Method and apparatus for omitting channel status information (CSI) in a linear coupling port selection codebook

Abstract

A channel state information CSI report by a user equipment UE. Based on a received CSI report configuration, determine (402) a rank index of a precoder vector or matrix, a number of precoder coefficients of the RI transmission layer. Group (403) the precoder coefficients of the RI transmission layer into two or more coefficient subsets, each coefficient subset comprising a plurality of precoder coefficients. Assign (404) a predefined ordering to the two or more coefficient subsets and the precoder coefficients within each coefficient subset. Split (405) the two or more coefficient subsets into two or more CSI groups with associated priority levels. Generate (406) a CSI report comprising a CSI part 1 and a CSI part 2. The CSI part 1 has a fixed payload size and comprises information indicative of a payload size of the CSI part 2. The CSI part 2 comprises precoder coefficients of at least one of the two CSI groups.

Description

[Technical Field]

[0001] This disclosure relates to the field of wireless communication. More specifically, to uplink channel information (uplink control information UCI) for codebook-based precoding in wireless communication systems, or to channel state information CSI omission schemes (omission schemes) for channel state information CSI feedback reporting. Some embodiments relate to a user device (UE) and a method performed by the user device UE for channel state information CSI reporting. Some other embodiments relate to a network node and a method performed by the network node to receive channel state information CSI reports generated by the user device UE. [Background technology]

[0002] The fifth-generation (5G) mobile communication system, also known as New Radio (NR), offers a higher level of performance than previous generations of mobile communication systems. 5G mobile communications have been driven by the need to provide ubiquitous connectivity to diverse applications such as diverse automotive communications, remote control with feedback, video downloads, Internet of Things (IoT) devices, and data applications like machine-type communication (MTC) devices. 5G radio technology brings several key advantages, including higher speeds, reduced latency, and improved connectivity. The Third Generation Partnership Project (3GPP®) has provided a complete system specification for a 5G network architecture that includes at least a Radio Access Network (RAN), Core Transport Network (CN), and Service Functions.

[0003] Figure 1 shows a simplified schematic diagram of an example of a wireless communication network 100, comprising a core network (CN) 110 and a radio access network (RAN) 120. The RAN 120 is shown to have multiple network nodes or radio base stations, which are called base station gNBs in 5G. Three radio base stations gNB1, gNB2, and gNB3 are depicted. Each base station gNB provides service to an area called a coverage area or cell. Figure 1 shows three cells 121, 122, and 123, each provided service by its own base station gNBs, gNB1, gNB2, and gNB3. Network 100 can have any number of cells and base station gNBs. A radio base station or network node provides service to users within a cell. In 4G or LTE, a radio base station is called an eNB, in 3G or UMTS, a radio base station is called an eNodeB, and in other radio access technologies, it is called a BS. A user or user equipment (UE) is a radio terminal device, mobile terminal device, or stationary communication device. Mobile terminal devices (UEs), or user equipment, may also include IoT devices, machine-type communication devices (MTCs), and other similar devices. IoT devices include wireless sensors, software, actuators, and computer devices. These devices can be embedded in mobile devices, automobiles, industrial equipment, environmental sensors, medical devices, and aerospace vehicles, and they also possess network connectivity that allows them to collect and exchange data across existing network infrastructures.

[0004] Returning to Figure 1, each cell contains user equipment UEs and IoT devices. Base station gNB1 in cell 121 provides services to user equipment UE1_121A, user equipment UE2_121B, and IoT device 121C. Similarly, base station gNB2 in cell 121 provides services to user equipment UE3_122A, user equipment UE4_122B, and IoT device 122C. Base station gNB3 in cell 123 provides services to user equipment UE5_123A, user equipment UE6_123B, and IoT device 123C. Network 100 can have any number of user equipment UEs and IoT devices, or any other type of device. Devices communicate with the serving base station gNB(s) on the uplink, and the base station gNB(s) communicate with the devices on the downlink. Each base station gNB1 to base station gNB3 may be connected to the core network CN120 via, for example, the S1 interface and their respective backhaul links 111, 121D, 122D, and 123D, which are schematically represented in Figure 1 by arrows pointing to the "core". The core network CN120 may be connected to one or more external networks, such as the internet. Base station gNBs may be connected to each other via the S1 interface, X2 interface, or XN interface in 5G and their respective interface links 121E, 122E, and 123E, which are represented in the figure by arrows pointing to the base station gNBs.

[0005] A physical resource grid may be used for data transmission. The physical resource grid may consist of a set of resource elements (REs) to which various physical channels and physical signals are mapped. For example, physical channels may include physical downlink, uplink, and / or sidelink (SL) shared channels (physical downlink shared channel PDSCH, physical uplink shared channel PUSCH, physical sidelink shared channel PSSCH) that carry user-specific data, also known as downlink, uplink, or sidelink payload data, and physical broadcast channels (PBCH) that transmit, for example, master information blocks (MIBs) and system information blocks (SIBs), and physical downlink control channels, physical uplink control channels, and / or physical sidelink control channels (PDCCH, PUCCH, PSCCH) that transmit, for example, downlink control information (DCI), uplink control information (UCI), or sidelink control information (SCI). In the case of uplink, the physical channel may further include a physical random access channel (PRACH or RACH) that the user equipment UE uses to access the network once it is synchronized and has obtained the Master Information Block (MIB) and Master Information Block (SIB). The physical signal consists of a reference signal (RS), a synchronization signal (SS), and so on. The resource grid may consist of frames or radio frames that have a predetermined duration in the time domain, such as 10 milliseconds, or a predetermined bandwidth in the frequency domain. A radio frame may have a predetermined number of subframes with a predetermined length, for example, two subframes with a length of 1 millisecond. Each subframe may have two slots of OFDM symbols, the number of which corresponds to the cyclic prefix (CP) length. In 5G, each slot consists of 14 OFDM symbols or 12 OFDM symbols, based on a normal cyclic prefix CP and an extended cyclic prefix CP, respectively.For example, frames may consist of fewer OFDM symbols, such as when using a short transmission time interval (TTI) or a mini-slot / non-slot-based frame structure composed of several OFDM symbols. 5G new wireless NR supports slot aggregation, allowing data transmission to be scheduled across one or more slots. The slot format display informs the user equipment UE whether the OFDM symbols are downlink, uplink, or flexible.

[0006] The wireless communication network system may be any single-tone or multi-carrier system using frequency division multiplexing, such as an orthogonal frequency division multiplexing (OFDM) system, an orthogonal frequency division multiplexing access (OFDMA) system, or other IFFT-based signals with or without a cyclic prefix CP, e.g., Discrete Fourier Transform DFT-OFDM. Other waveforms, such as non-orthogonal waveforms for multiplex access, e.g., filtered bank multicarrier (FBMC), generalized frequency division multiplexing (GFDM), or universal filtering multicarrier (UFMC), may be used. The wireless communication system can operate, for example, according to the LTE-Advanced Pro standard or 5G or new radio NR (New Radio) standard.

[0007] The wireless communication network system depicted in Figure 1 may be a heterogeneous network having two different overlay networks, where each macrocell has a network of macrocells with macro base stations such as base stations gNB1 to gNB3, and a network of small cell base stations such as femtocells or picocells (not shown in Figure 1). In addition to the wireless networks described above, there are also non-terrestrial wireless communication networks that have space-borne transceivers such as satellites and / or air-borne transceivers such as unmanned aerial vehicle systems. Non-terrestrial wireless communication networks or systems can operate in a similar manner to the terrestrial systems described above, with reference to Figure 1, for example, according to the LTE-advancedpro standard or 5G or new wireless NR standard.

[0008] In wireless communication network systems like the one schematically depicted in Figure 1, multi-antenna technology may be used to improve user data rate, link reliability, cell coverage, and network capacity, for example, according to LTE, new wireless NR, or other communication systems. Linear precoding is used in the physical layer of the communication system to support multi-stream or multi-layer transmission. Linear precoding is performed by a precoder matrix that maps the data layer to the antenna port. This precoding can be considered a generalization of beamforming, a technique that spatially directs or concentrates data transmission toward the intended receiver. The precoder matrix used by the base station gNB to map the data to the transmitting antenna port is determined using channel state information (CSI).

[0009] In wireless communication network systems such as LTE or new radio (5G), as described above, the downlink signal transmits data signals, control signals containing downlink DL control information (DCI), and a number of reference signals or reference symbols (RS) used for different purposes. A gNodeB (or base station gNB or base station) transmits data and downlink control information (DCI) via the so-called physical downlink shared channel (PDSCH) and physical downlink control channel (PDCCH) or extended physical downlink control channel PDCCH (ePDCCH), respectively. Furthermore, the downlink signal of a base station gNB may include one or more types of reference signals (RS), including the LTE common reference signal (CRS), channel status information reference signal (CSI-RS), demodulation reference signal (DM-RS), and phase tracking reference signal (PT-RS). The common reference signal CRS is transmitted over the downlink DL system bandwidth portion and used by user equipment (UE) to obtain channel estimates for demodulating data or control information. The Channel State Information Reference Signal (CSI-RS) is transmitted with lower density in the time and frequency domains compared to the Common Reference Signal (CRS), and is used by user equipment UEs for channel estimation or acquisition of Channel State Information (CSI). The Demodulation Reference Signal (DM-RS) is transmitted only within the bandwidth portion of each physical downlink shared channel (PDSCH), and is used by user equipment UEs for data demodulation. Several Channel State Information Reference Signal (CSI-RS) reporting mechanisms are used for signal precoding at base station gNBs, including reporting of unprecoded Channel State Information Reference Signals (CSI-RS) and beamforming Channel State Information Reference Signals (CSI-RS). In the case of unprecoded Channel State Information Reference Signals (CSI-RS), a one-to-one mapping is used between the Channel State Information Reference Signal (CSI-RS) port and the transceiver unit (TXRU) of the antenna array at the base station gNB. Therefore, unprecoded Channel State Information Reference Signals (CSI-RS) provide cell-wide coverage, where different Channel State Information Reference Signal (CSI-RS) ports have the same beam direction and beam width.In the case of beamforming / precoded user-device UE-specific or non-user-device UE-specific channel state information reference signals (CSI-RS), applying beamforming operation on a single antenna port or multiple antenna ports results in the formation of multiple narrow beams with high gain in different directions, making it impossible to cover the entire cell.

[0010] In wireless communication systems employing Time Division Duplexing (TDD), channel status information (CSI) is made available to the base station (gNB) through channel reciprocity. However, in the case of Frequency Division Duplexing (FDD), there is no channel reciprocity, so the channel is estimated at the user equipment UE, and this estimation is fed back to the base station gNB. Figure 2 shows a block-based model of MIMODL transmission using codebook-based recoding, compliant with LTE Release 8. Figure 2 schematically shows a base station 200 (gNB), a user equipment (UE) 202, and a channel 204, such as a radio channel for radio data communication between the base station 200 and the user equipment 202. The base station has multiple antennas or antenna arrays ANT T The system includes a precoder 206 that receives a data vector 208 and a precoder matrix F from a codebook 210. Channel 204 may be described by a channel tensor / matrix 212. User equipment 202 is an antenna or antenna array ANT having multiple antennas or antenna elements. R The data vector 214 is received via this channel. A feedback channel 216 is provided between the user device 202 and the base station 200 for transmitting feedback information. In previous releases of 3GPP® up to Release 15, the use of multiple downlink reference signals (such as the channel state information reference signal CSI-RS) for channel state information CSI estimation in the user device UE is supported.

[0011] In frequency division duplex FDD systems (up to release 15), the channel estimated by the user equipment UE is implicitly reported to the base station gNB. Therefore, the channel status information CSI report transmitted by the user equipment UE via the feedback channel includes a rank index (RI), a precoding matrix index (PMI), and a channel quality index (CQI) (CRI from release 13). Thus, the base station gNB can determine the precoding row example and the modulation order and coding scheme (MCS) of the symbols to be transmitted. The precoding matrix index PMI and rank index RI are used to determine the precoding matrix from a predefined set of matrices Ω, also called a codebook. The codebook may be a lookup table with a matrix for each entry in the table, for example, according to LTE. Therefore, the precoding matrix index PMI and rank index RI from the user equipment UE determine which rows and columns of the table to use for the precoder matrix. The precoder and codebook are N1 dual-polarized antennas (total N t A one-dimensional uniform linear array (ULA) with 2N1 antennas, or dual-polarized antennas (total N) at N1N2 positions. tUp to Release 15, a two-dimensional uniform planar array (UPA) with 2N1N2 antennas has been designed for base station gNBs. Uniform linear arrays (ULAs) allow for horizontal (azimuth) radio wave control only, thus enabling azimuth-only beamforming in base station gNBs, whereas uniform planar arrays (UPAs) support transmit beamforming in both vertical (elevation) and horizontal (azimuth) directions, and are therefore also called full-dimensional (FD) MIMO. The codebook may be a set of beamforming weights that use the array response vector of the array to form spatially separated electromagnetic transmit and receive beams, for example, in the case of a huge antenna array such as full-dimensional FD-MIMO. The beamforming weights of the array (also called array steering vectors) are amplitude gain and phase adjustments applied to the signal fed to the antenna (or the signal received from the antenna) in order to transmit (or receive) radiation toward (or from) a particular direction. The components of the precoder matrix are obtained from the codebook, and the precoding matrix index PMI and rank index RI are used to obtain the precoder while reading the codebook. When a uniform linear array (ULA) or uniform planar array (UPA) is used for signal transmission, the array steering vector may be described by columns of a two-dimensional discrete Fourier transform (DFT) matrix.

[0012] The precoder matrix used in the Type I and Type II channel state information CSI report schemes of 3GPP (registered trademark) New Radio Release 15 is defined in the frequency domain and has a dual-stage structure (i.e., a codebook of two components). F(s)=F1F2(s), s = 0, …, S - 1, where S represents the number of subbands. F is in bold notation. The first component, the so-called first-stage precoder F1, is used to select a number of beam vectors and rotation oversampling coefficients from a discrete Fourier transform (DFT)-based matrix, also called a spatial codebook. Further, the first-stage precoder F1 corresponds to a broadband matrix that does not depend on the subband index s, and is composed of L selected spatial beamforming vectors (so-called spatial beams) b l ∈C (N1N2×1) , l = 0, …, L - 1. The subscript of b l is the lowercase letter l. C is in hollow notation. The exponent of C is specifically N1N2×1 (one).

[0013]

Number

[0014] The first component, the so-called first-stage precoder F1, is used to select a number of spatial regions (SDs) or beam vectors, and rotation oversampling coefficients from a discrete Fourier transform (DFT)-based matrix, also called a spatial codebook. The spatial codebook is configured with an oversampled discrete Fourier transform DFT matrix of dimension N1N2×N1O1N2O2, where O1 and O2 each indicate an oversampling coefficient for the first and second dimensions of the codebook. The discrete Fourier transform DFT vectors in the codebook are grouped into (q1,q2), 0≦q1≦O1-1, 0≦q2≦O2-1 subgroups, and each subgroup has N1N2 discrete Fourier transform DFT vectors. The parameters q1 and q2 are shown as rotation oversampling coefficients for the first and second dimensions of the antenna array, respectively.

[0015] The second component, the so-called second-stage precoder F2(s), is used to combine the selected beam vectors. That is, the second-stage precoder F2(s) corresponds to a selection / combination / cophasing matrix for selecting / combining / cophasing the beams defined by F1 for the s-th set subband. For example, in the case of rank-1 transmission and type-I channel state information CSI report, F2(s) is given as follows for a dual-polarized antenna array.

[0016]

Equation

[0017] Here, e u ∈C L×1 has zeros at all positions except the u-th position, which is 1. This definition of e selects the u-th vector of F1 for each polarization of the antenna. Further, e u (where the exponent of e is jδ jδ1 l) is the quantized phase adjustment for the second polarization of the antenna array. For example, in the case of rank 1 transmission and type II channel state information CSI report, F2(s) is given as follows for a dual-polarization antenna array:

[0018]

number

[0019] Here, p l and e j δ l ,l=0,1,2,…,2L-1 are the beam coupling coefficients for quantized amplitude and phase, respectively. In rank-R transmission, F2(s) has R vectors. R represents the transmission rank, and the entries in each vector are chosen to couple one or more beams within each polarization.

[0020] The selection of matrices F1 and F2(s) is performed by the user equipment UE based on a reference signal such as the channel state information reference signal CSI-RS and knowledge of the channel state. The selected matrices are shown in the channel state information CSI report in the form of a rank index RI (where the rank index RI represents the rank of the precoding matrix) and a precoding matrix index PMI, and are used in the base station gNB to update the multi-user precoder for the next transmission time interval.

