Method for reporting channel state information in a wireless communication system and apparatus therefor

Abstract

This invention provides a method and apparatus for reporting channel state information in a wireless communication system. The method includes: a UE receiving downlink control information (DCI) from a base station (BS) relating to an aperiodic CSI report to be performed by the UE in time slot n; and the UE determining a value n based on the number Z′ of symbols related to the time used to calculate the CSI. CQI_ref The time slot n-n is determined by the UE as the time domain to be used for aperiodic CSI reporting. CQI_ref The CSI reference resource; and the UE based on it as slot n-n CQI_ref The CSI reference resource sends non-periodic CSI reports to the BS in time slot n. According to the invention, CSI can be calculated using the most recent A CSI-RS, and thus the most recent CSI can be reported.

Description

[0001] This application is a divisional application of patent application No. 201880039017.4 (PCT / KR2018 / 014655), filed with the Chinese Patent Office on December 12, 2019, with an international application date of November 26, 2018, entitled "Method and Apparatus for Reporting Channel State Information in a Wireless Communication System". Technical Field

[0002] The present invention relates to wireless communication, and more particularly, to a method for reporting channel state information (CSI) and an apparatus for supporting the method. Background Technology

[0003] Mobile communication systems are typically developed to provide voice services while ensuring user mobility. These systems have gradually expanded their coverage from voice to data services, and eventually to high-speed data services. However, due to resource constraints in current mobile communication systems and users' demands for even faster services, there is a need to develop more advanced mobile communication systems.

[0004] The requirements for next-generation mobile communication systems may include supporting massive data traffic, significantly increased transmission rates per user, a substantial increase in the number of connected devices, very low end-to-end latency, and high energy efficiency. To this end, various technologies such as small cell enhancement, dual connectivity, massive MIMO, in-band full-duplex, non-orthogonal multiple access (NOMA), support for ultra-wideband, and device networking have been investigated. Summary of the Invention

[0005] Technical issues

[0006] One object of the present invention is to provide a method for determining CSI reference resources in relation to CSI reports.

[0007] The technical objectives to be achieved by this invention are not limited to those described above, and those skilled in the art can clearly understand other technical objectives not mentioned above from the description given below.

[0008] Technical solution

[0009] This document provides a method for transmitting and receiving CSI-RS in a wireless communication system.

[0010] More specifically, the method performed by the user equipment (UE) includes: the UE receiving downlink control information (DCI) from the base station (BS) relating to the aperiodic CSI reporting to be performed by the UE in time slot n; and the UE determining the value n based on the number Z′ of symbols related to the time used to calculate the CSI. CQI_refThe time slot nn, determined by the UE, will be used in the time domain for aperiodic CSI reporting. CQI_ref The CSI reference resource; and the UE based on it as a time slot nn CQI_ref The CSI reference resource sends non-periodic CSI reports to the BS in time slot n.

[0011] Furthermore, according to the present invention, n CQI_ref Is greater than or equal to The minimum value so that the time slot nn CQI_ref It meets the effective downlink time slot standard, and among them It is the floor function and It is the number of symbols in a time slot.

[0012] Furthermore, according to the present invention, the effective downlink time slot standard is based at least on (i) the number of symbols Z′ related to the time used to calculate CSI and (ii) the DCI processing time.

[0013] Furthermore, according to the present invention, It is equivalent to 14 symbols in one time slot.

[0014] Furthermore, the method according to the invention further includes: in CSI reference resources (slot nn) CQI_ref The system receives an aperiodic reference signal (CSI-RS) from the BS; determines the CSI based on the aperiodic CSI-RS; and generates an aperiodic CSI report based on the CSI.

[0015] Furthermore, the method according to the invention further includes: determining the number of symbols Z′ related to the time used to calculate the CSI based on the CSI complexity and subcarrier spacing.

[0016] Furthermore, according to the present invention, the number of symbols Z′ does not include DCI processing time.

[0017] Furthermore, according to the present invention, the value n is determined based on the number Z′ of symbols related to the time used to calculate CSI. CQI_ref This includes: determining the value n based on the number of symbols Z′ related to the time used to calculate CSI, and further based on the number of symbols in a time slot. CQI_ref .

[0018] Furthermore, according to the present invention, receiving DCI includes receiving DCI in a time slot other than the time slot n in which a non-periodic CSI report is to be performed.

[0019] Furthermore, according to the present invention, based on a value n equal to zero CQI_ref Non-periodic CSI reporting is performed in the same time slot as receiving DCI.

[0020] Furthermore, a user equipment (UE) configured to report channel state information (CSI) in a wireless communication system includes: a radio frequency (RF) module configured to transmit and receive radio signals; at least one processor; and at least one computer memory operatively connected to the at least one processor and storing instructions that, when executed, cause the at least one processor to perform operations including: receiving downlink control information (DCI) from a base station (BS) via the RF module in relation to an aperiodic CSI report to be performed by the UE in time slot n; and determining a value n by the UE based on the number Z′ of symbols related to the time used for calculating the CSI. CQI_ref The time slot nn, determined by the UE, will be used in the time domain for aperiodic CSI reporting. CQI_ref The CSI reference resource; and based on the time slot nn CQI_ref The CSI reference resource is used to send non-periodic CSI reports to the BS in time slot n via the RF module.

[0021] Beneficial effects

[0022] This invention identifies CSI reference resources that are as close as possible to the CSI reporting time, thereby preventing resources (a number of symbols) from being wasted and unused, and reports the most recent CSI by calculating the CSI based on the most recently received CSI-RS.

[0023] The technical effects of the present invention are not limited to those described above, and those skilled in the art will understand from the following description other technical effects not mentioned herein. Attached Figure Description

[0024] The accompanying drawings, which are included herein as part of the detailed description to aid in understanding the invention, provide embodiments of the invention, and the technical features of the invention are described using the following detailed description.

[0025] Figure 1 The diagram illustrates an example of the overall system architecture of an NR to which the methods proposed in this specification can be applied.

[0026] Figure 2 The diagram illustrates the relationship between uplink frames and downlink frames in a wireless communication system to which the methods proposed in this specification can be applied.

[0027] Figure 3 An example of a resource grid supported by a wireless communication system to which the methods proposed in this specification can be applied is illustrated.

[0028] Figure 4 An example of a self-contained subframe structure to which the methods proposed in this specification can be applied is illustrated.

[0029] Figure 5 The diagram illustrates a transceiver unit model in a wireless communication system to which the present invention can be applied.

[0030] Figure 6 This is a flowchart illustrating an example of a CSI-related process.

[0031] Figure 7 The illustration shows an example of timing for receiving periodic CSI-RS.

[0032] Figure 8 and 9 The illustration shows another example of timing for receiving periodic CSI-RS.

[0033] Figure 10 The illustration shows an example of a method for measuring CSI using AP CSI-RS.

[0034] Figure 11 The illustration shows an example of another method for measuring CSI using APCSI-RS.

[0035] Figure 12 This illustration shows an example of A-CSI report triggering for a single CSI, as proposed in this specification.

[0036] Figure 13 The illustration shows an example of A-CSI report triggering for a single CSI with periodic CSI-RS as proposed in this specification.

[0037] Figure 14 and 15 An example of the method proposed in this specification for determining the time offset of a CSI reference resource is illustrated.

[0038] Figure 16 The illustration shows an example of A-CSI report triggering for a single CSI with a non-periodic CSI-RS, as proposed in this specification.

[0039] Figure 17 This is a flowchart illustrating an example of a method for a UE to perform a CSI report as proposed in this specification.

[0040] Figure 18 This is a flowchart illustrating an example of the method proposed in this specification for an eNB to receive CSI reports.

[0041] Figure 19 The diagram illustrates the proposed implementation of n in this specification. CQI_ref An example of a value-based method.

[0042] Figure 20A block diagram of a wireless communication device to which the methods proposed in this specification can be applied is shown.

[0043] Figure 21 A block diagram of a communication device according to an embodiment of the present invention is shown.

[0044] Figure 22 An example of an RF module of a wireless communication device to which the methods proposed in this specification can be applied is illustrated.

[0045] Figure 23 Another example of an RF module of a wireless communication device to which the methods proposed in this specification can be applied is illustrated. Detailed Implementation

[0046] In the following, preferred embodiments of the invention will be described in detail with reference to the accompanying drawings. The detailed description disclosed below with reference to the drawings is intended to describe illustrative embodiments of the invention, but is not intended to represent the only embodiments of the invention. The following detailed description includes specific details for providing a complete understanding of the invention. However, those skilled in the art will understand that the invention can be practiced without introducing specific details.

[0047] In some cases, to avoid obscuring the gist of the invention, well-known structures and devices may be omitted, or well-known structures and devices may be depicted in the form of block diagrams relating to the core functions of each structure and device.

[0048] In this document, the base station is considered a terminal node of the network that performs direct communication with the UE. Specific operations considered to be performed by the base station in this document can be performed by upper-layer nodes of the base station as appropriate. In other words, it is evident that in a network consisting of multiple network nodes including the base station, various operations for communicating with the UE can be performed by the base station or network nodes other than the base station. The term base station (BS) can be replaced by terms such as fixed station, Node B, evolved Node B (eNB), base transceiver system (BTS), access point (AP), or general NB (gNB). Furthermore, the terminal can be fixed or mobile; and this term can be replaced by terms such as user equipment (UE), mobile station (MS), user terminal (UT), mobile subscriber station (MSS), subscriber station (SS), advanced mobile station (AMS), radio terminal (WT), machine-type communication (MTC) equipment, machine-to-machine (M2M) equipment, or device-to-device (D2D) equipment.

[0049] In the following text, downlink (DL) refers to communication from the base station to the terminal, while uplink (UL) refers to communication from the terminal to the base station. In downlink transmission, the transmitter can be part of the base station, and the receiver can be part of the terminal. Similarly, in uplink transmission, the transmitter can be part of the terminal, and the receiver can be part of the base station.

[0050] Specific terms are introduced in the following description to aid in understanding the invention, and these terms may be used in different ways as long as they do not depart from the technical scope of the invention.

[0051] The technologies described below can be used in various types of wireless access systems, including Code Division Multiple Access (CDMA), Frequency Division Multiple Access (FDMA), Time Division Multiple Access (TDMA), Orthogonal Frequency Division Multiple Access (OFDMA), Single Carrier Frequency Division Multiple Access (SC-FDMA), and Non-Orthogonal Multiple Access (NOMA). CDMA can be implemented using radio technologies such as Universal Terrestrial Radio Access (UTRA) or CDMA2000. TDMA can be implemented using radio technologies such as Global System for Mobile Communications (GSM), Universal Packet Radio Service (GPRS), or Enhanced Data Rate for GSM (EDGE). OFDMA can be implemented using radio technologies such as IEEE 802.11 (WiFi), IEEE 802.16 (WiMAX), IEEE 802-20, or evolved UTRA (E-UTRA). UTRA is part of the Universal Mobile Telecommunications System (UMTS). The 3rd Generation Partnership Project (3GPP) Long Term Evolution (LTE) is part of the Evolved UMTS (E-UMTS) using E-UTRA, which employs OFDMA for downlink and SC-FDMA for uplink transmission. LTE-A (Advanced) is an evolution of the 3GPP LTE system.

[0052] 5G NR defines enhanced mobile broadband (eMBB), massive machine-type communications (mMTC), ultra-reliable and low-latency communications (URLLC), and vehicle-to-the-world (V2X), depending on the use case.

[0053] Furthermore, based on the coexistence between NR and LTE systems, the 5G NR standard is divided into standalone (SA) and non-standalone (NSA) modes.

[0054] Furthermore, 5G NR supports various subcarrier spacings and supports CP-OFDM for downlink transmission, while CP-OFDM and DFT-s-OFDM (SC-OFDM) are used for uplink transmission.

[0055] Embodiments of the present invention can be supported by standard documents disclosed for at least one radio access system such as IEEE 802, 3GPP, and 3GPP2. In other words, the foregoing documents back up those steps or portions of the embodiments of the present invention that are not described to clearly illustrate the technical principles of the invention. Furthermore, all terms disclosed in this document can be described using the foregoing standard documents.

[0056] For clarity, the description is primarily given regarding 3GPP LTE / LTE-A, but the technical features of the present invention are not limited to any particular system.

[0057] Definition of terminology

[0058] eLTE eNB: eLTE eNB is an evolution of eNB that supports EPC and NGC connectivity.

[0059] gNB: In addition to connecting to NGC, it also supports NR nodes.

[0060] New RAN: Radio access networks that support NR, E-UTRA, or interaction with NGC.

[0061] Network slicing: Network slicing is a network defined by an operator to provide solutions optimized for specific market scenarios that require specific requirements and range between terminals.

[0062] Network function: A network function is a logical node in a network infrastructure that has a well-defined external interface and well-defined functional operations.

[0063] NG-C: Control plane interface for the NG2 reference point between the new RAN and NGC.

[0064] NG-U: User plane interface for NG3 reference points between the new RAN and NGC

[0065] Non-standalone NR: gNB requires an LTE eNB as the anchor point for the control plane connection to the EPC or requires an eLTE eNB as the anchor point for the control plane connection to the NGC.

[0066] Non-standalone E-UTRA: eLTE eNB requires gNB for deployment configuration as the anchor point for control plane connection to NGC.

[0067] User plane gateway: End point of NG-U interface

[0068] Parameter sets (Numerologies): These correspond to a subcarrier spacing in the frequency domain. Different parameter sets can be defined by scaling the reference subcarrier spacing by an integer N.

[0069] NR: NR radio access or new radio

[0070] General System

[0071] Figure 1 This is a block diagram illustrating an example of the overall structure of a new radio (NR) system that can implement the methods proposed in this disclosure.

[0072] refer to Figure 1 NG-RAN consists of gNBs used to provide NG-RA user plane (new AS sublayer / PDCP / RLC / MAC / PHY) and control plane (RRC) protocol terminals for UE (user equipment).

[0073] gNBs connect to each other via the Xn interface.

[0074] gNB also connects to NGC via the NG interface.

[0075] More specifically, the gNB connects to the Access and Mobility Management Function (AMF) via the n2 interface and to the User Plane Function (UPF) via the n3 interface.

[0076] NR (New RAT) parameter set and frame structure

[0077] In NR systems, multiple parameter sets can be supported. A parameter set can be defined by the subcarrier spacing and CP (cyclic prefix) overhead. The spacing between multiple subcarriers can be obtained by scaling the basic subcarrier spacing by an integer N (or μ). Furthermore, although it is assumed that very low subcarrier spacing is not used at very high subcarrier frequencies, the parameter set to be used can be selected regardless of the frequency band.

[0078] In addition, the NR system can support various frame structures based on multiple parameter sets.

[0079] The following section describes the set of orthogonal frequency division multiplexing (OFDM) parameters and frame structures that can be considered in NR systems.

[0080] Table 1 defines the multiple OFDM parameter sets supported by the NR system.

[0081] Table 1

[0082]

[0083] Regarding the frame structure in the NR system, the size of each field in the time domain is expressed as T. s =1 / (Δf) max ·N f A multiple of the time unit. In this case, Δfmax =480·10 3 and / N f =4096, DL and UL transmissions are configured to have T f =(Δf max N f / 100)·T s A radio frame consists of 10 ms segments. A radio frame is composed of ten subframes, each with a duration of T... sf =(Δf max N f / 1000)·T s =1ms portion. In this case, there are UL frame sets and DL frame sets.

