Terminal, wireless communication method, and base station

Abstract

To enable the use of appropriate reference signal resources. [Solution] The terminal of the present invention includes a receiving unit that receives information regarding the start symbol of a channel state information reference signal, The system includes a control unit that controls the reception of the channel state information reference signal, in which a frequency domain resource is set separately for each start symbol if multiple start symbols are included in the slot.

Description

[Technical Field]

[0001] This disclosure relates to terminals, wireless communication methods, and base stations in next-generation mobile communication systems. [Background technology]

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

[0003] Successor systems to LTE (for example, 5th generation mobile communication system (5G), 5G+ (plus), 6th generation mobile communication system (6G), New Radio (NR), 3GPP Rel.15 and later, etc.) are also 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 [Overview of the Initiative] [Problems that the invention aims to solve]

[0005] 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. For example, reducing reference signal (RS) resources using AI / ML augmentation is being explored.

[0006] However, the specific details of this RS resource reduction have not yet been considered. If these are not properly defined, highly efficient resource utilization may not be achieved, and improvements in communication throughput or communication quality may be suppressed.

[0007] Therefore, one of the objectives of this disclosure is to provide a terminal, a wireless communication method, and a base station that can enable the use of suitable RS resources. [Means for solving the problem]

[0008] A terminal according to one aspect of this disclosure includes a receiving unit that receives information regarding the start symbol of a channel state information reference signal, The system includes a control unit that controls the reception of the channel state information reference signal, in which a frequency domain resource is set separately for each start symbol if multiple start symbols are included in the slot. [Effects of the Invention]

[0009] According to one aspect of this disclosure, suitable RS resource utilization can be achieved. [Brief explanation of the drawing]

[0010] [Figure 1] Figure 1 shows an example of a resource mapping pattern for CSI-RS. [Figure 2]FIG. 2 is a diagram showing an example of upper layer parameters related to CSI-RS resource mapping information. [Figure 3] FIG. 3 is a diagram showing an example of the CSI-RS positions within a slot and an RB. [Figure 4] FIGS. 4A and 4B are diagrams showing an example of CSI-RS resource mapping for a specific CSI-RS position configuration (e.g., row). [Figure 5] FIG. 5 is a diagram showing another example of CSI-RS resource mapping for a specific CSI-RS position configuration (e.g., row). [Figure 6] FIGS. 6A-6C are diagrams showing an example of CSI-RS resource mapping according to Aspect 2-1 of the second embodiment. [Figure 7] FIG. 7 is a diagram showing an example of a method for indicating the RB position of the CSI-RS resource according to Aspect 2-1 of the second embodiment. [Figure 8] FIGS. 8A-8C are diagrams showing an example of CSI-RS resource mapping according to Aspect 2-2 of the second embodiment. [Figure 9] FIGS. 9A and 9B are diagrams showing another example of CSI-RS resource mapping according to Aspect 2-2 of the second embodiment. [Figure 10] FIGS. 10A and 10B are diagrams showing another example of CSI-RS resource mapping according to Aspect 2-2 of the second embodiment. [Figure 11] FIGS. 11A and 11B are diagrams showing 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 (e.g., row) of a specific CSI-RS position according to Aspect 2-2 of the second embodiment. [Figure 13] FIG. 13 is a diagram showing another example of CSI-RS resource mapping according to Aspect 2-2 of the second embodiment. [Figure 14]Figures 14A and 14B are diagrams showing an example of CSI-RS resource mapping according to the combination of Mode 2-1 and Mode 2-2 of the second embodiment. [Figure 15] Figures 15A and 15B are diagrams showing another example of CSI-RS resource mapping according to the combination of Mode 2-1 and Mode 2-2 of the second embodiment. [Figure 16] Figures 16A and 16B are diagrams showing an example of CSI-RS resource mapping according to Mode 2-3 of the second embodiment. [Figure 17] Figure 17 is a diagram showing an example of upper layer parameters related to CSI-RS resource mapping information according to Mode 2-3 of the second embodiment. <0​​​​​​​​​​​​​​​​​​​​​​​​​​​ [Modes for carrying out the invention]

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

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

[0013] Multiple-port CSI-RS is used, for example, to orthogonalize 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 and each UE within a single UE.

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

[0015] <Time Domain of CSI-RS> For periodic / semi-persistent CSI-RS, a predetermined periodicity (e.g., Periodicity) is set. Prior to Rel.16 NR, the predetermined periodicity is set in slot units, specifically, any of 4 / 5 / 8 / 10 / 16 / 20 / 32 / 40 / 64 / 80 / 160 / 320 / 640 slots is 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 OFDM symbol allocation (e.g., OFDM symbol allocation) by supporting one or two starting symbols in a single slot, and supports the allocation of one, two, or four adjacent symbols from each starting symbol.

[0019] CSI-RS frequency domain allocation may be performed by bitmap indication. For example, the location of a CSI-RS frequency domain (e.g., frequency-domain location) may be determined based on a bitmap provided by a higher-layer parameter for the CSI-RS resource (e.g., frequencyDomainAllocation) and a predetermined value (e.g., ki). frequencyDomainAllocation may be included in a higher-layer parameter for CSI-RS resource mapping (e.g., CSI-RS-ResourceMapping IE (see Figure 2) or CSI-RS-ResourceConfigMobility IE).

[0020] A predetermined value (e.g., ki) relating to the frequency position of a CSI-RS (e.g., CDM group) within a slot may be a value defined in a table relating to CSI-RS positions (see Figure 3).

[0021] Figure 3 shows an example of CSI-RS location within a slot. Each row in the table shows the row number, port number, frequency domain density, CDM type, time and frequency (time / frequency) location (component resource (CDM group) location (k-bar, l-bar)), 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 CSI-RS time and frequency resource (component resource) corresponding to one port. The k-bar is a notation with an overline on the "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 table showing the CSI-RS location in Figure 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) represents the number of the i-th bit in a bitmap set to 1 (e.g., frequencyDomainAllocation), and is repeated for every 1 / ρ ceiling function (e.g., ceil(1 / ρ)) in the resource block configured for CSI-RS reception by the UE.

[0023] For example, Figure 4A shows an example of a CSI-RS location corresponding to row #1. Here, we show the case with 1 port, a density of 3, and no CDM.

[0024] Figure 4B shows an example of the CSI-RS location corresponding to row #4. Here, we show the case with 4 ports, a density of 1, and fd-CDM2. In the frequency and time domains of a 1PRB × 1 slot, 2 × 1 component resources are mapped by multiplexing (FDM) twice in the frequency domain and once in the time domain. Furthermore, two CSI-RS are multiplexed (CDM) by multiplying the CSI-RS in each component resource by an FD-OCC of length 2 subcarriers. The CSI-RS contains two CDM groups; for example, the first CDM group (CDM group #0) contains two ports (e.g., port 3000, port 3001), and the second CDM group (CDM group #1) contains two ports (e.g., port 3002, port 3003).

[0025] Figure 5 shows an example of the CSI-RS location corresponding to row #17. Here, we show the case with 32 ports, a density of 1 (or 0.5), and cdm4-FD2-TD2. In the frequency and time domains of a 1PRB × 1 slot, 4 × 2 component resources are mapped by multiplexing 4 times in the frequency domain (FDM) and 2 times in the time domain (TDM). Furthermore, the CSI-RS in each component resource is multiplied by a 2-subcarrier FD-OCC and a 2-symbol TD-OCC to multiplex 4 CSI-RSs (CDM). The CSI-RS contains 8 CDM groups, and each CDM group contains 4 ports.

[0026] (Application of Artificial Intelligence (AI) technology to wireless communication) 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 beam-based communications, there is a need for higher accuracy in channel estimation (which may also be called channel measurement) for beam management, received signal decoding, and other purposes.

[0028] Channel estimation may be performed using at least one of the following: a channel status information reference signal (CSI-RS), a synchronization signal (SS), a synchronization signal / physical broadcast channel (SS / PBCH) block, a demodulation reference signal (DMRS), or a sounding reference signal (SRS).

[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-based interpolation is being explored to reduce the resources required for the reference signal (RS) while maintaining channel estimation accuracy.

[0031] For example, if AI / ML-based learning has not been performed (or completed) at a terminal (also called a user terminal or User Equipment (UE)) / base station, the following requirements may be necessary to achieve RS reception measurements that enable high channel estimation accuracy, or accurate RS reception measurements for use in learning: • Transmitting and receiving RS over a wide bandwidth (contributes to improved reception quality), • The receiving end repeatedly transmits RS in order to combine (combined reception) the received channels / signals (contributes to improving reception quality). • High time / frequency density of RS resources (contributes to obtaining appropriate time / frequency correlation).

[0032] Considering these factors, it is likely that the appropriate allocation of resource speeds (RS) will differ depending on whether the AI / ML training has been sufficiently performed or not. Therefore, it is desirable to introduce a framework for dynamically allocating appropriate RS resources.

[0033] However, the specific details of this framework have not yet been considered. If these are not properly defined, it may not be possible to achieve highly efficient resource utilization, and improvements in communication throughput or communication quality may be hindered.

[0034] Furthermore, in existing specifications (Rel.16 and earlier), the mapping settings for reference signals (e.g., CSI-RS) are specified to be controlled based on a predetermined periodicity and a predetermined resource mapping.

[0035] As mentioned above, in order to achieve highly efficient resource utilization, it is desirable to reduce the overhead of reference signals (e.g., CSI-RS / CSI-RS resources) by configuring more flexible and dynamic reference signal mapping.

