BR112019009905B1 - METHOD AND USER EQUIPMENT FOR REPORTING CHANNEL STATUS INFORMATION IN THE WIRELESS COMMUNICATION SYSTEM - Google Patents

Abstract

The present invention provides a method for reporting, via a user equipment (UE), channel state information (CSI) in a wireless communication system, the method comprising: receiving, via the UE and from a base station (BS), downlink control (DCI) information relating to an aperiodic CSI report that is to be performed by the UE at an interval; determining, through the UE, a value based on a number of symbols related to a time for computing the CSI; determining, via the UE, a CSI reference resource as being an interval in a time domain that is to be used for the aperiodic CSI reporting; and transmitting, through the UE and to the BS, the aperiodic CSI report on the interval , based on the fact that the CSI reference resource is the interval . According to the present invention, the CSI can be calculated using the latest A CSI-RS and thus the latest CSI can be reported.

Description

FIELD OF TECHNIQUE

[001] 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.

TECHNICAL BACKGROUND

[002] Mobile communication systems have generally been developed to provide voice services while ensuring user mobility. Such mobile communication systems have gradually expanded their coverage from voice services through data services to high-speed data services. However, as current mobile communication systems suffer from lack of features and users demand even faster speed services, the development of more advanced mobile communication systems is necessary.

[003] The requirements of the next generation mobile communication system may include supporting enormous data traffic, a noticeable increase in the throughput of each user, the accommodation of a significantly increased number of connecting devices, very low end-to-end latency cutting edge, and high energy efficiency. For this purpose, various techniques such as small-cell enhancement, dual connectivity, massive multiple-input, multiple-output (MIMO), full-in-band duplex, non-orthogonal multiple access (NOMA), super-wideband support, and device networking have been researched.

REVELATION Technique Problem

[004] An object of the present invention is to provide a method for determining a CSI reference resource related to the CSI report.

[005] The technical objectives to be achieved by the present invention are not limited to those described above, and other technical objectives not mentioned above can also be clearly understood from the descriptions provided below by those skilled in the art to which the present invention belongs.

Technique Solution

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

[007] More specifically, a method performed by a user equipment (UE) comprises receiving, through the UE and from a base station (BS), downlink control (DCI) information related to an aperiodic CSI report which must be performed by the UE in an interval »; determine, through the UE, a value of nco; ;,5 based on a number of symbols Z' related to a time to compute the CSI; determining, via the UE, a CSI reference resource to be a Ü - nco range; in a time domain that should be used for the aperiodic CSI report; and transmitting, through the UE and to the BS, the aperiodic CSI report in interval n, based on the fact that the CSI reference resource is interval n - ...,.

[008] Furthermore, according to the present invention, o is a minor , so that the interval satisfies valid downlink interval criteria, and where is a floor function and range is a number of symbols in a range.

[009] Furthermore, according to the present invention, valid downlink interval criteria are based on at least (i) the number of symbols 1 related to the time to compute the CSI and (ii) a processing time of DCI.

[010] Furthermore, according to the present invention, ' is equal to 14 symbols in a range.

[011] Furthermore, the method according to the present invention further comprises receiving, from the BS, an aperiodic reference signal (CSI-RS) in the CSI reference resource, the interval ?; - -; determine the CSI based on the aperiodic CSI-RS; and generate the aperiodic CSI report based on the CSI.

[012] Furthermore, the method according to the present invention further comprises determining the number of time-related symbols Z' to compute the CSI based on a CSI complexity and a subcarrier spacing.

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

[014] Furthermore, according to the present invention, determine the value ; based on the number of time-related symbols Z' to compute the CSI comprises: determining the value based on the number of time-related symbols Z' to compute the CSI, and further based on a number of symbols in a range.

[015] Furthermore, according to the present invention, receiving the DCI comprises: receiving the DCI in an interval beyond the interval ;; in which the aperiodic CSI report is to be performed.

[016] Furthermore, according to the present invention, based on the value ; which is equal to zero, the aperiodic CSI report is performed at the same interval as the receipt of DCI.

[017] In addition, a user equipment (UE) configured to report channel state information (CSI) in a wireless communication system, wherein the UE comprises: a radio frequency (RF) module configured to transmit and receive radio signals; at least one processor; and at least one computer memory operably connectable to the at least one processor and storing instructions that, when executed, cause the at least one processor to perform operations comprising: receiving, via the RF module and from a base station (BS), downlink control (DCI) information relating to an aperiodic CSI report that is to be performed by the UE on an interval »; determining, by the UE, a value nco;;.,5 based on a number of symbols Z' related to a time to compute the CSI; determine, by the UE, a CSI reference feature to be an interval ■ j - in a time domain that is to be used for the aperiodic CSI report; and transmitting, through the RF module and to the BS, the aperiodic CSI report on interval n, based on the fact that the CSI reference resource is the interval ?! - ?!CC;;..,f.

Advantageous Effects

[018] The present invention determines a CSI reference resource as close as possible to a CSI report time, thus preventing a resource (a few symbols) from being wasted without being used, and reporting the most recent CSI through computation of CSI based on the most recently received CSI-RS.

[019] The technical effects of the present invention are not limited to the technical effects described above, and other technical effects not mentioned in this document can be understood by those skilled in the art to which the present invention belongs from the description below.

DESCRIPTION OF THE DRAWINGS

[020] The accompanying drawings, which are included herein as a part of the detailed descriptions to help understand the present invention provide embodiments of the present invention and describe technical features of the present invention with detailed descriptions below.

[021] Figure 1 illustrates an example of the general system structure of a NR to which a method proposed by this specification can be applied.

[022] Figure 2 illustrates a relationship between an uplink frame and a downlink frame in a wireless communication system to which a method proposed by the present specification can be applied.

[023] Figure 3 illustrates an example of a resource grid supported by a wireless communication system to which a method proposed by the present specification can be applied.

[024] Figure 4 illustrates an example of a sub-frame structure to which a method proposed by the present specification can be applied.

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

[026] Figure 6 is a flowchart illustrating an example of a procedure related to CSI.

[027] Figure 7 illustrates an example of the timing in which a periodic CSI-RS is received.

[028] Figures 8 and 9 illustrate another example of the timing in which a periodic CSI-RS is received.

[029] Figure 10 illustrates an example of a method to measure the CSI using a CSI-RS AP.

[030] Figure 11 illustrates an example of another method for measuring CSI using a CSI-RS AP.

[031] Figure 12 illustrates an example of an A-CSI report trigger for single CSI proposed by the present specification.

[032] Figure 13 illustrates an example of an A-CSI report trigger for a single CSI that has a periodic CSI-RS proposed by this specification.

[033] Figures 14 and 15 illustrate examples of a method for determining a time offset of a CSI reference resource proposed by the present specification.

[034] Figure 16 illustrates an example of an A-CSI report trigger for a single CSI that has an aperiodic CSI-RS proposed by this specification.

[035] Figure 17 is a flowchart illustrating an example of a method for operating a UE that performs the CSI report proposed by the present specification.

[036] Figure 18 is a flowchart illustrating an example of a method for operating an eNB that receives a CSI report proposed by the present specification.

[037] Figure 19 illustrates an example of a method to implement the value of nCQI_REF proposed by this descriptive report.

[038] Figure 20 illustrates a block diagram of a wireless communication device to which methods proposed by this specification can be applied.

[039] Figure 21 illustrates a block diagram of a communication device according to an embodiment of the present invention.

[040] Figure 22 illustrates an example of an RF module of a wireless communication device to which a method proposed by the present specification can be applied.

[041] Figure 23 illustrates another example of an RF module of a wireless communication device to which a method proposed by the present specification can be applied.

BEST WAYS

[042] In the following, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The detailed descriptions to be disclosed below with reference to the accompanying drawings are intended to describe illustrative embodiments of the present invention, however, they are not intended to represent the only embodiment of the present invention. The detailed descriptions below include specific details to provide a complete understanding of the present invention. However, it should be understood by those skilled in the art that the present invention can be incorporated without specific details being introduced.

[043] In some cases, to avoid omitting the essence of the present invention, well-known structures and devices may be omitted or may be represented in the form of a block diagram in relation to the main functions of each structure and device.

[044] A base station in this document is considered as a terminal node of a network, which performs communication directly with a UE. In this document, particular operations considered to be performed by the base station may be performed by an upper node of the base station depending on situations. In other words, it is evident that in a network consisting of a plurality of network nodes including a base station, various operations performed for communicating with a UE can be performed by the base station or by network nodes other than the base station. The term Base Station (BS) can be replaced by a term such as Fixed Station, Node B, Evolved NodeB (eNB), Base Transceiver System (BTS), Access Point (AP) or General NB (gNB). Furthermore, a terminal can be fixed or mobile; and the term may be replaced by a term such as User Equipment (UE), Mobile Station (MS), User Terminal (UT), Mobile Subscriber Station (MSS), Subscriber Station (SS), Advanced Mobile Station (AMS) ), Wireless Terminal (WT), Machine-Type Communication (MTC) device, Machine-to-Machine (M2M) device, or Device-to-Device (D2D) device.

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

[046] The specific terms used in the following descriptions are introduced to help in understanding the present invention, and the specific terms may be used in different ways as long as they do not depart from the technical scope of the present invention.

[047] The technology described below can be used for various types of wireless access systems based on 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) or Non-Orthogonal Multiple Access (NOMA). CDMA can be implemented by such radio technology as Universal Terrestrial Radio Access (UTRA) or CDMA2000. TDMA can be implemented by such radio technology as Global System for Mobile Communications (GSM), General Packet Radio Service (GPRS) or GSM Evolution Enhanced Data Rates (EDGE). OFDMA can be implemented by such radio technology 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). Long Term Evolution (LTE) 3rd Generation Partnership Project (3GPP) is part of Evolved UMTS (E-UMTS) that uses E-UTRA, employing OFDMA for downlink and SC-FDMA for uplink transmission . LTE-A (Advanced) is an evolved version of the 3GPP LTE system.

[048] The 5G NR defines Enhanced Mobile Broadband (eMBB), Mass Machine Type Communication (mMTC), Ultra Reliable and Low Latency Communications (URLLC) and vehicle for everything (V2X) depending on usage scenarios.

[049] And the 5G NR standard is divided into autonomous (SA) and non-autonomous (NSA) modes according to the coexistence between the NR system and the LTE system.

[050] And 5G NR supports multi-subcarrier spacing and supports CP-OFDM for downlink transmission while CP-OFDM and DFT-s-OFDM (SC-OFDM) for uplink transmission.

[051] Embodiments of the present invention can be supported by standard documents disclosed for at least one of the wireless access systems such as IEEE 802, 3GPP and 3GPP2. In other words, those steps or portions among the embodiments of the present invention not described to clearly illustrate the technical principles of the present invention can be supported by the aforementioned documents. In addition, all terms disclosed in this document may be described by the aforementioned standard documents.

[052] For the purpose of clarity, the descriptions are provided primarily in relation to 3GPP LTE/LTE-A, however, the technical features of the present invention are not limited to the specific system.

Definition of terms

[053] eLTE eNB: An eLTE eNB is an evolution of an eNB that supports a connection to an EPC and an NGC.

[054] gNB: A node to support NR in addition to a connection to an NGC

[055] New RAN: A radio access network that supports NR or E-UTRA or interfaces with an NGC

[056] Network slice: A network slice is a network defined by an operator, in order to provide an optimized solution for a specific market scenario that requires a specific requirement together with an interterminal band.

[057] Network Function: A network function is a logical node in an infrastructure that has a well-defined external interface and a well-defined functional operation.

[058] NG-C: A control plane interface used for NG2 reference point between new RAN and an NGC

[059] NG-U: A user plane interface used for NG3 reference point between new RAN and an NGC

[060] Non-Autonomous NR: A deployment configuration where a gNB requires an LTE eNB as an anchor for a control plane connection to an EPC or requires an eLTE eNB as an anchor for a control plane connection to an EPC. an NGC

[061] Non-Autonomous E-UTRA: A deployment configuration where an eLTE eNB requires a gNB as an anchor for a control plane connection to an NGC.

[062] User plane communication port: One NG-U interface endpoint

[063] Numerology: corresponds to a subcarrier spacing in the frequency domain. A different numerology can be defined by scaling reference subcarrier spacing by an integer N.

[064] NR: Radio Access from NR or New Radio

General System

[065] Figure 1 is a diagram illustrating an example of a general structure of a new radio (NR) system to which a method proposed by the present disclosure can be implemented.

[066] With reference to Figure 1, an NG-RAN is composed of gNBs that provide an NG-RA user plane (new AS/PDCP/RLC/MAC/PHY sublayer) and a control plane protocol terminal (RRC) for a UE (User Equipment).

[067] The gNBs are connected to each other via an Xn interface.

[068] The gNBs are also connected to an NGC through an NG interface.

[069] More specifically, the gNBs are connected to an Access and Mobility Management Function (AMF) through an N2 interface and a User Plane Function (UPF) through an N3 interface. NR Numerology (New RAT) and Frame Structure

[070] In the NR system, multiple numerologies can be supported. Numerologies can be defined by subcarrier spacing and a CP (Cyclic Prefix) overhead. The Spacing between the plurality of subcarriers can be derived by scaling the basic subcarrier spacing to an integer N (or/z). Additionally, although it is assumed that a very low subcarrier spacing is not used at a very high subcarrier frequency, a numerology to be used can be selected independently of a frequency band.

[071] Additionally, in the NR system, a variety of frame structures according to multiple numerologies can be supported.

[072] Hereafter in the present document, a numerology and an Orthogonal Frequency Division Multiplexing (OFDM) frame structure, which can be considered in the NR system, will be described.

[073] A plurality of OFDM numerologies supported in the NR system can be defined as in Table 1.

[074] Regarding a frame structure in the NR system, a size of several fields in the time domain is expressed as a multiple of a time unit of = V(Δ/max 'NÍ). In this case, 4/max =480-10 , and N{ =4096. the DL and UL transmission is configured as a radio frame that has a section of = (Vmax-Wf /100)-^s =10ms. The radio frame is composed of ten subframes, each having a section of =(/VmaxjVf /Iθθθ)-^ =lms. In this case, there can be a UL frameset and a DL frameset.

[075] Figure 2 illustrates the relationship between a UL frame and a DL frame in a wireless communication system to which a method proposed by this disclosure can be implemented.

[076] As illustrated in Figure 2, a User Equipment (UE) UL frame number I needs to be transmitted ^TA =^TA^S before the start of a corresponding DL frame in the UE.

[077] Regarding P numerology, intervals are enumerated in order nμ and lo,increasing from in a subframe, and in ascending order of in a radio frame. A range is made up of continuous QFDM symbols of and is determined depending on a numerology in usage and interval setting. Q start of n intervals in a subframe is temporally aligned with start of QFDM symbols in the same subframe.

[078] Not all UEs are capable of transmitting and receiving at the same time, and this means that not all OFDM symbols in a DL slot or a UL slot are available to be used.