[0084] Figure 2 The diagram illustrates the relationship between UL frames and DL frames in a wireless communication system that can implement the methods proposed in this disclosure.

[0085] like Figure 2 As shown, the UL frame number I from the user equipment (UE) needs to be sent before the start of the corresponding DL frame in the UE.

[0086] Regarding the parameter set μ, according to the subframe ascending order and according to the radio frame The time slots are numbered in ascending order. A time slot is composed of... Composed of consecutive OFDM symbols, and It is determined based on the parameter set and time slot configuration in use. The time slots in the subframe The start time is the same as the OFDM symbol in the same subframe. The beginning of the alignment.

[0087] Not all UEs can transmit and receive simultaneously, which means that not all OFDM symbols in the DL or UL slots are available.

[0088] Table 2 shows the number of OFDM symbols for each slot of the normal CP in parameter set μ, and Table 3 shows the number of OFDM symbols for each slot of the extended CP in parameter set μ.

[0089] Table 2

[0090]

[0091] Table 3

[0092]

[0093]

[0094] NR physical resources

[0095] Regarding physical resources in an NR system, one can consider antenna ports, resource grids, resource elements, resource blocks, carrier components, etc.

[0096] The physical resources described above that can be considered in an NR system will be described in more detail below.

[0097] First, regarding antenna ports, an antenna port is defined such that a channel through which a symbol on one antenna port is transmitted can be inferred from another channel through which a symbol on the same antenna port is transmitted. Two antenna ports can be in a QC / QCL (quasi-co-location or quasi-co-addressable) relationship when the large-scale properties of a channel through which a symbol on one antenna port is received can be inferred from the channel through which a symbol on another antenna port is transmitted. Here, large-scale properties can include at least one of delay spread, Doppler spread, Doppler shift, average gain, and average delay.

[0098] Figure 3 An example of a resource grid supported in a wireless communication system that can implement the methods proposed in this disclosure is illustrated.

[0099] refer to Figure 3 Resource grid is in the frequency domain The subframe is composed of subcarriers, and each subframe consists of 14.2 μ OFDM symbols, but this disclosure is not limited thereto.

[0100] In an NR system, the transmitted signal is transmitted through... Subcarriers and It is described by one or more resource grids composed of OFDM symbols. Here, above This represents the maximum transmission bandwidth, and it may vary not only between parameter sets, but also between UL and DL.

[0101] In this case, such as Figure 3 As shown, a resource grid can be configured for the parameter set μ and the antenna port p.

[0102] Each element of the resource grid for parameter set μ and antenna port p is indicated as a resource element and can be indexed by index pairs. A unique identifier. Here, It is an index in the frequency domain, and The position of the indicator symbol within the subframe. Index pairs are used to indicate resource elements within a time slot. Here,

[0103] Resource elements of parameter set μ and antenna port p With complex values Correspondingly, when there is no risk of confusion or when a specific antenna port or parameter set is specified, the indices p and μ can be discarded, thus allowing complex values ​​to be transformed. or

[0104] Additionally, physical resource blocks are defined in the frequency domain. A series of consecutive subcarriers. In the frequency domain, a physical resource block can range from 0 to... Numbering. At this time, the physical resource block number n PRB The relationship between (k,l) and resource elements can be given as Equation 1.

[0105] Equation 1

[0106]

[0107] Additionally, regarding the carrier portion, the UE can be configured to use only a subset of the resource grid to receive or transmit the carrier portion. In this case, the resource block set that the UE is configured to receive or transmit is in the frequency region from 0 to... Number 0.

[0108] Self-contained subframe structure

[0109] Figure 4 This is a diagram illustrating an example of a self-contained subframe structure that can be implemented in a wireless communication system according to the present disclosure.

[0110] To minimize data transmission latency in TDD systems, the new 5G RAT considers, for example... Figure 4 The self-contained subframe structure shown.

[0111] exist Figure 4 In the diagram, the diagonal area (symbol index 0) represents the UL control area, and the black area (symbol index 13) also represents the UL control area. Non-zero shaded areas can be used for either DL (deep learning) or UL (ultra-lowering) data transmission. This structure is characterized by sequentially performing DL and UL transmissions within a subframe, thus allowing for the transmission of DL data and the reception of UL ACK / NACK within the same subframe. In summary, this reduces the time required for retransmissions in case of data transmission errors and minimizes the delay in the final data transmission.

[0112] In this self-contained subframe structure, a time interval is required for the base station or UE to switch from transmit mode to receive mode or vice versa. Therefore, some OFDM symbols at the time points when switching from DL to UL in the self-contained subframe structure are configured as guard periods (GP).

[0113] Simulated beamforming

[0114] Because wavelengths are very short in the millimeter-wave (mmW) range, multiple antenna elements can be mounted in an area of ​​the same size. That is, the wavelength in the 30 GHz band is 1 cm, and therefore, 64 (8×8) antenna elements can be mounted in a two-dimensional arrangement with a wavelength of 0.5λ (i.e., wavelength) in a 4×4 (4 by 4) cm panel. Therefore, in the mmW range, coverage or throughput can be enhanced by increasing beamforming (BF) gain using multiple antenna elements.

[0115] In this scenario, to adjust the transmitted power and phase of each antenna element, independent beamforming could be performed on each frequency resource if a transceiver unit (TXRU) is included. However, installing a TXRU on each of approximately 100 antenna elements is uneconomical. Therefore, an approach is considered where multiple antenna elements are mapped to a single TXRU and the beam direction is adjusted using an analog phase shifter. This analog beamforming method can only form a single beam direction across the entire frequency band and suffers from the drawback of not allowing frequency-selective beamforming.

[0116] A hybrid beamforming system (BF) can be considered, which is an intermediate form between a digital BF and an analog BF and has B TXRUs with fewer than Q antenna elements. In this case, although the method used to connect the B TXRUs to the Q antenna elements varies, the beam directions that can be transmitted simultaneously are limited to less than B.

[0117] In the following description, a typical example of a method for connecting a TXRU to an antenna element will be given with reference to the accompanying drawings.

[0118] Figure 5 This is an example of a transceiver unit model that can be implemented in a wireless communication system according to this disclosure.

[0119] The TXRU virtualization model represents the relationship between the output signal from the TXRU and the output signal from the antenna element. Based on the relationship between the antenna element and the TXRU, the TXRU virtualization model can be categorized as TXRU virtualization model option-1: such as... Figure 5 (a) shows the subarray partitioning model; or it is classified as TXRU virtualization model option-2: fully connected model.

[0120] refer to Figure 5 (a) In the subarray partitioning model, the antenna element is divided into multiple antenna element groups, and each TXRU can be connected to one of the multiple antenna element groups. In this case, the antenna element is connected to only one TXRU.

[0121] refer to Figure 5(b) In the fully connected model, signals from multiple TXRUs are combined and sent to a single antenna element (or an arrangement of antenna elements). That is, this illustrates a method where a TXRU is connected to all antenna elements. In this case, the antenna element is connected to all TXRUs.

[0122] exist Figure 5 In this context, q represents the transmitted signal vector of an M common-polarized antenna element in a column. W represents the broadband TXRU virtualization weight vector, and W' represents the phase vector to be multiplied by the analog phase shifter. That is, the direction of the analog beamforming is determined by W. x represents the signal vectors of M_TXRU TXRUs.

[0123] Here, the mapping between antenna ports and TXRUs can be performed in a one-to-one or one-to-many manner.

[0124] Figure 5 The TXRU-to-element mapping in this example is merely an example, and this disclosure is not limited thereto, and can even be equivalently applied to the mapping of TXRUs and antenna elements that can be implemented in various hardware forms.

[0125] Channel State Information (CSI) Feedback

[0126] In most cellular systems, including LTE, the UE receives pilot signals (or reference signals) from the base station to estimate the channel, calculates channel state information (CSI), and reports the CSI to the base station.

[0127] The base station transmits data signals based on the CSI information fed back from the UE.

[0128] The CSI information fed back by the UE in the LTE system includes Channel Quality Information (CQI), Precoding Matrix Index (PMI), and Rank Indicator (RI).

[0129] CQI feedback is wireless channel quality information, which is provided to the base station to provide guidance (for link adaptation purposes) regarding which modulation and coding scheme (MCS) to apply when the base station transmits data.

[0130] When there is high-quality wireless communication between the base station and the UE, the UE can report a high CQI value, and the base station can transmit data by applying a relatively high modulation order and a low channel coding rate. Conversely, when there is high-quality wireless communication between the base station and the UE, the UE can report a low CQI value, and the base station can transmit data by applying a relatively low modulation order and a high channel coding rate.

[0131] PMI feedback is preferred precoding matrix information that is provided to the base station to provide guidance on which MIMO precoding scheme to apply when the base station has multiple antennas installed.

[0132] The UE estimates the downlink MIMO channel between the base station and the UE from the pilot signal, and recommends which MIMO precoding the base station wants to apply through PMI feedback.

[0133] In LTE systems, only linear MIMO precoding that can express PMI configurations in matrix form is considered.

[0134] The base station and the UE share a codebook consisting of multiple precoding matrices, and each MIMO precoding matrix in the codebook has a unique index.

[0135] Therefore, by feeding back the index corresponding to the most preferred MIMO precoding matrix in the codebook as the PMI, the UE minimizes the amount of feedback information.

[0136] The PMI value is not necessarily composed of a single index. For example, in an LTE system with eight transmitter antenna ports, the final 8tx MIMO precoding matrix can be obtained by combining only two indices (the first PMI and the second PMI).

[0137] RI feedback is information related to the number of preferred transmission layers. This information is provided to the base station to provide guidance on the number of preferred transmission layers for the UE when the base station and UE have installed multiple antennas to enable multi-layer transmission through spatial multiplexing.

[0138] RI and PMI are closely related. This is because the base station can determine which precoding needs to be applied to which layer based on the number of transport layers.

[0139] Regarding the configuration of PMI / RM feedback, a PMI codebook can be configured for a single layer of transport, and then a PMI can be defined and fed back for each layer. However, this method has the disadvantage that the amount of PMI / RI feedback information increases significantly with the increase in the number of transport layers.

[0140] Therefore, in LTE systems, the PMI codebook is defined based on the number of transport layers. That is, for R-layer transmission, N Nt×R matrices are defined (where R represents the layer number, Nt represents the number of transmitter antenna ports, and N represents the codebook size).

[0141] Therefore, in LTE, the size of the PMI codebook is defined regardless of the number of transport layers. As a result, because PMI / RI is defined in this structure, the number of transport layers (R) conforms to the rank of the precoding matrix (Nt×R matrix), and for this purpose, the term "rank indicator (RI)" is used.

[0142] Unlike PMI / RI in LTE systems, the PMI / RI described in this disclosure is not limited to representing the index value and rank value of the precoding matrix Nt×R.

[0143] The PMI indication described in this disclosure relates to information about a preferred MINO precoder among MIMO precoders that can be applied by the transmitter, and unlike in LTE systems, the form of the precoder is not limited to a linear precoder that can be expressed in matrix form. Furthermore, the RI described in this disclosure means wider than RO in LTE and includes feedback information for indicating the preferred number of transport layers.

[0144] CSI information can be obtained in all or some of the system frequency domains. Specifically, in wide-bandwidth systems, it may be useful to obtain CSI information in some preferred frequency domains (e.g., sub-bands) for each UE and then feed back the obtained CSI information.

[0145] In LTE systems, CSI feedback is performed via the UL channel, and periodic CSI feedback is typically performed via the Physical Uplink Control Channel (PUCCH), while aperiodic CSI feedback is performed via the Physical Uplink Shared Channel (PUSCH), which serves as the UL data channel.

[0146] Aperiodic CSI feedback means that feedback is sent only temporarily when the base station needs CSI feedback information, and the base station triggers CSI feedback through DL control channels such as PDCCH / ePDCCH.

[0147] In LTE systems, the information that a UE needs to report in response to a CSI feedback trigger is defined as the PUSCH CSI reporting mode, such as... Figure 8 As shown, and through higher-level messages to

[0148] The UE provides advance notification of the PUSCH CSI reporting mode in which the UE needs to perform an operation.

[0149] Channel State Information (CSI) Related Processes

[0150] In new radio (NR) systems, the Channel State Information Reference Signal (CSI-RS) is used for time / frequency tracking, CSI calculation, Layer 1 (L1)-Reference Signal Received Power (RSRP) calculation, or mobility.

[0151] Throughout this disclosure, “A and / or B” may be interpreted as the same as “including at least one of A or B”.

[0152] CSI calculation is related to CSI acquisition, and L1-RSRP calculation is related to beam management (BM).

[0153] CSI indicates all types of information used to indicate the quality of the radio channel (or link) formed between the UE and the antenna port.

[0154] The following section describes the UE's operation regarding CSI-related procedures.

[0155] Figure 6 This is a flowchart illustrating an example of a CSI-related process.

[0156] In order to perform one of the above-mentioned purposes of CSI-RS, the terminal (e.g., UE) receives CSI-related configuration information from the base station (e.g., general node B (gNB)) via radio resource control (RRC) signaling (S610).

[0157] CSI-related configuration information may include at least one of the following: CSI Interference Management (IM) resource information, CSI measurement configuration information, CSI resource configuration information, CSI-RS resource information, or CSI report configuration information.

[0158] CSIIM resource-related information may include CSI-IM resource information, CSI-IM resource set information, etc.

[0159] A CSI-IM resource set is identified by a CSI-IM resource set ID (identifier), and a resource set includes at least one CSI-IM resource.

[0160] Each CSI-IM resource is identified by a CSI-IM resource ID.

[0161] CSI resource configuration information defines a group that includes at least one of the following: a non-zero power (NZP) CSI-RS resource set, a CSI-IM resource set, or a CSI-SSB resource set.

[0162] In other words, CSI resource configuration information includes a list of CSI-RS resource sets, and the list of CSI-RS resource sets may include at least one of the NZP CSI-RS resource set list, the CSI-IM resource set list, or the CSI-SSB resource set list.

[0163] CSI resource configuration information can be represented as CSI-REsourceConfig IE.

[0164] A CSI-RS resource set is identified by a CSI-RS resource set ID, and a resource set includes at least one CSI-RS resource.

[0165] Each CSI-RS resource is identified by a CSI-RS resource ID.

[0166] As shown in Table 4, parameters can be set for each NZP CSI-RS resource set (e.g., BM-related parameter repetition and tracking-related parameter trs-Info used to indicate (or indicate) the purpose of CSI-RS).

[0167] Table 4 shows an example of an NZP CSI-RS resource set IE.

[0168] Table 4

[0169]

[0170]

[0171] In Table 4, the parameter repeat is a parameter used to indicate whether the same beam is transmitted repeatedly, and indicates whether repeat is set to "ON" or "OFF" for each NZP CSI-RS resource set.

[0172] The term “transmit (Tx) beam” as used in this disclosure may be interpreted as the same as a spatial domain transmit filter, and the term “receive (Rx) beam” as used in this disclosure may be interpreted as the same as a spatial domain receive filter.

[0173] For example, when the parameters in Table 4 are repeatedly set to "OFF", the UE does not assume that the NZP CSI-RS resources in the resource set across all symbols are sent to the same DL spatial domain transmission filter and the same Nrofports.

