Terminal, wireless communication method, and base station

Abstract

A terminal according to one aspect of the present disclosure is characterized by comprising: a control unit that determines the positions of a first time domain and a frequency domain of a first channel state information reference signal (CSI-RS) to which a frequency density of less than 0.5 is applied, and the positions of a second time domain and a frequency domain of a second CSI-RS to which a frequency density of 0.5 or greater is applied; and a reception unit that receives the first CSI-RS transmitted at the positions of the first time domain and the frequency domain and / or the second CSI-RS transmitted at the positions of the second time domain and the frequency domain. According to one aspect of the present disclosure, the frequency density of the CSI-RS can be suitably reduced.

Description

Terminal, wireless communication method, and base station

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

[0002] In the Universal Mobile Telecommunications System (UMTS) network, Long Term Evolution (LTE) was specified with the aim of achieving even higher data rates and lower latency (Non-Patent Literature 1). Furthermore, LTE-Advanced (3GPP Rel. 10-14) was specified with the aim of further increasing the 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) are also being considered.

[0004] 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

[0005] Future wireless communication systems (e.g., Rel. 19 and beyond) are considering supporting a channel state information reference signal (CSI-RS) codebook scheme with more than 32 ports. However, there are concerns about increased overhead in the frequency domain when a larger number of ports are deployed / implemented.

[0006] However, the reduction of density in the frequency domain of CSI-RS has not been sufficiently considered. In this case, the reduction of density in the frequency domain of CSI-RS may not be achieved, and overhead may increase.

[0007] Therefore, one of the objectives of this disclosure is to provide a terminal, a wireless communication method, and a base station that can suitably reduce the frequency density of CSI-RS.

[0008] A terminal according to one aspect of the present disclosure is characterized by comprising: a control unit that determines the positions of a first time domain and a frequency domain of a first channel state information reference signal (CSI-RS) to which a frequency density of less than 0.5 is applied, and the positions of a second time domain and a frequency domain of a second CSI-RS to which a frequency density of 0.5 or more is applied; and a receiving unit that receives at least one of the first CSI-RS transmitted at the positions of the first time domain and the frequency domain, and the second CSI-RS transmitted at the positions of the second time domain and the frequency domain.

[0009] According to one aspect of this disclosure, the frequency density of CSI-RS can be suitably reduced.

[0010] Figure 1 shows an example of the CSI-RS location within a slot. Figure 2 shows an example of the total number of CSI-RS ports P across aggregated resources and the combination of (N1, N2) in an extended CB based on a Type 1 CB. Figure 3 shows an example of a case where the frequencies differ between existing CSI-RS resources and additional CSI-RS resources. Figure 4 shows an example of a case where the times differ between existing CSI-RS resources and additional CSI-RS resources. Figures 5A / 5B show an example of option 3 of embodiment B. Figures 6A / 6B show an example of option 3-1 of embodiment C. Figures 7A / 7B show an example of option 3-2 of embodiment C. Figure 8 shows an example of the CSI-RS location within a slot. Figure 9 shows an example of the CSI-RS location within a slot. Figure 10 shows an example of the CSI-RS location within a slot. Figures 11A and 11B show an example of the position of the CSI-RS in the slot. Figures 12A and 12B show an example of the position of the CSI-RS in the slot. Figure 13 shows an example of the schematic configuration of a wireless communication system according to one embodiment. Figure 14 shows an example of the configuration of a base station according to one embodiment. Figure 15 shows an example of the configuration of a user terminal according to one embodiment. Figure 16 shows an example of the hardware configuration of a base station and user terminal according to one embodiment. Figure 17 shows an example of a vehicle according to one embodiment.

[0011] (CSI Reporting) Rel. 15 In NR, a terminal (also called a user terminal, User Equipment (UE), etc.) generates (also called determining, calculating, estimating, measuring, etc.) Channel State Information (CSI) based on a Reference Signal (RS) (or a resource for said RS), and transmits (also called reporting, feedback, etc.) the generated CSI to the network (e.g., a base station). The CSI may be transmitted to the base station using, for example, an uplink control channel (e.g., a Physical Uplink Control Channel (PUCCH)) or an uplink shared channel (e.g., a Physical Uplink Shared Channel (PUSCH)).

[0012] The RS used to generate the CSI may be at least one of the following: Channel State Information Reference Signal (CSI-RS), Synchronization Signal / Physical Broadcast Channel (SS / PBCH) block, Synchronization Signal (SS), or Demodulation Reference Signal (DMRS).

[0013] The CSI-RS may include at least one of Non Zero Power (NZP) CSI-RS and CSI-Interference Management (CSI-Interference Measurement, CSI-IM). The SS / PBCH block is a block that includes SS and PBCH (and corresponding DMRS), and may be called an SS block (SSB), etc. The SS may also include at least one of a Primary Synchronization Signal (PSS) and a Secondary Synchronization Signal (SSS).

[0014] Furthermore, CSI may include at least one of the following: Channel Quality Indicator (CQI), Precoding Matrix Indicator (PMI), CSI-RS Resource Indicator (CRI), SS / PBCH Block Resource Indicator (SSBRI), Layer Indicator (LI), Rank Indicator (RI), L1-RSRP (Layer 1 Reference Signal Received Power), L1-RSRQ (Reference Signal Received Quality), L1-SINR (Signal to Interference plus Noise Ratio), L1-SNR (Signal to Noise Ratio).

[0015] The UE may receive information regarding CSI reporting (report configuration information) and control CSI reporting based on that report configuration information. This report configuration information may be, for example, the "CSI-ReportConfig" information element (IE) of Radio Resource Control (RRC).

[0016] The reporting configuration information (for example, "CSI-ReportConfig" in RRC IE) may include, for example, at least one of the following: ◆ Information about the type of CSI report (report type information, for example, "reportConfigType" in RRC IE) ◆ Information about one or more quantities (one or more CSI parameters) of CSI to be reported (report quantity information, for example, "reportQuantity" in RRC IE) ◆ Information about the RS resources used to generate the quantity (the CSI parameter) (resource information, for example, "CSI-ResourceConfigId" in RRC IE) ◆ Information about the frequency domain to which the CSI report is applied (frequency domain information, for example, "reportFreqConfiguration" in RRC IE)

[0017] For example, the reporting type information may indicate a periodic CSI (P-CSI) report, an aperiodic CSI (A-CSI) report, or a semi-persistent CSI (SP-CSI) report.

[0018] Furthermore, the reported quantity information may specify at least one combination of the above-mentioned CSI parameters (e.g., CRI, RI, PMI, CQI, LI, L1-RSRP, etc.).

[0019] Furthermore, the resource information may also be the ID of the RS resource. The RS resource may include, for example, a non-zero power CSI-RS resource or SSB and a CSI-IM resource (for example, a zero-power CSI-RS resource).

[0020] Furthermore, frequency domain information may indicate the frequency granularity of the CSI report. This frequency granularity may include, for example, wideband and subband. The wideband is the entire CSI reporting band. The wideband may be, for example, the entire carrier (component carrier (CC), cell, serving cell) or the entire bandwidth part (BWP) within a carrier. The wideband may also be referred to as the CSI reporting band, the entire CSI reporting band, etc.

[0021] Furthermore, a subband may be part of the wideband and may consist of one or more resource blocks (Resource Blocks (RBs) or Physical Resource Blocks (PRBs)). The size of the subband may be determined according to the size of the BWP (number of PRBs).

[0022] Frequency domain information may indicate whether to report wideband or subband PMI (frequency domain information may include, for example, the RRC IE's "pmi-FormatIndicator" used to determine whether to report wideband PMI or subband PMI). Based on at least one of the above-mentioned reporting quantity information and frequency domain information, the UE may determine the frequency granularity of the CSI report (i.e., whether to report wideband PMI or subband PMI).

[0023] If wideband PMI reporting is established (decided), one wideband PMI may be reported for the entire CSI reporting band. On the other hand, if subband PMI reporting is established, a single wideband indication i1 may be reported for the entire CSI reporting band, and one subband indication i2 (e.g., subband indication for each subband) may be reported for one or more subbands within the entire CSI reporting band.

[0024] The UE performs channel estimation using the received RS and estimates the channel matrix H. The UE then feeds back the index (PMI) determined based on the estimated channel matrix.

[0025] PMI may represent a precoder matrix (also simply called a precoder) that a UE considers appropriate for use in downlink (DL) transmissions to the UE. Each value of PMI may correspond to a single precoder matrix. A set of PMI values ​​may correspond to a different set of precoder matrices called a precoder codebook (also simply called a codebook).

[0026] In a spatial domain, a CSI report may include one or more types of CSIs. For example, the CSI may include at least one of a first type (Type 1 CSI) used for single-beam selection and a second type (Type 2 CSI) used for multi-beam selection. A single beam may be rephrased as a single layer, and a multi-beam as multiple beams. Furthermore, a Type 1 CSI may not assume multi-user multiple input multiple output (MU-MIMO), while a Type 2 CSI may assume multi-user MIMO.

[0027] The above codebooks may include a codebook for Type 1 CSI (also referred to as a Type 1 codebook, etc.) and a codebook for Type 2 CSI (also referred to as a Type 2 codebook, etc.). Furthermore, Type 1 CSI may include Type 1 single-panel CSI and Type 1 multi-panel CSI, and different codebooks (Type 1 single-panel codebook and Type 1 multi-panel codebook) may be specified for each.

[0028] In this disclosure, Type 1 and Type I may be interpreted as interchangeable. In this disclosure, Type 2 and Type II may be interpreted as interchangeable.

[0029] The Upbound Control Information (UCI) type may include at least one of Hybrid Automatic Repeat reQuest ACKnowledgement (HARQ-ACK), scheduling request (SR), or CSI. The UCI may be carried by PUCCH or by PUSCH.

[0030] In Rel. 15 NR, the UCI may include one CSI part for wideband PMI feedback. CSI report #n includes PMI wideband information, if reported.

[0031] In Rel. 15 NR, the UCI may include two CSI parts for subband PMI feedback. CSI part 1 contains wideband PMI information. CSI part 2 contains one wideband PMI piece and several subband PMI pieces. CSI parts 1 and 2 are encoded separately.

[0032] In Rel. 15 NR, the UE is configured by a higher layer with N (N≧1) CSI reporting settings and M (M≧1) CSI resource settings. For example, a CSI reporting setting (CSI-ReportConfig) includes a resource setting for channel measurement (resourcesForChannelMeasurement), a CSI-IM resource setting for interference (csi-IM-ResourceForInterference), an NZP-CSI-RS resource setting for interference (nzp-CSI-RS-ResourceForInterference), and a report quantity (reportQuantity). Each of the resource settings for channel measurement, the CSI-IM resource setting for interference, and the NZP-CSI-RS setting for interference is associated with a CSI resource setting (CSI-ResourceConfig, CSI-ResourceConfigId). The CSI resource configuration includes a list of CSI-RS resource sets (csi-RS-ResourceSetList, e.g., NZP-CSI-RS resource set or CSI-IM resource set).

[0033] To enable more dynamic channel / interference hypotheses for NCJT, targeting both FR1 and FR2, evaluation and specification of CSI reporting for at least one multi-TRP and multi-panel transmission of DL are being considered.

[0034] (Codebook Configuration) The UE configures the parameters related to the codebook (CB) (Codebook Configuration) via upper-layer signaling (RRC signaling). The codebook configuration is included in the upper-layer (RRC) parameter CSI-ReportConfig.

[0035] In the codebook configuration, at least one codebook is selected from among several codebooks, including type I single panel (typeI-SinglePanel), type I multi-panel (typeI-MultiPanel), type II, and type II port selection (typeII-PortSelection).

[0036] The codebook parameters include parameters related to codebook subset restrictions (CBSRs) ("...Restriction" in CodebookConfig). The CBSR setting is a bit that indicates which PMI reports are allowed ("1") and which are not allowed ("0") for the precoder associated with the CBSR bit. Each bit in the CBSR bitmap corresponds to one codebook index / antenna port.

[0037] (CSI Reporting Settings) The CSI reporting settings (CSI-ReportConfig) in Rel. 16 include, in addition to the codebook settings (CodebookConfig), channel measurement resources (CMR), interference measurement resources (IMR), etc. The IMR may be at least one of zero power-interference measurement resources (ZP-IMR) and non-zero power-interference measurement resources (NZP-IMR). Of the parameters of CSI-ReportConfig, all parameters except codebookConfig-r16 are also included in the CSI reporting settings in Rel. 15.

[0038] In this disclosure, CMR, NZP CSI-RS resources, and resourcesForChannelMeasurement may be interpreted as interchangeable. In this disclosure, ZP-IMR, CSI-IM resources, and csi-IM-ResourcesForInterference may be interpreted as interchangeable. In this disclosure, NZP-IMR, NZP CSI-RS resources for interferometry, and nzp-CSI-RS-ResourcesForInterference may be interpreted as interchangeable.

[0039] In Rel. 17, an extended CSI reporting configuration (CSI-ReportConfig) for CSI measurement / reporting of multi-TRP using NCJT is considered. In this CSI reporting configuration, two CMR groups are set up, corresponding to each of the two TRPs. The CMRs within each CMR group may be used for at least one measurement of multi-TRP and single-TRP using NCJT. The N CMR pairs of NCJT are set up by RRC signaling. The UE may be set by RRC signaling whether to use the CMRs of the CMR pair for single-TRP measurement.

[0040] For CSI reporting related to multi-TRP / panel NCJT measurements, configured by a single CSI reporting setting, it is being considered that at least one of the following options 1 and 2 should be supported.

[0041] <Option 1> The UE is configured to report X CSIs (X = 0, 1, 2) related to single TRP measurement hypotheses / assumptions and one CSI related to the NCJT measurement. If X = 2, the two CSIs are related to two different single TRP measurements using CMRs from different CMR groups.

[0042] <Option 2> The UE may be configured to report one CSI that corresponds to the best measurement result among the measurement hypotheses for NCJT and single TRP.

[0043] As mentioned above, in Rel. 15 / 16, CBSR is set for each codebook setting for each CSI reporting setting. In other words, CBSR applies to all CMRs, etc., within the corresponding CSI reporting setting.

[0044] However, with the CSI reporting settings for Rel. 17 for multi-TRP systems, applying options 1 and 2 above may result in the following measurement settings: ◆ Option 1 (X=0): Measurement of NCJT CSI only. ◆ Option 1 (X=1): Measurement of NCJT CSI and single TRP (one TRP). ◆ Option 1 (X=2): Measurement of NCJT CSI and single TRP (two TRPs). ◆ Option 2: Measurement of both NCJT CSI and single TRP CSI.

[0045] Multiple subbands for a given CSI report #n, as indicated by the upper layer parameter csi-ReportingBand, may be numbered sequentially in ascending order, with the lowest subband of csi-ReportingBand as subband 0.

[0046] (PMI / Type 1 Codebook) The Type 1 codebook (Rel. 15) specifies both a Type 1 single-panel codebook and a Type 1 multi-panel codebook for base station panels. For the Type 1 single panel, the antenna model (antenna configuration) of the CSI antenna port array (logical configuration) is specified for (N1,N2). CSI-RS antenna port count P CSI-RS It is 2N1N2. In a Type 1 multi-panel, the number of CSI-RS antenna ports P CSI-RS And, (N g For N1 and N2, the antenna model of the CSI antenna port array (logical configuration) is defined.

[0047] In this disclosure, the first dimension, the N1 dimension, one of the horizontal domain and the vertical domain, and the horizontal domain may be interpreted as mutually exclusive. In this disclosure, the second dimension, the dimension perpendicular to the first dimension, the N2 dimension, the other of the horizontal domain and the vertical domain, and the vertical domain may be interpreted as mutually exclusive. In this disclosure, N1 and N2 may be substituted for each other, and the horizontal domain and the vertical domain may be substituted for each other.

[0048] In this disclosure, the terms N1 x N2 DFT vector, spatial domain (SD) vector, 2D-DFT vector, SD DFT vector, SD basis vector, SD beam, and SD basis may be interpreted as interchangeable.

[0049] In this disclosure, the terms port, antenna port, CSI-RS port, port index, and port number may be interpreted interchangeably.

[0050] In this disclosure, (N1, N2), the number of antenna ports in two dimensions, the antenna configuration, and the base station antenna layout may be interpreted as interchangeable. g The terms "number of panels," "number of antenna groups," and "number of antenna port groups" may be interchangeable.

[0051] In this disclosure, two polarizations, a first polarization and a second polarization, horizontal polarization and vertical polarization may be interpreted as interchangeable. In this disclosure, one polarization, one of the first polarization and the second polarization, and one of the horizontal polarization and vertical polarization may be interpreted as interchangeable. In this disclosure, co-phasing, phase difference, phase compensation between polarizations, and φ may be interpreted as interchangeable.

[0052] In this disclosure, the terms Type 1 codebook, Type 1 single-panel codebook, and Type 1 multi-panel codebook may be interpreted interchangeably.

[0053] ((Type 1 Single Panel Codebook)) For the Rel. 15 Type 1 Single Panel CSI, the UE sets the upper layer parameter of the codebook type (subType within type1 within codebookType within CodebookConfig) to the Type 1 Single Panel ('typeI-SinglePanel'). When the number of layers v ∉ {2, 3, 4}, the PMI value corresponds to three codebook indexes i 1,1 , i 1,2 , i2. When the number of layers v ∈ {2, 3, 4}, the PMI value corresponds to four codebook indexes i 1,1 , i 1,2 , i 1,3 , i2. When the number of layers v ∉ {2, 3, 4}, the composite codebook index i1 = [i 1,1 i 1,2 . When the number of layers v ∈ {2, 3, 4}, the composite codebook index i1 = [i 1,1 i 1,2 i 1,3 .

[0054] For P CSI-RS , the supported settings (value combinations) of (N1, N2) and (O1, O2) are specified in the specification. (N1, N2) indicates the number of 2D antenna elements and is set by the upper layer parameters n1 - n2 within nrOfAntennaPorts within moreThanTwo within typeI-SinglePanel. n1 - n2 is a bitmap parameter of N1O1N2O2 bits. (O1, O2) is the 2D oversampling factor.

[0055] The precoding matrix for v = 1 is represented as W l,m,n (v) and the precoding matrix for v = 2 is represented as W l,l',m,m',n (v) . For P CSI-RS < 16 and the precoding matrices for v = 3, 4 are represented as W l,l',m,m',n (v) and for P CSI-RSThe precoding matrix for ≥16 and v=3,4 is W l,m,p,n (v) It is expressed as follows. The precoding matrix for v=5,6 is W l,l',l'',m,m',m'',n (v) It is expressed as follows. The precoding matrix for v=7,8 is Wl,l',l'',l''',m,m',m'',m''',n (v) It is expressed as follows: l,l',l'',l''' is i 1,1 and are determined by k1. m,m',m'',m''' are i 1,2 n is determined by and k2. n is determined by i2. p is P CSI-RS Of the (≥16) ports, the first half of the ports are 0 and the second half of the ports are 1.

[0056] The precoding matrix W can be expressed as the product of two matrices W1W2. W1 represents the wideband and long-term channel properties, and the codebook index i1 (for example, i 1,1 and i 1,2 It is represented by i. 1,1 and i 1,2 The beam selection in two dimensions is shown, respectively. W2 represents the frequency selectivity (subband) and short-term channel characteristics, and is represented by the codebook index i2. i2 may also represent the phase adjustment between the two polarizations. W1 may also be given by the following equation E1 using matrix B.

[0057] B represents L 2D DFT beams, each beam oversampled by (O1,O2).

[0058] If the rank is {1, 5, 6, 7, 8}, the codebook index for each PMI is i 1,1 ,i 1,2 , i2. If the rank is {2, 3, 4}, the codebook index for each PMI is i 1,1 ,i 1,2 ,i 1,3 i2. 1,3These are mapped to k1 and k2 according to the specification table. At ranks 2, 3, and 4, the beams selected for different layers may differ when generating the PMI.

[0059] For a 1-layer CSI report and codebook mode (codebookMode) = 1, the codebook corresponds to index i, which represents the horizontal component of the beam. 1,1 =l=0,1,...,N1O1-1, and index i corresponding to the vertical component of the beam. 1,2 Includes =m=0,1,...,N2O2-1 and the corresponding subband indices i2=n=0,1,2,3. Antenna ports 3000 to 2999+P CSI-RS Precoding matrix W for one-layer CSI reporting using l,m,n (1) This is given by the following equation E2.

[0060] φ for precoding matrices n , θ p u m , v l,m , v ~ l,m This is given by the following equation E3.