[0036] Therefore, the inventors considered suitable methods for allocating / using RS resources and conceived this embodiment.

[0037] Furthermore, each embodiment of this disclosure may be applied even when AI / ML / prediction is not used. In this case, it becomes possible to change the RS settings while reducing latency / overhead without RRC reconfiguration.

[0038] In one embodiment of this disclosure, the UE / BS trains an ML model in training mode and runs the ML model in test mode (also called test mode or testing mode). In test mode, the accuracy of the trained ML model may be validated.

[0039] In this disclosure, the UE / BS may input channel status information, reference signal measurements, etc., to the ML model and output high-precision channel status information / measurements / beam selection / position, future channel status information / wireless link quality, etc.

[0040] In this disclosure, AI may be interpreted as an object (also called a subject, object, data, function, program, etc.) having (implementing) at least one of the following characteristics: • Estimation based on observed or collected information • Selection based on observed or collected information. • Predictions based on observed or collected information.

[0041] In this disclosure, the object may be, for example, a device such as a terminal or base station. The object may also be a program included in the device.

[0042] Furthermore, in this disclosure, the ML model may be replaced with an object having (implementing) at least one of the following features: • By providing information (feeding), estimates are generated. By providing information, predict the estimated value. By providing information, we can discover features. • By providing information, the user can select an action.

[0043] Furthermore, in this disclosure, the ML model may be interpreted as at least one of the following: an AI model, predictive analytics, or a predictive analytics model. The ML model may also be derived using at least one of the following: regression analysis (e.g., linear regression, multiple regression, logistic regression), support vector machines, random forests, neural networks, or deep learning. In this disclosure, the model may be interpreted as at least one of the following: an encoder, decoder, or tool.

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

[0045] The embodiments of this disclosure will be described in detail below with reference to the drawings. Each wireless communication method according to the embodiments may be applied individually or in combination.

[0046] In the following embodiments, the relevant entities are the UE and BS to illustrate an ML model relating to communication between UEs and BSs, but the application of each embodiment of this disclosure is not limited thereto. For example, for communication between other entities (e.g., UE-UE communication), the UE and BS in the embodiments below may be replaced with a first UE and a second UE. In other words, any UE, BS, etc. in this disclosure may be replaced with any UE / BS.

[0047] In this disclosure, "A / B" and "at least one of A and B" may be interpreted as mutually exclusive, and "A / B / C" and "at least one of A, B, and C" may be interpreted as mutually exclusive.

[0048] In this disclosure, activate, deactivate, indicate, select, configure, update, determine, etc., may be interpreted interchangeably. In this disclosure, support, control, controllable, operate, and operable may be interpreted interchangeably.

[0049] In this disclosure, Radio Resource Control (RRC), RRC parameters, RRC messages, upper layer parameters, information elements (IE), and settings may be interpreted interchangeably. In this disclosure, Medium Access Control elements (MAC Control Element (CE)), update commands, and activation / deactivation commands may be interpreted interchangeably.

[0050] In this disclosure, the following terms are used: panel, UE panel, panel group, beam, beam group, precoder, Uplink (UL) transmit entity, TRP, spatial relation information (SRI), spatial relation, SRS resource identifier (SRI), SRS resource, control resource set (CONTRO 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 relation group, and downlink Transmission Configuration Indication state (TCI state) (DL Terms such as TCI state, uplink TCI state (UL TCI state), unified TCI state, common TCI state, quasi-co-location (QCL), and QCL assumption may be interchangeable.

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

[0052] In this disclosure, "beam report" may be interpreted as "beam measurement report," "CSI report," "CSI measurement report," "predictive beam report," "predictive CSI report," etc.

[0053] In this disclosure, CSI-RS may be interpreted 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 mean the RS measured / reported for the purpose of the beam report.

[0055] In this disclosure, timing, time, duration, slot, sub-slot, symbol, subframe, etc., may be interpreted interchangeably.

[0056] In this disclosure, terms such as direction, axis, dimension, polarization, and polarization component may be interpreted interchangeably.

[0057] In this disclosure, estimation, prediction, and inference may be interpreted interchangeably. Also, in this disclosure, estimate, predict, and infer may be interpreted interchangeably.

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

[0059] In this disclosure, terms such as CSI feedback, CSI feedback information, CSI report, CSI report, CSI transmission, CSI information, and CSI may be interpreted interchangeably.

[0060] Furthermore, in this disclosure, the terms "subband" may be interpreted interchangeably with "physical resource block (PRB)," "subcarrier," "any frequency resource unit," etc.

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

[0062] In this disclosure, the terms "assigned," "mapped," "transmitted," and "received" of a reference signal may be interpreted interchangeably.

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

[0064] The periodicity of CSI-RS resources may be set to a value greater than the maximum periodicity in existing systems (e.g., Rel. 16 or earlier). For example, the periodicity of CSI-RS resources may be set 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 the existing system, it is possible to reduce the overhead of CSI-RS resources.

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

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

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

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

[0070] <Second Embodiment> In the second embodiment, the setting of frequency domains for CSI-RS resources 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>> It may be supported to set / apply a value different from the existing system value (e.g., 3, 1, 0.5) for the frequency domain density of CSI-RS resources. The newly set / applied frequency domain density value may be applied to each row of the CSI-RS resource location shown in Figure 3, or it may be applied selectively to some rows.

[0072] Alternatively, the newly set / applied frequency domain density values ​​may be applied to a new row different from the row (e.g., row #1 to row #18) indicating the CSI-RS resource locations shown in Figure 3. In this disclosure, "row" may be interpreted as a configuration of CSI-RS locations (e.g., CSI-RS locations within a slot) or a candidate CSI-RS location.

[0073] As a new frequency domain density (e.g., ρ_new) that differs from the frequency domain density of the existing system (e.g., 3, 1, 0.5), at least one of the following options 2-1-1 to 2-1-2 may be applied.

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

[0075] If the new frequency domain density (e.g., ρ_new) is 1 / N, it may mean that the CSI-RS resource mapping pattern (e.g., row) is repeated only once for 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, we show the case with 1 port, a density of 1 / 4 (N=4, ρ_new=1 / 4), and no CDM. In other words, the CSI-RS resource mapping pattern (in this case, row #2) is repeated only once for every 4 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 may be 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 becomes 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 every N (= 1 / ρ_new) resource blocks (e.g., RBs). The M RBs may be consecutive RBs or non-consecutive RBs.

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

[0082] If the new frequency domain densities shown in Option 2-1-1 / Option 2-1-2 are supported, the RB positions occupied by the CSI-RS (e.g., occupied RB position(s)) may be defined in the specification or indicated to the UE from the network. The RB positions occupied by the CSI-RS may be interpreted as the RB positions where the CSI-RS is located / mapped to / assigned to.

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

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

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

[0086] If the starting RB position is not specified / set, the default starting position may be applied. The default starting position 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 the table used for CSI-RS resource mapping positions, or it may be included in the higher-layer parameters related to CSI-RS resource mapping.

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

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

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

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

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

[0093] <<Aspect 2-2>> If the frequency domain density of the CSI-RS resources 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, if the density of frequency domains is less than 1, the configuration of CSI-RS locations within a slot may be applied across multiple RBs (or different RBs). The configuration of CSI-RS locations within a slot may be, for example, at least one of rows #1 to #18 (or a newly defined / configured row) included in the table shown in Figure 3.

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

[0096] In Figure 8B, in the frequency and time domains of a 1PRB × 1 slot, 3 × 2 component resources of 2 subcarriers × 2 symbols are multiplexed three times in the frequency domain (FDM) and two times in the time domain (TDM), resulting in the mapping of 3 × 2 component resources. Furthermore, the CSI-RS of each component resource is multiplied by a 2-subcarrier FD-OCC and a 2-symbol TD-OCC, resulting in 4 CSI-RS multiplexed (CDM). The CSI-RS contains 6 CDM groups, and each CDM group contains 4 ports.

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

[0098] In Figure 8C, in a 2PRB × 1 slot, 3 × 2 component resources are mapped by multiplexing 3 times in the frequency domain (FDM) and 2 times in the time domain (TDM) of 2 subcarrier × 2 symbol component resources in the frequency domain and time domain. Furthermore, 4 CSI-RS are multiplexed (CDM) by multiplying the CSI-RS of each component resource by a 2-subcarrier FD-OCC and a 2-symbol TD-OCC. The CSI-RS contains 6 CDM groups, each containing 4 ports. Here, we show the case where 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 given row) to multiple RBs, it becomes possible to improve the flexibility of CSI-RS mapping and achieve frequency domain diversity. Furthermore, it becomes possible to reduce the frequency domain density in a single slot. Moreover, by applying this in combination with embodiment 2-1, it becomes possible to effectively reduce the frequency domain density.

[0100] When the frequency domain density is less than 1, and different ports / different CDM groups are mapped to multiple RBs, the range of k-bar / ki values ​​in the CSI-RS location configuration (e.g., CSI-RS resource mapping table) may be expanded / modified. In this case, the bitmap length (or size) set / notified by the higher-layer parameter (e.g., FrequencyDomainAllocation) for frequency domain allocation may be expanded. The higher-layer parameter (e.g., frequencyDomainAllocation) may indicate the occupation of frequency domain resources across multiple RBs (e.g., frequency domain resource occupation).

