corresponding to row #x.

[0112] The UE selects a row (here, row #x) corresponding to the CSI-RS based on higher layer parameters including a bitmap notified by the base station, and then determines the frequency domain location of the CSI-RS. The UE may determine the row based on the port / density / CDM type notified by the higher layer parameters, or information specifying the row may be notified to the UE by the higher layer parameters.

[0113] For row#x, UE is [b11……b0],k i-1 = 2f(i) and the bitmap (101010101010), it is determined that the frequency domain positions of the CSI-RS (each component resource) are k0 = 2, k1 = 6, k2 = 10, k3 = 14, k4 = 18, and k5 = 22 (see Figure 10B).

[0114] Figure 10B shows an example of CSI-RS locations corresponding to row #x. CSI-RS resources are mapped to both of two RBs (or across two RBs). For example, different ports / CDM groups are mapped to each of the two RBs. This example shows a case where CDM groups 0, 1, 2, 6, 7, and 8 are mapped to the first RB, and CDM groups 3, 4, 5, 9, 10, and 11 are mapped to the second RB.

[0115] The frequency domain position of the CSI-RS corresponding to CDM groups 0 and 6 is determined based on k0 (= 2). Similarly, the frequency domain position of the CSI-RS corresponding to CDM groups 1 and 7 is determined based on k1 (= 6), the frequency domain position of the CSI-RS corresponding to CDM groups 2 and 8 is determined based on k2 (= 10), the frequency domain position of the CSI-RS corresponding to CDM groups 3 and 9 is determined based on k3 (= 14), the frequency domain position of the CSI-RS corresponding to CDM groups 4 and 10 is determined based on k4 (= 18), and the frequency domain position of the CSI-RS corresponding to CDM groups 5 and 11 is determined based on k5 (= 22). Note that the reference point for ki in the frequency direction may be one of multiple (here, two) RBs (e.g., subcarrier 0 of an RB with a smaller index).

[0116] 9A and 10A show the case where the bitmap length is extended, but it is also possible to have a configuration where the bitmap length is not extended and an offset is added to the k bar (e.g., ki) defined / set in the CSI-RS position configuration (e.g., row) (or the range of the k bar is extended).

[0117] In this case, a new row may be introduced into the table related to CSI-RS locations, and the range of k / k in the new row may be defined differently from that of the existing rows. For example, 0≦k≦12 / ρ−1, 0≦k≦11 may be allowed. The indicated resource mapping allocation (k, l) may be repeated at 1 / ρ RBs. A higher layer parameter related to frequency domain allocation (e.g., frequencyDomainAllocation) may indicate the location of frequency domain resource allocation in one RB.

[0118] 11A shows an example of a CSI-RS resource mapping pattern corresponding to new row #x. Here, the number of ports is 24, the density is 0.5, and the pattern is cdm4-FD2-TD2. The frequency domain is represented by k0, k1+12, and k2. That is, an offset (here, +12) is added in the frequency direction to the CDM group corresponding to k1 (here, CDM groups 1 and 4).

[0119] The network (e.g., a base station) may indicate to the UE a bitmap whose size is not expanded as an upper layer parameter (e.g., frequencyDomainAllocation) related to frequency domain allocation of CSI-RS. Here, a case where "101010" is indicated as the bitmap corresponding to row #x is shown.

[0120] The UE selects a row (here, row #x) corresponding to the CSI-RS based on higher layer parameters including a bitmap notified by the base station, and then determines the frequency domain location of the CSI-RS. The UE may determine the row based on the port / density / CDM type notified by the higher layer parameters, or information specifying the row may be notified to the UE by the higher layer parameters.

[0121] For row#x, UE is [b5……b0],k i-1 = 2f(i) and the bitmap (101010), it is determined that k0 = 2, k1 = 6, and k2 = 10, and the frequency domain position of the CSI-RS (each component resource) is determined (see FIG. 11B).

[0122] Figure 11B shows an example of a CSI-RS location corresponding to row #x. CSI-RS resources are mapped to both of two RBs (or across two RBs). For example, different ports / CDM groups are mapped to the two RBs. Here, CDM groups 0, 2, 3, and 5 are mapped to the first RB, and CDM groups 1 and 4 are mapped to the second RB.

[0123] The frequency domain location of the CSI-RS corresponding to CDM groups 0 and 3 is determined based on k0 (= 2). The frequency domain location of the CSI-RS corresponding to CDM groups 1 and 4 is determined based on k1 (= 6) + 12. The frequency domain location of the CSI-RS corresponding to CDM groups 2 and 5 is determined based on k2 (= 10).

[0124] The reference point of ki in the frequency direction may be one of multiple (here, two) RBs (for example, subcarrier 0 of the RB with the smaller index). Alternatively, the reference point of ki to which a predetermined offset (here, 12) is added may be the other RB (for example, subcarrier 0 of the RB with the larger index).

[0125] 12 and 13 show other examples of mapping different CDM groups to different RBs by extending k-bar (or adding an offset to ki).

[0126] 12 shows an example of a CSI-RS resource mapping pattern (or parameters) corresponding to row #x and row #y. Here, the number of ports is 48, the density is 0.5, and cdm4-FD2-TD2 is shown. Also, the frequency domain is shown as k0, k1, k2, k0+12, k1+12, and k2+12. Here, the values ​​of (k bar, l bar) corresponding to each CDM group are defined differently (or in reverse order) in row #x and row #y.

[0127] The network (e.g., a base station) may indicate to the UE a bitmap whose size is not expanded as an upper layer parameter (e.g., frequencyDomainAllocation) related to frequency domain allocation of CSI-RS. Here, the case where "101010" is indicated as the bitmap corresponding to row#x / row#y is shown.

[0128] The UE selects a row (here, row #x or row #y) corresponding to the CSI-RS based on higher layer parameters including a bitmap notified by the base station, and then determines the frequency domain location of the CSI-RS. The UE may determine the row based on the port / density / CDM type notified by the higher layer parameters, or information specifying the row may be notified to the UE by the higher layer parameters.

[0129] For row#x / row#y, UE is [b5……b0],k i-1 = 2f(i) and the bitmap (101010), it is determined that k0 = 2, k1 = 6, and k2 = 10, and the frequency domain position of the CSI-RS (each component resource) is determined (see FIG. 13).

[0130] Figure 13 shows an example of CSI-RS locations corresponding to row #x and row #y, respectively. CSI-RS resources are mapped to both of the two RBs (or across the two RBs). For example, different ports / CDM groups are mapped to the two RBs.

[0131] Here, for row #x, a case is shown in which CDM groups 0, 1, 2, 6, 7, and 8 are mapped to the first RB, and CDM groups 3, 4, 5, 9, 10, and 11 are mapped to the second RB. The frequency domain location of the CSI-RS corresponding to CDM groups 0 and 6 is determined based on k0 (= 2), the frequency domain location of the CSI-RS corresponding to CDM groups 1 and 7 is determined based on k1 (= 6), and the frequency domain location of the CSI-RS corresponding to CDM groups 2 and 8 is determined based on k2 (= 10). The frequency domain location of the CSI-RS corresponding to CDM groups 3 and 9 is determined based on k0 (= 2) + 12, the frequency domain location of the CSI-RS corresponding to CDM groups 4 and 10 is determined based on k1 (= 6) + 12, and the frequency domain location of the CSI-RS corresponding to CDM groups 5 and 11 is determined based on k2 (= 10) + 12.

[0132] On the other hand, for row #y, the example shows a case where CDM groups 0, 1, 2, 3, 4, and 5 are mapped to the first RB, and CDM groups 6, 7, 8, 9, 10, and 11 are mapped to the second RB. The frequency domain location of the CSI-RS corresponding to CDM groups 0 and 3 is determined based on k0 (= 2), the frequency domain location of the CSI-RS corresponding to CDM groups 1 and 4 is determined based on k1 (= 6), and the frequency domain location of the CSI-RS corresponding to CDM groups 2 and 5 is determined based on k2 (= 10). The frequency domain location of the CSI-RS corresponding to CDM groups 6 and 9 is determined based on k0 (= 2) + 12, the frequency domain location of the CSI-RS corresponding to CDM groups 7 and 10 is determined based on k1 (= 6) + 12, and the frequency domain location of the CSI-RS corresponding to CDM groups 8 and 11 is determined based on k2 (= 10) + 12.