[0021] For 3GPP® Release 15 Dual-Stage Type II Channel State Information CSI Report, F2 = [F2 (r) (0), ..., F2 (r) (s), ..., F2 (r)The second-stage precoder F2(s) is calculated on a subband basis, such that the number of columns in (S-1) depends on the number S of configured channel quality index CQI subbands. Here, a subband refers to a group of adjacent physical resource blocks (PRBs). A drawback of Type II channel state information CSI feedback is the large feedback overhead required to report the coupling coefficients on a subband basis. The feedback overhead is almost linear with respect to the number of subbands, so it becomes quite large when there are many subbands.

[0022] To overcome the high feedback overhead of the Release 15 Type II Channel State Information CSI reporting scheme, 3GPP® RAN#81 has decided to study a feedback compression scheme for the second-stage precoder F2. Several contributions have demonstrated that transforming F2 into a transformation region called the delay region using a small set of discrete Fourier transform (DFT) based basis vectors can dramatically reduce the number of beam coupling coefficients in F2. The corresponding three-stage precoder is a three-stage (i.e., three-component) F1F2 (r) F3 (r) This is the codebook. The first component, represented by matrix F1, is identical to the new radio NR component of Release 15, is independent of the transmitting layer (r), and has a number (numerous, number of) of spatial domain (SD) basis vectors selected from the spatial codebook. Matrix F3 (r) The second component, represented by , is layer-dependent and is used to select the number (numerous, number of) delay-domain (DD) basis vectors from a Discrete Fourier Transform-based (DFT-based) matrix, also known as the delay codebook. The third component is matrix F2 (r) It is represented as such and has a number of coupling coefficients (numerous, number of) used to combine spatial domain SD basis vectors and delayed domain DD basis vectors selected from the spatial codebook and delayed codebook, respectively.

[0023] Assuming rank R transmission, the three-component precoder matrix or channel state information CSI matrix for 2N1N2 configured antenna / channel state information reference signal CSI-RS ports and S configured subbands can be expressed as follows for the first polarization between the antenna ports and the r-th transmission layer:

[0024]

number

[0025] The second polarization between the antenna port and the r-th transmission layer is expressed as follows:

[0026]

number

[0027] Here, b u (l=0,…,L-1) represents the u-th spatial domain SD basis vector selected from the spatial codebook. d (r) (d=0,…,D-1) represents the d-th delay region DD basis vector associated with the r-th layer selected from the delay codebook. γ p,l,d (r) α represents the complex delay-domain coupling coefficient associated with the u-th spatial domain SD basis vector, the d-th delay-domain DD basis vector, and the p-th polarization. D represents the number of constructed delay-domain DD basis vectors. (r) This represents a normalized scalar.

[0028] The advantage of the three-component channel state information CSI reporting scheme in the above formula is that the feedback overhead for reporting the coupling coefficients of the precoder matrix or channel state information CSI matrix becomes independent of the number of configured channel quality index CQI subbands (i.e., independent of system bandwidth). For this reason, the above three-component codebook was recently adopted in the 3GPP® Release 16 Dual-Stage Type II Channel State Information CSI Reporting Specification.

[0029] Current 3GPP® Type I and Type II channel status information CSI reporting schemes are primarily used in frequency division duplex (FDD) system configurations and therefore do not utilize the characteristics of uplink / downlink channel reciprocity. Conversely, channel reciprocity is primarily applied in time division duplex (TDD) systems, where the same carrier is used for uplink and downlink transmissions. Channel measurements performed on the uplink of a base station (gNB) may be used to support downlink transmissions such as downlink beamforming, with or without additional feedback from user equipment (UE). [Prior art documents] [Patent Documents]

[0030] [Patent Document 1] European Patent Application Publication No. 3734852 [Overview of the project] [Problems that the invention aims to solve]

[0031] In frequency-division duplex FDD systems, channel reciprocity is usually not satisfied because the duplex distance between the uplink and downlink carriers may be greater than the channel coherence bandwidth. Even in frequency-division duplex FDD systems, known approaches to obtaining channel status information (CSI) at the base station without the assistance of user equipment (UE) are based on channel extrapolation. There, it is assumed that the downlink channel and / or its multipath parameters are calculated by extrapolating the channel response (or its multipath parameters) measured at the uplink. However, measurement results have shown that such extrapolation is not only inaccurate but can lead to inaccurate results, particularly with respect to the phase of the multipath component of the channel. Recently, it has been found that in various scenarios, the spatial and delay characteristics of the uplink and downlink channel responses in frequency-division duplex FDD systems are strongly correlated, and therefore the channel can be considered a partial reciprocal (interrelated, reciprocal) with respect to the angle(s) and delay(s) of the multipath component.

[0032] In the current Release 16 Type II Channel State Information CSI report, the user equipment UE needs to calculate a set of beam or beamforming vectors, a set of delay or delay vectors, and a set of precoder coefficients for the selected beam and delay of the precoder matrix. However, this increases the complexity of the precoder calculation and the feedback overhead of the Channel State Information CSI report. Furthermore, the calculation and reporting of beams and delays are based on a codebook with limited resolution. That is, the angle and delay information of the multipath components of the channel is only available to the base station or network node at reduced resolution due to quantization by the codebook. As a result, the performance of the corresponding precoded downlink transmission using the precoder coefficients reported by the user equipment UE is reduced.

[0033] Uplink control information (UCI) omissions occur when the uplink resources provided by the base station or network node to the user equipment for uplink transmission are insufficient to transmit the entire content of one or more channel status information CSI reports. Specifically, the base station or network node provides the user equipment UE with a resource allocation for uplink transmission of one or more channel status information CSI reports via a downlink channel (e.g., a physical downlink control channel PDCCH). Uplink transmission may be performed by the user equipment UE via a physical uplink control channel PUCCH or a physical uplink shared channel PUSCH. If the resource allocation provided by the base station to the user equipment is insufficient, the user equipment may drop (delete) portions of and / or one or more channel status information CSI reports used for uplink transmission. For example, a base station may allocate resources to a rank 1 (rank index RI=1) channel status information CSI report, but the user equipment UE may decide to transmit a rank 2 report and report a rank 2 (rank index RI=2) channel status information CSI report that is larger than the size of the allocated resources (e.g., physical uplink shared channel PUSCH resources).

[0034] In such cases, the user equipment UE needs to remove (drop) or omit parts of the channel status information CSI content in one or more channel status information CSI reports. In channel status information CSI reporting schemes that depend on channel angle and delay information at the base station, there is no uplink control information UCI omission procedure for channel status information CSI reports; therefore, a new uplink control information UCI omission procedure is required.

[0035] Therefore, since the known solutions described above have drawbacks, the present invention addresses these drawbacks. [Means for solving the problem]

[0036] The object of the embodiments described herein is to provide an apparatus and method for reporting channel state information CSI feedback for codebook-based precoding in wireless communication networks such as advanced 5G networks.

[0037] According to some embodiments of this specification, a method is provided, performed by user equipment, for generating and reporting a channel status information CSI report in a wireless communication system, the method comprising: receiving a channel status information CSI report configuration from a network node; determining the number of precoder coefficients (an number of precoder coefficients) of the rank index (RI) transmitting layer of a precoder vector or matrix based on the received channel status information CSI report configuration; grouping the rank index RI transmitting layer precoder coefficients into at least two coefficient subsets, each coefficient subset comprising a plurality of precoder coefficients; assigning an ordering to the at least two coefficient subsets, as well as assigning an ordering to the precoder coefficients within each coefficient subset; dividing the at least two coefficient subsets into two or more channel status information CSI groups having associated priority levels; and generating a channel status information CSI report comprising channel status information CSI part 1 and channel status information CSI part 2. Channel Status Information CSI Part 1 not only has a fixed payload size but also contains information indicating the payload size of Channel Status Information CSI Part 2. Channel Status Information CSI Part 2 contains precoder coefficients for at least one of two Channel Status Information CSI groups. The process involves transmitting uplink control information (UCI) containing the Channel Status Information CSI report to a network node via an uplink (UL) channel. These steps are included.

[0038] According to another aspect of some embodiments herein, a method is provided for a wireless communication system to be performed by a network node to receive a channel state information CSI report generated by a user device UE, the method comprising: transmitting a channel state information CSI report configuration to the user device UE so that the number (numerous, number of) of precoder coefficients in the rank index RI transmission layer of a precoder vector or matrix can be determined based on the channel state information CSI report configuration transmitted by the user device UE; receiving uplink control information UCI from the user device UE via an uplink channel, the UCI having a channel state information CSI report generated by the user device UE; the channel state information CSI report comprising channel state information CSI part 1 and channel state information CSI part 2; channel state information CSI part 1 having a fixed payload size as well as information indicating the payload size of channel state information CSI part 2; channel state information CSI part 2 comprising precoder coefficients of at least one group of two or more channel state information CSI groups; the precoder coefficients are ordered into at least two ordered coefficient subsets.

[0039] According to another aspect of some embodiments herein, a user device UE is provided comprising a processor and a memory having instructions executable by the processor, thereby the user device UE is provided by method claims 1 to 1 5 It is operable or configured to perform any one of the embodiments presented in the detailed description relating to the operations performed by the user device UE, such as the one shown.

[0040] According to yet another embodiment of the embodiments herein, a network node is provided comprising a processor and a memory having instructions executable by the processor, thereby the network node is provided, at least according to method claim 1 6It is operable or configured to perform any one of the embodiments presented in the detailed description relating to the network node, such as the one shown.

[0041] Also provided is a computer program that, when executed on at least one processor of a user device UE, comprises instructions causing at least that one processor to perform an action or method step presented herein.

[0042] Also provided is a computer program that, when executed on at least one processor of a network node, comprises instructions causing at least that one processor to perform the method steps presented herein.

[0043] Carriers containing computer programs are also provided. A carrier is one of the following: a computer-readable storage medium, an electronic signal, an optical signal, or a wireless signal. The advantages achieved by embodiments of the present invention include a significant reduction in feedback overhead and computational complexity in user equipment for codebook-based channel status information CSI reports, assuming that information on the angle and delay of the multipath components of the channel is available at the base station.

[0044] Next, embodiments of the present invention will be described in more detail with reference to the accompanying drawings. [Brief explanation of the drawing]

[0045] [Figure 1] A schematic diagram of a wireless communication system. [Figure 2] A diagram illustrating a block-based model of MIMO downlink DL transmission using codebook-based precoding in accordance with LTE Release 8. [Figure 3]A schematic diagram of a wireless communication system for communicating information between a transmitter capable of operating according to the teachings of the present invention as described herein and a plurality of receivers capable of operating according to the teachings of the present invention as described herein. [Figure 4] A flowchart of method steps performed by a user device UE, according to some embodiments of this specification. [Figure 5] A table illustrating the relationship between indexing based on local port indexes and precoder coefficients of coefficient subsets of layer 0 and layer 1, according to exemplary embodiments herein. [Figure 6] Another table illustrating the relationship between a global port index based on a local port index and a selected precoder coefficient for layer 0, according to another exemplary embodiment of this specification. [Figure 7] Another table illustrating the relationship between a global port index based on local port indices and selected precoder coefficients of coefficient subsets for layer 0 and layer 1, according to yet another exemplary embodiment herein. [Figure 8] Another table illustrating the relationship between a global port index based on a local port index and a selected precoder coefficient for layer 0, according to another exemplary embodiment of this specification. [Figure 9] A simplified block diagram showing user equipment according to several embodiments described herein. [Figure 10] A simplified block diagram showing network nodes according to some embodiments of this specification. [Modes for carrying out the invention]

[0046] In the following sections, to facilitate a clearer understanding of the solutions(s) described herein, a detailed description of exemplary embodiments will be provided in several scenarios, accompanied by drawings. The invention according to this embodiment addresses the drawbacks described above. In detail, it is assumed that channel angle and delay information and / or the Doppler component of the multipath component are available at the base station or network node. Then, a method is proposed to significantly reduce the feedback overhead for omitting the codebook-based channel status information CSI report and uplink control information UCI or channel status information CSI based on the linear coupling port selection codebook, as well as the computational complexity in user equipment.

[0047] In general, according to some non-limiting exemplary effects achieved by embodiments herein, the base station gNB or network node includes angle and delay information obtained from the user equipment UE by uplink channel sounding measurements. This is then used to precode / beamform a set of channel state information reference signal CSI-RS resources. The precoded / beamformed channel state information reference signal CSI-RS resources are used for downlink channel measurements and channel state information CSI calculations in the user equipment UE. Based on the downlink measurements of the precoded / beamformed channel state information reference signal CSI-RS, the user equipment UE calculates and reports a set of complex precoder coefficients for a set antenna port. The user equipment UE only needs to determine the set of precoder coefficients for a set antenna port. Unlike Type II channel state information CSI reports, there is no need to calculate beam and delay for the precoder matrix. Thus, the complexity of precoder calculations and the feedback overhead of channel state information CSI reports can be significantly reduced. Furthermore, while the angle and delay information of the channel's multipath components is available at high resolution at the base station (or network node of the base station gNB), it is not quantized in the codebook and is not reported from the user equipment UE. Therefore, the performance of the corresponding precoded downlink transmission using precoder coefficients reported from the user equipment UE will be significantly higher than the performance achieved with the current Release 15 or Release 16 Type II channel state information CSI reporting scheme.

[0048] In general, according to some non-limiting exemplary effects achieved by embodiments herein, the base station gNB or network node includes angular and delay information, as well as / or Doppler information, obtained from the user equipment UE by uplink channel sounding measurements. This is then used to precode / beamform a set of channel state information reference signal CSI-RS resources. The precoded / beamformed channel state information reference signal CSI-RS resources are used for downlink channel measurements and channel state information CSI calculations in the user equipment UE. Based on the downlink measurements of the precoded / beamformed channel state information reference signal CSI-RS, the user equipment UE calculates and reports a set of complex precoder coefficients for the configured antenna ports. It is assumed that each antenna port is associated with at least one beam, one delay, and one Doppler component. The user equipment UE only needs to determine the set of precoder coefficients for the configured antenna ports. Unlike Type II channel state information CSI reports, the user equipment UE does not need to calculate the beam and delay and Doppler components of the precoder matrix. Therefore, the complexity of the precoder calculations and the feedback overhead of the channel state information CSI report can be significantly reduced. Furthermore, while information on the angle, delay, and Doppler frequency of the channel's multipath components is available at high resolution (high definition) at the base station (or network node of the base station gNB), it is not quantized in the codebook and is not reported from the user equipment UE. Thus, the performance of the corresponding precoded downlink transmission using precoder coefficients reported from the user equipment UE will be significantly higher than the performance achieved with the current Release 15 or Release 16 Type II channel state information CSI reporting scheme.

[0049] The invention according to this embodiment also addresses the drawbacks described above. In detail, a method is proposed to significantly reduce feedback overhead in user equipment by omitting a codebook-based channel status information CSI report and uplink control information UCI or channel status information CSI based on a linear combination codebook.

[0050] In general, according to some non-limiting exemplary effects achieved by embodiments herein, angular information, delay information, and / or Doppler information are obtained from the user equipment UE at the base station gNB or at the network node via channel state information CSI reports or feedback. Based on downlink measurements of the channel state information reference signal CSI-RS, the user equipment UE calculates and reports a set of complex precoder coefficients for configured antenna ports, so that each antenna port is assumed to be associated with at least one beam and one delay and / or one Doppler component. Since the user equipment UE determines the set of precoder coefficients for configured antenna ports across multiple channel state information reference signal CSI-RS resources or a single channel state information reference signal CSI-RS resource in the angular-delay-Doppler domain, the feedback overhead of the channel state information CSI report can be significantly reduced compared to the conventional Release 15 and Release 16 Type II codebooks.

[0051] It should be noted that the term "precoding" is synonymous with "precoder." Therefore, throughout this disclosure, precoding and precoder are used interchangeably.

[0052] The term "beam" is used to describe spatially selective / directional transmission of an outgoing signal or reception of a received signal, achieved by precoding / filtering the signal at the antenna port of a device (user equipment UE or base station gNB) using a specific set of coefficients. The terms precoding, precoder, or filtering may refer to signal processing in the analog or digital domain. The set of coefficients used to spatially orient the transmit / receive in a given direction may differ for one direction and another. The term "Tx beam" represents spatially selective / directional transmission, and the term "Rx beam" represents spatially selective / directional reception. The set of coefficients used to precode / filter the transmit or receive is referred to as a "spatial filter." Since the spatial filter coefficients determine the direction in which the transmit / receive is spatially oriented, the term "spatial filter" is used interchangeably with the term "beam direction" in this document.