[0174] Additionally, the parameters corresponding to higher-level parameters are repeated in the L1 parameter "CSI-RS-ResourceRep".

[0175] CSI report configuration information includes the parameter `reportConfigType`, which indicates the time-domain behavior, and the parameter `reportQuantity`, which indicates the CSI-related quantities to be reported.

[0176] Temporal behavior can be periodic, aperiodic, or semi-persistent.

[0177] Additionally, CSI report configuration information can be represented as CSI-ReportConfig IE, and Table 5 shows an example of CSI-ReportConfig IE.

[0178] Table 5

[0179]

[0180]

[0181] In addition, the UE measures CSI based on configuration information related to CSI (S620).

[0182] Measuring CSI may include (1) the UE receiving CSI-RS (S621) and (2) calculating CSI based on the received CSI-RS (S622).

[0183] The CSI-RS sequence is generated using Equation 2, and the initial value of the pseudo-random sequence C(i) is defined using Equation 3.

[0184] Equation 2

[0185]

[0186] Equation 3

[0187]

[0188] In equations 2 and 3, It is the time slot number within the radio frame, and the pseudo-random sequence generator is initialized with Cint at the beginning of each OFDM symbol, where... It is the time slot number within a radio frame.

[0189] Additionally, l indicates the OFDM symbol number within the time slot, and n ID It indicates the scramblingID of higher-level parameters.

[0190] Additionally, regarding CSI-RS, resource element (RE) mapping of CSI-RS resources is performed in the time and frequency domains through the higher-level parameter CSI-RS-ResourceMapping.

[0191] Table 6 shows an example of the CSI-RS-ResourceMapping IE.

[0192] Table 6

[0193]

[0194]

[0195] In Table 6, density (D) indicates the density of CSI-RS resources measured in the RE / Port / Physical Resource Block (PRB), and nrofPorts indicates the number of antenna ports.

[0196] In addition, the UE reports the measured CSI to the base station (S630).

[0197] Here, when the quantity of CSI-ReportConfig in Table 6 is set to "None (or Do not report)," the UE can skip reporting.

[0198] However, even when the quantity is set to "none (or do not report)," the UE can still report the measured CSI to the base station.

[0199] The value is set to "none" when a non-periodic TRS is triggered or when repetition is set, in the case of t.

[0200] Here, it can be defined as omitting the UE's report only when repetition is set to "ON".

[0201] In short, when repetition is set to "ON" and "OFF", CSI reporting can indicate any of the following: "No Reporting", "SSB Resource Indicator (SSBRI) and L1-RSRP", and "CSI-RS Resource Indicator (CRI) and L1-RSRP".

[0202] Alternatively, it can be defined as sending a CSI report indicating "SSBRI and L1-RSRP" or "CRI and L1-RSRP" when repeat is set to "OFF", and it can be defined as sending a CSI report indicating "No Report", "SSBRI and L1-RSRP", or "CRI and L1-RSRP" when repeat is set to "ON".

[0203] CSI Measurement and Reporting Process

[0204] The NR system supports more flexible and dynamic CSI measurements and reporting.

[0205] CSI measurement may include receiving CSI-RS and obtaining CSI by calculating the received CSI-RS.

[0206] As a time-domain behavior for CSI measurement and reporting, it supports aperiodic / semi-persistent / periodic channel measurements (CM) and interference measurements (IM).

[0207] To configure CSI-IM, use the four-port NZP CSI-RS RE mode.

[0208] NR's CSI-IM-based IMR has a similar design to LTE's CSI-IM and is configured to be independent of the ZP CSI-RS resources used for PDSCH rate matching.

[0209] In addition, each port in the IMR based on NZP CSI-RS simulates an interference layer with (desired channel and) precoded NZPCSI-RS.

[0210] This is an in-cell interference measurement for multi-user scenarios, and it primarily targets MU interference.

[0211] On each port of the configured NZP CSI-RS-based IMR, the base station sends pre-coded NZP CSI-RS to the UE.

[0212] The UE assumes a channel / interference layer for each port in the resource set and measures the interference.

[0213] If there is no PMI or RI feedback for the channel, multiple resources are configured in the set, and the base station or network indicates a subset of NZP CSI-RS resources for channel / interference measurement via DCI.

[0214] The resource settings and resource configuration will be described in more detail.

[0215] Resource settings

[0216] Each CSI resource setting, "CSI-ResourceConfig", includes the configuration for S≥1 CSI resource sets (this is given by the higher-level parameter "csi-RS-ResourceSetList").

[0217] Here, the CSI resource settings correspond to CSI-RS-resourcesetlist.

[0218] Here, S represents the number of CSI-RS resource sets configured.

[0219] Here, the configuration of the S≥1CSI resource set includes each of the following CSI resource sets, which includes CSI-RS resources (consisting of NZP CSI-RS or CSI-IM) and SS / PBCH block (SSB) resources for L1-RSRP calculation.

[0220] Each CSI resource setting is located in the DL bandwidth portion (BWP) identified by the higher-level parameter bwp-id.

[0221] Additionally, all CSI resource settings linked to the CSI reporting settings have the same DL BWP.

[0222] In the CSI resource settings included in the CSI-ResourceConfig IE, the temporal behavior of CSI-RS resources can be indicated by the higher-level parameter resourceType and can be configured to be aperiodic, periodic, or semi-persistent.

[0223] The number S of CSI-RS resource sets configured for periodic and semi-persistent CSI resource settings is limited to "1".

[0224] The period and slot offsets configured for periodic and semi-persistent CSI resource settings are given from the parameter set of the relevant DL BWP, just as they are given by bwp-id.

[0225] When a UE is configured with multiple CSI-ResourceConfigs that include the same NZP CSI-RS resource ID, configure the same time-domain behavior for the CSI-ResourceConfigs.

[0226] When a UE is configured with multiple CSI-ResourceConfigs that have the same CSI-IM Resource ID, configure the same time-domain behavior for each CSI-ResourceConfig.

[0227] Subsequently, one or more CSI resource settings for channel measurement (CM) and interference measurement (IM) are configured via higher-level signaling.

[0228] - CSI-IM resources for interference measurement.

[0229] - NZP CSI-RS resources for interference measurements.

[0230] - NZP CSI-RS resources for channel measurements.

[0231] In other words, the channel measurement resource (CMR) can be an NZP CSI-RS for CSI acquisition, and the interference measurement resource (IMR) can be an NZP CSI-RS for both CSI-IM and IM.

[0232] Here, CSI-IM (or ZP CSI-RS for IM) is mainly used for inter-cell interference measurement.

[0233] In addition, the NZP CSI-RS for IM is mainly used for intra-cell interference measurements from multiple users.

[0234] The UE can assume that the CSI-RS resource and CSI-IM / NZPCSI-RS resource configured for interference measurement in a CSI report are “QCL-TypeD” for each resource.

[0235] Resource settings configuration

[0236] As mentioned above, resource settings can represent a list of resource sets.

[0237] Regarding aperiodic CSI, each trigger state configured using the higher-level parameter "CSI-AperiodicTriggerState" is associated with one or more CSI-ReportConfigs linked to periodic, semi-persistent, or aperiodic resource settings for each CSI-ReportConfig.

[0238] A report setting can be connected to up to three resource settings.

[0239] - When a resource setting is configured, the resource setting (given by the higher-level parameter resourcesForChannelMeasurement) relates to the channel measurements used for L1-RSRP calculation.

[0240] - When two resource settings are configured, the first resource setting (given by the higher-level parameter resourcesForChannelMeasurement) is used for channel measurements and the second resource setting (given by csi-IM-ResourcesForInterference or nzp-CSI-RS-ResourcesForInterference) is used for CSI-IM or for interference measurements performed on NZP CSI-RS.

[0241] - When three resource settings are configured, the first resource setting (given by resourcesForChannelMeasurement) is used for channel measurements, the second resource setting (given by csi-IM-ResourcesForInterference) is used for CSI-IM-based interference measurements, and the third resource setting (given by nzp-CSI-RS-ResourcesForInterference) is used for NZP-CSI-RS-based interference measurements.

[0242] Regarding semi-persistent or periodic CSI, each CSI-ReportConfig is linked to a periodic or semi-persistent resource setting.

[0243] - When a resource setting is configured (given by resourcesForChannelMeasurement), the resource setting relates to the channel measurements used for L1-RSRP calculation.

[0244] - When two resource settings are configured, the first resource setting (given by resourcesForChannelMeasurement) is used for channel measurements, and the second resource setting (given by the higher-level parameter "csi-IM-ResourcesForInterference") is used for interference measurements performed on CSI -IM.

[0245] The CSI calculations related to CSI measurements will be described in more detail.

[0246] If interference measurements are performed on CSI-IM, each CSI-RS resource used for channel measurements is associated with the CSI-RS resources in the corresponding resource set through the order of CSI-RS resources and CSI-IM resources.

[0247] The number of CSI-RS resources used for channel measurements is the same as the number of CSI-IM resources.

[0248] Additionally, when performing interference measurements on NZP CSI-RS, it is not expected that the UE will have one or more NZP CSI-RS resources configured in the relevant resource set within the resource settings used for channel measurements.

[0249] UEs configured with the higher-level parameter nzp-CSI-RS-ResourcesForInterference do not expect to be configured with 18 or more NZP CSI-RS ports in the NZPCSI-RS resource set.

[0250] For CSI measurements, the UE assumes the following.

[0251] - Each NZP CSI-RS port configured for interference measurement corresponds to the interference transmission layer.

[0252] - For interference measurements, each interference transmission layer of the NZP CSI-RS port considers the energy per resource element (EPRE) ratio.

[0253] - Different interference signals on the RE of the NZP CSI-RS resource for channel measurement, the NZP CSI-RS resource for interference measurement, or the CSI-IM resource for interference measurement.

[0254] The CSI reporting process will be described in more detail.

[0255] For CSI reports, the time and frequency resources available to the UE are controlled by the base station.

[0256] CSI can include 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), or L1-RSRP.

[0257] Regarding CQI, PMI, CRI, SSBRI, LI, RI, and L1-RSRP, the UE can be configured at a higher layer with N≥1 CSI-ReportConfig reporting settings, M≥1 CSI-ResourceConfig resource settings, and a list of one or two trigger states (provided by aperiodicTriggerStateList and semiPersistentOnPUSCH-TriggerStateList).

[0258] In aperiodicTriggerStateList, each trigger state includes a channel and a list of associated CSI-ReportConfigs for selectively indicating the resource set ID used for interference.

[0259] In the semiPersistentOnPUSCH-TriggerStateList, each trigger state includes an associated CSI-ReportConfig.

[0260] In addition, the time-domain behavior of CSI reports supports periodic, semi-persistent, and non-periodic CSI reports.

[0261] The following sections will describe periodic, semi-permanent, and non-periodic CSI reports.

[0262] Perform periodic CSI pre-classification on short and long PUCCHs.

[0263] The period and slot offset of periodic CSI reports can be configured by RRC and refer to CSI-ReportConfigIE.

[0264] Subsequently, SP CSI reports are executed for short PUCCH, long PUCCH, or PUSCH.

[0265] In the case of SP CSI on short / long PUCCH, the period and slot offset are configured by RRC, and CSI reporting for additional MAC CE is activated / deactivated.

[0266] In the case of SP CSI on PUSCH, the period of SP CSI reporting is configured by RRC, but its slot offset is not configured by RRC and SP CSI reporting is activated / deactivated by DCI (format 0_1).

[0267] The first CSI report timing follows the PUSCH time domain allocation value indicated by the DCI, and subsequent CSI report timing follows the period configured by the RRC.

[0268] For SP CSI reports on PUSCH, use the independent RNTI (SP-CSI C-RNTI).

[0269] DCI format 0_1 ​​can include a CSI request field and activate / deactivate SP-CSI triggering states for specific configurations.

[0270] Additionally, SP CSI reporting is activated / deactivated in the same or similar manner as the mechanism for data transmission on SPS PUSCH.

[0271] Next, perform a non-periodic CSI report on PUSCH, triggered by DCI.

[0272] In the case of AP CSI with AP CSI-RS, the AP CSI-RS timing is configured by RRC.

[0273] Here, the timing of AP CSI reports is dynamically controlled by the DCI.

[0274] The reporting method for segmenting and reporting CSI across multiple reporting instances (e.g., sending in the order of RI, WB, PMI / CQI, and SBPMI / CQI) is not used in NR for PUCCH-based CSI reporting, as is the method used in LTE.

[0275] Conversely, NR restricts the configuration of specific CSI reports on short / long PUCCH and defines CSI omission rules.

[0276] Regarding AP CSI reporting timing, the DCI dynamically indicates the PUSCH symbol / slot position. Additionally, the RRC configures the candidate slot offset.

[0277] Regarding CSI reports, configure slot offset (Y) for each report.

[0278] Regarding UL-SCH, configure slot offset K2 separately.

[0279] Two CSI latency classes (low latency class and high latency class) are defined based on the computational complexity of CSI.

[0280] Low-latency CSI is WB CSI, which includes up to 4 ports of Type I codebook or up to 4 ports of non-PMI feedback CSI.

[0281] High-latency CSI is a type of CSI other than low-latency CSI.

[0282] For ordinary UEs, (Z, Z') are defined in units of OFDM symbols.

[0283] Z represents the minimum CSI processing time after receiving a CSI-triggered DCI and before executing a CSI report.

[0284] Z' represents the minimum CSI processing time after receiving the CSI-RS related to the channel / interference and before executing the CSI report.

[0285] In addition, the number of CSIs that the UE report can calculate simultaneously.

[0286] The A-CSI or AP CSI used in this specification indicate the following non-periodic CSI, which is the CSI reported non-periodicly by the UE.

[0287] Furthermore, a CSI report or a CSI report as used in this specification may be considered to have the same meaning.

[0288] To inform the UE of its capabilities for A-CSI calculation or calculation time, the UE reports to the eNB the supported Z values ​​and the set of CSI configurations that can be supported for each Z value.

[0289] Here, Z is defined by the minimum required number of symbols for CSI computation for a given CSI configuration.

[0290] More specifically, Z refers to the minimum amount of time required for calculations related to AP CSI processing, such as decoding time, channel measurement, CSI calculation, and TX preparation.

[0291] CSI configuration includes: information indicating wideband (WB) CSI or subband (SB) and WB CSI; information related to the maximum number of CSI-RS ports; and information related to type 1 or type 2 codebooks.

[0292] When the UE supports multiple parameter sets, it can report CSI-related information for each parameter set.

[0293] When an A-CSI report is triggered in slot n on the PUSCH, the UE discards the A-CSI report in the following cases:

[0294] The time interval between the last symbol of the PDCCH and the start symbol of the PUSCH in slot n is less than the reported value of Z for a given CSI configuration, and

[0295] - The case where AP CSI-RS resources are sent from time slot n and the time interval between the last symbol of the CSI-RS resource and the start symbol of the PUSCH is less than the reported value of Z for a given CSI configuration.

[0296] Furthermore, the Z symbols preceding the start symbol of PUSCH and those between the start symbol of PUSCH are invalid as (CSI) reference resources.

[0297] The following section describes the triggering of A-CSI reports and related CSI reports.

[0298] When the eNB triggers the transmission of downlink control information (DCI) in time slot n

[0299] When an A-CSI report is received, the UE should perform the following actions.