[079] Table 2 shows the number of OFDM symbols per range for a normal CP in μ numerology, and Table 3 shows the number of OFDM symbols per range for an extended CP in μ numerology. NR physical resource

[080] Regarding physical resources in the NR system, an antenna port, a resource grid, a resource element, a resource block, a carrier part, etc. can be considered.

[081] Henceforth in this document, the above physical resources that can be considered in the NR system will be described in more detail.

[082] First, with respect to an antenna port, the antenna port is defined so that one channel, over which a symbol on an antenna port is transmitted, can be checked from another channel over which a symbol on the same antenna port is transmitted. When large-scale properties of a received channel over which a symbol on one antenna port can be conferred from another channel over which a symbol on another antenna port is transmitted, the two antenna ports can be in a relationship of QC/QCL (near colocalized or near colocalized). In this document, large-scale properties can include at least one of delay diffusion, Doppler diffusion, Doppler shift, average gain, and average delay.

[083] Figure 3 illustrates an example of a resource grid supported in a wireless communication system to which a method proposed by the present disclosure can be implemented.

[084] With reference to Figure 3, a resource grid is composed of NRBNsc subcarriers in a frequency domain, each subframe composed of OFDM symbols, however, the present disclosure is not limited in that regard.

[085] In the NR system, a transmitted signal is described by one or more resource grids, composed of subcarriers, and OFDM symbols. In this document, above indicates the maximum transmission bandwidth, and can be changed not only between numerologies, but between UL and DL.

[086] In this case, as illustrated in Figure 3, a resource grid can be configured for the numerology μ and an antenna port p.

[087] Each element of the resource grid for numerology μ and of the antenna port p is denoted as a resource element, and can be uniquely identified by a pair of indices \k,l). In this document is an index in the frequency domain, and indicates a location of a symbol within a subframe. To indicate a feature element in a range, the index pair |k, 1) is used. In this document,

[088] The resource element |k, 1) for numerology μ and the gate of a (p-μ) antenna p corresponds to a complex value . When there is no risk of confusion or when a specific antenna port or numerology is specified, the p and μ indices can be dropped and thus the complex value can become a (p) a

[089] Additionally, a physical resource block is defined as sc continuous subcarriers in the frequency domain. In the frequency domain, the Nμ 1 physical resource blocks can be enumerated from . At this point, a relationship between nPRB physical resource block number and resource elements (k, l) can be given as in Equation 1.

[090] Equation 1

[091]

[092] Additionally, with respect to a carrier part, a UE can be configured to receive or transmit the carrier part with the use of only a subset of a resource grid. At that point, a set of resource blocks that the UE is configured to receive or transmit are enumerated from Nμ 1 from 0 to URB in the frequency region.

Self-contained subframe structure

[093] Figure 4 is a diagram illustrating an example of a subframe structure contained in a wireless communication system to which the present disclosure can be implemented.

[094] To minimize data transmission latency in a TDD system, New 5G RAT considers a sub-contained subframe structure as shown in Figure 4.

[095] In Figure 4, a diagonal line area (symbol index 0) represents a UL control area and a black area (symbol index 13) represents a UL control area. An unshaded area can be used for DL data transmission or for UL data transmission. This structure is characterized in that DL transmission and UL transmission are performed sequentially in one subframe, and therefore, DL data transmission and UL ACK/NACK reception can be performed in one subframe. In conclusion, it is possible to reduce the time to retransmit data upon occurrence of a data transmission error and thus minimize a final data transmission latency.

[096] In this sub-frame structure, a time gap is required for a base station or a UE to switch from a transmit mode to a receive mode or switch from a receive mode to a transmit mode. For this purpose, some OFDM symbols at a point in time switching from DL to UL in the sub-contained subframe structure are configured as a guard period (GP).

analog beamforming

[097] Since a wavelength is short in the Millimeter Wave (mmW) range, a plurality of antenna elements can be installed in the same area size. That is, a wavelength in the 30 GHz frequency band is 1 cm, and therefore 64 (8x8) antenna elements can be installed in two-dimensional array with a lambda of 0.5 (i.e. a wavelength) on a 4 X 4 (4 by 4) cm panel. Therefore, in the mmW range, coverage can be improved or an throughput can be increased by increasing a beamforming gain (BF) with a plurality of antenna elements.

[098] In this case, to enable adjustment of transmit power and phase for each antenna element, if a transceiver unit (TXRU) is included, independent beamforming for each frequency feature is possible. However, it is not economical to install TXRU in each of about 100 antenna elements. Therefore, a method is considered, in which a plurality of antenna elements are mapped to a TXRU and a beam direction is adjusted with an analog phase shifter. Such an analogue BF method is capable of producing only one beam direction over the entire frequency band, and there is a disadvantage that frequency selective BF is not allowed.

[099] A hybrid BF can be considered, which is an intermediate between digital BF and analog BF, and which has a B number of TXRU less than the Q number of antenna elements. In this case, although it varies depending on a connection method of a B-number of TXRU and Q-number of antenna elements, the beam directions that can be transmitted at the same time are constrained to be less than B.

[0100] Hereinafter in the present document, typical examples of a method of connecting TXRU and antenna elements will be described with reference to the drawings.

[0101] Figure 5 is an example of an exemplary transceiver unit in a wireless communication system to which the present disclosure can be implemented.

[0102] A TXRU virtualization model represents a relationship between output signals from the TXRUs and output signals from the antenna elements. Depending on a relationship between antenna elements and the TXRUs, the TXRU virtualization model can be classified as a TXRU virtualization model option-1: subarray partition model, as shown in Figure 5(a), or as a TXRU Virtualization Model Option-2: Full Connection Model.

[0103] With reference to Figure 5(a), in the subarray partition model, the antenna elements are 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 elements are connected to only one TXRU.

[0104] With reference to Figure 5(b), in the full connection model, signals from multiple TXRUs are combined and transmitted to a single antenna element (or array of antenna elements). That is, it shows a method in which a TXRU is connected to all antenna elements. In this case, antenna elements are connected to all TXRUs.

[0105] In Figure 5, q represents a signal vector transmitted from antenna elements that have M number of copolymers in a column. W represents a wideband TXRU virtualization weight vector, and W represents a phase vector to be multiplied by an analog phase shifter. That is, an analog beamforming direction is decided by W. x represents a signal vector of M_TXRU number of TXRUs.

[0106] In this document, the mapping of antenna ports and TXRUs can be performed on a 1-to-1 or 1-to-many basis.

[0107] The TXRU-to-element mapping in Figure 5 is merely an example, and the present disclosure is not limited in that regard and can be equivalently applied even to the mapping of TXRUs and antenna elements that can be implemented in a variety of ways. hardware shapes.

[0108] Channel State Information Feedback (CSI)

[0109] In most cellular systems that include an LTE system, a UE receives a pilot signal (or a reference signal) to estimate a channel from a base station, calculate channel state information (CSI) and report the CSI to the base station.

[0110] The base station transmits a data signal based on the CSI information fed back from the UE.

[0111] The CSI information fed back from the UE in the LTE system includes channel quality information (CQI), a precoding matrix index (PMI) and a ranking indicator (RI).

[0112] CQI feedback consists of wireless channel quality information that is provided to the base station for one purpose (link adaptation purpose) of providing guidance as to which modulation and coding scheme (MCS) to apply when the base station transmits data.

[0113] In case there is a high quality wireless communication between the base station and the UE, the UE can feed back a high CQI value and the base station can transmit data by applying a relatively high modulation order and a low channel encoding rate. In the opposite case, the UE can feed back a low CQI value and the base station can transmit data applying a relatively low modulation order and a high channel coding rate.

[0114] PMI feedback consists of preferred precoding matrix information that is provided to a base station to provide guidance as to which MIMO precoding scheme to apply when the base station has installed multiple antennas.

[0115] A UE estimates a downlink MIMO channel between the base station and the UE from a pilot signal, and recommends, through PMI feedback, which MIMO precoding it wants to be applied by the base station.

[0116] In the LTE system, only linear MIMO precoding capable of expressing PMI configuration in a matrix form is considered.

[0117] The base station and the UE share a codebook composed of a plurality of precoding matrices, and each MIMO precoding matrix in the codebook has a unique index.

[0118] Consequently, by feeding back an index corresponding to the most preferred MIMO precoding matrix in the codebook as PMI, the UE minimizes an amount of feedback information thereof.

[0119] A PMI value is not necessarily composed of an index. For example, in the case where there are eight transmitter antenna ports in the LTE system, a final MIMO precoding matrix of 8tx can be derived only when two indices (first PMI and second PMI) are combined.

[0120] The RI feedback consists of information about the number of preferred transmission layers, the information that is provided to the base station to provide guidance as to the number of preferred transmission layers of the UE when the base station and the UE have installed multiple antennas to thus enable multilayer transmission through spatial multiplexing.

[0121] The RI and the PMI are very closely correlated to each other. This is because the base station is able to know which precoding needs to be applied to which layer depending on the number of transmission layers.

[0122] Regarding the PMI/RM feedback configuration, a PMI codebook can be configured in relation to the single layer transmission, and then the PMI can be defined for each layer and feedback, however, this method has a disadvantage that an amount of PMI/RI feedback information increases remarkably according to an increase in the number of transmission layers.

[0123] Consequently, in the LTE system, a PMI codebook is defined depending on the number of transmission layers. That is, for transmission of R layers, a number N of matrices of Nt x R is defined (in this document, R represents the number of layers, Nt represents the number of transmitter antenna ports and N represents the book size of codes).

[0124] Consequently, in LTE, a size of a PMI codebook is defined regardless of the number of transmission layers. As a result, since PMI/RI is defined in this structure, the number of transmission layers (R) conforms to a rank value of the precoding matrix (matrix of Nt x R) and, for this reason, the term “ranking indicator (RI)” is used.

[0125] Unlike PMI/RI in the LTE system, PMI/RI described in the present disclosure is not restricted to mean an index value of a precoding matrix Nt x R and a rank value of the precoding matrix .

[0126] The PMI described in the present disclosure indicate information in a MIMO precoder preferred among MIMO precoders capable of being applied by a transmitter, and a form of the precoder is not limited to a linear precoder that can be expressed in a matrix form, different in LTE system. Additionally, RI described in the present disclosure means broader than RO in LTE and includes feedback information indicating the number of preferred transmission layers.

[0127] CSI information can be obtained in all system frequency domains or some of the frequency domains. In particular, in a wide-bandwidth system, it can be useful to obtain CSI information about some frequency domain (eg, sub-band) preferred by each UE and then feed back the obtained CSI information.

[0128] In the LTE system, the CSI feedback is performed through a UL channel and, in general, the periodic CSI feedback is performed through a physical uplink control channel (PUCCH) and the feedback Aperiodic CSI is performed over the Physical Uplink Shared Channel (PUSCH) which is an UL data channel.

[0129] Aperiodic CSI feedback means temporarily transmitting a feedback only when a base station needs CSI feedback information, and the base station triggers the CSI feedback through a DL control channel such as a PDCCH/ePDCCH.

[0130] In the LTE system, what information a UE needs to feedback in response to triggering the CSI feedback is defined as a PUSCH CSI report mode, as shown in Figure 8, and a PUSCH CSI report mode in the which UE needs to operate is informed to the UE in advance via an upper layer message. Procedure related to Channel State Information (CSI)

[0131] In the new radio (NR) system, a channel state information reference signal (CSI-RS) is used for time/frequency tracking, CSI computation, reference signal received power computation (RSRP ) of the L1 layer (L1) or mobility

[0132] Throughout the present disclosure, “A and/or B” may be interpreted as the same as “including at least one of A or B”.

[0133] CSI computation is related to CSI acquisition, and L1-RSRP computation is related to beam management (BM).

[0134] The CSI indicate all types of information indicative of the quality of a radio channel (or link) formed between a UE and an antenna port.

[0135] Henceforth in this document, the operation of a UE in relation to the procedure related to CSI will be described.

[0136] Figure 6 is a flowchart that illustrates an example of a procedure related to CSI.

[0137] To accomplish one of the aforementioned purposes of a CSI-RS, a terminal (e.g., a UE) receives configuration information related to the CSI from a base station (e.g., a general node B (gNB)) via of a radio resource control (RRC) signaling (S610).

[0138] The CSI-related configuration information may include at least one of the CSI interference management (IM) resource-related information, CSI management configuration-related information, CSI resource-related configuration information, CSI-related information to the CSI-RS feature or information related to CSI reporting configuration.

[0139] CSIIM resource related information may include CSI-IM resource information, CSI-IM resource set information, etc.

[0140] The CSI-IM feature set is identified by a CSI-IM feature set ID (identifier), and a feature set includes at least one CSI-IM feature.

[0141] Each CSI-IM resource is identified by a CSI-IM resource ID.

[0142] CSI resource configuration related information defines a group that includes at least one of a non-zero power (NZP) CSI-RS resource set, a CSI-IM resource set, or a CSI-IM resource set from CSI-SSB.

[0143] That is, the information related to the CSI feature set includes a CSI-RS feature set list, and the CSI-RS feature set list can include at least one of a CSI-RS feature set list. NZP CSI-RS, a CSI-IM feature set list, or a CSI-SSB feature set list.

[0144] CSI resource configuration related information can be expressed as IE of CSI-REsourceConfig.

[0145] The CSI-RS feature set is identified by a CSI-RS feature set ID, and a feature set includes at least one CSI-RS feature.

[0146] Each CSI-RS resource is identified by a CSI-RS resource ID.

[0147] As shown in Table 4, the parameters (for example, the repetition of parameter related to BM, and the trs-Info, parameter related to tracking, indicative of (or that indicates) a purpose of a CSI-RS can be defined for each NZP CSI-RS feature set.

[0148] Table 4 shows an example of the NZP CSI-RS feature set IE.

[0149] In Table 4, parameter repetition is a parameter indicative of the possibility of repeatedly transmitting the same beam, and indicates whether repetition is set to “ON” or “OFF” for each set of NZP CSI-RS resources .

[0150] The term "transmit beam (Tx)" used in the present disclosure can be interpreted as the same as a spatial domain transmit filter, and the term "receive beam (Rx)" used in the present disclosure can be interpreted as as the same as a spatial domain receive filter.

[0151] For example, when parameter repetition in Table 4 is set to “OFF”, a UE does not assume that an NZP CSI-RS resource (or resources) in a resource set is passed to the same NZP resource filter. DL spatial domain transmission and the same Nrofports on all symbols.

[0152] Additionally, parameter repetition corresponding to a higher layer parameter corresponds to ”CSI-RS-ResourceRep” of L1 parameter.

[0153] Information related to the CSI report configuration includes the reportConfigType parameter indicative of a time domain behavior and the reportQuantity parameter indicative of a CSI-related quantity to be reported.

[0154] The time domain behavior can be periodic, aperiodic or semipersistent.

[0155] Additionally, information related to CSI report configuration can be represented as IE of CSI-ReportConfig, and Table 5 shows an example of IE of CSI-ReportConfig.

[0156] Additionally, the UE measures CSI based on CSI-related configuration information (S620).