[0053] Exemplary embodiments of the present invention can be implemented in a wireless communication system or network, such as that depicted in Figure 1 or 2, which includes a transmitter or transceiver, such as a base station, and a communication device (receiver), such as a mobile terminal or stationary terminal or IoT device or user equipment UE, or a user, as described above in the background section of this disclosure.

[0054] Referring to Figure 3, we see a transmitter 200 such as a base station or base station gNB, and multiple communication devices 2021-202 such as user equipment UEs that are serviced by the base station 200. n A schematic diagram of a wireless communication system for communicating information between the base station 200 and the user equipment UE202 is shown. The base station 200 and the user equipment UE202 can communicate via a wireless communication link such as a radio link or channel 204. The base station 200 has one or more antennas ANT T The user equipment UE202 includes one or more antenna arrays, or an antenna array having multiple antenna elements, and a signal processor 200a.R , or an antenna array having multiple antennas, signal processors 202a1, 202a n , and transceivers 202b1, 202b n The base station 200 and each user equipment UE202 can operate in accordance with the teachings of the present invention as described herein.

[0055] According to embodiments of this specification, the user equipment UE is configured to generate a channel status information CSI report in a wireless communication system relating to a channel between the user equipment UE and a wireless base station or base station gNB, or similarly relating to a channel between a transmitter and a receiver. The channel may be a MIMO channel.

[0056] The transmitters and / or receivers described above may include one or more of the following: User equipment UE, or mobile terminal, or fixed terminal, or cellular IoT user equipment UE, or vehicle user equipment UE, or vehicle group leader GL user equipment UE, or IoT, or narrowband IoT, NB-IoT, device, or WiFi non-access point STation, non-AP_STA, e.g., 802.11ax or 802.11be, or ground vehicle, or air vehicle, or drone, or mobile base station, or roadside unit, or building, or other item or device with network connectivity that enables the item / device to communicate using a wireless communication network, e.g., sensor or actuator, or macrocell base station, or small cell base station, or central unit of a base station, or distributed unit of a base station, or relay, or remote radio head, or AMF (Access and Mobility Management Function), or SMF (Session Management Function), or core network entity, or mobile edge computing entity, or network slice in the context of new radio NR or 5G core, or any transmit / receive point (TRP) that enables the item or device to communicate using a wireless communication network, wherein the item or device is provided with network connectivity for communicating using a wireless communication network. The receiver may be a network node, a base station gNB, or a base station. Conversely, the transmitter can be considered a radio base station, a network node, or a base station gNB, while the receiver can be considered a user equipment UE.

[0057] The omission of Uplink Control Information (UCI) occurs when the uplink resources provided to the user equipment from the base station or network node for uplink transmission are insufficient to transmit the entire content of one or more Channel Status Information CSI reports. The Channel Status Information CSI payload of a Channel Status Information CSI report can be controlled by the user equipment UE by the number (many) of precoder coefficients reported. In the case of omission of Uplink Control Information UCI or Channel Status Information CSI, the user equipment UE can simply reduce the number of precoder coefficients to report for one or more Channel Status Information CSI reports based on the available uplink resources (e.g., available physical uplink shared channel PUSCH resources). However, such a reduction in the number of precoder coupling coefficients occupies additional user equipment UE resources because it requires recalculation of the precoder coefficients, which are all basis vectors (basis vectors) associated with the precoder vector or matrix for one or more Channel Status Information CSI reports. Such additional user equipment UE resources may not be available to the user equipment UE. Therefore, the uplink control information UCI omission scheme should not require recalculation of precoder vectors or matrices for one or more channel state information CSI reports.

[0058] The following describes, following detailed embodiments of this disclosure, the main steps performed by the user equipment UE and the steps performed by the network node, respectively. Figure 4 shows the main steps performed by the user equipment UE to generate (and transmit or report) a channel status information CSI report to a network node (base station) in a wireless communication network, according to embodiments of this specification. The steps performed by the user equipment UE can be defined as a codebook-based precoder structure. The steps performed by the user equipment UE include the following:

[0059] Step 401: The process of receiving channel status information CSI report configuration from the network node. As an example, a user device UE is provided with a channel status information CSI report configuration from a network node via a higher layer (such as RRC). The channel status information CSI report configuration indicates the number (numerous, number of) antenna ports or channel status information reference signal CSI-RS ports. An antenna port, or simply a port, refers to a channel status information reference signal CSI-RS port. Hereafter, antenna port, port, and channel status information reference signal CSI-RS port are used interchangeably. One or more antenna ports are associated with one or more reference signals. As an example, a user device UE (or receiver) is configured to receive radio signals over a MIMO channel. The radio signals have one or more reference signals, such as one or more channel status information reference signal CSI-RS signals associated with an antenna port.

[0060] Step 402: Based on the received channel status information CSI report configuration information, determine the number of precoder coefficients (number of precoder coefficients, number of precoder coefficients) for the rank index RI transmission layer of the precoder vector or matrix.

[0061] According to an exemplary embodiment, a receiver or user equipment UE determines a precoding vector or precoding matrix for each transmitting layer based on the received radio signal. The precoding vector or precoding matrix is ​​used by the transmitter (e.g., a network node) to achieve predefined characteristics for communication over a MIMO channel. The precoding vector or matrix for each transmitting layer is determined based on one or more received reference signals and is based on at least one first basis set and a number of precoder coefficients (an number of precoder coefficients) for joining selected basis vectors (basis vectors) from at least one first basis set. In one option, the precoding vector or matrix for each transmitting layer is determined based on the received reference signals and is based on a single (first) basis set and a number of precoder coefficients (an number of precoder coefficients) for joining selected basis vectors from that basis set. In another option, the precoding vector or matrix for each transmitting layer is determined based on a received reference signal, as well as a first and second basis set, and the number of precoder coefficients (annual of precoder coefficients, a number of precoder coefficients) used to combine the basis vectors selected from the first and second basis sets. In yet another option, the precoding vector or matrix for each transmitting layer is determined based on a received reference signal (one or more), as well as a first, second, and third basis set, and the number of precoder coefficients (annual of precoder coefficients, a number of precoder coefficients) used to combine the basis vectors selected from the first, second, and third basis sets.

[0062] Step 403: The precoder coefficients of the rank index RI layer are grouped into at least two coefficient subsets, each coefficient subset having one or more precoder coefficients.

[0063] According to an exemplary embodiment, each precoder coefficient is associated with at least two indices (l,p). The first index, l, is the layer index. The second index, p, is the port index. The rank index of the precoder coefficients for the RI layer of the precoder vector or matrix is ​​a subset of many non-overlapping coefficients A={A0,A1,…,A} in the channel state information CSI report. N-1 Grouped into}. Each coefficient subset A i It consists of precoder coefficients for rank index RI layers associated with a number of port indexes.

[0064] Step 404: Assign an order to multiple coefficient subsets, i.e., two or more coefficient subsets. Assign an order to one or more precoder coefficients within each subset.

[0065] Step 405: Divide the multiple coefficient subsets into two or more channel state information CSI groups that have associated priority levels. According to exemplary embodiments, multiple coefficient subsets are assigned an ordering to two or more coefficient subsets, and an ordering to one or more precoder coefficients within each subset. The multiple coefficient subsets are ordered with respect to ordering. The precoder coefficients within each subset are ordered with respect to ordering. The multiple coefficient subsets are divided or segmented into two or more channel status information CSI groups. Each channel status information CSI report and each channel status information CSI group are associated with a priority level. In some examples, the ordering of coefficient subsets within a channel status information CSI report is with respect to an increasing coefficient subset index.

[0066] Step 406: This step generates a channel status information CSI report comprising channel status information CSI part 1 and channel status information CSI part 2. Channel status information CSI part 1 has a fixed payload size and includes information indicating the payload size of channel status information CSI part 2. Channel status information CSI part 2 includes precoder coefficients for at least one group out of two or more channel status information CSI groups.

[0067] According to an exemplary embodiment, a channel status information CSI report comprises a selected precoding vector or matrix in the form of a precoding matrix index PMI and a rank identifier or rank index RI indicating the transmission rank of the rank index RI layer of the precoding vector or matrix. Each channel status information CSI report comprises two parts, namely channel status information CSI part 1 and channel status information CSI part 2. Channel status information CSI part 1 has a fixed payload size and comprises information indicating the payload size of channel status information CSI part 2. Channel status information CSI part 2 comprises at least amplitude and phase information of selected precoder coefficients for at least one group of two or more channel status information CSI groups of the channel status information CSI report.

[0068] Step 407: Send or report uplink control information (UCI) with one or more channel status information CSI reports via the uplink (UL) channel to the network node or gNB.

[0069] Therefore, the receiver (or user equipment UE) generates one or more channel state information CSI reports. The channel state information CSI report comprises at least one of two or more channel state information CSI groups, each having precoder coefficients for a precoded vector or matrix. The receiver reports feedback to the transmitter via the uplink channel in the form of one or more channel state information CSI reports. The feedback indicates the precoded vector or precoder matrix for each transmitting layer determined by the receiver (or user equipment UE).

[0070] According to another exemplary embodiment, a method is provided that is performed by a user device UE, the method comprising: The process of receiving a radio signal from a network node via a MIMO channel. The radio signal comprises one or more Channel State Information Reference Signal (CSI-RS) signals according to one or more Channel State Information Reference Signal (CSI-RS) resource configurations. The Channel State Information Reference Signal (CSI-RS) signals are provided across a number of configured frequency (and / or time) domain resources and across one or more antenna ports or one or more Channel State Information Reference Signal (CSI-RS) ports. A step of determining the number of precoder coefficients (multiple, number of) for the rank index RI transmission layer of the precoder vector or matrix, based on the channel state information CSI report configuration. A step of grouping the precoder coefficients of the rank index RI layer into at least two coefficient subsets. Each coefficient subset consists of one or more precoder coefficients. A process of assigning an order to multiple subsets of coefficients, and assigning an order to one or more precoder coefficients within each subset. A step of dividing the plurality of coefficient subsets into two or more channel state information CSI groups having associated priority levels. A process for generating a channel status information CSI report comprising channel status information CSI part 1 and channel status information CSI part 2. Channel status information CSI part 1 has a fixed payload size and includes information indicating the payload size of channel status information CSI part 2. Channel status information CSI part 2 includes precoder coefficients for at least one group out of two or more channel status information CSI groups. The process involves transmitting or reporting uplink control information (UCI), which includes one or more channel status information CSI reports, to network nodes via an uplink UL channel. The method comprises these steps.

[0071] In the following embodiments, it is assumed that each channel state information reference signal CSI-RS or antenna port resource is precoded or beamformed in the spatial, delay, and / or Doppler domains at the network node or base station. Therefore, the precoder used for channel state information CSI reporting at the user equipment UE is based on a codebook that takes advantage of the characteristics of angle, delay, and / or Doppler interaction between the uplink and downlink channels. However, the following embodiments with precoder formulations are also valid for non-precoded / non-beamformed antenna ports or channel state information reference signals CSI-RS at the network node or base station in the spatial, delay, and / or Doppler domains.

[0072] <Formulation of a precoder for channel status information CSI reports> In Option 1 below, the precoder is based on a single codebook or basis set and a number of precoders or combining coefficients used to combine selected basis vectors from the codebook or basis set. Each basis vector is associated with a full set of frequency and time domain resources of a channel state information reference signal CSI-RS or an antenna port, or is associated with an appropriate subset of the frequency and time domain resources of a channel state information reference signal CSI-RS or an antenna port used by a user equipment UE for channel state information CSI measurement. In some examples, each basis vector is associated with a full set of frequency and time domain resources of a channel state information reference signal CSI-RS or an antenna port. In such a case, the total number of basis vectors in the codebook or basis set defines the number of channel state information reference signals CSI-RS or antenna ports used by the user equipment UE for channel state information CSI measurement.

[0073] <Option 1: Precoder Structure Based on a Single Basis Set> According to an embodiment, a precoding vector for a transmission layer is P' basis vectors selected from a first basis set consisting of P basis vectors, where P' < P or P' ≤ P or P' = P, and a set of precoder coefficients for combining the selected basis vectors from the first basis set. In some examples, as described above, the resources are associated with the number P CSI-RS of channel state information reference signals CSI-RS or antenna ports. In some examples, as described above, the resources may be associated with the channel state information reference signals CSI-RS or antenna ports such that P > P CSI-RS and P CSI-RS is associated with the channel state information reference signals CSI-RS or antenna ports. In such a case, at least one basis vector of the first basis set may be associated with an appropriate subset of the resources of the channel state information reference signals CSI-RS or antenna ports. The precoding vector or matrix W l for the l-th transmission layer is defined by the following equation.

[0074]

number

[0075] Here, W 1,l This is a matrix consisting of P' basis vectors selected from the first basis set.

[0076] W 2,l This is the coefficient matrix. b l,p These are P×1 (1) basis vectors selected from the first basis set. b 1,l,p This is a P×1 (1) basis vector selected from the first basis set, and is related to the first polarization of the antenna port.

[0077] b 2,l,p This is a P×1 basis vector selected from the first basis set and is associated with the second polarization of the antenna port. c l,p These are complex precoder coefficients or coupling coefficients.

[0078] According to the embodiment, each basis vector in the first basis set is of size P × 1 and is defined by all zero vectors except for a single element which is 1. The first basis set is defined by a P × P identity matrix. The parameter P may be set or instructed to the user equipment from the network node via the higher layer. P can take any suitable value and is an integer.

[0079] According to one embodiment, the channel status information CSI report configuration (setting) includes a parameter P indicating the number of channel status information reference signals CSI-RS or antenna ports. CSI-RS It is configured to include the following: User equipment UE is P CSI-RSThe system is configured to perform channel measurements on each antenna port, determine the rank index RI transmission layer precoder vector or matrix, and display the rank index RI transmission layer precoder vector or matrix in the channel state information CSI report.

[0080] According to the embodiment, parameter P is the number of set channel state information reference signals CSI-RS or antenna ports P CSI-RS It can depend on this. In an exemplary embodiment, P = P CSI-RS Each basis vector from the first basis set is associated with a single antenna port. In an exemplary embodiment, P=P CSI-RS It is / 2. Each basis vector from the first basis set is associated with two antenna ports, and the two antenna ports are associated with two different polarizations. In some examples, P CSI-RS / The two antenna ports are associated with the first polarization, P CSI-RS The two antenna ports are associated with the second polarization.

[0081] The precoding vector or matrix for each transmitting layer is based on P' selected basis vectors from a first basis set. The selection is polarization-common if each vector in the first basis set is associated with resources at two antenna ports with different polarizations. The selection is polarization-independent if each vector in the first basis set is associated with resources at a single antenna port.

[0082] According to the embodiment, each precoding vector or matrix shown in the channel state information CSI report is (for example, channel state information reference signal CSI-RS or the number of antenna ports P) CSI-RS (Regarding this) It is defined across numerous frequency units / physical resource blocks (PRBs) or frequency domain subbands and spatial units.

[0083] According to the embodiment, a precoding vector or matrix W of l (lowercase L) = 0, ..., ν-1 lThe column is normalized to norm 1 (one). ν represents the overall rank of the transmitted precoding vector or precoding matrix.

[0084] Below, we consider a high-rank channel state information CSI report where ν≧1. Here, ν represents the rank, or simply the rank index RI value, and indicates the number of layers in the precoding matrix shown in the channel state information CSI report. The ν layers of the precoding matrix are represented by the layer index l=0,1,…,ν-1.

[0085] According to the embodiment, each precoder coefficient (amplitude and / or phase) of the precoding vector or matrix according to Option 1 of the precoder formulation is associated with a basis vector of the first basis set. Furthermore, each precoder coefficient is associated with two indices (l,p). The first index, l, is the layer index. The second index, p, is the port index, p=0,...,P'-1 or p=0,...,2P'-1. Note that if the precoder coefficient selection is polarization-independent, the range of the port index is defined as p=0,...,P'-1, whereas if the precoder coefficient selection is polarization-common, the range of the port index is defined as p=0,...,2P'-1. In some examples, the layer precoder coefficients are a coefficient matrix W of size P'×1 or 2P'×1. 2,l It is stacked on W 2,l The size of is P' × 1 when the selection of P' selected basis vectors in the first basis set is polarization-independent. 2,l The size is 2P' × 1 when the selection of P' pre-selected basis vectors in the first basis set is polarization-common.