[0101] The bitmap length set / notified by the upper layer parameters may be changeable (or variable) based on predetermined conditions (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 expanded by a factor of two. The range of k-bar / ki values ​​may also be expanded (e.g., [0,22] (for FD2), [0,23] (for fd-CDM2)).

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

[0103] If the bitmap lengths of rows other than row#1, row#2, and row#4 are extended, the following relationships may be defined in each row of the table relating 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) indicates the number of the i-th bit of the bitmap set to 1, and is repeated for every two consecutive RBs (for example, when the density in the frequency domain is 0.5).

[0104] Also, the upper layer parameters (for example, {evenPRBs, oddPRBs}) regarding the RBs indicated for the frequency domain density of 0.5 may indicate the RBs to which a specific CDM group (for example, CDM group 0) is mapped.

[0105] FIG. 9A shows an example of the pattern of CSI-RS resource mapping corresponding to row#14. The network (for example, the base station) may indicate to the UE a bitmap with an extended size as an upper layer parameter regarding 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 the row corresponding to CSI-RS (here, row#14) based on the upper layer parameter including the bitmap notified from the base station, and then determines the frequency domain position of CSI-RS. The UE may determine the row based on the port / density / CDM type notified by the upper layer parameter, or information specifying the row may be notified to the UE by the upper layer parameter.

[0107] When the density in the frequency domain is 0.5 for row#14, the UE is [b11……b0], k i-1Based on =2f(i) and the bitmap (100000001010), the frequency domain positions of the CSI-RS (each component resource) are determined to be k0=2, k1=6, and k2=22 (see Figure 9B).

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

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

[0110] Figure 10A shows an example of a CSI-RS resource mapping pattern corresponding to the new row#x. Here, we show the case with 48 ports, a density of 0.5, and cdm4-FD2-TD2. We also show the case where the frequency domains are k0, k1, k2, k3, k4, and k5.

[0111] A network (e.g., a base station) may instruct the UE to provide an expanded bitmap as a higher-layer parameter for CSI-RS frequency domain allocation (e.g., frequencyDomainAllocation). Here, we show a case where "101010101010" is instructed as the bitmap corresponding to row#x.

[0112] The UE selects the row corresponding to the CSI-RS (here, row#x) 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 in the higher-layer parameters, or the information specifying the row may be notified to the UE in the higher-layer parameters.

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

[0114] Figure 10B shows an example of a CSI-RS location corresponding to row#x. The CSI-RS resource is mapped to both (or across both) RBs. For example, different ports / CDM groups are mapped to the two RBs. Here, we show the 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 position of the CSI-RS frequency domain corresponding to CDM groups 0 and 6 is determined based on k0 (=2). Similarly, the position of the CSI-RS frequency domain corresponding to CDM groups 1 and 7 is determined based on k1 (=6), the position of the CSI-RS frequency domain corresponding to CDM groups 2 and 8 is determined based on k2 (=10), the position of the CSI-RS frequency domain corresponding to CDM groups 3 and 9 is determined based on k3 (=14), the position of the CSI-RS frequency domain corresponding to CDM groups 4 and 10 is determined based on k4 (=18), and the position of the CSI-RS frequency domain corresponding to CDM groups 5 and 11 is determined based on k5 (=22). Note that the reference point of ki in the frequency direction may be one of the multiple (in this case, two) RBs (for example, subcarrier 0 of the RB with the smaller index).

[0116] Figures 9A and 10A show the case where the bitmap length is extended, but it is also possible to use a configuration in which the bitmap length is not extended, and an offset is added to the k-bar (e.g., ki) defined / set in the configuration of the CSI-RS position (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 for CSI-RS locations, and the k-bar / ki range in the new row may be defined differently from that of the existing row. For example, 0 ≤ k-bar ≤ 12 / ρ-1 and 0 ≤ ki ≤ 11. The indicated resource mapping allocation (k-bar, l-bar) may be repeated in RBs of 1 / ρ. A higher-layer parameter for frequency domain allocation (e.g., frequencyDomainAllocation) may indicate the resource allocation location of a frequency domain in one RB.

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

[0119] A network (e.g., a base station) may instruct the UE to use an unexpanded bitmap as a higher-layer parameter for CSI-RS frequency domain allocation (e.g., frequencyDomainAllocation). Here, we show a case where "101010" is instructed as the bitmap corresponding to row#x.

[0120] The UE selects the row corresponding to the CSI-RS (here, row#x) 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 in the higher-layer parameters, or the information specifying the row may be notified to the UE in the higher-layer parameters.

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

[0122] Figure 11B shows an example of a CSI-RS location corresponding to row#x. The CSI-RS resource is mapped to both (or across both) RBs. For example, different ports / CDM groups are mapped to the two RBs. Here, we show the case where 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 CSI-RS frequency domain locations corresponding to CDM groups 0 and 3 are determined based on k0 (=2). The CSI-RS frequency domain locations corresponding to CDM groups 1 and 4 are determined based on k1 (=6) + 12. The CSI-RS frequency domain locations corresponding to CDM groups 2 and 5 are determined based on k2 (=10).

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

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

[0126] Figure 12 shows an example of a CSI-RS resource mapping pattern (or parameters) corresponding to row#x and row#y, respectively. Here, the case with 48 ports, a density of 0.5, and cdm4-FD2-TD2 is shown. It also shows the case where the frequency domains are represented as k0, k1, k2, k0+12, k1+12, and k2+12. Here, the values ​​of (k bars, l bars) corresponding to each CDM group are defined differently (or in a different order) in row#x and row#y.

[0127] A network (e.g., a base station) may instruct the UE to use an unexpanded bitmap as a higher-layer parameter for CSI-RS frequency domain allocation (e.g., frequencyDomainAllocation). Here, we show the case where "101010" is instructed as the bitmap corresponding to row#x / row#y.

[0128] The UE selects the row corresponding to the CSI-RS (here, row#x or row#y) 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 in the higher-layer parameters, or the information specifying the row may be notified to the UE in the higher-layer parameters.

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

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

[0131] Here, for row#x, we show the 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. The position of the frequency domain of the CSI-RS corresponding to CDM groups 0 and 6 is determined based on k0 (=2), the position of the frequency domain of the CSI-RS corresponding to CDM groups 1 and 7 is determined based on k1 (=6), and the position of the frequency domain of the CSI-RS corresponding to CDM groups 2 and 8 is determined based on k2 (=10). The position of the frequency domain of the CSI-RS corresponding to CDM groups 3 and 9 is determined based on k0 (=2) + 12, the position of the frequency domain of the CSI-RS corresponding to CDM groups 4 and 10 is determined based on k1 (=6) + 12, and the position of the frequency domain of the CSI-RS corresponding to CDM groups 5 and 11 is determined based on k2 (=10) + 12.

[0132] On the other hand, row#y shows the 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 positions of the frequency domains of the CSI-RS corresponding to CDM groups 0 and 3 are determined based on k0 (=2), the positions of the frequency domains of the CSI-RS corresponding to CDM groups 1 and 4 are determined based on k1 (=6), and the positions of the frequency domains of the CSI-RS corresponding to CDM groups 2 and 5 are determined based on k2 (=10). The positions of the frequency domains of the CSI-RS corresponding to CDM groups 6 and 9 are determined based on k0 (=2) + 12, the positions of the frequency domains of the CSI-RS corresponding to CDM groups 7 and 10 are determined based on k1 (=6) + 12, and the positions of the frequency domains of the CSI-RS corresponding to CDM groups 8 and 11 are determined based on k2 (=10) + 12.

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

[0134] In the above explanation, the case where the frequency domain density is less than 1 was shown as a case where the frequency domain density is 0.5, but the applicable frequency domain density is not limited to 0.5. Embodiment 2-2 may be applied to frequency domain densities other than 0.5 (for example, by combining Embodiment 2-1 and Embodiment 2-2).

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

[0136] The network (e.g., a base station) may instruct the UE to provide an expanded bitmap as a higher-layer parameter for CSI-RS frequency domain allocation (e.g., frequencyDomainAllocation).

[0137] The bitmap length set / notified by the higher-layer parameters may be changeable (or variable) based on predetermined conditions (e.g., frequency domain density of CSI-RS). For example, if the density ρ_new = 1 / N or ρ_new = M / N, the bitmap length (or size) notified by the higher-layer parameters (e.g., frequencyDomainAllocation) may be expanded by N times. Also, the range of the k-bar / ki value may be expanded (e.g., [0, N × 12 - 2]).

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

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

[0140] In embodiment 2-1, the indicated / defined occupied RB position(s) may indicate an RB position of a particular CDM group index (e.g., CDM group index 0). The occupied RB position may be indicated by upper-layer signaling or may be defined by usage on a per-row basis.

[0141] This example shows the case where the bitmap corresponding to row#x is specified as "000000,100000,001000,000010".

[0142] The UE selects the row corresponding to the CSI-RS (here, row#x) 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 in the higher-layer parameters, or the information specifying the row may be notified to the UE in the higher-layer parameters.

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

[0144] Figure 14B shows an example of a CSI-RS location corresponding to row #14. A CSI-RS resource can be mapped across four RBs (in this case, it is mapped to three RBs). For example, it is permissible for different ports / CDM groups to be mapped to each of the four RBs. Here, we show a case where 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 position of the frequency domain of the CSI-RS corresponding to CDM groups 0 and 3 is determined based on k0 (=2). Similarly, the position of the frequency domain of the CSI-RS corresponding to CDM groups 1 and 4 is determined based on k1 (=18), and the position of the frequency domain of the CSI-RS corresponding to CDM groups 2 and 5 is determined based on k2 (=32). Note that the reference point of ki in the frequency direction may be a specific RB (for example, subcarrier 0 of the RB with the smallest index) among several (in this case, four) RBs.