[0061] Here, [i 1,1 ,i 1,2 [i2] = [l,m,n]. l,m This is the DFT vector (SD basis vector, SD beam) with N1 rows and N2 columns, expressed as exp(j2πln1 / O1N1)×exp(j2πmn2 / O2N2), where n1=0,1,...,N1-1 and n2=0,1,...,N2-1, and specified by v and l. l,m This shows one beam. Phase adjustment φ between the two polarizations. n =exp(jπn / 2), which represents the phase difference of the second polarization relative to the phase of the first polarization. θ p This shows the phase of the second half of the port relative to the phase of the first half of the port.

[0062] ((Type 1 Multi-Panel Codebook)) For Rel. 15 Type 1 Multi-Panel CSI, the UE sets the upper layer parameters of the codebook type (subType within type1 within codebookType within CodebookConfig) to the Type 1 multi-panel ('typeI-MultiPanel'). Compared with the Type 1 single-panel codebook for Rel. 15 Type 1 multi-panel CSI, in addition to N1 and N2, the number of panels N g is set. When compared with the Type 1 single-panel codebook, as the (wideband) inter-panel co-phasing (inter-panel phase compensation, phase compensation between panels), i, 1,4 is added and reported. For each panel, the same SD beam (DFT vector v l,m , SD base indices l, m) is selected, and only the inter-panel co-phasing is added and reported.

[0063] P CSI-RS For, the supported settings (combinations of values) of (N g , N1, N2) and (O1, O2) are specified in the specification. (N1, N2) is set by ng-n1-n2 within typeI-MultiPanel. i 1,1 =l={0, 1,..., N1O1 - 1} is the horizontal component of the oversampled SD base. i 1,2 =m={0, 1,..., N2O2 - 1} is the vertical component of the oversampled SD base. q = 1,..., N g -1 for i 1,4,q =p={0, 1, 2, 3} is the number of panels. i2 = n={0, 1, 2, 3} is the number of beams per panel.

[0064] The antenna setting parameters for the Type 1 multi-panel codebook are ng-n1-n2 (N g , N1, N2). In the existing specification, up to rank 4 is supported, and ranks 5 and above are not supported.

[0065] Each PMI value corresponds to codebook indices i1, i2. v is the RI value (number of layers). For v = 1, i1 = [i 1,1 i 1,2 i 1,4 . For v ∈ {2, 3, 4}, i1 = [i 1,1 i 1,2 i 1,3 i 1,4 .

[0066] When the codebook mode is set to 1, for N g = 2, i 1,4 = i 1,4,1 . For N g = 4, i 1,4 = [i 1,4,1 i 1,4,2 i 1,4,3 . When the codebook mode is set to 2, i 1,4 = [i 1,4,1 i 1,4,2 . i 1,4 is related to the number of panels N g and the codebook mode. Codebook mode 2 is supported only for N g = 2. [i 1,4,1 i 1,4,2 in codebook mode 2 corresponds to two polarization waves respectively. Each of the two values represents the wideband phase difference of the second panel (panel 1) with respect to the first panel (panel 0) in the corresponding polarization wave. For N g = 2 and codebook mode 1, only one value of i 1,4 is reported. That one value represents the wideband phase difference of the second panel (panel 1) with respect to the first panel (panel 0).

[0067] When the codebook mode is set to 2, i2 = [i 2,0 i 2,1 i 2,2It is so. The number and value of i2 are related to the codebook mode and can be different from the type 1 single panel codebook. When sub-band reporting is set, i2 is an index for the sub-band. When wide-band reporting is set, i2 is an index for the wide-band. In codebook mode 1, the number and value of i2 are the same as those of the type 1 single panel codebook, and i2 has one value for each sub-band. In codebook mode 2 (N g =2), the phase difference between sub-bands has three values and represents the phase difference between polarization and between panels.

[0068] Codebook mode 2 has a larger feedback overhead because it reports more phase differences for more accurate CSI. Also, codebook mode 2 is only supported for N g =2.

[0069] The type 1 multi-panel codebook is based on the type 1 single panel codebook. In the type 1 multi-panel codebook, the codebook of the first panel (panel 0) follows the type 1 single panel codebook. The codebooks for other panels apply the same precoder and involve additional phase differences between multiple panels.

[0070] φ n , a p , b p , u m , v l,m for the precoding matrix are given by the following equation E4.

[0071] The precoding matrix for v-layer CSI reporting using antenna ports 3000 to 2999 + P CSI-RS is represented by W (v) . The precoding matrix for the i-th layer, the number of panels N g , and codebook mode X is represented by W l,m,p,n i,N_g,X . [i 1,1 , i 1,2 , i 1,4,i2]=[l,m,p,n].

[0072] Codebook Modes 1 and N g For the value ={2,4}, the precoding matrix W for one-layer CSI reporting is used. l,m,p,n (1) is, W l,m,p,n 1,N_g,1 Represented by: Codebook Mode 1 and N g For ={2,4}, the precoding matrix W for two-layer CSI reporting is l,l',m,m',p,n (2) is (1 / sqrt(2))[W l,m,p,n (1,N_g,1) W l',m',p,n (2,N_g,1) It is represented by ]. Here, N g W for ={2,4} l,m,p,n 1,N_g,1 and W l,m,p,n 2,N_g,1 (N g W for =2 l,m,p,n 1,2,1 and W l,m,p,n 2,2,1 And, N g W for =4 l,m,p,n 1,4,1 and W l,m,p,n 2,4,1 And,) are given by the following equation E5.

[0073] Here, φ n =e jπn / 2 N g For =2, p=p1, N g For φ = 4, p = [p1, p2, p3]. p_1 , φ p_2 , φ p_3 This represents the inter-panel phase difference (inter-panel phase compensation). In each precoding matrix, the first and second rows correspond to the first panel (panel 0), the third and fourth rows correspond to the second panel (panel 1), the fifth and sixth rows correspond to the third panel (panel 2), and the seventh and eighth rows correspond to the fourth panel (panel 3). Since the same SD beam is selected for all panels, each row has the same v l,m It has. φ p_1This represents the phase difference between the second panel and the first panel. p_2 This represents the phase difference between the third panel and the first panel. p_3 This represents the phase difference between the fourth panel and the first panel.

[0074] Codebook Mode 2 and N g For =2, the precoding matrix W for one-layer CSI reporting. l,m,p,n (1) is, W l,m,p,n 1,2,1 Represented by Codebook Mode 2 and N g For =2, the precoding matrix W for two-layer CSI reporting l,l',m,m',p,n (2) is (1 / sqrt(2))[W l,m,p,n 1,2,2 W l',m',p,n 2,2,2 It is represented by ]. Here, W l,m,p,n 1,2,2 and W l,m,p,n 2,2,2 This is given by the following equation E6.

[0075] In each precoding matrix, the first and second rows correspond to the first panel (panel 0), and the third and fourth rows correspond to the second panel (panel 1). Since the same SD beam is selected for all panels, each row corresponds to the same v l,m It has p=[p1 p1] and n=[n0,n1,n2]. p_1 This represents the phase difference between the second panel (panel 1) and the first panel (panel 0) in the first polarization. p_2 This represents the phase difference between the second panel (panel 1) and the first panel (panel 0) in the second polarization. n_0 This represents the phase difference between the second polarization of the first panel and the first polarization of the first panel for each subband. n_1 This represents the phase difference between the first polarization of the second panel and the first polarization of the first panel for each subband. n_2 This represents the phase difference between the second polarization of the second panel and the first polarization of the first panel for each subband.

[0076] (PMI / Type 2 Codebook) In this disclosure, the terms Type II codebook, Extended Type II codebook, Type II port selection (PS) codebook, Extended Type II PS codebook, Additional Extended Type II port PS codebook, CJT codebook, and Doppler codebook may be interpreted as interchangeable.

[0077] ((Type II Codebook)) For a Type II codebook (Rel. 15, Type II CSI), the UE sets the upper layer parameter codebookType to 'typeII'.

[0078] In this disclosure, a matrix Z with X rows and Y columns may be denoted as Z(X×Y).

[0079] For type 2 CSI in Rel. 15, the subband-wise precoding matrix for a given layer l is based on the following equation F1: W l (N t ×N3) = W1W 2,l (F1)

[0080] N t N is the number of antennas / antenna ports. N3 is the total number of precoding (beamforming) matrices (precoders) (number of subbands) indicated by PMI.

[0081] W1(N t ×2L) represents 2L DFT vectors (oversampled DFT vectors) and indicates the selected spatial domain basis. L∈{2,4} is the number of beams per layer. The actual number of beams considering two polarizations at one location is 2L. For example, the DFT vectors of L=2 SD beams are b i ,b j It may also be expressed as follows.

[0082] W 2,l (2L×N3) is a matrix (LC coefficient matrix) consisting of linear combination coefficients (linear combination (LC) coefficients, subband complex LC coefficients, combination coefficients) for layer l.2,l This represents beam selection and the phase difference (co-phasing) between the two polarizations. For example, L = 2 SD beams b i ,b j The LC coefficients corresponding to each are c i ,c j For example, the channel vector h is a linear combination of L = 2 SD beams c i b i ,+c j b j It is approximated by the LC coefficient matrix W. The feedback overhead is mainly due to the LC coefficient matrix W. 2,l This is due to the following. Furthermore, Type 2 CSI in Rel. 15 only supports ranks 1 and 2.

[0083] In Type 2 CSI, the channel (channel matrix) for a given user is represented by a linear combination of two polarizations and L SD beams. Type 2 CSI Rel. 15 supports ranks 1 and 2.

[0084] ((Enhanced Type 2 Codebook (Rel. 16))) For Type 2 CSI (Enhanced Type 2 Codebook) Rel. 16, the UE sets the upper layer parameter codebookType to 'typeII-r16'.

[0085] Rel. 16 Type 2 CSI is compressed using frequency domain (FD) compression, resulting in the LC coefficient matrix W 2,l Reduces the overhead associated with it. Type 2 CSI Rel. 16 supports ranks 3 and 4 in addition to ranks 1 and 2.

[0086] In Type 2 CSI of Rel. 16, the precoding matrix W for a given layer l is given. l This is expressed by the following equation F2: W l = W1W ~ l W f,l H (F2)

[0087] W in Type 2 CSI of Rel. 15 2,l is, W ~ l W f,l H It is approximated by the matrix W. ~ It may also be represented by placing a tilde (~) above the W. ~ l is, W ~ 2,l It may also be expressed as: W f,l H is, W f,l The adjoint matrix of W f,l It is obtained by transposing the conjugate of .

[0088] For CSI reporting, the UE may set one of two subband sizes. That subband (CQI subband) is N PRB SB It is defined as a number of consecutive PRBs and may depend on the total number of PRBs in the BWP. The number of PMI subbands R per CQI subband is set by RRC IE (numberOfPMI-SubbandsPerCQI-Subband). R controls the total number N3 of precoding matrices represented by PMI as a function of the number of subbands set within the csi-ReportingBand, the subband size set by subbandSize, and the total number of PRBs in the BWP.

[0089] W1(N t The matrix (×2L) represents 2L DFT vectors. To represent this matrix, multiple indices of the SD basis and a two-dimensional over-sampling factor are reported.

[0090] W ~ l (2L x M) v ) is the LC coefficient matrix. To represent this matrix, up to K0 non-zero coefficients (NZCs, LC coefficients with non-zero amplitude) are reported. The report consists of two parts: a bitmap showing the NZC positions and the quantized NZCs.

[0091] W f,l (N3×M v ) is M for layer l. v The DFT vectors (frequency domain (FD), DFT vector, FD basis vector, FD beam) represent the selected frequency domain basis. Each DFT vector uses N3 FD basis (subbands). N3 is the total number of precoding (beamforming) matrices (precoders) shown by PMI as a function of the number of subbands set within the csi-ReportingBand (number of subbands). The csi-ReportingBand represents the continuous or discontinuous subbands within a given BWP (Broadwater Stream) when CSI is reported for that BWP. M per layer v There are FD DFT vectors. If N3 > 19, then M from an intermediate subset (InS) of size N3' (< N3). v A set of FD DFT vectors (FD basis) is selected. If N3 ≤ 19, log2(C(N3-1,M v -1)) bit is reported. Here, C(N3-1,M v -1) From N3-1 items, M v - This represents the number of combinations of choosing one item (combinatorial coefficient), and is also called the binomial coefficient.

[0092] The frequency domain response / distribution (frequency response) represented by a linear combination of FD DFT vectors and LC coefficients may be called an FD beam. The FD beam may also correspond to a delay profile (time response).

[0093] The PMI subband size is given by the CQI subband size / R, where R ∈ {1, 2}. In other words, R is the ratio of the CQI subband size to the PMI subband size. The number of FD DFT vectors M for a given rank v. v is, ceil(p v It is given by ×N3 / R). The number of FD DFT vectors M vThis is the same for all layers l ∈ {1, 2, 3, 4}. v This is set by the higher layer.

[0094] The multiple precoding matrices shown by PMI are L+M v It is determined by the number of vectors.

[0095] For beam indices i=0,1,...,L-1, L SD beams (SD DFT vectors) vm_1^(i),m_2^(i) are identified by q1, q2, n1, n2, i 1,1 i 1,2 This is shown by.

[0096] M v The number of FD DFT vectors is M initial ∈{-2M v +1,-2M v +2,...,0}, n 3,l =[n 3,l (0) ,...,n 3,l (M_v-1) ], n 3,l (f) It is identified by ∈{0,1,...,N3-1}.

[0097] In the FD DFT vector, the elements (FD basis) for the indices t=0,1,...,N3-1 and layers l=1,...,v of the FD basis (subband) are y t,l (f) =exp(j2πtn 3,l (f) / N3) is the M of the FD DFT vector. v The number of indices f = 0, 1, ..., M v M for -1 v The individual FD DFT vectors are, [y 0,l (f) ,y 1,l (f) ,...,y N_3-1,l (f) ] T That is the case.

[0098] W 2,lEach row represents the channel frequency response of a specific SD beam. When the SD beam has high directivity, the channel taps for each beam are limited (the power delay profile becomes sparse in the time domain). As a result, the channel frequency responses for each SD beam have high correlation (become flat in the frequency domain). In this case, the channel frequency response can be approximated by a linear combination of a small number of FD DFT vectors. For example, when M v = 2, using the FD DFT vectors f2, f q and the LC coefficients d1 0 , d2 0 , the frequency response associated with the SD beam b0 is d1 0 f2 +, d2 0 f q .

[0099] The dominant M v number of FD DFT vectors is selected. By setting M v ≪ N3, the overhead of W ~ l is much smaller than the overhead of W 2,l . All or part of the M v number of FD DFT vectors are used for approximating the frequency response of each SD beam. A bitmap is used to report only the FD DFT vectors selected for each SD beam. If the bitmap is not reported, all FD DFT vectors are selected for each SD beam. In this case, the NZCs of all FD DFT vectors for each SD beam are reported. The number of NZCs K l NZ in one layer satisfies K v ≦ K0 = ceil(β × 2LM NZ ), and the number of NZCs K v across all layers satisfies K

[0100] In the extended type 2 codebook, L, β, p vThe combination of values ​​(parameter combination) is determined by the higher-layer parameter paramCombination-r16 (parameter combination setting). L is the number of SD beams. v M is the number of FD basis vectors for rank v. v =ceil(p v This is a parameter for calculating ×N3 / R). β is a parameter for calculating the maximum number of NZCs.

[0101] In this disclosure, the terms "codebook parameter combination," "codebook parameter combination," "parameter combination," and "parameter combination setting" may be interpreted interchangeably.

[0102] The Type 2 CSI feedback on PUSCH in Rel. 16 consists of two parts. CSI Part 1 has a fixed payload size and is used to identify the number of information bits in CSI Part 2. The size of Part 2 is variable (the UCI size depends on the number of NZCs, which is unknown to the base station). The UE reports the number of NZCs in CSI Part 1, and this number determines the size of CSI Part 2. After receiving CSI Part 1, the base station recognizes the size of CSI Part 2.

[0103] In the Extended Type 2 CSI Feedback of Rel. 16, CSI Part 1 includes (if reported) the RI, the CQI, and an indicator of the total number of non-zero amplitude coefficients across multiple layers for the Extended Type 2 CSI. The fields of Part 1, (if reported) the RI, the CQI, and the indicator of the total number of non-zero amplitude coefficients across multiple layers, are encoded separately. CSI Part 2 includes the PMI for the Extended Type 2 CSI. Parts 1 and 2 are encoded separately. CSI Part 2 (PMI) includes the oversampling factor, the index of the SD basis corresponding to each SD beam, and the index M of the initial FD DFT vector (start offset) of the selected DFT window. initialIt includes at least one of the following: a selected FD basis for each layer, NZC (amplitude and phase) for each layer, a strongest coefficient indicator (SCI) for each layer, and the amplitude of the strongest coefficient for each layer / polarization.

[0104] Multiple PMI indices (PMI values, codebook indices) associated with different CSI Part 2 information are represented by the following equation F21 for the l-th layer of rank v: i1 = [i 1,1 i 1,2 i 1,5 i 1,6,1 i 1,7,1 i 1,8,1 ] (v=1) i1=[i 1,1 i 1,2 i 1,5 i 1,6,1 i 1,7,1 i 1,8,1 i 1,6,2 i 1,7,2 i 1,8,2 ] (v=2) i1=[i 1,1 i 1,2 i 1,5 i 1,6,1 i 1,7,1 i 1,8,1 i 1,6,2 i 1,7,2 i 1,8,2 i 1,6,3 i 1,7,3 i 1,8,3 ] (v=3) i1=[i 1,1 i 1,2 i 1,5 i 1,6,1 i 1,7,1 i 1,8,1 i 1,6,2 i 1,7,2 i 1,8,2 i 1,6,3 i 1,7,3 i 1,8,3 i 1,6,4 i 1,7,4 i 1,8,4 ] (v=4) (F21)

[0105] Each index is defined as follows: ◆i 1,1 : Rotation factors [q1 q2] in two-dimensional oversampling. q1 ∈ {0, 1, ..., O1-1}, q2 ∈ {0, 1, ..., O2-1}. A beam index is selected within each (SD) beam group, i 1,1 Reported / displayed by ◆i 1,2 : Multiple SD base indices corresponding to each SD beam. 1,2 ∈{0,1,...,C(N1N2,L)-1}. From N1N2 (SD) beam groups, L beam groups are selected, i 1,2 Reported / displayed by ◆i 1,5 : Codebook indicator. The index of the FD base for the selected DFT window. i 1,5 ∈{0,1,...,2M v -1}. ◆i 1,6,l : Codebook indicator. The FD basis selected for the l-th layer. If N3 ≤ 19, i 1,6,l ∈{0,1,...,C(N3-1,M v -1)-1}. If N3 > 19, i 1,6,l ∈{0,1,...,C(2M v -1,M v -1)-1}. ◆i 1,7,l : A bitmap indicator for the l-th layer. The non-zero bits in that bitmap are i 2,4,l and i 2,5,l Identify which coefficients within it will be reported. 1,7,l =[k l,0 (3) ... k l,M_v-1 (3) ], k l,f (3) =[k l,0,f (3) ... k l,M_v-1,f (3) ], k l,i,f (3) ∈{0,1}. ◆i 1,8,l : Strongest coefficient indicator for the l-th layer (maximum element k in the amplitude coefficient indicator) l,i,f (2) ). i1,8,l The strongest coefficients of layer l, identified by ∈{0,1,...,2L-1}, are i for v=1. 1,8,l =Σ i=0 i_1^* k l,i,0 (3) Given -1, for 1 < v ≤ 4, i 1,8,l =i l * It is given as follows: ◆i 2,3,l : Amplitude coefficient indicator (for both polarizations) of the coefficient (wideband) of the l-th layer. 2,3,l =[k l,0 (1) k l,1 (1) ]. ◆i 2,4,l : Amplitude coefficient indicator of the reported (subband) coefficients of the l-th layer. 2,4,l =[k l,0 (2) ... k l,M_v-1 (2) ]. ◆i 2,5,l : Phase coefficient indicator of the reported (subband) coefficients of the l-th layer. 2,5,l =[c l,0,f ... c l,M_v-1,f ].