[0300] The UE sends A-CSI via the PUSCH, which is allocated as a resource by the DCI.

[0301] The transmission timing of PUSCH is indicated by a specific field of DCI (which is defined as the Y value).

[0302] More specifically, PUSCH is sent from the (n+Y)th time slot (time slot n+Y) with reference to the time slot n corresponding to the trigger time of the A-CSI report.

[0303] For example, when the DCI field of the Y value is defined by 2 bits, the Y values ​​of 00, 01, 10, and 11 are defined by RRC signaling, and more specifically, are defined within the report settings defined by RRC signaling.

[0304] Reporting settings can also be represented through report settings or CSI-ReportConfig.

[0305] A-CSI report triggering can trigger one or more specific report settings, and define the values ​​of 00, 01, 10, and 11 of the DCI field based on the Y value defined within the triggered report setting.

[0306] As described above, when the time interval or timing interval between the last symbol of the PDCCH and the start symbol of the PUSCH is less than the Z value corresponding to the CSI configuration of the triggered A-CSI, the UE will send the triggered A-CSI to the eNB without discarding or updating the A-CSI.

[0307] Because the amount of time allocated for actual calculation is less than the minimum amount of time Z required to calculate A-CSI, the UE cannot calculate A-CSI.

[0308] As a result, the UE will not discard or update the triggered CSI.

[0309] When the non-zero power (NZP) CSI-RS or zero power (ZP) CSI-RS used for channel estimation or interference estimation of the triggered A-CSI is an aperiodic CSI-RS, the UE estimates the channel or interference by a single measurement from the corresponding RS.

[0310] In other words, it indicates that the UE estimates the channel or interference only by using the corresponding RS (NZP CSI-RS or ZP CSI-RS).

[0311] At this time, if the time interval between the last symbol of the CSI-RS resource and the start symbol of the PUSCH is less than the Z value corresponding to the CSI configuration of the triggered A-CSI, the UE will send the corresponding A-CSI to the eNB in ​​the same way as the UE operation described above, without discarding or updating the corresponding A-CSI.

[0312] Furthermore, when the UE calculates the CSI, it does so by assuming that it receives data from a specific frequency and / or time resource area (which is referred to as the CSI reference resource).

[0313] CSI reference resources can be simply referred to as reference resources.

[0314] Because the UE starts CSI calculation from the CSI reference resource time, the UE can only calculate CSI if it ensures that the amount of time is as long as that from the CSI reference resource time.

[0315] Therefore, the reference resource time must be defined at least z symbols (or z+1 symbols) before the CSI reporting time.

[0316] Therefore, when checking the validity of a reference resource, a symbol or time slot preceding at least z symbols (or z+1 symbols) is determined to be valid with respect to the CSI reporting time, otherwise it is invalid.

[0317] Here, reference resources (CSI) are defined in units of time slots.

[0318] In addition, referring to the time slots used for CSI reporting (e.g., time slot n), the number less than or equal to nn will be... CQI_ref The time slot (i.e., time slot nn) CQI_ref It has been identified as a (CSI) reference resource.

[0319] The statement above (which indicates that 'a symbol or time slot preceding at least z symbols (or z+1 symbols) is valid for the CSI reporting time, otherwise invalid') can indicate n CQI_ref It is configured by the following equation 4.

[0320] [Equation 4]

[0321]

[0322] In equation 4, round down, discarding digits after the decimal point, and denote the sign. To express.

[0323] UE sets its quantity to be less than or equal to nn CQI_ref The nearest time slot that meets the validity conditions of the reference resource is set as the reference resource.

[0324] Similarly, the UE can simply use time slot nn CQI_ref Set as a reference resource.

[0325] Furthermore, the time offset of the CSI reference resource can be determined based on Proposal 3, which will be described below, and Proposal 3 will provide a detailed description of how to determine the time offset of the CSI reference resource.

[0326] The A-CSI report trigger field included in DCI can be interpreted as follows.

[0327] When the eNB instructs the UE to perform A-CSI triggering for multiple reporting settings simultaneously, and the definition of the Y value is not simultaneous for each reporting setting, the following problem occurs, and UE operations to resolve the problem through various methods will be described.

[0328] For example, suppose report setting 1 is defined as Y = {0, 1, 2, 3}, and report setting 2 is defined as Y = {1, 2, 3, 4}.

[0329] In this case, ambiguity arises, where the value of the (2-bit) DCI field indicating the Y value must be interpreted.

[0330] Therefore, in order to eliminate this ambiguity, it is recommended that the UE operate according to the following method.

[0331] (Method 1)

[0332] The UE generates a new Y' as the intersection between two different Ys and interprets the DCI field based on the Y' value.

[0333] In other words, in the example above, the intersection of two different Ys is {1, 2, 3}, and the UE interprets 00, 01, 10, 11 in the DCI field as 1, 2, 3, 3 respectively.

[0334] If the intersection of two different Ys is {1}, then UE will interpret 00, 01, 10, 11 as 1, 1, 1, 1 respectively.

[0335] If the intersection of two different Ys is {1, 2}, then UE will interpret 00, 01, 10, 11 as 1, 2, 2, 2.

[0336] In the example above, when the number of elements belonging to the intersection between two different Ys is less than the state of the DCI field (e.g., 00, 01, 10, 11), the remaining state is defined by repeating the last intersection value.

[0337] However, unlike the above definition, the remaining state can be defined as retained.

[0338] (Method 2)

[0339] The UE interprets the DCI field based on the Y value defined in one of several reporting settings.

[0340] For example, in multiple reporting settings, the UE interprets the DCI field by using the Y value of the reporting setting with a low reporting setting index.

[0341] Similarly, in multiple reporting settings, the UE interprets the DCI field by using the Y value of the reporting setting with a low index of component carrier (CC).

[0342] The UE prioritizes the report setting index over the CC index and determines the Y value of the report setting by using the CC index.

[0343] If the CC indexes are the same, the UE can then determine the Y value based on the report setting index.

[0344] Alternatively, as mentioned above, the priority can be reversed (set the index for the report to have a higher priority).

[0345] (Method 3)

[0346] The UE may expect multiple reporting settings to always have the same Y value.

[0347] In other words, the eNB configures report settings 1 and 2 to have the same Y value via RRC signaling.

[0348] For example, an eNB can configure reporting setting 1 using Y = {1, 2, 3, 4} and reporting setting 2 using Y = {1, 2, 3, 4}.

[0349] (Method 4)

[0350] The UE determines the time offset of the non-periodic CSI report by using the larger of two different Y values.

[0351] For example, report setting 1 can be defined by Y1 = {0, 1, 2, 3}, and report setting 2 can be defined by Y2 = {1, 2, 3, 4}.

[0352] When the DCI field of Y (e.g., 2 bits) is '00', Y1 = 0 and Y2 = 1; and therefore, the value of Y is determined by '1', which is the larger of the two values.

[0353] When the DCI field of Y (e.g., 2 bits) is '01', Y1 = 1 and Y2 = 2; therefore, the value of Y is determined by '2', which is the larger of the two values.

[0354] When the DCI field values ​​are “10” and “11”, the Y values ​​can be defined in the same way as above, and the Y values ​​of the DCI field values ​​of “10” and “11” can be determined as “3” and ’4” respectively.

[0355] If three Y values ​​are defined, the largest of the three values ​​can be determined as the time offset by applying the same method as described above.

[0356] As described above, the eNB can instruct the UE to perform AP CSI report triggering via a DCI, and determine the time offset of the non-periodic CSI report according to the methods described above (methods 1 to 4) by using the Y value defined by the AP CSI report settings for each N-triggered report.

[0357] Additionally, the eNB can indicate the data transfer time via PUSCH while simultaneously executing AP CSI report triggering through the same DCI.

[0358] At this point, the data transmission time via PUSCH is defined as the "K2" value, and multiple candidate sets are pre-set to the UE via upper-layer signaling.

[0359] One of the candidate sets is determined (or selected) as the final K2 value by using the DCI field (also known as the "timing offset field").

[0360] Furthermore, the DCI field used to select the K2 value and the DCI field used to select the Y value are not defined by separate fields, but by the same DCI field.

[0361] When an AP CSI report is triggered, the UE uses the corresponding DCI field to select the Y value, and when a PUSCH data dispatch occurs, it uses the corresponding DCI field to select the K2 value.

[0362] When PUSCH data scheduling occurs simultaneously with the execution of AP CSI report triggering via DCI, ambiguity arises regarding whether each value of the timing offset field should be defined as a candidate for either the Y value or the K2 value.

[0363] To resolve this ambiguity, the methods described above (methods 1 to 4) can be directly extended and applied.

[0364] In other words, the proposed methods (methods 1 to 4) above concern how to define the value of the timing offset field when multiple Y candidate sets are given, and methods 1 to 4 can also be applied to the K2 candidate set by treating the K2 candidate set as a Y candidate set.

[0365] For example, method 4 can be extended and applied as described below.

[0366] The UE defines the timing offset field by using the larger of different Y and K2 values.

[0367] For example, suppose report setting 1 is defined as Y1 = {0, 1, 2, 3}, and report setting 2 is defined as K2 = {3, 4, 5, 6}.

[0368] If the DCI field of the timing offset is '00', then Y1 = 0, Y2 = 1, and K2 = 3; therefore, the timing offset field is determined by the maximum value '3'.

[0369] If the DCI field is '01', then Y1 = 1, Y2 = 2, and K2 = 4; and therefore, the timing offset field is determined by the maximum value '4'.

[0370] The DCI field values ​​for “10” and “11” can be determined in the same way, and in this case, the DCI field values ​​for “10” and “11” are determined to be “5” and “6”, respectively.

[0371] The UE can multiplex PUSCH data and CSI in a time slot (n + timing offset) relative to the time slot n where DCI has been received, based on the indicated DCI value, and simultaneously report (or send) the multiplexed data and CSI to the eNB.

[0372] Now, other methods besides those described above (methods 1 to 4) for interpreting A-CSI report triggers related DCI fields will be described.

[0373] (Method 5)

[0374] In another approach, the UE constructs a union by combining different candidate sets of Y and candidate sets of K2, and defines the value of the n-bit timing offset DCI field as ranging from the largest element of the union to the 2nth largest element.

[0375] The UE can multiplex PUSCH data and CSI in a time slot (n + timing offset) relative to the time slot n where DCI has been received, based on the indicated DCI value, and simultaneously report (or send) the multiplexed data and CSI to the eNB.

[0376] (Method 6)

[0377] In another approach, after constructing a set from the candidate set of Y using methods 1 to 4, a union is constructed by combining one of the candidate sets of Y with the candidate set of K2.

[0378] Furthermore, the DCI field value of the n-bit timing offset is defined by its range from the largest element of the union to the 2nth largest element.

[0379] (Method 7)

[0380] Method 7 constructs a set from the candidate set of Y using methods 1 to 4 and defines the i-th value of the DCI field of the timing offset by using the sum of the i-th element of one of the candidate sets of Y and the i-th element of the candidate set of K2.

[0381] For example, when the Y candidate set is {1, 2, 3, 4} and the K2 candidate set is {5, 6, 7, 8}, the individual values ​​of the 2-bit timing offset DCI field of 00, 01, 10, 11 can be defined by 1+5(6), 2+6(8), 3+7(10), and 4+8(12).

[0382] (Method 8)

[0383] Method 8 constructs a set from the candidate set of Y using methods 1 to 4 and defines the i-th value of the timing offset DCI field as the sum of the i-th elements of the candidate set of Y, while ignoring the candidate set of K2.

[0384] Next, the relaxation method used for AP CSI calculation will be described.

[0385] The UE reports the Z value as defined below to the eNB using one of the UE's capabilities used for AP CSI calculation.

[0386] By assuming that CSI is only PUSCH (without HARQ ACK / NACK) for a given set of parameters and CSI complexity, Z is defined as the minimum number of symbols required for receiving the DCI that triggers the CSI report, the PDCCH detection / decoding time, the channel estimation time, and the CSI calculation time.

[0387] For low-complexity CSI, a Z value is defined for a given set of parameters as shown in Table 7 below.

[0388] Furthermore, for high-complexity CSI, a Z value is defined for a given set of parameters as shown in Table 7 below.

[0389] [Table 7]

[0390] CSI complexity unit 15kHz SCS 30kHz SCS 60kHz SCS 120kHz SCS Low-complexity CSI symbol Z1，1 Z1，2 Z1，3 Z1，4 High-complexity CSI 1 symbol Z2，1 Z2，2 Z2，3 Z2，4 High-complexity CSI 2 symbol ZN+1, 1 ZN+1,2 ZN+1, 3 ZN+1, 4

[0391] As mentioned above, Z is defined as the sum of the time required for DCI decoding (which refers to the decoding time of the DCI that holds the AP CSI trigger information), the time required for channel estimation, and the time required for CSI.

[0392] Based on the complexity of the CSI triggered for the Z value, the eNB indicates the Y value (in other words, based on whether it is a low-complexity CSI or a high-complexity CSI).

[0393] If we assume that the DCI triggered by AP CSI (i.e., AP CSI-triggered DCI) is sent to time slot n, then the UE reports the corresponding CSI to the eNB in ​​time slot (n + timing offset Y).

[0394] If the time allocated to the UE for CSI calculation is insufficient for the UE's ability to calculate AP CSI, instead of updating (or calculating) the CSI, the UE sends the most recently reported CSI or any CSI (or a predefined specific CSI, such as CQI=0, PMI=0, and RI=1) to the eNB.

[0395] Figure 7 This explains the situation described above. In other words, Figure 7 The diagram illustrates the timing of receiving periodic CSI-RS signals.

[0396] More specifically, Figure 7 The diagram illustrates a situation where the most recent periodic (P)CSI-RS was received at or before the reference resource time within the time period T.

[0397] exist Figure 7 In this process, the UE measures CSI through periodic CSI-RS (P CSI-RS) and can note that there are P CSI-RS and CSI reference resources within time T.

[0398] In this case, within time T, the UE performs all DCI decoding, channel estimation, and CSI calculation.

[0399] Therefore, the UE compares T and Z, and if T < Z, it does not calculate (or update) CSI, but instead transmits the most recently reported CSI or any CSI.

[0400] If T >= Z, the UE calculates CSI based on the periodic CSI-RS and reports the calculated CSI to the eNB.

[0401] Figure 8 and 9 illustrates another example of the timing for receiving periodic CSI-RS.

[0402] In other words, Figure 8 and 9 illustrates a situation where there is a most recent P CSI-RS received at or before the reference resource time prior to the T period.

[0403] Or, Figure 8 and 9 illustrates a situation where there is no P CSI-RS within the T period but there is a P CSI-RS prior to the T period.

[0404] In other words, referring to Figure 8 and 9 , the UE has performed channel measurements from the (periodic) CSI-RS before the CSI reporting trigger occurs.

[0405] Therefore, in this case, the UE performs DCI decoding and CSI calculation within the T period.

[0406] The UE compares T and Z - (channel estimation time), and if T < Z - (channel estimation time), it does not calculate (or update) CSI, but instead sends the most recently reported CSI or any CSI to the eNB.

[0407] Here, the UE can report the channel estimation time to the eNB by using a separate capability.

[0408] If T >= Z - (channel estimation time), the UE calculates CSI and reports the calculated CSI to the eNB.

[0409] Here, Z - (channel estimation time) can be defined by a third variable Z', and the UE can report Z and Z' to the eNB separately.