[0133] In this way, by adding an offset to the ki corresponding to each CDM group, when the density of the CSI-RS in the frequency domain is less than 1, it becomes possible to flexibly control the RBs to which the CDM groups are mapped.

[0134] In the above description, the case where the frequency domain density is 0.5 is shown as a case where the frequency domain density is smaller than 1, but the applicable frequency domain density is not limited to 0.5. Aspect 2-2 may be applied to frequency domain densities other than 0.5 (for example, Aspect 2-1 and Aspect 2-2 may be applied in combination).

[0135] 14A shows an example of a CSI-RS resource mapping pattern corresponding to row # 14. Here, a case where 1 / 4 (N=4) is supported as the frequency domain density is shown.

[0136] The network (e.g., a base station) may indicate the expanded size bitmap to the UE as an upper layer parameter (e.g., frequencyDomainAllocation) related to the frequency domain allocation of CSI-RS.

[0137] The bitmap length set / signaled by a higher layer parameter may be changeable (or variable) based on a predetermined condition (e.g., frequency domain density of CSI-RS). For example, when density ρ_new=1 / N or ρ_new=M / N, the bitmap length (or size) signaled by a higher layer parameter (e.g., frequencyDomainAllocation) may be extended by a factor of N. Also, the value range of k / ki may be extended (e.g., [0, N×12−2]).

[0138] Furthermore, the bitmap length extension may be supported only for a specific CSI-RS location configuration (e.g., a specific row), may be supported only for all rows, or may be supported for a new row. The specific row may be, for example, any row other than row #1, row #2, and row #4.

[0139] If the bitmap length is extended, the following relationship may be defined for a given row of the table for CSI-RS location: [b6*N-1,b6*N-2……b0],k i-1 =2f(i) f(i) denotes the number of the i-th bit in the bitmap that is set to 1, and is repeated every N consecutive RBs.

[0140] The occupied RB positions (e.g., occupied RB position(s)) indicated / defined in aspect 2-1 may indicate the RB positions of a specific CDM group index (e.g., CDM group index 0). The occupied RB positions may be indicated by higher layer signaling or may be defined by specification for each row.

[0141] Here, the case where "000000,100000,001000,000010" is designated as the bitmap corresponding to row#x is shown.

[0142] The UE selects a row (here, row #x) corresponding to the CSI-RS based on higher layer parameters including a bitmap notified by the base station, and then determines the frequency domain location of the CSI-RS. The UE may determine the row based on the port / density / CDM type notified by the higher layer parameters, or information specifying the row may be notified to the UE by the higher layer parameters.

[0143] For row #14, UE sets [b6*N-1,b6*N-2……b0],k i-1 = 2f(i) and the bitmap (000000, 100000, 001000, 000010), it is determined that the frequency domain position of the CSI-RS (each component resource) is k0 = 2, k1 = 18, k2 = 32 (see FIG. 14B).

[0144] Figure 14B shows an example of a CSI-RS location corresponding to row #14. CSI-RS resources can be mapped across four RBs (here, they are mapped to three RBs). For example, different ports / CDM groups can be mapped to each of the four RBs. Here, a case is shown in which CDM groups 0 and 3 are mapped to the first RB, CDM groups 1 and 4 are mapped to the second RB, CDM groups 2 and 5 are mapped to the third RB, and no CSI group is mapped to the fourth RB.

[0145] The frequency domain position of the CSI-RS corresponding to CDM groups 0 and 3 is determined based on k0 (= 2). Similarly, the frequency domain position of the CSI-RS corresponding to CDM groups 1 and 4 is determined based on k1 (= 18), and the frequency domain position of the CSI-RS corresponding to CDM groups 2 and 5 is determined based on k2 (= 32). Note that the reference point for ki in the frequency direction may be a specific RB (for example, subcarrier 0 of the RB with the smallest index) among multiple (here, four) RBs.

[0146] FIG. 14A shows a case where the bitmap length is extended, but it is also possible to use a configuration where the bitmap length is not extended, but an offset is added to the k bar (e.g., ki) defined / set in the CSI-RS position configuration (e.g., row) (or the range of the k bar is extended) (see FIG. 15A).

[0147] In this case, a new row may be introduced into the table related to CSI-RS locations, and the range of k / k in the new row may be defined differently from that of the existing rows. For example, 0≦k≦12 / ρ−1, 0≦k≦11 may be allowed. The indicated resource mapping allocation (k, l) may be repeated at 1 / ρ RBs. A higher layer parameter related to frequency domain allocation (e.g., frequencyDomainAllocation) may indicate the location of frequency domain resource allocation in one RB.

[0148] 15A shows an example of a CSI-RS resource mapping pattern corresponding to new row #x. Here, the number of ports is 24, the density is 1 / 4, and cdm4-FD2-TD2 is shown. The frequency domain is represented by k0, k1+12, and k2+24. That is, offsets are added in the frequency direction to the CDM group corresponding to k1 (here, CDM groups 1 and 4) and the CDM group corresponding to k2 (here, CDM groups 2 and 5).

[0149] The offset may be a multiple of a predetermined value (e.g., 12). The value of the offset may be determined based on predetermined parameters. For example, the offset may be determined based on at least one of a CDM type, a number of ports, a frequency domain density, and a parameter configured by RRC.

[0150] The network (e.g., base station) may instruct the UE to use a bitmap whose size is not expanded as a higher layer parameter (e.g., frequencyDomainAllocation) related to the frequency domain allocation of CSI-RS. For example, a table of CSI-RS locations within a slot including frequency offsets exceeding 12 as described above may be added according to a predetermined rule, and the network may determine whether to use the existing table or the added table based on the higher layer parameter. Alternatively, a new row may be added to an existing column, and the row to be referenced may be determined based on the higher layer parameter. Here, the case where "101010" is instructed as the bitmap corresponding to row#x is shown.

[0151] The UE selects a row (here, row #x) corresponding to the CSI-RS based on higher layer parameters including a bitmap notified by the base station, and then determines the frequency domain location of the CSI-RS. The UE may determine the row based on the port / density / CDM type notified by the higher layer parameters, or information specifying the row may be notified to the UE by the higher layer parameters.

[0152] For row#x, UE is [b5……b0],k i-1 = 2f(i) and the bitmap (101010), it is determined that k0 = 2, k1 = 6, and k2 = 10, and the frequency domain position of the CSI-RS (each component resource) is determined (see FIG. 15B).

[0153] Figure 15B shows an example of a CSI-RS location corresponding to row #x. CSI-RS resources can be mapped across four RBs (here, they are mapped to three RBs). For example, different ports / CDM groups can be mapped to each of the four RBs. Here, CDM groups 0 and 3 are mapped to the first RB, CDM groups 1 and 4 are mapped to the second RB, CDM groups 2 and 5 are mapped to the third RB, and no CSI group is mapped to the fourth RB.

[0154] The frequency domain location of the CSI-RS corresponding to CDM groups 0 and 3 is determined based on k0 (= 2). The frequency domain location of the CSI-RS corresponding to CDM groups 1 and 4 is determined based on k1 (= 6) + 12. The frequency domain location of the CSI-RS corresponding to CDM groups 2 and 5 is determined based on k2 (= 10) + 24.

[0155] Note that the reference point of ki in the frequency direction may be one of the multiple (here, four) RBs (for example, subcarrier 0 of the RB with the smallest index).

[0156] In the above description, the offset (e.g., 12 / 24) is based on the subcarrier, but this is not limiting. For example, in the present disclosure, the unit of the offset may be RB. For example, the offset added to k1 may be 1 (RB), and the offset added to k2 may be 2 (RB).

[0157] In this way, by applying a combination of example 2-1 and example 2-2, it is possible to flexibly control the mapping of CSI-RS resources in the frequency domain and reduce the overhead of CSI-RS resources mapped to the frequency domain.

[0158] <<Aspect 2-3>> When multiple (eg, two) starting symbols are configured within one slot, setting / application of different frequency domain resource allocations to different starting symbols may be supported.