[0157] CSI measurement may include (1) receiving a CSI-RS through the UE (S621) and (2) computing the CSI based on the received CSI-RS (S622).

[0158] A sequence for the CSI-RS is generated by Equation 2, and an initialization value of a pseudorandom sequence C(i) is defined by Equation 3. Equation 2

[0159] In Equations 2 and 3, it is an interval number within a radio frame, and a pseudorandom sequence generator is initialized with Cint at the beginning of each OFDM symbol, where n;;f is the interval number inside a radio frame.

[0160] Additionally, l indicates an OFDM symbol number in a range, and nID indicates upper layer parameter scrambling ID.

[0161] Additionally, with respect to CSI-RS, resource element (RE) mapping of CSI-RS resources of the CSI-RS is performed in time and frequency domains by the upper layer parameter CSI-RS-ResourceMapping.

[0162] Table 6 shows an example of a CSI-RS-ResourceMapping IE.

[0163] In Table 6, a density (D) indicates a CSI-RS resource density measured in a RE/port/physical resource block (PRB), and nrofPorts indicates the number of antenna ports.

[0164] Additionally, the UE reports the measured CSI to the base station (S630).

[0165] In the present document, when a quantity of CSI-ReportConfig in Table 6 is set to “none(or No report)”, the UE can omit the report.

[0166] However, even when the quantity is set to “none(or No report)”, the UE can report the measured CSI to the base station.

[0167] The case where the quantity is set to “none” is t when an aperiodic TRS is triggered or when repetition is set.

[0168] In this document, it can be defined so that the reporting by the UE is omitted only when the repetition is set to “ON”.

[0169] Briefly, when replay is set to “ON” and “OFF”, a CSI report can indicate any one of “No report”, “SSB (SSBRI) and L1-RSRP Resource Indicator”, and “ CSI-RS Resource Indicator (CRI) and L1-RSRP”.

[0170] Alternatively, the transmission of a CSI report indicative of “SSBRI and L1-RSRP” or “CRI and L1-RSRP” when the repetition is set to “OFF” can be defined so that, and to transmit a CSI report indicative of “No Report”, “SSBRI and L1-RSRP”, or “CRI and L1-RSRP” when replay is “ON”.

CSI measurement and reporting procedure

[0171] The NR system supports more flexible and dynamic CSI measurement and reporting.

[0172] CSI measurement may include receiving a CSI-RS, and acquiring CSI by computing the received CSI-RS.

[0173] As CSI measurement and reporting time domain behaviors, channel measurement (CM) and aperiodic/semipersistent/periodic interference measurement (IM) are supported.

[0174] To configure CSI-IM, four port NZP CSI-RS RE patterns are used.

[0175] IMR based on NR CSI-IM has a similar design to LTE CSI-IM and is configured independent of CSI-RS ZP resources for PDSCH rate compatibility.

[0176] Additionally, each port in the NZP CSI-RS based IMR emulates an interference layer that has (a desirable channel and) a precoded NZP CSI-RS.

[0177] This is about intra-cell interference measurement of a multi-user case, and primarily targets MU interference.

[0178] On each port of the IMR configured based on NZP CSI-RS, the base station transmits the precoded NZP CSI-RS to the UE.

[0179] The UE assumes a channel/interference layer for each port in a resource pool and measures the interference.

[0180] If there is no PMI or RI feedback for a channel, a plurality of resources are configured in one set and the base station or network designates, via DCI, a subset of NZP CSI-RS resources for measurement of channel/interference.

[0181] Resource definition and resource definition configuration will be described in more detail.

[0182] Resource definition

[0183] Each CSI resource definition “CSI-ResourceConfig” includes the CSI resource set configuration of S>1 (which is provided by upper layer parameter “csi-RS-ResourceSetList”).

[0184] In this document, a CSI resource definition corresponds to CSI-RS-resourcesetlist.

[0185] In this document, S represents the number of configured CSI-RS feature sets.

[0186] In this document, the CSI feature set configuration of S>1 includes each CSI feature set including CSI-RS features (consisting of CSI-IM or CSI-RS or NZP), and a feature SS/PBCH block (SSB) used for L1-RSRP computation.

[0187] Each CSI resource definition is placed in a DL bandwidth chunk (BWP) identified by the upper layer parameter bwp-id.

[0188] Additionally, all CSI resource definitions linked to a CSI report definition have the same DL BWP.

[0189] In a CSI resource definition included in CSI-ResourceConfig IE, a time domain behavior of a CSI-RS resource can be indicated by the upper layer parameter, resourceType, and can be configured to be aperiodic, periodic or semipersistent.

[0190] The S number of CSI-RS resource pools configured for periodic and semi-persistent CSI resource definitions is restricted to “1”.

[0191] A configured periodicity and interval offset for periodic and semi-persistent CSI feature definitions are provided from a related DL BWP numerology as provided by bwp-id.

[0192] When the UE is configured with a plurality of CSI-ResourceConfig including the same NZP CSI-RS resource ID, the same time domain behavior is configured for the CSI-ResourceConfig.

[0193] When the UE is configured with a plurality of CSI-ResourceConfig that have the same resource ID as the CSI-IM, the same time domain behavior is configured for the CSI-ResourceConfig.

[0194] Then, one or more CSI resource definitions for channel measurement (CM) and interference measurement (IM) are configured through upper layer signaling.

[0195] - A CSI-IM feature for measuring interference.

[0196] - An NZP CSI-RS feature for measuring interference.

[0197] - An NZP CSI-RS feature for channel measurement.

[0198] That is, a channel measurement resource (CMR) can be a CSI-RS from NZP for CSI acquisition, and an interference measurement resource (IMR) can be a CSI-RS from NZP for CSI-IM and for IM.

[0199] In this document, CSI-IM (or a CSI-RS from ZP to IM) is primarily used for intercell interference measurement.

[0200] Additionally, an NZP CSI-RS for IM is primarily used for multi-user intra-cell interference measurement.

[0201] The UE can assume that a CSI-RS feature (or features) and a CSI-IM/CSI-RS feature (or features) of NZP for interference measurement configured for a CSI report is ”QCL-TypeD ” for each resource.

Resource definition setup

[0202] As described above, a resource definition can represent a list of resource sets.

[0203] Regarding aperiodic CSI, each trigger state configured using the upper layer parameter “CSI-AperiodicTriggerState” is that each CSI-ReportConfig is associated with one or multiple CSI-ReportConfig linked to a periodic resource definition, semipersistent or aperiodic.

[0204] A report definition can be connected to a maximum of three resource definitions.

[0205] - When a resource definition is configured, a resource definition (provided by upper layer parameter resourcesForChannelMeasurement) is about channel measurement for L1-RSRP computation.

[0206] - When two resource definitions are configured, the first resource definition (provided by upper layer parameter resourcesForChannelMeasurement) is for channel measurement and the second resource definition (provided by csi-IM-ResourcesForInterference or nzp-CSI -RS -ResourcesForInterference) is for CSI-IM or for interference measurement performed on an NZP CSI-RS.

[0207] - When three resource definitions are configured, the first resource definition (provided by resourcesForChannelMeasurement) is for channel measurement, the second resource definition (provided by csi-IM-ResourcesForInterference) is for interference measurement based on CSI-IM, and the third resource definition (provided by nzp-CSI-RS-ResourcesForInterference) is for measuring interference based on NZP's CSI-RS.

[0208] Regarding semi-persistent or periodic CSI, each CSI-ReportConfig is linked to a periodic or semi-persistent resource definition.

[0209] - When a resource definition (provided by resourcesForChannelMeasurement) is configured, the resource definition is regarding channel measurement for L1-RSRP computation.

[0210] - When two resource definitions are configured, the first resource definition (provided by resourcesForChannelMeasurement) is for channel measurement, and the second resource definition (provided by tge upper layer parameter “csi-IM-ResourcesForInterference” ) is used for interference measurement performed in CSI-IM.

[0211] The CSI computation regarding the CSI measurement will be described in more detail.

[0212] If the interference measurement is performed in CSI-IM, each CSI-RS resource for channel measurement is associated with a CSI-RS resource in a corresponding resource set by an order of CSI-RS resources and CSI-IM features.

[0213] The number of CSI-RS features for channel measurement is equal to the number of CSI-IM features.

[0214] Additionally, when interference measurement is performed on an NZP CSI-RS, the UE is not expected to be configured with one or more NZP CSI-RS features in an associated feature set within an NZP feature definition. feature for channel measurement.

[0215] A UE configured with the upper layer parameter, nzp-CSI-RS-ResourcesForInterference, is not expected to be configured with 18 or more NZP CSI-RS ports in an NZP CSI-RS resource pool.

[0216] For the CSI measurement, the UE assumes the following.

[0217] - Each NZP CSI-RS port configured for interference measurement corresponds to an interference transmission layer.

[0218] - Every interference transmission layer of NZP CSI-RS ports for interference measurement considers an energy ratio per resource element (EPRE).

[0219] - a different interference signal in a RE (or REs) of an NZP CSI-RS resource for channel measurement, an NZP CSI-RS resource for interference measurement or a CSI-IM resource for interference measurement.

[0220] A CSI reporting procedure will be described in more detail.

[0221] For CSI reporting, time and frequency resources available to a UE are controlled by a base station.

[0222] The CSI may include at least one of a channel quality indicator (CQI), a pre-coding matrix indicator (PMI), a CSI-RS resource indicator (CRI), a SS/PBCH block (SSBRI), a layer indicator (LI), a classification indicator (RI), or L1-RSRP.

[0223] Regarding CQI, PMI, CRI, SSBRI, LI, RI and L1-RSRP, the UE can be configured with CSI-ReportConfig Report Definition of N>1, CSI-ReportConfig Report Definition ResourceConfig of M>1 and a list of one or two trigger states (provided by aperiodicTriggerStateList and semiPersistentOnPUSCH-TriggerStateList) by an upper layer.

[0224] In aperiodicTriggerStateList, each trigger state includes a channel and a list of associated CSI-ReportConfigs selectively indicative of resource set IDs for interference.

[0225] In semiPersistentOnPUSCH-TriggerStateList, each trigger state includes an associated CSI-ReportConfig.

[0226] Additionally, a time-domain behavior of CSI reporting supports periodic, semi-persistent, and aperiodic CSI reporting.

[0227] Hereinafter in this document, the report of periodic, semipersistent and aperiodic CSI will be described.

[0228] The pre-sorting of periodic CSI is performed on a short PUCCH and a long PUCCH.

[0229] A periodicity and an interval offset of the periodic CSI report can be configured by RRC and refer to the IE of CSI-ReportConfig.

[0230] Then, the CSI SP report is performed on a short PUCCH, a long PUCCH or a PUSCH.

[0231] In case of CSI SP on a short/long PUCCH, a periodicity and an interval offset are configured per RRC, and reporting of CSI to an additional MAC CE is enabled/disabled.

[0232] In the case of CSI SP in a PUSCH, a CSI SP report periodicity is configured by RRC, however, an interval offset of the same is not configured by RRC and the CSI SP report is enabled/disabled by DCI ( format 0_1).

[0233] The first CSI report timing follows a PUSCH time domain allocation value indicated by DCI, and the subsequent CSI report timing follows a periodicity that is configured by RRC.

[0234] For the reporting of CSI SP in a PUSCH, a separate RNTI (C-RNTI of SP-CSI) is used.

[0235] DCI format 0_1 can include a CSI request field and enable/disable a specific configured SP-CSI trigger state.

[0236] Additionally, the CSI SP report is enabled/disabled identically or similarly to a mechanism that has data transmission in an SPS PUSCH.

[0237] Then, the aperiodic CSI report is performed in a PUSCH and triggered by DCI.

[0238] In case of CSI APs that have a CSI-RS AP, a CSI-RS AP timing is configured per RRC.

[0239] In this document, a reporting timing of CSI AP is dynamically controlled by DCI.

[0240] A reporting method (for example, transmission in order of PMI/CQI of RI, WB and PMI/CQI of SB) whereby the CSI are divided and reported into a plurality of report occurrences, where the method is applied for CSI reporting based on PUCCH in LTE, not applied in NR.

[0241] Instead, the NR restricts the specific CSI report setting on a short/long PUCCH, and a CSI omission rule is defined.

[0242] Regarding a CSI AP report timing, the PUSCH slot/symbol location is dynamically indicated by DCI. Additionally, candidate range offsets are configured per RRC.

[0243] Regarding the CSI report, a range offset (Y) is configured for each report definition.

[0244] Regarding UL-SCH, a K2 interval offset is configured separately.

[0245] Two CSI latency classes (low latency class and high latency class) are defined in terms of CSI computation complexity.

[0246] Low latency CSIs are WB CSIs that include up to 4 ports Type I codebook or up to 4 ports PMI non-feedback CSI.

[0247] High latency CSI are different from low latency CSI.

[0248] Regarding a normal UE, (Z, Z') is defined in a unit of OFDM symbols.

[0249] Z represents the minimum CSI processing time after receiving CSI trigger DCI and before performing CSI report.

[0250] Z' represents the minimum CSI processing time after receiving CSI-RS regarding a channel/interference and before performing the CSI report.

[0251] Additionally, the UE reports the number of CSI that can be calculated at the same time.

[0252] A-CSI or CSI AP used in this descriptive report indicates aperiodic CSI which are the CSI reported aperiodically by the UE.

[0253] Furthermore, the CSI report or CSI report used in this descriptive report can be considered as having the same meaning.

[0254] For information of the UE capability for A-CSI computation or calculation time, the UE reports a set of supported Z values and the CSI configuration that can be supported for each Z value to the eNB.

[0255] In this document, Z is defined by the minimum required number of symbols for CSI computation for a given CSI configuration.

[0256] More specifically, Z refers to the minimum amount of time required for calculation related to CSI AP processing, such as decode time, channel measurement, CSI calculation, and TX preparation.

[0257] A CSI configuration includes information that indicates wideband only (WB) CSI or subband (SB) CSI and WB; information regarding the maximum number of CSI-RS ports; and information regarding the type 1 codebook or the type 2 codebook.

[0258] When the UE supports a plurality of numerologies, information regarding CSI can be reported for each numerology.

[0259] When an A-CSI report is triggered in interval n in the PUSCH, the UE abandons the A-CSI report for the following cases:

[0260] - A case in which the time gap between the last symbol of the PDCCH and the initial symbol of the PUSCH in interval n is less than a reported value of Z in relation to a given CSI configuration and

[0261] - A case where a CSI-RS AP resource is transmitted from slot n, and the time gap between the last symbol of a CSI-RS resource and the start symbol of the PUSCH is less than one Z value reported against a given CSI configuration.

[0262] And such symbols between the Z symbols before the start symbol of the PUSCH and the start symbol of the PUSCH are not valid as reference resources (CSI).

[0263] Below, an A-CSI report trigger and a related CSI report are described.

[0264] When the eNB triggers an A-CSI report by transmitting downlink control information (DCI) in interval n, the UE operates as follows.

[0265] A-CSI are transmitted by the UE through the PUSCH allocated as a resource by the DCI.