[0106] f l * ∈{0,1,...,M v -1}, i 2,4,l Let i be the index. l * k ∈{0,1,...,2L-1} l,f_l^* (2) Let this be the index of f. l * and i l * This is the strongest coefficient for layers l=1,...,v, i, i for layer l. 2,4,l elements kl, i_l^*, f_l^* (2) Identification. Codebook index n 3,l is n 3,l (f_l^*) Regarding n 3,l (f) =(n 3,l (f)-n 3,l (f_l^*) ) is remapped to mod N3, and after remapping, n 3,l (f_l^*) = 0. The index f is f l * Regarding f=(ff l * ) mod M v It is remapped as and after remapping f l * =0 (l=1,...,v). 2,4,l i 2,5,l , and i 1,7,l The following shows the amplitude coefficient, phase coefficient, and bitmap after remapping.

[0107] W ~ l Each LC coefficient (complex coefficient) reported within is the amplitude and phase, quantized separately. ◆ Amplitude quantization polarization eigenreference amplitude is defined in the table (amplitude coefficient indicator i) in the specification. 2,3,l Mapping of elements within: Amplitude coefficient indicator element k l,p (1) from the amplitude coefficient p l,p (1) This is a 16-level quantization using mapping to p l (1) =[p l,0 (1) p l,1 (1) ] is [k l,0 (1) k l,1 (1) ], k l,p (1) It is quantized to ∈{0,...,15}. All other coefficients are defined in the table (amplitude coefficient indicator i) in the specification. 2,4,l Mapping of elements within: Amplitude coefficient indicator element k l,i,f (2) from the amplitude coefficient p l,i,f (2) This is an 8-level quantization using mapping to p l (2) =[p l,0 (2) ... pl,M_v-1 (2) ], p l,f (2) =[p l,0,f (2) ... p l,2L-1.f (2) ] is k l,f (2) =[k l,0,f (2) ... k l,2L-1.f (2) ], k l,i,f (2) It is quantized to ∈{0,...,7}. ◆Phase quantization amplitude coefficient indicator i 2,5,l Internal elements (amplitude coefficient indicator elements) [c l,0 ... c l,M_v-1 ] is reported by UE (using 4 bits). All phase coefficients are quantized using 16-PSK. Quantity φ for phase difference l,i,f = exp(j2πc l,i,f The phase coefficient in / 16) is c l,f =[c l,0,f ... c l,2L-1.f ], c l,i,fi It is quantized to ∈{0,...,15}.

[0108] The amplitude coefficient indicator element kl,floor(i_l^* / L) corresponds to the strongest coefficient of layer l. (1) =15 (maximum value), and the amplitude coefficient indicator element k l,i_l^*,0 (2) =7 (maximum value), and the phase coefficient indicator element c l,i_l^*,0 (2) =0 (minimum value). For l=1,...,v, kl,floor(i_l^* / L) (1) , k l,i_l^*,0 (2) , c l,i_l^*,0 (2) =0 is not reported.

[0109] i 1,5 and i 1,6,l This is the PMI index for reporting based on FD. Only when N3 > 19, i 1,5 It is reported.

[0110] 3000 to 2999+PCSI-RS The precoding matrix W represented by the codebook for v (=1 to 4) layer CSI reporting using (v) This is the precoding matrix W for layer l (=1 to v). l Based on the precoding matrix W. l This is expressed by the following equation F3.

[0111] Here, the beam indices i = 0, 1, ..., L-1, m1 (i) =O1n1 (i) +q1, m2 (i) =O2n2 (i) +q2, n1 (i) ∈{0,1,...,N1-1}, n2 (i) ∈{0,1,...,N2-1}. (i) n2 (i) This is the SD basis for representing the SD beam i. vm_1^(i) and m_2^(i) are the DFT vectors representing the SD beam. l,0 (1) This indicates the wideband amplitude coefficient. l,i,f (2) This indicates the subband amplitude coefficient. φ l,i,f This indicates the phase coefficient. Thus, the codebook for each layer includes the strongest coefficient for each polarization, the amplitude coefficient for each polarization, each FD beam, and each SD beam, and the phase coefficient for each polarization, each FD beam, and each SD beam.

[0112] As part of the CSI Part 2 grouping, PMI information for a given CSI report is grouped into three groups (Groups 0 and 2). This is important when CSI omissions are performed. Index i 2,4,l i 2,5,l i 1,7,l Each element reported is associated with a specific priority rule. Groups 0 and 2 follow the following: ◆ Group 0: Index i 1,1 i 1,2 i 1,8,l (l=1,...,v) ◆Group 1: Index i (if reported) 1,5 , index i (if reported)1,6,l i 1,7,l The best (top) of the v2LM v -floor(K NZ / 2) priority elements, i 2,3,l i 2,4,l The highest (top) ceil(K NZ / 2)-v priority elements, i 2,5,l The highest (top) ceil(K NZ / 2)-v priority elements (l=1,...,v) ◆Group 2: i 1,7,l The lowest (lowest) floor (K NZ / 2) priority elements, i 2,4,l The lowest (lowest) floor (K NZ / 2) priority elements, i 2,5,l The lowest (lowest) floor (K NZ ( / 2) priority elements (l=1,...,v)

[0113] In Type 1 CSI, the SD beam, represented using the SD DFT vector, is sent towards the UE. In Type 2 CSI, L SD beams are linearly combined and sent towards the UE. Each SD beam can be associated with multiple FD DFT vectors (FD beam, FD basis, frequency response). For the corresponding SD beams, the channel frequency response can be obtained by the linear combination of these FD DFT vectors. The channel frequency response corresponds to the power delay profile.

[0114] (Type 2 Port Selection Codebook) For Type 2 port selection (PS) CSI (Type 2 PS Codebook) Rel. 15, the UE sets the upper layer parameter codebookType to 'typeII-PortSelection'.

[0115] In Rel. 15 Type 2 Port Selection CSI, the UE does not need to derive the SD beam by considering the SD DFT vector as in Type 2 CSI. The base station transmits CSI-RS using K beamformed CSI-RS ports considering the set of SD beams. The UE selects / identifies the best L (≤K) CSI-RS ports for each polarization and reports their indices in W1. Rel. 15 Type 2 PS CSI supports ranks 1 and 2.

[0116] The value of d is set using the higher-level parameter portSelectionSamplingSize. d ∈ {1, 2, 3, 4} and d ≤ min (P CSI-RS ( / 2,L)

[0117] L antenna ports for each polarization i 1,1 Selected by i 1,1 ∈ {0, 1, ..., ceil (P CSI-RS The formula is (2d) - 1.

[0118] ((Enhanced Type 2 Port Selection Codebook (Rel. 16))) For Type 2PS CSI (Enhanced Type 2PS Codebook) Rel. 16, the UE sets the upper layer parameter codebookType to 'typeII-PortSelection-r16'.

[0119] The operation of the Rel. 16 Type 2 PS CSI is the same as the Rel. 16 Type 2 CSI, except for the SD beam selection. The Rel. 15 Type 2 PS CSI supports ranks 1 through 4.

[0120] For a layer l ∈ {1, 2, 3, 4}, a precoding matrix W is used for generating precoders for each subband (subband(SB)-wise). l This is expressed by the following equation F4: W l (N t ×N3) = QW1W ~ l W f,l H (F4)

[0121] Here, Q(N t ×K) represents the K SD beams used in CSI-RS beamforming. W1(K×2L) is a block diagonal matrix. ~ l (2L×M) is the LC coefficient matrix. f,l (N3×M) is a matrix consisting of M vectors (FD basis vectors), where each vector contains N3 FD basis vectors. K is set by the upper layer. L is set by the upper layer. P CSI-RS ∈{4,8,12,16,24,32}. P CSI-RS If >4, then L∈{2,3,4}.

[0122] In Rel. 15 / 16 Type 2PS CSI, each CSI-RS port #i is connected to SD beam b i It is associated with.

[0123] The extended Type 2PS CSI is similar to the Type 2 CSI of Rel. 16 in that it changes the number of FD basis vectors from N3 to M. v By reducing to (M v Compared to the Type 2PS CSI of (N3), Rel. 15, overhead is reduced.

[0124] In the expanded type 2PS codebook, L, β, p v The combination of values ​​(parameter combination) is determined by the higher-level parameter paramCombination-r16 (parameter combination setting).

[0125] ((Additional Enhanced Type 2 Port Selection Codebook (Rel. 17))) For the Rel. 17 Type 2PS CSI / codebook (further enhanced Type 2PS codebook), the UE sets the upper layer parameter codebookType to 'typeII-PortSelection-r17'.

[0126] In Rel. 17 Type 2PS CSI, each CSI-RS port #i uses an SD-FD beam pair (SD beam b) instead of an SD beam. i and FD beam f i,j It is associated with a pair (where j is the frequency index). In this example, ports 3 and 4 are associated with the same SD beam and different FD beams.

[0127] The frequency selectivity of the channel frequency response observed in UE based on an SD beam-FD beam pair can be reduced compared to the frequency selectivity of the channel frequency response observed in UE based on an SD beam by delay pre-compensation.

[0128] The main scenario in Rel. 17 Type 2PS Codebook is FDD. Channel reciprocity based on SRS measurements is not perfect (the angles of the UL and DL beams may differ, the UL and DL frequencies may differ in FDD, and the effective antenna spacing differs at those UL and DL frequencies). However, the base station can obtain / select some partial information (dominant angles and delays (SD beam and FD beam)). By using SRS measurements at the base station in addition to CSI reporting, the base station can obtain CSI for determining the DL MIMO precoder. In this case, some CSI reporting may be omitted to reduce CSI overhead.

[0129] In the additional extension type 2PS codebook, the values ​​of α, M, and β (codebook parameter combinations, parameter combinations) are determined by the higher-layer parameter paramCombination-r17 (codebook parameter setting). In the parameter combinations α, M, and β for the additional extension type 2PS codebook of Rel. 17, α is the number of selected CSI-RS ports in the PS codebook K1 = αP CSI-RSThese are the parameters for the calculation of . M is the number of FD basis vectors. β is the parameter for calculating the maximum number of NZCs. The precoding matrix shown by PMI is determined from L+M vectors, where L=K1 / 2 and K1=αP CSI-RS That is the case.

[0130] L vectors v m^(i) Based on (i=0,1,...,L-1), P CSI-RS K1 ports are selected from the available ports. Vector v m^(i) m=[m (0) ... [m (L-1) ], m (i) ∈{0,1,...,P CSI-RS Identified by / 2-1} m (i) is index i 1,2 ∈{0,1,...,C(P CSI-RS Reported / displayed by / 2,L)-1}

[0131] In the Rel. 17 additional extension type 2PS CSI, each CSI-RS port is beamformed using an SD beam and an FD beam. Each port is associated with an SD-FD beam pair.

[0132] Precoding matrix W for a given layer l l This is expressed by the following equation F5: W l (K × N³) = W¹W ~ l W f,l H (F5)

[0133] For W1 (K×2L), each matrix block consists of L columns of a K×K identity matrix. The base station transmits K beamformed CSI-RS ports. Each port is associated with an SD-FD beam pair. The UE selects L ports out of the K and reports an index indicating the selected ports to the base station as part of the PMI. In Rel. 16, each port is associated with an SD beam.

[0134] W~ l (2L x M) v The matrix consists of coupling coefficients (subband complex LC coefficients). Up to K0 NZCs are reported. The report consists of two parts: a bitmap showing the NZC locations and the quantized NZCs.

[0135] In Rel. 17 additional expansion type 2PS CSI, K l NZ =Σ i=0 k1-1 Σ f=0 M-1 k l,i,f (3) ≤K0 is the number of non-zero coefficients in layers l=1,...,v, and K NZ =Σ l=1 v K l NZ ≤ 2K0 is the total number of non-zero coefficients. If v ≤ 2 and K NZ If =K1Mv, then i for layers l=1,...,v 1,7,l The bitmap indicator for the l-th layer is not reported. In other words, if the total number of reported NZCs is equal to the maximum number of K1Mv and v ≤ 2, the reporting of the bitmap indicating the location of the NZCs is omitted. Note that in Rel. 16, the bitmap of the NZC location is always reported.

[0136] W f,l (N3×M v ) is M per layer v (M v It is a matrix consisting of 1 or 2 FD basis vectors. Each vector contains N3 FD basis vectors (FD-DFT basis vectors). The base station is W f,l You may delete it. M v If = 1, W f,l It is off, and no additional FD basis vectors are reported. v If = 2, W f,l It is on, M v An additional number of FD basis vectors are reported. vIf = 2, the window size N ∈ {2, 4} of the FD basis is set by the upper layer parameter (valueOfN). Note that in Rel. 16, W f,l This is always reported.

[0137] (JT) Joint transmission (JT) may mean simultaneous data transmission from multiple points (e.g., TRPs) to a single UE.

[0138] Rel. 17 supports non-coherent joint transmission (NCJT) from two TRPs. PDSCHs from the two TRPs may be precoded and decoded independently. Frequency resources may be non-overlapping, partially overlapping, or fully overlapping. If overlap occurs, a PDSCH from one TRP will interfere with a PDSCH from the other TRP.

[0139] In Rel. 18, support for coherent joint transmission (CJT, mTRP CJT) using up to four TRPs is being considered. Data from the four TRPs may be coherently precoded and transmitted to the UE over the same time-frequency resources. For example, the same precoding matrix may be used for channels from the four TRPs. "Coherent" may mean that there is a constant relationship between the phases of multiple received signals. Using 4TRP joint precoding, signal quality may be improved and there may be no interference between the four TRPs. The data may only be subject to interference outside the four TRPs.

[0140] (NCJT CSI / Type 1 Codebook) In Rel. 17, the scenario to which NCJT CSI reporting is applicable is a single DCI-based MTRP NCJT with a Type 1 single-panel codebook. For NCJT CSI measurement, two CMR groups can be configured within a single CSI-ReportConfig, each with a channel measurement resource (CMR) from one TRP. One CSI reporting mode can be configured from two modes.

[0141] RRC signaling enables CSI-ReportConfig for Rel. 17 non-coherent joint transmission (NCJT) CSI to configure the CMR and the CSI reporting mode (csi-ReportMode).

[0142] K s Two CMR groups with K1 + K2 CMRs are set to UE. 2 ≤ K s ≤ 8. K s Each CMR corresponds to an NZP-CSI-RS resource set for channel measurement. K1 and K2 are the number of CMRs in two CMR groups, respectively. N (N sets) of CMR pairs (resource pairs) are set up by the upper layer through selection from all possible pairs. N=1, K s =2 is supported. N max Support for =2 is an optional feature of UE. S,max Support for =X is an optional feature of the UE. Each CMR can contain up to 32 CSI-RS ports, depending on the UE's capabilities. Each CMR pair is associated with one CRI value.

[0143] The bitmap generated by RRC signaling shows the N (N=1,2) CMR pairs actually used for NCJT measurement by indicating one CMR from each CMR group. The UE measures a single TRP CSI for TRP1 and a single TRP CSI for TRP2 using the CMRs in two CMR groups, and measures the NCJT CSI using the N CMR pairs.

[0144] The UE selects one or more CSIs to report based on the mode (CSI reporting mode) set by csi-ReportMode. csi-ReportMode indicates one of two modes (NCJT CSI modes) below: ◆ Mode 1 The UE may be configured to report X CSIs associated with a single TRP measurement hypothesis and one CSI associated with an NCJT measurement hypothesis. X=0,1,2. If X=2, two CSIs are associated with two different single TRP measurement hypothesis with multiple CMRs from different multiple CMR groups. Support for X=1,2 is an optional feature of the UE for a UE that supports option 1. ◆ Mode 2 The UE is configured to report one CSI associated with the best of the NCJT and single TRP measurement hypothesis.

[0145] In Mode 1, the UE reports a total of X+1 CSIs, including X (X=0,1,2) single TRP CSIs and one NCJT CSI. In Mode 2, the UE reports one best CSI (one CSI) from all single TRP CSIs and one NCJT CSI.

[0146] Within a single CSI report, up to two single TRP CSIs and one NCJT CSI may be reported (Mode 1 with X=2). An NCJT CSI includes one CRI, two RIs (with one joint RI index), two PMIs, two LIs, and one CQI (four layers or less). A single TRP CSI is the same as an existing CSI and includes one CRI, one RI / PMI / LI, and one or two CQIs (eight layers or less, one CQI per CW).

[0147] New mapping sequences (tables) for multiple fields within a single CSI report are defined for the following cases: ◆ Mapping sequence for wideband CSI for mode 1 with X=0. Wideband CSI is supported only for mode 1 with X=0, i.e., NCJT CSI. ◆ Mapping sequence for CSI Part 1 for modes 1 and 2. ◆ Mapping sequence for CSI Part 2 wideband for modes 1 and 2. ◆ Mapping sequence for CSI Part 2 subbands for modes 1 and 2.

[0148] (CJT CSI / Type 2 Codebook) In the ideal case where four TRPs are collated (considered to be in the same position), joint estimation of the aggregated channel matrix H can be performed, and the joint precoding matrix V can be fed back. However, the large-scale path loss of the four paths can differ significantly. The joint precoding matrix V based on the constant module codebook is not accurate. In this case, the feedback per TRP and the coefficients between TRPs (inter-TRP) can be aligned with the current NR Type 2 codebook.

[0149] For CJT of up to four TRPs in FR1, the selection of the four TRPs may be semi-static. Therefore, the selection and the setting of the four CMRs (four CSI-RS resources) for channel measurement may also be semi-static. Dynamic instruction of the four TRPs from the list of CSI-RS resources is also possible, but unlikely.

[0150] The path loss from the four TRPs to the UE is different. Therefore, it is insufficient to report only one aggregated CSI representing the joint channel matrix.

[0151] Considering the fallback operation to NCJT (i.e., single TRP), a CSI for each TRP (i.e., a single TRP CSI like the NCJT CSI in Rel. 17) is also conceivable.

[0152] Assuming an ideal backhaul, synchronization, and the same number of antenna ports across multiple TRPs, CSI acquisition for coherent joint transmission (CJT) for FR1 and up to four TRPs is being considered. For CJT multi-TRPs for FDDs, improvements to the extended (Rel. 16) Type 2 codebook and the additional extended (Rel. 17) Type 2 PS codebook are being considered.

[0153] W1 (matrix representing the SD DFT vector) for each TRP / W f The matrix (showing the FD DFT vectors) may be the same or different. W for each TRP l (NZC) may be different. W1 / W for each TRP f / W l These may be selected jointly or individually. W1 / W f / W l For the design, it is preferable to have different scenarios with different options. φ This may be reported as individual content, W lThese may be reported internally. The policies used relate to deployment scenarios (e.g., intra-site multi-TRP or inter-site multi-TRP).

[0154] For example, the precoding matrix for 4-TRP CJT CSI (codebook) is W1 / W for each TRP. f / W l It may be represented by . W1 for each TRP may be the same, different, jointly selected, or individually selected. W for each TRP l These may be different, jointly selected, or individually selected. W for each TRP f They may be the same, different, jointly selected, or individually selected.

[0155] There are two codebook mode settings for FD basis selection. In mode 1, to show the FD basis offset for the j-th selected CSI-RS resource for j=2,...,N, i 1,9 A report is required. In mode 2, i 1,9 Reporting is not required. All CSI-RS resources have the same FD basis selection.

[0156] ◆Mode 1 is a basis selection of SD / FD per TRP / TRP group. It allows independent FD basis selections across N TRPs / TRP groups. For example, its codebook structure is given by the following equation G1, where N is the number of TRPs or TRP groups.

[0157] ◆Mode 2 consists of SD basis selection per TRP / TRP group (port group or resource) and joint / common FD basis selection (spanning N TRPs / TRP groups). For example, its codebook structure is given by the following equation G2, where N is the number of TRPs or TRP groups.

[0158] In these two modes, detailed design elements such as parameter combinations, basis selection, TRP (group) selection, reference amplitude, and W2 quantization scheme may be common to all.

[0159] For the enhanced Type II codebook for CJT (Type II CSI for CJT of Rel. 18), the UE may set the higher-level parameter codebookType to 'typeII-CJT-r18'. For the further enhanced Type II port selection codebook for CJT (Type II PS CSI for CJT of Rel. 18), the UE may set the higher-level parameter codebookType to 'typeII-CJT-PortSelection-r18'.

[0160] UE is N within the resource set for channel measurement. TRP ∈{1,2,3,4} CSI-RS resources can be configured.

[0161] In the extended type 2 codebook for CJT, the upper layer parameter paramCombination-CJT-L-r18 is used to define {L1,...,L N_TRP The value of N L A set of ∈{1,2,4} combinations is established. L The value is set by the higher-level parameter numberOfSDCombinations.

[0162] In the additional extension type 2PS codebook for CJT, the upper layer parameter paramCombination-CJT-PS-alpha-r18 is used to define {α1,...,α N_TRP The value of N L A set of ∈{1,2,4} combinations is established. L The value is set by the higher-level parameter numberOfSDCombinations-PS.

