Mapping of windowed FD-based combined indices for reporting and use of PMI

Abstract

To provide techniques for easily determining a precoding matrix indicator (PMI).SOLUTION: User equipment (UE) determines a precoder matrix indicator (PMI) at least by: determining an intermediate set of vectors from a frequency-domain (FD) codebook; forming a subset of the intermediate set of vectors; mapping the subset of vectors to a combinatorial indicator il; and forming the PMI at least from the combinatorial indicator. The UE sends the PMI toward a wireless network. A base station receives the PMI from the UE. The PMI includes a combinatorial indicator that maps to a subset of vectors from the FD codebook. The base station determines, using at least the received PMI, information from at least the FD codebook to apply to data for transmission toward the UE.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] This invention generally relates to feedback in wireless communication systems, and more specifically to PMI (Precoder Matrix Index) and similar feedback. [Background technology]

[0002] In wireless communication systems, specifically cellular systems, channel status information (CSI) is determined by the user equipment (UE), and several indicators corresponding to the CSI are fed back from the UE to the wireless network. One such indicator is the precoding matrix index (PMI), which allows the wireless network to select information from a codebook and apply that information to the data to be transmitted to the UE.

[0003] Recently, a new codebook and PMI feedback process have been proposed. There are several issues with PMI selection and reporting under this new scheme, as detailed below.

[0004] The attached drawings include the following figures. [Brief explanation of the drawing]

[0005] [Figure 1] This is a block diagram of one exemplary system, which may and may not be limited to exemplary embodiments. [Figure 2] This is a logic flow diagram for the feedback and use of channel state information, illustrating the operation of one or more exemplary methods, the results of executing computer program instructions embodied in computer-readable memory, functions performed by logic implemented in hardware, and / or the operation of interconnection means for performing functions according to exemplary embodiments. [Figure 3] An exemplary embodiment shows uplink control information (UCI) related to an extended Type II PMI (Precoder Matrix Index) report for layer l. [Figure 4] An illustrative diagram shows a sliding window mechanism using FD codebook indices (0-21) in the frequency domain, according to an exemplary embodiment, and a corresponding mapping using a window of size 2M=14 and initial point Minitial=-6. [Figure 5] FD base subset when a sliding window mechanism is applied, according to an exemplary embodiment.

number

[0006] This section is intended to provide examples, not to limit the scope.

[0007] In an exemplary embodiment, a method is disclosed that includes determining a precoding matrix index by a user device. Determining a precoding matrix index includes determining an intermediate set of vectors from a frequency-domain codebook, forming a subset of the intermediate set of vectors, mapping the subset of vectors to a combination index, and forming a precoding matrix index from at least the combination index. The method also includes transmitting the precoding matrix index to a wireless network by the user device.

[0008] Further exemplary embodiments include a computer program comprising code for performing the method of the previous paragraph when the computer program is executed on a processor. The computer program is a computer program product comprising a computer-readable medium having computer program code embodied therein for use with a computer. Another example is a computer program according to this paragraph, the program being directly loadable into the internal memory of a computer.

[0009] An exemplary apparatus includes one or more processors and one or more memories including computer program code. The one or more memories and the computer program code, together with the one or more processors, cause the apparatus to perform operations including determining, by a user equipment, a precoding matrix indicator, including determining an intermediate set of vectors from a frequency-domain codebook, forming a subset of the intermediate set of vectors, mapping the subset of vectors to a combination indicator, and forming at least the precoding matrix indicator from the combination indicator; and transmitting, by the user equipment, the precoding matrix indicator towards a wireless network.

[0010] An exemplary computer program product includes a computer-readable storage medium having computer program code embodied therein for use with a computer. The computer program code includes code for determining a precoding matrix indicator by a user equipment, the code including determining an intermediate set of vectors from a frequency domain codebook, forming a subset of the intermediate set of vectors, mapping the subset of vectors to a combination indicator, and forming the precoding matrix indicator from at least the combination indicator, and code for transmitting the precoding matrix indicator by the user equipment towards a wireless network.