[0410] Figure 10 illustrates an example of a method for measuring CSI by using AP CSI-RS.

[0411] First, the AP CSI-RS is defined to always exist within a time period T.

[0412] In this case, within time T, the UE performs all DCI decoding, channel estimation, and CSI calculation.

[0413] Therefore, the UE compares T and Z, and if T < Z, it does not calculate (or update) CSI, but instead transmits the most recently reported CSI or any CSI.

[0414] If T >= Z, the UE calculates CSI and reports the calculated CSI to the eNB.

[0415] Figure 11 An example of another method for measuring CSI by using the AP CSI-RS is illustrated.

[0416] More specifically, Figure 11 The case where the AP CSI-RS is transmitted long after the UE finishes decoding the DCI is illustrated.

[0417] In this case, the UE must perform all DCI decoding, channel estimation, and CSI calculation within the time period T.

[0418] However, because the AP CSI-RS is transmitted long after the DCI decoding is completed, the UE cannot perform channel measurement and CSI calculation during the time period T until the DCI decoding is completed and the AP CSI-RS is transmitted.

[0419] Therefore, the UE compares T and Z and if T < Z, it does not calculate (or update) CSI, but instead can transmit the most recently reported CSI or any CSI to the eNB; however, if T >= Z, the UE cannot calculate CSI and thus cannot report CSI to the eNB.

[0420] Therefore, in order for Figure 11 the method shown to be effective, the eNB must transmit the AP CSI-RS within the DCI decoding time after the last OFDM symbol that triggers the DCI.

[0421] Or the eNB must transmit the AP CSI-RS before Z - (decoding time) at the first OFDM symbol from which it reports the AP CSI.

[0422] The UE can report the decoding time to the eNB through a separate capability.

[0423] Here, Z - (decoding time) can be defined as a third variable Z', and the UE can report Z and Z' to the eNB separately.

[0424] In other words, if the time T' between the time when the AP CSI-RS for channel measurement or interference measurement is last received and the start time of reporting CSI is less than Z', the UE determines that the time for calculating CSI is insufficient and does not calculate CSI.

[0425] Therefore, instead of reporting valid CSI to the eNB, the UE reports a predefined pseudo-CSI value (e.g., RI = 1, PMI = 1, and CQI = 1).

[0426] Alternatively, if the time T' between the last OFDM symbol for transmitting the AP CSI-RS and the first OFDM symbol for reporting the AP-CSI is less than Z - (decoding time), the UE does not calculate (or update) CSI but transmits the most recently reported CSI or any CSI to the eNB.

[0427] And if T' >= Z - (decoding time) and T < Z, the UE does not calculate (or update) CSI but transmits the most recently reported CSI or any CSI.

[0428] If T' >= Z - (decoding time) and T >= Z, the UE calculates CSI and reports the calculated CSI to the eNB.

[0429] The UE can report the decoding time to the eNB through a separate capability.

[0430] Different from the proposals described later, if Z' is introduced, Z in Proposals 2 and 3 can be replaced by Z'.

[0431] As described above, Z indicates the minimum time required for all calculations related to AP CSI processing such as DCI decoding time, channel measurement, CSI calculation, and TX preparation.

[0432] And Z' indicates the minimum time required for channel measurement, CSI calculation, and TX preparation.

[0433] Therefore, referring to Z' which does not include the decoding time, it may preferably be set to the time provided by the UE, which spans from the last reception time of the CSI-RS for channel measurement or interference measurement to the start time of transmitting CSI.

[0434] The following Proposals 2 and 3 can be restricted (or limited) to the case of reporting CSI within a short period after the CSI reporting trigger.

[0435] For example, Proposals 2 and 3 described later can only be applied to cases with small Y values such as Y = 0 (or Y = 1).

[0436] If Y = 0, it may be related to the operation of a self-contained CSI feedback in a time slot, which includes CSI report triggering, channel measurement, and up to CSI report.

[0437] For self-contained structures, please refer to the description given above.

[0438] Therefore, the reference resource is defined as being as close as possible to slot n, and the UE measures the channel using CSI-RS during the time period between the CSI report trigger and the CSI report.

[0439] Alternatively, even if Y is a small non-zero value (e.g., Y = 1), since the eNB is designed to trigger CSI reports and receive recent (or new) CSI reports within a short period of time, the reference resource can be defined as close as possible to slot n, and the eNB can perform channel measurements by using a recent CSI-RS close to the CSI report time.

[0440] On the other hand, if Y is a large value, the time of the CSI-RS measurement channel will not cause serious problems compared to the case where Y is small, because a long time has passed from the trigger time to the reporting time.

[0441] Therefore, in this case, proposal 3, which will be described later, is not applied; instead, the time offset of the reference resource is configured using one of the following options.

[0442] First, let's describe option 1.

[0443] When P / SP / AP CSI-RS is used to calculate CSI for A-CSI reporting, the time offset of the CSI reference resource is derived from the Z value for a given CSI delay and parameter set, as described below.

[0444] In other words, n CQI_ref and Same as or greater than or equal to The minimum value of time slot n, so that time slot n CQI_ref Corresponding to the effective downlink time slot.

[0445] The above description can be applied to P / SP CSI reports in the same manner.

[0446] Next, option 2 will be described.

[0447] When P / SP / AP CSI-RS is used to calculate CSI for A-CSI reporting, the time offset of the CSI reference resource is derived from the Z value for a given CSI delay and parameter set, as described below.

[0448] n CQI_ref and equal to or greater than for the minimum value, so that time slot n-n CQI_ref corresponds to a valid downlink time slot.

[0449] The above description can be applied to P / SP CSI reports in the same way.

[0450] In the case of Option 2, the reference resource does not include the symbols before 0, 1, 2, 3,..., Z symbols at the CSI report start time at all.

[0451] According to the current standard, since it is not allowed to perform channel measurements or interference measurements after the reference resource, only Option 2 meets the conditions of Proposal 2.

[0452] Next, the details related to aperiodic CSI report timing and CSI relaxation will be briefly described.

[0453] Candidates for the CSI calculation time Z are defined in Table 7 above.

[0454] Although CSI is only sent on PUSCH, if an A-CSI report is triggered in time slot n, the UE does not have to update the CSI for the A-CSI report for the following cases:

[0455] - For the case where M-L-N < Z for a given CSI complexity and parameter set; and

[0456] - For the case where AP CSI-RS resources are sent in time slot n and M-O-N < Z for a given CSI complexity and parameter set.

[0457] Here, L represents the last symbol of the PDCCH in time slot n, M represents the start symbol of the PUSCH, and N represents the TA value in terms of symbols (e.g., TA = 1.4 symbols).

[0458] And, O represents the later symbol between the last symbol of the AP CSI-RS resource for the channel measurement resource (CMR) and the last symbol of the AP CSI-RS resource for the interference measurement resource (IMR).

[0459] And the PUSCH timing offset for the A-CSI report can be determined as follows.

[0460] When only scheduling PUSCH for a single A-CSI report, the DCI field for the PUSCH timing offset is defined from Y in the report setting.

[0461] And when only scheduling PUSCH for multiple A-CSI reports, the DCI field for the PUSCH timing offset is defined as the maximum value among the various Y values in the report setting.

[0462] For example, when Y = {1, 2, 3, 6} in report setting 1 and Y = {2, 3, 4, 5} in report setting 2, Y can be defined as Y = {2, 3, 4, 6}.

[0463] Other details defined in this standard will be described.

[0464] The terms low-complexity CSI and high-complexity CSI can be replaced with low-latency CSI and high-latency CSI, respectively.

[0465] For CSI calculation capabilities, two CSI latency classes are supported.

[0466] The low-latency CSI class is defined as a WB CSI that includes up to four antenna ports. This low-latency CSI class can be applied only when Type I codebook or PMI is not configured.

[0467] The high-latency CSI class is defined as a superset of all CSIs supported by the UE, and the description given above does not apply to L1 RSRP.

[0468] Furthermore, when CSI is sent via PUSCH, the start and length indicator values ​​(SLIV) and the PUSCH mapping type are determined by pusch-symbolAllocation in the same way as with PUSCH, without the need for CSI.

[0469] When UL-SCH is multiplexed on CSI and PUSCH, the PUSCH slot offset is determined solely by the pusch-symbolAllocation, not the K2 value indicated by aperiodicReportSlotOffset.

[0470] The description given above applies only to the case of CSI and data reuse.

[0471] Here, the number of candidate values ​​for aperiodicReportSlotOffset and K2 are the same.

[0472] Further details regarding the A-CSI report will be described later.

[0473] The conditions under which the UE does not need to update the CSI used for A-CSI reporting will be described again based on the description given above.

[0474] First, the A-CSI report triggering for a single CSI will be considered when describing A-CSI report triggering for multiple CSIs.

[0475] Figure 12Illustrates an example of A-CSI report triggering for a single CSI proposed in this specification.

[0476] More specifically, Figure 12 Illustrates an example of A-CSI report triggering for a single CSI, where periodic CSI-RS and CSI reference resources exist within the time window T.

[0477] In this case, the UE must perform DCI decoding, channel estimation, CSI calculation, and Tx preparation within the time window T.

[0478] Therefore, when T < Z, the UE does not need to update the CSI.

[0479] Figure 13 Illustrates an example of A-CSI report triggering for a single CSI with periodic CSI-RS proposed in this specification.

[0480] (Proposal 1)

[0481] In the case of A-CSI report triggering for a single CSI, when T < Z, the UE does not update the CSI.

[0482] Here, T is the duration between the reception time of the last OFDM symbol triggering the DCI and the transmission time of the first OFDM symbol of the AP CSI report.

[0483] Unlike Figure 12 Even if T > Z, Figure 13 Illustrates the case where P CSI-RS and reference resources arrive late in the time window T.

[0484] In this case, even if T > Z, the UE cannot complete the CSI calculation because it starts channel estimation too late.

[0485] Therefore, to prevent this situation from occurring, the UE must perform channel / interference measurement at the ZP / NZP CSI-RS where at least Z symbols are before the first OFDM symbol of the AP CSI report.

[0486] (Proposal 2)

[0487] The UE does not need to measure the channel or interference through the ZP / NZP CSI-RS received from 0 to Z symbols before the transmission time of the first OFDM symbol of the AP CSI report.

[0488] The time offset of the CSI reference resource must be appropriately derived from Z to match Proposal 2.

[0489] Figure 14 And 15An example of the method proposed in this specification for determining the time offset of a CSI reference resource is illustrated.

[0490] More specifically, Figure 14 and 15 The diagram illustrates the method used to determine Z=5. CSI reports two options for time offset starting from the 10th symbol of slot n.

[0491] Figure 14 The illustration shows when An example of an effective CSI-RS location used for CSI reference resources and channel measurements.

[0492] exist Figure 14 In this case, because the reference resource is time slot n-1, the UE cannot use the potential CSI-RS resources at symbols 1, 2, 3, or 4 of time slot n for channel measurements.

[0493] The UE measures the channel from CSI-RS in one or more time slots before time slot n.

[0494] However, this operation introduces too much delay between channel measurements and CSI reporting.

[0495] As a result, it may not support self-contained A-CSI feedback performed in the same single time slot as CSI triggering, channel measurement, and CSI reporting.

[0496] To solve the above problems, such as Figure 15 As shown, n CQI_ref It can be defined as

[0497] in other words, Figure 15 The illustration shows when Another example of an effective CSI-RS location used for CSI reference resources and channel measurements.

[0498] exist Figure 15 In this context, the reference resource is time slot n, and time slot n includes several symbols other than Z.

[0499] As a result, when CSI-RS is transmitted on the first, second, third, or fourth symbol of time slot n, the UE can measure the channel using the transmitted CSI-RS and calculate the CSI from the new channel measurement.

[0500] (Proposal 3)

[0501] When P / SP / AP CSI-RS is used for CSI calculations in A-CSI reports, the time offset of the CSI reference resource is derived from the Z value of the CSI delay and parameter set, as given below.

[0502] Here, n CQI_ref is the minimum value greater than or equal to such that the time slot n - n CQI_ref corresponds to a valid downlink time slot

[0503] Here, a specific time slot can be regarded as a valid downlink time slot when the following conditions are met:

[0504] - When the specific time slot includes downlink or flexible symbols set on at least one upper layer,

[0505] - When the specific time slot is not located within the measurement gap set for the UE,

[0506] - When the active DL BWP in the time slot is the same as the DL BWP for which CSI reporting is performed, and

[0507] - When at least one CSI-RS transmission occasion for channel measurement and the CSI-RS and / or CSI-IM occasions for interference measurement are located no later than the DRS active time of the CSI reference resource for which CSI reporting is performed,

[0508] The above description can be applied to P / SP CSI reporting in the same way.

[0509] When transmitting AP CSI-RS, similar problems to those Figure 13 described in the reference Figure 16 will occur, which will be described in the reference

[0510] As Figure 13 shown, it can be seen that the AP CSI-RS arrives late in the time window T.

[0511] In this case, even if T > Z, the UE cannot complete CSI calculation because it starts channel estimation too late.

[0512] A simple way to solve this problem is to compare T' and Z instead of T and Z.

[0513] Here, T' represents the time interval between the time of reception of the most recent AP CSI-RS and the transmission time of the first OFDM symbol of the AP CSI report.

[0514] Specifically, if T' < Z, the UE updates the CSI and does not have to report the lowest CQI.

[0515] In cases where a more precise mechanism is required, Z' less than Z is defined, and T' and Z' can be compared instead of T' and Z.

[0516] In other words, Z' indicates the amount of time required for channel measurement, CSI calculation, and TX preparation other than DCI decoding.

[0517] Z indicates the time that includes DCI decoding in addition to channel measurement, CSI calculation, and TX preparation.

[0518] However, since the DCI decoding time does not necessarily have to be considered in T', the actual time required for T' may be less than Z.

[0519] If sufficient time is not provided for T', the UE does not have measurements of the considered channels, and thus the UE may report the lowest CQI in a specific UCI field.

[0520] Figure 16 Illustrated is an example of the A-CSI report trigger for a single CSI with non-periodic CSI-RS proposed in this specification.

[0521] (Proposal 4)

[0522] In the case of the A-CSI report trigger for a single CSI using AP CSI-RS, if T' < Z, the UE does not need to calculate the CSI and reports the lowest CQI.

[0523] Here, T' indicates the duration between the time of the most recent CSI-RS reception and the transmission time of the first OFDM symbol for AP CSI reporting.

[0524] In the case of the A-CSI report trigger for multiple N CSIs, if the UE is equipped with N parallel processors, the UE can use the same mechanism as for a single CSI trigger.

[0525] However, if more than N CSIs are triggered, the UE cannot complete the calculation of all the triggered CSIs.

[0526] In this case, the CSI relaxation method supported by the LTE system can be used again.

[0527] (Proposal 5)

[0528] In other words, in the case of the A-CSI report trigger for multiple CSIs, Proposal 5 re-uses the relaxation method supported by the LTE system.

[0529] Now, the UE capabilities for CSI calculation will be described.

[0530] According to the above Proposals 1 to 3, the amount of time required for CSI processing is determined, which is summarized as shown in Tables 8 and 9.

[0531] In other words, Table 8 provides the Z value for a normal UE, which is a reference value that must be supported by all UEs.