[0163] The UE may have the upper layer parameter restrictedCMR-Selection set. If restrictedCMR-Selection is set, the number of CSI-RS resources to be selected N is N TRP Therefore, if not, UE is 1 ≤ N ≤ N TRP We expect to select N CSI-RS resources, and the selection is N TRP It is reported using a bitmap of bits.

[0164] In SD beam selection / reporting, the SD beam selection / reporting method for each CSI-RS resource is applied.

[0165] In the extended type 2 codebook for CJT, the precoding matrix shown by PMI is Σ j=1 N L σ_j +M v It is determined from the number of vectors. Here, {σ1,...,σ N} is 1≦σ1<…<σ N ≤N TRP This is an index of N CSI-RS resources selected in ascending order. TRP This could be the number of CSI-RS resources configured for CSI reporting, or the number of TRPs for CJT. σ_1 ,...,L σ_N} is {L1,...,L N_TRP This is the corresponding value from the selected combination of}.

[0166] j=1,...,N, i=0,1,...,L σ_j For -1, L corresponds to the j-th selected CSI-RS resource. σ_j The vectors vm_1, f^(i), m_2, f^(i) are i 1,1 i 1,2 It is displayed / reported by i. 1,1 i 1,2 This is given by the following equation G3: i 1,1 =[i 1,1,1 ... i 1,1,N ] i 1,1,j =[q 1,jq 2,j ] q 1,j ∈{0,1,...,O1-1} q 2,j ∈{0,1,...,O2-1} i 1,2 =[i 1,2,1 ... i 1,2,N ] i 1,2,j ∈{0,1,...,C(N1N2,L σ_j )-1} (G3)

[0167] In the additional extension type 2PS codebook for CJT, the precoding matrix shown by PMI is Σ j=1 N L σ_j It is determined from +M vectors. Here, {σ1,...,σ N} is 1≦σ1<…<σ N ≤N TRP This is an index of N CSI-RS resources selected in ascending order. σ_j =K 1,σ_j / 2, K 1,σ_j =α σ_j *P CSI-RS It is. {α σ_1 ,...,α σ_N} is {α1,...,α N_TRP This is the corresponding value from the selected combination of}.

[0168] j=1,...,N, i=0,1,...,L σ_j -1 vs L σ_j individual vectors v m_j^(i) Based on this, the P of the j-th selected CSI-RS resource CSI-RS From these ports, K 1,σ_j A number of ports are selected, i 1,2 It is displayed / reported by i. 1,2 This is given by the following equation G4: i 1,2 =[i 1,2,1 ... i 1,2,N ] i 1,2,j ∈{0,1,...,C(P CSI-RS ,L σ_j )-1} (G4)

[0169] In this disclosure, the following terms may be interpreted interchangeably: CJT Codebook, CJT Type 2 Codebook, CJT Extended Type 2 Codebook, Rel. 18 CJT Type 2 Codebook, typeII-CJT-r18, CJT Additional Extended Type 2 PS Codebook, Rel. 18 CJT Type 2 PS Codebook, typeII-CJT-PortSelection-r18'.

[0170] (Doppler CSI / Type 2 Codebook) It is being considered to extend / improve the capabilities of CSI reporting for fast / medium-speed moving UEs by utilizing time-domain correlation / Doppler-domain (DD) information. For example, it is being considered to improve the extended (Rel. 16) Type 2 codebook and the additional extended (Rel. 17) Type 2 PS codebook without changing the spatial domain basis and frequency domain basis, and to report time-domain channel characteristics (time-domain correlation profiles) measured via tracking RS (TRS) from the UE.

[0171] The channel coherent time (CCT) depends on the maximum Doppler shift. Channel coherent time is the time during which the measured channel characteristics are available, or the time until the measured channel characteristics become unavailable (channel aging). The maximum Doppler shift is estimated by the relative velocity between the transmitter and receiver. c is 1 / Δf max It is approximated by Δf max =v / λ. As the UE's movement speed increases, the channel coherence time decreases. For example, at a carrier frequency of 4.5 GHz, when the movement speed exceeds approximately 25 km / h, the channel coherence time falls below 10 ms. The problem then becomes how to deal with such high movement speeds and short channel coherence times.

[0172] TRS is supported to track Doppler shift. However, TRS has the following problems: ◆ The number of ports per CSI-RS resource set is limited to one. Each CSI-RS resource uses a single port. ◆ The configurable period is 10ms or longer. ◆ CSI reporting for TRS is not assumed. There is no reporting setting for P-TRS. Reporting can be set, but the report quantity can only be set to none ('none'). A maximum of 16 CSI-RS resources are used per CSI-RS resource set.

[0173] TRS (Time-Resistance Systems) are deployed in time-domain and frequency-domain resources. To measure the effects of Doppler shift, multiple time-domain RSs are required within a specific frequency-domain resource.

[0174] CMR can be used to measure the effects of Doppler shift. However, the RS used for measurement depends on the UE implementation.

[0175] Information regarding Doppler shift is not supported in the CSI report. Information for determining W=W1W2 is reported by the UE via the CSI Codebook (PMI), where W1 is the wideband characteristic and represents the spatial beam, and W2 is the subband characteristic and represents the amplitude / phase coefficient for each spatial beam.

[0176] Regarding the measurement of Doppler shift, two cases are possible: Case 1, where the UE performs the measurement based on CSI-RS, and Case 2, where the base station performs the measurement based on SRS. Regarding the determination of the effect of Doppler shift, three cases are possible: Case 1-1, where the UE makes the determination based on the CSI-RS measurement results; Case 1-2, where the base station makes the determination based on the CSI-RS measurement results reported by the UE; and Case 2-1, where the base station makes the determination based on the SRS measurement results.

[0177] CSI-RS measurement windows and CSI reporting windows are being considered. Within a CSI-RS measurement window, one or more CSI-RS occasions may be measured. The reported CSI may be associated with a CSI reporting window.

[0178] Assuming a CSI report within slot n, the length of the Doppler domain (DD) / time domain (TD) basis vector (DFT basis vector) (number of basis vectors for DD / TD) may be N4. Slot [k, k+W meas Within the CSI measurement window of -1], one or more CSI occasions for calculating the CSI report may be measured. Here, k may be a slot index, and W meas This may be the measurement window length (number of slots). CSI occasions may be set within CSI-ReportConfig. Slots [l, l+W CSI The CSI reporting window of -1] may be associated with the CSI report in slot n, where l may be the slot index, and W CSI This may be the reporting window length (number of slots). The location of the CSI reference resource is n ref It may also be expressed as follows.

[0179] CSI reporting window duration (W) CSI = dN4. d and N4 are determined by the CMR settings. The starting point of the CSI reporting window is slot l. l = (nN CSI,ref ) may also be the case. l = (n + δ) may also be the case. δ = {0, 2} may also be the case, or δ = {0, 1, 2} may also be the case.

[0180] The d slot may also represent the duration in DD units.

[0181] If UE-side prediction is assumed, the UE is supported in predicting the CSI / channel after slot l, and the base station sets the position of slot l (from multiple candidate values) via upper-layer signaling. The multiple candidates for the position of slot l are the existing CSI reference resource positions (nNCSI,ref This includes (nN) and (n+δ), where δ > 0. This includes existing CSI reference resources in existing operations, i.e., (nN CSI,ref ) will be reused / repurposed to indicate the location of the last CSI-RS occasion used in the CSI report.

[0182] An additional value of 2 is supported for the parameter δ.

[0183] N4 is configured by the base station via upper-layer signaling.

[0184] In N4=1, the DD basis may be identical (identity, identity). DD compression is not required. In this case, the codebook structure may be, for example, the following equation H1.

[0185] In N4 > 1, the Doppler domain orthogonal DFT basis may be selected in common for all SD / FD basis. In this case, the codebook structure may be, for example, the following equation H2.

[0186] Only Q > 1, indicating the number of selected Doppler domain (DD) basis vectors, is acceptable. The detailed design of the SD / FD basis, including the associated UCI parameters, follows existing specifications.

[0187] For the enhanced Type II codebook for predicted PMI (Rel. 18 Type II CSI for predicted PMI), the UE may set the upper layer parameter codebookType to 'typeII-Doppler-r18'. For the further enhanced Type II port selection codebook for predicted PMI (Rel. 18 Type II PS CSI for predicted PMI), the UE may set the upper layer parameter codebookType to 'typeII-Doppler-PortSelection-r18'.

[0188] In this disclosure, the following terms may be interpreted interchangeably: Doppler codebook, Doppler type 2 codebook, extended type 2 codebook for predictive PMI, Rel. 18 type 2 CSI codebook for predictive PMI, typeII-Doppler-r18, additional extended type 2 PS codebook for predictive PMI, Rel. 18 type 2 PS codebook for predictive PMI, typeII-Doppler-PortSelection-r18.

[0189] (TDCP Reporting) It is being considered that UEs (User Engineers) should report time-domain channel properties (TDCP).

[0190] The report quantity set in 'tdcp' (upper layer parameter reportQuantity), the upper layer parameter Y≧1, and the delay {D1,...,D Y For a CSI-ReportConfig accompanied by}, the TDCP amplitude k corresponds to Y delays. TDCP =[k1 ... k Y ] is reported. Here, k i The range is ∈{0,...,15}. For i=1,...,Y, the corresponding amplitude value is 1-a i It is obtained from k. i from a i The mapping to is defined in the specification.

[0191] For Y > 1, if the upper layer parameter phase is set, then the TDCP phase c TDCP =[c1 ... c Y ] is reported. Here, c i The range is ∈{0,...,15}. The corresponding phase value is exp(j2πc i It is given by ( / 16).

[0192] (CSI-RS port) In Rel. 15, CSI-RS is used as a DL RS for at least one of channel state information (CSI) acquisition, beam management (BM), beam failure recovery (BFR), and fine tracking of time and frequency. CSI-RS supports 1, 2, 4, 8, 12, 16, 24, and 32 ports (antenna ports, CSI-RS ports). CSI-RS supports periodic, semi-persistent, and aperiodic transmissions. The frequency density of the CSI-RS is configurable to adjust overhead and CSI estimation accuracy.

[0193] Figure 1 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 location (k bar, l bar)), code division multiplexing (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.

[0194] The CDM group includes no CDM (N / A), FD-CDM2, CDM4, and CDM8. FD-CDM2 multiplexes two-port CSI-RS at the same time and frequency by multiplying a 2-length frequency domain (FD)-orthogonal cover code (OCC) in RE units (FD2). CDM4 multiplexes four-port CSI-RS at the same time and frequency by multiplying a 2-length FD-OCC and a 2-length time domain (TD)-OCC in RE units and symbol units (FD2TD2). CDM8 multiplexes eight-port CSI-RS at the same time and frequency by multiplying a 2-length FD-OCC and a 4-length TD-OCC in RE units and symbol units (FD2TD4).

[0195] (More than 32 CSI-RS ports) The maximum number of CSI-RS ports, 32, is greater than the maximum number of layers, 8, allowing the UE to measure the status of many channels and improve measurement accuracy.

[0196] Since Rel. 19, massive MIMO using more than 32 ports has been considered.

[0197] A CSI supporting up to 128 CSI-RS ports is being considered, targeting FR1. Specifically, the following items are being considered: ◆ Item 2a: An improvement to the Type 1 codebook that supports up to 128 CSI-RS ports in total across all resources, based on an extension of the existing codebook and assuming existing CSI-RS resources (with up to 32 CSI-RS ports per resource). ◆ Item 2b: An improvement to the Type 2 codebook that supports up to 128 CSI-RS ports in total across all resources, based on an extension of the existing codebook and assuming existing CSI-RS resources (with up to 32 CSI-RS ports per resource), without changing any codebook parameters other than introducing an additional value for the codebook parameter for the number of ports. ◆Item 2c: Expansion of CRI-based CSI reporting (reporting of CQI / PMI / RI calculated for each CRI for one or more CRIs) for hybrid beamforming, supporting up to 128 CSI-RS ports in total across all resources, using up to 32 CSI-RS ports per resource, without requiring a new codebook design.

[0198] <Number of New Ports and New (N1,N2)> Regarding items 2a and 2b, in the extended CB for the number of new ports (more than 32), the following combinations (Figure 2) are being considered to be supported for the total number of CSI-RS ports P across aggregated multiple resources and (N1,N2): ◆P=48, (N1,N2)=(8,3) ◆P=48, (N1,N2)=(6,4) ◆P=64, (N1,N2)=(16,2) ◆P=64, (N1,N2)=(8,4) ◆P=128, (N1,N2)=(16,4) ◆P=128, (N1,N2)=(8,8)

[0199] The extended CB may be an extended CB based on a type 1 CB, an extended CB based on (Rel. 16) an extended type 2 CB, or an extended CB based on (Rel. 18) a type 2 Doppler CB.

[0200] In the expanded port selection (PS) CB, the number of new ports P CSI-RS Support for ={48,64} is being considered. The extended PS CB may also be an additional extended type 2 PS CB (Rel. 17).

[0201] <Multi-CRI Reporting> Regarding item 2c, multi-CRI reporting is being considered to use an extended CB based on at least one of type 1 CBs and type 2 CBs.

[0202] The number of CMRs that will actually be used is K, relative to the set number of CMRs. S The supported values ​​may differ between extended CBs based on type 1 CBs and extended CBs based on type 2 CBs.

[0203] In CRI-based CSI extension / improvement for more than 32 CSI-RS ports, K S The value and the maximum number of ports per NZP CSI-RS resource (CMR) may be based on at least one of the following combinations: ◆K S For 2, 3, and 4, the maximum number of ports per resource is 32. S For 5, 6, 7, and 8, the maximum number of ports per resource is 16.

[0204] In this disclosure, multi-CRI reporting, multi-CRI based reporting, CSI reporting based on setting the reporting volume for multi-CRI, extended CRI for multi-CRI, and a single CSI report including multiple CRIs may be interpreted as mutually exclusive.

[0205] (Analysis) Support for CSI-RS codebook schemes with more than 32 ports is being considered for future wireless communication systems (e.g., Rel. 19 and beyond).

[0206] When a larger number of ports are deployed / implemented, there are concerns about increased overhead in the frequency domain.

[0207] To reduce the load on UE / base stations, a reduction in the density of CSI-RS in the frequency domain is being considered.

[0208] However, densities lower than those specified in existing tables (e.g., Figure 1) may impair the accuracy of subband CSI.

[0209] Reducing density in the frequency domain may not be suitable for some codebook types that require reporting at a fine subband reporting granularity.

[0210] Therefore, density reduction in the frequency domain may be applied to specific codebook types.

[0211] To reduce density in the frequency domain, the following issues A through D are being considered: ◆ Issue A: Support for new CSI-RS locations for reducing density in the frequency domain. ◆ Issue B: Codebook schemes to be applied to introduce density reduction in the frequency domain. ◆ Issue C: Methods for sharing CSI-RS frequency locations between base stations and UEs. ◆ Issue D: Limitations and setting methods for density reduction in the frequency domain.

[0212] Therefore, the present inventors have conceived of the following embodiments. According to one aspect of this disclosure, the frequency density of CSI-RS can be suitably reduced.

[0213] 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.

[0214] (Various substitutions) In this disclosure, words enclosed in parentheses () may indicate an explanation of the preceding word (e.g., an explanation of spelling), a paraphrase, a specific example, or supplementary explanation. Also, in this disclosure, words enclosed in square brackets [] may be interpreted as part of the overall meaning of the text, or they may be interpreted as being excluded (ignored). Note that parentheses () and square brackets [] may be used for purposes / meanings other than those described above.

[0215] In this disclosure, "A / B" and "at least one of A and B" may be interpreted as mutually exclusive. In this disclosure, "A / B / C" may mean "at least one of A, B, and C".

[0216] In this disclosure, terms such as notice, activate, deactivate, indicate (or specify), select, configure, update, and determine may be interpreted interchangeably. In this disclosure, terms such as support, control, controllable, operate, and capable of operating may be interpreted interchangeably.

[0217] In this disclosure, Radio Resource Control (RRC), RRC parameters, RRC messages, higher-layer parameters, fields, Information Elements (IE), settings, etc., may be interpreted interchangeably. In this disclosure, Medium Access Control elements (MAC Control Elements (CE)), update commands, activation / deactivation commands, etc., may be interpreted interchangeably.

[0218] In this disclosure, the upper layer signaling may be any or a combination thereof, such as Radio Resource Control (RRC) signaling, Medium Access Control (MAC) signaling, broadcast information, and other messages (e.g., messages from the core network, such as positioning protocol messages (e.g., NR Positioning Protocol A (NRPPPa) / LTE Positioning Protocol (LPP)) messages).

[0219] In this disclosure, MAC signaling may include, for example, MAC Control Elements (MAC CEs) and MAC Protocol Data Units (PDUs). Broadcast information may include, for example, Master Information Blocks (MIBs), System Information Blocks (SIBs), Remaining Minimum System Information (RMSIs), and Other System Information (OSIs).

[0220] In this disclosure, physical layer signaling may include, for example, Downlink Control Information (DCI) and Uplink Control Information (UCI).

[0221] In this disclosure, ceil(x), ceiling function, and ceiling function may be interpreted as interchangeable. In this disclosure, floor(x), floor function, and floor function may be interpreted as interchangeable. In this disclosure, sqrt(x), square root of x, and root x may be interpreted as interchangeable. In this disclosure, x mod y, mod(x, y), mod function, and modulo operation may be interpreted as interchangeable. In this disclosure, Σ i=M M＋N－1 f(i), Σ i=M M+N-1 f i f(i) or f over i = M, M+1, ..., M+N-1 i The sum of f(M) + f(M+1) + ... + f(M+N-1), f M +f M＋1 +...+f M＋N－1 , can be read interchangeably. C(n,k) is the number of combinations of choosing k values ​​from n values ​​(combinatorial coefficient), binomial coefficients, n Ck , C n k , may be interpreted as mutually exclusive. In this disclosure, x / / y and floor(x / y) may be interpreted as mutually exclusive.

[0222] In this disclosure, A b The notations A_b, Ab, and A with a b placed to the lower right may be interpreted as interchangeable. In this disclosure, A c The notation A^c, with a c superscripted above A, may be interpreted as interchangeable. In this disclosure, A b c The notation A_b^c, where b is placed to the lower right of A and c is placed to the upper right of A, may be interpreted as being interchangeable. In this disclosure, x ～ x may be represented by placing a tilde above it, or it may be called x tilde. In this disclosure, x － x may be represented by placing a minus sign above it, or it may be called an x-bar. In this disclosure, x ＾ This can also be represented by placing a ^ above x, or it may be called an x-hat.

[0223] In this disclosure, FR may be at least one of FR1, FR2, FR2-1, FR2-2, FR3, subterahertz, and terahertz. In this disclosure, the frequency range corresponding to FR1 may be 410–7125 MHz. In this disclosure, FR2 may include FR2-1 and FR2-2, the frequency range corresponding to FR2-1 may be 24250–52600 MHz, and the frequency range corresponding to FR2-1 may be 52600–71000 MHz.

[0224] In this disclosure, the following abbreviations may be used: ◆FDM: frequency division multiplexing ◆TDM: time division multiplexing

[0225] In this disclosure, the terms "indicate," "report," and "select" may be interpreted as interchangeable.

[0226] In this disclosure, the number of expanded ports, the number of expanded CSI-RS ports, and new P CSI-RS The new number of ports, the number of ports exceeding 32, and 48 / 64 / 72 / 96 / 128 may be interpreted interchangeably. In this disclosure, the existing number of ports, the existing number of CSI-RS ports, and the existing P CSI-RS The phrases "32 or fewer ports" can be interpreted interchangeably.

[0227] In this disclosure, (N1,N2), (N1,N2) setting, (N1,N2) value, n1-n2, antenna setting, antenna arrangement, antenna position, gNB antenna, 2D antenna, 2D arrangement, 2D position, setting of 2D arrangement, setting relating to the size of the 2D matrix for antenna arrangement / beam selection may be interpreted as one another.