[0011] In another exemplary embodiment, the apparatus comprises means for performing, by a user equipment, determining a precoding matrix indicator, the determining including determining an intermediate set of vectors from a frequency domain codebook, forming a subset of the intermediate set of vectors, mapping the subset of vectors to a combination indicator, and forming the precoding matrix indicator from at least the combination indicator, and transmitting the precoding matrix indicator by the user equipment to a wireless network.

[0012] In an exemplary embodiment, a method is disclosed that includes receiving, at a base station, a precoding matrix indicator from a user equipment. The precoding matrix indicator includes a combination indicator that maps to a subset of vectors from a frequency domain codebook. The method also includes determining, using at least the received precoding matrix indicator, information to apply to data for transmission to the user equipment from at least the frequency domain codebook.

[0013] Further exemplary embodiments include a computer program that includes code for performing the method of the preceding paragraph when the computer program is executed on a processor. The computer program according to this paragraph is a computer program product that includes a computer-readable medium having computer program code embodied therein for use with a computer. Another example is a computer program according to this paragraph, the program being directly loadable into the internal memory of a computer.

[0014] An exemplary device includes one or more processors and one or more memories containing computer program code. The one or more memories and the computer program code, together with the one or more processors, are configured to cause the device to perform operations including receiving precoding matrix indices from user equipment at a base station, wherein the precoding matrix indices include combination indices that map to a subset of vectors from a frequency-domain codebook, and using at least the received precoding matrix indices to determine information to apply to data to be transmitted to the user equipment from at least the frequency-domain codebook.

[0015] An exemplary computer program product includes a computer-readable storage medium having computer program code embodied therein for use with a computer. The computer program code includes a code for receiving precoding matrix indices from user equipment at a base station, wherein the precoding matrix indices include combination indices that map to a subset of vectors from a frequency-domain codebook; and a code for using at least the received precoding matrix indices to determine information to apply to data to be transmitted to the user equipment from at least the frequency-domain codebook.

[0016] In another exemplary embodiment, the device includes means for a base station to receive precoding matrix indices from user equipment, wherein the precoding matrix indices include a combination index that maps to a subset of vectors from a frequency-domain codebook, and to use at least the received precoding matrix indices to determine information to apply to data to be transmitted to the user equipment from at least the frequency-domain codebook. [Modes for carrying out the invention]

[0017] The following abbreviations, which may appear in this specification and / or in the drawings, are defined as follows:

[0018] 3GPP Third Generation Partnership Project

[0019] 5G (5th generation)

[0020] 5GC 5G Core Network

[0021] AMF access and mobility management functions

[0022] CSI Channel Status Information

[0023] CU Integration Unit

[0024] DU Distributed Unit

[0025] eNB (or eNodeB) Advanced NodeB (e.g., LTE base station)

[0026] EN-DC E-UTRA-NR Dual Connectivity

[0027] A node that provides termination for NR user plane protocols and control plane protocols to en-gNB or En-gNB UE, and functions as a secondary node in EN-DC.

[0028] E-UTRA Advanced Universal Terrestrial Radio Access, i.e., LTE radio access technology

[0029] FD frequency domain

[0030] gNB (or gNodeB) is a 5G / NR base station, i.e., a node that provides termination for the NR user plane protocol and control plane protocol to the UE, and is connected to the 5GC via the NG interface.