[0532] And Table 9 provides the Z value for an advanced UE; thus, for a given parameter set and CSI latency, UE capabilities are used to report whether the Z value in Table 9 is supported.

[0533] Moreover, for a given parameter set and CSI latency, the Z value in Table 9 must be the same as or less than the Z value in Table 8.

[0534] In addition, the value of Z’i,j needs to be added in terms of Z'.

[0535] The value of Z’i,j represents the required duration between the reception time of the nearest CSI-RS and the transmission time of the first OFDM symbol of the AP CSI report.

[0536] Table 8 shows an example of the CSI calculation time Z for a normal UE.

[0537] [Table 8]

[0538] CSI complexity unit 15kHz SCS 30kHz SCS 60kHz SCS 120kHz SCS Low Latency CSI symbol Z1，1 Z1，2 Z1，3 Z1，4 High-latency CSI symbol Z2，1 Z2，2 Z2，3 Z2，4

[0539] Table 9 shows an example of the CSI calculation time Z for an advanced UE.

[0540] [Table 9]

[0541] CSI complexity unit 15kHz SCS 30kHz SCS 60kHz SCS 120kHz SCS Low Latency CSI symbol Z1，1 Z1，2 Z1，3 Z1，4 High-latency CSI symbol Z2，1 Z2，2 Z2，3 Z2，4

[0542] The above proposals are briefly summarized as follows.

[0543] First, according to Proposal 1, if T < Z for an A-CSI report of a single CSI, the UE does not need to update the CSI.

[0544] Here, T represents the duration between the reception time of the last OFDM symbol that triggers the DCI and the transmission time of the first OFDM symbol of the AP CSI report.

[0545] And, according to Proposal 2, the UE does not need to measure the channel or interference caused by the ZP / NZP CSI-RS received from 0 to Z symbols before the transmission time of the first OFDM symbol of the AP CSI report.

[0546] And according to Proposal 3, when P / SP / AP CSI-RS is used for CSI calculation of an A-CSI report, the time offset of the CSI reference resource is derived from Z for a given CSI latency and parameter set as follows.

[0547] In other words, n CQI_refis greater than or equal to the minimum value such that the time slot n - n CQI_ref corresponds to a valid downlink time slot. This property can be applied in the same way as the P / SP CSI report.

[0548] Also, according to Proposal 4, in the case of triggering an A-CSI report for a single CSI using AP CSI-RS, if T' < Z, the UE does not need to calculate the CSI and reports the lowest Channel Quality Indicator (CQI) to the eNB.

[0549] Here, T' represents the duration between the reception time of the most recent AP CSI-RS and the transmission time of the first OFDM symbol of the AP CSI report.

[0550] And in the case of triggering an A-CSI report for multiple CSIs, Proposal 5 uses the relaxation method supported by the LTE system again.

[0551] Next, another embodiment will be described.

[0552] The time offset of the CSI reference resource is derived from Z' regarding CSI delay and parameter set as follows.

[0553] n CQI_ref is greater than or equal to the minimum value such that the time slot n - n CQI_ref corresponds to a valid downlink time slot.

[0554] Alternatively, n CQI_ref can be interpreted as the minimum value among those that are the same as or greater than such that the time slot n - n corresponds to a valid downlink time slot. This property can also be applied to at least non-periodic CSI reports. CQI_ref This property can also be applied to at least non-periodic CSI reports

[0555] And this property is applied when AP / P / SP CSI-RS is used for CSI calculation.

[0556] When P / SP CSI-RS and / or CSI-IM are used for channel or interference measurement, the UE does not expect the last OFDM symbol to measure the channel and / or interference of the CSI-RS and / or CSI-IM received from 0 to Z' symbols before the transmission time of the first OFDM symbol of the AP CSI report

[0557] The above property is not the only condition, and the CSI-RS must be defined at or before the CSI reference resource. This property also includes the case of AP CSI-RS.

[0558] In the case of AP CSI reporting, when P / SP CSI-RS is used for channel and / or interference measurements, the UE does not expect the most recent CSI-RS to be received to be later than the CSI reference resource before triggering PDCCH.

[0559] In Table 10 below, the (Z, Z') values ​​are reference values ​​that must be supported by all UEs.

[0560] For a typical UE, for a given set of parameters, it has not yet been determined whether the (Z, Z') values ​​of the low-latency CSI and high-latency CSI are the same as each other with respect to Table 10 below.

[0561] If two values ​​are the same for all parameter sets, then low latency and high latency are combined into a normal UE.

[0562] In Table 11 below, the UE is able to report to the eNB whether it supports the (Z, Z') values ​​of Table 11 for a given set of parameters and CSI delay.

[0563] For a given set of parameters and CSI delay, the (Z, Z') values ​​in Table 11 must be equal to or less than the (Z, Z') values ​​in Table 10.

[0564] Table 10 illustrates the CSI calculation time Z for a typical UE.

[0565] [Table 10]

[0566] CSI complexity unit 15kHz SCS 30kHz SCS 60kHz SCS 120kHz SCS Low Latency CSI symbol (Z1, 1, Z'1, 1) (Z1, 2, Z'1, 2) (Z1, 3, Z'1, 3) (Z1, 4, Z'1, 4) High-latency CSI symbol (Z2, 1, Z'2, 1) (Z2, 2, Z'2, 2) (Z2, 3, Z'2, 3) (Z2, 4, Z'2, 4)

[0567] Table 11 illustrates the CSI calculation time Z for advanced UEs.

[0568] [Table 11]

[0569] CSI complexity unit 15kHz SCS 30kHz SCS 60kHz SCS 120kHz SCS Low Latency CSI symbol (Z1, 1, Z'1, 1) (Z1, 2, Z'1, 2) (Z1, 3, Z'1, 3) (Z1, 4, Z'1, 4) High-latency CSI symbol (Z2, 1, Z'2, 1) (Z2, 2, Z'2, 2) (Z2, 3, Z'2, 3) (Z2, 4, Z'2, 4)

[0570] As another example, the mechanism related to CSI reporting will be further described.

[0571] More specifically, the timing of CSI reports and the related UE capabilities will be described.

[0572] In the following sections, specific values ​​of (Z, Z') for the standard UE and the advanced UE will be examined using Tables 12 and 13.

[0573] For the Z' value of a normal UE, it is assumed that the UE performs CSI measurement / calculation and channel multiplexing; as well as CSI encoding and modulation of the Z' symbol.

[0574] A portion of the CSI measurement and calculation depends on the parameter set and requires 6*2(μ-2) symbols; the remainder, along with channel multiplexing / CSI coding / modulation, uses 20 symbols for high latency and 13 symbols for low latency, respectively.

[0575] As a result, Z' for low latency and high latency is 13+6*2^(μ-2) and 20+6*2^(μ-2).

[0576] For the Z value of a normal UE, it is assumed that the CSI-RS is located in the next symbol after the final PDCCH symbol.

[0577] Furthermore, it is assumed that CSI processing can begin after DCI decoding.

[0578] DCI decoding time requires 4 + 10 * 2^(μ-2), which includes parts that depend on parameter sets such as PDCCH CE / demultiplexing / decoding and parts that are independent of parameter sets.

[0579] As a result, Z is determined by the DCI decoding time + CSI processing time (i.e., 4 + 10 * 2(μ-2) + Z').

[0580] In the case of advanced UE, since DCI decoding is performed on 5 symbols, Z' is 7 symbols for low latency and 14 symbols for high latency; and Z is Z'+5.

[0581] Table 12 shows the CSI calculation time (Z, Z') for a typical UE.

[0582] [Table 12]

[0583]

[0584] Table 13 shows the CSI calculation time (Z, Z') for advanced UEs.

[0585] [Table 13]

[0586]

[0587] We will examine the various proposals related to the above description.

[0588] The following proposals may be applied separately from or together with the above proposals.

[0589] (Proposal 1')

[0590] As the minimum required CSI processing time for ordinary UE and advanced UE, the (Z, Z') values ​​in Tables 12 and 13 above are selected respectively.

[0591] Regarding CSI and data multiplexing, one remaining issue is the number of symbols required for the UE to simultaneously perform CSI processing and data encoding.

[0592] When CSI and data are reused, the allocation of data resource elements (REs) depends on the CSI payload; however, the CSI / payload size varies depending on the CRI / RI / amplitude coefficient other than 0 or the amount of CSI omitted.

[0593] As a result, CSI processing and data encoding may not be performed in a fully parallel manner.

[0594] More specifically, in the case of Type I CSI, the CRI / RI of Part 1 determines the payload size of Part 2 CSI such as PMI and CQI.

[0595] In the case of Type II CSI, the number of non-zero amplitude coefficients of RI / Part 1 CSI determines the payload size of Part 2 CSI, such as PMI and CQI.

[0596] Therefore, when CSI and data are multiplexed, instead of (Z, Z'), the UE needs at least (Z+C, Z'+C) symbols to prepare CSI and data simultaneously.

[0597] Here, C is less than or equal to N².

[0598] (Proposal 2')

[0599] When AP CSI and data used for PUSCH are multiplexed, the UE is not expected to receive a scheduling DCI with a symbol offset for MLN. <Z+C.

[0600] Here, L represents the last symbol of the PDCCH that triggered the A-CSI report, L is the start symbol of the PUSCH, N is the TA value in symbols, and C is equal to or less than N².

[0601] (Proposal 3')

[0602] When AP CSI and data for PUSCH are multiplexed and AP CSI-RS is used for channel measurements, it is not expected that the UE will receive a scheduled DCI with a symbol offset so that MON... <Z'+C。

[0603] Here, N represents the TA value in symbols; O represents the latest value among the last symbol of the AP CSI-RS resource for CMR, the last symbol of the aperiodic NZP CSI-RS for IM (if it exists), and the last symbol of the aperiodic CSI-IM (if it exists); and C is equal to or less than N2.

[0604] Furthermore, when AP CSI and data used for PUSCH are reused, although the time position of the CSI reference resource is determined in the same way for the AP CSI-only case, the time position is determined based on Z'+C instead of Z'.

[0605] (Proposal 4')

[0606] When AP CSI and data used for PUSCH are multiplexed, the time offset of the CSI reference resource is derived from Z'+C with respect to a given CSI delay and parameter set.

[0607] The time offset of the CSI reference resource is derived from Z' with respect to a given CSI delay and parameter set.

[0608] n CQI_ref Is greater than or equal to The minimum value of , so that time slot nn CQI_ref Corresponding to the effective downlink time slot.

[0609] When P / SP CSI-RS and / or CSI-IM are used for channel and / or interference measurements, the UE does not expect the last OFDM symbol to be used to measure the channel and / or interference with respect to the CSI-RS and / or CSI-IM received from symbols 0 to Z'+C before the transmission time of the first OFDM symbol reported by AP CSI.

[0610] Another issue is the calculation time for beam reporting, namely CRI and Layer 1 Reference Signal Received Power (L1 RSRP).

[0611] When L1 RSRP is a single-port power measurement and the same computed power is used for CSI reporting and beam reporting, L1 RSRP is preferably considered as low-latency CSI.

[0612] In addition, to reduce computational complexity, the number of CSI-RS resources used for beam reporting can be limited.

[0613] (Proposal 5')

[0614] As in CSI reports, the same (Z, Z') applies to beam reports from low-latency CSI.

[0615] Next, in the case of A-CSI report triggering for multiple N CSIs, if the UE is equipped with X parallel processors and X≥N, the same mechanism as for triggering a single CSI report can be used without relaxation.

[0616] However, if more than X CSIs are triggered, the UE cannot complete the calculation for all triggered CSIs.

[0617] In this case, the relaxation method supported by the LTE system can be used again.

[0618] Specifically, if the UE does not have any unreported CSIs and N > X, then the UE is not necessarily required to calculate NX CSIs.

[0619] (Proposal 6')

[0620] In cases where multiple CSIs trigger A-CSI reports, the relaxation method supported in the LTE system can be used again.

[0621] More specifically, if the UE is equipped with X parallel CSI processors and has N unreported CSIs, and N>X, then the UE is not necessarily required to update the Nx most recent CSIs.

[0622] The same method can be applied to the time position of reference resources used in P / SP CSI reports, as can be used for the time position of reference resources used in AP CSI reports.

[0623] (Proposal 7')

[0624] The reference resource time position for the P / SPCSI report can be determined using the same method as the reference resource time position used for the AP CSI report.

[0625] More details related to CSI relaxation will be described in more detail.

[0626] X represents the maximum number of CSIs that can be updated simultaneously.

[0627] If the CSI processing time intervals of N (>X) CSI reports overlap in the time domain, then the UE does not need to update N N CSI reports.

[0628] The CSI processing time interval is the time interval ranging from the beginning of symbol S to the end of symbol E.

[0629] Here, regarding periodic and semi-persistent CSI reports,

[0630] (1) In the case of Alt 1,

[0631] S is the start symbol for the CQI reference resource slot.

[0632] (2) In the case of Alt 2,

[0633] S is E-Z' (or E-(Z'+1)), and E is the start symbol for the CSI report.

[0634] Because NR sets the location of the channel-measurable CSI-RS at the symbol level (in other words, measuring the CSI-RS at symbols below E-Z' or below E-(Z'+1)), Alt.2 proposes the latest time when CSI processing can begin.

[0635] In other words, the UE can start CSI processing no later than Alt.2 time S.

[0636] (3) In the case of Alt.3,

[0637] S is the position of the last symbol of the CSI report received at the most recent time point before the start symbol - Z' (or the start symbol of the CSI report - (Z'+1)) or CSI-RS (which is used to calculate the corresponding CSI).

[0638] Because the UE starts CSI calculation by using CSI-RS at the above time point, the UE is suitable for S and satisfies E = S + Z'.

[0639] Next, regarding CSI reports and CSI-IM with periodic or semi-persistent CSI-RS,

[0640] (1) In the case of Alt.1,

[0641] If the reference resource is located before a PUCCH with aperiodic CSI triggering, then S becomes the last symbol of the PDCCH with aperiodic CSI triggering, and E = S + Z.

[0642] Otherwise, S = E - Z', and E is the start symbol of the CSI report.

[0643] (2) In the case of Alt.2,

[0644] If the start symbol of the CSI report -Z' (or the start symbol of the CSI report -(Z'+1)) precedes the PDCCH with a non-periodic CSI trigger, then S is the last symbol with a non-periodic CSI trigger (or S is the last symbol of the PDCCH with a non-periodic CSI trigger +1), and E = S + Z.

[0645] In other words, if a measurable CSI-RS is received before the PDCCH, the UE can begin CSI calculation after receiving the PDCCH.

[0646] Since the minimum time required from receiving the PDCCH until the CSI report is completed is Z, the time to finish the CSI calculation becomes S+Z.

[0647] Otherwise, S is E-Z' (or E-(Z'+1)), and E is the start symbol of the CSI report.

[0648] In other words, if a measurable CSI-RS is received after the PDCCH, the UE can begin CSI calculation after receiving the CSI-RS.

[0649] Since the minimum time required from receiving the CSI-RS until the CSI report is completed is Z', the time for the CSI calculation to end becomes S+Z'.

[0650] (3) In the case of Alt.2,

[0651] Assume that the latest CSI-RS received at or before the start symbol -Z' (or the start symbol -(Z'+1)) of the CSI report is the "reference CSI-RS". If the last symbol of the reference CSI-RS precedes a PDCCH with aperiodic CSI triggering, then S becomes the last symbol of the PDCCH with aperiodic CSI triggering (or the last symbol of the PDCCH with aperiodic CSI triggering +1), and E = S + Z.