[0266] The PUSCH transmission timing is indicated by a specific field (which is defined as a Y value) of the DCI.

[0267] More specifically, the PUSCH is transmitted from the (n+Y)th interval (n+Y interval) with reference to the n interval that corresponds to the trigger time of the A-CSI report.

[0268] For example, when a DCI field for the value of Y is defined by 2 bits, the value of Y for 00, 01, 10 and 11 is defined, respectively by RRC signaling and, more specifically, defined within a report definition defined through the RRC flag.

[0269] Report definition can also be expressed by report definition or CSI-ReportConfig.

[0270] An A-CSI report trigger can trigger one or more specific report definitions, and the value of 00, 01, 10 and 11 of the DCI field is defined according to the Y value defined within the definition of triggered report.

[0271] As described above, when the time gap or timing gap between the last symbol of the PDCCH and the start symbol of the PUSCH is less than the value of Z corresponding to the CSI configuration of A-CSI triggered, the UE transmits the A-CSI triggered for the eNB without abandoning or updating the A-CSI.

[0272] Since the amount of time allocated for the actual calculation is less than the minimum amount of time that Z requires for calculating the A-CSI, the UE is unable to calculate the A-CSI.

[0273] As a result, the UE does not abandon or update the triggered CSIs.

[0274] When a Non-Zero Power (NZP) CSI-RS or Zero Power (ZP) CSI-RS used for channel estimation or interference estimation of triggered A-CSIs is an aperiodic CSI-RS, the UE estimates a channel or interference through a trigger measurement from the corresponding RS.

[0275] In other words, it indicates that the UE estimates a channel or interference using the corresponding RS (NZP CSI-RS or ZP CSI-RS) only.

[0276] At this time, if the time gap between the absolute last symbol of a CSI-RS resource and the start symbol of the PUSCH is less than the value of Z corresponding to the CSI configuration of the triggered A-CSI, the same Like the UE operation described above, the UE transmits the corresponding A-CSI to the eNB without abandoning or updating the corresponding A-CSI.

[0277] And when the UE calculates CSI, the UE does so by assuming the reception of data for a frequency and/or time specific resource area, which is called a CSI reference resource.

[0278] The CSI Reference Resource can simply be called a Reference Resource.

[0279] Since the UE starts the CSI calculation from the CSI reference resource time, the UE can calculate CSI only when the amount of time, as long as the Z symbols of the CSI reference resource time are ensured .

[0280] Therefore, the reference resource time needs to be set at least before z symbols (or z+1 symbols) in relation to the CSI report time.

[0281] For this purpose, when the validity of a reference resource is checked, symbols or gaps before at least z symbols (or z+1 symbols) are determined to be valid with respect to the CSI reporting time, but invalid in another way.

[0282] In this document, the resource reference (CSI) is defined in units of intervals.

[0283] In addition, the range whose number is less than or equal to n - ncQi_REF (namely, the range n - nCQI_REF) is determined as the reference resources (CSI) with reference to the range for the CSI report (for example, the range n).

[0284] The above statement, which says that "symbols or gaps before at least z symbols (or z+1 symbols) are determined to be valid with respect to CSI reporting time, but otherwise invalid", may indicate that nCQI_REF is configured by Eq. 4 below.

[0285] In Eq. 4, the floor discards digits after the decimal point and is denoted by a [•] symbol.

[0286] The UE defines the most recent range that satisfies the validity condition for a reference resource from ranges whose number is less than or equal to n - ncQi_REF as a reference resource.

[0287] Similarly, the UE can simply set the range n - nCQI_REF as the reference resource.

[0288] And the time offset of the CSI reference resource can be determined based on proposal 3 to be described later, and detailed descriptions regarding how the time offset of the CSI reference resource is determined will be provided by proposal 3.

[0289] The A-CSI report trigger field included in the DCI can be interpreted as follows.

[0290] When an eNB instructs a UE to perform an A-CSI trigger for a plurality of report definitions simultaneously, and a Y value definition is different for each report definition, a problem occurs as described below, and a UE operation to solve the problem by various methods will be described.

[0291] For example, a report definition 1 is assumed to be defined as Y = {0, 1, 2, 3}, and a report definition 2 is assumed to be defined as Y = {1, 2, 3, 4} .

[0292] In this case, there is an ambiguity in which the value of the DCI field (2 bits) that indicates the value of Y must be interpreted.

[0293] Therefore, to remove ambiguity, it is proposed that the UE operate according to the following methods. (Method 1)

[0294] The UE newly generates Y' as an intersection between two different Ys and interprets the DCI field according to the value of Y'.

[0295] In other words, in the example above, the intersection of two different Ys is {1, 2, 3}, and the UE interprets 00, 01, 10 and 11 from the DCI field as 1, 2, 3 and 3, respectively.

[0296] If the intersection between two different Ys is {1}, the UE interprets 00, 01, 10 and 11 as 1, 1, 1 and 1, respectively.

[0297] If the intersection between two different Ys is {1, 2}, the UE interprets 00, 01, 10 and 11 as 1, 2, 2 and 2.

[0298] In the example above, when the number of elements belonging to the intersection between two different Ys is smaller than the states (for example, 00, 01, 10 and 11) of the DCI field, the remaining states are defined by repeating the last intersection value.

[0299] However, unlike the definition above, the remaining states can be defined as reserved. (Method 2)

[0300] The UE interprets the DCI field according to the value of Y defined in one of a plurality of report definitions.

[0301] For example, among a plurality of report definitions, the UE interprets the DCI field using the value of Y for a report definition that has a low report definition index.

[0302] Similarly, among a plurality of report definitions, the UE interprets the DCI field using the value of Y for a report definition that has a low index for a component carrier (CC).

[0303] The UE prioritizes between the report definition index and the CC index and determines a Y value for a report definition using the CC index.

[0304] If the CC index is equal, the UE can then determine the Y value according to the report definition index.

[0305] Or, as described above, the priority can be reversed (a high priority is set for the report definition index). (Method 3)

[0306] The UE can expect that a plurality of report definitions always have the same Y value.

[0307] In other words, the eNB configures report definitions 1 and 2 to have the same Y value through RRC signaling.

[0308] For example, the eNB can configure report definition 1 using Y = {1, 2, 3, 4} and report definition 2 using Y = {1, 2, 3, 4 }. (Method 4)

[0309] The UE determines the time offset of the aperiodic CSI report using the greater of two different Y values.

[0310] For example, report definition 1 can be defined by Y1 = {0, 1, 2, 3}, and report definition 2 can be defined by Y2 = {1, 2, 3, 4}.

[0311] When the DCI field for Y (for example, 2 bits) is "00', Y1 = 0, and Y2 = 1; and therefore, the value of Y is determined by "1", which is the largest between the two values.

[0312] When the DCI field for Y (for example, 2 bits) is "01', Y1 = 1, and Y2 = 2; and therefore, the value of Y is determined by "2", which is the largest between the two values.

[0313] The Y value can be set in the same way as above when the DCI field value is "10" and "11", and the Y value for the DCI field value of "10" and " 11" is determined as "3" and "4", respectively.

[0314] If three Y values are defined, the largest of the three values can be determined as a time offset by applying the same method described above.

[0315] As described above, the eNB can instruct the UE to perform a CSI AP report trigger through a DCI and determine the time offset of the aperiodic CSI report according to the methods described above (Methods 1 to 4) using the defined Y values for the respective N triggered CSI AP report definitions.

[0316] Additionally, the eNB can indicate the data transmission time through the PUSCH while performing a CSI AP report trigger through the same DCI simultaneously.

[0317] At that time, the data transmission time through the PUSCH is set to a value of "K2", and a plurality of candidate sets are set to the UE through the upper layer signaling in advance.

[0318] One of the candidate sets is determined (or selected) as a final K2 value via the DCI field (which is also called a "timing offset field").

[0319] In addition, the DCI field to select the K2 value and the DCI field to select the Y value are not defined by separate fields, however, they are defined by the same DCI field.

[0320] When a CSI AP report trigger occurs, the UE uses the corresponding DCI field to select the Y value, and when PUSCH data scheduling occurs, the corresponding DCI field is used to select the Y value. K2.

[0321] When PUSCH data scheduling occurs while a CSI AP report trigger is performed simultaneously through the DCIs, an ambiguity arises regarding the possibility of defining each value of the timing offset field as a candidate of the value of Y or a candidate of value K2.

[0322] To resolve the ambiguity, it is possible to extend and directly apply the aforementioned methods (Methods 1 to 4).

[0323] In other words, the proposed methods (Methods 1 to 4) above are related to how to set the value of the timing offset field when a plurality of candidate sets of Y are given, and Methods 1 to 4 can also be applied to the set of candidates of K2 treating the set of candidates of K2 as a set of candidates of Y.

[0324] For example, Method 4 can be extended and applied as described below.

[0325] The UE defines the timing offset field using the largest among different values of Y and K2.

[0326] For example, a report definition 1 is assumed to be defined as Y1 = {0, 1, 2, 3}, and a report definition 2 is assumed to be defined as K2 = {3, 4, 5, 6} .

[0327] If the timing offset DCI field is "00", Y1 = 0, Y2 = 1 and K2 = 3; and therefore the timing offset field is determined by the largest value "3".

[0328] If the DCI field is "01", Y1 = 1, Y2 = 2 and K2 = 4; and therefore the timing offset field is determined by the largest value "4".

[0329] 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 as "5" and " 6", respectively.

[0330] The UE can multiplex PUSCH and CSI data in the interval (n + timing offset) with respect to interval n, which received DCI according to an indicated DCI value, and report (or transmit) the multiplexed data and CSI to the eNB simultaneously.

[0331] Now, other methods to interpret the DCI field related to triggering the A-CSI report in addition to the aforementioned methods (Methods 1 to 4) will be described. (Method 5)

[0332] In another method, the UE constructs a union set by combining candidate sets of different Ys and candidate sets of K2 and sets the value of an n-bit timing offset DCI field to the values that vary from the largest element to the 2nth largest element of the union set.

[0333] The UE multiplexes PUSCH and CSI data at interval (n + timing offset) with respect to interval n, which received DCI according to an indicated DCI value, and reports (or transmits) the multiplexed data and CSI to the eNB simultaneously. (Method 6)

[0334] In yet another method, after building a set from the candidate sets of Ys through Methods 1 to 4, a union set is constructed by combining one of the candidate sets of Y and a set of candidates of K2.

[0335] And the DCI field value of an n-bit timing offset is defined by the values that vary from the largest element to the 2nth largest element of the union set. (Method 7)

[0336] Method 7 builds a set from candidate sets of Ys through Methods 1 to 4 and defines the i-th value of the DCI field of the timing offset using a sum of the i-th element of a among the candidate sets of Y and the i-th element of the candidate sets of K2.

[0337] For example, when the candidate set of Y is {1,2,3,4}, and the candidate set of K2 is {5, 6, 7, 8}, the respective DCI field values of n-bit timing offset for 00, 01, 10 and 11 can be set by 1+5 (6), 2+6 (8), 3+7 (10) and 4+8 (12). (Method 8)

[0338] Method 8 builds a set from the candidate sets of Ys through Methods 1 to 4 and defines the i-th value of the timing offset DCI field as a sum of the i-th element of the candidate set of Ys while ignoring the candidate set of K2.

[0339] Next, a relaxation method for calculating the CSI AP will be described.

[0340] The UE reports a value of Z as defined below to the eNB using one of the capabilities of the UE for calculating the CSI AP.

[0341] Assuming CSI, PUSCH only (no HARQ ACK/NACK) for a given numerology and CSI complexity, Z is defined as the minimum required number of symbols for PDCCH detection/decoding time to receive DCI that triggers a CSI report, channel estimation time and CSI calculation time.

[0342] For low complexity CSI, a value of Z for a given numerology is defined as shown in Table 7 below.

[0343] And for high complexity CSI, a value of Z for a given numerology is defined as shown in Table 7 below.

[0344] As described above, Z is defined as a sum of the amount of time required for DCI decoding (meaning DCI decoding time that retains CSI AP triggering information), the amount of time required for the estimation of channel and the amount of time required for the CSI calculation.

[0345] According to the complexity of CSI triggered in relation to the value of Z, the eNB indicates a value of Y (in other words, according to the possibility that they are low complexity CSI or high complexity CSI).

[0346] If DCIs that hold a CSI AP trigger (namely, CSI AP trigger DCI) are assumed to be transmitted for interval n, the UE reports the CSI corresponding to the eNB in interval (n + timing offset Y).

[0347] If the time allocated to the UE for CSI calculation is insufficient for the ability of the UE to calculate the CSI AP, The UE, instead of updating (or calculating) the CSI, transmits the most recently reported CSI or arbitrary CSI (or predefined, specific CSI, for example, CQI=0, PMI=0, and RI=1) for the eNB.

[0348] Figure 7 illustrates the aforementioned situation. In other words, Figure 7 illustrates the timing at which a periodic CSI-RS is received.

[0349] More specifically, Figure 7 illustrates a situation in which the most recent periodic CSI-RS (P) that was received at or before the reference resource time exists within a time period T.

[0350] In Figure 7, the UE measures the CSI through a periodic CSI-RS (CSI-RS P), and it can be seen that the CSI-RS P and the CSI reference resource exist within time T.

[0351] In this case, within the T, the UE performs everything from DCI decoding, channel estimation, and CSI calculation.

[0352] Therefore, the UE compares T and Z and if T < Z, it does not calculate (or update) CSI, but transmits the most recently reported CSI or arbitrary CSI.

[0353] If T >= Z, the UE calculates CSI based on the periodic CSI-RS and reports the calculated CSI to the eNB.

[0354] Figures 8 and 9 illustrate another example of the timing in which a periodic CSI-RS is received.

[0355] In other words, Figures 8 and 9 illustrate a situation in which the most recent CSI-RS P received at or before the reference resource time exists before period T.

[0356] Or, Figures 8 and 9 illustrate a situation in which a CSI-RS P does not exist within period T, however, the CSI-RS P exists before period T.

[0357] In other words, with reference to Figures 8 and 9, the UE has already performed the channel measurement from a CSI-RS (periodic) before a CSI report trigger occurs.

[0358] Therefore, in this case, the UE performs the DCI decoding and the CSI calculation within the period T.

[0359] The UE compares T and Z- (channel estimation time) and if T < Z- (channel estimation time), it does not calculate (or update) CSI, but transmits the most recently reported CSI or arbitrary CSI for the eNB.

[0360] In this document, the UE can report the channel estimation time to the eNB with the use of separate capacity.

[0361] If T >= Z-(channel estimation time), the UE calculates CSI and reports the calculated CSI to the eNB.

[0362] In the present document, Z-(channel estimation time) can be defined by a third variable, Z', and the UE can report Z and Z' to the eNB, respectively.

[0363] Figure 10 illustrates an example of a method to measure the CSI using a CSI-RS AP.

[0364] First, a CSI-RS AP is defined to always exist within the time period T.

[0365] In this case, within the T, the UE performs everything from DCI decoding, channel estimation, and CSI calculation.