[0031] I / F Interface

[0032] LTE Long-Term Evolution

[0033] MAC Media Access Control

[0034] MME Movement Management Entity

[0035] ng or NG next generation

[0036] ng-eNB or NG-eNB Next-generation eNB

[0037] NR new radio

[0038] N / W or NW Network

[0039] NZC (Non-Zero Coefficient)

[0040] PDCP Packet Data Convergence Protocol

[0041] PHY Physical Layer

[0042] PMI Precoder Matrix Index

[0043] RA reference amplitude

[0044] RAN (Radio Access Network)

[0045] Rel Release

[0046] RLC Wireless Link Control

[0047] RRH Remote Wireless Headset

[0048] RRC (Radio Resource Control)

[0049] RU Wireless Unit

[0050] Rx receiver

[0051] SCI Strongest Coefficient Index

[0052] SD spatial domain

[0053] SDAP Service Data Adaptive Protocol

[0054] SGW Serving Gateway

[0055] SMF session management function

[0056] TS Technical Specifications

[0057] Tx transmitter

[0058] UCI Uplink Control Information

[0059] UE User devices (e.g., wireless devices, typically mobile devices)

[0060] UPF User Plane Functionality

[0061] The term “exemplary” is used herein to mean “serving as an example, illustration, or illustration.” Any embodiment described herein as “exemplary” should not necessarily be construed as being preferable or advantageous to other embodiments. All embodiments described in the embodiments for carrying out this invention are exemplary embodiments provided to enable those skilled in the art to create or use the invention and do not limit the scope of the invention as defined by the claims.

[0062] Exemplary embodiments herein describe techniques for mapping windowed FD bases to combined indices for reporting and use of PMI. Further descriptions of these techniques are presented after a description of systems in which the exemplary embodiments may be used.

[0063] Referring to Figure 1, this figure shows a block diagram of one exemplary system, which may and may not be limited, in which exemplary embodiments may be carried out. A user device (UE) 110, a radio access network (RAN) node 170, and network elements 190 are shown. In Figure 1, the user device (UE) 110 is communicating wirelessly with a wireless network 100. The UE is a wireless device, typically a mobile device, that can access the wireless network. The UE 110 includes one or more processors 120, one or more memories 125, and one or more transceivers 130 interconnected via one or more buses 127. Each of the one or more transceivers 130 includes a receiver Rx, 132 and a transmitter Tx, 133. The one or more buses 127 may be an address bus, a data bus, or a control bus, and may include any interconnection mechanism, such as a series of lines on a motherboard or integrated circuit, optical fiber or other optical communication equipment, and similar. The one or more transceivers 130 are connected to one or more antennas 128. One or more memories 125 contain computer program code 123. The UE 110 includes a control module 140 which contains one or both of parts 140-1 and / or 140-2, which can be implemented in various ways. The control module 140 may be implemented in hardware as control module 140-1, for example, as part of one or more processors 120. The control module 140-1 may also be implemented as an integrated circuit or via other hardware such as a programmable gate array. In another example, the control module 140 may be implemented as control module 140-2, which is implemented as computer program code 123 and executed by one or more processors 120. For example, one or more memories 125 and computer program code 123 together with one or more processors 120 may be configured to cause the user device 110 to perform one or more of the operations described herein. The UE 110 communicates with the RAN node 170 via a wireless link 111.

[0064] RAN node 170 is a base station that provides access to the wireless network 100 by wireless devices such as UE 110. RAN node 170 may be a base station for 5G, also known as New Radio (NR). In 5G, RAN node 170 may be an NG-RAN node, defined as either a gNB or an ng-eNB. A gNB is a node that provides termination of the NR user plane protocol and control plane protocol to the UE and is connected to the 5GC (e.g., network element(s) 190) via an NG interface. An ng-eNB is a node that provides termination of the E-UTRA user plane protocol and control plane protocol to the UE and is connected to the 5GC via an NG interface. An NG-RAN node may contain multiple gNBs, and a gNB may also contain aggregate units (CUs) (gNB-CUs) 196 and distributed units (DUs) (gNB-DUs). A DU 195 of a gNB is shown. Note that a DU may contain a radio unit (RU) or be coupled to a radio unit (RU) to control the radio unit (RU). A gNB-CU is a logical node that hosts the RRC, SDAP, and PDCP protocols of gNB, or the RRC and PDCP protocols of en-gNB, and controls the operation of one or more gNB-DUs. The gNB-CU terminates the F1 interface connected to it. The F1 interface is illustrated as reference 198, which also illustrates links between remote and centralized elements of RAN node 170, such as between gNB-CU 196 and gNB-DU 195. A gNB-DU is a logical node that hosts the RLC, MAC, and PHY layers of gNB or en-gNB, and its operation is partially controlled by a gNB-CU. One gNB-CU supports one or more cells. A single cell is supported by only one gNB-DU. A gNB-DU terminates the F1 interface 198 connected to the gNB-CU.DU195 is thought to include transceiver 160 as part of a RU, for example, but it should be noted that in some examples, transceiver 160 may be part of a separate RU that is under the control of DU195 and connected to DU195. RAN node 170 may also be an eNB (Advanced NodeB) base station for LTE (Long-Term Evolution), or any other suitable base station.