[0159] Note that example 2-3 may be applied to a CSI-RS position configuration in which multiple start symbols are set within one slot (for example, rows #11, #13, #14, #17, or a new row in the table related to CSI-RS positions).

[0160] When multiple start symbols are configured within one slot, it may be supported that the frequency domain resource allocation of CSI-RS resources is configured separately (eg, differently) for each start symbol.

[0161] 16A shows a case where multiple start symbols are configured in one slot, and the frequency domain resource allocation of CSI-RS is configured in common for the multiple start symbols (e.g., l0, l1). In FIG. 16A, the frequency domain resource allocation of CDM groups 0-2 mapped to the first start symbol and the frequency domain resource allocation of CDM groups 3-5 mapped to the second start symbol are configured to be the same. Specifically, CDM group 0 mapped to the first start symbol and CDM group 3 mapped to the second start symbol are assigned to common frequency domain resources.

[0162] On the other hand, Figure 16B shows a case where multiple start symbols are configured in one slot, and the frequency domain resource allocation of CSI-RS is configured separately (e.g., differently) for each start symbol. For example, in Figure 16B, the frequency domain resource allocation of CDM groups 0-2 mapped to the first start symbol and the frequency domain resource allocation of CDM groups 3-5 mapped to the second start symbol are configured separately. Specifically, CDM group 0 mapped to the first start symbol and CDM group 3 mapped to the second start symbol are assigned to different frequency domain resources.

[0163] In this way, by performing frequency domain resource allocation separately for different start symbols, it becomes possible to flexibly control subcarrier allocation for different ports. Also, in addition to the number of ports supported by existing systems (e.g., 1 / 2 / 4 / 8 / 12 / 16 / 24 / 32 ports), it becomes possible to support other numbers of ports / port numbers (e.g., 20 ports / 28 ports). This makes it possible to set different numbers of CDM groups corresponding to the first start symbol and the second start symbol.

[0164] For multiple (e.g., two) starting symbols in one slot, bitmaps corresponding to multiple (e.g., two) frequency domains may be set / indicated / applied. Bitmaps corresponding to multiple frequency domains may be set / indicated / applied by higher layer parameters (see FIG. 17).

[0165] 17 illustrates an example of higher layer parameters related to CSI-RS resource mapping (e.g., CSI-RS-ResourceMapping). A network (e.g., a base station) may notify a UE of two frequency domain bitmaps (e.g., frequencyDomainAllocation and frequencyDomainAllocation2) using the higher layer parameters related to CSI-RS resource mapping.

[0166] The UE may apply the notified multiple (e.g., two) frequency domain bitmaps to different start symbols. Note that, although the size (or bitmap length) of the second bitmap is set to 6 in FIG. 17, other values ​​may be supported.

[0167] The second bitmap (e.g., frequencyDomainAllocation2) may be an additional bitmap added to the first bitmap (e.g., frequencyDomainAllocation). The second bitmap (e.g., frequencyDomainAllocation2) may be present only when a specific CSI-RS location configuration (e.g., row) is configured / indicated. The specific row may be a row (e.g., row #13 / #14 / #16 / #17) in which multiple start symbols are configured within one slot. If the second bitmap is not included when a specific row is configured, the UE may apply the same rule as the CSI-RS resource mapping pattern of the existing system (Rel. 15 / 16).

[0168] 18A shows an example of a CSI-RS resource mapping pattern corresponding to row #14. Here, the cases are shown where the number of ports is 24, 20, and 28, and the densities are 1, 0.5, and cdm4-FD2-TD2. Also shown is a case where the frequency domains corresponding to the first start symbol (e.g., l0) and the second start symbol (e.g., l1) are indicated by k0, k1, and k2. The number of ports to be configured may be specified by higher layer signaling.

[0169] The network (e.g., a base station) may notify the UE of a first frequency domain resource allocation (e.g., frequencyDomainAllocation / first bitmap) and a second frequency domain resource allocation (e.g., frequencyDomainAllocation2 / second bitmap) as higher layer parameters related to frequency domain allocation of CSI-RS.

[0170] The UE selects a row (here, row #14) corresponding to the CSI-RS based on higher layer parameters including a bitmap notified by the base station, and then determines the frequency domain location of the CSI-RS. The UE may determine the row based on the port / density / CDM type notified by the higher layer parameters, or information specifying the row may be notified to the UE by the higher layer parameters.

[0171] UE is [b5……b0],k i-1 = 2f(i), the first bitmap, and the second bitmap, the frequency domain position (k0, k1, k2) of the CSI-RS (each component resource) at each start symbol is determined (see Figures 18B-18D). Figure 18B corresponds to CSI-RS resources with 24 ports, Figure 18C corresponds to CSI-RS resources with 20 ports, and Figure 18D corresponds to CSI-RS resources with 28 ports.

[0172] 18B shows a case where the number of ports is 24 (6 CDM groups), and "101010" is signaled as the first bitmap, and "010101" is signaled as the second bitmap. In this case, the UE determines that the frequency domain position of the CSI-RS (each component resource) in the first start symbol is k0=2, k1=6, k2=10. On the other hand, the UE determines that the frequency domain position of the CSI-RS (each component resource) in the second start symbol is k0=0, k1=4, k2=8.

[0173] 18C shows a case where the number of ports is 20 (5 CDM groups), and "101010" is signaled as the first bitmap, and "000101" is signaled as the second bitmap. In this case, the UE determines that the frequency domain position of the CSI-RS (each component resource) in the first start symbol is k0=2, k1=6, k2=10. On the other hand, the UE determines that the frequency domain position of the CSI-RS (each component resource) in the second start symbol is k0=0, k1=4.

[0174] 18D shows a case where the number of ports is 28 (7 CDM groups), and "101010" is notified as the first bitmap, and "101101" is notified as the second bitmap. In this case, the UE determines that the frequency domain positions of the CSI-RS (each component resource) in the first start symbol are k0=2, k1=6, and k2=10. On the other hand, the UE determines that the frequency domain positions of the CSI-RS (each component resource) in the second start symbol are k0=0, k1=4, k2=6, and k3=10.

[0175] 18A-18D show the case where multiple bitmaps are notified to the UE, but this is not limiting. Instead of notifying the second bitmap (e.g., frequencyDomainAllocation2), k bars (e.g., k) corresponding to different start symbols may be defined / set separately.

[0176] In this case, a new row may be introduced into the CSI-RS position table, and the definition of k / k in the new row may be different from that of the existing row. For example, a configuration in which a predetermined offset is added to k corresponding to the first start symbol may be applied to the second start symbol. The predetermined offset may be, for example, a modulo operation.

[0177] 19A shows an example of a CSI-RS resource mapping pattern corresponding to a new row #x. This example shows a case where the number of ports is 24, the densities are 1, 0.5, and cdm4-FD2-TD2. The frequency domain corresponding to the first start symbol is defined by k0, k1, and k2, and the frequency domain corresponding to the second start symbol is defined by (k0+2)mod2, (k1+2)mod2, and (k2+2)mod2.

[0178] The network (e.g., a base station) may indicate a bitmap to the UE as an upper layer parameter (e.g., frequencyDomainAllocation) related to frequency domain allocation of CSI-RS. Here, a case is shown in which "101010" is indicated as the bitmap corresponding to row #x.

[0179] The UE selects a row (here, row #x) corresponding to the CSI-RS based on higher layer parameters including a bitmap notified by the base station, and then determines the frequency domain location of the CSI-RS. The UE may determine the row based on the port / density / CDM type notified by the higher layer parameters, or information specifying the row may be notified to the UE by the higher layer parameters.

[0180] For row#x, UE is [b5……b0],k i-1= 2f(i) and the bitmap (101010), it is determined that k0 = 2, k1 = 6, and k2 = 10, and the positions of the frequency domain resources of the CSI-RS (each component resource) are determined (see FIG. 19B). Here, the positions of the frequency domain resources corresponding to the first start symbol (the frequency domain resources corresponding to CDM groups 0, 1, and 2, respectively) are k0 = 2, k1 = 6, and k2 = 10, and the positions of the frequency domain resources corresponding to the second start symbol (the frequency domain resources corresponding to CDM groups 3, 4, and 5, respectively) are (k0 + 2) mod 12 = 4, (k1 + 2) mod 12 = 8, and (k2 + 2) mod 12 = 0.