[0366] Therefore, the UE compares T and Z and if T < Z, it does not calculate (or update) CSI, but transmits the most recently reported CSI or arbitrary CSI.

[0367] If T >= Z, the UE calculates CSI and reports the calculated CSI to the eNB.

[0368] Figure 11 illustrates an example of another method for measuring CSI using a CSI-RS AP.

[0369] More specifically, Figure 11 illustrates a situation where a CSI-RS AP is transmitted long after the UE finishes decoding the DCI.

[0370] In this case, the UE needs to perform everything from DCI decoding, channel estimation, and CSI calculation within the time period T.

[0371] However, since a CSI-RS AP is transmitted long after DCI decoding is finished, the UE is unable to perform channel measurement and CSI calculation during the time period T until DCI decoding is completed. is completed and the CSI-RS AP is transmitted.

[0372] Therefore, the UE compares T and Z, and if T < Z, it does not calculate (or update) CSI, but it may transmit the most recently reported CSI or arbitrary CSI to the eNB; however, if T >= Z, the UE is unable to calculate CSI and therefore unable to report CSI to the eNB.

[0373] Therefore, to realize the method as shown in Fig. 11 effectively, the eNB needs to transmit a CSI-RS AP within the DCI decode time after the last trigger DCI OFDM symbol.

[0374] Either the eNB needs to transmit a CSI-RS AP before the Z-(decode time) in the first OFDM symbol from which the CSI APs are reported.

[0375] The UE can report the decode time to the eNB through separate capability.

[0376] In the present document, Z-(decoding time) can be defined as a third variable Z', and the UE can report Z and Z' to the eNB, respectively.

[0377] In other words, T' between the time at which the CSI-RS AP used for channel measurement or interference measurement is last received and the initial time at which CSIs are reported is less than Z', the UE determines that the time to calculate the CSI is not enough and does not calculate the CSI.

[0378] Therefore, the UE does not report the valid CSI, however, it reports a predefined dummy CSI value (for example, RI = 1, PMI = 1 and CQI = 1) to the eNB.

[0379] Or, if T' between the last OFDM symbol in which the CSI-RS AP is transmitted and the first OFDM symbol in which the AP-CSI is reported is less than Z-(decoding time), the UE does not calculate (or update) CSI, however, it transmits the most recently reported CSI or arbitrary CSI to the eNB.

[0380] 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 arbitrary CSI.

[0381] If T' >= Z-(decoding time) and T >= Z, the UE calculates CSI and reports the calculated CSI to the eNB.

[0382] The UE can report the decode time to the eNB through separate capability.

[0383] Unlike the proposals to be described later, if Z' is introduced, the Z in proposals 2 and 3 can be replaced with Z'.

[0384] As described above, the Z indicates the minimum time required for all calculations related to CSI AP processing such as DCI decode time, channel measurement, CSI calculation and TX preparation.

[0385] And Z' indicates the minimum time required for channel measurement, CSI calculation and TX preparation.

[0386] Therefore, it can be realized to define the time provided to the UE, spanning from the last reception time of the CSI-RS used for channel measurement or interference measurement to the initial time when the CSI are transmitted, with reference to the Z' which does not include decoding time.

[0387] Proposals 2 and 3 below can be limited (or restricted) to the case where CSI are reported within a short period of time after triggering A CSI report A.

[0388] For example, proposals 2 and 3 to be described later can be applied only to the case of a small value of Y such as Y = 0 (or Y = 1).

[0389] If Y = 0, it may be related to the operation for self-contained CSI feedback that is operated in a range, including triggering CSI report, channel measurement and even CSI report.

[0390] For the self-contained structure, the descriptions provided above can be referenced.

[0391] For this purpose, a reference feature is defined that is as close as possible to the interval n, and the UE is made to measure a channel using a CSI-RS within a period of time between triggering of the CSI report and the CSI report.

[0392] Or even if the Y is a small non-zero value (eg Y = 1) as the eNB is intended to trigger the CSI report and receive a recent (or new) CSI report within a short period of time, a reference resource can be set to be as close as possible to the interval n, and the eNB can be made to perform the channel measurement using a recent CSI-RS close to the time of CSI report.

[0393] On the other hand, if the Y is a larger value, since it already takes a long time from a trigger time to report time, the time that a CSI-RS measures a channel does not cause a critical problem compared to the case where the Y is small.

[0394] Therefore, in this case, proposal 3 to be described later is not applied, but the time offset of the reference resource is configured by one of the following options.

[0395] First, option 1 is described.

[0396] When a CSI-RS P/SP/AP is used to calculate the CSI for the A-CSI report, the time offset of a CSI reference resource is derived from the value of Z relative to a given latency and CSI numerology as described below.

[0397] In other words, nCQI_ref is equal to of I or is the smallest value greater than or equal to so that the n-ncQi_ref range corresponds to a valid downlink range.

[0398] The above description can be applied to the CSI P/SP report in the same way.

[0399] Next, option 2 will be described.

[0400] When a CSI-RS P/SP/AP is used to calculate the CSI for the A-CSI report, the time offset of a CSI reference resource is derived from the value of Z with respect to a given latency and CSI numerology as described below. nCQI_ref is equal to or is the smallest value greater than or equal to , so that the range n-ncQi_ref matches a valid downlink range.

[0401] The above description can be applied to the CSI P/SP report in the same way.

[0402] In the case of option 2, the reference facility simply does not include symbols before 0, 1,2, 3, ..., Z symbols at the start time of CSI reporting.

[0403] According to the current standard, since the channel measurement or interference measurement cannot be performed after the reference resource, only option 2 already satisfies the condition of proposal 2.

[0404] Next, particulars related to the timing of the aperiodic CSI report and CSI relaxation will be briefly described.

[0405] CSI Z calculation time candidates are defined in Table 7 above.

[0406] Although the CSI are transmitted only on the PUSCH, if the A-CSI report is triggered in interval n, the UE does not need to update the CSI regarding the A-CSI report for the following cases:

[0407] - The case where M-L-N < Z for a given CSI complexity and numerology and

[0408] - The case where a CSI-RS AP resource is transmitted in slot n for a given CSI complexity and numerology, and M-O-N < Z.

[0409] In this document, L represents the last symbol of the PDCCH in interval n, M represents the beginning symbol of the PUSCH, and N represents the value of TA (for example, TA = 1.4 symbol) in symbol units.

[0410] E, O represents a trailing symbol between the last symbol of the CSI-RS AP resource for a channel measurement (CMR) resource and the last symbol of the CSI-RS AP resource for an interference measurement resource ( IMR).

[0411] And the PUSCH timing offset for the A-CSI report can be determined as follows.

[0412] When the PUSCH is scheduled only for a single A-CSI report, the DCI field for the PUSCH timing offset is set from Y in a report definition.

[0413] And, when the PUSCH is scheduled only for a plurality of A-CSI reports, the DCI field for the PUSCH timing offset is set to the maximum value among several Y values in the report definition.

[0414] For example, when Y = {1, 2, 3, 6} in report definition 1, and Y = {2, 3, 4, 5} in report definition 2, Y can be defined as Y = {2, 3, 4, 6}.

[0415] Other features defined in the standard will be described.

[0416] The terms low complexity CSI and high complexity CSI can be replaced by low latency CSI and high latency CSI, respectively.

[0417] Two CSI latency classes are supported for CSI capacity computation.

[0418] Low latency CSI class is defined as WB CSI including a maximum of four antenna ports, which can be applied only when a Type I or PMI codebook is not configured.

[0419] The high latency CSI class is defined as a superset of all CSI supported by the UE, and the descriptions given above are not applied to L1 RSRP.

[0420] And, when CSI are transmitted via PUSCH, a start and length indicator (SLIV) value and PUSCH mapping type are determined by pusch-symbolAllocation in the same way as in PUSCH without CSI.

[0421] The PUSCH interval offset when the CSI are multiplexed with the UL-SCH in the PUSCH is determined only by the value of K2 indicated by pusch-symbolAllocation, instead of aperiodicReportSlotOffset.

[0422] The descriptions given above apply only to the case where the CSI are multiplexed with data.

[0423] In this document, the numbers of candidate values for the aperiodicReportSlotOffset and K2 are equal.

[0424] Particulars related to the A-CSI report will be further described.

[0425] The condition for when the UE does not need to update the CSI for the A-CSI report will be described again based on the descriptions provided above.

[0426] First, an A-CSI report trigger with respect to a plurality of CSI will be described with the A-CSI report trigger with respect to a single CSI under consideration.

[0427] Figure 12 illustrates an example of an A-CSI report trigger for single CSI proposed by the present descriptive report.

[0428] More specifically, Figure 12 illustrates an example of an A-CSI report trigger against a single CSI, where a periodic CSI-RS and a CSI reference feature exist within a time window T.

[0429] In this case, the UE needs to perform DCI decoding, channel estimation, CSI calculation and Tx preparation within the time window T.

[0430] Therefore, when T < Z, the UE does not need to update the CSI.

[0431] Figure 13 illustrates an example of an A-CSI report trigger for a single CSI that has a periodic CSI-RS proposed by this descriptive report. (Proposal 1)

[0432] In case of A-CSI report trigger for a single CSI, the UE does not update the CSI when T < Z.

[0433] In the present document, T is a time duration between the reception time of the last OFDM symbol of triggering DCI and the transmission time of the first OFDM symbol of the CSI AP report.

[0434] Unlike Figure 12, although T > Z, Figure 13 illustrates the case in which the CSI-RS P and the reference resource are later in the time window T.

[0435] In this case, although T > Z, the UE is unable to complete the CSI calculation, since it starts the channel estimation too late.

[0436] Therefore, to prevent such a case from occurring, the UE needs to perform channel/interference measurement on the CSI-RS of ZP/NZP, where at least Z symbols are located before the first OFDM symbol of the CSI AP report . (Proposal 2)

[0437] The UE does not need to measure the channel or interference through the CSI-RS of ZP/NZP received from 0 to Z symbols before the transmission time of the first OFDM symbol of the CSI AP report.

[0438] The time offset of the CSI reference resource needs to be properly derived from Z, so that it is compatible with proposal 2.

[0439] Figures 14 and 15 illustrate examples of a method for determining a time offset of a CSI reference resource proposed by this descriptive report.

[0440] More specifically, Figures 14 and 15 illustrate two options for determining a time offset where Z = 5, and a CSI report is started on the 10th symbol of the n interval.

[0441] Figure 14 illustrates an example of valid CSI-RS locations for the CSI reference feature and the channel measurement when ncQi_ref =

[0442] In Figure 14, since the reference resource is interval n-1, the UE is unable to use a potential CSI-RS resource in 1, 2, 3 or 4 symbols of interval n for channel measurement .

[0443] The UE measures the channel of a CSI-RS at one or a few intervals before interval n.

[0444] However, this operation gives a lot of delay between the channel measurement and the CSI report.

[0445] As a result, self-contained CSI-A feedback, which is performed on the same single interval where CSI triggering, channel measurement, and CSI reporting are conducted, may not be supported.

[0446] To solve the aforementioned problem, as shown in Figure 15, ncQi_ref can be defined as .

[0447] In other words, Figure 15 illustrates another example of valid CSI-RS locations for the CSI Reference Facility and Channel Measurement when

[0448] In Figure 15, the reference feature is range n, and range n includes some symbols in addition to Z.

[0449] As a result, when the CSI-RS is transmitted on the 1st, 2nd, 3rd or 4th symbol of interval n, the UE can measure the channel using the transmitted CSI-RS and calculate the CSI to from the new channel measurement. (Proposal 3)

[0450] When CSI-RS P/SP/AP is used for the CSI calculation for the A-CSI report, the time offset of the CSI reference resource is derived from the value of Z with respect to latency of CSI and numerology, as provided below.

[0451] In this document, nCQI_ref is the smallest value greater than or equal to so that the n-nCQI_ref range corresponds to a valid downlink range.

[0452] In this document, a specific range can be considered as a valid downlink range when the following conditions are met:

[0453] - When the specific range includes a downlink or a set of flexible symbols in at least one upper layer,

[0454] - When the specific range is not located within a measurement gap defined for the UE,

[0455] - When the active DL BWP in an interval is equal to the DL BWP for which the CSI report is conducted, and

[0456] - When at least one CSI-RS transmission occasion for channel and CSI-RS measurement and for interference measurement occasion and/or CSI-IM is located in the active DRS time not later than the reference resource of CSI, in which the CSI report is conducted.

[0457] The above description can be applied to the CSI P/SP report in the same way.

[0458] When a CSI-RS AP is transmitted, a problem similar to that described with reference to Figure 13 may occur, which will be described with reference to Figure 16.

[0459] As shown in Figure 13, it can be seen that the CSI-RS AP is later in the T time window.

[0460] In this case, although T > Z, the UE is unable to complete the CSI calculation, since it starts the channel estimation too late.

[0461] A simple method to solve this problem is to compare T’ and Z instead of T and Z.

[0462] In the present document, T' represents a time gap between the most recent CSI-RS AP reception time and the transmission time of the first OFDM symbol of the CSI AP report.

[0463] In particular, if T' < Z, the UE updates the CSI and does not need to report the lowest CQI.

[0464] In the case that requires a more precise mechanism, Z', which is smaller than Z, is defined, and instead of T' and Z, T' and Z' can be compared.

[0465] In other words, Z' indicates the amount of time required for channel measurement, CSI calculation and TX preparation, except for DCI decoding.

[0466] Z indicates the time that includes DCI decoding plus channel measurement, CSI calculation and TX preparation.

[0467] However, since the DCI decoding time does not necessarily need to be considered in T', the time actually needed for T' may be less than Z.

[0468] If sufficient time is not provided for T', the UE does not take the measurement of a channel into account and therefore the UE may report the lowest CQI in a specific UCI field.

[0469] Figure 16 illustrates an example of an A-CSI report trigger for a single CSI that has an aperiodic CSI-RS proposed by this descriptive report. (Proposal 4)

[0470] In the case of triggering the A-CSI report for a single CSI that uses a CSI-RS AP, if T' < Z, the UE does not need to calculate the CSI and reports the lowest CQI.

[0471] In the present document, T' represents a time duration between the most recent CSI-RS reception time and the transmission time of the first OFDM symbol for the CSI AP report.

[0472] In the case of triggering A-CSI reporting for a plurality of N CSIs, if the UE is equipped with N parallel processors, the UE can use the same mechanism that is used in triggering single CSI.

[0473] However, if more than N CSIs are triggered, the UE is unable to complete the calculation of all triggered CSIs.

[0474] In that case, a CSI relaxation method supported by the LTE system can be used again. (Proposal 5)

[0475] In other words, proposal 5 reuses a relaxation method supported by the LTE system in case of an A-CSI report trigger for a plurality of CSI.

[0476] Now, the UE capability for CSI calculation will be described.

[0477] According to proposals 1 to 3 described above, the amount of time required for CSI processing is determined, which can be summarized as shown in Tables 8 and 9.