[0146] Figure 14A shows the case where the bitmap length is extended, but it is also possible to use 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) (see Figure 15A).

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

[0148] Figure 15A shows an example of a CSI-RS resource mapping pattern corresponding to a new row#x. Here, we show the case with 24 ports, a density of 1 / 4, and cdm4-FD2-TD2. We also show the case where the frequency domains are represented as k0, k1+12, and k2+24. In other words, an offset in the frequency direction is applied 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 value of the offset may be determined based on the CDM type, the number of ports, the frequency domain density, and at least one of the parameters set in the RRC.

[0150] A network (e.g., a base station) may instruct the UE to use an unexpanded bitmap as a higher-layer parameter (e.g., frequencyDomainAllocation) for CSI-RS frequency domain allocation. For example, a table of CSI-RS locations within a slot, including more than 12 frequency offsets as described above, may be added according to a predetermined rule, and the UE may decide 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 UE may decide which row to refer to based on the higher-layer parameter. Here, we show a case where "101010" is instructed as the bitmap corresponding to row#x.

[0151] The UE selects the row corresponding to the CSI-RS (here, row#x) 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 in the higher-layer parameters, or the information specifying the row may be notified to the UE in the higher-layer parameters.

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

[0153] Figure 15B shows an example of a CSI-RS location corresponding to row#x. A CSI-RS resource can be mapped across four RBs (in this case, it is mapped to three RBs). For example, it is permissible for different ports / CDM groups to 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 CSI-RS frequency domain positions corresponding to CDM groups 0 and 3 are determined based on k0 (=2). The CSI-RS frequency domain positions corresponding to CDM groups 1 and 4 are determined based on k1 (=6) + 12. The CSI-RS frequency domain positions corresponding to CDM groups 2 and 5 are determined based on k2 (=10) + 24.

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

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

[0157] By combining and applying embodiments 2-1 and 2-2 in this way, 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 (e.g., two) start symbols are set within a single slot, it may be supported to set / apply different frequency domain resource allocations to different start symbols.

[0159] Furthermore, embodiment 2-3 may be applied to configurations of CSI-RS locations in which multiple start symbols are set within a single slot (for example, rows #11, #13, #14, #17, or a new row in the table relating to the CSI-RS location).

[0160] If multiple start symbols are set within a single slot, it may be supported that the frequency domain resource allocation of the CSI-RS resource be set separately (e.g., differently) for each start symbol.

[0161] Figure 16A illustrates a case where multiple start symbols are set within a single slot, and the CSI-RS frequency domain resource allocation is set commonly for multiple start symbols (e.g., l0, l1). In Figure 16A, the frequency domain resource allocation for CDM groups 0-2 mapped to the first start symbol and the frequency domain resource allocation for CDM groups 3-5 mapped to the second start symbol are set 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 allocated to a common frequency domain resource.

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

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

[0164] For multiple (e.g., two) start symbols within a single slot, bitmaps corresponding to multiple (e.g., two) frequency domains may be set / indicated / applied. The bitmaps corresponding to multiple frequency domains may be set by higher-layer parameters (see Figure 17).

[0165] Figure 17 shows an example of higher-layer parameters for CSI-RS resource mapping (e.g., CSI-RS-ResourceMapping). A network (e.g., a base station) may use these higher-layer parameters to notify the UE of bitmaps for two frequency domains (e.g., frequencyDomainAllocation and frequencyDomainAllocation2).

[0166] The UE may apply multiple (e.g., two) notified frequency domain bitmaps to different start symbols. Note that Figure 17 shows the case where the size (or bitmap length) of the second bitmap is 6, but this is not limited to this, and 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 only exist if a specific CSI-RS location configuration (e.g., row) is set / indicated. The specific row may be a row in which multiple start symbols are set within a single slot (e.g., row#13 / #14 / #16 / #17). If the second bitmap is not included when a specific row is set, the UE may apply the same rules as the mapping pattern for CSI-RS resources in the existing system (Rel.15 / 16).

[0168] Figure 18A shows an example of a CSI-RS resource mapping pattern corresponding to row #14. Here, the cases with 24, 20, and 28 ports, densities of 1 and 0.5, and cdm4-FD2-TD2 are shown. It also shows the 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. Note that the number of ports to be configured may also be specified by upper-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 for frequency domain allocation in CSI-RS.

[0170] The UE selects the row corresponding to the CSI-RS (in this case, row #14) 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 in the higher-layer parameters, or the information specifying the row may be notified to the UE in the higher-layer parameters.

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

[0172] Figure 18B shows the case where there are 24 ports (6 CDM groups), and "101010" is notified as the first bitmap and "010101" 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, and k2=8.

[0173] Figure 18C shows the case where there are 20 ports (5 CDM groups), and the first bitmap is "101010" and the second bitmap is "000101". 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 and k1=4.

[0174] Figure 18D shows the case where there are 28 ports (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] Figures 18A-D show, but are not limited to, cases where multiple bitmaps are notified to the UE. Alternatively, the second bitmap (e.g., frequencyDomainAllocation2) may not be notified, and separate k-bars (e.g., ki) corresponding to different start symbols may be defined / set.

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

[0177] Figure 19A shows an example of a CSI-RS resource mapping pattern corresponding to a new row#x. Here, we show the case with 24 ports, densities of 1 and 0.5, and cdm4-FD2-TD2. We also show the case where the frequency domains corresponding to the first start symbol are defined as k0, k1, and k2, and the frequency domains corresponding to the second start symbol are defined as (k0+2)mod2, (k1+2)mod2, and (k2+2)mod2.

[0178] A network (e.g., a base station) may instruct the UE to use a bitmap as a higher-layer parameter for CSI-RS frequency domain allocation (e.g., frequencyDomainAllocation). Here, we show a case where "101010" is instructed as the bitmap corresponding to row#x.

[0179] The UE selects the row corresponding to the CSI-RS (here, row#x) 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 in the higher-layer parameters, or the information specifying the row may be notified to the UE in the higher-layer parameters.

[0180] For row#x, UE is [b5……b0],k i-1Based on =2f(i) and the bitmap (101010), it is determined that k0=2, k1=6, and k2=10, and the location of the frequency domain resources for CSI-RS (each component resource) is determined (see Figure 19B). Here, the locations of the frequency domain resources corresponding to the first start symbol (frequency domain resources corresponding to CDM groups 0, 1, and 2 respectively) are k0=2, k1=6, and k2=10, and the locations of the frequency domain resources corresponding to the second start symbol (frequency domain resources corresponding to CDM groups 3, 4, and 5 respectively) are (k0+2)mod12=4, (k1+2)mod12=8, and (k2+2)mod12=0.

[0181] Furthermore, Embodiment 2-3 may be applied in combination with at least one of Embodiments 2-1 and 2-2.

[0182] <<Aspect 2-2 + Aspect 2-3>> If the frequency domain density value of a CSI-RS resource is less than 1 and multiple (e.g., two) start symbols are configured within a single slot, then mapping different port / CDM groups to multiple RBs (or different RBs) may be supported, and different frequency domain resource assignments to different start symbols may be supported.

[0183] Figure 20A shows an example of a CSI-RS resource mapping pattern corresponding to row #14. Here, the case with 24 ports, densities of 1 and 0.5, and cdm4-FD2-TD2 is shown. It also shows the case where the frequency domains corresponding to the first start symbol (e.g., l0) and the second start symbol (e.g., l1) are represented by k0, k1, and k2. Note that the density of the frequency domains to be set may also 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 for frequency domain allocation in CSI-RS.

[0185] The UE selects the row corresponding to the CSI-RS (in this case, row #14) 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 in the higher-layer parameters, or the information specifying the row may be notified to the UE in the higher-layer parameters.

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

[0187] Figure 20B shows the case where there are 24 ports (6 CDM groups), and the first bitmap is "000000101010" and the second bitmap is "010101000000". 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] This example shows the case 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] Thus, different starting symbols support bitmap instructions with different frequency domain assignments, and when the frequency domain density is less than 1, it becomes possible to map multiple ports with different frequency domain resource assignments to different RBs.

[0190] Figures 20A and 20B show, but are not limited to, cases where multiple bitmaps are notified to the UE. Alternatively, the second bitmap (e.g., frequencyDomainAllocation2) may not be notified, and k-bars (e.g., ki) corresponding to different start symbols may be defined / set separately.

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

[0192] Figure 21A shows an example of a CSI-RS resource mapping pattern corresponding to row #14. Here, the cases with 24 ports, densities of 1, 0.5, 1 / 4, and cdm4-FD2-TD2 are shown. It also shows the 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. Note that the density of the frequency domains to be set may also 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 for frequency domain allocation in CSI-RS.

[0194] The UE selects the row corresponding to the CSI-RS (in this case, row #14) 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 in the higher-layer parameters, or the information specifying the row may be notified to the UE in the higher-layer parameters.

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

[0196] Figure 21B shows the case where there are 24 ports (6 CDM groups), and the first bitmap is notified as "000000,100000,001000,000010", and the second bitmap is notified as "100000,000001,000000,100000". 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=18, and k2=34. 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=10, k1=24, and 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, the frequency domain resources for CDM groups 0, 1, and 2 corresponding to the first start symbol and the frequency domain resources for CDM groups 3, 4, and 5 corresponding to the second start symbol are configured separately.