[0181] Note that aspect 2-3 may be applied in combination with at least one of aspect 2-1 and aspect 2-2.

[0182] <<Aspect 2-2 + Aspect 2-3>> When the frequency domain density value of the CSI-RS resource is less than 1 and multiple (e.g., two) starting symbols are configured in one slot, mapping of different ports / CDM groups to multiple RBs (or different RBs) is supported, and different frequency domain resource allocations may be supported for different starting symbols.

[0183] 20A shows an example of a CSI-RS resource mapping pattern corresponding to row #14. Here, the number of ports is 24, and the densities are 1, 0.5, and cdm4-FD2-TD2. Also shown is a case where the frequency domains corresponding to the first start symbol (e.g., l0) and the second start symbol (e.g., l1) are indicated by k0, k1, and k2. The density of the frequency domains to be configured may be specified by higher layer signaling.

[0184] The network (e.g., a base station) may notify the UE of a first frequency domain resource allocation (e.g., frequencyDomainAllocation / first bitmap) and a second frequency domain resource allocation (e.g., frequencyDomainAllocation2 / second bitmap) as higher layer parameters related to frequency domain allocation of CSI-RS.

[0185] The UE selects a row (here, row #14) corresponding to the CSI-RS based on higher layer parameters including a bitmap notified by the base station, and then determines the frequency domain location of the CSI-RS. The UE may determine the row based on the port / density / CDM type notified by the higher layer parameters, or information specifying the row may be notified to the UE by the higher layer parameters.

[0186] When the frequency domain density is 0.5, the UE uses [b11……b0],k i-1 = 2f(i), the first bitmap, and the second bitmap, determine the frequency domain location (k0, k1, k2) of the CSI-RS (each component resource) in each starting symbol (see Figure 20B).

[0187] 20B shows a case where the number of ports is 24 (6 CDM groups), and "000000101010" is notified as the first bitmap, and "010101000000" is notified as the second bitmap. In this case, the UE determines that the frequency domain positions of the CSI-RS (each component resource) in the first start symbol are k0=2, k1=6, and k2=10. On the other hand, the UE determines that the frequency domain positions of the CSI-RS (each component resource) in the second start symbol are k0=12, k1=16, and k2=20.

[0188] Here, the case is shown where CDM groups 0, 1, and 2 corresponding to the first start symbol are mapped to the first RB, and CDM groups 3, 4, and 5 corresponding to the second start symbol are mapped to the second RB.

[0189] In this way, bitmap indication of different frequency domain allocations is supported for different starting symbols, and when the frequency domain density is less than 1, it is possible to map multiple ports with different frequency domain resource allocations to different RBs.

[0190] 20A and 20B show the case where multiple bitmaps are notified to the UE, but this is not limiting. Alternatively, k bars (e.g., k) corresponding to different start symbols may be defined / set separately without notifying the second bitmap (e.g., frequencyDomainAllocation2).

[0191] <<Aspect 2-1 + Aspect 2-2 + Aspect 2-3>> When a new frequency domain density (e.g., ρ_new = 1 / N or M / N) different from that of existing systems is applied as the frequency domain density value of CSI-RS resources and multiple (e.g., two) starting symbols are set within one slot, mapping of different ports / CDM groups to multiple RBs (or different RBs) is supported, and different frequency domain resource allocations may be supported for different starting symbols.

[0192] 21A shows an example of a CSI-RS resource mapping pattern corresponding to row #14. Here, the number of ports is 24, and the densities are 1, 0.5, 1 / 4, and cdm4-FD2-TD2. Also shown is a case where the frequency domains corresponding to the first start symbol (e.g., l0) and the second start symbol (e.g., l1) are indicated by k0, k1, and k2. The density of the frequency domains to be configured may be specified by higher layer signaling.

[0193] The network (e.g., a base station) may notify the UE of a first frequency domain resource allocation (e.g., frequencyDomainAllocation / first bitmap) and a second frequency domain resource allocation (e.g., frequencyDomainAllocation2 / second bitmap) as higher layer parameters related to frequency domain allocation of CSI-RS.

[0194] The UE selects a row (here, row #14) corresponding to the CSI-RS based on higher layer parameters including a bitmap notified by the base station, and then determines the frequency domain location of the CSI-RS. The UE may determine the row based on the port / density / CDM type notified by the higher layer parameters, or information specifying the row may be notified to the UE by the higher layer parameters.

[0195] When the frequency domain density is 1 / 4, the UE receives [b6*N-1,b6*N-2……b0],k i-1 = 2f(i), the first bitmap, and the second bitmap, determine the frequency domain location (k0, k1, k2) of the CSI-RS (each component resource) in each starting symbol (see Figure 21B).

[0196] 21B shows a case where the number of ports is 24 (6 CDM groups), and "000000,100000,001000,000010" is reported as the first bitmap, and "100000,000001,000000,100000" is reported as the second bitmap. In this case, the UE determines that the frequency domain position of the CSI-RS (each component resource) in the first start symbol is k0=2, k1=18, k2=34. On the other hand, the UE determines that the frequency domain position of the CSI-RS (each component resource) in the second start symbol is k0=10, k1=24, k2=46.

[0197] Here, CDM groups 0, 1, and 2 corresponding to the first start symbol are mapped to different RBs, and CDM groups 3, 4, and 5 corresponding to the second start symbol are mapped to different RBs. Furthermore, frequency domain resources for CDM groups 0, 1, and 2 corresponding to the first start symbol and frequency domain resources for CDM groups 3, 4, and 5 corresponding to the second start symbol are configured separately.

[0198] In this way, different frequency domain resource allocations are supported for different starting symbols (or for each starting symbol), and when the frequency domain density is less than 1 (e.g., ρ_new = 1 / N or M / N), it is possible to map multiple ports with different frequency domain resource allocations to different RBs.

[0199] 21A and 21B show a case where multiple bitmaps are notified to the UE, but this is not limiting. Instead of notifying the second bitmap (e.g., frequencyDomainAllocation2), k bars (e.g., k) corresponding to different start symbols may be defined / set separately.

[0200] Which of the aspects 2-1 to 2-3 is applied may be configured in the UE by higher layer parameters, may be reported by the UE as UE capability information, or may be defined by specifications. Alternatively, which of the aspects 2-1 to 2-3 is applied may be determined in consideration of the UE capability information reported from the UE and the higher layer parameters configured in the UE.

[0201] (UE capability information) In the above first and second embodiments, the following UE capabilities may be set. Note that the following UE capabilities may be interpreted as parameters (e.g., upper layer parameters) set in the UE from the network (e.g., base station).

[0202] The operation of each embodiment may be applied only if the corresponding UE capability is reported.

[0203] UE capability information may be defined regarding whether or not the time domain periodicity of the CSI-RS supports a value greater than a predetermined value.

[0204] UE capability information may be defined regarding whether or not a predetermined value (e.g., a new value not supported in existing systems) is supported for the frequency domain density of CSI-RS.

[0205] UE capability information may be defined regarding whether the UE supports mapping different ports / CDM groups to different RBs.

[0206] The first and second embodiments may be applied to a UE that supports / reports at least one of the above-mentioned UE capabilities, or may be applied to a UE configured by a network.

[0207] (wireless communication system) The 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 thereof.

[0208] 22 is a diagram illustrating an example of a schematic configuration of a wireless communication system according to an embodiment. The wireless communication system 1 may be a system that realizes communication using Long Term Evolution (LTE) or 5th generation mobile communication system New Radio (5G NR) specified by the Third Generation Partnership Project (3GPP).

[0209] 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.

[0210] 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.

[0211] The wireless communication system 1 may support dual connectivity between multiple base stations within the same RAT (for example, dual connectivity in which both the MN and the SN are NR base stations (gNBs) (NR-NR Dual Connectivity (NN-DC))).

[0212] 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 located within the macrocell C1 and form small cells C2 that are smaller than the macrocell C1. A user terminal 20 may be located within at least one of the cells. The locations and numbers of the cells and user terminals 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.