[0065] RAN node 170 includes one or more processors 152, one or more memories 155, one or more network interfaces (N / WI / F(or more)) 161, and one or more transceivers 160, all interconnected via one or more buses 157. Each of the transceivers 160 includes a receiver Rx,162 and a transmitter Tx,163. One or more transceivers 160 are connected to one or more antennas 158. One or more memories 155 contain computer program code 153. CU 196 may include processor(s) 152, memory 155, and network interface 161. DU 195 may also include its own memory(s) and processor(s), and / or other hardware, but these are not shown.

[0066] RAN node 170 includes a control module 150 which includes one or both of parts 150-1 and / or 150-2, which can be implemented in various ways. Control module 150 may be implemented in hardware as control module 150-1, for example, as part of one or more processors 152. Control module 150-1 may also be implemented as an integrated circuit or via other hardware such as a programmable gate array. In another example, control module 150 may be implemented as control module 150-2, which is implemented as computer program code 153 and executed by one or more processors 152. For example, one or more memories 155 and computer program code 153, together with one or more processors 152, are configured to cause RAN node 170 to perform one or more of the operations described herein. Note that the functionality of control module 150 may be distributed, for example, between DU195 and CU196, or it may be implemented only in DU195.

[0067] One or more network interfaces 161 communicate over the network, such as via links 176 and 131. Two or more RAN nodes 170 communicate, for example, using link 176. Link 176 can be wired, wireless, or both, and can implement, for example, an Xn interface for 5G, an X2 interface for LTE, or other suitable interfaces for other standards.

[0068] One or more buses 157 may be address buses, data buses, or control buses and may include any interconnection mechanisms such as a series of lines on a motherboard or integrated circuit, optical fibers or other optical communication equipment, wireless channels, and similar. For example, one or more transceivers 160 may be implemented as a remote radio head (RRH) 195 for LTE or a distributed unit (DU) 195 for gNB implementation for 5G, and other elements of the RAN node 170 may be located in a physically separate location from the RRH / DU, and one or more buses 157 may be partially implemented, for example, as optical fiber cables or other suitable network connections to connect other elements of the RAN node 170 (e.g., aggregation units (CUs), gNB-CUs) to the RRH / DU 195. Reference 198 also indicates those suitable network links(s).

[0069] The wireless network 100 may include one or more network elements 190 that may include core network functions and provide connectivity to further networks such as telephone networks and / or data communication networks (e.g., the Internet) via one or more links 181. Such core network functions for 5G may include access and mobility management functions (AMF(multiple)) and / or user plane functions (UPF(multiple)) and / or session management functions (SMF(multiple)). Such core network functions for LTE may include MME (Mobility Management Entity) / SGW (Serving Gateway) functions. It should be noted that these are merely illustrative functions that may be supported by the network element(multiple) 190, and both 5G and LTE functions may be supported. The RAN node 170 is coupled to the network element 190 via link 131. Link 131 can be implemented, for example, as an NG interface for 5G, or an S1 interface for LTE, or other suitable interfaces for other standards. The network element 190 includes one or more processors 175, one or more memories 171, and one or more network interfaces (N / WI / F(multiple)) 180, all interconnected via one or more buses 185. One or more memories 171 contain computer program code 173. The one or more memories 171 and the computer program code 173, together with the one or more processors 175, are configured to cause the network element 190 to perform one or more operations.