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

[0199] Figures 21A and 21B show, but are not limited to, cases where multiple bitmaps are notified to the UE. Alternatively, the second bitmap (e.g., frequencyDomainAllocation2) may not be notified, and k-bars (e.g., ki) corresponding to different start symbols may be defined / set separately.

[0200] Which of embodiments 2-1 to 2-3 applies may be set in the UE by higher-layer parameters, reported by the UE as UE capability information, or defined by the specification. Alternatively, which of embodiments 2-1 to 2-3 applies may be determined by considering the UE capability information reported by the UE and the higher-layer parameters set in the UE.

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

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

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

[0204] UE capability information may be defined regarding whether or not a predetermined value (for example, a new value not supported by 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 described above may be configurations applied to a UE that supports / reports at least one of the UE capabilities described above. Alternatively, the embodiments may be configurations applied to a UE configured from a network.

[0207] (Wireless communication system) The configuration of a wireless communication system according to one embodiment of this disclosure will be described below. In this wireless communication system, communication is performed using any or a combination thereof of the wireless communication methods according to the above embodiments of this disclosure.

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

[0209] Furthermore, the wireless communication system 1 may 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)), and so on.

[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 where both MN and SN are NR base stations (gNB) (NR-NR Dual Connectivity (NN-DC))).

[0212] The wireless communication system 1 may include a base station 11 that forms a macrocell C1 with relatively wide coverage, and base stations 12 (12a-12c) located within the macrocell C1 that form a small cell C2 that is narrower than the macrocell C1. User terminals 20 may be located within at least one cell. The arrangement and number of each cell and user terminal 20 are not limited to the configuration shown in the figure. Hereinafter, when base stations 11 and 12 are not distinguished, 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 the first frequency band (Frequency Range 1 (FR1)) and the second frequency band (Frequency Range 2 (FR2)). A macrocell C1 may be included in FR1, and a 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 fall in a frequency band higher than FR2.

[0215] Furthermore, the user terminal 20 may communicate using at least one of the following methods at each CC: Time Division Duplex (TDD) and Frequency Division Duplex (FDD).

[0216] Multiple base stations 10 may be connected by wire (e.g., optical fiber compliant with Common Public Radio Interface (CPRI), X2 interface, etc.) or wireless (e.g., NR communication). For example, if NR communication is used as a backhaul between base stations 11 and 12, base station 11, which is the upstream station, may be called an Integrated Access Backhaul (IAB) donor, and base station 12, which is the relay station, may be called an IAB node.

[0217] Base station 10 may be connected to the core network 30 via other base stations 10 or directly. The core network 30 may include at least one of the following: Evolved Packet Core (EPC), 5G Core Network (5GCN), Next Generation Core (NGC), etc.

[0218] The user terminal 20 may be a terminal that supports at least one of the following communication methods: LTE, LTE-A, 5G, etc.

[0219] In the wireless communication system 1, an orthogonal frequency division multiplexing (OFDM)-based wireless access scheme may be used. 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), etc., may be used in at least one of the downlink (DL) and uplink (UL).

[0220] The wireless access method may also be called a waveform. In wireless communication system 1, other wireless access methods (for example, other single-carrier transmission methods, other multi-carrier transmission methods) may be used for the UL and DL wireless access methods.

[0221] In the wireless communication system 1, a Physical Downlink Shared Channel (PDSCH), a Broadcast Channel (PBCH), or a Physical Downlink Control Channel (PDCCH) may be used as the downlink channel, shared by each user terminal 20.

[0222] Furthermore, in the wireless communication system 1, the uplink channel may include a Physical Uplink Shared Channel (PUSCH), a Physical Uplink Control Channel (PUCCH), a Physical Random Access Channel (PRACH), or the like, all of which are shared by each user terminal 20.

[0223] User data, higher-layer control information, and System Information Blocks (SIBs) are transmitted via PDSCH. User data and higher-layer control information may also be transmitted via PUSCH. Furthermore, Master Information Blocks (MIBs) may be transmitted via PBCH.

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

[0225] Furthermore, the DCI that schedules PDSCH may be called a DL assignment or DL ​​DCI, and the DCI that schedules PUSCH may be called a UL grant or UL DCI. Furthermore, PDSCH may be interpreted as DL data, and PUSCH may be interpreted as UL data.

[0226] PDCCH detection may utilize a Control Resource Set (CORESET) and a search space. A CORESET corresponds to the resources used to search for DCIs. A search space corresponds to the search area and search method for PDCCH candidates. A single CORESET may be associated with one or more search spaces. The UE may monitor CORESETs associated with a particular search space based on the search space configuration.

[0227] A single search space may correspond to one or more PDCCH candidates corresponding to aggregation levels. One or more search spaces may be referred to as a search space set. In this disclosure, "search space," "search space set," "search space configuration," "search space set configuration," "CORESET," and "CORESET configuration" may be interpreted interchangeably.

[0228] PUCCH may transmit uplink control information (UCI) which includes at least one of the following: channel state information (CSI), delivery acknowledgment (e.g., Hybrid Automatic Repeat reQuest ACKnowledgement (HARQ-ACK), ACK / NACK, etc.), and scheduling request (SR). PRACH may transmit a random access preamble for establishing a connection with the cell.

[0229] In this disclosure, downlinks, uplinks, etc., may be expressed without the prefix "link." Also, the prefix "physical" may be omitted from the names of various channels.

[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, as DL-RS, a cell-specific reference signal (CRS), a channel state information reference signal (CSI-RS), a demodulation reference signal (DMRS), a positioning reference signal (PRS), a phase tracking reference signal (PTRS), etc., may be transmitted.

[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 SS (PSS, SSS) and PBCH (and DMRS for PBCH) may be called an SS / PBCH block, SS Block (SSB), etc. SS, SSB, etc., may also be called reference signals.

[0232] Furthermore, in the wireless communication system 1, the Uplink Reference Signal (UL-RS) may transmit the Sounding Reference Signal (SRS), Demodulation Reference Signal (DMRS), etc. The DMRS may also be called the User-Specific Reference Signal (UE-specific Reference Signal).

[0233] (base station) Figure 23 shows an example of the configuration of a base station according to one embodiment. The base station 10 includes a control unit 110, a transceiver unit 120, a transceiver antenna 130, and a transmission line interface 140. Note that one or more of the control unit 110, transceiver unit 120, transceiver antenna 130, and transmission line interface 140 may be provided.

[0234] In this example, the functional blocks of the characteristic parts of this 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 part described below may be omitted.

[0235] The control unit 110 controls the entire base station 10. The control unit 110 can consist of a controller, control circuit, etc., as described based on common understanding in the art relating to this disclosure.

[0236] The control unit 110 may control signal generation, scheduling (e.g., resource allocation, mapping), etc. The control unit 110 may also control transmission and reception, measurement, etc., using the transceiver unit 120, the transceiver antenna 130, and the transmission path interface 140. 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 also perform call processing of communication channels (setting, releasing, etc.), status management of the base station 10, management of radio resources, etc.

[0237] The transmitting / receiving 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 transmitting / receiving unit 120 can be composed of a transmitter / receiver, RF circuit, baseband circuit, filter, phase shifter, measurement circuit, transmitting / receiving circuit, etc., as described based on common understanding in the art relating to this disclosure.

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

[0239] The transmitting and receiving antenna 130 can be composed of an antenna described based on common understanding in the art relating to this disclosure, such as an array antenna.

[0240] The transmitting / receiving unit 120 may transmit the downlink channel, synchronization signal, downlink reference signal, etc. The transmitting / receiving unit 120 may also receive the uplink channel, uplink reference signal, etc.

[0241] The transmitting / receiving unit 120 may form at least one of the transmitting beam and the receiving beam using digital beamforming (e.g., precoding), analog beamforming (e.g., phase rotation), or the like.

[0242] The transmitting / receiving unit 120 (transmission processing unit 1211) may perform processing on data and control information acquired from the control unit 110, for example, at the Packet Data Convergence Protocol (PDCP) layer, the Radio Link Control (RLC) layer (e.g., RLC retransmission control), the Medium Access Control (MAC) layer (e.g., HARQ retransmission control), etc., to generate a bit sequence to be transmitted.

[0243] The transmitting / receiving unit 120 (transmission processing unit 1211) may perform transmission processing on the bit sequence to be transmitted, 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, and output a baseband signal.

[0244] The transmitting / receiving unit 120 (RF unit 122) may perform modulation, filtering, amplification, etc., of the baseband signal to the radio frequency band and transmit the signal in the radio frequency band via the transmitting / receiving antenna 130.

[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 130.

[0246] The transmitting / receiving unit 120 (receiving processing unit 1212) may apply reception processing to the acquired baseband signal, such as analog-to-digital conversion, Fast Fourier Transform (FFT) processing, Inverse Discrete Fourier Transform (IDFT) processing (if necessary), filtering, demapping, demodulation, decoding (may include error correction decoding), MAC layer processing, RLC layer processing, and PDCP layer processing, to acquire user data, etc.

[0247] The transmitting / receiving unit 120 (measurement unit 123) may perform measurements related to 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 also measure received power (e.g., Reference Signal Received Power (RSRP)), reception 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 send and receive signals (backhaul signaling) with 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] In this disclosure, the transmitting and receiving units of the base station 10 may consist of at least one of a transmitting / receiving unit 120, a transmitting / receiving antenna 130, and a transmission path interface 140.