[0213] 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).

[0214] 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)). The macro cell C1 may be included in FR1, and the small cell C2 may be included in FR2. For example, FR1 may be a frequency band of 6 GHz or less (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 be a frequency band higher than FR2.

[0215] Furthermore, the user terminal 20 may perform communication using at least one of Time Division Duplex (TDD) and Frequency Division Duplex (FDD) in each CC.

[0216] The multiple base stations 10 may be connected by wire (for example, optical fiber conforming to the Common Public Radio Interface (CPRI), an X2 interface, or the like) or wirelessly (for example, NR communication). For example, when NR communication is used as a backhaul between the base stations 11 and 12, the base station 11 corresponding to the upper station may be called an Integrated Access Backhaul (IAB) donor, and the base station 12 corresponding to the relay station (relay) may be called an IAB node.

[0217] The base station 10 may be connected to the core network 30 directly or via another base station 10. 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), and the like.

[0218] The user terminal 20 may be a terminal compatible with at least one of communication methods such as LTE, LTE-A, and 5G.

[0219] An Orthogonal Frequency Division Multiplexing (OFDM)-based radio access scheme may be used in the radio communication system 1. For example, 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), or the like may be used in at least one of the downlink (DL) and uplink (UL).

[0220] The radio access scheme may also be called a waveform. Note that in the wireless communication system 1, other radio access schemes (for example, other single-carrier transmission schemes, other multi-carrier transmission schemes) may be used as the UL and DL radio access schemes.

[0221] 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.

[0222] Furthermore, 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.

[0223] The PDSCH transmits user data, higher layer control information, System Information Block (SIB), etc. The PUSCH may transmit user data, higher layer control information, etc. Furthermore, the PBCH may transmit Master Information Block (MIB).

[0224] Lower layer control information may be transmitted by the PDCCH. The lower layer control information may include, for example, Downlink Control Information (DCI) including scheduling information for at least one of the PDSCH and the PUSCH.

[0225] Note that the DCI for scheduling the PDSCH may be referred to as a DL assignment, a DL DCI, etc., and the DCI for scheduling the PUSCH may be referred to as an UL grant, a UL DCI, etc. Note that the PDSCH may be interpreted as DL data, and the PUSCH may be interpreted as UL data.

[0226] A control resource set (CORESET) and a search space may be used to detect the PDCCH. The CORESET corresponds to resources to search for DCI. The search space corresponds to a search region and a search method for PDCCH candidates. One CORESET may be associated with one or more search spaces. The UE may monitor a CORESET associated with a certain search space based on the search space configuration.

[0227] One search space may correspond to PDCCH candidates corresponding to one or more aggregation levels. One or more search spaces may be called 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 the present disclosure may be read interchangeably.

[0228] The PUCCH may transmit uplink control information (UCI) including at least one of channel state information (CSI), acknowledgement information (which may be called, for example, Hybrid Automatic Repeat reQuest ACKnowledgement (HARQ-ACK), ACK / NACK, etc.), and scheduling request (SR). The PRACH may transmit a random access preamble for establishing a connection with a cell.

[0229] In the present disclosure, downlink, uplink, etc. may be expressed without adding "link." Also, various channels may be expressed without adding "Physical" to the beginning.

[0230] 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, 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 as DL-RS.

[0231] 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 the SS (PSS, SSS) and the PBCH (and DMRS for the PBCH) may be referred to as an SS / PBCH block, an SS Block (SSB), or the like. Note that the SS, SSB, and the like may also be referred to as reference signals.

[0232] Furthermore, in the wireless communication system 1, a 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).

[0233] (base station) 23 is a diagram showing an example of the 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 the base station may include one or more of each of the control unit 110, the transceiver unit 120, the transceiver antenna 130, and the transmission line interface 140.

[0234] In this example, the functional blocks of the characteristic parts of the present embodiment are mainly shown, and it may be assumed that the base station 10 also has other functional blocks necessary for wireless communication. Some of the processing of each unit described below may be omitted.

[0235] The control unit 110 performs overall control of the base station 10. The control unit 110 can be configured from a controller, a control circuit, and the like that are explained based on common understanding in the technical field to which the present disclosure relates.

[0236] 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 to be transmitted as signals, control information, sequences, etc., and transfer them to the transceiver unit 120. The control unit 110 may perform call processing (setting up, releasing, etc.) of communication channels, status management of the base station 10, management of radio resources, etc.

[0237] 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 configured with 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 common understanding in the technical field related to the present disclosure.

[0238] The transmitting / receiving unit 120 may be configured as an integrated transmitting / receiving unit, or may be composed of a transmitting unit and a receiving unit. The transmitting unit may be composed of a transmission processing unit 1211 and an RF unit 122. The receiving unit may be composed of a reception processing unit 1212, an RF unit 122, and a measurement unit 123.

[0239] The transmitting and receiving antenna 130 can be configured from an antenna described based on common understanding in the technical field to which the present disclosure pertains, such as an array antenna.

[0240] 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.

[0241] The transceiver 120 may form at least one of a transmission beam and a reception beam using digital beamforming (for example, precoding), analog beamforming (for example, phase rotation), or the like.

[0242] 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, control information, etc. obtained from the control unit 110, and generate a bit string to be transmitted.

[0243] 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.

[0244] The transmitting / receiving unit 120 (RF unit 122) may perform modulation to a radio frequency band, filtering, amplification, etc. on the baseband signal, and transmit the radio frequency band signal via the transmitting / receiving antenna .

[0245] On the other hand, the transmitting / receiving unit 120 (RF unit 122) may perform amplification, filtering, demodulation to a baseband signal, etc. on the radio frequency band signal received by the transmitting / receiving antenna .

[0246] 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, thereby acquiring user data, etc.

[0247] 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.

[0248] The transmission path interface 140 may transmit and receive signals (backhaul signaling) between devices included in the core network 30, other base stations 10, etc., and may acquire and transmit user data (user plane data), control plane data, etc. for the user terminal 20.

[0249] The transmitting section and receiving section of the base station 10 in the present disclosure may be configured by at least one of the transmitting / receiving section 120, the transmitting / receiving antenna 130, and the transmission path interface 140.

[0250] The transceiver 120 may transmit, for the channel state information reference signal, at least one of information on time domain resources indicated in a time unit longer than a slot and information on frequency domain resources supporting a frequency domain density at least smaller than 0.5. The controller 110 may control mapping of the channel state information reference signal corresponding to at least one of the information on time domain resources and the information on frequency domain resources.

[0251] Alternatively, the transceiver 120 may transmit information regarding the frequency domain density of the channel state information reference signal. If the frequency domain density is less than 1, the controller 110 may control the transmission of the channel state information reference signal in which at least one mapping of different ports and different CDM groups is supported for multiple resource blocks.

[0252] Alternatively, the transceiver 120 may transmit information about the start symbol of the channel state information reference signal. When a slot includes multiple start symbols, the controller 110 may control the transmission of the channel state information reference signal in which frequency domain resources are set separately for each start symbol.

[0253] (user terminal) 24 is a diagram showing an example of the configuration of a user terminal according to one embodiment. The user terminal 20 includes a control unit 210, a transceiver unit 220, and a transceiver antenna 230. Note that the user terminal 20 may include one or more of each of the control unit 210, the transceiver unit 220, and the transceiver antenna 230.

[0254] Note that this example mainly shows functional blocks of the characteristic parts of the present embodiment, and it may be assumed that the user terminal 20 also has other functional blocks necessary for wireless communication. Some of the processing of each unit described below may be omitted.

[0255] The control unit 210 performs overall control of the user terminal 20. The control unit 210 can be configured from a controller, a control circuit, and the like that are explained based on common understanding in the technical field to which the present disclosure relates.

[0256] The control unit 210 may control signal generation, mapping, etc. The control unit 210 may also control transmission and reception, measurement, etc. using the transceiver unit 220 and the transceiver antenna 230. The control unit 210 may generate data, control information, sequences, etc. to be transmitted as signals, and transfer them to the transceiver unit 220.

[0257] 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 configured from 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 common understanding in the technical field related to the present disclosure.