[0086] Note that in some examples, the number of ports P' depends on the layer index and may differ for different layers of precoder vectors or matrices. In such cases, the parameter P' used above is P l It can be replaced with ′. P l′ indicates the number of selected basis vectors from the first basis set for layer index l. The number of basis vectors per layer can be set or selected by the user equipment UE via the higher layers (e.g., via the channel status information CSI report settings) and can be reported implicitly or explicitly (as part of the channel status information CSI report) to the base station or network node.

[0087] In an exemplary embodiment, if the antenna port or channel state information reference signal CSI-RS port is not precoded or beamforming, the first basis set is given by a 2D-DFT matrix instead of an identity matrix. Each selected vector b from the first basis set l,p This can be alternatively called a spatial beam or spatial beam vector.

[0088] In an exemplary embodiment, if the antenna port or channel state information reference signal CSI-RS port is not precoded or beamforming, a selected spatial beam vector from a first base set for each polarization of the antenna port or channel state information reference signal CSI-RS port, or simply a number of vectors b l,p It is either L / 2 or L.

[0089] In the following Option 2, the precoder is based on a number of basis vectors and a number of precoders or coupling coefficients for combining basis vectors from two basis sets. The basis vectors are selected from a first and second basis set. Each basis vector in the first basis set is associated with all frequency and time domain resources, or with an appropriate subset of the frequency and time domain resources of the channel state information reference signal CSI-RS or antenna ports. Each basis vector in the second basis set is associated with a number N3 of a frequency domain subband, a physical resource block (PRB), or a precoder unit.

[0090] <Option 2: Precoder Structure Based on Two Base Sets> According to an embodiment, the precoding vector for the transmission layer is based on P' base vectors, D' base vectors, and a set of precoder coefficients. The P' base vectors are P' base vectors selected from a first base set consisting of P base vectors, where P' < P or P' ≤ P or P' = P. The D' base vectors are D' base vectors selected from a second base set consisting of D base vectors, where D' < D or D' ≤ D or D' = D. The set of precoder coefficients is a set of precoder coefficients for combining the selected base vectors from the first and second base sets.

[0091] The precoding or precoder vector or precoding matrix for each transmission layer is based on P' selected base vectors from the first base set. The selection is polarization common if each vector of the second base set is associated with two antenna ports of different polarizations, while it is polarization independent if each vector of the first base set is associated with a single antenna port.

[0092] In an exemplary embodiment, for option 2 of the precoder formulation, the number P' of base vectors selected from the first base set may be different between the rank index RI layers of the precoder vector or matrix because it depends on the layer index. In such a case, the parameter P' used above is replaced by P l '. P l ' indicates the number of base vectors selected from the first base set for the layer index l. The number of base vectors per layer can be set for the user equipment UE via an upper layer (e.g., via a channel state information CSI report configuration), or can be selected by the user equipment UE and reported to the base station or network node implicitly or explicitly (as part of the channel state information CSI report).

[0093] According to one embodiment, each precoding vector or matrix shown in the channel state information CSI report is defined over the number of frequency units / physical resource blocks PRBs or the number of frequency domain sub-bands (e.g., with respect to the number N3 of sub-bands), and over the number of spatial units (e.g., with respect to the number of channel state information reference signals CSI-RSs, or with respect to the number of antenna ports P CSI-RS ).

[0094] According to an embodiment, each basis vector from the second basis set is defined by a discrete Fourier transform DFT vector or an inverse discrete Fourier transform IDFT vector of size N3×1. Each discrete Fourier transform DFT vector or inverse discrete Fourier transform IDFT vector defines a linear phase shift over N3 sub-bands or physical resource blocks PRBs or frequency units, and is thus associated with a delay value in the transform (delay or time) domain. The second basis set may be configured to include D basis vectors and is a subset of a basis set configured to include N3 discrete Fourier transform DFT-based or inverse discrete Fourier transform IDFT-based vectors of size N3×1. D < N3. N3 is the number of sub-bands, or physical resource blocks PRBs, or frequency domain units / components, used in the channel state information CSI report set by or reported by the user equipment UE. D and N3 can take any suitable values.

[0095] According to one embodiment, the channel state information CSI report configuration (setting) received by the user equipment UE from the network node may consist of indicating the parameter D (the size of the second basis set). The basis vectors of the second basis set are a subset of a basis set consisting of N3 basis vectors. D < N3. The D basis vectors of the second basis set are the N3×N3 discrete Fourier transform DFT-based or inverse discrete Fourier transform IDFT-based matrix [a0, a1, …, a N3-1is given by D discrete Fourier transform (DFT) vectors or inverse discrete Fourier transform (IDFT) vectors of

[0096] According to an embodiment, the precoding vector or matrix W l has columns that are normalized to norm 1 (one) for l = 0, …, ν−1, where ν denotes the overall rank of the transmit precoding vector or precoding matrix.

[0097] Hereinafter, high-rank channel state information (CSI) reports with ν≥1 are considered, where ν denotes the rank, or simply the rank index (RI) value, and indicates the number of layers of the precoding matrix indicated in the channel state information (CSI) report. The ν layers of the precoding matrix are indicated by layer index l = 0, 1, …, ν−1.

[0098] According to an embodiment, the precoding vector or precoding matrix for each transmit layer of the transmit layer is based on D′ (D′≤D, or D′<D) or D basis vectors selected from a second basis set, P′ (P′≤P, or P′<P) or P basis vectors selected from a first basis set, and a set of precoders or coupling coefficients for combining the vectors selected from the first and second basis sets. The precoding vector or precoding matrix W l is defined over the number (N3) (a number) of frequency units / physical resource blocks (PRBs) or frequency domain sub-bands and the space unit (P) of the l-th (lowercase el) transmission layer. In some examples, the precoding vector or precoding matrix W l for the l-th (lowercase el) transmit layer can be defined as follows.

[0099]

Equation

[0100] Here, W 1,lThis is a matrix consisting of P' basis vectors selected from the first basis set.

[0101] W 2,l This is the coefficient matrix. W f,l H This is a matrix consisting of D', D, or less than D basis vectors from the second basis set.

[0102] b l,p This is a P×1 vector from the first basis set. a l,p,d is an N3×1 basis vector from the second basis set. c l,p,d is a complex precoder coefficient or combining coefficient.

[0103] According to the embodiment, each precoder coefficient (amplitude and / or phase) of the precoding vector or matrix according to Option 2 of the precoder formulation is associated with the basis vectors of the first basis set and the basis vectors of the second basis set. Each precoder coefficient is associated with three indices (l, p, d). The first index l is the layer index. The second index p is the port index, p=0,...,P'-1 or p=0,...,2P'-1. The third index d is the delay index, d=0,...,D'-1. In some examples, the layer precoder coefficients are associated with a coefficient matrix W of size P'×D' or 2P'×D'. 2,l It is stacked on W 2,l The size of W is P' × D', where the selection of P' basis vectors from the first basis set is polarization-independent. 2,l The size is 2P' × D' if the selection of P' basis vectors from the first basis set is polarization common.

[0104] In this exemplary embodiment, D' = D. The coefficient matrix W 2,lThe second dimension is defined by the total number of basis vectors in the second basis set. Each column of the coefficient matrix is associated with a single basis vector from the second basis set.

[0105] In an exemplary embodiment, P′ = P. The coefficient matrix W 2,l has a first dimension of P or 2P. Each row of the coefficient matrix is associated with a single basis vector from the first basis set.

[0106] In an exemplary embodiment, when an antenna port or a channel state information reference signal CSI-RS port is not precoded or beamformed, the first basis set is given by a two-dimensional discrete Fourier transform 2D-DFT matrix instead of an identity matrix. Each selected vector b l,p from the first basis set can alternatively be called a spatial beam or a spatial beam vector.

[0107] In an exemplary embodiment, when an antenna port or a channel state information reference signal CSI-RS is not precoded or beamformed, the number of selected vectors b l,p from the first basis set for each polarization is given by L / 2 or L.

[0108] <Option 3: Precoder Structure Based on Three Basis Sets> According to an embodiment, the precoding vector of the transmission layer is based on P′ selected basis vectors (where P′ < P or P′ ≦ P or P′ = P) from a first basis set consisting of P basis vectors, D′ selected basis vectors (where D′ < D or D′ ≦ D or D′ = D) from a second basis set consisting of D basis vectors, E′ selected basis vectors (where E′ < E or E′ ≦ E or E′ = E) from a third basis set consisting of E basis vectors, and a set of precoder coefficients for combining the selected basis vectors from the first, second, and third basis sets.

[0109] The precoding or precoder vector or precoding matrix for each transmitting layer is based on P' basis vectors selected from a first basis set. The selection is polarization-common if each selected vector from the first basis set is associated with two antenna ports with different polarizations. The selection is polarization-independent if each selected vector from the first basis set is associated with a single antenna port and polarization.

[0110] In an exemplary embodiment, the number of basis vectors P' selected from the first basis set depends on the layer index and can differ between layers with different rank indices of precoder vectors or matrices. In such a case, the parameter P' used above is P l It can be replaced with ′. P l ′ indicates the number of selected basis vectors from the first basis set for layer index l. The number of basis vectors per layer may be configured in the user equipment UE via higher layers (e.g., via the channel status information CSI report configuration) or selected by the user equipment UE and may be reported implicitly or explicitly (as part of the channel status information CSI report) to the base station or network node.

[0111] According to the embodiment, each precoding vector or matrix shown in the channel state information CSI report is a number of frequency units / physical resource blocks PRB or frequency domain subbands (e.g., with respect to a number of subbands N3) and spatial units (e.g., a number of channel state information reference signals CSI-RS or antenna port P CSI-RS It is defined over the course of (regarding).

[0112] According to one embodiment, each basis vector from the second basis set is defined by a discrete Fourier transform (DFT) vector or an inverse discrete Fourier transform (IDFT) vector of size N3×1. Since each DFT vector or IDFT vector defines a linear phase shift over N3 sub-bands or physical resource blocks (PRBs) or frequency units, it is thus associated with a delay value in the transform (delay or time) domain. The second basis set may be configured with D basis vectors and is a subset of a basis set comprising N3 DFT-based or IDFT-based vectors of size N3×1 (e.g., an oversampled DFT-based matrix). D < N3. N3 is the number of sub-bands or PRBs or frequency domain units / components used in a channel state information (CSI) report configured for or reported by a user equipment (UE). D and N3 can take any suitable values.

[0113] According to an embodiment, a CSI report configuration received by a UE from a network node may include indicating a parameter D (the size of the second basis set). The basis vectors of the second basis set are a subset of a basis set consisting of N3 or N3Q3 or N3Q3−1 basis vectors. D < N3. Q3 indicates an oversampling factor. In some examples, the D basis vectors of the second basis set are an N3×N3 DFT-based or IDFT-based or rotated N3×N3 DFT-based or IDFT-based matrix [a0, a1, …, a N3-1It is given by D discrete Fourier transform (DFT) vectors or inverse discrete Fourier transform (IDFT) vectors of []. In some examples, the D basis vectors of the second basis set are the D discrete Fourier transform (DFT) vectors or inverse discrete Fourier transform (IDFT) vectors of an oversampled N3×N3Q3 or N3×N3Q3 - 1 discrete Fourier transform (DFT)-based or inverse discrete Fourier transform (IDFT)-based matrix.

[0114] According to an embodiment, each basis vector from the third basis set is defined by a discrete Fourier transform (DFT) vector or inverse discrete Fourier transform (IDFT) vector of size N4×1. Each discrete Fourier transform (DFT) vector or inverse discrete Fourier transform (IDFT) vector defines a linear phase shift over N4 time instants and is thus associated with Doppler values in the transformed time domain. The third basis set may be configured with E basis vectors and is a subset of a basis set configured with N4 or N4Q4 or N4Q4 - 1 discrete Fourier transform (DFT)-based or inverse discrete Fourier transform (IDFT)-based vectors of size N4×1. E < N4 or E = N4. N4 is the number of time instant / Doppler components set in or reported by the user equipment (UE) for use in a channel state information (CSI) report. Q4 is the oversampling factor E. N4 can take any suitable value.

[0115] According to one embodiment, the channel state information (CSI) report configuration received by the user equipment (UE) from the network node may include indicating the parameter E (the size of the third basis set). The basis vectors of the third basis set are a subset of a basis set consisting of N4 basis vectors. E < N4. The E basis vectors of the third basis set are of a discrete Fourier transform (DFT)-based or inverse discrete Fourier transform (IDFT)-based or rotated discrete Fourier transform (DFT)-based or inverse discrete Fourier transform (IDFT)-based matrix of N4×N4 [d0, d1, …, d N4-1is given by E discrete Fourier transform (DFT) vectors or inverse discrete Fourier transform (IDFT) vectors. In some examples, the E basis vectors of the third basis set are given by E discrete Fourier transform (DFT) or inverse discrete Fourier transform (IDFT) vectors of an oversampled N4×N4Q4 or N4×N4Q4−1 DFT vector or inverse discrete Fourier transform (IDFT)-based matrix.

[0116] According to an embodiment, the columns of the precoding vector or matrix W l are normalized to norm 1 (one) for l = 0, …, ν−1. Here, ν indicates the overall rank of the transmission precoding vector or precoding matrix.

[0117] Hereinafter, consider a high-rank channel state information (CSI) report with ν≥1. Here, ν indicates the rank or simply the rank index (RI) value, and also indicates the number of layers of the precoding matrix indicated in the channel state information (CSI) report. The ν layers of the precoding matrix are indicated by layer index l = 0, 1, …, ν−1.

[0118] According to an embodiment, the precoding vector or precoding matrix for each transmission layer is based on D′ (D′≤D, or D′<D) or D basis vectors selected from the second basis set, and / or E′ (E′≤E, or E′<E) or E basis vectors selected from the third basis set, and P′ (P′≤P, or P′<P) or P basis vectors selected from the first basis set, and a set of precoders or combining coefficients for combining selected vectors from the first, second, and / or third basis sets. The precoding vector or precoding matrix W lis defined over the number of frequency units / physical resource blocks PRBs or frequency domain sub-bands (N3) for the l-th transmission layer, and / or over the number of time instants (N4) and spatial units (P). In some examples, the precoding vector or precoding matrix W for the l-th transmission layer and the t-th time instant (moment, instance) l,t can be defined by the following equation.

[0119]

Number

[0120] Here, b l,p is a P×1 vector from the first basis set. a l,p,d is an N3×1 basis vector from the second basis set.

[0121]

Number

[0122] is the t-th component / entry (t = 0, 1, …, N4 - 1) of the selected n-th 4,l,p,d basis vector / time domain component from the third basis set. And c l,p,d,n is a complex precoder coefficient or coupling coefficient.

[0123] In an exemplary embodiment, the selected number of delays D′ or D is equal to the number of Doppler components E′ or E. According to an embodiment, each precoder coefficient (amplitude and / or phase) of a precoding vector or matrix according to option 3 of the precoder formulation is associated with a basis vector of a first basis set, a basis vector of a second basis set, and a basis vector of a third basis set. Each precoder coefficient is associated with four indices (l, p, d, n). The first index l is a layer index. The second index p is a port index. p = 0, …, P′−1 or p = 0, …, 2P′−1. The third index d is a delay index. d = 0, …, D′−1. The fourth index n is a Doppler component index. n = 0, …, E′−1.

[0124] In an exemplary embodiment, for D′ selected delays and E′ Doppler components, the number of precoder coefficients for each spatial beam or selected channel state information reference signal CSI-RS or antenna port is either D′ or E′. Each precoder coefficient is associated with a pair (d, n) of delay and Doppler indices. Hereinafter, for simplicity, the precoder coefficient c l,p,d,n is denoted as c l,p,d where d indicates a delay and / or Doppler index or a pair of delay and Doppler indices.

[0125] In the following embodiments, it is assumed that the number of delay and Doppler components for each beamforming or non-beamforming channel state information reference signal CSI-RS or antenna port is given by D′.

[0126] In some examples, the precoder coefficients of a layer are stacked in a coefficient matrix W 2,l of size P′×D′ or 2P′×D′. The size of W 2,l is P′×D′ when the selection of P′ basis vectors from the first basis set is polarization-independent. The size of W 2,l is 2P′×D′ when the selection of P′ basis vectors from the first basis set is polarization-common.

[0127] In the exemplary embodiment, D' = D. Next, the coefficient matrix W 2,l The second dimension is defined by the total number of basis vectors in the second basis set. Each column of the coefficient matrix is ​​associated with a single basis vector from the second basis set.