[0228] In this disclosure, existing (N1, N2), (N1, N2) for existing number of ports, setting of two-dimensional antenna arrangement for 32 or fewer ports, and first setting for two-dimensional arrangement of multiple antennas for 32 or fewer ports may be read interchangeably. In this disclosure, new (N1, N2), (N1, N2) for expanded number of ports, setting of two-dimensional antenna arrangement for more than 32 ports, and second setting for two-dimensional arrangement of multiple antennas for more than 32 ports may be read interchangeably. In this disclosure, new (N g1 ,N g2 The third setting for the two-dimensional arrangement of multiple groups of antennas based on (N1,N2) for the number of expanded ports, the setting for the two-dimensional panel arrangement for more than 32 ports, and the setting for the two-dimensional arrangement of multiple groups of antennas associated with each of the multiple CSI-RS resources may be interpreted as being interchangeable.

[0229] In this disclosure, the terms xport CSI-RS resource, CSI-RS resource associated with xport, and CSI-RS resource using xport may be interpreted interchangeably.

[0230] In this disclosure, CSI-RS resource, existing port CSI-RS resource, CSI-RS, CMR, port group, group of 32 or fewer ports, port group, group of 32 or fewer ports associated with one CSI-RS resource, CSI-RS resource associated with a group of 32 or fewer ports, CSI-RS resource associated with a group of N1N2O1O2 SD beams based on existing (N1,N2), CSI-RS resource associated with a group of N1N2O1O2 gNB antennas based on existing (N1,N2), existing N1N2O1O2 antennas, and existing N1N2O1O2 SD beams may be interpreted as one another.

[0231] In this disclosure, groups, sets, blocks, and pools of 32 or fewer ports for supporting an expanded number of ports may be interpreted as interchangeable. In this disclosure, groups, sets, blocks, and pools of N1N2O1O2 SD beams based on existing (N1,N2) may be interpreted as interchangeable. In this disclosure, groups, sets, blocks, pools, and panels of N1N2O1O2 gNB antennas based on existing (N1,N2) may be interpreted as interchangeable.

[0232] In this disclosure, CSI-RS resources for expanded port count, new port CSI-RS resources, expanded port CSI-RS resources, expanded CSI-RS, expanded CMR, new group, multiple port groups, CSI-RS resources associated with more than 32 ports, CSI-RS resources associated with a group of N1N2O1O2 SD beams based on new (N1,N2), CSI-RS resources associated with a group of N1N2O1O2 gNB antennas based on new (N1,N2), new N1N2O1O2 antennas, and new N1N2O1O2 SD beams may be interpreted as one another.

[0233] In this disclosure, (N g1 ,N g2), ng1-ng2, panel settings, gNB panel settings, CSI-RS resource / port group / panel / antenna group arrangement / location / 2D arrangement may be interpreted as mutually interchangeable. In this disclosure, N g ng, panel settings, gNB panel settings, CSI-RS resource / port group / panel / antenna group may be interpreted as each other.

[0234] In this disclosure, the terms "new N1N2" and "new N1×N2 based on (N1,N2)" may be interpreted interchangeably. In this disclosure, the terms "existing N1N2" and "existing N1×N2 based on (N1,N2)" may be interpreted interchangeably.

[0235] In this disclosure, novel N1N2O1O2 and novel (N1,N2) based N1O1×N2O2 may be interpreted as mutually exclusive. In this disclosure, existing N1N2O1O2 and existing (N1,N2) based N1O1×N2O2 may be interpreted as mutually exclusive.

[0236] In this disclosure, the positions within a new (N1,N2), the positions of gNB antennas based on the new (N1,N2), and the positions within two gNB antennas based on the new (N1,N2) may be interpreted as mutually exclusive. In this disclosure, the positions within an existing (N1,N2), the positions of gNB antennas based on the existing (N1,N2), the positions within two gNB antennas based on the existing (N1,N2), and the positions within two existing gNB antennas may be interpreted as mutually exclusive.

[0237] In this disclosure, the terms "new (N1,N2)-based SD beam" and "SD beams within two N1N2O1O2 SD beams based on the new (N1,N2)" may be interpreted interchangeably. In this disclosure, the terms "position within existing (N1,N2)", "SD beam based on existing (N1,N2)", and "SD beams within two N1N2O1O2 SD beams based on existing (N1,N2)" may be interpreted interchangeably.

[0238] In this disclosure, (i 1,1 ,i 1,2The index indicating the beam, the first index, the third index, and the two-dimensional index may be interpreted as being interchangeable. In this disclosure, i 1,4 The index indicating the CSI-RS resource corresponding to the beam, the second index, the one-dimensional index, and the two-dimensional index may be interpreted as being interchangeable.

[0239] In this disclosure, one or more channel measurement resources associated with more than 32 ports (extended port count), one or more CMRs, one or more new port CSI-RS resources, multiple existing port CSI-RS resources, one or more new groups, and corresponding resource sets for channel measurement may be interpreted as one another. In this disclosure, multiple channel measurement resources, one or more CMRs, multiple existing port CSI-RS resources, and corresponding resource sets for channel measurement may be interpreted as one another. In this disclosure, one or more IMRs, one or more CSI-RS / CSI-IM resources for interference measurement, and corresponding resource sets for interference measurement may be interpreted as one another.

[0240] In this disclosure, the channel measurement occasion and at least one CSI-RS transmission occasion may be interchangeable. In this disclosure, the interference measurement occasion and the CSI-RS / CSI-IM occasion may be interchangeable.

[0241] In this disclosure, [First / Second] CSI-RS and [First / Second] CSI-RS Resource may be interpreted as equivalent to each other.

[0242] (Wireless Communication Method) <Embodiment A> It may be difficult to share the same CSI-RS resources between existing (e.g., Rel. 15-18, up to 32 ports) CSI-RS and new (e.g., Rel. 19, more than 32 ports) CSI-RS. Since existing UEs cannot despread new TD-OCC / FD-OCC, the base station needs to set up separate sets of CSI-RS resources for existing (e.g., Rel. 15-18) UEs and new (e.g., Rel. 19) UEs. This causes CSI-RS overhead. Attempting to reduce CSI-RS overhead may limit performance improvements for more than 32 CSI-RS ports.

[0243] More than 32 ports may not be introduced for the same CSI-RS resource (time and frequency resources), and multiple different CSI-RS resources may use different CSI-RS ports. Multiple CSI-RS resources may be aggregated for a new UE.

[0244] For example, two CSI-RS resources may be configured, with the first CSI-RS resource associated with CSI-RS ports #0 to #31 and the second CSI-RS resource associated with CSI-RS ports #32 to #63. In this case, it becomes easier to share CSI-RS resources between existing UEs and new UEs. For example, only the first CSI-RS resource may be configured for the existing UE, while both the first and second CSI-RS resources may be configured for the new UE.

[0245] According to this embodiment, by changing the definition of the CSI-RS port mapping, it is possible to define more than 32 CSI-RS ports, thereby minimizing the impact on the specifications.

[0246] As shown in the example in Figure 3, CSI-RS resource #1 and CSI-RS resource #2 may be configured to be FDM'd, with CSI-RS resource #1 associated with CSI-RS ports #0 to #31 and CSI-RS resource #2 associated with CSI-RS ports #32 to #63.

[0247] As shown in the example in Figure 4, CSI-RS resource #1 and CSI-RS resource #2 to be TDM are configured, with CSI-RS resource #1 associated with CSI-RS ports #0 to #31 and CSI-RS resource #2 associated with CSI-RS ports #32 to #63.

[0248] The size of the time resource for each CSI-RS resource may be slot / subslot / subframe. The size of the frequency resource for each CSI-RS resource is PRB / 2 N It may also be a series of PRBs (N=-2,-1,1,2,...).

[0249] A method for mapping more than 32 CSI-RS ports across multiple CSI-RS resources may follow at least one of the following embodiments A-X.

[0250] <<Embodiment A-1>> If the UE is configured with a higher-level parameter that enables more than 32 CSI-RS ports, and the UE is configured with x CSI-RS ports and y CSI-RS resources, the UE may map the CSI-RS ports according to at least one of the following rules. x may be 32 or less. - The first resource among the y CSI-RS resources (or CSI-RS resource sets) is mapped from CSI-RS port #0 to #x-1. - The second resource among the y CSI-RS resources (or CSI-RS resource sets) is mapped from CSI-RS port #x to #2x-1. - The third resource among the y CSI-RS resources (or CSI-RS resource sets) is mapped from CSI-RS port #2x to #3x-1. - The i-th resource in y CSI-RS resources (or CSI-RS resource sets) is mapped from CSI-RS port #(i-1)x to #ix-1. The i-th resource may be a CSI-RS resource corresponding to the i-th time resource (e.g., a slot) or a CSI-RS resource corresponding to the i-th frequency resource (e.g., a PRB).

[0251] <<Embodiment A-2>> Multiple CSI-RS resources to be aggregated may be associated with more than 32 CSI-RS ports. Each CSI-RS resource may be associated with 32 or fewer CSI-RS ports. Multiple CSI-RS resources for aggregation may be subject to at least one of the following options: - Option 1: The number of CSI-RS resources for aggregation is M. For example, M may be 2. - Option 2: The number of ports associated with each CSI-RS resource for aggregation is fixed at N or greater than O (greater than or equal to O). For example, N may be 32. For example, O may be 16. - Option 3: Multiple CSI-RS resources for aggregation are configured within the same CSI-RS resource set or CSI-RS resource group. - Option 4: Multiple CSI-RS resources for aggregation have at least one identical setting of density, number of ports, time operation setting, frequency resource placement, time resource placement, QCL assumption, scrambling ID, and new scrambling ID. The time operation setting may indicate P, SP, or AP. The frequency resource placement may be at the wideband level or at the RB level. The wideband level may be the number of PRBs and the starting PRB. The time resource placement may be at the slot level. The QCL assumption may be the associated SSB. Multiple CSI-RS resources for aggregation may have at least one different setting of time resource placement, frequency resource placement, and scrambling ID. - Option 5: Multiple CSI-RS resources for aggregation may be in M ​​or fewer consecutive slots or in consecutive / comb-shaped frequency resources. - Example: M=2 CSI-RS resources may be aggregated and associated with 64 CSI-RS ports. Each CSI-RS resource may be associated with 32 CSI-RS ports.The two CSI-RS resources are located within the same CSI-RS resource set or CSI-RS resource group, have the same frequency resource configuration, and are each located in two consecutive slots.

[0252] <<Embodiment A-3>> In aggregated CSI-RS resources having more than 32 ports, several parameters may be added or existing parameters may be rewritten. For example, these parameters may be at least one of density, new scrambling ID, number of PRBs, and start PRB. To reduce the complexity of UE measurement, a density smaller than the existing density may be set.

[0253] <Embodiment B> For FDM transmission of multiple existing port CSI-RS resources, constraints on one or more of the following options may be supported.

[0254] ◆Option 1: Multiple CSI-RS resources have the same scrambling ID. Multiple CSI-RS resources for more than 32 ports are considered a single CMR, and to simplify UE implementation, it is preferable that one scrambling ID is applied to one CMR. In this case, the UE only needs to process one scrambling ID on the same symbol.

[0255] ◆Option 2: Multiple CSI-RS resources have the same period and offset (same periodityAndOffset). It can be guaranteed that multiple CSI-RS resources are transmitted within the same slot.

[0256] ◆Option 3: Multiple CSI-RS resources have frequency resources. This option may be based on at least one of the following options 3-x. —◆Option 3-1: Multiple CSI-RS resources have the same bandwidth and within the same bandwidth, but have different frequency resources (e.g., RE / RB) within that bandwidth. Multiple CSI-RS can cover the same bandwidth (RB range). For example, multiple existing port CSI-RS resources have the same CSI frequency occupation (starting RB, number of RBs), but have different RBs (comb arrangement) by setting density = 0.5 and selecting even RBs or odd RBs. For example, multiple existing port CSI-RS resources may have the same bandwidth (number of RBs (nrofRBs)), but have different RBs depending on whether density = 0.5 is set and the starting RB is set to an even RB (evenRB) or an odd RB (oddRB). In the example in Figure 5A, two CSI-RS resources have the same bandwidth and different RB positions within the same bandwidth. In this example, the first CSI-RS resource has odd-numbered (1st, 3rd,...) RBs (even RB indices 0, 2nd,...), and the second CSI-RS resource has even-numbered (2nd, 4th,...) RBs (odd RB indices 1, 3rd,...). The two CSI-RS resources can be FDM-transmitted within the same wideband. This option allows for the implementation of only two CSI-RS resources at the same time, even if only density = 0.5 is supported, as in existing specifications. The channel characteristics measured for each resource may include broadband information. —◆Option 3-2: Multiple CSI-RS resources have the same bandwidth but are in different bandwidths. For example, this option is achieved by setting the same number of RBs but different starting RBs for multiple CSI-RS resources. This option allows for the realization of two, three, or four CSI-RS resources at the same time.The channel characteristics measured for each resource include narrowband information. In the example in Figure 5B, the three CSI-RS resources have the same bandwidth but different bandwidths (starting RB).

[0257] According to Embodiment B, the UE can appropriately configure and appropriately receive / measure multiple existing port CSI-RS resources that are FDM-decoded to support more than 32 ports.

[0258] <Embodiment C> For TDM and FDM transmission of multiple existing port CSI-RS resources, constraints on one or more of the following options may be supported. TDM and FDM transmission may be applied to the case of four existing port CSI-RS resources.

[0259] ◆Option 1: Multiple CSI-RS resources have the same scrambling ID. Multiple CSI-RS resources for more than 32 ports are considered a single CMR, and it is preferable that one scrambling ID is applied to each CMR to simplify UE implementation.

[0260] ◆Option 2: Several CSI-RS resources have the same time resource (e.g., the same slot / symbol). This option may be based on at least one of the following options 2-x: —◆Option 2-1: Each set of two of the four CSI-RS resources may be in the same slot. The four CSI-RS resources may be in two consecutive slots. For example, two sets of CSI-RS resources may have different time offsets than the other two sets of CSI-RS resources. —◆Option 2-2: All four CSI-RS resources may be in the same slot. All four CSI-RS resources may have the same period and offset (same periodityAndOffset).

[0261] ◆Option 3: Several CSI-RS resources have the same frequency resources. This option may be based on at least one of the following options 3-x. —◆Option 3-1: Of the four CSI-RS resources, each set of two CSI-RS resources on the same symbol has the same bandwidth and is within the same band, but has different frequency resources (e.g., RE / RB) within that band. In the example in Figure 6A, options 2-1 and 3-1 are applied to the four CSI-RS resources. Of the four CSI-RS resources, two CSI-RS resources and the other two CSI-RS resources are on different slots. Two CSI-RS resources on the same slot have the same bandwidth and are within the same band, but are at different frequency positions within that band. One CSI-RS resource on slot #1 and one CSI-RS resource on slot #2 have the same bandwidth, are within the same band, and are at the same frequency position within that band. In the example in Figure 6B, options 2-2 and 3-1 are applied to the four CSI-RS resources. The four CSI-RS resources are on the same slot #1. Of the four CSI-RS resources, two CSI-RS resources and the other two CSI-RS resources are on different symbols. Two CSI-RS resources on the same symbol have the same bandwidth and are within the same band, but are at different frequency positions within that band. —Option 3-2: Of the four CSI-RS resources, each set of two CSI-RS resources on the same symbol has the same bandwidth but is in a different band. In the example in Figure 7A, options 2-1 and 3-2 are applied to the four CSI-RS resources. Of the four CSI-RS resources, two CSI-RS resources and the other two CSI-RS resources are on different slots. Two CSI-RS resources on the same slot have the same bandwidth but are in different bands. One CSI-RS resource on slot #1 and one CSI-RS resource on slot #2 have the same bandwidth, are in the same band, and are at the same frequency position within that band.In the example in Figure 7B, options 2-2 and 3-2 are applied to four CSI-RS resources. The four CSI-RS resources are on the same slot #1. Of the four CSI-RS resources, two CSI-RS resources and the other two CSI-RS resources are on different symbols. Two CSI-RS resources on the same slot have the same bandwidth but are in different bands. One CSI-RS resource on slot #1 and one CSI-RS resource on slot #2 have the same bandwidth, are in the same band, and are at the same frequency position within that band. —In options 3-1 / 3-2, two CSI-RS resources on different symbols among the four CSI-RS resources may have the same bandwidth and be in the same band.

[0262] ◆Variation: Embodiment C may be applied to three CSI-RS resources. In this case, one of the four CSI-RS resources in the aforementioned examples may be omitted.

[0263] According to Embodiment C, the UE can appropriately configure and appropriately receive / measure multiple existing port CSI-RS resources that are TDM and FDM-decoded to support more than 32 ports.

[0264] <Embodiment 1> Embodiment 1 relates to the position of the CSI-RS.

[0265] A frequency density lower than 0.5 (or smaller) may be supported for the position of CSI-RS within a single slot.

[0266] In this disclosure, a frequency density lower than 0.5 may be, for example, at least one of 0.25 and 0.125, or other values ​​(for example, 0.0625).

[0267] In this disclosure, frequency [domain] density lower than 0.5, first frequency [domain] density, etc., may be interpreted as mutually interchangeable.

[0268] In this disclosure, a frequency density of 0.5 or greater may be at least one of the frequency densities supported in existing specifications (e.g., 3, 1, 0.5) and the frequency densities supported in Rel. 19 / Rel. 20 and later (e.g., 2).

[0269] In this disclosure, frequency [domain] density of 0.5 or higher, second frequency [domain] density, etc., may be interpreted interchangeably.

[0270] In this disclosure, a UE that is configured with a specific codebook type may support a first frequency density of the CSI-RS. The CSI-RS to which the first frequency density is applied may have more than 32 ports.

[0271] In this disclosure, a CSI-RS to which the first frequency density applies, a CSI-RS having more than 32 ports, a first CSI-RS, etc., may be interpreted interchangeably. In this disclosure, a CSI-RS to which the first frequency density does not apply, a CSI-RS having 32 or fewer ports, a second CSI-RS, etc., may be interpreted interchangeably.

[0272] In this disclosure, ρ may mean the frequency density applied to CSI-RS.

[0273] In this disclosure, the terms "content," "item," "value," "parameter," etc., may be interpreted as interchangeable.

[0274] In this disclosure, location, time [domain] / frequency [domain] location, resource, time / frequency resource, etc., may be interpreted interchangeably.

[0275] <<Embodiment 1.1>> In order to reduce the frequency density of the CSI-RS, a new table for identifying / determining / judging the position of the first CSI-RS / second CSI-RS may be defined by defining a first frequency density in an existing table (for example, the table shown in Figure 1).

[0276] The new table may show multiple sets / combinations / associations (hereinafter also referred to as multiple parameter sets) of multiple parameters, including frequency density (e.g., first frequency density / second frequency density). A single row in the new table may show one set / combination / association (hereinafter also referred to as one parameter set) of multiple parameters, including frequency density (e.g., first frequency density / second frequency density). The new table relating to Embodiment 1.1 may be interpreted as multiple parameter sets including first and second frequency density, multiple new parameter sets, multiple parameter sets common to first and second CSI-RS, multiple parameter sets applicable to first and second CSI-RS (both), multiple parameter sets for identifying / determining / judging the positions of first and second CSI-RS (both), multiple parameter sets relating to the positions of first and second CSI-RS (both), and so on.

[0277] The first CSI-RS / second CSI-RS may be transmitted at a time domain / frequency domain location identified / determined / judged based on a specific set of parameters corresponding to a specific row in a table (new table) common to the first CSI-RS and the second CSI-RS.

[0278] The UE may identify / determine / judge the time domain / frequency domain location of the first CSI-RS / second CSI-RS according to a specific set of parameters corresponding to a specific row in the new table. The UE may receive the first CSI-RS / second CSI-RS at the identified / determined / judged time domain / frequency domain location.

[0279] <<<Embodiment 1.1A>>> The new table may be a table to which a first frequency density has been added to all or some rows / contents (items) of the existing table. For each row to which the first frequency density has been added, items other than the frequency density (for example, number of ports, CDM type, location of component resource (k bar, l bar), CDM group index, location of each resource within the component resource ((RE, symbol), (k', l'))) may use (reuse) the contents / values ​​defined in the existing table.

[0280] Figure 8 shows an example of the position of the CSI-RS within a slot. Rows 1 through 18 of the table shown in Figure 8 are the same as the existing table. On the other hand, rows 19 through 36 of the table shown in Figure 8 are rows to which the first frequency density (0.25 and 0.125 in Figure 8) has been added compared to rows 1 through 18 of the existing table. The contents / values ​​of items other than the frequency density in rows 19 through 36 of the table shown in Figure 8 are the same as the contents / values ​​of rows 1 through 18 of the existing table. The position of the first CSI-RS may be identified / determined / judged according to one of the rows 1 through 18 of the table shown in Figure 8 (i.e., the first frequency density may not be applied to the first CSI-RS), or it may be identified / determined / judged according to one of the rows 19 through 36 of the table shown in Figure 8 (i.e., the first frequency density may be applied to the first CSI-RS). The position of the second CSI-RS may be identified / determined / judged according to one of the rows from row 1 to row 18 of the table shown in Figure 8 (i.e., the first frequency density does not have to be applied to the second CSI-RS). At least one row of the table shown in Figure 8 may be excluded / deleted.