[0478] In other words, Table 8 provides Z values for normal UEs, which are reference values that need to be supported by all UEs.

[0479] And Table 9 provides the Z values for advanced UEs; therefore, for a given numerology and CSI latency, the UE capability is employed to report the supportability of Z values from Table 9.

[0480] In addition, for the given numerology and CSI latency, the Z values from Table 9 need to be equal to or less than the Z values from Table 8.

[0481] In addition, the value of Z'i,j needs to be added in relation to Z'.

[0482] The value of Z'i,j represents a length of time required between the most recent CSI-RS reception time and the transmission time of the first OFDM symbol of the CSI AP report.

[0483] Table 8 illustrates an example of the CSI Z calculation time for normal UEs.

[0484] Table 9 illustrates an example of CSI Z calculation time for

[0485] The proposals described above are briefly summarized as follows.

[0486] First, as per proposal 1, if T < Z for an A-CSI report trigger against the single CSI, the UE does not need to update the CSI.

[0487] In the present document, T represents a time duration between the reception time of the last OFDM symbol of triggering DCI and the transmission time of the first OFDM symbol of the CSI AP report.

[0488] And, according to proposal 2, the UE does not need to measure a channel or interference due to a CSI-RS from ZP/NZP received from 0 to Z symbols before the transmission time of the first OFDM symbol of the CSI AP report.

[0489] And, according to proposal 3, when a CSI-RS P/SP/AP is used to drive the CSI calculation for the A-CSI report, the time offset of a CSI reference resource is derived from Z with respect to the given latency and CSI numerology as follows.

[0490] In other words, ncQi_ref is the smallest value greater than or equal to so that the n-nCQI_ref range corresponds to a valid downlink range. This property can be applied in the same way as the CSI P/SP report.

[0491] And, according to proposal 4, in case of an A-CSI report trigger in relation to the single CSI, which uses a CSI-RS AP, if T' < Z, the UE does not need to calculate the CSI and reports the lowest channel quality indicator (CQI) to the eNB.

[0492] In this document, T' represents a time duration between the most recent CSI-RS AP reception time and the transmission time of the first OFDM symbol of the CSI AP report.

[0493] And, proposal 5 reuses a relaxation method supported by the LTE system in the case of an A-CSI report trigger for a plurality of CSI.

[0494] Next, another modality will be described.

[0495] The time offset of a CSI reference resource is derived from Z' with respect to latency and CSI numerology given as follows.

[0496] nCQI_ref is the smallest value greater than or equal to such that the n-nCQI_ref range corresponds to a valid downlink range.

[0497] Or nCQI_ref can be interpreted to be equal to be the smallest value among those values greater than that the range n-nCQI_ref matches a valid downlink range. This property can also be applied at least to the aperiodic CSI report.

[0498] And, this property is applied when a CSI-RS of AP/P/SP is used for the CSI calculation.

[0499] When a CSI-RS P/SP and/or CSI-IM is used for channel or interference measurement, the UE does not wait for the last OFDM symbol to measure a channel and/or interference with respect to the CSI-RS and /or CSI-IM received from 0 to Z' symbols before the transmission time of the first OFDM symbol of the CSI AP report.

[0500] The above property is not the only condition, and the CSI-RS needs to be defined in the CSI reference resource or earlier. This property also includes that of the CSI-RS AP.

[0501] In the case of CSI AP reporting, when the CSI-RS P/SP is used for channel and/or interference measurement, the UE does not expect the latest CSI-RS to be received later than the reference resource of CSI before triggering the PDCCH.

[0502] In Table 10 below, the values of (Z, Z') are reference values that need to be supported by all UEs.

[0503] For normal UEs, it has not yet been determined as to whether the values of (Z, Z') in relation to the low latency CSI and high latency CSI in Table 10 below are equal to each other for the given numerology.

[0504] If the two values are the same for all numerology, the low latency and high latency are combined to normal UEs.

[0505] In Table 11 below, the possibility of supporting values of (Z, Z') from Table 11 in relation to the given numerology and CSI latency is reported to the eNB through the UE capability.

[0506] For the given numerology and CSI latency, the values of (Z, Z') from Table 11 need to be equal to or less than the values of (Z, Z') from Table 10.

[0507] Table 10 illustrates the CSI Z calculation time for normal UEs.

[0508] Table 11 illustrates the CSI Z calculation time for advanced UEs.

[0509] As yet another embodiment, a mechanism related to the CSI report will be further described.

[0510] More specifically, the CSI report timing and related UE capability will be described.

[0511] Next, through Tables 12 and 13, specific values of (Z, Z') for a normal UE and an advanced UE will be examined.

[0512] For the Z' value of a normal UE, it is assumed that the UE performs CSI measurement/calculation and channel multiplexing; and the CSI encoding and modulation for the symbol Z'.

[0513] Part of CSI measurement and calculation depends on numerology and requires 6 * 2(μ-2) symbols; the remaining portions and channel multiplexing/CSI encoding/modulation use 20 symbols respectively for high latency and 13 symbols for low latency.

[0514] As a result, Z' for low latency and high latency is 13 + 6 * 2(μ-2) and 20 + 6 * 2 (μ-2).

[0515] For the Z value of a normal UE, it is assumed that a CSI-RS is located in the next symbol of a final PDCCH symbol.

[0516] Furthermore, it is assumed that CSI processing can start after DCI decoding.

[0517] DCI decoding time requires 4 + 10 * 2 (μ-2) including a portion depending on a numerology such as CE/PDCCH demodulation/decoding and a portion independent of numerology.

[0518] As a result, Z is determined by DCI decoding time + CSI processing time, namely 4 + 10 * 2 (μ-2) + Z'.

[0519] In the case of an advanced UE, since the DCI decoding is conducted by 5 symbols, Z' is 7 symbols and 14 symbols, respectively, for a low latency and a high latency; and Z is Z'+5.

[0520] Table 12 represents the CSI calculation time (Z, Z') for a normal UE.

[0521] Table 13 represents the CSI calculation time (Z, Z') for an advanced UE.

[0522] Various proposals related to the above descriptions will be examined.

[0523] The proposals to be described later can be applied separately from the proposals described above or applied together with the aforementioned proposals. (Proposal 1)

[0524] As the minimum CSI processing time required for normal and advanced UEs, the values of (Z, Z') from Tables 12 and 13 above are selected, respectively.

[0525] Regarding data multiplexing and CSI, a remaining issue is the number of symbols required for a UE to complete CSI processing and data encoding simultaneously.

[0526] When CSI and data are multiplexed, the allocation of a data resource element (RE) depends on a CSI load; however, the payload/CSI size varies depending on the CRI/RI/amplitude coefficient other than 0, or the CSI omission number.

[0527] As a result, CSI processing and data encoding may not be performed in a fully parallel manner.

[0528] More specifically, in the case of CSI type I, CRI/RI of Part 1, determine the payload size of the CSI of Part 2, such as PMI and CQI.

[0529] In the case of CSI type II, the number of non-zero amplitude coefficients of RI/CSI of Part 1, determine the load size of the CSI of Part 2, such as PMI and CQI.

[0530] Therefore, when CSI and data are multiplexed, instead of (Z, Z'), the UE requires at least symbol (Z+C, Z'+C) to prepare CSI and data simultaneously.

[0531] In this document, C is less than or equal to N2. (Proposal 2)

[0532] When CSI AP and data for a PUSCH are multiplexed, the UE is not expected to receive scheduling DCI that has a symbol offset such that M-L-N < Z+C.

[0533] In this document, L represents the last symbol of a PDCCH that triggers an A-CSI report, L is an initial symbol of a PUSCH, N is a value of TA in symbol units, and C is equal to or less than than N2. (Proposal 3)

[0534] When the CSI APs and data for a PUSCH are multiplexed, and a CSI-RS AP is used for channel measurement, the UE is not expected to receive scheduling DCIs that have a symbol offset so that M-O-N < Z'+C.

[0535] In this document, N represents a value of TA in symbol units; The represents a value that is later than the last token of a CSI-RS AP resource for a CMR, the last token of an aperiodic NZP CSI-RS for an IM (if any), and the last token of a CSI- aperiodic MI (if any); and C is equal to or less than N2.

[0536] Furthermore, when CSI AP and data for a PUSCH are multiplexed, although the time position of a CSI reference resource is determined in the same way as for the single case of CSI AP, the time position is determined based on Z'+C instead of Z'. (Proposal 4)

[0537] When the CSI APs and the data for a PUSCH are multiplexed, a time offset of a CSI reference resource is derived from Z'+C with respect to a given CSI latency and a numerology.

[0538] The time offset of a CSI reference resource is derived from Z' with respect to a given CSI latency and a numerology as follows.

[0539] ncQi_ref is the smallest value greater than or equal to _ , so that the range n-nCQI_ref corresponds to a valid downlink range.

[0540] When a CSI-RS P/SP and/or CSI-IM is used for channel measurement and/or interference measurement, the UE does not expect the last OFDM symbol to measure a channel and/or interference with respect to the CSI-RS and/or CSI-IM received from 0 to Z' + C symbols before the transmission time of the first OFDM symbol of a CSI AP report.

[0541] Another problem is the calculation time for a beam report, namely, received CRI power and layer 1 reference signal (L1 RSRP).

[0542] When L1 RSRP is single port power measurement, and the same calculated power is used for CSI report and beam report, it is preferable to consider L1 RSRP as low latency CSI.

[0543] Also, to reduce calculation complexity, the number of CSI-RS features for a beam report can be limited. (Proposal 5)

[0544] The same (Z, Z') is applied for a beam report from the low latency CSI as in the CSI report.

[0545] Then, in the case of an A-CSI report trigger for a plurality of N CSI, if the UE is equipped with X parallel processors, and X>N, the same mechanism as the single CSI report trigger can be used without relaxation.

[0546] However, if more than X CSIs are triggered, the UE is unable to complete the calculation for all triggered CSIs.

[0547] In this case, a relaxation method supported in the LTE system can be reused.

[0548] In particular, if the UE does not have an unreported CSI (or CSIs), and N > X, the UE need not necessarily calculate N-X CSIs (or CSIs). (Proposal 6)

[0549] In the case of triggering an A-CSI report to a plurality of CSI, a relaxation method supported in the LTE system can be reused.

[0550] More specifically, if the UE is equipped with X parallel CSI processors and has N unreported CSI (or CSIs), and N > X, the UE does not necessarily need to update to the latest N-X CSI (or CSIs).

[0551] Regarding the time position of a reference resource for the CSI P/SP report, the same method for the time position of a reference resource for the CSI AP report can be applied. (Proposal 7)

[0552] The reference resource time position for the CSI P/SP report can be determined by the same method as the reference resource time position for the CSI AP report.

[0553] The particularities related to the relaxation of CSI will be described in more detail.

[0554] X represents the capacity for the maximum number of CSIs that can be updated simultaneously.

[0555] If the CSI processing time intervals of N (> X) CSI reports overlap each other in the time domain, the UE does not need to update N-X CSI reports.

[0556] A CSI processing time interval is a time interval that varies from the beginning of an S symbol to the last of an E symbol.

[0557] In this document, regarding the periodic and semi-persistent CSI report,

[0558] (1) In the case of Amendment 1,

[0559] S is a start symbol of a CQI reference resource range.

[0560] (2) In the case of Am. 2,

[0561] S is E-Z' (or E-(Z'+1)), and E is a start symbol of a CSI report.

[0562] Since the NR defines the location of a measurable per channel at the symbol level (in other words, a CSI-RS located in a symbol below E-Z' or in a symbol below E-(Z'+ 1) is measured), Alt. 2 proposes the latest time that CSI processing can start.

[0563] In other words, the UE can start CSI processing in time S of Alt. 2 at most.

[0564] (3) In the case of Am. 3,

[0565] S is the location of the start symbol of a CSI report - Z' (or the start symbol of a CSI report - (Z'+1)) or the last symbol of the CSI-RS (which is used for the calculation of the corresponding CSI) received at the most recent point in time among the points in time before the start symbol.

[0566] Since the UE starts the CSI calculation using the CSI-RS at the aforementioned point in time, the UE is suitable for S and satisfies E = S + Z'.

[0567] Then, regarding a CSI report and a CSI-IM that has a periodic or semi-persistent CSI-RS,

[0568] (1) In the case of Amendment 1,

[0569] If a reference resource is located before a PUCCH with aperiodic CSI triggers, S becomes the last symbol of the PDCCH with aperiodic CSI triggers, and E = S+Z.

[0570] Otherwise, S = E-Z', and E is the start symbol of a CSI report.

[0571] (2) In the case of Am. 2,

[0572] if the start symbol of a CSI report - Z' (or start symbol of a CSI report - (Z'+1)) is located before the PDCCH with triggering of aperiodic CSI, S is the last symbol with triggering of aperiodic CSI (or S is the last symbol of the PDCCH with triggering of aperiodic CSI + 1), and E = S + Z.

[0573] In other words, if a measurable CSI-RS is received before the PDCCH, the UE can start the CSI calculation after receiving the PDCCH.

[0574] Since the minimum time required until a CSI report is completed after receiving the PDCCH is Z, the time in which the CSI calculation is completed becomes S+Z.

[0575] Otherwise, S is E-Z' (or E-(Z'+1)), and E is the start symbol of a CSI report.

[0576] In other words, if a measurable CSI-RS is received after the PDCCH, the UE can start CSI calculation after receiving the CSI-RS.

[0577] Since the minimum time required until the CSI report is completed after receiving the CSI-RS is Z', the time in which the CSI calculation is completed becomes S+Z'.

[0578] (3) In the case of Am. 3,

[0579] The most recent CSI-RS received at or before the CSI report start symbol - Z' (or CSI report start symbol - (Z'+1)) is a "reference CSI-RS ". If the last symbol of a reference CSI-RS is located before the PDCCH with aperiodic CSI triggers, S becomes the last symbol of the PDCCH with aperiodic CSI triggers (or last symbol of the PDCCH with aperiodic CSI triggers + 1), and E = S + Z.

[0580] In other words, if a measurable CSI-RS is received before the PDCCH, the UE can start the CSI calculation after receiving the PDCCH.

[0581] Since the minimum time required until a CSI report is completed after receiving the PDCCH is Z, the time at which the CSI calculation is completed becomes S + Z.

[0582] Otherwise, S = E-Z' (or E-(Z'+1)), and E is the start symbol of a CSI report.

[0583] In other words, if a measurable CSI-RS is received after the PDCCH, the UE can start CSI calculation after receiving the CSI-RS.

[0584] Since the minimum time required until a CSI report is completed after receiving the CSI-RS is Z', the time when the CSI calculation is completed becomes S + Z'.

[0585] (4) In the case of Am. 4,

[0586] S is E-Z' (or E-(Z'+1)), and E is the start symbol of a CSI report.

[0587] Then, regarding an aperiodic CSI report with an aperiodic CSI-RS and a CSI-IM,

[0588] S1 is the last symbol of a PDCCH with aperiodic CSI activation.