[0258] The transmitting / receiving unit 220 may be configured as an integrated transmitting / receiving unit, or may be composed of a transmitting unit and a receiving unit. The transmitting unit may be composed of a transmission processing unit 2211 and an RF unit 222. The receiving unit may be composed of a reception processing unit 2212, an RF unit 222, and a measurement unit 223.

[0259] The transmitting / receiving antenna 230 can be configured as an antenna described based on common understanding in the technical field to which the present disclosure pertains, such as an array antenna.

[0260] 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.

[0261] The transceiver 220 may form at least one of a transmission beam and a reception beam using digital beamforming (for example, precoding), analog beamforming (for example, phase rotation), or the like.

[0262] The transceiver 220 (transmission processing unit 2211) may perform PDCP layer processing, RLC layer processing (e.g., RLC retransmission control), MAC layer processing (e.g., HARQ retransmission control), etc. on data, control information, etc. obtained from the control unit 210, and generate a bit string to be transmitted.

[0263] 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.

[0264] Whether or not to apply DFT processing may be based on the setting 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 transmission processing to transmit the channel using a DFT-s-OFDM waveform, and when transform precoding is not enabled, the transceiver unit 220 may not perform DFT processing as the transmission processing.

[0265] The transmitting / receiving unit 220 (RF unit 222) may perform modulation to a radio frequency band, filtering, amplification, etc. on the baseband signal, and transmit the radio frequency band signal via the transmitting / receiving antenna 230.

[0266] On the other hand, the transmitting / receiving unit 220 (RF unit 222) may perform amplification, filtering, demodulation to a baseband signal, etc. on the radio frequency band signal received by the transmitting / receiving antenna 230.

[0267] The transceiver 220 (reception processing unit 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.

[0268] The transceiver 220 (measurement unit 223) may perform measurements on the received signal. For example, the measurement unit 223 may perform RRM measurement, CSI measurement, 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.

[0269] The transmitting section and receiving section of the user terminal 20 in the present disclosure may be configured by at least one of the transmitting / receiving section 220 and the transmitting / receiving antenna 230.

[0270] The transceiver 220 may receive, for the channel state information reference signal, at least one of information on time domain resources indicated in time units longer than a slot and information on frequency domain resources supporting a frequency domain density at least smaller than 0.5. The controller 210 may control reception of the channel state information reference signal based on at least one of the information on time domain resources and the information on frequency domain resources (aspect 2-1 of the first embodiment / second embodiment).

[0271] The information on the time domain resource may include information on an offset indicated in a time unit longer than a slot. The information on the frequency domain resource may include information on one or more resource blocks to which the channel state information reference signal is allocated among a plurality of resource blocks. The information on the one or more resource blocks to which the channel state information reference signal is allocated may be indicated in a bitmap format.

[0272] Alternatively, the transceiver 220 may receive information regarding the frequency domain density of the channel state information reference signal. If the frequency domain density is less than 1, the controller 210 may control reception of the channel state information reference signal in which at least one mapping of different ports and different CDM groups for multiple resource blocks is supported (aspect 2-2 of the second embodiment).

[0273] The transceiver 220 may receive frequency domain allocation information of the channel state reference signal, the frequency domain allocation information including a bitmap indicating subcarriers in a plurality of resource blocks. The size of the bitmap may be variable depending on the frequency domain density. The transceiver 220 may receive the frequency domain allocation information of the channel state reference signal, and the controller 210 may control reception of the channel state information reference signal by applying a predetermined offset to the frequency domain allocation information of the channel state reference signal.

[0274] Alternatively, the transceiver 220 may receive information about the start symbol of the channel state information reference signal. When a slot includes multiple start symbols, the controller 210 may control reception of the channel state information reference signal in which frequency domain resources are set separately for each start symbol (aspect 2-3 of the second embodiment).

[0275] The transceiver 220 may receive a plurality of bitmaps indicating frequency domain allocation of channel state information corresponding to each start symbol. When a first start symbol and a second start symbol are included in a slot, a frequency domain position of the channel state reference signal corresponding to the second start symbol may be offset from a frequency domain position of the channel state reference signal corresponding to the first start symbol. The number of CDM groups mapped to each start symbol may be set differently.

[0276] (Hardware configuration) The block diagrams used to explain the above embodiments show functional blocks. These functional blocks (components) are realized by any combination of at least one of hardware and software. Furthermore, the method for realizing each functional block is not particularly limited. That is, each functional block may be realized using a single device that is physically or logically coupled, or may be realized using two or more physically or logically separated devices that are directly or indirectly connected (for example, using wires, wirelessly, etc.) and these multiple devices. The functional block may also be realized by combining the single device or multiple devices with software.

[0277] Here, the functions include, but are not limited to, judgment, determination, judgment, calculation, computation, processing, derivation, investigation, search, confirmation, reception, transmission, output, access, resolution, selection, election, establishment, comparison, assumption, expectation, deeming, broadcasting, notifying, communicating, forwarding, configuring, reconfiguring, allocating, mapping, and assignment. For example, a functional block (component) that performs transmission may be called a transmitting unit, transmitter, etc. As mentioned above, the implementation method of each is not particularly limited.

[0278] For example, a base station, a user terminal, etc. according to an embodiment of the present disclosure may function as a computer that performs processing of the wireless communication method of the present disclosure. Fig. 25 is a diagram illustrating an example of the hardware configuration of a base station and a user terminal according to an embodiment. The above-described 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.

[0279] In this disclosure, terms such as apparatus, circuit, device, section, unit, etc. may be read interchangeably. 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 drawings, or may be configured to exclude some of the devices.

[0280] 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, serially, or in other ways. Furthermore, processor 1001 may be implemented by one or more chips.

[0281] Each function in the base station 10 and the user terminal 20 is realized, for example, by loading predetermined software (programs) onto hardware such as a processor 1001 and a memory 1002, causing the processor 1001 to perform calculations, control communication via the communication device 1004, and control at least one of reading and writing data in the memory 1002 and the storage 1003.

[0282] The processor 1001, for example, runs 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, a register, etc. For example, at least a part of the above-mentioned control unit 110 (210), transmission / reception unit 120 (220), etc. may be realized by the processor 1001.

[0283] The processor 1001 also reads 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 in accordance with these. The programs used are those that cause a computer to execute at least some of the operations described in the above-described 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 the other functional blocks may be realized in a similar manner.

[0284] The memory 1002 is a computer-readable recording medium and may be configured by at least one of, for example, a read-only memory (ROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), a random access memory (RAM), or other suitable storage medium. The memory 1002 may also be referred to as a register, a cache, a main memory, or the like. The memory 1002 may store executable programs (program codes), software modules, and the like for implementing a wireless communication method according to an embodiment of the present disclosure.

[0285] Storage 1003 is a computer-readable recording medium and may be constituted by at least one of, for example, a flexible disk, a floppy disk, a magneto-optical disk (e.g., a compact disc (e.g., a Compact Disc ROM (CD-ROM)), a digital versatile disc, a Blu-ray disc), a removable disk, a hard disk drive, a smart card, a flash memory device (e.g., a card, stick, key drive), a magnetic stripe, a database, a server, or other suitable storage medium. Storage 1003 may also be referred to as a secondary storage device.

[0286] The communication device 1004 is hardware (transmission / reception device) for communicating between computers via at least one of a wired network and a wireless network, and is also referred to as, for example, a network device, a network controller, a network card, or a communication module. 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 frequency division duplex (FDD) and time division duplex (TDD). For example, the above-mentioned transmission / reception unit 120 (220), transmission / reception antenna 130 (230), etc. may be realized by the communication device 1004. The transmission / reception unit 120 (220) may be implemented as a transmission unit 120a (220a) and a reception unit 120b (220b) that are physically or logically separated.

[0287] The input device 1005 is an input device (for example, a keyboard, a mouse, a microphone, a switch, a button, a sensor, etc.) that receives input from the outside. The output device 1006 is an output device (for example, a display, a speaker, a light emitting diode (LED) lamp, etc.) that outputs to the outside. The input device 1005 and the output device 1006 may be integrated into one device (for example, a touch panel).