[0281] Figure 9 shows an example of the position of the CSI-RS within a slot. Rows 1 through 16 of the table shown in Figure 9 are the same as rows 1 through 16 of the existing table. On the other hand, rows 17 and 18 of the table shown in Figure 9 are rows to which a first frequency density (0.25 and 0.125 in Figure 9) has been added compared to rows 17 and 18 of the existing table. The contents / values ​​of items other than the frequency density in rows 17 and 18 of the table shown in Figure 9 are the same as the contents / values ​​of rows 17 and 18 of the existing table. In this case, the position of the first CSI-RS may be identified / determined / judged according to one of the rows 1 through 16 of the table shown in Figure 9 (i.e., the first frequency density may not be applied to the first CSI-RS), or it may be identified / determined / judged according to one of the rows 17 and 18 of the table shown in Figure 9 (i.e., the first frequency density may be applied to the first CSI-RS). Furthermore, the position of the second CSI-RS may be specified / determined / judged according to one of the rows from row 1 to row 16 of the table shown in Figure 9 (i.e., the first frequency density does not necessarily have to be applied to the second CSI-RS). Note that the first frequency density is not limited to rows 17 and 18 of the existing table, but may be added to any row of the existing table.

[0282] The UE may receive higher-layer signaling (e.g., CSI-RS-ResourceMapping) regarding the location of the first CSI-RS / second CSI-RS. This higher-layer signaling may be information that notifies at least a portion of a specific set of parameters corresponding to a particular row in a new table. Based on this higher-layer signaling, the UE may identify / determine / determine the location of the first CSI-RS / second CSI-RS.

[0283] Upper layer signaling regarding the location of the first CSI-RS / second CSI-RS may notify the UE of at least one of the following pieces of information: ◆ Number of ports on the CSI-RS ◆ Frequency density applied to the CSI-RS (if the frequency density is less than 1, include the PRB to which the CSI-RS to which that frequency density applies is mapped)

[0284] The number of CSI-RS ports notified by upper-layer signaling regarding the location of the first CSI-RS / second CSI-RS may be 32 or less (for example, any of 1, 2, 4, 8, 12, 16, 24, or 32), or it may be more than 32 (for example, any of 48, 64, 72, 96, or 128).

[0285] The frequency density notified by upper-layer signaling regarding the location of the first CSI-RS / second CSI-RS may be a second frequency density (e.g., any of 3, 1, or 0.5) or a first frequency density (e.g., any of 0.25 or 0.125).

[0286] When a first frequency density is applied, higher-layer signaling regarding the locations of the first CSI-RS / second CSI-RS may notify the PRB to which the CSI-RS to which the first frequency density is applied is mapped. The PRB may be notified using an index of the PRB, or using a bit string indicating the location of the PRB.

[0287] <<<Embodiment 1.1B>>> A new table may be defined by adding a row in which a first frequency density is defined to an existing table. For each row in which the first frequency density is added, items other than the frequency density (for example, number of ports, density of frequency domains, CDM type, location of component resources (k-bar, l-bar), CDM group index, location of each resource within the component resource ((RE, symbol), (k', l'))) may be those defined in the existing table, or they may be those not defined in the existing table (for example, those supported in Rel. 20 and later).

[0288] Figure 10 shows an example of the position of the CSI-RS within a slot. Rows 1 through 18 of the table shown in Figure 10 are the same as the existing table. On the other hand, rows 19 and onward of the table shown in Figure 10 are new rows in which the first frequency density (0.25, 0.125 in Figure 10) is defined. The content / values ​​of items other than the frequency density in rows 19 and onward of the table shown in Figure 10 may be the same as the content / values ​​used in rows 1 through 18 of the existing table, or they may be different from the content / values ​​used in rows 1 through 18 of the existing table. The position of the first CSI-RS may be identified / determined / judged according to one of the rows 1 through 18 of the table shown in Figure 10 (i.e., the first frequency density may not be applied to the first CSI-RS), or it may be identified / determined / judged according to rows 19 and onward of the table shown in Figure 10 (i.e., the first frequency density may be applied to the first CSI-RS). The position of the second CSI-RS may be identified / determined / judged according to one of the rows from row 1 to row 18 of the table shown in Figure 10 (i.e., the first frequency density does not have to be applied to the second CSI-RS). At least one row of the table shown in Figure 10 may be excluded / deleted.

[0289] In the example shown in Figure 10, the new table may contain n rows, where n is greater than a specific number (for example, 18).

[0290] In the example shown in Figure 10, the number of ports X is defined from row 19 onwards in the new table. m (where m indicates the corresponding row, and 1 ≤ m ≤ n) may be a number of ports less than or equal to 32 (for example, any of 1, 2, 4, 8, 12, 16, 24, or 32), or a number of ports greater than 32 (for example, any of 48, 64, 72, 96, or 128).

[0291] In the example shown in Figure 10, the frequency density ρ is defined from row 19 onwards in the new table. m_0 ρ m_1... may be a second frequency density (e.g., 3, 1, 0.5) or a first frequency density (e.g., 0.25, 0.125).

[0292] In the example shown in Figure 10, the CDM type CDMTYPE is defined from row 19 onwards in the new table. m This may be an existing CDM type (for example, no CDM, FD-CDM2, CDM4, or CDM8), or it may be a CDM type newly supported in Rel. 20 or later.

[0293] In the example shown in Figure 10, the location of the component resource defined from row 19 onwards in the new table (k m_p ,l m_q ), (k m_r ,l m_s ), ... may be the location of an existing component resource, or it may be the location of a component resource newly supported in Rel. 20 or later.

[0294] In the example shown in Figure 10, the CDM group index a is defined from row 19 onwards in the new table. m_0 a m_1 ... may be existing CDM group indexes (e.g., 0, 1, ..., 15) or new CDM group indexes supported in Rel. 20 and later (e.g., 16, 17, ...).

[0295] In the example shown in Figure 10, REb in the component resource defined from row 19 onwards in the new table m_0 , b m_1 ... may be REs within existing component resources (e.g., 0, 1) or REs within component resources newly supported in Rel. 20 and later (e.g., 2, 3, ...).

[0296] In the example shown in Figure 10, the symbol c in the component resource defined from row 19 onwards in the new table m_0 , c m_1... may be symbols within existing component resources (e.g., 0, 1, 2, 3) or symbols within component resources newly supported in Rel. 20 and later (e.g., 4, 5, ...).

[0297] The UE may receive higher-layer signaling (e.g., CSI-RS-ResourceMapping) regarding the location of the first CSI-RS / second CSI-RS. This higher-layer signaling may be information that notifies at least a portion of a specific set of parameters corresponding to a particular row in a new table. Based on this higher-layer signaling, the UE may identify / determine / determine the location of the first CSI-RS / second CSI-RS.

[0298] Upper-layer signaling regarding the location of the first CSI-RS / second CSI-RS may notify the UE of at least one of the following pieces of information: ◆ Number of ports on the CSI-RS ◆ CDM type applied to the CSI-RS ◆ Frequency density applied to the CSI-RS (if the frequency density is less than 1, include the PRB to which the CSI-RS to which that frequency density applies is mapped)

[0299] The number of CSI-RS ports notified by upper-layer signaling regarding the location of the first CSI-RS / second CSI-RS may be 32 or less (for example, any of 1, 2, 4, 8, 12, 16, 24, or 32), or it may be more than 32 (for example, any of 48, 64, 72, 96, or 128).

[0300] The CDM type notified by upper-layer signaling regarding the location of the first CSI-RS / second CSI-RS may be an existing CDM type (e.g., no CDM, FD-CDM2, CDM4, or CDM8) or a CDM type newly supported in Rel. 20 or later.

[0301] The frequency density notified by upper-layer signaling regarding the location of the first CSI-RS / second CSI-RS may be a second frequency density (e.g., any of 3, 1, or 0.5) or a first frequency density (e.g., any of 0.25 or 0.125).

[0302] When a first frequency density is applied, higher-layer signaling regarding the locations of the first CSI-RS / second CSI-RS may notify the PRB to which the CSI-RS to which the first frequency density is applied is mapped. The PRB may be notified using an index of the PRB, or using a bit string indicating the location of the PRB.

[0303] <<Embodiment 1.2>> In order to reduce the frequency density of the CSI-RS, a new table may be defined, separate from the existing table (for example, the table shown in Figure 1), in which a first frequency density is defined, for identifying / determining / judging the position of the first CSI-RS.

[0304] The new table may show a first set of multiple parameter sets, including frequency density (e.g., first frequency density / second frequency density). A single row in the new table may show one of the first set of multiple parameter sets, including frequency density (e.g., first frequency density / second frequency density). The new table relating to Embodiment 1.2 may be interpreted as a set of multiple parameter sets including at least a first frequency density, a set of multiple parameter sets including a first frequency density and a second frequency density, a first set of multiple parameter sets, a new set of multiple parameter sets, a set of multiple parameter sets applied to a first CSI-RS, a set of multiple parameter sets not applied to a second CSI-RS, a set of multiple parameter sets for identifying / determining / judging the position of the first CSI-RS, a set of multiple parameter sets relating to the position of the first CSI-RS, and so on.

[0305] The existing table may show a second set of parameters including frequency density (e.g., second frequency density). A single row in the existing table may show one of the second set of parameters including frequency density. The existing table relating to Embodiment 1.2 may be interpreted as a set of parameters not including the first frequency density, a set of parameters including the second frequency density, a second set of parameters, an existing set of parameters, a set of parameters applied to the first CSI-RS / second CSI-RS, a set of parameters for identifying / determining / judging the position of the first CSI-RS / second CSI-RS, a set of parameters relating to the position of the first CSI-RS / second CSI-RS, and so on.

[0306] The first CSI-RS may be transmitted at a time domain / frequency domain location identified / determined / judged based on a specific set of parameters corresponding to a specific row in an existing / new table.

[0307] The second CSI-RS may be transmitted at a time domain / frequency domain location identified / determined / judged based on a specific set of parameters corresponding to a specific row in an existing table.

[0308] The UE may identify / determine / judge the time domain / frequency domain location of the first CSI-RS according to a specific set of parameters corresponding to a specific row in an existing table / new table. The UE may receive the first CSI-RS at the identified / determined / judged time domain / frequency domain location.

[0309] The UE may identify / determine / judge the time domain / frequency domain location of the second CSI-RS according to a specific set of parameters corresponding to a specific row in an existing table. The UE may receive the second CSI-RS at the identified / determined / judged time domain / frequency domain location.

[0310] <<<Embodiment 1.2A>>> A first frequency density may be defined for the frequency density of the new table. For items other than the frequency density of each row in the new table (for example, the number of ports, CDM type, location of the component resource (k-bar, l-bar), CDM group index, and location of each resource within the component resource ((RE, symbol), (k', l'))), the contents / values ​​defined in the existing table may be used (reused).

[0311] Figures 11A and 11B show an example of the position of the CSI-RS within a slot. The table shown in Figure 11A is the same as the existing table. On the other hand, the table shown in Figure 11B is a new table to which a first frequency density (0.25 and 0.125 in Figure 11B) has been added to the existing table. The contents / values ​​of the items other than the frequency density in the table shown in Figure 11B are the same as the contents / values ​​in the existing table. The position of the first CSI-RS may be identified / determined / judged according to one of the rows from row 1 to row 18 of the table shown in Figure 11A (i.e., the first frequency density may not be applied to the first CSI-RS), or it may be identified / determined / judged according to one of the rows from row 1 to row 18 of the table shown in Figure 11B (i.e., the first frequency density may be applied to the first CSI-RS). The position of the second CSI-RS may be identified / determined / judged according to one of the rows from row 1 to row 18 of the table shown in Figure 11A (i.e., the first frequency density may not be applied to the second CSI-RS).

[0312] The UE may receive a first upper layer signaling (e.g., CSI-RS-ResourceMapping-LessDensity) regarding the location of the first CSI-RS. The first upper layer signaling may be information indicating at least a portion of a specific set of parameters corresponding to a particular row in a new table. Based on the first upper layer signaling, the UE may identify / determine / determine the location of the first CSI-RS.

[0313] The UE may receive second-level upper-layer signaling (e.g., CSI-RS-ResourceMapping) regarding the location of the first CSI-RS / second CSI-RS. The second-level upper-layer signaling may be information that notifies at least a portion of a specific set of parameters corresponding to a particular row in an existing table. Based on the second-level upper-layer signaling, the UE may identify / determine / judge the location of the first CSI-RS / second CSI-RS.

[0314] The UE may switch the tables it references based on whether the first upper layer signaling is configured / notified (i.e., whether the first upper layer signaling or the second upper layer signaling is configured / notified).

[0315] For example, in Figure 11A / Figure 11B, if the first upper layer signaling is not set (if the second upper layer signaling is set), the UE may identify / determine / determine the location of the time domain / frequency domain of the first CSI-RS / second CSI-RS according to a specific set of parameters corresponding to a specific row in the table shown in Figure 11A (existing table). If the first upper layer signaling is set (if the second upper layer signaling is not set), the UE may identify / determine / determine the location of the time domain / frequency domain of the first CSI-RS according to a specific set of parameters corresponding to a specific row in the table shown in Figure 11B (new table).

[0316] First-layer signaling / second-layer signaling may notify the UE of at least one of the following pieces of information: ◆ Number of ports on the CSI-RS ◆ Frequency density applied to the CSI-RS (if the frequency density is less than 1, include the PRB to which the CSI-RS to which that frequency density applies is mapped)

[0317] The number of CSI-RS ports notified by the first upper layer signaling may be 32 or less (for example, 1, 2, 4, 8, 12, 16, 24, or 32), or it may be more than 32 (for example, 48, 64, 72, 96, or 128).

[0318] The frequency density notified by the first upper layer signaling may be a second frequency density (e.g., any of 3, 1, or 0.5) or a first frequency density (e.g., any of 0.25 or 0.125).

[0319] When a first frequency density is applied, the first upper-layer signaling may notify the PRB to which the CSI-RS to which the first frequency density is applied is mapped. The PRB may be notified using its index, or using a bit string indicating the location of the PRB.

[0320] The number of CSI-RS ports notified by the second upper layer signaling may be 32 or less (for example, any of 1, 2, 4, 8, 12, 16, 24, or 32 ports).

[0321] The frequency density notified by the second upper layer signaling may be the second frequency density (for example, 3, 1, or 0.5).

[0322] <<<Embodiment 1.2B>>> A first frequency density may be defined for the frequency density of the new table. For items other than the frequency density of each row in the new table (for example, the number of ports, the density of the frequency domain, the CDM type, the location of the component resource (k-bar, l-bar), the CDM group index, and the location of each resource within the component resource ((RE, symbol), (k', l'))), the contents / values ​​defined in the existing table may be used, or contents / values ​​not defined in the existing table (for example, contents / values ​​supported in Rel. 20 and later) may be used.

[0323] Figures 12A and 12B show an example of the position of the CSI-RS within a slot. The table shown in Figure 12A is the same as the existing table. On the other hand, the table shown in Figure 12B is a new table in which a first frequency density (0.25 and 0.125 in Figure 12B) is defined. The contents / values ​​of items other than the frequency density in the table shown in Figure 12B may be the same as the contents / values ​​used in the existing table, or they may be different from the contents / values ​​used in the existing table. The position of the first CSI-RS may be identified / determined / judged according to one row of the table shown in Figure 12A (i.e., the first frequency density may not be applied to the first CSI-RS), or it may be identified / determined / judged according to one row of the table shown in Figure 12B (i.e., the first frequency density may be applied to the first CSI-RS). The position of the second CSI-RS may be identified / determined / determined according to one row of the table shown in Figure 12A (i.e., the first frequency density may not be applied to the second CSI-RS).

[0324] In the example shown in Figure 12B, the new table may contain n rows.

[0325] In the example shown in Figure 12B, the number of ports X is defined in the new table. m (where m indicates the corresponding row, and 1 ≤ m ≤ n) may be a number of ports less than or equal to 32 (for example, any of 1, 2, 4, 8, 12, 16, 24, or 32), or a number of ports greater than 32 (for example, any of 48, 64, 72, 96, or 128).

[0326] In the example shown in Figure 12B, the frequency density ρ defined in the new table m_0 ρ m_1 ... may be a second frequency density (e.g., 3, 1, 0.5) or a first frequency density (e.g., 0.25, 0.125).

[0327] In the example shown in Figure 12B, the CDM type CDMTYPE is defined in the new table. mThis may be an existing CDM type (for example, no CDM, FD-CDM2, CDM4, or CDM8), or it may be a CDM type newly supported in Rel. 20 or later.

[0328] In the example shown in Figure 12B, the location of the component resource defined in the new table (k m_p ,l m_q ), (k m_r ,l m_s ), ... may be the location of an existing component resource, or it may be the location of a component resource newly supported in Rel. 20 or later.

[0329] In the example shown in Figure 12B, the CDM group index a defined in the new table m_0 a m_1 ... may be existing CDM group indexes (e.g., 0, 1, ..., 15) or new CDM group indexes supported in Rel. 20 and later (e.g., 16, 17, ...).

[0330] In the example shown in Figure 12B, REb in the component resource defined in the new table m_0 , b m_1 ... may be REs within existing component resources (e.g., 0, 1) or REs within component resources newly supported in Rel. 20 and later (e.g., 2, 3, ...).

[0331] In the example shown in Figure 12B, symbol c in the component resource defined in the new table m_0 , c m_1 ... may be symbols within existing component resources (e.g., 0, 1, 2, 3) or symbols within component resources newly supported in Rel. 20 and later (e.g., 4, 5, ...).

[0332] The UE may receive a first upper layer signaling (e.g., CSI-RS-ResourceMapping-LessDensity) regarding the location of the first CSI-RS. The first upper layer signaling may be information indicating at least a portion of a specific set of parameters corresponding to a particular row in a new table. Based on the first upper layer signaling, the UE may identify / determine / determine the location of the first CSI-RS.

[0333] The UE may receive second-level upper-layer signaling (e.g., CSI-RS-ResourceMapping) regarding the location of the first CSI-RS / second CSI-RS. The second-level upper-layer signaling may be information that notifies at least a portion of a specific set of parameters corresponding to a particular row in an existing table. Based on the second-level upper-layer signaling, the UE may identify / determine / judge the location of the first CSI-RS / second CSI-RS.

[0334] The UE may switch the tables it references based on whether the first upper layer signaling is configured / notified (i.e., whether the first upper layer signaling or the second upper layer signaling is configured / notified).

[0335] For example, in Figure 12A / Figure 12B, if the first upper layer signaling is not set (if the second upper layer signaling is set), the UE may identify / determine / determine the location of the time domain / frequency domain of the first CSI-RS / second CSI-RS according to a specific set of parameters corresponding to a specific row in the table shown in Figure 12A (existing table). If the first upper layer signaling is set (if the second upper layer signaling is not set), the UE may identify / determine / determine the location of the time domain / frequency domain of the first CSI-RS according to a specific set of parameters corresponding to a specific row in the table shown in Figure 12B (new table).

[0336] First-layer signaling / second-layer signaling may notify the UE of at least one of the following pieces of information: ◆ Number of ports on the CSI-RS ◆ CDM type applied to the CSI-RS ◆ Frequency density applied to the CSI-RS (if the frequency density is less than 1, include the PRB to which the CSI-RS to which that frequency density applies is mapped)

[0337] The number of CSI-RS ports notified by the first upper layer signaling may be 32 or less (for example, 1, 2, 4, 8, 12, 16, 24, or 32), or it may be more than 32 (for example, 48, 64, 72, 96, or 128).

[0338] The CDM type notified by the first upper layer signaling may be an existing CDM type (e.g., no CDM, FD-CDM2, CDM4, or CDM8) or a CDM type newly supported in Rel. 20 or later.

[0339] The frequency density notified by the first upper layer signaling may be a second frequency density (e.g., any of 3, 1, or 0.5) or a first frequency density (e.g., any of 0.25 or 0.125).

[0340] When a first frequency density is applied, the first upper-layer signaling may notify the PRB to which the CSI-RS to which the first frequency density is applied is mapped. The PRB may be notified using its index, or using a bit string indicating the location of the PRB.