[0589] S2 is the last symbol among the last symbol of an aperiodic CSI-RS in relation to a CMR, the last symbol of the aperiodic CSI-RS in relation to the IMR, and the last symbol of the aperiodic CSI-IM.

[0590] (1) In the case of Amendment 1,

[0591] if S1 + Z > S2 + Z' (in other words, if the location of an OFDM symbol added by Z symbols in S1 is located after the location of OFDM symbol added by Z' symbols in S2), S = S1, and E = S1 + Z.

[0592] Otherwise, S = S2, and E = S2 + Z'.

[0593] The UE finishes processing CSI at a later time between S1 + Z and S2 + Z'.

[0594] Therefore, E is set to the later of the two, and the initial time of which the later between the two is assumed to be the start of CSI processing.

[0595] (2) In the case of Am. 2,

[0596] is defined so that S = S2.

[0597] If S1 + Z > S2 + Z (in other words, if the location of an OFDM symbol added by Z symbols in S1 is located after the location of OFDM symbol added by Z' symbols in S2), E = S1 + Z. Otherwise, E = S2 + Z'.

[0598] In this document, the final processing time of CSI in Alt. 2 is the same as in Alt. 1, however, the initial time is fixed for S2, which is used for channel and/or interference estimation.

[0599] This is due to the fact that a CSI-RS AP is always constrained to be received upon receipt of a PDCCH, and in that case the UE can start CSI processing at least when the receipt of the CSI-RS is completed.

[0600] (3) In the case of Am. 3,

[0601] S is E-Z' (or E-(Z'+1)), and E is the start symbol of a CSI report.

[0602] When CSIs are calculated using a CSI-RS P/SP and/or CSI Interference Measurement (IM), a plurality of measurable CSI-RSs may exist in the time domain.

[0603] The UE can calculate CSI by measuring a CSI-RS received as recently as possible against a CSI report time, thus obtaining recent CSI.

[0604] At this time, too, a CSI-RS located before the reporting time - Z' needs to be measurable taking into account the CSI calculation time of the UE.

[0605] However, if the CSI calculation time (which is called "CSI 1') is overlapped with another CSI calculation time (which is called "CSI 2'), and the number of CSIs that can be calculated at the same time is exceeded, the UE is unable to calculate part of the CSIs.

[0606] To solve the above problem, the calculation time of CSI 1 can be set to an earlier time, so that it may not overlap with CSI 2.

[0607] This is possible since CSI 1 is calculated using a CSI-RS P/SP and/or CSI-IM, a plurality of CSI-RSs P/SP and/or CSI-IMs exist throughout the time axis and thus the CSI 1 can be calculated in advance using the previously received CSI-RS P/SP and/or CSI-IM.

[0608] However, it should be noted that if the CSI 1 is calculated too early, a potential gap is introduced to avoid a situation where the CSI is exceeded, and the CSI 1 can be calculated early using the CSI-RS P/SP and/or CSI-IM received within potential range.

[0609] A potential range (namely, the value of N proposed below) can be determined by the eNB and indicated to the UE; or the UE may determine the potential range and report the determined potential range to the eNB.

[0610] The potential interval ends at “report time - Z'” and starts at end time - time N.

[0611] When a plurality of CSIs are reported through the same PUSCH, channel multiplexing/coding/modulation is performed simultaneously to a plurality of corresponding CSIs and therefore a smaller amount of processing time is required compared to the case where that a plurality of CSIs are reported via a different PUSCH.

[0612] Therefore, when a plurality of CSIs are reported through the same PUSCH, one of these CSIs requires the processing time of CSI T, however, the remaining CSI (or CSIs) requires only the time necessary for “T - multiplexing/ channel encoding/modulation”.

[0613] Therefore, when the processing time is set to the CSI relaxation, the remaining CSI are defined as “T-channel multiplexing/coding/modulation”, and as a result, the possibility that the processing time becomes overlap with another CSI can be reduced.

[0614] And, when the channel and/or interference is measured using a periodic or semi-persistent CSI-RS, a plurality of measurable CSI-RSs can exist along the time axis.

[0615] In this case, the UE calculates the CSI by measuring a CSI-RS that exists before the Z' (or Z'+1) symbol with reference to the first OFDM symbol that starts the CSI report.

[0616] Therefore, the last time the UE measures CSI for the CSI calculation becomes “the symbol before Z' (or Z'+1) symbols with reference to the first OFDM symbol that starts the CSI report” .

[0617] Therefore, it is preferable to define the initial CSI processing time as "the symbol before Z' (or Z'+1) symbols with reference to the first OFDM symbol that starts the CSI report".

[0618] And, it is preferable to define the final CSI processing time as the first OFDM symbol that starts the CSI report.

[0619] On the other hand, when the channel and/or interference is measured using an aperiodic CSI-RS, a measurable CSI-RS can exist along the time axis.

[0620] Therefore, it is preferable to define the initial CSI processing time as “the absolute last symbol in which a CSI-RS AP and/or CSI-IM AP is received”.

[0621] In the case of periodic or semi-persistent CSI reports, a report time is defined in advance.

[0622] Therefore, the UE knows the location of a recent CSI-RS that exists before the Z' (or Z'+1) symbol with reference to the first OFDM symbol that starts the CSI report.

[0623] Therefore, since the calculation can be started from the corresponding CSI-RS, S becomes the last OFDM symbol of the corresponding CSI-RS, and E becomes S+Z'.

[0624] In the case of CSI AP reporting, when a CSI-RS AP is used, a CSI-RS used for CSI calculation exists along the time axis.

[0625] It should be noted that, since a CSI-RS for CMR uses is different from a CSI-RS for IMR uses, there is a CSI-RS for each use along the time axis.

[0626] Therefore, since the calculation can be started from the corresponding CSI-RS, S becomes the last OFDM symbol of the corresponding CSI-RS, and E becomes S+Z'.

[0627] In the case of the CSI AP report, when a CSI-RS P/SP is used, the most recent CSI-RS used for the CSI calculation can be received before the DCIs.

[0628] Therefore, if the last OFDM symbol of the corresponding CSI-RS is set to S, the UE starts calculating CSI at a time when it is uncertain whether the corresponding CSI can be triggered or not.

[0629] If the corresponding CSI are not triggered, the UE wastes computing power, and a problem may arise, so that the corresponding computing power is not used for another CSI calculation.

[0630] To solve the above problem, S is defined so that S = E-Z', and E is defined as the first CSI report symbol of PUSCH.

[0631] Various combinations are possible for S and E proposed in the different Alt.s, above, and the corresponding combinations are also applicable to a method proposed by this descriptive report.

[0632] For example, S and E can be determined by the S of Alt. 1 and the E of Alt. 2.

[0633] And, in proposals 2 and 3 above, Z' can be replaced by Z'-1.

[0634] Since the UE may still be able to calculate CSI even if the time of Z' is provided, which varies from a CSI-RS and/or CSI-IM to the start symbol of the CSI report, Z' may be replaced by Z'-1.

[0635] For the same reason, in proposal 4 above, Z' can be replaced by Z'-1. Method for operating a UE and an eNB

[0636] Next, the operations of a UE and an eNB to carry out the method proposed above in this descriptive report will be described with reference to Figures 17 to 23.

[0637] Figure 17 is a flowchart illustrating an example of a method for operating a UE that performs the CSI report proposed by the present specification.

[0638] First, the UE receives downlink control (DCI) information that triggers an aperiodic CSI report from the eNB S1710.

[0639] And the UE determines a CSI reference resource related to the aperiodic CSI report S1720.

[0640] The CSI reference resource can be set to an n-nCQI_ref range in the time domain.

[0641] More specifically, the nCQI_ref can be the smallest value equal to or greater than the floor (a first parameter/a second parameter), so that the n-nCQI_ref range corresponds to a valid downlink range.

[0642] In this document, a specific range can be considered as a valid downlink range when the following conditions are met:

[0643] - The case where the specific range includes a downlink or flexible symbol set for at least one upper layer,

[0644] - The case where the specific range is not located within a measurement gap configured for the UE,

[0645] - The case where an active DL BWP in the interval is equal to a DL BWP in which a CSI report is conducted, and

[0646] - The case where there is at least one CSI-RS and CSI-RS transmission occasion and/or CSI-IM occasion for interference measurement in a DRS active time not subsequent to a CSI reference resource in which a CSI report is conducted.

[0647] In this document, the first parameter can be related to the time for computing the CSI, and the second parameter can represent the number of symbols within an interval.

[0648] More specifically, the first parameter can be represented by a specific number of symbols (Z'), and the second parameter can be represented by intervato

[0649] And the second parameter is 14.

[0650] And the first parameter can be determined based on a CSI latency and a numerology.

[0651] CSI latency can be represented by a CSI computation delay.

[0652] And the UE reports the CSI to the eNB in range n based on the CSI reference resource S1730.

[0653] Additionally, the UE receives an aperiodic CSI-RS from the eNB.

[0654] And the UE computes the CSI based on the aperiodic CSI-RS and the CSI reference resource.

[0655] It is preferable to conduct the process to compute the CSI before step S1730.

[0656] In this document, the aperiodic CSI-RS can be received after the DCI.

[0657] In addition, the UE can transmit capability information including the first parameter to the eNB before step S1710.

[0658] DCI can be received in an interval other than interval n.

[0659] The operation of the UE of Fig. 17 can be interpreted as follows.

[0660] The UE receives, through the UE and from a base station (BS), downlink control (DCI) information related to an aperiodic CSI report that must be carried out by the UE in an interval n.

[0661] And, the UE determines a value based on a number of symbols Z' related to a time to compute the CSI.

[0662] And, the UE determines a CSI reference resource to be an n - nco range; . 5 in a time domain that is to be used for the aperiodic CSI report.

[0663] And, the UE transmits, to the BS, the aperiodic CSI report in interval n, based on the fact that the CSI reference resource is the interval .CQlj'i'f-

[0664] O is a smaller value greater than or equal to that the range ;; - n meets valid downlink interval criteria.

[0665] In this document J is a floor function and V :.:zzà is a number of symbols in a range.

[0666] Valid downlink interval criteria are based on at least (i) the number of symbols z' related to the time to compute the CSI and (ii) a DCI processing time.

[0667] is equal to 14 symbols in a range.

[0668] Additionally, the UE can receive, from the BS, an aperiodic reference signal (CSI-RS) in the CSI reference resource, interval n - ?;co; ;.Í;.-, and determine the CSI based on the aperiodic CSI-RS and generate the aperiodic CSI report based on the CSI.

[0669] And, the UE can determine the number of time-related Z symbols to compute the CSI based on a CSI complexity and a subcarrier spacing.

[0670] The number of Z symbols does not include a DCI processing time.

[0671] And, the UE determines the value nco; .5 based on the number of symbols Z' related to the time to compute the CSI, and additionally based on a number of symbols in an interval.

[0672] Furthermore, the UE may receive the DCI in an interval other than the interval n in which the aperiodic CSI report is to be performed.

[0673] Also, based on the fact that the value nco; be equal to zero, the aperiodic CSI report can be carried out in the same interval as the receipt of DCI.

[0674] Figure 18 is a flowchart illustrating an example of a method for operating an eNB that receives a CSI report proposed by this descriptive report.

[0675] First, the eNB transmits downlink control (DCI) information that triggers an aperiodic CSI report to UE S1810.

[0676] And the eNB receives, from the UE, the aperiodic CSI report in interval n S1820.

[0677] In the present document, the aperiodic CSI report is related to a CSI reference resource, and the CSI reference resource can be determined for an interval n - ncQi_ref in the time domain.

[0678] At this time, the nCQI_ref can be the smallest value equal to or greater than the floor (a first parameter/a second parameter), so that the n-nCQI_ref range corresponds to a valid downlink range.

[0679] In this document, the first parameter can be related to the time for computing the CSI, and the second parameter can represent the number of symbols within an interval.

[0680] More specifically, the first parameter can be represented by a specific number of symbols (Z'), and the second parameter can be represented by . intervato

[0681] And the second parameter is 14.

[0682] And the first parameter can be determined based on a CSI latency and a numerology.

[0683] CSI latency can be represented by a CSI computation delay.

[0684] Additionally, the eNB can transmit an aperiodic CSI-RS to the UE.

[0685] At that time, the aperiodic CSI-RS can be transmitted to the UE after the DCI.

[0686] And the eNB can receive, from the UE, capability information including the first parameter before the step of S1810.

[0687] In this document, the DCI can be transmitted from a range other than range n.

[0688] With reference to Figures 19 to 23 to be described later, a process by which a method for reporting CSI proposed in the present specification is implemented in a UE will be described in greater detail.

[0689] First, in a wireless communication system, a UE for reporting the CSI may comprise a Radio Frequency (RF) module for transmitting and receiving a radio signal; and a processor operatively connected to the RF module.

[0690] The RF module of the UE receives, from the eNB, downlink control (DCI) information that triggers an aperiodic CSI report.

[0691] And the processor controls the UE to determine a CSI reference resource related to the aperiodic CSI report.

[0692] The CSI reference resource can be set to an interval n - ncQi_ref in the time domain.

[0693] The nCQI_ref can be determined based on a first parameter related to the time for computing the CSI.

[0694] And the first parameter can be determined based on a CSI latency and a numerology.

[0695] CSI latency can be represented by a CSI computation delay.

[0696] More specifically, the nCQI_ref can be the smallest value equal to or greater than the floor (a first parameter/a second parameter), so that the n-nCQI_ref range corresponds to a valid downlink range.

[0697] The second parameter can represent the number of symbols within an interval.

[0698] More specifically, the first parameter can be represented by a specific number of symbols (Z'), and the second parameter can be represented by . intervato

[0699] And the second parameter is 14.

[0700] Now, a specific method for computing an nCQI_ref value by the UE will be described with reference to Figure 19.

[0701] In other words, Figure 19 illustrates an example of a method to implement a value of nCQI_ref proposed in this descriptive report.

[0702] First, the memory of a UE stores a second preset parameter.

[0703] And the UE processor can compute the nCQI_ref value using a first input parameter value and a second parameter value stored in memory.

[0704] The first parameter value is determined based on a CSI latency (or CSI computation delay) and a numerology (μ).

[0705] As shown in Figure 19, in the case of latency of CSI 1, if the numerology (μ) is 0, 1, 2 and 3, the first parameter value is 8, 11, 21 and 36, respectively, and the nCQI_ref value corresponding to it is 0, 0, 1 and 2.

[0706] And, in the case of latency of CSI 2-1, if the numerology (μ) is 0, 1, 2 and 3, the first parameter value is 16, 30, 42 and 85, respectively, and the value of nCQI_ref corresponding to it is 1, 2, 3 and 6.

[0707] And, in the case of CSI 2-2 latency, if the numerology (μ) is 0, 1, 2 and 3, the first parameter value is 37, 69, 140 and 140, respectively, and the value of nCQI_ref corresponding to it is 2, 4, 10 and 10.

[0708] And the UE RF module reports the CSI to the eNB in interval n based on the CSI reference resource.

[0709] Additionally, the RF module of the UE receives, from the eNB, an aperiodic CSI-RS.