[0128] In this exemplary embodiment, P' = P. The coefficient matrix W 2,l The first dimension of the matrix is ​​P or 2P. Each row of the coefficient matrix is ​​associated with a single basis vector from the first basis set.

[0129] In exemplary embodiments, for options 1, 2, and 3 of the precoder formulation, the number of basis vectors P' selected from the first basis set depends on the layer index, and therefore may differ between layers RI with different rank indices of precoder vectors or matrices. In such cases, P l ′ represents the number of basis vectors in the i-th layer. The number of basis vectors per layer can be set via the upper layers (for example, via the channel state information CSI report configuration), or it can be selected by the user equipment UE and reported implicitly or explicitly to the base station or network node.

[0130] <Number of subbands:> According to the embodiment, the user device UE has upper layer configuration parameters,

number

[0131] According to one embodiment, the user device UE has a parameter Q and the number of channel quality index CQI subbands N. CQI Based on

number

[0132] <Omission of uplink control information UCI> Depending on the embodiment, the uplink resource or uplink control information (UCI) may include one or more reduced-size channel status information CSI reports. The uplink control information UCI may comprise uplink control information UCI or channel status information CSI part 1 and uplink control information UCI or channel status information CSI part 2. In some examples, uplink control information UCI or channel status information CSI part 1 may include an indication of the number of precoder (amplitude and / or phase) coefficients per layer or across all layers of the precoder vector or matrix in one or more channel status information CSI reports. In some examples, uplink control information UCI or channel status information CSI part 1 may include a rank indication or rank index (RI) of one or more channel status information CSI reports, and may also indicate the number of layers of the precoder vector or matrix in the channel status information CSI reports.

[0133] According to the embodiment, the user equipment UE is configured to receive an uplink resource allocation from the base station for uplink transmission of one or more channel status information CSI reports. The user equipment UE may determine that the size of the resource allocation is not sufficient to transmit the entire content of the channel status information CSI report. In such a case, the user equipment UE may determine one or more reduced-size channel status information CSI reports that fit within the uplink resource allocation by performing a channel status information CSI or uplink control information UCI omission procedure. One or more reduced-size channel status information CSI reports may be transmitted to the base station over the uplink channel.

[0134] In one embodiment, the channel state information CSI omission procedure is based on removing some of the amplitude and phase or coupling coefficients of the precoder of one or more channel state information CSI reports. In other words, the user equipment UE is configured to omit parts of one or more channel state information CSI reports, thereby providing one or more reduced-size channel state information CSI reports for transmission over the uplink channel to the base station.

[0135] According to the embodiment, multiple coefficient subsets having coupling coefficients or precoder coefficients are segmented into two or more channel state information CSI groups for each channel state information CSI report in order to omit channel state information CSI. A certain ordering is applied to the coefficient subsets and precoder coefficients. The coefficient subsets are segmented or divided into two or more channel state information CSI groups. Furthermore, each channel state information CSI report and each channel state information CSI group may be associated with a priority level.

[0136] In one embodiment, the procedure for omitting channel state information CSI or uplink control information UCI is based on dropping one or more groups of channel state information CSI, and therefore the relevant phase and amplitude coefficients of the precoder vector or matrix in the associated channel state information CSI report, according to a priority rule. Thus, in the case of omitting channel state information CSI or uplink control information UCI, some of the amplitude and / or phase coefficients of the precoder vector or matrix shown in the channel state information CSI report are omitted.

[0137] According to the embodiment, the user equipment UE may drop channel status information CSI groups if lower-priority uplink control information UCI or channel status information CSIs are omitted, until the payload size of the channel status information CSI report fits the resource allocation from the base station. If a channel status information CSI group of a particular priority level is omitted, the user equipment UE may omit all channel status information CSI content of that priority level.

[0138] <Report on non-zero precoder coefficients> To reduce the signaling overhead for reporting precoder coefficients, only a subset or appropriate subset of precoder vectors or matrices of size P'×1-, 2P'×1-, P'×D'-, or 2P×D'- may be reported and therefore shown in the channel state information CSI report. The remaining precoder coefficients are assumed to be zero (or set to zero) and are therefore not reported. K to be reported NZ A subset of precoder coefficients consisting of n non-zero coefficients is referred to below as the non-zero coefficients. Furthermore, the channel state information CSI report may include indicators to show the positions of non-zero coefficients in the coefficient matrix. In some examples, such indicators are given by bitmaps of size P'×1 or 2P'×1 or P'×D' or 2P'×D'. Each bit corresponds to the coefficient matrix W 2,lIt is associated with the precoder coefficients within the bitmap. When a bit of the bitmap is set to "1", the associated precoder coefficients are reported. When a bit of the bitmap is set to "0", the associated precoder coefficients are not reported and are treated as zero.

[0139] The following embodiments describe a port selection codebook assuming a precoded or beamformed channel state information reference signal CSI-RS or antenna port. Therefore, the number of selected ports is denoted by P′ or 2P′. However, the following embodiments are also valid for a linear combination codebook assuming a non-precoded or non-beamformed channel state information reference signal CSI-RS or antenna port. In this case, the number of selected ports (P′) or (2P′) is replaced by the number of spatial beams (L) or (2L).

[0140] For non-precoded or non-beamforming antenna ports or channel state information reference signals (CSI-RS), in order to reduce the signaling overhead for reporting precoder coefficients, only a subset or appropriate subset of L×1- or 2L×1 or L×D′- or 2L×D′- size precoder vectors or matrices may be reported and therefore shown in the channel state information CSI report. The remaining precoder coefficients are assumed to be zero (or set to zero) and are therefore not reported. NZ A subset of precoder coefficients consisting of n non-zero coefficients is referred to below as the non-zero coefficients. Furthermore, the channel state information CSI report may include an indicator to show the position of the non-zero coefficients in the coefficient matrix. Such an indicator is given by a bitmap of size L×1 or 2L×1 or L×D′ or 2L×D′. Each bit corresponds to the coefficient matrix W 2,lIt is associated with the precoder coefficients within the bitmap. When a bit of the bitmap is set to "1", the associated precoder coefficients are reported. When a bit of the bitmap is set to "0", the associated precoder coefficients are not reported and are treated as zero.

[0141] The precoder coefficients for each layer are normalized so that the amplitude and phase of the strongest precoder coefficient are equal to 1 and 0, respectively. In this case, since the amplitude and phase are given as 1 and 0, respectively, there is no need to report the strongest precoder coefficient. The user device UE includes the row index and column index related to the strongest coefficient, or the coefficient matrix W related to the strongest coefficient, in the channel state information CSI report. 2,l The row index or column index can be shown.

[0142] According to the embodiment, the user device UE includes a coefficient matrix W associated with the strongest coefficient for each layer in the channel state information CSI report. 2,l It may be configured to show the row index and column index, or only the row index, or only the column index.

[0143] Therefore, the number of non-zero coefficients per layer reported in the channel state information CSI report is K NZ,l It is given by -1. The total number of non-zero coefficients reported in the channel state information CSI report across all layers is Σ l K NZ,l - Given by rank index RI

[0144] According to the embodiment, for option 1 of the precoder formulation, the channel state information CSI report is one of the P' or 2P' precoder coefficients per layer, K NZ,l or K NZ,l This consists of reporting -1 non-zero precoder coefficients. Here, K NZ,l This indicates the number of non-zero precoder coefficients for each layer. The total number of non-zero precoder coefficients across all layers is K NZ =Σ l K NZ,l It is given by.

[0145] According to the embodiment, for option 2 of the precoder formulation, the channel state information CSI report has K of the P'D' or 2P'D' precoder coefficients per layer. NZ,l or K NZ,l - This consists of reporting a report of one non-zero precoder coefficient. Here K NZ,l This represents the number of non-zero precoder coefficients in each layer. The total number of non-zero precoder coefficients across all layers is K NZ =Σ l K NZ,l It is given by.

[0146] According to the embodiment, for option 3 of the precoder formulation, the channel state information CSI report has K of the P'D' or 2P'D' precoder coefficients per layer. NZ,l or K NZ,l - This consists of reporting one non-zero precoder coefficient. K NZ,l This indicates the number of non-zero precoder coefficients for each layer. The total number of non-zero precoder coefficients across all layers is K NZ =Σ l K NZ,l It is given by.

[0147] According to the embodiment, (if present in the channel state information CSI report) the bits in the bitmap are similarly ordered by a subset of coefficients and the precoder coefficients within the subset of coefficients.

[0148] In the current new wireless NR specification, the maximum number of supported channel state information reference signal CSI-RS ports is 32. According to the precoder formulations of Option 1 and Option 2 described above, the size of the precoder coefficient matrix for each layer is P'×1 or 2P'×1 and P'×D' or 2P'×D', respectively. Since the value of P' is typically higher than the value of D' (if present) and rank index RI, the precoder coefficients associated with a subset of P' or 2P' port indices (rows) of all D' delays and / or Doppler indices (if present) may be sufficient to achieve satisfactory performance in the case of omitting channel state information CSI. Therefore, P' or 2P' or P l Precoder coefficients associated with a subset of port indexes (rows) or an appropriate subset are grouped into multiple coefficient subsets. If channel state information (CSI) or uplink control information (UCI) is omitted, some or all of the precoder coefficients associated with a coefficient subset(s) may be dropped or discarded sequentially starting from the last coefficient subset N-1. The ordering of precoder coefficient subsets, as well as the precoder coefficients of each coefficient subset, significantly impacts precoder performance, as dropping some or all coefficients associated with a layer(s) may result in performance loss. Therefore, a specific ordering scheme for the coefficient subsets, as well as the precoder coefficients of each coefficient subset, is necessary to mitigate performance loss in the event of omission. Below, several schemes for ordering coefficient subsets and precoder coefficients are described in detail.

[0149] <Grouping scheme for precoder coefficients in channel status information CSI report (Precoder formulation option 1)> According to the embodiment, each precoder coefficient in the coefficient subset is associated with at least two indices (l,p). The first index, l=0,…,RI-1, is the layer index. The second index, p∈U, is the port index. U={0,…,P′-1} or U={0,…,2P′-1} is the set of port indices. If the selection of precoding coefficients is polarization-independent, the set U consists of P′ port indices and is defined as U={0,…,P′-1}. Here, the precoder coefficient associated with port index p∈U is associated with the first or second polarization of the antenna port. If the selection of precoding coefficients is polarization-common, the set U consists of 2P′ port indices and is defined as U={0,…,2P′-1}. Here, the precoder coefficient associated with port index p∈{0,…,P′-1} is associated with the first polarization of the antenna port. The precoder coefficient associated with port index p+P' is associated with the second polarization of the same antenna port. Therefore, the precoder coefficient associated with port index {0, ..., P'-1} is associated with the first polarization of the antenna port. The precoder coefficient associated with port index {P', ..., 2P'-1} is associated with the second polarization of the antenna port.

[0150] According to Embodiment S1, the precoder coefficients of the rank index RI layer of the precoding vector or matrix are a number of non-overlapping coefficient subsets A={A0,A1,…,A} in the channel state information CSI report. N-1 They are grouped into}. Each coefficient subset A i It is comprised of precoder coefficients in the rank index RI layer associated with a number of port indices. The precoder coefficients of the i-th layer of the coefficient subset are associated with one subset of consecutive port indices from U, or with two subsets of consecutive port indices from U.

[0151] According to the embodiment, the first coefficient subset may include precoder coefficients related to the two polarizations of the antenna port. According to the embodiment, each coefficient subset may be configured to include precoder coefficients related to the two polarizations of the antenna port.

[0152] According to the embodiment, the i-th coefficient subset comprises a subset of the precoder coefficients of the rank index RI layer. The precoder coefficients of the l-th layer are B i,l Port Index (or B i,l (Associated with port index less than B) i,l A port index is defined by a subset of consecutive port indices starting from U, or B i,l The port index is defined by two subsets of the contiguous port index starting from U.

[0153] In some examples, the port index B for each coefficient subset i,l The number of elements may be the same for all rank index RI layers. In some examples, port index B i,l The number of coefficients is the total number of coefficients A i They are identical to port index B. In some examples, port index B i,l The number of coefficients is subset A i They are not identical across the spectrum.

[0154] In some examples, the coefficient subset {A0, A1, ..., A N-1 The} are ordered in the Channel Status Information CSI report with respect to the increasing subset index. In an exemplary embodiment, there are 2P' precoder coefficients. P' precoder coefficients are associated with the first polarization of the antenna port. P' precoder coefficients are associated with the second polarization of the antenna port. The rank index RI layer precoder coefficients are grouped into two non-overlapping coefficient subsets (N=2) in the channel state information CSI report. The first coefficient subset A0 comprises the precoder coefficients of all rank index RI layer indices associated with the first P' / 2 port indices (p=0,...,P' / 2-1) of the first polarization of the antenna port, and the precoder coefficients of all rank index RI layer indices associated with the first P' / 2 port indices (p=P'+0,...,P'+P' / 2-1) of the second polarization of the antenna port. The second coefficient subset A1 comprises the precoder coefficients for all rank index RI layer indices associated with the remaining P' / 2 port indices of the first polarization of the antenna port (p=P' / 2,…,P'-1), and the precoder coefficients for all rank index RI layer indices associated with the remaining P' / 2 port indices of the second polarization of the antenna port (p=P'+P' / 2,…,2P'-1). Note that in some examples, P'=P. In some examples, the precoder selection is common to the polarization, as shown in Figure 5. The rank index RI=2 and P'=8. The set of port indices U is defined as U={0,…,15}. The port indices selected in layer 0 and layer 1 are {0,1,2,3,4,5,9,10,11,13,14,15} and {0,4,5,8,9,11,13,15}, respectively. Each coefficient subset consists of precoder coefficients associated with four port indices for each polarization of both layers. The first coefficient subset A0 consists of precoder coefficients associated with the port indices {0,1,2,3,9,10,11} and {0,8,9,11} of layer 0 and layer 1, respectively. The second coefficient subset A1 consists of precoder coefficients associated with the port indices {4,5,13,14,15} and {4,5,13,15} of layer 0 and layer 1, respectively.

[0155] <Grouping of precoder coefficients based on the global port index> According to one embodiment, each precoder coefficient in the coefficient subset is associated with two indices (l,p). The first index l = 0, ..., RI-1 is a sheath index. The second index p ∈ U' is a global port index. U' = {0, ..., P-1} or U' = {0, ..., 2P-1} is the set of global port indices, where P represents the number of vectors in the first basis set.

[0156] Assume there exists a mapping between a global port index p ∈ U' and a local port index p ∈ U. If the selection of precoding coefficients is polarization-independent, the set U' consists of P port indices and is defined as U' = {0, ..., P-1}. Here, the precoding coefficients associated with port index p ∈ U' are associated with either the first or second polarization of the antenna port. If the selection of precoding coefficients is polarization-common, the set U' consists of 2P global port indices and is defined as U' = {0, ..., 2P-1}. Here, the precoding coefficients associated with global port index p ∈ {0, ..., P-1} are associated with the first polarization of the antenna port. The precoding coefficients associated with global port index p + P are associated with the second polarization of the same antenna port. (See Figure 6).

[0157] According to the embodiment, the precoder coefficients are grouped into multiple coefficient subsets based on (global) 2P port indices. In one exemplary embodiment, there are 2P' or P' precoder coefficients. P' precoder coefficients are associated with the first polarization of the antenna port. P' precoder coefficients are associated with the second polarization of the antenna port, or P' precoder coefficients are associated with the first and / or second polarization of the antenna port. The rank index RI layer precoder coefficients are grouped into two non-overlapping coefficient subsets (N=2) in the channel state information CSI report. The first coefficient subset A0 comprises the precoder coefficients of all rank index RI layer indices associated with the first P / 2 global port indices of the first polarization (0,...,P / 2-1) of the antenna port, and the precoder coefficients of all rank index RI layer indices associated with the first P / 2 global port indices of the second polarization (P+0,...,P+P / 2-1) of the antenna port. The second coefficient subset A1 comprises precoder coefficients for all rank index RI layer indices related to the remaining P / 2 global port indices for the first polarization (P / 2, ..., P-1) of the antenna port, and precoder coefficients for all rank index RI layer indices related to the remaining P / 2 global port indices for the second polarization (P+P / 2, ..., 2P-1) of the antenna port.