[0070] The wireless network 100 may perform network virtualization, which is the process of combining hardware and software network resources and network functions to create a virtual network that is a single software-based management entity. Network virtualization is accompanied by platform virtualization, which is often combined with resource virtualization. Network virtualization can be classified into either external network virtualization, which combines numerous networks or network parts to create a virtual unit, or internal network virtualization, which provides network-like functionality to a software container on a single system. It should be noted that the virtualized entity resulting from network virtualization is further implemented at some level using hardware such as processors 152 or 175 and memory 155 and 171, and such a virtualized entity produces technical effects.

[0071] Computer-readable memories 125, 155, and 171 can be of any type suitable for the local technical environment and can be implemented using any suitable data storage technology, such as semiconductor-based memory devices, flash memory, magnetic memory devices and systems, optical memory devices and systems, fixed memory, and removable memory. Computer-readable memories 125, 155, and 171 can be means for performing storage functions. Processors 120, 152, and 175 can be of any type suitable for the local technical environment and may include, in non-limiting examples, one or more of general-purpose computers, dedicated computers, microprocessors, digital signal processors (DSPs), and processors based on multicore processor architectures. Processors 120, 152, and 175 can be means for performing functions, such as controlling functions of UE 110, RAN node 170, etc., as described herein.

[0072] In general, various embodiments of the user device 110 may include, but are not limited to, cellular phones such as smartphones, tablets, personal digital assistants (PDAs) with wireless communication capabilities, portable computers with wireless communication capabilities, vehicles equipped with modem devices for V2X (Vehicle-to-Everything, i.e., vehicle-to-vehicle / vehicle-to-infrastructure communication) wireless communication, image capture devices such as digital cameras with wireless communication capabilities, game devices with wireless communication capabilities, music storage and playback devices with wireless communication capabilities, internet devices (including the Internet of Things, IoT, and devices) that enable wireless internet access and possibly browsing, IoT devices equipped with sensors and / or actuators for automation applications using wireless communication tablets with wireless communication capabilities, and portable units or terminals incorporating combinations of such capabilities.

[0073] Having thus presented one technical context that is suitable but not limiting for the implementation of exemplary embodiments of the present invention, we will now describe the exemplary embodiments in more detail.

[0074] Figure 2 is a flowchart of signal transmission and logic for the feedback and use of channel state information. This figure further illustrates the operation of one or more exemplary methods, the results of executing computer program instructions embodied in computer-readable memory, functions performed by logic implemented in hardware, and / or the operation of interconnecting means for performing functions according to exemplary embodiments. For example, the control module 140 for UE110 and the control module 150 for RAN node 170 may include multiple blocks of the block in Figure 2, each included block being an interconnecting means for performing functions within the block. The block in Figure 2 is assumed to be executed, for example, by UE110 under the control of control module 140, or, for example, by RAN node 170 under the control of control module 150, at least partially.

[0075] In step 1, the RAN node 170 sends a reference signal to the UE 110. In step 2, the UE uses the reference signal to determine channel status information (CSI) (including PMI). In step 3, the UE 110 uses the determined channel status information to determine feedback information (including PMI). In step 4, the UE 110 provides feedback with the determined feedback information (including PMI). This information is typically provided using another CSI report 210.

[0076] In response to receiving feedback information, the RAN node 170 determines in step 5 to use precoding (e.g., one or more matrices) based on at least the PMI. In step 6, the RAN node 170 applies the determined precoding to the data it intends to send to the UE, and in step 7, it sends the precoded data to the UE. In step 8, the UE 110 processes the received precoded data.

[0077] Note that in other parts of this disclosure, RAN node 170 will be referred to as gNB. As stated above, this is not limiting, and RAN node 170 may be other elements such as eNB.