[0652] In other words, if a measurable CSI-RS is received before the PDCCH, the UE can begin CSI calculation after receiving the PDCCH.

[0653] Since the minimum time required from receiving the PDCCH until the CSI report is completed is Z, the time to finish the CSI calculation becomes S+Z.

[0654] Otherwise, S = E - Z' (or E - (Z' + 1)), and E is the start symbol of the CSI report.

[0655] In other words, if a measurable CSI-RS is received after the PDCCH, the UE can begin CSI calculation after receiving the CSI-RS.

[0656] Since the minimum time required from receiving the PDCCH until the CSI report is completed is Z', the time for the CSI calculation to end becomes S+Z'.

[0657] (4) In the case of Alt.4,

[0658] S stands for E-Z' (or E-(Z'+1)), where E is the start symbol for the CSI report.

[0659] Next, regarding non-periodic CSI reporting and CSI-IM with non-periodic CSI-RS,

[0660] S1 is the last symbol of the PDCCH with aperiodic CSI triggering.

[0661] S2 is a late symbol among the last symbols of the aperiodic CSI-RS of CMR, the last symbol of the aperiodic CSI-RS of IMR, and the last symbol of the aperiodic CSI-IM.

[0662] (1) In the case of Alt.1,

[0663] If S1+Z>S2+Z' (in other words, if the position of the OFDM symbol added by the Z symbol in S1 is after the position of the OFDM symbol added by the Z' symbol in S2), then S=S1 and E=S1+Z.

[0664] Otherwise, S = S2, and E = S2 + Z'.

[0665] The UE terminates CSI processing at a later time between S1+Z and S2+Z'.

[0666] Therefore, E is set to the later of the two, and the start time that is completed slightly later between the two is assumed to be the start of the CSI process.

[0667] (2) In the case of Alt.2,

[0668] Set S = S2.

[0669] If S1+Z>S2+Z (in other words, if the OFDM symbol added in S1 by the Z symbol is located after the OFDM symbol added in S2 by the Z' symbol), then E=S1+Z. Otherwise, E=S2+Z'.

[0670] Here, the end time of CSI processing in Alt.2 is the same as in Alt.1, but the start time is fixed to S2 for channel and / or interference estimation.

[0671] This is because AP CSI-RS is always restricted to being received after PDCCH is received, and in this case, the UE is able to start CSI processing at least when CSI-RS reception is complete.

[0672] (3) In the case of Alt.3,

[0673] S is E-Z' (or E-(Z'+1)), and E is the start symbol for the CSI report.

[0674] When CSI is calculated using P / SP CSI-RS and / or CSI interference measurement (IM), multiple measurable CSI-RS can exist in the time domain.

[0675] The UE can calculate the most recent CSI by measuring the CSI-RS received as recently as possible with respect to the CSI reporting time.

[0676] At this point, the CSI-RS located before the reporting time -Z' must also be measured by taking into account the UE's CSI calculation time.

[0677] However, if the calculation time of a CSI (referred to as "CSI 1") overlaps with the calculation time of other CSIs (referred to as "CSI 2"), and exceeds the number of CSIs that can be calculated simultaneously, the UE cannot calculate the CSI portion.

[0678] To address the aforementioned issue, the calculation time for CSI 1 can be scheduled at an earlier time so that it does not overlap with CSI 2.

[0679] This is possible because CSI 1 is calculated using P / SP CSI-RS and / or CSI-IM, so there are multiple P / SP CSI-RS and / or CSI-IM along the time axis, and thus CSI 1 can be pre-calculated using previously received P / SP CSI-RS and / or CSI-IM.

[0680] However, it should be noted that if CSI 1 is calculated too early, a potential interval is introduced to avoid situations where CSI becomes outdated, and CSI 1 can be pre-calculated using P / SP CSI-RS and / or CSI-IM received within the potential interval.

[0681] The potential interval (i.e., the N value proposed below) can be determined by the eNB and indicated to the UE; or the UE can determine the potential interval and report the determined potential interval to the eNB.

[0682] The potential interval terminates at “Report Time-Z” and begins at “End Time-N”.

[0683] When multiple CSIs are reported via the same PUSCH, channel multiplexing / coding / modulation is performed on the multiple corresponding CSIs simultaneously, and therefore, less processing time is required compared to the case where multiple CSIs are reported via different PUSCHs.

[0684] Therefore, when multiple CSIs are reported via the same PUSCH, one of the CSIs requires CSI processing time T, but the remaining CSIs only require the time required for "T - channel multiplexing / coding / modulation".

[0685] Therefore, when the processing time is relaxed for CSI, the remaining CSI is defined as "T-channel multiplexing / coding / modulation", and as a result, the possibility of processing time overlapping with other CSIs can be reduced.

[0686] Furthermore, when using periodic or semi-persistent CSI-RS to measure the channel and / or interference, multiple measurable CSI-RS can exist along the time axis.

[0687] In this case, the UE calculates the CSI by measuring the CSI-RS that exists Z' (or Z'+1) symbols prior to the first OFDM symbol that the reference CSI report begins.

[0688] Therefore, the latest time for UE measurement to use CSI for CSI calculation becomes "refer to the first OFDM symbol before the start of CSI reporting and the symbol before Z' (or Z'+1) symbols".

[0689] Therefore, it is preferable to set the start time of CSI processing to "the symbol before the first OFDM symbol of the start of CSI reporting, which is Z' (or Z'+1) symbols prior to it".

[0690] Furthermore, the end time of CSI processing is preferably set to the first OFDM symbol that begins the CSI report.

[0691] On the other hand, when using aperiodic CSI-RS to measure the channel and / or interference, a measurable CSI-RS can exist along the time axis.

[0692] Therefore, it is preferable to set the start time of CSI processing to "the last symbol of AP CSI-RS and / or AP CSI-IM".

[0693] In the case of periodic or semi-persistent CSI reporting, the reporting time is predefined.

[0694] Therefore, the UE knows the location of the most recent CSI-RS that exists Z' (or Z'+1) symbols before the first OFDM symbol that started the CSI report.

[0695] Therefore, since the calculation can start from the corresponding CSI-RS, S becomes the last OFDM symbol of the corresponding CSI-RS, and E becomes S+Z'.

[0696] In the case of AP CSI reporting, when using AP CSI-RS, there is a CSI-RS along the time axis for CSI calculation.

[0697] It should be noted that because the CSI-RS for CMR is different from the CSI-RS for IMR, there is one CSI-RS for each use along the time axis.

[0698] Therefore, since the calculation can start from the corresponding CSI-RS, S becomes the last OFDM symbol of the corresponding CSI-RS, and E becomes S+Z'.

[0699] In the case of AP CSI reporting, when using P / SP CSI-RS, the most recent CSIRS for CSI calculation can be received before DCI.

[0700] Therefore, if the last OFDM symbol of the corresponding CSI-RS is set to S, the UE will start calculating the CSI when it is uncertain whether the corresponding CSI can be triggered.

[0701] If the corresponding CSI is not triggered, the UE wastes computing power and may encounter problems that prevent the corresponding computing power from being used for other CSI calculations.

[0702] To address the aforementioned issue, S will be defined such that S = E - Z', and E will be defined as the first symbol in the PUSCH CSI report.

[0703] As mentioned above, there may be various combinations of S and E in different Alts, and the corresponding combinations are also applicable to the methods proposed in this specification.

[0704] For example, S and E can be determined by S of Alt.1 and E of Alt.2.

[0705] Furthermore, in proposals 2 and 3 above, Z' can be replaced by Z'-1.

[0706] Since the UE can still calculate the CSI range from CSI-RS and / or CSI-IM to the start symbol of the CSI report even when the Z' time is given, Z' can be replaced by Z'-1.

[0707] For the same reason, in Proposal 4 above, Z' can be replaced by Z'-1.

[0708] Methods for operating UE and eNB

[0709] In the following text, reference will be made to Figure 17 and 23 This describes the operation of the UE and eNB used to perform the methods proposed in this specification.

[0710] Figure 17 This is a flowchart illustrating an example of the method proposed in this specification for operating a UE to perform a CSI report.

[0711] First, the UE receives downlink control information (DCI) from the eNB that triggers an aperiodic CSI report (S1710).

[0712] Furthermore, the UE determines the CSI reference resources related to non-periodic CSI reporting (S1720).

[0713] The CSI reference resource can be defined as a time slot nn in the time domain. CQI_ref .

[0714] More specifically, n CQI_ref It can be equal to or greater than the minimum value of the floor function (first parameter / second parameter) so that the time slot nn CQI_ref Corresponding to the effective downlink time slot.

[0715] Here, a specific timeslot can be considered a valid downlink timeslot when the following conditions are met:

[0716] -Specific time slots include cases where they are set to at least one upper-layer downlink or flexible symbol.

[0717] - When a specific time slot is not located within the measurement gap configured for the UE.

[0718] - The situation where the active DL BWP in the time slot is the same as the DL BWP that makes a CSI report, and

[0719] - In cases where there is at least one CSI-RS transmission opportunity and a CSI-RS and / or CSI-IM opportunity for interference measurement no later than the DRS activity time of the CSI reference resource for which CSI reporting was made,

[0720] Here, the first parameter can be related to the time used for CSI calculations, and the second parameter can represent the number of symbols within a time slot.

[0721] More specifically, the first parameter can be represented by a specific number of symbols (Z'), and the second parameter can be represented by... To express.

[0722] And the second parameter is 14.

[0723] Furthermore, the first parameter can be determined based on the CSI delay and parameter set.

[0724] CSI delay can be represented by CSI calculated delay.

[0725] Furthermore, the UE reports the CSI to the eNB in ​​time slot n based on the CSI reference resources (S1730).

[0726] In addition, the UE receives aperiodic CSI-RS from the eNB.

[0727] Furthermore, the UE calculates CSI based on aperiodic CSI-RS and CSI reference resources.

[0728] Preferably, the process for calculating CSI is performed before step S1730.

[0729] Here, aperiodic CSI-RS can be received after DCI.

[0730] In addition, the UE can send capability information, including the first parameter, to the eNB before step S1710.

[0731] DCI can be received in time slots other than time slot n.

[0732] Figure 17 The operation of the UE can be explained as follows.

[0733] The UE receives downlink control information (DCI) from the base station (BS) in relation to the aperiodic CSI report that will be performed by the UE in time slot n.

[0734] Furthermore, the UE determines the value n based on the number of symbols Z' related to the time used to calculate CSI. CQI_ref .

[0735] Furthermore, the UE determines the time slot nn in the time domain to be used for aperiodic CSI reporting. CQI_ref CSI reference resources.

[0736] Furthermore, the UE is based on the time slot nn CQI_ref The CSI reference resource sends non-periodic CSI reports to the BS in time slot n.

[0737] n CQI_ref Is greater than or equal to The minimum value so that the time slot nn CQI_ref It meets the effective downlink time slot standard.

[0738] Here, It is the floor function and It is the number of symbols in a time slot.

[0739] An effective downlink time slot standard is based at least on (i) the number of symbols Z′ related to the time used to calculate the CSI and (ii) the DCI processing time.

[0740] It is equivalent to 14 symbols in one time slot.

[0741] Additionally, the UE can receive CSI reference resources (slot nn) from the BS. CQI_ref The non-periodic reference signal (CSI-RS) in the ) is used to determine the CSI based on the non-periodic CSI-RS, and a non-periodic CSI report is generated based on the CSI.

[0742] Furthermore, the UE determines the number of symbols Z′ related to the time used to calculate the CSI based on the CSI complexity and subcarrier spacing.

[0743] The number of symbols Z' does not include DCI processing time.

[0744] Furthermore, the UE determines the value n based on the number of symbols Z′ related to the time used to calculate CSI and further based on the number of symbols in a time slot. CQI_ref .

[0745] In addition, the UE can receive DCI in a time slot other than the time slot n where aperiodic CSI reporting is to be performed.

[0746] Furthermore, based on the value n equal to zero CQI_ref Non-periodic CSI reporting can be performed in the same time slot as receiving DCI.

[0747] Figure 18 This is a flowchart illustrating an example of the method proposed in this specification for operating an eNB that receives CSI reports.

[0748] First, the eNB will send downlink control information (DCI) that triggers an aperiodic CSI report to the UE (S1810).

[0749] Furthermore, the eNB receives aperiodic CSI reports from the UE in time slot n (S1820).

[0750] Here, non-periodic CSI reporting relates to the CSI reference resource, which can be identified as time slot nn in the time domain. CQI_ref .

[0751] At this time, n CQI_ref It can be equal to or greater than the minimum value of the floor function (first parameter / second parameter) so that n CQI_ref Corresponding to the effective downlink time slot.

[0752] Here, the first parameter can be related to the time used for CSI calculations, and the second parameter can represent the number of symbols within a time slot.

[0753] More specifically, the first parameter can be represented by a specific number of symbols (Z'), and the second parameter can be represented by... To express.

[0754] Furthermore, the second parameter is 14.

[0755] Furthermore, the first parameter can be determined based on the CSI delay and parameter set.

[0756] CSI delay can be represented by CSI calculated delay.

[0757] In addition, the eNB can send aperiodic CSI-RS to the UE.

[0758] At this point, aperiodic CSI-RS can be sent to the UE after DCI.

[0759] Furthermore, the eNB can receive capability information, including the first parameter, from the UE before step S1810.

[0760] Here, DCI can be sent from time slots other than time slot n.

[0761] See the description below. Figures 19 to 23 The process of implementing the CSI reporting method proposed in this specification in the UE will be described in more detail.

[0762] First, in a wireless communication system, a UE used to report CSI may include a radio frequency (RF) module for transmitting and receiving radio signals, and a processor operatively connected to the RF module.

[0763] The UE's RF module receives downlink control information (DCI) from the eNB that triggers aperiodic CSI reporting.

[0764] Furthermore, the processor controls the UE to determine the CSI reference resources related to non-periodic CSI reports.

[0765] The CSI reference resource can be defined as a time slot nn in the time domain. CQI_ref .

[0766] n can be determined based on a first parameter related to the time used to calculate CSI. CQI_ref .

[0767] Furthermore, the first parameter can be determined based on the CSI delay and parameter set.

[0768] CSI delay can be represented by CSI calculated delay.

[0769] More specifically, n CQI_ref It can be equal to or greater than the minimum value of the floor function (first parameter / second parameter) so that n CQI_ref Corresponding to the effective downlink time slot.

[0770] The second parameter can represent the number of symbols in a time slot.

[0771] More specifically, the first parameter can be represented by a specific number of symbols (Z'), and the second parameter can be represented by... To express.

[0772] Furthermore, the second parameter is 14.

[0773] Now, refer to Figure 19 To describe the calculation of n by the UE CQI_ref The specific method for setting the value.

[0774] in other words, Figure 19 The diagram illustrates the proposed implementation of n in this specification. CQI_ref An example of a value-based method.

[0775] First, the UE's memory stores a predefined second parameter.

[0776] Furthermore, the UE's processor can calculate n by using the first and second parameter values ​​stored in memory. CQI_ref value.

[0777] The first parameter value is determined based on the CSI delay (or CSI calculation delay) and the parameter set (μ).