[0250] The transmitting / receiving unit 120 may transmit, in response to the channel state information reference signal, at least one of the following: information about time domain resources indicated in time units longer than the slot, and information about frequency domain resources that support a frequency domain density of at least 0.5. The control unit 110 may control the mapping of the channel state information reference signal to at least one of the information about time domain resources and information about frequency domain resources.

[0251] Alternatively, the transceiver unit 120 may transmit information regarding the frequency domain density of the channel state information reference signal. When the frequency domain density is less than 1, the control unit 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 a plurality of resource blocks.

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

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

[0254] In this example, the functional blocks of the characteristic parts in the present embodiment are mainly shown, and the user equipment 20 may be assumed to have other functional blocks necessary for wireless communication. A part of the processing of each unit described below may be omitted.

[0255] The control unit 210 controls the entire user equipment 20. The control unit 210 may be composed of a controller, a control circuit, etc., which are described based on the common knowledge in the technical field related to the present disclosure.

[0256] The control unit 210 may control signal generation, mapping, etc. The control unit 210 may control transmission, 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 composed of a transmitter / receiver, an RF circuit, a baseband circuit, a filter, a phase shifter, a measurement circuit, a transceiver circuit, etc., which are described based on the common knowledge in the technical field related to this disclosure.

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

[0259] The transceiver antenna 230 may be composed of an antenna, such as an array antenna, etc., which is described based on the common knowledge in the technical field related to this disclosure.

[0260] The transceiver unit 220 may receive the above-mentioned downlink channel, synchronization signal, downlink reference signal, etc. The transceiver unit 220 may transmit the above-mentioned uplink channel, uplink reference signal, etc.

[0261] The transceiver unit 220 may form at least one of a transmission beam and a reception beam by using digital beamforming (e.g., precoding), analog beamforming (e.g., phase rotation), etc.

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

[0263] The transmitting / receiving unit 220 (transmission processing unit 2211) may perform transmission processing on the bit sequence to be transmitted, 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, and output a baseband signal.

[0264] Whether or not to apply DFT processing may be based on the transform precoding settings. The transmitting / receiving unit 220 (transmission processing unit 2211) may perform DFT processing as part of the transmission process to transmit a channel (for example, PUSCH) using a DFT-s-OFDM waveform if transform precoding is enabled for that channel, or it may not perform DFT processing as part of the transmission process if transform precoding is not enabled for that channel.

[0265] The transmitting / receiving unit 220 (RF unit 222) may perform modulation, filtering, amplification, etc., of the baseband signal to the radio frequency band and transmit the signal in the radio frequency band 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 transmitting / receiving unit 220 (receiving processing unit 2212) may apply reception processing such as analog-to-digital conversion, FFT processing, IDFT processing (if necessary), filtering, demapping, demodulation, decoding (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 transmitting / receiving unit 220 (measuring unit 223) may perform measurements related to the received signal. For example, the measuring unit 223 may perform RRM measurement, CSI measurement, etc., based on the received signal. The measuring unit 223 may also 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] In this disclosure, the transmitting and receiving units of the user terminal 20 may consist of at least one of a transmitting / receiving unit 220 and a transmitting / receiving antenna 230.

[0270] The transmitting / receiving unit 220 may receive at least one of the following in response to the channel state information reference signal: information about time domain resources indicated in time units longer than the slot, and information about frequency domain resources that support a frequency domain density of at least 0.5. The control unit 210 may control the reception of the channel state information reference signal based on at least one of the information about time domain resources and the information about frequency domain resources (Aspect 2-1 of the first / second embodiment).

[0271] Information regarding time-domain resources may include information regarding offsets indicated in time units longer than the slot. Information regarding frequency-domain resources may include information regarding one or more resource blocks to which the channel state information reference signal is assigned in multiple resource blocks. The information regarding one or more resource blocks to which the channel state information reference signal is assigned may be indicated in bitmap format.

[0272] Alternatively, the transmitting / receiving unit 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 control unit 210 may control the reception of the channel state information reference signal, which supports at least one mapping of different ports and different CDM groups for multiple resource blocks (Aspect 2-2 of the second embodiment).

[0273] The transmitting / receiving unit 220 may receive frequency domain allocation information for a channel state reference signal, which includes a bitmap showing subcarriers in multiple resource blocks. The size of the bitmap may be variable depending on the frequency domain density. The transmitting / receiving unit 220 receives the frequency domain allocation information for the channel state reference signal, and the control unit 210 may apply a predetermined offset to the frequency domain allocation information for the channel state reference signal to control the reception of the channel state information reference signal.

[0274] Alternatively, the transmitting / receiving unit 220 may receive information regarding the start symbol of the channel state information reference signal. If multiple start symbols are included in a slot, the control unit 210 may control the 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 transmitting / receiving unit 220 may receive a plurality of bitmaps indicating the frequency domain assignment of channel state information corresponding to each start symbol. If a slot contains a first start symbol and a second start symbol, the frequency domain position of the channel state reference signal corresponding to the second start symbol may have a predetermined offset applied to the 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) Note that the block diagrams used in the description of the above embodiments show blocks of functional units. These functional blocks (components) are realized by any combination of at least one of hardware and software. Also, the method of realizing each functional block is not particularly limited. That is, each functional block may be realized using one physically or logically combined device, or two or more physically or logically separated devices may be directly or indirectly connected (for example, using wired, wireless, etc.) and realized using these multiple devices. The functional block may be realized by combining software with the above one device or the above multiple devices.

[0277] Here, functions include, but are not limited to, judgment, decision, determination, calculation, computation, processing, derivation, investigation, search, confirmation, reception, transmission, output, access, solution, selection, selection determination, establishment, comparison, assumption, expectation, regarded as, notification (broadcasting), notification (notifying), communication (communicating), forwarding, configuration (configuring), reconfiguration (reconfiguring), allocation (allocating, mapping), assignment (assigning), etc. For example, a functional block (component) that functions as transmission may be referred to as a transmission unit, a transmitter, etc. In any case, as described above, the realization method is not particularly limited.

[0278] For example, a base station, a user terminal, etc. in an embodiment of the present disclosure may function as a computer that performs the processing of the wireless communication method of the present disclosure. FIG. 25 is a diagram showing 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, and unit are interchangeable. The hardware configuration of the base station 10 and the user terminal 20 may include one or more of the devices shown in the figure, or it may be configured to omit some of the devices.

[0280] For example, although only one processor 1001 is shown in the diagram, there may be multiple processors. Furthermore, processing may be performed by one processor, or by two or more processors simultaneously, sequentially, or by other means. Note that processor 1001 may be implemented using 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 the processor 1001 and memory 1002, which allows the processor 1001 to perform calculations and control communication via the communication device 1004, or to control at least one of the reading and writing of data in the memory 1002 and storage 1003.

[0282] The processor 1001 controls the entire computer, for example, by running an operating system. The processor 1001 may be composed of a central processing unit (CPU) that includes interfaces with peripheral devices, control units, arithmetic units, registers, etc. For example, at least a part of the control unit 110 (210) and the transmitting / receiving unit 120 (220) described above may be implemented by the processor 1001.

[0283] Furthermore, the processor 1001 reads programs (program code), 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 accordingly. The program used is one that causes the computer to execute at least a part of the operations described in the above embodiment. For example, the control unit 110 (210) may be implemented by a control program stored in the memory 1002 and running on the processor 1001, and other functional blocks may be implemented similarly.

[0284] Memory 1002 is a computer-readable recording medium and may consist of at least one of the following: Read Only Memory (ROM), Erasable Programmable ROM (EPROM), Electrically EPROM (EEPROM), Random Access Memory (RAM), or other suitable storage medium. Memory 1002 may also be called a register, cache, or main memory. Memory 1002 can store executable programs (program code), software modules, etc., for carrying out a wireless communication method according to one embodiment of this disclosure.

[0285] Storage 1003 is a computer-readable recording medium and may consist of at least one of the following: a flexible disk, a floppy disk, a magneto-optical disk (e.g., a compact disk (Compact Disc ROM (CD-ROM)), a digital multipurpose disk, a Blu-ray disk), 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 called an auxiliary storage device.

[0286] The communication device 1004 is hardware (transmitting / receiving device) for communicating between computers via at least one of a wired network and a wireless network, and is also referred to as a network device, network controller, network card, communication module, etc. The communication device 1004 may be configured to include, for example, a high-frequency switch, duplexer, filter, frequency synthesizer, etc., in order to implement at least one of frequency division duplex (FDD) and time division duplex (TDD). For example, the above-mentioned transmitting / receiving unit 120 (220), transmitting / receiving antenna 130 (230), etc., may be implemented by the communication device 1004. The transmitting / receiving unit 120 (220) may be implemented with physically or logically separated implementations of a transmitting unit 120a (220a) and a receiving unit 120b (220b).

[0287] The input device 1005 is an input device that accepts input from an external source (e.g., a keyboard, mouse, microphone, switch, button, sensor, etc.). The output device 1006 is an output device that outputs to an external source (e.g., a display, speaker, light-emitting diode (LED) lamp, etc.). The input device 1005 and the output device 1006 may be configured as an integrated unit (e.g., a touch panel).

[0288] Furthermore, each device, such as the processor 1001 and memory 1002, is connected by a bus 1007 for communicating information. The bus 1007 may be configured using a single bus, or different buses may be configured for 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), and a field programmable gate array (FPGA), and some or all of each functional block may be implemented using such hardware. For example, the processor 1001 may be implemented using at least one of these hardware components.