[0078] Figure 2 provides a simplified overview of the reporting and use of channel status information, such as PMI. Exemplary embodiments described herein relate to the determination and reporting of PMI. First, the technical domain of PMI determination and reporting is introduced, followed by a detailed description of the overview and exemplary embodiments.

[0079] First, in the Rel-16 type II precoder matrix indicator (PMI) feedback, a new codebook for compressing channel state information (CSI) over several (N3) PMI sub-bands has been introduced, where each sub-band has a PMI determined for it. A subset M of the N3 elements (where M < N3) is selected from this frequency domain (FD) codebook to form a basis of orthogonal vectors, which is signaled from UE110 to gNB170 as part of the CSI report 210. Each codebook element is indicated by an index of the alphabet set {0, 1, ···, N3 - 1}. Here, N3 is the size of the codebook and corresponds to the number of PMI sub-bands. In an exemplary embodiment, the FD basis subset, which is the index of the M basis vectors, is reported from UE110 to gNB170.

[0080] In RAN1#97, for a large number of PMI sub-bands such as N3 > 19, a sliding window mechanism has been introduced to simplify the signaling of this FD basis subset. See the agreement on the FD basis subset selection scheme in section 7.2.8.1 "CSI enhancement for MU-MIMO support" of 3GPP "RAN1 Chairman’s Notes RAN1#97", Reno, USA, May 2019. This window is applied to the codebook index such that only the indices within the window can be reported. This operation limits the alphabet set of the codebook indices that can be reported from N3 to the possible values of L corresponding to a window of size L. In an example, L = 2M. The sliding window is parameterized by M initial which is signaled as part of the CSI report 310.

[0081] Also, for the FD basis subset, when N3 > 19, assuming L = 2M and the first element is always 0 (zero), the bit width

Number

[0082] Regarding the exemplary problem, the M combinations of frequency-domain (FD) components for layers l=1,···,υ are expressed in vector form of their indices.

number

number

[0083] This M codebook vector is index i l This is shown by (l=1,···,υ). However,

number

[0084] Note that the example in equation (3) is just one example, and it applies to the cases where N3 > 19 and L = 2M.

[0085] In this case, n 3,l The codebook index is the FD component associated with the strongest coefficient.

number

number

number

number

number

[0086] Generally, i l This is a combination index of degree M-1 and degree 2M-1, and when N3 is large, for example, when N3 > 19 in a particular exemplary embodiment, it is possible to map (M-1) combinations to a set of elements up to 2M-1. Codebook elements

number

[0087] Thus, IntS is a new restricted set of codebook elements, and the reported elements [Number] , where f = 1, 2, ··· M - 1 can take any value within an alphabet of size 2M - 1 (the zero value is always within the window but may not be reported). The values in the set change with parameter M initial . Note that some selected values may fall outside the range {1, 2, ···, 2M - 1}. This will be explained in more detail by referring to FIG. 4 described later.

[0088] To solve this problem, in the exemplary embodiments of the present specification, a mapping function [Number] <00**********9>is introduced. [Number] The notation means that the value "0" is excluded from the set IntS. For example, a mapping function is introduced that enables the (M - 1) combinations of non-zero elements of the intermediate set IntS identified by a sliding window of length 2M for a set of size N3 > 2M to be indicated by a combination index of order M - 1 and number 2M - 1. Without this mapping, a larger combination index of number N3 - 1 would have to be used, and this combination index <00**********6>[Number] instead of [Number] corresponds to a larger index bit width.