[0778] like Figure 19 As shown, with a CSI delay of 1, if the parameter set (μ) is 0, 1, 2, 3, then the first parameter values ​​are 8, 11, 21, 36 respectively, and the corresponding n... CQI_ref The values ​​are 0, 0, 1, and 2.

[0779] Furthermore, in the case of CSI delay 2-1, if the parameter set (μ) is 0, 1, 2, 3, then the values ​​of the first parameter are 16, 30, 42, 85 respectively, and the corresponding n... CQI_ref The values ​​are 1, 2, 3, and 6.

[0780] Furthermore, in the case of CSI delay 2-2, if the parameter set (μ) is 0, 1, 2, 3, then the first parameter values ​​are 37, 69, 140, 140 respectively, and the corresponding nCQI_re values ​​are 2, 4, 10, 10.

[0781] Furthermore, the UE's RF module reports the CSI to the eNB in ​​time slot n based on the CSI reference resource.

[0782] In addition, the UE's RF module receives aperiodic CSI-RS from the eNB.

[0783] Furthermore, the UE's processor calculates CSI based on aperiodic CSI-RS and CSI reference resources.

[0784] Preferably, the UE's processor performs the CSI calculation before the UE's RF module reports the CSI.

[0785] Here, aperiodic CSI-RS can be received after DCI.

[0786] In addition, the UE's RF module can send capability information, including the first parameter, to the eNB before receiving the DCI.

[0787] DCI can be received in time slots other than time slot n.

[0788] See the description below. Figures 19 to 23 The process of implementing the CSI reporting method proposed in this specification in an eNB will be described in more detail.

[0789] First, in a wireless communication system, an eNB used to receive CSI reports may include a radio frequency (RF) module for transmitting and receiving radio signals, and a processor operatively connected to the RF module.

[0790] First, the eNB's RF module sends downlink control information (DCI) to the UE to trigger an aperiodic CSI report.

[0791] Furthermore, the eNB's RF module receives non-periodic CSI reports from the UE in time slot n.

[0792] Here, non-periodic CSI reporting relates to the CSI reference resource, which can be identified as time slot nn in the time domain. CQI_ref .

[0793] At this time, n CQI_ref It can be equal to or greater than the minimum value of the floor function (first parameter / second parameter) so that the time slot nn CQI_ref Corresponding to the effective downlink time slot.

[0794] Here, the first parameter can be related to the time used for CSI calculations, and the second parameter can represent the number of symbols within a time slot.

[0795] More specifically, the first parameter can be represented by a specific number of symbols (Z'), and the second parameter can be represented by... To express.

[0796] Furthermore, the second parameter is 14.

[0797] Furthermore, the first parameter can be determined based on the CSI delay and parameter set.

[0798] CSI delay can be represented by CSI calculated delay.

[0799] In addition, the eNB's RF module can send aperiodic CSI-RS to the UE.

[0800] At this point, aperiodic CSI-RS can be sent to the UE after DCI.

[0801] Furthermore, the eNB's RF module can receive capability information, including the first parameter, from the UE before sending the DCI.

[0802] Here, DCI can be sent in time slots other than time slot n.

[0803] The equipment that can typically be used with this invention

[0804] Figure 20 A block diagram of a wireless communication device to which the methods proposed in this specification can be applied is shown.

[0805] refer to Figure 20 The wireless communication system includes an eNB 2010 and multiple UEs 2020 located within the range of the eNB 2010.

[0806] eNB and UE can be represented by radio devices respectively.

[0807] The eNB includes a processor 2011, a memory 2012, and a radio frequency (RF) unit 2013. Processor 2011 implementation reference. Figure 1 and 19 The described functions, processes, and / or methods. The layers of the wireless interface protocol can be implemented by a processor. A memory connected to the processor stores various information to enable the processor to operate. An RF unit connected to the processor transmits and / or receives radio signals.

[0808] The UE includes a processor 2021, a memory 2022, and an RF unit 2023.

[0809] Processor Implementation Reference Figure 1 and 19 The described functions, processes, and / or methods. The layers of the wireless interface protocol can be implemented by a processor. A memory connected to the processor stores various information to enable the processor to operate. An RF unit connected to the processor transmits and / or receives radio signals.

[0810] The memory 2012, 2022 can be installed inside or outside the processor 2011, 2021, and can be connected to the processor by various known means.

[0811] In addition, the eNB and / or UE can be equipped with a single antenna or multiple antennas.

[0812] The antenna 2014 and 2024 perform the function of transmitting and receiving radio signals.

[0813] Figure 21 A block diagram of a communication device according to an embodiment of the present invention is shown.

[0814] In particular, Figure 21 Provided Figure 20 Further details about the UE.

[0815] refer to Figure 21 The UE may include a processor (or digital signal processor (DSP)) 2110, an RF module (or RF unit) 2135, a power management module 2105, an antenna 2140, a battery 2155, a display 2115, a keypad 2120, a memory 2130, a user identification module (SIM) card 2125 (this element is optional), a speaker 2145, and a microphone 2150. The UE may also include a single antenna or multiple antennas.

[0816] Processor 2110 Implementation Reference Figures 1 to 19 The described functions, processes, and / or methods. The layers of the wireless interface protocol can be implemented by a processor.

[0817] The memory 2130 is connected to the processor and stores information related to the operation of the processor. The memory can be installed inside or outside the processor and can be connected to the processor by various known means.

[0818] For example, a user can input command information such as a phone number by pressing (or touching) a button on the keypad 2120 or by activating voice using the microphone 2150. The processor receives the command information and processes it to perform an appropriate operation, such as dialing a phone number. Operable data can be retrieved from the SIM card 2125 or the memory 2130. Furthermore, the processor can identify the user and, for the user's convenience, can display the command information or operable information on the display 2115.

[0819] The RF unit 2135, connected to the processor, transmits and / or receives RF signals. The processor passes command information to the RF module to initiate communication, such as transmitting radio signals including voice communication data. The RF module consists of a receiver and a transmitter for receiving and transmitting radio signals. Antenna 2140 performs the function of transmitting and receiving radio signals. When receiving a radio signal, the RF module transmits the signal and converts it to baseband so that the processor can process it. The processed signal can be converted into audible or readable information that can be output through speaker 2145.

[0820] Figure 22An example of an RF module of a wireless communication device to which the methods proposed in this specification can be applied is illustrated.

[0821] More specifically, Figure 22 The illustration shows an example of an RF module that can be implemented in a frequency division duplex (FDD) system.

[0822] First, along the transmission path, Figure 20 and 21 The processor shown processes the data to be transmitted and provides an analog output signal to the transmitter 2210.

[0823] Within transmitter 2210, a low-pass filter (LPF) 2211 filters the analog output signal to remove noise caused by the analog-to-digital converter (ADC), a mixer 2212 upconverts the signal from baseband to the RF band, and a variable gain amplifier (VGA) 2213 amplifies the signal; the amplified signal is filtered by filter 2214, further amplified by power amplifier (PA) 2215, routed by duplexer 2250 / antenna switch 2260, and transmitted through antenna 2270.

[0824] In addition, along the receiving path, the antenna receives signals from the outside and provides the received signals, which are routed through the antenna switch 2260 / duplexer 2250 and provided to the receiver 2220.

[0825] Within receiver 2220, the received signal is amplified by low-noise amplifier (LNA) 2223, filtered by bandpass filter 2224, and downconverted from RF band to baseband by mixer 2225.

[0826] The down-converted signal is filtered by a low-pass filter (LPF) 2226 and amplified by a VGA 2227 to obtain an analog input signal, which is then provided to the... Figure 20 and 21 The processor shown in the figure.

[0827] In addition, the local oscillator (LO) 2240 generates and transmits LO signals and provides the generated signals to the upconverter 2212 and the downconverter 2225, respectively.

[0828] In addition, the phase-locked loop (PLL) 2230 receives control information from the processor to generate transmit and receive LO signals at appropriate frequencies and provides control signals to the LO generator 2240.

[0829] also, Figure 22 The circuit shown can be used with Figure 22 The structures are arranged differently.

[0830] Figure 23 Another example of an RF module of a wireless communication device to which the methods proposed in this specification can be applied is illustrated.

[0831] More specifically, Figure 23 The illustration shows an example of an RF module that can be implemented in a time-division duplex (TDD) system.

[0832] The transmitter 2310 and receiver 2320 of the RF module in the TDD system have the same structure as the transmitter and receiver of the RF module in the FDD system.

[0833] The following description will focus only on the structure of the RF module in the TDD system, which exhibits differences from the RF module in the FDD system, and will refer to... Figure 22 Describe their identical structures.

[0834] The signal amplified by the transmitter's power amplifier 2315 is routed through the band selection switch 2350, the bandpass filter (BPF) 2360, and the antenna switch 2370, and transmitted through the antenna 2380.

[0835] In addition, along the receiving path, the antenna receives signals from the outside and provides the received signals. The signals are routed through antenna switch 2370, BPF 2360, and band selection switch 2350, and are provided to receiver 2320.

[0836] The above embodiments are combinations of the constituent elements and features of the present invention in a predetermined form. Unless otherwise expressly stated, each individual element or feature must be considered optional. Each individual element or feature can be implemented independently without combination with other elements or features. Furthermore, embodiments of the present invention can also be constructed by combining a portion of elements and / or features. A portion of the structure or feature of an embodiment may be included in another embodiment or may be replaced by a corresponding structure of a feature of another embodiment. It should be clearly understood that claims not expressly referenced within the scope of the present invention can be combined to form embodiments, or may be included in new claims by modification after the application.

[0837] Embodiments of the present invention can be implemented by various means such as hardware, firmware, software, or combinations thereof. In the case of hardware implementation, an embodiment of the present invention can be implemented by using one or more of ASICs (Application-Specific Integrated Circuits), DSPs (Digital Signal Processors), DSPDs (Digital Signal Processing Devices), PLDs (Programmable Logic Devices), FPGAs (Field-Programmable Gate Arrays), processors, controllers, microcontrollers, and microprocessors.

[0838] When implemented via firmware or software, one embodiment of the present invention may be implemented as a module, process, function, etc., performing the above-described functions or operations. The software code may be stored in memory and activated by the processor. The memory may be located internally or externally to the processor and may exchange data with the processor using various known means.

[0839] It will be apparent to those skilled in the art that the invention may be practiced in other specific forms without departing from its essential characteristics. Therefore, the detailed description above should be considered illustrative rather than restrictive in various respects. The scope of the invention should be determined by a reasonable interpretation of the appended claims, and all modifications falling within the equivalent scope of the invention are within its scope.

[0840] [Industrial Applicability]

[0841] This document discloses a method for reporting CSI in a wireless communication system, using examples based on 3GPP LTE / LTE-A systems and 5G systems (new RAT systems); however, in addition to 3GPP LTE / LTE-A systems and 5G systems, the invention can also be applied to various other types of wireless communication systems.

Claims

1. A method for receiving Channel State Information (CSI) reports from a base station (BS) in a wireless communication system, the method comprising: The BS then sends downlink control information (DCI) to the user equipment (UE) in relation to the non-periodic CSI reports that the UE will receive in time slot n. as well as Based on time slot nn in the time domain CQI_ref The CSI reference resource is received by the BS and the non-periodic CSI report received from the UE in the time slot n. Wherein, the time slot nn CQI_ref The CSI reference resources mentioned above will be used in the non-periodic CSI reports. Where, n CQI_ref Is greater than or equal to The minimum value of makes the time slot nn CQI_ref Meets the effective downlink slot standard, and in, It is the floor function and It is the number of symbols in a time slot.

2. The method according to claim 1, wherein, The effective downlink time slot standard is based at least on DCI processing time.

3. The method according to claim 1, wherein, This is equivalent to 14 symbols in a time slot.

4. The method according to claim 1, further comprising: The BS sends the data to the UE in the CSI reference resource slot nn. CQI_ref The non-periodic reference signal (CSI-RS) in the middle, Wherein, the CSI is determined based on the aperiodic CSI-RS, and The non-periodic CSI report is generated based on the CSI.

5. The method according to claim 1, wherein, n is determined based on the number of symbols Z′ associated with the time used to calculate the CSI. CQI_ref .

6. The method according to claim 5, wherein, The effective downlink time slot standard is based at least on (i) the number of symbols Z′ related to the time used to calculate the CSI, and (ii) the DCI processing time.

7. The method according to claim 5, wherein, The number of symbols Z′ related to the time used to compute the CSI is determined based on the CSI complexity and subcarrier spacing.

8. The method according to claim 7, wherein, The number of symbols Z′ does not include DCI processing time.

9. The method according to claim 5, wherein, The number of symbols Z′ related to the time used to calculate the CSI is used to determine n, and further based on the number of symbols in a time slot. CQI_ref .

10. The method according to claim 1, wherein, Sending the DCI includes: The DCI is transmitted in a time slot other than the time slot n in which the aperiodic CSI report is to be received.

11. The method according to claim 1, wherein, Based on n CQI_ref The value is zero, and the aperiodic CSI report is received in the same time slot as the DCI transmission.

12. A base station (BS) configured to receive channel state information (CSI) reports in a wireless communication system, the BS comprising: A radio frequency (RF) module configured to transmit and receive radio signals; At least one processor; and At least one computer memory, operatively connected to and storing instructions for execution by the at least one processor, performing operations including: Send downlink control information (DCI) to the user equipment (UE) in relation to the non-periodic CSI report that the UE will receive in time slot n; as well as Based on time slot nn in the time domain CQI_ref The CSI reference resource is used to receive the aperiodic CSI report from the UE in the time slot n. Wherein, the time slot nn CQI_ref The CSI reference resources mentioned above will be used in the non-periodic CSI reports. Where, n CQI_ref Is greater than or equal to The minimum value of makes the time slot nn CQI_ref Meets the effective downlink slot standard, and in, It is the floor function and It is the number of symbols in a time slot.

13. The BS according to claim 12, wherein, The effective downlink time slot standard is based at least on DCI processing time.

14. The BS according to claim 12, wherein, This is equivalent to 14 symbols in a time slot.

15. The BS according to claim 12, wherein, The operation further includes: The BS sends the data to the UE in the CSI reference resource slot nn. CQI_ref The non-periodic reference signal (CSI-RS) in the middle, Wherein, the CSI is determined based on the aperiodic CSI-RS, and The non-periodic CSI report is generated based on the CSI.

16. The BS according to claim 12, wherein, n is determined based on the number of symbols Z′ associated with the time used to calculate the CSI. CQI_ref .

17. The BS according to claim 16, wherein, The effective downlink time slot standard is based at least on (i) the number of symbols Z′ related to the time used to calculate the CSI, and (ii) the DCI processing time.

18. The BS according to claim 16, wherein, The number of symbols Z′ related to the time used to compute the CSI is determined based on the CSI complexity and subcarrier spacing.

19. The BS according to claim 18, wherein, The number of symbols Z′ does not include DCI processing time.

20. The BS according to claim 16, wherein, The number of symbols Z′ related to the time used to calculate the CSI is used to determine n, and further based on the number of symbols in a time slot. CQI_ref .

21. The BS according to claim 12, wherein, Sending the DCI includes: The DCI is transmitted in a time slot other than the time slot n in which the aperiodic CSI report is to be received.

22. The BS according to claim 12, wherein, Based on n CQI_ref The value is zero, and the aperiodic CSI report is received in the same time slot as the DCI transmission.

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