[0710] And the UE processor computes the CSI based on the aperiodic CSI-RS and the CSI reference resource.

[0711] It is preferred that the UE processor performs the CSI computation before the UE RF module reports the CSI.

[0712] In this document, the aperiodic CSI-RS can be received after the DCI.

[0713] Furthermore, the RF module of the UE can transmit capability information including the first parameter to the eNB before receiving the DCIs.

[0714] DCI can be received in an interval other than interval n.

[0715] With reference to Figures 19 to 23 to be described later, a process by which a method for reporting CSI proposed in this descriptive report is implemented in an eNB will be described in greater detail.

[0716] First, in a wireless communication system, an eNB for receiving a CSI report may comprise a Radio Frequency (RF) module for transmitting and receiving a radio signal; and a processor operatively connected to the RF module.

[0717] First, the eNB RF module transmits downlink control (DCI) information to the UE that triggers an aperiodic CSI report.

[0718] And the eNB RF module receives, from the UE, the aperiodic CSI report in an interval n.

[0719] In the present document, the aperiodic CSI report is related to a CSI reference resource, and the CSI reference resource can be determined for an interval n - ncQi_ref in the time domain.

[0720] At this time, the nCQI_ref can be the smallest value equal to or greater than the floor (a first parameter/a second parameter), so that the n-nCQI_ref range corresponds to a valid downlink range.

[0721] In this document, the first parameter can be related to the time to compute the CSI, and the second parameter can represent the number of symbols in an interval.

[0722] More specifically, the first parameter can be represented by a specific number of symbols (Z'), and the second parameter can be represented by .

[0723] And the second parameter can be 14.

[0724] And the first parameter can be determined based on a CSI latency and a numerology.

[0725] CSI latency can be represented by a CSI computation delay.

[0726] Additionally, the RF module of the UE can transmit an aperiodic CSI-RS to the UE.

[0727] At that time, the aperiodic CSI-RS can be transmitted to the UE after the DCI.

[0728] And the eNB RF module can receive capability information including the first parameter from the UE before transmitting the DCI.

[0729] In this document, DCIs can be transmitted from a range other than range n. The device to which the present invention can be applied in general

[0730] Figure 20 illustrates a block diagram of a wireless communication device to which methods proposed by this descriptive report can be applied.

[0731] Referring to Fig. 20 , a wireless communication system comprises an eNB 2010 and a plurality of UEs 2020 located within range of the eNB 3510.

[0732] The eNB and the UEs can be represented by wireless devices, respectively.

[0733] The eNB comprises a processor 2011, memory 2012 and Radio Frequency (RF) unit 2013. The processor 2011 implements the functions, processes and/or methods described with reference to Figures 1 to 19. The layers of a wireless interface protocol thread can be implemented by the processor. The memory, which is connected to the processor, stores various types of information to operate the processor. The RF unit, which is connected to the processor, transmits and/or receives a radio signal.

[0734] The UE comprises a processor 2021, memory 2022 and RF unit 2023.

[0735] The processor implements the functions, processes and/or methods described with reference to Figures 1 to 19. The layers of a wireless interface protocol can be implemented by the processor. The memory, which is connected to the processor, stores various types of information to operate the processor. The RF unit, which is connected to the processor, transmits and/or receives a radio signal.

[0736] The memory 2012, 2022 can be installed inside or outside the processor 2011, 2021 and can be connected to the processor through various well known means.

[0737] In addition, the eNB and/or the UE can be equipped with a single antenna or multiple antennas.

[0738] The antenna 2014, 2024 performs the function of transmitting and receiving a radio signal.

[0739] Figure 21 illustrates a block diagram of a communication device according to an embodiment of the present invention.

[0740] In particular, Figure 21 provides additional details of the UE of Figure 20.

[0741] With reference to Figure 21, the UE may comprise a processor (or digital signal processor (DSP)) 2110, RF module (or RF unit) 2135, power management module 2105, antenna 2140, battery 2155 , monitor 2115, keyboard 2120, memory 2130, Subscriber Identity Module (SIM) card 2125 (this element is optional), speaker 2145 and microphone 2150. The UE can also include a single antenna or multiple antennas.

[0742] The processor 2110 implements the functions, processes and/or methods described with reference to Figures 1 to 19. The layers of a wireless interface protocol can be implemented by the processor.

[0743] Memory 2130 is connected to the processor and stores information related to processor operation. The memory can be installed inside or outside the processor and can be connected to the processor in a variety of well known ways.

[0744] The user, for example, enters command information such as a telephone number by pressing (or touching) the keyboard button 2120 or by voice activation using the microphone 2150. The processor receives the information from command and processes the command to perform a suitable function such as making a phone call to the phone number. Operational data can be extracted from SIM card 2125 or from memory 2130. In addition, the processor can recognize the user and for the user's convenience, can display command information or operational information on monitor 2115.

[0745] The 2135 RF unit, which is connected to the processor, transmits and/or receives an RF signal. The processor delivers the command information to the RF module to initiate communication, for example to transmit a radio signal comprising voice communication data. The RF module consists of a receiver and a transmitter to receive and transmit a radio signal. The antenna 2140 performs the function of transmitting and receiving a radio signal. Upon receiving a radio signal, the RF module delivers a signal and transforms the signal into baseband so that the processor can process the signal. The processed signal can be converted into auditory information emitted through the 2145 speaker or readable information.

[0746] Figure 22 illustrates an example of an RF module of a wireless communication device to which a method proposed by the present specification can be applied.

[0747] More specifically, Figure 22 illustrates an example of an RF module that can be implemented in a Frequency Division Duplex (FDD) system.

[0748] First, along the transmission path, the processor shown in Figures 20 and 21 processes data to be transmitted and provides an analog output signal to the transmitter 2210.

[0749] Within the transmitter 2210, the analog output signal is filtered by the low pass filter (LPF) 2211 to remove images caused by the analog to digital converter (ADC), upconverted to an RF band from the baseband by mixer 2212, and amplified by variable gain amplifier (VGA) 2213; the amplified signal is filtered by filter 2214, further amplified by power amplifier (PA) 2215, routed through duplexer (or duplexers) 2250/antenna switch (or switches) 2260, and transmitted through antenna 2270.

[0750] In addition, along the receive path, the antenna receives external signals and provides the received signals, which are routed through the antenna switch (or switches) 2260/duplexers 2250 and are provided to the receiver 2220.

[0751] Inside the receiver 2220, the received signal is amplified by the low noise amplifier (LNA) 2223, filtered by the bandpass filter 2224, and downconverted to the baseband from the RF band by the mixer 2225 .

[0752] The down-converted signal is filtered by the low-pass filter (LPF) 2226, amplified by the VGA 2227 to acquire the analog input signal, which is supplied to the processor illustrated in Figures 20 and 21.

[0753] Furthermore, the local oscillator (LO) 2240 generates transmit and receive LO signals and provides the generated signals to the upconverter 2212 and downconverter 2225, respectively.

[0754] In addition, the phase-locked loop (PLL) 2230 receives control information from the processor to generate transmit and receive LO signals at suitable frequencies and provides the control signals to the LO generator 2240.

[0755] In addition, the circuits shown in Figure 22 can be arranged differently from the structure of Figure 22.

[0756] Figure 23 illustrates another example of an RF module of a wireless communication device to which a method proposed by this specification can be applied.

[0757] More specifically, Figure 23 illustrates an example of an RF module that can be implemented in a Time Division Duplex (TDD) system.

[0758] The transmitter 2310 and the receiver 2320 of the RF module in the TDD system have the same structures as those of a transmitter and a receiver of an RF module in the FDD system.

[0759] Below, only the structure of the RF module in the TDD system that exhibits a difference from the RF module in the FDD system will be illustrated, and the same structure will be described with reference to Figure 22.

[0760] A signal amplified by the power amplifier 2315 of the transmitter is routed through the band selection switch 2350, band pass filter (BPF) 2360 and the antenna switch (or switches) 2370; and is transmitted through antenna 2380.

[0761] In addition, along the reception path, the antenna receives external signals, provides the received signals. Signals are routed through the antenna switch (or switches) 2370, BPF 2360, and band selection switch 2350; and are provided to receiver 2320.

[0762] The embodiments described above are combinations of elements and constituting resources of the present invention in a predetermined form. Each individual element or feature is to be considered optional, except where explicitly stated otherwise. Each individual element or feature can be implemented on its own, without being combined with other elements or features. Furthermore, it is also possible to construct embodiments of the present invention by combining a portion of the elements and/or resources. A portion of a structure or resource of one embodiment may be included in another embodiment or may be replaced by the corresponding structure of the resource of another embodiment. It should be clearly understood that claims which are not explicitly cited within the technical scope of the present invention may be combined to form an embodiment or may be included in a new claim by an amendment after filing.

[0763] Embodiments of the present invention can be implemented by various means such as hardware, firmware, software, or a combination thereof. In the case of hardware implementation, an embodiment of the present invention may be implemented using one or more of ASICs (Application Specific Integrated Circuits), DPSs (Digital Signal Processors), DSPDs (Digital Signal Processing Devices), PLDs (Programmable Logic Devices), FPGAs (Field Programmable Gate Arrays), processors, controllers, microcontrollers and microprocessors.

[0764] In the case of implementation by firmware or software, an embodiment of the present invention can be implemented in the form of modules, procedures, functions and the like that perform the functions or operations described above. Software codes can be stored in memory and activated by the processor. The memory can be located inside or outside the processor and can exchange data with the processor using various well known means.

[0765] It is clear to those skilled in the art that the present invention can be embodied in other specific forms without departing from the essential characteristics of the present invention. Therefore, the above detailed descriptions should be considered to be illustrative rather than restrictive in all respects. The technical scope of the present invention is to be determined by a reasonable interpretation of the appended claims, and all modifications covered by an equivalent scope of the present invention belong to the technical scope of the present invention.

INDUSTRIAL APPLICABILITY

[0766] This document discloses a method for reporting CSI in a wireless communication system with examples based on the 3GPP LTE/LTE-A system and the 5G system (New RAT System); however, the present invention can be applied to various other types of wireless communication systems besides the 3GPP LTE/LTE-A system and the 5G system.

Claims (16)

1. Method for reporting, via a user equipment (UE) (2020), channel state information (CSI) in a wireless communication system, the method comprising: receiving (S1710), via the UE (2020) and from a base station (BS) (2010), downlink control (DCI) information relating to an aperiodic CSI report to be performed by the UE (2020) at an interval »; determine, through the UE (2020), a value nco;,.?;.- based on a number of symbols T related to a time for computing the CSI; determining (S1720), via the UE (2020), a CSI reference resource as being an n - nco range; in a time domain that should be used for the aperiodic CSI report; and transmitting (S1730), through the UE (2020) and to the BS (2010), the aperiodic CSI report in interval n, based on the CSI reference resource being the interval - nco;,.,f, CHARACTERIZED by fact that the nco; is a smaller value greater than so that the interval satisfies valid downlink interval criteria, and where is a floor function and range is a number of symbols in a range. 2. Method, according to claim 1, CHARACTERIZED by the fact that the valid downlink interval criteria are based on at least (i) the number of symbols Z' related to the time to compute the CSI and (ii) a time of DCI processing. 3. Method, according to claim 1, CHARACTERIZED by the fact that : is equal to 14 symbols in a range. 1 break 4. Method, according to claim 1, characterized by the fact that it additionally comprises: receiving, from the BS (2010), an aperiodic reference signal (CSI-RS) in the CSI reference resource, interval n - nco ; r?f; determine the CSI based on the aperiodic CSI-RS; and generate the aperiodic CSI report based on the CSI. 5. Method according to claim 1, CHARACTERIZED by the fact that it further comprises: determining the number of time-related Z symbols to compute the CSI based on a CSI complexity and a subcarrier spacing. 6. Method, according to claim 1, CHARACTERIZED by the fact that determining the value based on the number of time-related Z symbols to compute the CSI comprises: determining the value nco; ;,r based on the number of time-related Z symbols to compute the CSI, and additionally based on a number of symbols in a range. 7. Method, according to claim 1, CHARACTERIZED by the fact that receiving the DCI comprises: receiving the DCI at an interval other than the interval n, in which the aperiodic CSI report must be carried out. 8. Method, according to claim 1, CHARACTERIZED by the fact that, based on the value ,.ff- being equal to zero, the aperiodic CSI report is carried out at the same interval as the receipt of the DCI. 9. User equipment (UE) (2020) configured to report channel state information (CSI) in a wireless communication system, the UE (2020) comprising: a radio frequency (RF) module (2023) configured to transmit and receive radio signals; at least one processor (2021); and at least one computer memory (2022) operably connectable to the at least one processor (2021) and which stores instructions that, when executed, cause the at least one processor (2021) to perform operations comprising: receiving (S1710), via the RF module (2023) and from a base station (BS) (2010), downlink control (DCI) information relating to an aperiodic CSI report to be performed by the UE (2020) in a interval "; determine, through the UE (2020), a value nco;,.?;.- based on a number of symbols T related to a time for computing the CSI; determining (S1720), via the UE (2020), a CSI reference resource as being an n - nco range; in a time domain that should be used for the aperiodic CSI report; and transmitting (S1730), via the RF module (2023) and to the BS (2010), the aperiodic CSI report in interval n, based on the CSI reference resource being interval n - ;.,5, CHARACTERIZED by the fact that o is a smaller greater value or so that the interval satisfies valid downlink interval criteria, and where J is a floor function and range is a number of symbols in a range. 10. User equipment (2020), according to claim 9, CHARACTERIZED by the fact that the valid downlink interval criteria are based on at least (i) the number of time-related symbols 1 to compute the CSI and ( ii) a DCI processing time. 11. User equipment (2020), according to claim 9, CHARACTERIZED by the fact that: - is equal to 14 symbols in a range. 12. User equipment (2020), according to claim 9, CHARACTERIZED by the fact that the operations additionally comprise: receiving, through the RF module (2023) and from the BS (2010), a reference signal aperiodic (CSI-RS) on CSI reference resource, range n ~ nCQl_ref > determine CSI based on aperiodic CSI-RS; and generate the aperiodic CSI report based on the CSI. 13. User equipment (2020), according to claim 9, CHARACTERIZED by the fact that determining the number of time-related Z' symbols to compute the CSI comprises: determining the number of time-related Z' symbols to compute the CSI based on a CSI complexity and a subcarrier spacing. 14. User equipment (2020), according to claim 9, CHARACTERIZED by the fact that determining the value ,.£ based on the number of symbols Z' related to time to compute the CSI comprises: determining the value based on the number of Z' symbols and additionally based on information related to a subcarrier spacing. 15. User equipment (2020), according to claim 9, CHARACTERIZED by the fact that receiving the DCI comprises: receiving the DCI at an interval other than the interval n, in which the aperiodic CSI report must be performed. 16. User equipment (2020), according to claim 9, CHARACTERIZED by the fact that, based on the value being equal to zero, the aperiodic CSI report is carried out at the same interval as the receipt of the DCI.