[0290] (modified version) In addition, terms used in this disclosure and terms necessary for understanding this disclosure may be replaced with terms having the same or similar meanings. For example, channel, symbol, and signal (signal or signaling) may be used interchangeably. Also, a signal may be a message. A reference signal may be abbreviated as RS and may be called a pilot, pilot signal, etc., depending on the applicable standard. Also, a component carrier (CC) may be called a cell, frequency carrier, carrier frequency, etc.

[0291] A wireless frame may consist of one or more periods (frames) in the time domain. Each of these periods (frames) constituting a wireless frame may be called a subframe. Furthermore, a subframe may consist 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 neuralelogy may be communication parameters applied to at least one of the transmission and reception of a signal or channel. The neuralelogy may be, for example, at least one of the following: subcarrier spacing (SCS), bandwidth, symbol length, cyclic prefix length, transmission time interval (TTI), number of symbols per TTI, radio frame configuration, specific filtering processes performed by the transceiver in the frequency domain, or specific windowing processes performed by the transceiver in the time domain.

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

[0294] A slot may include multiple mini-slots. Each mini-slot may consist of one or more symbols in the time domain. Mini-slots may also be called sub-slots. Mini-slots may consist of fewer symbols than a slot. A PDSCH (or PUSCH) transmitted in a time unit larger than a mini-slot may be called a PDSCH (PUSCH) mapping type A. A PDSCH (or PUSCH) transmitted using a mini-slot may be called a PDSCH (PUSCH) mapping type B.

[0295] Wireless frames, subframes, slots, minislots, and symbols all represent units of time when transmitting a signal. Wireless frames, subframes, slots, minislots, and symbols may each be referred to by different names. Furthermore, the units of time such as frames, subframes, slots, minislots, and symbols in this disclosure may be interpreted as interchangeable.

[0296] For example, one subframe may be called TTI, multiple consecutive subframes may be called TTI, or one slot or one mini-slot may be called TTI. In other words, at least one of the subframe and TTI may be a subframe (1ms) in existing LTE, a period shorter than 1ms (e.g., 1-13 symbols), or a period longer than 1ms. Note that the unit representing TTI may be called a slot, mini-slot, etc., instead of a subframe.

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

[0298] TTI may be a transmission time unit for channel-encoded data packets (transport blocks), code blocks, code words, etc., or it may be a processing unit for scheduling, link adaptation, etc. Given a TTI, the actual time interval (e.g., number of symbols) to which the transport block, code block, code word, etc. are mapped may be shorter than the given TTI.

[0299] Furthermore, if one slot or one mini-slot is referred to as TTI, then one or more TTIs (i.e., one or more slots or one or more mini-slots) may constitute the minimum time unit of scheduling. In addition, the number of slots (number of mini-slots) that constitute the minimum time unit of scheduling may be controlled.

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

[0301] Furthermore, long TTIs (e.g., normal TTIs, subframes, etc.) may be interpreted as TTIs with a time length exceeding 1 ms, and short TTIs (e.g., shortened TTIs, etc.) may be interpreted as TTIs with a TTI length less than that of a long TTI but 1 ms or more.

[0302] A Resource Block (RB) is a resource allocation unit in the time domain and frequency domain, and in the frequency domain, it may contain one or more consecutive subcarriers. The number of subcarriers in an RB may be the same regardless of the neurology, for example, 12. The number of subcarriers in an RB may be determined based on the neurology.

[0303] Furthermore, an RB may contain one or more symbols in the time domain and may have the length of one slot, one minislot, one subframe, or one TTI. Each TTI, subframe, etc., may consist of one or more resource blocks.

[0304] One or more RBs may also be called Physical RBs (PRBs), Sub-Carrier Groups (SCGs), Resource Element Groups (REGs), PRB pairs, RB pairs, etc.

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

[0306] A Bandwidth Part (BWP) (also called a partial bandwidth) may represent a subset of consecutive common resource blocks (RBs) for a given neurology in a given carrier. Here, the common RBs may be identified by an index of the RBs relative to the carrier's common reference point. PRBs may be defined and numbered within a BWP.

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

[0308] At least one of the configured BWPs may be active, and the UE does not need to assume that it will send or receive a given signal / channel outside of the active BWP. In this disclosure, terms such as "cell" and "carrier" may be read as "BWP".

[0309] The structures described above, such as wireless frames, subframes, slots, minislots, and symbols, are merely illustrative examples. For instance, the number of subframes included in a wireless frame, the number of slots per subframe or wireless frame, the number of minislots within a slot, the number of symbols and RBs included in a slot or minislot, the number of subcarriers included in an RB, and the number of symbols, symbol length, and cyclic prefix (CP) length within a TTI can be varied in various ways.

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

[0311] The names used for parameters and other elements in this disclosure are not restrictive in any way. Furthermore, mathematical formulas and other elements that use these parameters may differ from those expressly disclosed in this disclosure. Various channels (PUCCH, PDCCH, etc.) and information elements can be identified by any suitable name, and therefore, the various names assigned to these various channels and information elements are not restrictive in any way.

[0312] The information, signals, etc. described in this disclosure may be represented using any of the various different techniques. For example, the data, instructions, commands, information, signals, bits, symbols, chips, etc. that may be referred to throughout the above description may be represented by voltage, current, electromagnetic waves, magnetic fields or magnetic particles, optical fields or photons, or any combination thereof.

[0313] Furthermore, information, signals, etc., can be output from upper layers to lower layers and from lower layers to upper layers, or to at least one of the two. Information, signals, etc., may also be input and output via multiple network nodes.

[0314] Input and output information and signals may be stored in a specific location (e.g., memory) or managed using a management table. Input and output information and signals may be overwritten, updated, or appended to. Output information and signals may be deleted. Input information and signals may be transmitted to other devices.

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

[0316] Physical layer signaling may also be called Layer 1 / Layer 2 (L1 / L2) control information (L1 / L2 control signals), L1 control information (L1 control signals), etc. RRC signaling may also be called RRC messages, for example, RRC Connection Setup messages, RRC Connection Reconfiguration messages, etc. MAC signaling may also be communicated using, for example, MAC Control Element (CE).

[0317] Furthermore, notification of the specified information (for example, notification that "X is the case") is not limited to explicit notification, but may also be made implicitly (for example, by not providing notification of the specified information or by providing notification of other information).

[0318] The determination may be made by a value represented by 1 bit (0 or 1), by a boolean value represented as true or false, or by a numerical comparison (for example, a comparison with a predetermined value).

[0319] Software should be broadly interpreted to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software modules, applications, software applications, software packages, routines, subroutines, objects, executable files, execution threads, procedures, functions, and so on, whether they are called software, firmware, middleware, microcode, hardware description languages, or by any other name.

[0320] Furthermore, software, instructions, information, etc., may be transmitted and received via a transmission medium. For example, if software is transmitted from a website, server, or other remote source using at least one of wired technology (such as coaxial cable, fiber optic cable, twisted pair, or Digital Subscriber Line (DSL)) and wireless technology (such as infrared or microwave), then at least one of these wired and wireless technologies is included in the definition of a transmission medium.

[0321] The terms “system” and “network” as used in this disclosure may be used interchangeably. “Network” may also mean the equipment included in the network (e.g., base stations).

[0322] In this disclosure, terms such as "precoding," "precoder," "weight (precoding weight)," "quasi-co-location (QCL)," "transmission configuration indication state (TCI state)," "spatial relation," "spatial domain filter," "transmit power," "phase rotation," "antenna port," "antenna port group," "layer," "number of layers," "rank," "resource," "resource set," "resource group," "beam," "beam width," "beam angle," "antenna," "antenna element," and "panel" may be used interchangeably.

[0323] In this disclosure, terms such as "Base Station (BS)", "wireless 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", and "component carrier" may be used interchangeably. Base stations may also be referred to by terms such as macrocell, small cell, femtocell, and picocell.

[0324] A base station can house one or more (e.g., three) cells. If a base station houses multiple cells, the entire coverage area of ​​the base station can be divided into several smaller areas, each of which may also be provided with communication services by a base station subsystem (e.g., a small indoor base station (Remote Radio Head (RRH))). The terms “cell” or “sector” refer to part or all of the coverage area of ​​at least one of the base station and / or base station subsystems that provide communication services in that coverage.

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

[0326] A mobile station may also be called 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 appropriate term.

[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. At least one of the base station and the mobile station may also be a device mounted on a moving object, the moving object itself, etc.

[0328] The term "mobile object" refers to any movable object, regardless of its speed, and naturally includes cases where the mobile object is stationary. Examples of such mobile objects include, but are not limited to, vehicles, transport vehicles, automobiles, motorcycles, bicycles, connected cars, excavators, bulldozers, wheel loaders, dump trucks, forklifts, trains, buses, handcarts, rickshaws, ships and other watercraft, airplanes, rockets, satellites, drones, multicopters, quadcopters, balloons, and items carried on them. Furthermore, such mobile objects may be autonomously driven objects operating based on operational commands.