[0158] In some examples, the precoder selection is polarization-common, as shown in Figure 7. The rank index RI=2, P=8, and P′=6, where U′={0,…,15} and U={0,…,11}. The selected global port indices for layer 0 and layer 1 are {0,1,2,7,8,9,11,12,15} and {0,2,4,6,7,9,13,15}, respectively. According to indexing based on P′, i.e., indexing based on U={0,…,11}, the selected port indices for layer 0 and layer 1 are {0,1,2,5,6,7,8,9,11} and {0,2,3,4,5,7,10,11}, respectively. The first coefficient subset consists of precoding coefficients associated with the port indices {0,1,2,8,9,11} and {0,2,9} for layer 0 and layer 1, respectively. The second coefficient subset consists of precoding coefficients associated with the port indices {7,12,13} and {4,6,7,13,15} of the 0th and 1st layers, respectively.

[0159] In an exemplary embodiment, each coefficient subset is, layer by layer

number

number

number

[0160] In some examples, the rank index RI = 2. The number of precoder coefficients for the 0th and 1st layers are P0′ = 13 and P1′ = 9 respectively. When N = 2, the first coefficient subset A0 consists of the first 7 and first 5 precoder coefficients of the 0th and 1st layers respectively. The second coefficient subset A1 consists of the remaining 6 and 4 precoder coefficients of the 0th and 1st layers respectively.

[0161] In an exemplary embodiment, the number of precoder coefficients per layer depends on the maximum number of selected precoder coefficients across all layers, i.e., P m = max(P l ′), ∀l (lowercase l). Here, P l ′ represents the number of selected precoder coefficients for each polarization of the antenna port. In some examples, the maximum number of precoder coefficients per layer for each coefficient subset is

Number

[0162] In some examples, the number of coefficient subsets N is equal to 2. The first coefficient subset consists of <00​​​​​​​​​​​​​​​​​​​= 12. Each coefficient subset consists of the six precoder coefficients from the 0th and 1st layers. Since the 1st layer is associated with eight precoder coefficients, coefficient subset A0 consists of the first six precoder coefficients. Coefficient subset A1 consists of the remaining two precoder coefficients. The precoder coefficients are ordered with respect to the increasing port index.

[0164] In some examples, the rank index RI = 2. The number of precoder coefficients in the 0th and 1st layers are P0' = 13 and P1' = 9, respectively. Here P m = 13. When N=2, the first coefficient subset A0 consists of the first 7 precoder coefficients of the 0th and 1st layers. The second coefficient subset A1 consists of the remaining 6 precoder coefficients of the 0th and 1st layers and 2 precoder coefficients, respectively.

[0165] In some examples, the rank index RI=2. The number of port indices for each layer 0 and 1 is P0'=13 and P1'=4, respectively. Here P m = 13. When N=2, the first coefficient subset A0 consists of the first 7 precoder coefficients of layer 0 and the first 4 precoder coefficients of layer 1. The second coefficient subset A1 consists of the remaining 6 precoder coefficients of layer 0.

[0166] <Further grouping and ordering of coefficient subsets> According to the sub-embodiment indicated as S1-1, each coefficient subset A i The precoder coefficients are a subset of many coefficients A in the channel state information CSI report. i ={A i,1 ,…,A i,T It can be further grouped into}. Each coefficient subset A i,j It comprises one or two subsets of continuous port indices from U or U' associated with the first and second polarizations of the antenna port, a single layer index, and precoder coefficients associated with it. Coefficient subset A i,jThese are ordered with respect to the increasing layer index.

[0167] According to the sub-embodiment shown as S1-2, each coefficient subset A i The precoder coefficients are a subset of many coefficients A in the channel state information CSI report. i ={A i,1 ,…,A i,T It can be further grouped into}. Each coefficient subset A i,j This is a subset of coefficients A for single port index and single polarization. i It consists of precoder coefficients associated with all layer indices associated with it. Coefficient subset A i,j These are ordered with respect to the increasing port index.

[0168] According to the sub-embodiments indicated as S1-3, each coefficient subset A i The precoder coefficients are a subset of many coefficients A in the channel state information CSI report. i ={A i,1 ,…,A i,T They can be grouped into}. Each coefficient subset A i,j This is a subset of coefficients A for single port index and single polarization. i It consists of precoder coefficients associated with all layer indices associated with it. Coefficient subset A i,j These are ordered with respect to increasing polarization or polarization index.

[0169] <Ordering of precoder coefficients in a coefficient subset> The following exemplary embodiment, according to sub-embodiment S1-1, applies coefficient subset A i,j We propose an ordering scheme for precoder coefficients in this context.

[0170] According to the embodiment, each coefficient subset A i,j The precoder coefficients are ordered with respect to the increasing port index. According to the embodiment, each coefficient subset A i,jThe precoder coefficients are ordered with respect to the increasing port index. The precoder coefficients associated with the same port index are ordered with respect to the increasing polarization or polarization index.

[0171] In some examples, the number of coefficient subsets is two. For the two coefficient subsets A0 and A1, each subset is associated with P' / 2 port indices of the first and second polarizations of the antenna ports. The ordering of the precoder coefficients of coefficient subset A0 for the case of rank index RI = 2 is given as follows.

[0172]

Number

[0173] According to an embodiment, the precoder coefficients of each coefficient subset A i,j are ordered with respect to the increasing polarization or polarization index. The precoder coefficients associated with the same polarization or polarization index are ordered with respect to the increasing port index.

[0174] In some examples, the number of coefficient subsets is two. For the two coefficient subsets A0 and A1, each subset is associated with P' / 2 port indices of the first and second polarizations of the antenna ports. The ordering of the precoder coefficients of coefficient subset A0 for the case of rank index RI = 2 is given as follows.

[0175]

Number

[0176] The following embodiment proposes an ordering scheme for the precoder coefficients of coefficient subset A i,j according to sub-embodiment S1-2. According to an embodiment, each coefficient subset A i,jThe precoder coefficients are ordered with respect to the increasing layer index. Precoder coefficients associated with the same layer index are ordered with respect to the increasing polarization or polarization index. In some examples, there are two coefficient subsets. For the two coefficient subsets A0 and A1, each subset is associated with P' / 2 port indices for the first and second polarizations of the antenna port. The ordering of the precoder coefficients in coefficient subset A0 when rank index RI=2 is given as follows:

[0177]

number

[0178] According to the embodiment, each coefficient subset A i,j The precoder coefficients are ordered with respect to increasing polarization or polarization index. Precoder coefficients associated with the same polarization or polarization index are ordered with respect to increasing layer index. In some examples, there are two coefficient subsets. For the two coefficient subsets A0 and A1, each subset is associated with P' / 2 port indices for the first and second polarizations of the antenna port. The ordering of the precoder coefficients for coefficient subset A1 when rank index RI=2 is as follows:

[0179]

number

[0180] The following embodiments, according to sub-embodiment S1-3, use coefficient subset A i,j We propose an ordering scheme for the precoder coefficients. According to the embodiment, each coefficient subset A i,j The precoder coefficients are ordered with respect to the increasing layer index. Precoder coefficients associated with the same layer index are ordered with respect to the increasing port index.

[0181] In some examples, there are two coefficient subsets. For the two coefficient subsets A0 and A1, each subset is associated with P' / 2 port indices for the first and second polarizations of the antenna port. The ordering of the precoder coefficients for coefficient subset A0 when rank index RI=2 is given as follows:

[0182]

number

[0183] According to the embodiment, each coefficient subset A i,j The precoder coefficients are ordered with respect to the increasing port index. Precoder coefficients associated with the same port index are ordered with respect to the increasing layer index. In some examples, there are two coefficient subsets. For the two coefficient subsets A0 and A1, each subset is associated with P' / 2 port indices for the first and second polarizations of the antenna port. The ordering of the precoder coefficients in coefficient subset A0 when rank index RI=2 is given as follows:

[0184]

number

[0185] According to one embodiment, the bits of a bitmap in a channel state information CSI report used to indicate the position of non-zero precoding coefficients can be ordered in the same way as any one of the aforementioned precoder coefficient ordering schemes.

[0186] <Grouping scheme for precoder coefficients in channel state information CSI report for precoder formulation options 2 and 3> Hereafter, the terms "delayed and Doppler pair index" and "delayed and Doppler index pair" will be used interchangeably.

[0187] <Grouping related to port indexes> According to one embodiment, each precoder coefficient in the coefficient subset is associated with three indices (l, p, d). The first index l = 0, ..., RI-1 is the layer index. The second index p ∈ U is the port index. U = {0, ..., P'-1} or {0, ..., 2P'-1} is the set of port indices. The third index d = 0, ..., D'-1 is the delay and / or Doppler index, or the delay and Doppler pair index. If the selection of precoding coefficients is polarization-independent, the set U consists of P' port indices and is defined as U = {0, ..., P'-1}. Here, the precoder coefficient associated with port index p ∈ U is associated with the first or second polarization of the antenna port. If the selection of precoding coefficients is polarization-common, the set U consists of 2P' port indices and is defined as U = {0, ..., 2P'-1}. Here, the precoder coefficient associated with port index p ∈ {0, ..., P'-1} is associated with the first polarization of the antenna port. The precoder coefficient associated with port index p + P' is associated with the second polarization of the same antenna port. Therefore, the precoder coefficient associated with port index {0, ..., P'-1} is associated with the first polarization of the antenna port. The precoder coefficient associated with port index {P', ..., 2P'-1} is associated with the second polarization of the antenna port.

[0188] According to Embodiment S2, the precoder coefficients of the rank index RI layer of the precoding vector or matrix are a number of non-overlapping coefficient subsets A={A0,A1,…,A} in the channel state information CSI report. N-1 They are grouped into}. Each coefficient subset A iIt comprises precoder coefficients of D' delay and / or Doppler indices or D' delay and Doppler index pairs (D' ≤ D), and rank index RI layers associated with a number of port indices (number of port indices). The precoder coefficients of the i-th layer of the coefficient subset are associated with one subset of consecutive port indices from U, or with two subsets of consecutive port indices from U.

[0189] According to the embodiment, the first coefficient subset may be configured to include precoder coefficients related to the two polarizations of the antenna port. According to one embodiment, each coefficient subset may be configured to include precoder coefficients related to the two polarizations of the antenna port.

[0190] According to the embodiment, the i-th coefficient subset comprises a subset of the precoder coefficients of the rank index RI layer and D' delay and / or Doppler indices or D' delay and Doppler index pairs. The precoder coefficients of the l-th layer are B i,l Port Index (or B i,l (Associated with port index less than B) i,l A port index is defined by a subset of consecutive port indices starting from U, or B i,l The port index is defined by two subsets of the contiguous port index starting from U.

[0191] In some examples, port index B per coefficient subset i,l The number of elements may be the same for all rank index RI layers. In some examples, port index B i,l The number of coefficients is the total number of coefficients A i They are identical in this respect. In some examples, port index B i,l The number of coefficients is subset A i They are not identical across the spectrum.

[0192] In some examples, the coefficient subset {A0, A1, ..., A N-1 The} are ordered in the Channel Status Information CSI report with respect to the increasing subset index.

[0193] In an exemplary embodiment, there are 2P' precoder coefficients. P' precoder coefficients are associated with the first polarization of the antenna port. P' precoder coefficients are associated with the second polarization of the antenna port. The rank index RI layer precoder coefficients are grouped into two non-overlapping coefficient subsets (N=2) in the channel state information CSI report. The first coefficient subset A0 comprises precoder coefficients for all rank index RI layer indices and all delay and / or Doppler indices associated with the first P' / 2 port indices of the first polarization of the antenna port (p=0,...,P' / 2-1), and precoder coefficients for all rank index RI layer indices and all delay and / or Doppler indices associated with the first P' / 2 port indices of the second polarization of the antenna port (p=P'+0,...,P'+P' / 2-1). The second coefficient subset A1 comprises precoder coefficients for all rank index RI layer indices and all delay and / or Doppler indices related to the remaining P' / 2 port indices of the first polarization of the antenna port (p=P' / 2,…,P'-1), and precoder coefficients for all rank index RI layer indices and all delay and / or Doppler indices related to the remaining P' / 2 port indices of the second polarization of the antenna port (p=P'+P' / 2,…,2P'-1). Note that in some examples, P'=P.

[0194] In some examples, precoder selection is common to all polarizations. The rank index RI=2, P'=8, and D'=2. The set of port indices U is defined as U={0,…,15}. The selected port indices for layer 0 and layer 1 are {0,1,2,3,4,5,9,10,11,13,14,15} and {0,4,5,8,9,11,13,15}, respectively. Each coefficient subset consists of precoder coefficients associated with four port indices and all delay and / or Doppler indices for each polarization in both layers. The first coefficient subset A0 consists of precoder coefficients associated with the port indices {0,1,2,3,9,10,11} and {0,8,9,11} of layer 0 and layer 1, respectively. The second coefficient subset A1 consists of the port indices {4,5,13,14,15} of layer 0 and layer 1, respectively, and the precoder coefficients associated with {4,5,13,15}.

[0195] <Grouping based on the global port index> In one embodiment, each precoder coefficient in the coefficient subset is associated with two indices (l, p, d). The first index, l = 0, ..., RI-1, is the layer index. The second index, p ∈ U', is the global port index, where U' = {0, ..., P-1} or U' = {0, ..., 2P-1} is the set of global port indices. d = 0, ..., D'-1 is the delay and / or Doppler index or delay and Doppler pair index, where P represents the number of vectors in the first basis set. It is assumed that a mapping exists between the global port index p ∈ U' and the local port index p ∈ U. If the selection of precoding coefficients is polarization-independent, the set U' consists of P port indices and is defined as U' = {0, ..., P-1}, where the precoder coefficient associated with the port index p ∈ U' is associated with the first or second polarization of the antenna port. If the selection of precoding coefficients is common to all polarizations, the set U' consists of 2P global port indices and is defined as U' = {0, ..., 2P-1}. Here, the precoding coefficients associated with global port index p ∈ {0, ..., P-1} are associated with the first polarization of the antenna port, and the precoding coefficients associated with global port index p+P are associated with the second polarization of the same antenna port (see Figure 8).

[0196] In an exemplary embodiment, there are 2P' precoder coefficients, where P' precoder coefficients are associated with the first polarization of the antenna port and P' precoder coefficients are associated with the second polarization of the antenna port. The rank index RI layer precoder coefficients are grouped into two non-overlapping coefficient subsets (N=2) in the channel state information CSI report. The first coefficient subset A1 comprises precoder coefficients for all rank index RI layer indices associated with the first P' / 2 port indices of the first polarization of the antenna port (p=0,…,P' / 2-1) and all delay and / or Doppler indices, or all delay and Doppler pair indices, and precoder coefficients for all rank index RI layer indices associated with the first P' / 2 port indices of the second polarization of the antenna port (p=P'+0,…,P'+P' / 2-1) and all delay and / or Doppler indices, or all delay and Doppler pair indices. The second coefficient subset A2 comprises the precoder coefficients of all rank index RI layer indices associated with the remaining P' / 2 port indices of the first polarization of the antenna port (p=P' / 2,…,P' / 2-1) and all delay and / or Doppler indices, or all pairs of delay and Doppler indices, and the precoder coefficients of all rank index RI layer indices associated with the remaining P' / 2 port indices of the second polarization of the antenna port (p=P'+P' / 2,…,2P'-1) and all delay and / or Doppler indices. Note that in some examples, P'=P.

[0197] In one exemplary embodiment, there are 2P' or P' precoder coefficients. P' precoder coefficients are associated with the first polarization of the antenna port. P' precoder coefficients are associated with the second polarization of the antenna port. Or P' precoder coefficients are associated with the first and second polarizations of the antenna port. The rank index RI layer precoder coefficients are grouped into two non-overlapping coefficient subsets (N=2) in the channel state information CSI report. The first coefficient subset A1 comprises precoder coefficients for all rank index RI layer indices associated with the first P / 2 port indices of the first polarization (0,…,P / 2-1) of the antenna port and all delay and / or Doppler indices, or all delay and Doppler pair indices, and precoder coefficients for all rank index RI layer indices associated with the first P / 2 port indices of the second polarization (P+0,…,P+P / 2-1) of the antenna port and all delay and / or Doppler indices, or all delay and Doppler pair indices. The second coefficient subset A2 comprises the precoder coefficients for all rank index RI layer indices associated with the remaining P / 2 port indices of the first polarization (P / 2, ..., P-1) of the antenna port and all delay and / or Doppler indices or all delay-Doppler pair indices, and the precoder coefficients for all rank index RI layer indices associated with the remaining P / 2 port indices of the second polarization (P+P / 2, ..., 2P-1) of the antenna port and all delay and / or Doppler indices or all delay-Doppler index pair. Here, P represents the total number of basis indices of the basis vectors of the first basis set.