[0341] The number of CSI-RS ports notified by the second upper layer signaling may be 32 or less (for example, any of 1, 2, 4, 8, 12, 16, 24, or 32 ports).

[0342] The CDM type notified by the second upper layer signaling may be an existing CDM type (for example, no CDM, FD-CDM2, CDM4, or CDM8).

[0343] The frequency density notified by the second upper layer signaling may be the second frequency density (for example, 3, 1, or 0.5).

[0344] <<Embodiment 1.3>> The UE does not have to assume that a CSI-RS with the first frequency density applied is set if certain conditions are not met (it may assume that a CSI-RS with the first frequency density applied is set if certain conditions are met).

[0345] The specific conditions may be at least one of the following: ◆ A specific codebook type is set. ◆ The number of CSI-RS ports is greater than a specific number (e.g., 32, 64).

[0346] A specific codebook type may be at least one of the aforementioned codebooks (e.g., Type 1 single-panel codebook, Type 1 multi-panel codebook, Type 2 codebook, extended Type 2 codebook, Type 2 port selection codebook, additional extended Type 2 port selection codebook, Type 2 codebook for CJT, additional extended Type 2 codebook for CJT, extended Type 2 codebook for predictive PMI, additional extended Type 2 codebook for predictive PMI) and codebooks newly supported in Rel. 20 and later.

[0347] <<Embodiment 1.4>> Specific parameters for indicating the frequency density may be defined.

[0348] <<<Embodiment 1.4A>>> The UE may identify / determine / determine / calculate the frequency density (e.g., first frequency density / second frequency density) to be applied to the CSI-RS (e.g., first CSI-RS) based on an existing table [a specific set of parameters corresponding to a specific row in the existing table] (or the frequency density (e.g., second frequency density) corresponding to a specific row in the existing table) and specific parameters. The UE may identify / determine / determine the location of the CSI-RS based on the identified / determined / determined / calculated frequency density.

[0349] The UE may specify / determine / determine the frequency density to be applied to the CSI-RS by dividing the frequency density specified in an existing table (e.g., 3, 1, 0.5) by a specific parameter.

[0350] The specific parameter may be a specific integer value (e.g., 1, 2, or 4) such that the frequency density applied to CSI-RS is a specific value (e.g., 1, 0.5, 0.25, or 0.125).

[0351] For example, if a frequency density of 1 is set / notified and a specific parameter of 4 is set / notified, the UE may identify / determine / determine that the frequency density applied to CSI-RS is 0.25.

[0352] For example, if a frequency density of 0.5 is set / notified and a specific parameter of 2 is set / notified, the UE may identify / determine / determine that the frequency density applied to CSI-RS is 0.25.

[0353] For example, if a frequency density of 0.5 is set / notified and a specific parameter of 4 is set / notified, the UE may identify / determine / determine that the frequency density applied to CSI-RS is 0.125.

[0354] <<<Embodiment 1.4B>>> The UE may identify / determine / determine / calculate a frequency density (e.g., first frequency density / second frequency density) to be applied to the CSI-RS (e.g., first CSI-RS) based on a new table (e.g., a new table in Embodiments 1.1 / 1.2) [a specific set of parameters corresponding to a specific row in the new table] (or a frequency density (e.g., second frequency density) corresponding to a specific row in the new table) and specific parameters. The UE may identify / determine / determine the location of the CSI-RS based on the identified / determined / determined / calculated frequency density.

[0355] The UE may identify / determine / determine the frequency density to be applied to the CSI-RS by dividing the frequency density defined in the new table by a specific parameter.

[0356] The frequency densities defined in the new table (used for identifying / determining / judging / calculating the frequency density applicable to CSI-RS) may include at least one of the frequency densities defined in the existing table and frequency densities other than those defined in the existing table.

[0357] For example, the frequency densities specified in the new table may include at least one of 3, 2, 1, 0.5, 0.25, and 0.125. In this case, 3, 1, and 0.5 are frequency densities specified in the existing table, while 2, 0.25, and 0.125 are frequency densities not specified in the existing table (frequency densities newly supported in the new table).

[0358] The specific parameter may be a specific integer value (e.g., 1, 2, 4, 8, 16) such that the frequency density applied to CSI-RS is a specific value (e.g., one of 1, 0.5, 0.25, or 0.125).

[0359] For example, if a frequency density of 2 is set / notified and a specific parameter of 8 is set / notified, the UE may identify / determine / determine that the frequency density of CSI-RS is 0.25.

[0360] For example, if a frequency density of 2 is set / notified and a specific parameter of 16 is set / notified, the UE may identify / determine / determine that the frequency density of CSI-RS is 0.125.

[0361] <<<Embodiment 1.4C>>> The values ​​of specific parameters may be set / notified by the NW using upper-layer signaling, or they may be based on UE capabilities.

[0362] If the specific parameter is not set / notified by the network, the user audience (UE) may assume / determine / determine that the specific parameter is 1 (i.e., the second frequency density is applied to CSI-RS).

[0363] If no CSI-RS with more than 32 ports (first CSI-RS) is configured (and a CSI-RS with 32 or fewer ports (second CSI-RS) is configured), the UE does not need to assume that the specific parameter is a value other than 1 (it may assume that the specific parameter is 1 (i.e., the second frequency density is applied to the CSI-RS)).

[0364] UE does not have to assume that the frequency density identified / determined / judged / calculated based on the existing table (or the second frequency density defined in the existing table) and specific parameters is a value other than a specific value (e.g., 1, 0.5, 0.25, 0.125) (it may assume that the frequency density identified / determined / judged / calculated based on the existing table (or the second frequency density defined in the existing table) and specific parameters is a specific value (e.g., 1, 0.5, 0.25, 0.125)).

[0365] According to Embodiment 1 described above, the UE can appropriately identify, determine, and judge the location of CSI-RS with a frequency density of less than 0.5.

[0366] <Embodiment 2> The second embodiment relates to constraints / conditions on the position of the CSI-RS.

[0367] <<Analysis>> In the existing specifications, the number of PRBs for a CSI-RS resource is set by upper-layer signaling (nrofRBs in CSI-FrequencyOccupation). The number of PRBs for a CSI-RS resource is only allowed to be a multiple of 4. The minimum number of configurable PRBs is 24. If the number of configured PRBs is greater than the width (size) of the corresponding bandwidth portion (BWP), the UE assumes that the CSI-RS bandwidth is the same as the width of that BWP.

[0368] In the existing specification, the PRB (index) from which a CSI-RS resource is started is set by upper-layer signaling (startingRB in CSI-FrequencyOccupation). The PRB (index) from which a CSI-RS resource is started is set in relation to Common Resource Block (CRB) #0 in the Common Resource Block Grid. The PRB (index) from which a CSI-RS resource is started is only allowed to be a multiple of 4, including 0.

[0369] Based on these provisions in the existing specifications, it is assumed that the total number of PRBs in CSI-RS will be only multiples of 4.

[0370] If the frequency density applied to CSI-RS is a specific value (e.g., 0.125), then in some combinations of these higher-layer signalings, CSI-RS may not be present (in the configured PRB).

[0371] <<Constraints / Conditions>> For CSI-RS mappings to which a frequency density lower than 0.5 is applied, at least one of the following constraints / conditions may be specified.

[0372] <<<Constraint / Condition 1>>> Constraints / conditions may be specified between the number of PRBs and the frequency density.

[0373] If at least one of the number of PRBs indicated / configured by upper-layer signaling (e.g., nrofRBs) and the PRB (index) to which a CSI-RS resource is initiated, indicated / configured by upper-layer signaling (e.g., startingRB), is not a multiple of a specific number (e.g., 8), then the UE does not need to assume that a frequency density of a specific value less than 0.5 (e.g., 0.125) is set / applied. In other words, if both the number of PRBs indicated / configured by upper-layer signaling and the PRB (index) to which a CSI-RS resource is initiated, indicated / configured by upper-layer signaling, is a multiple of a specific number, then the UE may assume that a frequency density of a specific value less than 0.5 (e.g., 0.125) is set / applied.

[0374] <<<Constraint / Condition 2>>> Constraints / conditions regarding TDM / FDM may be specified.

[0375] If a CSI-RS to which a frequency density lower than 0.5 is applied is TDM / FDM to multiple CSI-RS resources, resulting in a number of ports greater than 32, the same constraints / conditions as in Embodiments A / B / C may apply.

[0376] <<<Constraint / Condition 3>>> A UE with a frequency density ρ lower than 0.5 does not need to be expected to have a precoder granularity (e.g., precoderGranularity) smaller than 1 / ρ (or less than or equal to 1 / ρ) and a subband size (e.g., subbandSize) smaller than 1 / ρ (or less than or equal to 1 / ρ).

[0377] For example, if ρ = 0.25 is set, at least one of the precoder granularity and subband size does not necessarily have to be assumed to be less than 4.

[0378] To support a specific frequency density (e.g., ρ = 0.125), a specific value (e.g., 8) may be added to the candidate precoder granularity.

[0379] UE is a precoder granularity in the frequency direction P' BWP,i It can be assumed that these are consecutive resource blocks. P' BWP,i It may be equal to one of the values ​​{2, 4, 8, 12, ..., 32, wideband}.

[0380] <<<Constraint / Condition 4>>> Constraints / Conditions 1 to 3 may apply if the number of CSI-RS ports is greater than a certain number. The certain number may be 32, 64, 128, or any other value (e.g., 48, 64, 72, 96).

[0381] According to Embodiment 2 described above, even when the frequency density applied to the CSI-RS is a specific value (for example, 0.125), the CSI-RS can be appropriately positioned (in the configured PRB).

[0382] <Other> The UE may obtain the CSI by measuring the CSI-RS (resource) using a port to which at least one of the above embodiments is applied.

[0383] <Supplement> <<Notification of Information to UE>> In the embodiments described above, notification of any information from the Network (NW) (e.g., Base Station (BS)) to the UE (in other words, reception of any information from the BS at the UE) may be performed using physical layer signaling (e.g., DCI), higher layer signaling (e.g., RRC signaling, MAC CE), specific signals / channels (e.g., PDCCH, PDSCH, reference signal), or a combination thereof.

[0384] If the above notification is made by a MAC CE, the MAC CE may be identified by the inclusion of a new Logical Channel ID (LCID) not defined in existing standards in the MAC subheader.

[0385] If the above notification is made by DCI, the notification may be made by a specific field of the DCI, a Radio Network Temporary Identifier (RNTI) used to scramble the Cyclic Redundancy Check (CRC) bits assigned to the DCI, or the format of the DCI.

[0386] Furthermore, the notification of arbitrary information to the UE in the above-described embodiment may be periodic, semi-persistent, or aperiodic.

[0387] <<Notification of Information from UE>> Notification of any information from the UE to the NW in the embodiments described above (in other words, transmission / reporting of any information from the UE to the BS) may be performed using physical layer signaling (e.g., UCI), higher layer signaling (e.g., RRC signaling, MAC CE), specific signals / channels (e.g., PUCCH, PUSCH, PRACH, reference signals), or a combination thereof.

[0388] If the above notification is made by a MAC CE, the MAC CE may be identified by the inclusion of a new LCID not specified in existing standards in the MAC subheader.

[0389] If the above notice is made by the UCI, the notice may be transmitted using PUCCH or PUSCH.

[0390] Furthermore, the notification of any information from the UE in the above-described embodiment may be periodic, semi-persistent, or aperiodic.

[0391] <<Regarding the application of each embodiment>> In UE / BS, specific (one or more) processes / operations / controls / assumptions / information for at least one of the embodiments described above may be applied (or used) if any or more of the following conditions are met: - A higher-layer parameter indicating the specific process / operation / control / assumption / information is set; - The specific process / operation / control / assumption / information is determined based on the relevant higher-layer parameter; - The specific process / operation / control / assumption / information is designated / activated / triggered by MAC CE / DCI / UCI / Resource / Channel / RS; - A specific UE capability indicating (or related to) the specific process / operation / control / assumption / information is reported or supported; - The application of the specific process / operation / control / assumption / information is determined based on specific conditions.

[0392] The above-mentioned specific UE capabilities may represent at least one of the following: - Supporting the above-mentioned specific processing / operation / control / assumment / information; - Supporting a specific value of frequency density (e.g., ρ=0.25, ρ=0.125); - Supporting a specific table relating to the CSI-RS location (e.g., the novel table of Embodiment 1); - Supporting a specific codebook scheme / codebook type (e.g., the codebook scheme / codebook type supported in Rel. 20 and later).

[0393] Furthermore, the above-mentioned specific UE capability may be a capability that applies across all frequencies (commonly regardless of frequency), a capability per frequency (e.g., one or a combination thereof, such as cell, band, band combination, BWP, component carrier, etc.), a capability per frequency range (e.g., Frequency Range 1 (FR1), FR2, FR3, FR4, FR5, FR2-1, FR2-2), a capability per subcarrier spacing (SCS), or a capability per feature set (FS) or feature set per component-carrier (FSPC).

[0394] Furthermore, the specific UE capabilities described above may be capabilities that apply across all duplexing schemes (common to all duplexing schemes regardless of the duplexing scheme), or they may be capabilities specific to each duplexing scheme (e.g., Time Division Duplex (TDD), Frequency Division Duplex (FDD)).

[0395] If the above conditions are not met, UE / BS may follow the behavior specified in existing 3GPP releases.

[0396] (Note) The following inventions are added with respect to one embodiment of the present disclosure. [Note 1] A terminal having: a control unit that determines the positions of a first time domain and a frequency domain of a first channel state information reference signal (CSI-RS) to which a frequency density of less than 0.5 is applied, and the positions of a second time domain and a frequency domain of a second CSI-RS to which a frequency density of 0.5 or more is applied; and a receiving unit that receives at least one of the first CSI-RS transmitted at the positions of the first time domain and the frequency domain, and the second CSI-RS transmitted at the positions of the second time domain and the frequency domain. [Note 2] The terminal according to Note 1, wherein the control unit determines the positions of the first time domain and the frequency domain and the positions of the second time domain and the frequency domain using a plurality of parameter sets common to the first CSI-RS and the second CSI-RS. [Note 3] The terminal according to Note 1 or Note 2, wherein the control unit determines the position of the first time domain and frequency domain using a first set of parameters, and determines the position of the second time domain and frequency domain using a second set of parameters different from the first set of parameters. [Note 4] The terminal according to any one of Notes 1 to 3, wherein the control unit determines the frequency density applied to the first CSI-RS based on a set of parameters for determining the position of the second time domain and frequency domain, and a specific parameter.

[0397] (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 of the wireless communication methods according to the above embodiments of this disclosure, or a combination thereof.

[0398] Figure 13 shows an example of a schematic configuration of a wireless communication system according to one embodiment. The wireless communication system 1 (which may also be simply called 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).

[0399] 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 the like.

[0400] 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.

[0401] 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))).

[0402] 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, number, shape, size, etc., 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.

[0403] The wireless communication system 1 may utilize Multi Input Multi Output (MIMO). For example, one cell may be formed by one antenna / base station 10, or by multiple antennas / base stations 10. One [virtual] cell (which may be called a supercell, for example) may be composed of multiple [virtual] cells (which may be called subcells, for example). A supercell may correspond to a cell with a fixed physical range, and a subcell may correspond to a cell whose physical range fluctuates quasi-statically / dynamically. In this case, the wireless communication system 1 may be called a cell-free system.

[0404] 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).

[0405] 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. Note that the frequency bands and definitions of FR1 and FR2 are not limited to these, and for example, FR1 may be in a frequency band higher than FR2.

[0406] Furthermore, the user terminal 20 may communicate in each CC using at least one of Time Division Duplex (TDD) and Frequency Division Duplex (FDD).

[0407] Multiple base stations 10 may be connected by wire (e.g., optical fiber compliant with Common Public Radio Interface (CPRI), X2 / Xn interface, etc.) or wireless (e.g., NR communication). For example, when 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.

[0408] 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.

[0409] The core network 30 may include network functions (NF) such as User Plane Function (UPF), Access and Mobility Management Function (AMF), Session Management Function (SMF), Unified Data Management (UDM), Application Function (AF), Data Network (DN), Location Management Function (LMF), and Operation, Administration and Maintenance (Management) (OAM). Multiple functions may be provided by a single network node. Furthermore, communication with an external network (e.g., the Internet) may occur via the DN.

[0410] The user terminal 20 may be a terminal that supports at least one of the following communication methods: LTE, LTE-A, 5G, etc.

[0411] 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-OFDM), etc., may be used in at least one of the downlink (DL) and uplink (UL).

[0412] 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.

[0413] 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, which is shared by each user terminal 20.

[0414] 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.

[0415] 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.

[0416] 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.

[0417] Furthermore, the DCI that schedules PDSCH may be called DL assignment, DL DCI, etc., and the DCI that schedules PUSCH may be called UL grant, UL DCI, etc. Furthermore, PDSCH may be read as DL data, and PUSCH may be read as UL data.

[0418] 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. A UE may monitor CORESETs associated with a given search space based on the search space configuration.

[0419] 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.

[0420] PUCCH may transmit uplink control information (UCI) including at least one of channel state information (CSI), delivery acknowledgment information (for example, 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.

[0421] 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.

[0422] 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, the DL-RS may include 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.

[0423] 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. Note that SS, SSB, etc. may also be called reference signals.

[0424] Furthermore, in the wireless communication system 1, the uplink reference signal (UL-RS) may include a sounding reference signal (SRS), a demodulation reference signal (DMRS), etc. The DMRS may also be called a user-specific reference signal (UE-specific Reference Signal).

[0425] (Base Station) Figure 14 shows an example of the configuration of a base station according to one embodiment. The base station 10 includes a control unit 110, a transmitting / receiving unit 120, a transmitting / receiving antenna 130, and a transmission line interface 140. Note that one or more of the control unit 110, the transmitting / receiving unit 120, the transmitting / receiving antenna 130, and the transmission line interface 140 may be provided.

[0426] 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.

[0427] The control unit 110 controls the entire base station 10. The control unit 110 can be composed of a controller, control circuit, etc., as described based on common understanding in the technical field related to this disclosure.

[0428] 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 transmitting / receiving unit 120, transmitting / receiving antenna 130, and 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 transmitting / receiving 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 wireless resources, etc.

[0429] 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.

[0430] 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.

[0431] 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.

[0432] 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.

[0433] The transmitting / receiving unit 120 may use digital beamforming (e.g., precoding), analog beamforming (e.g., phase rotation), or the like to form at least one of the transmitting beam and the receiving beam.

[0434] 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), and the Medium Access Control (MAC) layer (e.g., HARQ retransmission control), to generate a bit sequence to be transmitted.

[0435] 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.

[0436] 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.

[0437] 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.

[0438] The transmitting / receiving unit 120 (receiving processing unit 1212) may apply reception processing such as analog-to-digital conversion, Fast Fourier Transform (FFT) processing, Inverse Discrete Fourier Transform (IDFT) processing (if necessary), filtering, demapping, demodulation, decoding (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.

[0439] 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.

[0440] The transmission path interface 140 may send and receive signals (backhaul signaling) with devices included in the core network 30 (e.g., network nodes that provide NF), other base stations 10, etc., and may acquire and transmit user data (user plane data), control plane data, etc. for the user terminal 20.

[0441] 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.

[0442] The base station 10 may be separated into three elements: a Radio Unit (RU), a Distributed Unit (DU), and a Central Unit (CU). For example, the RU may implement RF processing (digital beamforming, digital-to-analog conversion, analog beamforming, etc.) and lower-level physical layer functions (precoding, IFFT, FFT, etc.). The DU may implement higher-level physical layer functions (coding to resource element mapping, etc.), MAC layer functions, and RLC layer functions. The CU may implement PDCP layer, Service Data Adaptation Protocol (SDAP) layer, and RRC layer functions.

[0443] In this disclosure, base station 10 may include a single device that implements all the functions of RU, DU, and CU, or it may include multiple devices that each implement some of the functions of RU, DU, and CU and are connected to each other. In this disclosure, base station 10 may be interpreted as RU / DU / CU.

[0444] The control unit 110 may determine the positions of the first time domain and frequency domain of the first channel state information reference signal (CSI-RS) to which a frequency density of less than 0.5 is applied, and the positions of the second time domain and frequency domain of the second CSI-RS to which a frequency density of 0.5 or more is applied.

[0445] The transmitting / receiving unit 120 may transmit at least one of the first CSI-RS at the location in the first time domain and frequency domain, and the second CSI-RS at the location in the second time domain and frequency domain.