[0288] Furthermore, each device, such as the processor 1001 and the 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.

[0289] 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 such hardware. For example, the processor 1001 may be implemented using at least one of these pieces of hardware.

[0290] (Variation) Note that terms explained in the present disclosure and terms necessary for understanding the present 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 interchangeable. A signal may also be a message. A reference signal may be abbreviated as RS, and may also be called a pilot, pilot signal, etc. depending on the applicable standard. A component carrier (CC) may also be called a cell, frequency carrier, carrier frequency, etc.

[0291] 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.

[0292] Here, the numerology may be a communication parameter applied to at least one of transmission and reception of a signal or channel, and may indicate at least one of, for example, a subcarrier spacing (SCS), a bandwidth, a symbol length, a cyclic prefix length, a transmission time interval (TTI), the number of symbols per TTI, a radio frame structure, a specific filtering process performed by a transceiver in the frequency domain, and a specific windowing process performed by a transceiver in the time domain.

[0293] A slot may be composed of one or more symbols in the time domain (such as an Orthogonal Frequency Division Multiplexing (OFDM) symbol or a Single Carrier Frequency Division Multiple Access (SC-FDMA) symbol), and may be a time unit based on numerology.

[0294] 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.

[0295] A radio frame, a subframe, a slot, a minislot, and a symbol all represent time units for transmitting signals. The radio frame, the subframe, the slot, the minislot, and the symbol may be referred to by other names corresponding to the radio frame, the subframe, the slot, the minislot, and the symbol. Note that the time units such as a frame, a subframe, a slot, a minislot, and a symbol in the present disclosure may be interchangeable.

[0296] For example, one subframe may be referred to as a TTI, or multiple consecutive subframes may be referred to as a TTI, or one slot or one minislot may be referred to as a TTI. That is, at least one of a subframe and a TTI may be a subframe (1 ms) in existing LTE, a period shorter than 1 ms (for example, 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.

[0297] Here, TTI refers to, for example, the smallest time unit for scheduling in wireless communication. For example, in an LTE system, a base station performs scheduling to allocate radio resources (such as frequency bandwidth and transmission power that can be used by each user terminal) to each user terminal in TTI units. However, the definition of TTI is not limited to this.

[0298] The TTI may be a transmission time unit for a channel-encoded 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) to which a transport block, a code block, a code word, etc. is actually mapped may be shorter than the TTI.

[0299] 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 for scheduling. Also, the number of slots (minislots) constituting the minimum time unit for scheduling may be controlled.

[0300] A TTI having a time length of 1 ms may be called a regular TTI (TTI in 3GPP Rel. 8-12), normal TTI, long TTI, regular subframe, normal subframe, long subframe, slot, etc. A TTI shorter than a regular TTI may be called a shortened TTI, short TTI, partial or fractional TTI, shortened subframe, short subframe, minislot, subslot, slot, etc.

[0301] In addition, 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.

[0302] A resource block (RB) is a resource allocation unit in the time domain and the 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, for example, 12. The number of subcarriers included in an RB may also be determined based on numerology.

[0303] In addition, an RB may include one or more symbols in the time domain and may have a length of one slot, one minislot, one subframe, or one TTI. One TTI, one subframe, etc. may each be composed of one or more resource blocks.

[0304] Note that one or more RBs may also be called a physical resource block (PRB), a sub-carrier group (SCG), a resource element group (REG), a PRB pair, an RB pair, etc.

[0305] Furthermore, a resource block may be composed of one or more resource elements (REs). For example, one RE may be a radio resource region of one subcarrier and one symbol.

[0306] A Bandwidth Part (BWP), which may also be referred to as a fractional 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 their index relative to a common reference point of the carrier. PRBs may be defined in a given BWP and numbered within that BWP.

[0307] The BWP may include an UL BWP (a BWP for UL) and a DL BWP (a BWP for DL). One or more BWPs may be configured for a UE within one carrier.

[0308] 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 the terms "cell," "carrier," etc. in this disclosure may be read as "BWP."

[0309] The above-described structures of radio frames, subframes, slots, minislots, symbols, etc. 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, the number of symbols in a TTI, the symbol length, the cyclic prefix (CP) length, etc. may be changed in various ways.

[0310] Furthermore, the information, parameters, etc. described in the present disclosure may be expressed using absolute values, may be expressed using relative values ​​from a predetermined value, or may be expressed using other corresponding information. For example, a radio resource may be indicated by a predetermined index.

[0311] The names used for parameters and the like in this disclosure are not intended to be limiting in any way. Furthermore, the mathematical expressions 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 therefore the various names assigned to these various channels and information elements are not intended to be limiting in any way.

[0312] The information, signals, etc. described in this disclosure may be represented using any of a variety of different technologies. For example, 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.

[0313] Furthermore, 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.

[0314] Input and output information, signals, etc. may be stored in a specific location (for example, memory) or may be managed using a management table. Input and output information, signals, etc. may be overwritten, updated, or added. Output information, signals, etc. may be deleted. Input information, signals, etc. may be transmitted to another device.

[0315] Notification of information is not limited to the aspects / embodiments described in the present disclosure, and may be performed using other methods. For example, notification of information in the present disclosure may be performed by physical layer signaling (e.g., Downlink Control Information (DCI) and Uplink Control Information (UCI)), higher layer signaling (e.g., Radio Resource Control (RRC) signaling, broadcast information (Master Information Block (MIB) and System Information Block (SIB)), Medium Access Control (MAC) signaling), other signals, or a combination thereof.

[0316] Note that 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. Furthermore, the RRC signaling may be called an RRC message, such as an RRC connection setup message or an RRC connection reconfiguration message. Furthermore, the MAC signaling may be notified using, for example, a MAC Control Element (CE).

[0317] Furthermore, notification of specified information (e.g., notification that "it is X") is not limited to explicit notification, but may be made implicitly (e.g., by not notifying the specified information or by notifying other information).

[0318] The determination may be made by a value represented by one bit (0 or 1), by a Boolean value represented by true or false, or by a comparison of numerical values ​​(e.g., comparison with a predetermined value).

[0319] 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.

[0320] Software, instructions, information, etc. may also be transmitted or received over a transmission medium. For example, if software is transmitted from a website, server, or other remote source using wired technologies (such as coaxial cable, fiber optic cable, twisted pair, Digital Subscriber Line (DSL)), and / or wireless technologies (such as infrared, microwave), then these wired and / or wireless technologies are included within the definition of transmission media.

[0321] As used in this disclosure, the terms "system" and "network" may be used interchangeably. A "network" may refer to devices included in the network (e.g., base stations).

[0322] In the present 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," "antenna port group," "layer," "number of layers," "rank," "resource," "resource set," "resource group," "beam," "beam width," "beam angle," "antenna," "antenna element," "panel," etc. may be used interchangeably.

[0323] 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.

[0324] A base station can accommodate one or more (e.g., three) cells. When a base station accommodates multiple cells, the overall coverage area of ​​the base station can be divided into multiple smaller areas, and each smaller area can be provided with communication service by a base station subsystem (e.g., a small indoor base station (Remote Radio Head (RRH))). The term "cell" or "sector" refers to a part or the entire coverage area of ​​a base station and / or base station subsystem that provides communication service within this coverage.

[0325] In this disclosure, the terms "Mobile Station (MS)," "user terminal," "User Equipment (UE)," "terminal," etc. may be used interchangeably.

[0326] 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.

[0327] 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. Note that 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.

[0328] The mobile body is a movable object that can move at any speed and naturally includes cases where the mobile body is stationary. Examples of the mobile body include, but are not limited to, vehicles, transport vehicles, automobiles, motorcycles, bicycles, connected cars, excavators, bulldozers, wheel loaders, dump trucks, forklifts, trains, buses, handcars, rickshaws, ships and other watercraft, airplanes, rockets, satellites, drones, multicopters, quadcopters, balloons, and objects mounted thereon. The mobile body may also be a mobile body that moves autonomously based on an operation command.

[0329] The mobile object may be a vehicle (e.g., a car, an airplane, etc.), an unmanned mobile 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.