[0198] <Grouping of coefficient subsets> According to sub-embodiment S2-1, each coefficient subset A i The precoder coefficients are a subset of many coefficients A in the channel state information CSI report. i ={A i,1 ,…,A i,TIt can be further grouped into}. Each coefficient subset A i,j It comprises a rank index RI layer and a single delay and / or Doppler index or a delay and Doppler pair index, with associated precoder coefficients, in one subset or two subsets of continuous port indices from U′ or U′ related to the first and second polarizations of the antenna port. Coefficient subset A i,j These are ordered with respect to increasing delay and / or Doppler indexes or delay and Doppler pair indices.

[0199] According to sub-embodiment S2-2, each coefficient subset A i The precoder coefficients are further included in the channel state information CSI report, with a subset of coefficients A. i ={A i,1 ,…,A i,T They can be grouped into}. Each coefficient subset A i,j It comprises associated precoder coefficients for one or two subsets of continuous port indices U′ or U′ related to the first and second polarizations of the antenna port, all delay and / or Doppler indices or all delay and Doppler pair indices, and single-layer indices. Coefficient subset A i,j These are ordered with respect to the increasing layer index.

[0200] According to sub-embodiment S2-3, each coefficient subset A i The precoder coefficients are further included in the channel state information CSI report, with a subset of coefficients A. i ={A i,1 ,…,A i,T3 They can be grouped into}. Each coefficient subset A i,j is the coefficient subset A i The associated layer indices are comprised of all delay and / or Doppler indices or all delay and Doppler pair indices for single-polarization single-port indices, each with associated precoder coefficients. Coefficient subset Ai,j The coefficients are ordered with respect to the increasing port index. Subsets of coefficients associated with the same port index are ordered with respect to the increasing polarization index.

[0201] According to sub-embodiment S2-4, each coefficient subset A i The precoder coefficients are further included in the channel state information CSI report, with a subset of coefficients A. i ={A i,1 ,…,A i,T3 They can be grouped into}. Each coefficient subset A i,j is the coefficient subset A i The associated layer indices are comprised of all delay and / or Doppler indices or all delay and Doppler pair indices for single-polarization single-port indices, each with associated precoder coefficients. Coefficient subset A i,j These are ordered with respect to the increasing polarization index. Subsets of coefficients associated with the same polarization index are ordered with respect to the increasing port index.

[0202] <Ordering of precoder coefficients in a coefficient subset> The following exemplary embodiment, according to sub-embodiment S2-1, uses coefficient subset A i,j We propose an ordering scheme for precoder coefficients in this context.

[0203] According to one embodiment, each coefficient subset A i,j The precoder coefficients are ordered with respect to the increasing layer index. Precoder coefficients associated with the same layer index are ordered with respect to the increasing port index.

[0204] According to one embodiment, each coefficient subset A i,jThe precoder coefficients are ordered with respect to the increasing layer index. Precoder coefficients associated with the same layer index are ordered with respect to the increasing port index. Coefficients associated with the same port index are ordered with respect to the increasing polarization or polarization index.

[0205] In some examples, the number of coefficient subsets is two. For the two coefficient subsets A0 and A1, the precoder coefficients of each subset are associated with P' / 2 port indices for the first and second polarizations. The ordering of the precoder coefficients of coefficient subset A1 when rank indices RI=2,D'=2 is given as follows:

[0206]

number

[0207] According to the embodiment, each coefficient subset A i,j The precoder coefficients are ordered with respect to the increasing polarization index. Precoder coefficients associated with the same polarization index are ordered with respect to the increasing layer index. Coefficients associated with the same layer index are ordered with respect to the increasing port index.

[0208] In some examples, there are two coefficient subsets. For the two coefficient subsets A0 and A1, each subset is associated with P' / 2 port indices for the first and second polarizations. The ordering of the precoder coefficients for coefficient subset A1 when rank indices RI=2,D'=2 is given as follows:

[0209]

number

[0210] According to one embodiment, each coefficient subset A i,jThe precoder coefficients are ordered with respect to the increasing port index. Precoder coefficients associated with the same port index are ordered with respect to the increasing layer index.

[0211] According to one embodiment, each coefficient subset A i,j The precoder coefficients are ordered with respect to the increasing port index. Precoder coefficients associated with the same port index are ordered with respect to the increasing polarization index. Coefficients associated with the same polarization index are ordered with respect to the increasing layer index.

[0212] In some examples, there are two coefficient subsets. For the two coefficient subsets A0 and A1, each subset is associated with P' / 2 port indices for the first and second polarizations. The ordering of the precoder coefficients for coefficient subset A1 when rank indices RI=2,D'=2 is given as follows:

[0213]

number

[0214] According to one embodiment, each coefficient subset A i,j The precoder coefficients are ordered with respect to the increasing polarization index. Precoder coefficients associated with the same polarization index are ordered with respect to the increasing port index. Coefficients associated with the same port index are ordered with respect to the increasing layer index.

[0215] In some examples, there are two coefficient subsets. For the two coefficient subsets A0 and A1, each subset is associated with P' / 2 port indices for the first and second polarizations. The ordering of the precoder coefficients for coefficient subset A1 when rank indices RI=2,D'=2 is given as follows:

[0216]

number

[0217] The following exemplary embodiment, according to sub-embodiment S2-2, applies coefficient subset A i,j We propose an ordering scheme for the precoder coefficients. According to one embodiment, each coefficient subset A i,j The precoder coefficients are ordered with respect to the increasing port index. Precoder coefficients associated with the same port index are ordered with respect to the increasing delay and / or Doppler index or delay and Doppler pair index.

[0218] According to one embodiment, each coefficient subset A i,j The precoder coefficients are ordered with respect to the increasing port index. Precoder coefficients associated with the same port index are ordered with respect to the increasing polarization index. Precoder coefficients associated with the same polarization index are ordered with respect to the increasing delay and / or Doppler index or delay and Doppler pair index.

[0219] In some examples, there are two coefficient subsets. For the two coefficient subsets A0 and A1, each subset is associated with P' / 2 port indices for the first and second polarizations. The ordering of the precoder coefficients for coefficient subset A1 when rank indices RI=2,D'=2 is given as follows:

[0220]

number

[0221] According to one embodiment, each coefficient subset A i,jThe precoder coefficients are ordered with respect to the increasing polarization index. Precoder coefficients associated with the same polarization index are ordered with respect to the increasing port index. Precoder coefficients associated with the same port index are ordered with respect to the increasing delay and / or Doppler index or delay and Doppler pair index.

[0222] In some examples, the number of coefficient subsets is two. For the two coefficient subsets A0 and A1, each subset is associated with P' / 2 port indices for the first and second polarizations. The ordering of the precoder coefficients for coefficient subset A1 when rank indices RI=2,D'=2 is given as follows:

[0223]

number

[0224] According to one embodiment, each coefficient subset A i,j The precoder coefficients are ordered with respect to the increasing delay and / or Doppler index or delay and Doppler pair index. Precoder coefficients related to the same delay and / or Doppler index or delay and Doppler pair index are ordered with respect to the increasing port index.

[0225] According to one embodiment, each coefficient subset A i,j The precoder coefficients are ordered with respect to the increasing delay and / or Doppler index or delay and Doppler pair index. Precoder coefficients associated with the same delay and / or Doppler index or delay and Doppler pair index are ordered with respect to the increasing polarization index. Precoder coefficients associated with the same polarization index are ordered with respect to the increasing port index.

[0226] In some examples, there are two coefficient subsets. For the two coefficient subsets A0 and A1, each subset is associated with P' / 2 port indices for the first and second polarizations. The ordering of the precoder coefficients for coefficient subset A1 when rank indices RI=2,D'=2 is given as follows:

[0227]

number

[0228] According to one embodiment, each coefficient subset A i,j The precoder coefficients are ordered with respect to the increasing delay and / or Doppler index or delay and Doppler pair index. Precoder coefficients associated with the same delay and / or Doppler index or delay and Doppler pair index are ordered with respect to the increasing port index. Precoder coefficients associated with the same port index are ordered with respect to the increasing polarization index.

[0229] In some examples, there are two coefficient subsets. For the two coefficient subsets A0 and A1, each subset is associated with P' / 2 port indices for the first and second polarizations. The ordering of the precoder coefficients for coefficient subset A1 when rank indices RI=2,D'=2 is given as follows:

[0230]

number

[0231] The following exemplary embodiment, according to sub-embodiment S2-3, applies coefficient subset A i,j We propose an ordering scheme for the precoder coefficients. According to one embodiment, each coefficient subset A i,jThe precoder coefficients are ordered with respect to the increasing layer index. Precoder coefficients associated with the same layer index are ordered with respect to the increasing delay and / or Doppler index or delay and Doppler pair index.

[0232] In some examples, there are two coefficient subsets. For the two coefficient subsets A0 and A1, each subset is associated with P' / 2 port indices for the first and second polarizations. The ordering of the precoder coefficients for coefficient subset A1 when rank indices RI=2,D'=2 is given as follows:

[0233]

number

[0234] According to one embodiment, each coefficient subset A i,j The precoder coefficients are ordered with respect to the increasing delay and / or Doppler index or delay and Doppler pair index. Precoder coefficients associated with the same delay and / or Doppler index or delay and Doppler pair index are ordered with respect to the increasing layer index.

[0235] In some examples, there are two coefficient subsets. For the two coefficient subsets A0 and A1, each subset is associated with P' / 2 port indices for the first and second polarizations. The ordering of the precoder coefficients for coefficient subset A1 when rank indices RI=2,D'=2 is given as follows:

[0236]

number

[0237] The following exemplary embodiment, according to sub-embodiment S2-4, applies coefficient subset A i,jWe propose an ordering scheme for the precoder coefficients. According to the embodiment, each coefficient subset A i,j The precoder coefficients are ordered with respect to the increasing layer index. Precoder coefficients associated with the same layer index are ordered with respect to the increasing delay and / or Doppler index or delay and Doppler pair index.

[0238] In some examples, there are two coefficient subsets. For the two coefficient subsets A0 and A1, each subset is associated with P' / 2 port indices for the first and second polarizations. The ordering of the precoder coefficients of coefficient subset A1 for rank indices RI=2 and D'=2 is given as follows:

[0239]

number

[0240] According to one embodiment, each coefficient subset A i,j The precoder coefficients are ordered with respect to the increasing delay and / or Doppler index or delay and Doppler pair index. Precoder coefficients associated with the same delay and / or Doppler index or delay and Doppler pair index are ordered with respect to the increasing layer index.

[0241] In some examples, there are two coefficient subsets. For the two coefficient subsets A0 and A1, each subset is associated with P' / 2 port indices for the first and second polarizations. The ordering of the precoder coefficients of coefficient subset A1 for rank indices RI=2 and D'=2 is given as follows:

[0242]

number

[0243] According to one embodiment, bits in a bitmap within a channel state information CSI report used to indicate the location of non-zero precoding coefficients may be ordered in the same manner as any one of the aforementioned precoder coefficient ordering schemes.

[0244] <Ordering of FD indices in precoder formulation options 2 and 3> Precoder coefficients associated with the strongest coefficient basis vector index (from the second basis set) carry significantly more energy than the remaining precoder coefficients associated with other basis vector indexes. Therefore, these precoder coefficients have a greater impact on precoder performance and can have a higher priority than the remaining precoder coefficients (which have lower priority). To ensure that high-priority precoder coefficients (precoder coefficients associated with the strongest coefficient basis vector index) are not omitted when channel state information CSI omission occurs, the highest-priority precoder coefficients are placed at the beginning of the grouping or packing of precoder coefficients in the channel state information CSI report. For example, in the case of channel state information CSI omission, the user device UE will omit lower-priority precoder coefficients from the channel state information CSI report.

number

number

[0245] According to one embodiment, the precoder coefficients associated with the same layer index l (l=0,...,RI-1) and delay and / or Doppler index d (d=0,...,D-1 or d=0,...,D'-1) are the reference delay and / or Doppler index d associated with index l. r ∈{0,…,D-1} or d r With respect to ∈{0,…,D′-1}, the data is ordered or grouped according to a predefined rule or pattern within the channel state information CSI report.

[0246] According to the embodiment, the layer index l and the delay and / or Doppler index d are the same as the layer index and delay and / or Doppler index of the maximum or strongest coefficient. r The precoder coefficients associated with the new delay and / or Doppler index d' are ordered so that the ordered precoder coefficients are associated with the new delay and / or Doppler index d'=0. In this case, the reference delay and / or Doppler index d r This is defined by the delay and / or Doppler index associated with the maximum or strongest coefficient.

[0247] In exemplary embodiments, the precoder coefficient or delay and / or Doppler index is modulo d' = (dd r ) is ordered with respect to modulo D, where d' is the new delay and / or Doppler index (after modulo operation). r is the reference delay and / or Doppler index associated with the maximum or strongest coefficient. Note that the ordered precoder coefficients associated with the layer index and the same delay and / or Doppler index as the maximum or strongest coefficient are associated with the new delay and / or Doppler index d'=0.

[0248] In some examples, for D = 4, d = 0, 1, 2, 3, and for the l-th layer, the delay and / or Doppler index of the maximum or strongest coefficient is d r = 1. According to the above ordering, the pre - coder coefficient associated with the delay and / or Doppler index d r = 1 is associated with the new delay and / or Doppler index d′ = 0. The pre - coder coefficient associated with the delay and / or Doppler index d = 0 is associated with the new delay and / or Doppler index d′ = 3. The pre - coder coefficient associated with the delay and / or Doppler index d = 2 is associated with the new delay and / or Doppler index d′ = 1. The pre - coder coefficient associated with the delay and / or Doppler index d = 3 is associated with the new delay and / or Doppler index d′ = 2.

[0249] In an exemplary embodiment, the pre - coder coefficients or the delay and / or Doppler indices are ordered as follows. That is, the pre - coder coefficient associated with the same layer index and the same delay and / or Doppler index as the maximum coefficient or the strongest coefficient is associated with the new delay and / or Doppler index d′ = 0, and the remaining pre - coder coefficients associated with the same layer index and the remaining delay and / or Doppler indices are ordered with respect to increasing or decreasing delay and / or Doppler indices.

[0250] In some examples, for D = 4, d = 0, 1, 2, 3, and for the l - th layer, the delay and / or Doppler index of the maximum or strongest coefficient is r = 1. According to the above ordering, the delay and / or Doppler index d rPrecoder coefficients associated with =1 are associated with the new delay and / or Doppler index d'=0. Precoder coefficients associated with delay and / or Doppler index d=0 are associated with the new delay and / or Doppler index d'=1. Precoder coefficients associated with delay and / or Doppler index d=2 are associated with the new delay and / or Doppler index d'=2. Precoder coefficients associated with delay and / or Doppler index d=3 are associated with the new delay and / or Doppler index d'=3.

[0251] In some examples, when D=4, d=0,1,2,3, and for the lth layer, the delay and / or Doppler index of the maximum or strongest coefficient is d r = 1. According to the above ordering, the delay and / or Doppler index d r The precoder coefficient associated with =1 is associated with the new delay and / or Doppler index d'=0. The precoder coefficient associated with delay and / or Doppler index d=3 is associated with the new delay and / or Doppler index d'=2, the precoder coefficient associated with delay and / or Doppler index d=2 is associated with the new delay and / or Doppler index d'=3, and the precoder coefficient associated with delay and / or Doppler index d=0 is associated with the new delay and / or Doppler index d'=4.

[0252] According to one embodiment, the precoder coefficients for each layer relating to the set of basis vectors of the second basis set are ordered with respect to the basis index f of the basis vectors. In some examples, the precoder coefficients relating to the basis index f are the modulo operation f t =( ff r ) is ordered with respect to mod N3. Here f t ∈{0,…,N3-1} are the new basis indices (after modulo operation). rf is a reference basis index associated with the maximum or strongest coefficient. The ordered precoder coefficients associated with the same layer and delay as the maximum or strongest coefficient are the new basis index f t Note that this is associated with =0.

[0253] In some examples, D=4, f=0,1,11,12, N3=13, and for the l-th layer, the basis index of the largest or strongest coefficient is f r = 1. Following the ordering above, the precoder coefficients associated with the base index f = {0, 1, 11, 12} are the new base index f t It is mapped to {1,0,10,11}.

[0254] According to one embodiment, a new base index f t The precoder coefficients associated with =0 are mapped to the new delay and / or Doppler index d'=0.