[0329] The mobile entity may be a vehicle (e.g., a car, an airplane), an unmanned mobile entity (e.g., a drone, an autonomous vehicle), or a robot (manned or unmanned). At least one of the base station and the mobile station may be a device that does 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] Figure 26 shows an example of a vehicle according to one embodiment. The vehicle 40 includes a drive unit 41, a steering unit 42, an accelerator pedal 43, a brake pedal 44, a shift lever 45, left and right front wheels 46, left and right rear wheels 47, an axle 48, an electronic control unit 49, various sensors (including a current sensor 50, a rotation speed sensor 51, a pneumatic 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 consists of, for example, at least one of an engine, a motor, or an engine-motor hybrid. 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 consists of a microprocessor 61, memory (ROM, RAM) 62, and communication ports (e.g., input / output (IO) ports) 63. Signals from various sensors 50-58 installed in the vehicle are input to the electronic control unit 49. The electronic control unit 49 may also be called an Electronic Control Unit (ECU).

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

[0334] The information service unit 59 consists of various devices for providing (outputting) various types of information such as driving information, traffic information, and entertainment information, including a car navigation system, audio system, speakers, displays, television, and radio, and one or more ECUs that control these devices. The information service unit 59 uses information acquired from external devices via a communication module 60 or the like to provide various types of information / services (e.g., multimedia information / multimedia services) to the occupants of the vehicle 40.

[0335] The information service unit 59 may include input devices that accept input from the outside (e.g., keyboard, mouse, microphone, switch, button, sensor, touch panel, etc.) and output devices that perform output to the outside (e.g., display, speaker, LED lamp, touch panel, etc.).

[0336] The driver assistance system unit 64 consists of various devices that provide functions to prevent accidents or reduce the driver's workload, 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 Unit (IMU), Inertial Navigation System (INS)), artificial intelligence (AI) chips, and AI processors, as well as one or more ECUs that control these devices. The driver assistance system unit 64 also transmits and receives various information via the communication module 60 to realize driver 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 sends and receives data (information) via the communication port 63 to 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, axle 48, the microprocessor 61 and memory (ROM, RAM) 62 in the electronic control unit 49, and various sensors 50-58 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 external devices. For example, it can send and receive various types of information to and from external devices 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 base station 10 or the user terminal 20 described above. Alternatively, the communication module 60 may be, for example, at least one of the base station 10 and the user terminal 20 (it may function as at least one of the base station 10 and the user terminal 20).

[0339] The communication module 60 may transmit at least one of the following to an external device via wireless communication: signals from the various sensors 50-58 input to the electronic control unit 49, information obtained based on said signals, and information based on input from an external source (user) obtained via the information service unit 59. The electronic control unit 49, the various sensors 50-58, the information service unit 59, etc., may also be called input units that accept input. For example, the PUSCH transmitted by the communication module 60 may include information based on the above input.

[0340] The communication module 60 receives various information (traffic information, signal information, inter-vehicle information, etc.) transmitted from an external device and displays it on the information service unit 59 installed in the vehicle. The information service unit 59 may also be called an output unit, which outputs information (for example, it outputs information to devices such as displays and speakers based on the PDSCH (or data / information decoded from the PDSCH) received by the communication module 60).

[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, axle 48, various sensors 50-58, etc., which are provided in the vehicle 40.

[0342] Furthermore, the term "base station" in this disclosure may be interpreted as "user terminal." For example, the various aspects / embodiments of this disclosure may be applied to a configuration in which communication between a base station and a user terminal is replaced with communication between multiple user terminals (which may be called, for example, Device-to-Device (D2D), Vehicle-to-Everything (V2X)). In this case, the user terminal 20 may have the functions that the base station 10 has. Also, terms such as "uplink" and "downlink" may be interpreted as terms corresponding to terminal-to-terminal communication (for example, "sidelink"). For example, uplink channel and downlink channel may be interpreted as sidelink channel.

[0343] Similarly, the term "user terminal" in this disclosure may be replaced with "base station." In this case, the base station 10 may be configured to have the same functions as the user terminal 20 described above.

[0344] In this disclosure, operations performed by a base station may, in some cases, be performed by its upper node. In a network including one or more network nodes with base stations, it is clear that various operations performed for communication with terminals may be performed by the base station, one or more network nodes other than the base station (for example, a Mobility Management Entity (MME), a Serving Gateway (S-GW), etc., but not limited to these), or a combination thereof.

[0345] Each aspect / embodiment described in this disclosure may be used individually, in combination, or switched between during execution. Furthermore, the processing procedures, sequences, flowcharts, etc., of each aspect / embodiment described in this disclosure may be rearranged in order, provided they are consistent. For example, the methods described in this disclosure present various step elements in an exemplary order and are not limited to that specific order.

[0346] Each aspect / embodiment described in this disclosure includes Long Term Evolution (LTE), LTE-Advanced (LTE-A), LTE-Beyond (LTE-B), SUPER 3G, IMT-Advanced, 4th generation mobile communication system (4G), 5th generation mobile communication system (5G), 6th generation mobile communication system (6G), xth generation mobile communication system (xG (where x is, for example, an integer or decimal)), 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®), CDMA2000, Ultra Mobile Broadband (UMB), IEEE 802.11 (Wi-Fi®), IEEE 802.16 (WiMAX®), and IEEE This may apply to systems utilizing 802.20, Ultra-WideBand (UWB), Bluetooth®, or other appropriate wireless communication methods, as well as next-generation systems that are extended, modified, created, or defined based on these. It may also apply to combinations of multiple systems (e.g., a combination of LTE or LTE-A and 5G).

[0347] In this disclosure, the phrase "based on" does not mean "based solely on" unless otherwise specified. In other words, the phrase "based on" means both "based solely on" and "based at least on."

[0348] Any reference to elements using the designations “first,” “second,” etc., as used in this disclosure does not generally limit the quantity or order of those elements. These designations may be used in this disclosure as a convenient way to distinguish between two or more elements. Accordingly, the references to the first and second elements do not imply that only two elements may be employed or that the first element must precede the second element in any way.

[0349] The term “determining” as used in this disclosure may encompass a wide variety of actions. For example, “determining” may be considered to include judging, calculating, computing, processing, deriving, investigating, looking up, searching, inquiry (e.g., searching in tables, databases, or other data structures), ascertaining, etc.

[0350] Furthermore, "judgment (decision)" may be considered as "judging (deciding)" things like receiving (e.g., receiving information), transmitting (e.g., sending information), input, output, accessing (e.g., accessing data in memory).

[0351] Furthermore, "judgment (decision)" can be considered as "judging (deciding)" something like resolving, selecting, choosing, establishing, comparing, etc. In other words, "judgment (decision)" can be considered as "judging (deciding)" something about an action.

[0352] Furthermore, "judgment (decision)" can be replaced with "assuming," "expecting," or "considering."

[0353] As used in this disclosure, the terms “connected,” “coupled,” and any variations thereof mean any direct or indirect connection or coupling between two or more elements, and may include one or more intermediate elements between two elements that are “connected” or “coupled” with each other. The coupling or connection between elements may be physical, logical, or a combination thereof. For example, “connection” may be replaced with “access.”

[0354] In this disclosure, when two elements are connected, they can be considered to be “connected” or “coupled” to each other using one or more wires, cables, printed electrical connections, etc., and, in some non-exclusive and non-exclusive examples, electromagnetic energy having wavelengths in the radio frequency domain, microwave domain, or optical domain (both visible and invisible).

[0355] In this disclosure, the term "A and B are different" may mean "A and B are different from each other." The term may also mean "A and B are each different from C." Terms such as "separate" and "combine" may be interpreted similarly to "different."

[0356] Where the terms “include,” “including,” and variations thereof are used in this disclosure, these terms are intended to be inclusive, as is the term “comprising.” Furthermore, the term “or” as used in this disclosure is not intended to mean exclusive OR.

[0357] In this disclosure, if articles are added by translation, such as a, an, and the in English, this disclosure may include the fact that the noun following these articles is plural.

[0358] Although the invention described herein has been explained in detail above, it will be clear to those skilled in the art that the invention described herein is not limited to the embodiments described herein. The invention described herein can be implemented in modified and altered forms without departing from the spirit and scope of the invention as defined by the claims. Therefore, the descriptions herein are for illustrative purposes only and do not imply any limitation on the invention described herein.

Claims

1. A receiving unit that receives information regarding the start symbol of the channel state information reference signal, A terminal having a control unit that controls the reception of the channel state information reference signal, in which a frequency domain resource is set separately for each start symbol if multiple start symbols are included in the slot.

2. The terminal according to claim 1, wherein the receiving unit receives a plurality of bitmaps indicating the frequency domain assignment of the channel state information corresponding to each start symbol.

3. The terminal according to claim 1, wherein, if the slot contains a first start symbol and a second start symbol, the frequency domain position of the channel state reference signal corresponding to the second start symbol is such that a predetermined offset is applied to the frequency domain position of the channel state reference signal corresponding to the first start symbol.

4. The terminal according to any one of claims 1 to 3, wherein the number of CDM groups mapped to each start symbol can be set differently.

5. The terminal according to any one of claims 1 to 3, wherein the control unit measures the channel state information reference signal, performs machine learning on the measurement results, and estimates the channel using the machine learning interpolation.

6. A step of receiving information regarding the start symbol of the channel state information reference signal, A wireless communication method for a terminal, comprising the step of controlling the reception of the channel state information reference signal, in which a frequency domain resource is set separately for each start symbol when multiple start symbols are included in the slot.

7. A transmitting unit that transmits information about the start symbol of the channel state information reference signal, A base station having a control unit that controls the transmission of the channel state information reference signal, in which a frequency domain resource is set separately for each start symbol if multiple start symbols are included in the slot.

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