[0330] 26 is a diagram showing an example of a vehicle according to an embodiment. A 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, axles 48, an electronic control unit 49, various sensors (including a current sensor 50, an RPM 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.

[0331] The drive unit 41 is configured with 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 handle) 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.

[0332] 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).

[0333] The signals from the various sensors 50-58 include a current signal from a current sensor 50 that senses the current of the motor, a rotation speed signal of the front wheels 46 / rear wheels 47 obtained by a rotation speed sensor 51, an air pressure signal of the front wheels 46 / rear wheels 47 obtained by an air pressure sensor 52, a vehicle speed signal obtained by a vehicle speed sensor 53, an acceleration signal obtained by an acceleration sensor 54, a depression amount signal of the accelerator pedal 43 obtained by an accelerator pedal sensor 55, a depression amount signal of the brake pedal 44 obtained by a brake pedal sensor 56, an operation signal of the shift lever 45 obtained by a shift lever sensor 57, and a detection signal for detecting obstacles, vehicles, pedestrians, etc. obtained by an object detection sensor 58.

[0334] The information service unit 59 is composed of various devices, such as a car navigation system, an audio system, speakers, a display, a television, and a radio, for providing (outputting) various information such as driving information, traffic information, and entertainment information, and one or more ECUs for controlling these devices. The information service unit 59 uses information acquired from external devices via the communication module 60 or the like to provide various information / services (for example, multimedia information / multimedia services) to the occupants of the vehicle 40.

[0335] The information service unit 59 may include input devices (e.g., keyboards, mice, microphones, switches, buttons, sensors, touch panels, etc.) that accept input from the outside, and may also include output devices (e.g., displays, speakers, LED lamps, touch panels, etc.) that output to the outside.

[0336] The driving assistance system unit 64 is configured with various devices that provide functions for preventing accidents and reducing the driver's driving burden, such as millimeter-wave radar, Light Detection and Ranging (LiDAR), cameras, positioning locators (e.g., Global Navigation Satellite System (GNSS)), map information (e.g., High Definition (HD) maps, Autonomous Vehicle (AV) maps), gyro systems (e.g., Inertial Measurement Units (IMUs), Inertial Navigation Systems (INSs)), Artificial Intelligence (AI) chips, and AI processors, as well as 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 driving assistance functions or autonomous driving functions.

[0337] 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 to and from 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, which are provided in the vehicle 40.

[0338] 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. Furthermore, the communication module 60 may be, for example, at least one of the above-mentioned base station 10 and user terminal 20 (or may function as at least one of the base station 10 and user terminal 20).

[0339] The communication module 60 may transmit at least one of signals from the above-mentioned various sensors 50-58 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-mentioned input.

[0340] The communication module 60 receives various information (traffic information, traffic signal information, vehicle distance information, etc.) transmitted from external devices 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 received by the communication module 60 (or data / information decoded from the PDSCH)).

[0341] Furthermore, the communication module 60 stores various information received from external devices in a memory 62 that can be used by the microprocessor 61. Based on the information stored in the 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 in the vehicle 40.

[0342] Furthermore, a base station in the present disclosure may be read as a user terminal. For example, the aspects / embodiments 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) or Vehicle-to-Everything (V2X)). 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, terms such as uplink channel and downlink channel may be read as sidelink channel.

[0343] Similarly, the user terminal in the present disclosure may be read as a base station, in which case the base station 10 may be configured to have the functions of the user terminal 20 described above.

[0344] In the present disclosure, an operation described as being performed by a base station may be performed by its upper node in some cases. It is apparent that in a network including one or more network nodes having a base station, various operations performed for communication with a terminal 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) and a Serving-Gateway (S-GW)), or a combination thereof.

[0345] Each aspect / embodiment described in this disclosure may be used alone, in combination, or switched depending on the implementation. Furthermore, the order of the processing procedures, sequences, flowcharts, etc. of each aspect / embodiment described in this disclosure may be changed unless inconsistent. For example, the methods described in this disclosure present elements of various steps using an example order, and are not limited to the specific order presented.

[0346] Each aspect / embodiment described in the present disclosure may be a technology other than 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 number)), Future Radio Access (FRA), New-Radio 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 The present invention may be applied to systems that use 802.20, Ultra-WideBand (UWB), Bluetooth (registered trademark), or other appropriate wireless communication methods, or to next-generation systems that are expanded, modified, created, or defined based on these. It may also be applied to a combination of multiple systems (e.g., a combination of LTE or LTE-A and 5G).

[0347] 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."

[0348] As used in this disclosure, any reference to an element using a designation such as "first," "second," etc. 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 a second element does not imply that only two elements may be employed or that the first element must in some way precede the second element.

[0349] 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 up in a table, database, or another data structure), ascertaining, etc.

[0350] Additionally, "determining" may be considered to be "determining" receiving (e.g., receiving information), transmitting (e.g., sending information), input, output, accessing (e.g., accessing data in memory), etc.

[0351] Also, "decision" may be considered to be "deciding" resolving, selecting, choosing, establishing, comparing, etc. In other words, "decision" may be considered to be "deciding" on some action.

[0352] Furthermore, "judgment (decision)" may be interpreted as "assuming," "expecting," "considering," or the like.

[0353] As used in this disclosure, the terms "connected," "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 elements may be physical, logical, or a combination thereof. For example, "connected" may be read as "access."

[0354] 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, etc., as well as using electromagnetic energy having wavelengths in the radio frequency range, microwave range, light (both visible and invisible) range, etc., as some non-limiting and non-exhaustive examples.

[0355] In the present 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 "coupled" may also be interpreted in the same way as "different."

[0356] When used in this disclosure, the terms "include," "including," and variations thereof are intended to be inclusive, similar to the term "comprising." Furthermore, when used in this disclosure, the term "or" is not intended to be an exclusive or.

[0357] In this disclosure, where articles are added by translation, such as a, an, and the in English, the disclosure may include that the nouns following these articles are in the plural form.

[0358] Although the invention according to the present disclosure has been described in detail above, it is clear to those skilled in the art that the invention according to the present disclosure is not limited to the embodiments described in the present disclosure. The invention according to the present disclosure can be implemented in modified and altered forms without departing from the spirit and scope of the invention as defined by the description of the claims. Therefore, the description of the present disclosure is intended to be illustrative and explanatory and does not impose any limiting meaning on the invention according to the present disclosure.

Claims

1. a receiving unit for receiving at least one of information regarding a time domain resource indicated by a channel state information reference signal in a time unit longer than a slot, and information regarding a frequency domain resource supporting a frequency domain density of at least less than 0.5 by the channel state information reference signal; A terminal having a control unit that measures the channel state information reference signal based on at least one of information regarding the time domain resource and information regarding the frequency domain resource, performs machine learning on the results of the measurement, and estimates a channel using the machine learning interpolation.

2. The terminal according to claim 1 , wherein the information about the time domain resource includes information about an offset indicated in a time unit longer than a slot.

3. The terminal according to claim 1 or 2, wherein the information about the frequency domain resources includes information about one or more resource blocks to which the channel state information reference signal is allocated among a plurality of resource blocks.

4. The terminal according to claim 3 , wherein the information about the one or more resource blocks to which the channel state information reference signals are allocated is indicated in a bitmap format.

5. receiving at least one of information regarding time domain resources for a channel state information reference signal indicated in time units longer than a slot, and information regarding frequency domain resources for the channel state information reference signal supporting a frequency domain density at least less than 0.5; measuring the channel state information reference signal based on at least one of information about the time domain resource and information about the frequency domain resource; A wireless communication method for a terminal, comprising a step of machine learning the results of the measurement and estimating a channel using the completion obtained by the machine learning.

6. A system comprising a base station and a terminal, The base station a transmitter for transmitting at least one of information on a time domain resource indicated by a time unit longer than a slot for a channel state information reference signal and information on a frequency domain resource supporting a frequency domain density at least smaller than 0.5 for the channel state information reference signal; The terminal a receiver for receiving at least one of information about the time domain resource and information about the frequency domain resource; A control unit that measures the channel state information reference signal based on at least one of information about the time domain resource and information about the frequency domain resource, performs machine learning on the results of the measurement, and performs channel estimation using the machine learning interpolation.

Images