[0255] According to one embodiment, f t A new base index f other than =0 t The precoder coefficients are mapped to a new delay and / or Doppler index d′ according to a specific ordering of the N3 delays.

[0256]

number

[0257] In some examples, when D=4, f t ={1,0,11,12}, and for the l-th layer, the basis index of the largest or strongest coefficient is f r = 1. According to the above ordering, the new base index f t The precoder coefficients associated with ={1,0,11,12} are mapped to the new delay and / or Doppler index d′={0,1,2,3} as follows:

[0258] Delay ft The precoder coefficient associated with =0 is associated with the new delay and / or Doppler index d'=0. Delay f t The precoder coefficient associated with =12 is associated with the new delay and / or Doppler index d'=1. Delay f t The precoder coefficient associated with =1 is associated with the new delay and / or Doppler index d'=2. Delay f t The precoder coefficient associated with =11 is associated with the new delay and / or Doppler index d'=3.

[0259] According to one embodiment, the channel status information CSI report includes a display showing the reference delay and / or Doppler index. In some examples, the indicators showing the reference delay and / or Doppler index are

number

number

[0260] According to the embodiment, the grouping of precoder coefficients into at least two coefficient subsets, and the ordering of coefficient subsets and precoder coefficients within each coefficient subset, are based on a new delay and / or Doppler index d' instead of the delay and / or Doppler index d.

[0261] A user device UE is also provided to perform the aforementioned processing or method steps performed by the user device UE. Figure 9 is a block diagram of the user device UE 900. The user device UE 900 comprises a processor 910 or processing circuit or processing module or a processor or means 910, a receiving circuit or receiving module 940, a transmitting circuit or transmitting module 950, a memory module 920, and a transceiver circuit or transceiver module 930 which may include the transmitting circuit 950 and the receiving circuit 940. The user device UE 900 further comprises an antenna port system 960 which has an antenna circuit for sending and receiving signals to and from at least network nodes. The antenna port system 960 employs beamforming as described above.

[0262] As described above, the user device UE900 is configured to perform the following steps: receiving a channel status information CSI report configuration from a network node; determining the number (numerous, number of) of precoder coefficients in the rank index (RI) transmission layer of the precoder vector or matrix based on the received channel status information CSI report configuration; grouping the precoder coefficients of the rank index RI transmission layer into at least two coefficient subsets, each coefficient subset comprising multiple precoder coefficients; assigning an order to the at least two coefficient subsets and assigning an order to the precoder coefficients within each coefficient subset; dividing the at least two coefficient subsets into two or more channel status information CSI groups having associated priority levels; and generating a channel status information CSI report consisting of channel status information CSI part 1 and channel status information CSI part 2. Channel status information CSI part 1 has a fixed payload size and includes information indicating the payload size of channel status information CSI part 2. The Channel State Information CSI Part 2 comprises precoder coefficients for at least one of two Channel State Information CSI groups. The process involves transmitting or reporting Uplink Control Information (UCI), which includes a Channel State Information CSI report, to network nodes via an Uplink (UL) channel. These steps are performed.

[0263] The additional actions performed by the user device UE900 have already been described, so there is no need to repeat them. The user device UE900 may belong to any radio access technology that includes 4G or LTE, LTE-A, 5G, Advanced 5G, or a combination thereof, which supports beamforming technology. The user device UE, which includes a processor and memory, has instructions that can be executed by the processor. Thereafter, the user device UE900 is made operable or configured to perform any one of the embodiments relating to the user device UE described above.

[0264] The processing module / circuit 910 comprises a processor, microprocessor, application-specific integrated circuit (ASIC), field-programmable gate array (FPGA), etc., and is sometimes referred to as a “processor.” The processor 910 controls the operation of the network node and its components. The memory (circuit or module) 920 comprises random access memory (RAM), read-only memory (ROM), and / or other types of memory for storing data and instructions that may be used by the processor 910. Generally, it will be understood that a network node in one or more embodiments comprises fixed or programmed circuitry configured to perform the operation in any of the embodiments disclosed herein.

[0265] In at least one such embodiment, the processor 910 comprises a microprocessor, microcontroller, DSP, ASIC, FPGA, or other processing circuit configured to execute computer program instructions from a computer program stored in a non-transient (non-temporary) computer-readable medium that resides within or is accessible to the processing circuit. Here, “non-transient” does not necessarily mean persistent or immutable storage, and may include storage in working memory or volatile memory, but the term means storage with at least some degree of persistence. Execution of program instructions specially adapts or configures the processing circuit to perform the operations disclosed in this disclosure relating to the user device UE. Furthermore, it will be understood that the user device UE 900 may be configured with additional components.

[0266] A network node (or gNB) is also provided to perform the aforementioned processing or method steps performed by the network node. Figure 10 is an exemplary block diagram of network node 1000. Network node 1000 comprises a processor 1010 or processing circuit or processing module or processor or means 1010, a receiving circuit or receiving module 1040, a transmitting circuit or transmitting module 1050, a memory module 1020, and a transceiver circuit or transceiver module 1030 which may include the transmitting circuit 1050 and the receiving circuit 1040. Network node 1000 further comprises an antenna system 1060 which has an antenna circuit for sending and receiving signals to and from at least user equipment UE. The antenna port system 1060 employs beamforming as described above. The operations performed by network node 1000 have already been described. Network node 1000 can also be considered as a transmit and receive point (transmitter and receiver point: TRP).

[0267] The processing module / circuit 1010 comprises a processor, microprocessor, application-specific integrated circuit (ASIC), field-programmable gate array (FPGA), etc., and is sometimes referred to as a “processor.” The processor 1010 controls the operation of the network node and its components. The memory (circuit or module) 1020 comprises random access memory (RAM), read-only memory (ROM), and / or other types of memory for storing data and instructions that may be used by the processor 1010. Generally, it will be understood that a network node in one or more embodiments comprises fixed or programmed circuitry configured to perform the operation in any of the embodiments disclosed herein.

[0268] In at least one such example, the processor 1010 comprises a microprocessor, microcontroller, DSP, ASIC, FPGA, or other processing circuit configured to execute computer program instructions from a computer program stored in a non-transient (non-temporary) computer-readable medium that resides within or is accessible to the processing circuit. Here, “non-transient” does not necessarily mean persistent or immutable storage, and may include storage in working memory or volatile memory, but the term means storage of at least some degree of persistence. Execution of program instructions specially adapts or configures the processing circuit to perform the operations disclosed herein. Furthermore, it will be understood that the network node 1000 may be configured with additional components.

[0269] The network node 1000 may belong to any radio access technology having 4G or LTE, LTE-A, 5G, Advanced 5G, or a combination thereof, which supports beamforming technology. The network node 1000 comprises a processor and memory having instructions that can be executed by the processor. Thereafter, the network node 1000 is made operable or configured to perform any one of the subject matter presented in this disclosure relating to a network node (or gNB).

[0270] As described above, the network node 1000 is configured to perform the following steps: Transmit a channel status information CSI report configuration to the user equipment UE, based on the transmitted channel status information CSI report configuration, to enable the user equipment UE to determine the number (numerous, number of) of precoder coefficients for the rank index RI transmission layer of the precoder vector or matrix. Transmit an uplink control information UCI from the user equipment UE via the uplink channel, which includes a channel status information CSI report generated by the user equipment UE. The channel status information CSI report comprises channel status information CSI part 1 and channel status information CSI part 2. Channel status information CSI part 1 has a fixed payload size and includes information indicating the payload size of channel status information CSI part 2. Channel status information CSI part 2 includes precoder coefficients for at least one group of two or more channel status information CSI groups. The precoder coefficients are ordered into at least two ordered coefficient subsets.

[0271] Additional details regarding the functions and operations performed by the network nodes have already been described, so there is no need to repeat them. Some of the advantages of the embodiments described in this disclosure have already been described. These include a significant reduction in the feedback overhead and computational complexity at the user equipment UE for codebook-based channel status information CSI reporting, assuming that information on the angle and delay of the multipath components of the channel is available at the base station or network node. Another advantage is that the latency of the channel status information CSI reporting can be reduced.

[0272] Throughout this specification, any reference to “example” or “exemplary” means that a particular feature, structure, or characteristic described in relation to the example is included in at least one embodiment of the Art. Therefore, when the phrase “example” or “exemplary” appears in various places throughout this specification, it does not necessarily refer to the same embodiment.

[0273] Throughout this disclosure, the terms “comprise” or “comprising” are used in a non-limiting sense, i.e., “consisting of at least.” Certain terms may be used herein, but these are used only in a general and descriptive sense and are not intended to be limiting. Embodiments described herein may apply to any wireless system comprising LTE or 4G, LTE-A (or LTE-Advanced), 5G, Advanced 5G, WiMAX, WiFi, satellite communications, television broadcasting, etc.

Claims

1. A method performed by a user device (900) for generating and reporting a channel status information CSI report in a wireless communication system, wherein the method is: The process of receiving channel status information CSI report configuration from a network node (401), The process involves determining the number of precoder coefficients in the rank index RI transmission layer of the precoder vector or matrix based on the received channel state information CSI report configuration (402), A step of grouping (403) the precoder coefficients of the rank index RI transmitting layer into at least two coefficient subsets, wherein each coefficient subset comprises a plurality of precoder coefficients, The steps include assigning (404) the ordering to at least two subsets of coefficients and the ordering to the precoder coefficients within each subset of coefficients, The steps include dividing the aforementioned at least two coefficient subsets into two or more channel state information CSI groups having associated priority levels (405), A step (406) to generate a channel state information CSI report comprising channel state information CSI part 1 and channel state information CSI part 2, wherein channel state information CSI part 1 has a fixed payload size and includes information indicating the payload size of channel state information CSI part 2, and channel state information CSI part 2 includes precoder coefficients for at least one group out of two or more channel state information CSI groups, The steps include transmitting the uplink control information UCI, which includes the channel status information CSI report, to the network node via the uplink UL channel (407), It is equipped with, Each precoder coefficient is associated with one of four indices (l, p, d, n). The first index, l, is a layer index. The second index, p, is the port or spatial beam index. The third index, d, is a lazy index. The fourth index, n, is the Doppler component index. The step of grouping the precoder coefficients of the rank index RI transmitting layer into at least two coefficient subsets (403) is based on at least one of the delay index d and the Doppler component index n. In the channel state information CSI report, the precoder coefficients for the rank index RI transmitting layer of the precoder vector or matrix are ordered based on the Doppler component index n. method.

2. l = 0, ..., RI - 1, p = 0, ..., P'-1 or p = 0, ..., 2P'-1, d = 0, ..., D'-1, n = 0, ..., E'-1, P' is the number of ports, D' is the number of delays, E' is the number of Doppler components. The method according to claim 1.

3. The precoder coefficients of the rank index RI layer of the precoded vector or matrix are a subset of many non-overlapping coefficients A = {A ０ , A １ , ..., A Ｎ－１ They are grouped under}, Each coefficient subset A ｉ It comprises D' delay and rank index precoder coefficients associated with the RI transmission layer, and a number of port indices. The method according to claim 2.

4. Each coefficient subset A ｉ The aforementioned precoder coefficients are further a subset A of many coefficients. ｉ = {A ｉ，１ , ..., A ｉ，Ｔ They are grouped under}, Each coefficient subset A ｉ，ｊ is configured to include precoder coefficients related to one subset or two subsets of consecutive port indexes related to the first and second polarizations of an antenna port, a rank index RI layer, and a single delay index. The method according to claim 3.

5. The aforementioned coefficient subset A ｉ，ｊ These are ordered with respect to the increasing delay index, Each coefficient subset A ｉ，ｊ The aforementioned precoder coefficients are ordered with respect to the increasing port index, The aforementioned precoder coefficients related to the same port index are ordered with respect to the increasing layer index. The method according to claim 4.

6. The aforementioned subset of coefficients is ordered with respect to the increasing subset index. The method according to claim 3.

7. Grouping of the precoder coefficients into at least two coefficient subsets, The ordering of the coefficient subset and the precoder coefficients within each coefficient subset, This is based on a new delay index d' instead of the delay index d, The method according to claim 2.

8. The precoder vector for the transmission layer is, From a first basis set having P basis vectors, P' selected basis vectors, D′ selected basis vectors from a second basis set having D basis vectors, E′ selected basis vectors from a third basis set having E basis vectors, and, A set of precoder coefficients for joining selected basis vectors from the first, second, and third basis sets, Based on, The method according to claim 2.

9. D' = D, The precoder coefficient or the delay index is calculated using the modulo operation d' = (d - d ｒ ) are ordered with respect to modD, d' is the new delayed index after the modulo operation, d ｒ This is a reference delay index related to the maximum or strongest coefficient. The method according to claim 8.

10. Each basis vector from the second basis set is N ３ A discrete Fourier transform (DFT) or inverse discrete Fourier transform (IDFT) vector defined over individual subbands or physical resource blocks (PRB) or frequency units, and associated with a delay value. Each basis vector from the third basis set is N ４ A discrete Fourier transform (DFT) or inverse discrete Fourier transform (IDFT) vector defined over time instants and associated with Doppler values, The method according to claim 8.

11. The first basis set is given by a 2D-DFT matrix of the 2D Discrete Fourier Transform, Each basis vector is called a spatial beam or spatial beam vector. The method according to claim 8.

12. The precoder coefficients for each layer relating to the set of basis vectors of the second basis set are ordered with respect to the basis index f of the basis vectors, The precoder coefficients related to the basis index f are obtained by modulo operation f ｔ = (f - f ｒ ) modN ３ If they are ordered in relation to, f ｔ ∈{0, ..., N} ３ -1} is a new base index, f ｒ This is the reference basis index associated with the largest or strongest coefficient. The method according to claim 10.

13. The aforementioned new base index f ｔ The precoder coefficient associated with = 0 is mapped to the new delay index d' = 0, f ｔ A new base index f other than =0 ｔ The aforementioned precoder coefficient is given by the following equation: N ３ The delays are mapped to a new delay and / or Doppler index d' according to a specific order of delays. [Math 1] The method according to claim 12.

14. The precoder coefficients of the layer are stacked within the coefficient matrix, The channel state information CSI report includes an indicator for showing the position of non-zero coefficients in the coefficient matrix. The indicator is provided by a bitmap. Each bit in the bitmap is associated with a precoder coefficient in the coefficient matrix, The method according to claim 1.

15. The bits in the bitmap are similarly ordered by the coefficient subset and the precoder coefficients within the coefficient subset. The method according to claim 14.

16. A method performed by a network node (1000) to receive a channel status information CSI report generated by a user device UE (900) in a wireless communication system, wherein the method is: A step of transmitting a channel state information CSI report configuration to the user device UE (900) that enables the user device UE to determine the number of precoder coefficients for the rank index RI transmission layer of the precoder vector or matrix based on the transmitted channel state information CSI report configuration, A step of grouping the precoder coefficients of the rank index RI transmitting layer into at least two coefficient subsets, wherein each coefficient subset comprises a plurality of precoder coefficients; A step of assigning an order to at least two subsets of coefficients, and an order to the precoder coefficients within each subset of coefficients, The steps include dividing the aforementioned at least two coefficient subsets into two or more channel state information CSI groups having associated priority levels, A step of receiving uplink control information UCI from the user device UE (900) via an uplink channel, the UCI having a channel status information CSI report generated by the user device UE, wherein the channel status information CSI report comprises a channel status information CSI part 1 and a channel status information CSI part 2, the channel status information CSI part 1 has a fixed payload size and includes information indicating the payload size of the channel status information CSI part 2, and the channel status information CSI part 2 includes the precoder coefficients of at least one group among two or more channel status information CSI groups. Each precoder coefficient is associated with one of four indices (l, p, d, n). The first index, l, is a layer index. The second index, p, is the port or spatial beam index. The third index, d, is a lazy index. The fourth index, n, is the Doppler component index. The precoder coefficients of the rank index RI transmitting layer are grouped into at least two coefficient subsets (403) based on at least one of the delay index d and the Doppler component index n. In the channel state information CSI report, the precoder coefficients for the rank index RI transmitting layer of the precoder vector or matrix are ordered based on the Doppler component index n. method.

17. A user device (900) comprising a processor (910) and memory (920), The memory (920) is equipped with instructions that can be executed by the processor (910), and the user device (900) is thus operable to perform the method according to any one of claims 1 to 15. User equipment (900).

18. A network node (1000) comprising a processor (1010) and memory (1020), The memory (1020) is equipped with instructions that can be executed by the processor (1010), so that the network node (1000) is operable to perform the method according to claim 16. Network node (1000).

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