[0089] More specifically, this element [Number] elements

number

number

number

[0090] Another alternative equivalence is given as follows:

number

[0091] This operation sets the value IntS to M initial This changes accordingly, allowing mapping to a consecutive 2M value set {0, 1, 2, ..., 2M-1}. After applying this map, (M-1) combinations

number

number

number

number

number

[0092] number sequence

number

number

number

[0093] After defining the ranking function in equation (10), the unranking procedure is straightforward and follows the standard algorithm for index i l from sequence

number

number

[0094] Specifically, the inverse equation of equation (6), (7), or (8) is:

number

[0095] The inverse equation of equation (9) is,

number

[0096] Figure 3 shows the uplink control information (UCI) associated with an extended Type II PMI (Precoder Matrix Index) report for layer l. In this figure, the following acronyms are used and defined: SD: spatial domain, SCI: strongest coefficient index, RA: reference amplitude, and NZC: non-zero coefficient. The PMI report 300 in this example includes a fixed-size first part (part 1) 305 and a variable-size second part (part 2) 310. The PMI report 300 may be part of a CSI report 210 sent in step 4 of Figure 2, for example. The variable-size part 310 includes three groups, group 0, group 1, and group 2. Group 0 includes the SD rotation, SD basis, and SCI index. Group 1 includes the FD basis, RA, bitmap, and NZC index. Group 2 includes the bitmap and NZC index.

[0097] The index of the frequency domain (FD) basis is index i. l And, parameter M initial Additional indicator i init Includes 325. In certain embodiments, an additional index i init 325 is used for many PMI subbands, e.g., N3>19, but this is not limited to them. Codebook element

number

[0098] Figure 4 shows a sliding window mechanism using FD codebook indices (0-21) in the frequency domain, with size L=2M=14 and initial point M initialAn example diagram is shown with the corresponding mapping using a window of =-6. More specifically, Figure 4 is an explanatory diagram of the sliding window mechanism applied to the FD basis representation and the remapping of values ​​within the window, using the following example values: N3=22, M=7, and M initial = -6. The window wraps, so M initial If it is negative, the window is -M initial Note that by sliding only to the left, the window will consist of two parts (parts 405 and 410 or 415 and 420) located at both ends of an interval of length N3, as shown in Figure 4. Also, as mentioned above, for an alphabet of size 2M-1 (zero values ​​are always within the window but may not need to be reported), the values ​​in the set are parameter M initial Please note that this will change, and some selected values ​​may fall outside the range {1, 2, ..., 2M-1}. In Figure 4, M initial If <0, then multiple values ​​exist outside the range associated with parts 405 and 408 in Layer 1, or parts 415 and 418 in Layer 2. Conversely, M initial When = 0, the window corresponds to the dashed line in Figure 4 and is the selected element.

number

[0099] The configuration in Figure 4 is υ = 2 layers. Index i init The window parameter M is shown by initial While the FD base subset of size M is common to all layers, the FD base subset of size M is layer-specific. In layer 1, the FD component selected within the window is...

number

number

number

number

[0100] In the above example, the mapping operation results in the set of values ​​IntS being M initial It was stated that this changes accordingly, making it possible to map to a continuous set of 2M values ​​{0, 1, 2, ..., 2M-1}. Figure 4 is an explanatory diagram of this concept. initial Regardless of the value of, the set of values ​​IntS maps to a contiguous set of 2M indices (for example, 0 to 13 in this case) and their corresponding FD components.

[0101] The above example can also be used to clarify the following: Before remapping in equation (8), the (M-1) combination (excluding the zeroth element) for the first layer is:

number

number

number

number

number

[0102] Figure 5 shows the FD base subset when the sliding window mechanism is applied.

number

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[0103] In block 510, the FD basis is the following subset

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[0104] Referring to Figure 6, this figure is a flowchart of the method performed by network nodes for mapping combined indices to a windowed FD basis for PMI reporting and use. This figure illustrates the operation of one or more exemplary methods, the results of executing computer program instructions embodied in computer-readable memory, functions performed by hardware-implemented logic, and / or the operation of interconnection means for performing functions according to exemplary embodiments. The blocks in Figure 6 are performed by RAN node 170 and network (e.g., access) nodes such as gNB in ​​particular. The description of Figure 6 assumes that gNB is used, but this is an example of a network node.