[0446] (User Terminal) Figure 15 shows an example of the configuration of a user terminal according to one embodiment. The user terminal 20 includes a control unit 210, a transmitting / receiving unit 220, and a transmitting / receiving antenna 230. Note that one or more of the control unit 210, the transmitting / receiving unit 220, and the transmitting / receiving antenna 230 may be provided.

[0447] In this example, the functional blocks of the characteristic parts of this embodiment are mainly shown, and it may be assumed that the user terminal 20 also has other functional blocks necessary for wireless communication. Some of the processing of each part described below may be omitted.

[0448] The control unit 210 controls the entire user terminal 20. The control unit 210 can be composed of a controller, control circuit, etc., as described based on common understanding in the technical field related to this disclosure.

[0449] The control unit 210 may control signal generation, mapping, etc. The control unit 210 may also control transmission and reception, measurement, etc., using the transmitting / receiving unit 220 and the transmitting / receiving antenna 230. The control unit 210 may generate data to be transmitted as signals, control information, sequences, etc., and transfer them to the transmitting / receiving unit 220.

[0450] The transmitting / receiving 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 transmitting / receiving unit 220 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.

[0451] The transmitting / receiving unit 220 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 2211 and an RF unit 222. The receiving unit may consist of a receiving processing unit 2212, an RF unit 222 and a measuring unit 223.

[0452] The transmitting and receiving antenna 230 can be composed of an antenna described based on common understanding in the art relating to this disclosure, such as an array antenna.

[0453] The transmitting / receiving unit 220 may receive the downlink channel, synchronization signal, downlink reference signal, etc. The transmitting / receiving unit 220 may also transmit the uplink channel, uplink reference signal, etc.

[0454] The transmitting / receiving unit 220 may use digital beamforming (e.g., precoding), analog beamforming (e.g., phase rotation), or the like to form at least one of the transmitting beam and the receiving beam.

[0455] The transmitting / receiving unit 220 (transmission processing unit 2211) may perform PDCP layer processing, RLC layer processing (e.g., RLC retransmission control), MAC layer processing (e.g., HARQ retransmission control), etc., on data and control information acquired from the control unit 210 to generate a bit sequence to be transmitted.

[0456] 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.

[0457] 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.

[0458] 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.

[0459] 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.

[0460] 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.

[0461] 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.

[0462] The measurement unit 223 may derive channel measurements for CSI calculation based on channel measurement resources. Channel measurement resources may be, for example, Non Zero Power (NZP) CSI-RS resources. The measurement unit 223 may also derive interference measurements for CSI calculation based on interference measurement resources. Interference measurement resources may be at least one of the following: NZP CSI-RS resources for interference measurement, CSI-Interference Measurement (IM) resources, etc. CSI-IM may also be called CSI-Interference Management (IM), and may be interpreted interchangeably with Zero Power (ZP) CSI-RS. In this disclosure, CSI-RS, NZP CSI-RS, ZP CSI-RS, CSI-IM, CSI-SSB, etc., may be interpreted interchangeably.

[0463] In this disclosure, the transmitting unit and receiving unit of the user terminal 20 may be composed of at least one of a transmitting / receiving unit 220 and a transmitting / receiving antenna 230.

[0464] The control unit 210 may determine the positions of the first time domain and frequency domain of the first channel state information reference signal (CSI-RS) to which a frequency density of less than 0.5 is applied, and the positions of the second time domain and frequency domain of the second CSI-RS to which a frequency density of 0.5 or more is applied.

[0465] The transmitting / receiving unit 220 may receive at least one of the first CSI-RS transmitted at the location in the first time domain and frequency domain, and the second CSI-RS transmitted at the location in the second time domain and frequency domain.

[0466] The control unit 210 may determine the positions of the first time domain and frequency domain and the positions of the second time domain and frequency domain using a set of parameters common to the first CSI-RS and the second CSI-RS.

[0467] The control unit 210 may determine the positions of the first time domain and frequency domain using a first set of parameters, and may determine the positions of the second time domain and frequency domain using a second set of parameters different from the first set of parameters.

[0468] The control unit 210 may determine the frequency density applied to the first CSI-RS based on a set of parameters for determining the position of the second time domain and frequency domain, and a specific parameter.

[0469] (Hardware Configuration) The block diagram used in the description of the above embodiment shows functional units. These functional blocks (components) are realized by any combination of at least one of hardware and software. Furthermore, the method of realizing each functional block is not particularly limited. That is, each functional block may be realized using one device that is physically or logically coupled, or it may be realized using two or more physically or logically separated devices that are directly or indirectly connected (for example, using wired or wireless connections). A functional block may also be realized by combining the above one device or the above multiple devices with software.

[0470] Here, functions include, but are not limited to, judgment, decision, determination, calculation, calculation, processing, derivation, investigation, exploration, confirmation, reception, transmission, output, access, resolution, selection, selection, establishment, comparison, assumption, expectation, consideration, broadcasting, notifying, communicating, forwarding, configuring, reconfiguring, allocating (mapping), and assigning. For example, a functional block (configuration part) that enables transmission may be called a transmitting unit or transmitter. In all cases, as mentioned above, the method of implementation is not particularly limited.

[0471] For example, a base station, user terminal, etc. in one embodiment of the present disclosure may function as a computer that processes the wireless communication method of the present disclosure. Figure 16 is a diagram showing an example of the hardware configuration of a base station and user terminal according to one embodiment. The base station 10 and user terminal 20 described above may be physically configured as a computer device including a processor 1001, memory 1002, storage 1003, communication device 1004, input device 1005, output device 1006, bus 1007, etc.

[0472] 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 without some of the devices.

[0473] For example, although only one processor 1001 is shown in the diagram, there may be multiple processors. Furthermore, the processing may be performed by one processor, or it may be performed by two or more processors simultaneously, sequentially, or by other means. Note that the processor 1001 may be implemented using one or more chips.

[0474] 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 control at least one of reading and writing data in the memory 1002 and storage 1003.

[0475] 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 devices, 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.

[0476] 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.

[0477] The 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. The memory 1002 may also be called a register, cache, or main memory. The memory 1002 can store executable programs (program code), software modules, etc., for carrying out a wireless communication method according to one embodiment of the present disclosure.

[0478] The 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 Use Disk, a Blu-ray (registered trademark) 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. The storage 1003 may also be called an auxiliary storage device.

[0479] 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 transmitting unit 120a (220a) and receiving unit 120b (220b).

[0480] 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).

[0481] 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.

[0482] 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.

[0483] Furthermore, devices included in the core network 30 (for example, network nodes that provide NF) may also be implemented using the functional block / hardware configuration described above.

[0484] (Variations) 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.

[0485] 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.

[0486] Here, the neurology may be communication parameters applied to at least one of the transmission and reception of a signal or channel. The neurology 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, and specific windowing processes performed by the transceiver in the time domain.

[0487] 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.

[0488] A slot may include multiple minislots. Each minislot may consist of one or more symbols in the time domain. Minislots may also be called subslots. Minislots may consist of fewer symbols than a slot. A PDSCH (or PUSCH) transmitted in a time unit larger than a minislot may be called a PDSCH (PUSCH) mapping type A. A PDSCH (or PUSCH) transmitted using minislots may be called a PDSCH (PUSCH) mapping type B.

[0489] 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.

[0490] For example, one subframe may be called a TTI, multiple consecutive subframes may be called a TTI, and one slot or one mini-slot may be called a TTI. In other words, at least one of a subframe and a TTI may be a subframe in existing LTE (1 ms), a period shorter than 1 ms (e.g., 1-13 symbols), or a period longer than 1 ms. Note that the unit representing a TTI may be called a slot, mini-slot, etc., instead of a subframe.

[0491] Here, TTI refers to, for example, the smallest time unit 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.

[0492] 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. When a TTI is given, the actual time interval (e.g., number of symbols) in which the transport block, code block, code word, etc. are mapped may be shorter than the TTI.

[0493] Furthermore, if one slot or one mini-slot is referred to as a TTI, then one or more TTIs (i.e., one or more slots or one or more mini-slots) may constitute the minimum time unit for scheduling. In addition, the number of slots (number of mini-slots) that constitute this minimum time unit for scheduling may be controlled.

[0494] A TTI with a time length of 1 ms may be called a normal TTI, long TTI, normal subframe, long subframe, slot, etc. A TTI shorter than a normal TTI may be called a shortened TTI, short TTI, partial or fractional TTI, shortened subframe, short subframe, mini slot, sub slot, slot, etc.

[0495] 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.

[0496] 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.

[0497] 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. One TTI, one subframe, etc., may each consist of one or more resource blocks.

[0498] One or more RBs may also be called Physical RBs (PRBs), Sub-Carrier Groups (SCGs), Resource Element Groups (REGs), PRB pairs, RB pairs, etc.

[0499] 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.

[0500] A Bandwidth Part (BWP), also known as a partial bandwidth, may represent a subset of consecutive common resource blocks (RBs) for a given neurology in a given carrier. These common RBs may be identified by an index of the RBs relative to a common reference point of the carrier. The PRBs may be defined and numbered within a given BWP.

[0501] A BWP may include UL BWP (BWP for UL) and DL BWP (BWP for DL). One or more BWPs may be configured within a single carrier for a UE.

[0502] At least one of the configured BWPs may be active, and the UE does not need to assume that it will transmit or receive a predetermined signal / channel outside of the active BWP. In this disclosure, terms such as "cell" and "carrier" may be read as "BWP".

[0503] The structures of wireless frames, subframes, slots, minislots, and symbols described above are merely examples. For example, the number of subframes included in a wireless frame, the number of slots per subframe or wireless frame, the number of minislots included in a slot, the number of symbols and RBs included in a slot or minislot, the number of subcarriers included in an RB, and the number of symbols, symbol length, and cyclic prefix (CP) length within the TTI can be varied in various ways.

[0504] 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.

[0505] The names used for parameters and other elements in this disclosure are not restrictive in any way. Furthermore, mathematical formulas and other elements using 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.

[0506] 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.

[0507] 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.

[0508] 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.

[0509] Any information described in this disclosure (e.g., variables, constants, parameters) may be communicated from any first device (e.g., UE / base station) to any second device (e.g., base station / UE) that indicates / specifies (or relates to) the value of such any information, even if not specifically stated in the embodiments described above.

[0510] 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.

[0511] 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 Elements (CEs).

[0512] 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).

[0513] The determination may be made by a value represented by one 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).

[0514] 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.

[0515] 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.

[0516] 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).

[0517] In this disclosure, terms such as “precoding,” “precoder,” “weight (precoding weight),” “quasi-co-location (QCL),” “transmission configuration indication state (TCI state),” “spatial relation,” “spatial domain filter,” “transmit power,” “phase rotation,” “antenna port,” “layer,” “number of layers,” “rank,” “resource,” “resource set,” “beam,” “beam width,” “beam angle,” “antenna,” “antenna element,” “panel,” “UE panel,” “transmitting entity,” and “receiving entity” may be used interchangeably.

[0518] In this disclosure, "antenna port" may be interpreted interchangeably with "antenna port for any signal / channel" (e.g., a Demodulation Reference Signal (DMRS) port). In this disclosure, "resource" may be interpreted interchangeably with "resource for any signal / channel" (e.g., a reference signal resource, an SRS resource, etc.). Resources may include time / frequency / code / spatial / power resources. Furthermore, a spatial domain transmit filter may include at least one of a spatial domain transmit filter and a spatial domain receive filter.

[0519] The above group may include, for example, at least one of the following: a spatial relationship group, a code division multiplexing (CDM) group, a reference signal (RS) group, a control resource set (CORESET) group, a PUCCH group, an antenna port group (e.g., a DMRS port group), a layer group, a resource group, a beam group, an antenna group, or a panel group.

[0520] Furthermore, in this disclosure, terms such as beam, SRS Resource Indicator (SRI), CORESET, CORESET pool, PDSCH, PUSCH, Codeword (CW), Transport Block (TB), and RS may be interpreted interchangeably.

[0521] Furthermore, in this disclosure, TCI state, downlink TCI state (DL TCI state), uplink TCI state (UL TCI state), unified TCI state, common TCI state, joint TCI state, etc., may be interpreted interchangeably.

[0522] Furthermore, in this disclosure, terms such as "QCL," "QCL assumption," "QCL relationship," "QCL type information," "QCL property / properties," "specific QCL type (e.g., Type A, Type D) properties," and "specific QCL type (e.g., Type A, Type D)" may be interpreted interchangeably.

[0523] In this disclosure, terms such as index, identifier (ID), indicator, indication, and resource ID may be interpreted interchangeably. In this disclosure, terms such as sequence, list, set, group, cluster, subset may be interpreted interchangeably.

[0524] Furthermore, the spatial relationship information Identifier (ID) (TCI state ID) and spatial relationship information (TCI state) may be interpreted as mutually exclusive. "Spatial relationship information (TCI state)" may be interpreted as mutually exclusive as "a set of spatial relationship information (TCI state)," "one or more pieces of spatial relationship information," etc. TCI state and TCI may be interpreted as mutually exclusive. Spatial relationship information and spatial relationship may be interpreted as mutually exclusive.

[0525] 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.

[0526] A base station may house one or more (e.g., three) cells. If a base station houses multiple cells, the entire coverage area of ​​the base station may 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.

[0527] In this disclosure, the transmission of information by a base station to a terminal may be interpreted as the base station instructing the terminal to perform a control / operation based on said information.

[0528] In this disclosure, terms such as "Mobile Station (MS)," "user terminal," "User Equipment (UE)," and "terminal" may be used interchangeably.

[0529] 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.

[0530] 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.

[0531] 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.

[0532] 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.

[0533] Figure 17 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.

[0534] 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.

[0535] 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).

[0536] 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 amount signals acquired by accelerator pedal sensor 55, brake pedal depression amount signals acquired by brake pedal sensor 56, operation signals of shift lever 45 acquired by shift lever sensor 57, and detection signals acquired by object detection sensor 58 for detecting obstacles, vehicles, pedestrians, etc.

[0537] 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, display, 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 (for example, multimedia information / multimedia services) to the occupants of the vehicle 40.

[0538] 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.) or output devices that perform output to the outside (e.g., display, speaker, LED lamp, touch panel, etc.).

[0539] 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.

[0540] 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.

[0541] 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).

[0542] 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 the information based on the above input.

[0543] 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).

[0544] 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.

[0545] 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 of the base station 10 described above. 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, downlink channel, etc., may be interpreted as sidelink channel.

[0546] 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.

[0547] 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 having base stations, it is clear that various operations performed for communication with terminals may be performed by the base station, one or more network nodes other than the base station (for example, a Mobility Management Entity (MME), a Serving Gateway (S-GW), etc., but not limited to these), or a combination thereof.

[0548] Each aspect / embodiment described in this disclosure may be used individually, in combination, or switched between as needed 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 using exemplary order and are not limited to the specific order presented.

[0549] Each aspect / embodiment described in this disclosure is 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®), IEEE 802.20, systems utilizing Ultra-WideBand (UWB), Bluetooth®, or other appropriate wireless communication methods, and next-generation systems extended, modified, created, or defined based thereon may also be applied. Furthermore, multiple systems may be applied in combination (for example, a combination of LTE or LTE-A and 5G).

[0550] 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."

[0551] 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.

[0552] The term “determining” as used in this disclosure may encompass a wide variety of actions. For example, “determining” may be considered to mean judging, calculating, computing, processing, deriving, investigating, looking up, searching, or inquiring (e.g., searching in tables, databases, or other data structures), ascertaining, etc.

[0553] 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).

[0554] Furthermore, “judgment (decision)” may be considered as “judgment (decision)” of resolving, selecting, choosing, establishing, comparing, etc. In other words, “judgment (decision)” may be considered as “judgment (decision)” of some action. In this disclosure, “judgment (decision)” may be interpreted as mutually interchangeable with the actions described above.

[0555] Furthermore, in this disclosure, “determine / determining” may be interpreted as “assume / assuming,” “expect / expecting,” or “consider / considering.” In addition, in this disclosure, “not expecting to do…” may be interpreted as “expecting not to do….”

[0556] In this disclosure, "expect" may be rephrased as "be expected." For example, "expect(s) ..." (where "..." may be expressed as a that clause, an infinitive, etc.) may be rephrased as "be expected ..." or "do (the verb without "to" if "..." is an infinitive)." Similarly, "does not expect ..." may be rephrased as "be not expected ..." or "do not (the verb without "to" if "..." is an infinitive)." Furthermore, "An apparatus A is not expected ..." may be rephrased as "An apparatus B other than apparatus A does not expect ... from apparatus A" (for example, if apparatus A is a UE, apparatus B may be a base station).

[0557] The term "maximum transmit power" as used in this disclosure may mean the maximum transmit power, the nominal UE maximum transmit power, or the rated UE maximum transmit power.

[0558] 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.”

[0559] 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, and optical (both visible and invisible) domain.

[0560] 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."

[0561] 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.

[0562] 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.

[0563] In this disclosure, terms such as "less than or equal to," "less than," "greater than or equal to," "more than," and "equal to" may be interpreted interchangeably. In addition, in this disclosure, terms meaning "good," "bad," "big," "small," "high," "low," "early," "slow," "wide," and "narrow" may be interpreted interchangeably, not limited to the positive, comparative, and superlative degrees. Furthermore, in this disclosure, terms meaning "good," "bad," "big," "small," "high," "low," "early," "slow," "wide," and "narrow" may be interpreted interchangeably, not limited to the positive, comparative, and superlative degrees, by adding "i-th" (where i is any integer) to the expression (for example, "highest" may be interpreted interchangeably as "i-th highest").

[0564] In this disclosure, "of," "for," "regarding," "related to," and "associated with" may be interpreted as being interchangeable.

[0565] In this disclosure, phrases such as "when A, B", "if A, then B", "B upon A", "B in response to A", "B based on A", "B during / while A", "B before A", "B at (the same time as) / on A", "B after A", "B since A", and "B until A" may be interchangeable. Furthermore, A, B, etc., may be replaced with appropriate expressions such as nouns, gerunds, or regular sentences depending on the context. The time difference between A and B may be approximately zero (immediately after or immediately before). Additionally, a time offset may be applied to the time when A occurs. For example, "A" may be interpreted as "before / after the time offset when A occurs". The time offset (e.g., one or more symbols / slots) may be predetermined or determined by the UE based on notified information.

[0566] In this disclosure, timing, time, duration, time instance, any unit of time (e.g., slot, subslot, symbol, subframe), period, occasion, resource, etc., may be interpreted interchangeably.

[0567] 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 descriptions herein are illustrative and not intended to be restrictive in any way to the invention described herein.

Claims

1. A terminal having a control unit that determines the positions of a first time domain and a frequency domain of a first channel state information reference signal (CSI-RS) to which a frequency density of less than 0.5 is applied, and the positions of a second time domain and a frequency domain of a second CSI-RS to which a frequency density of 0.5 or more is applied; and a receiving unit that receives at least one of the first CSI-RS transmitted at the positions of the first time domain and frequency domain and the second CSI-RS transmitted at the positions of the second time domain and frequency domain.

2. The terminal according to claim 1, wherein the control unit determines the position of the first time domain and the frequency domain and the position of the second time domain and the frequency domain using a plurality of parameter sets common to the first CSI-RS and the second CSI-RS.

3. The terminal according to claim 1, wherein the control unit determines the position of the first time domain and frequency domain using a first set of parameters, and determines the position of the second time domain and frequency domain using a second set of parameters different from the first set of parameters.

4. The terminal according to claim 1, wherein the control unit determines the frequency density applied to the first CSI-RS based on a plurality of parameter sets for determining the position of the second time domain and frequency domain, and a specific parameter.

5. A wireless communication method for a terminal, comprising the steps of: determining the positions of a first time domain and a frequency domain of a first channel state information reference signal (CSI-RS) to which a frequency density of less than 0.5 is applied, and the positions of a second time domain and a frequency domain of a second CSI-RS to which a frequency density of 0.5 or greater is applied; and receiving at least one of the first CSI-RS transmitted at the positions of the first time domain and a frequency domain, and the second CSI-RS transmitted at the positions of the second time domain and a frequency domain.

6. A base station having: a control unit that determines the positions of a first time domain and frequency domain of a first channel state information reference signal (CSI-RS) to which a frequency density of less than 0.5 is applied, and the positions of a second time domain and frequency domain of a second CSI-RS to which a frequency density of 0.5 or more is applied; and a transmitting unit that transmits at least one of the first CSI-RS at the positions of the first time domain and frequency domain and the second CSI-RS at the positions of the second time domain and frequency domain.

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