[0105] In block 610, gNB170 is PMI report and combined index i l A CSI report containing the following is received. gNB170, in block 620, is a strictly decreasing sequence.

number

number

number

[0106] In block 640, gNB170 performs an invert of the mapping from block 520. For example, a sequence

number

number

[0107] Without limiting the scope, interpretation, or application of the claims described below, the technical effects of one or more of the exemplary embodiments disclosed herein are as follows: the value in the set is parameter M initial The challenge is to address the fact that this changes, and some selection values ​​may fall outside the range {1, 2, ..., 2M-1}. Another technical effect of one or more embodiments of the exemplary embodiments disclosed herein is that

number

number

[0108] When used in this application, the term "circuit" may mean one or more or all of the following:

[0109] In other words, (a) hardware-only circuit implementation (such as implementation of analog and / or digital circuits only).

[0110] and (b) combinations of hardware circuits and software, for example (where applicable), (i) combinations of analog and / or digital hardware circuits(s) and software / firmware, and (ii) combinations of any part of a hardware processor(s) and software (including digital signal processors(s), software, and memory(s) that work together to cause a device such as a mobile phone or server to perform various functions).

[0111] (c) Hardware circuits and / or processors, such as a microprocessor(s) or part of a microprocessor(s), which require software (e.g., firmware) for operation but may not be present when not required for operation.

[0112] This definition of "circuit" applies to all uses of the term in this application, including its use in any claim. Further examples include, as used in this application, a hardware circuit or processor (or more processors), or a portion of a hardware circuit or processor, as well as an embodiment of the software and / or firmware associated therewith. The term "circuit" also includes, for example, a baseband integrated circuit or processor integrated circuit for a mobile device, or a similar integrated circuit in a server, cellular network device, or other computing or network device, where applicable to the elements of a particular claim.

[0113] Embodiments of this specification may be implemented in software (executed by one or more processors), hardware (e.g., application-specific integrated circuits), or a combination of software and hardware. In exemplary embodiments, the software (e.g., application logic, instruction sets) is held in one of a variety of conventional computer-readable media. In the context of this document, “computer-readable media” may be any medium or means capable of storing, saving, communicating, propagating, or carrying instructions for use by or in connection with instruction execution systems, apparatus, or devices such as computers, for example, an example of a computer is described and depicted in Figure 1. Computer-readable media may include computer-readable storage media (e.g., memory 125, 155, 171 or other devices) which may be any medium or means capable of storing, saving, and / or carrying instructions for use by or in connection with instruction execution systems, apparatus, or devices such as computers. Computer-readable storage media do not contain propagating signals.

[0114] Where necessary, the different functions discussed herein may be performed in different orders and / or simultaneously with each other. Furthermore, where necessary, one or more of the above functions may be optional or in combination.

[0115] While various aspects of the present invention are described in the independent claims, other aspects of the present invention include not only the combinations expressly described in the claims, but also other combinations of the features of the described embodiments and / or dependent claims with the features of the independent claims.

[0116] While the above describes exemplary embodiments of the present invention, it should be noted that these descriptions should not be taken as limiting. Rather, several modifications and alterations can be made without departing from the scope of the invention as defined in the appended claims.

Claims

1. It is a method, The process includes determining the precoding matrix index using user equipment, and determining the precoding matrix index is Determining an intermediate set of vectors from a frequency domain codebook, wherein determining the intermediate set of vectors is The intermediate set of the aforementioned vectors is set to initial value (M initial ) to be selected based on the above M initial The value is selected from a set of non-positive values ​​{-2M+1, -2M+2, ..., 0}, and the intermediate set of the vector contains a 2M vector, and the index of the intermediate set of the vector is IntS = {(M initial +i) mod N 3 Defined as {i = 0, 1, ..., 2M-1}, N 3 is the size of the frequency domain codebook of the vector, including the selection, Determining the intermediate set of the aforementioned vectors, Forming a subset of the intermediate set of the vectors, further, This includes selecting the subset of M vectors from the intermediate set of 2M vectors. To form a subset of the intermediate set of the aforementioned vectors, Mapping the subset of M vectors to a combination index, wherein mapping the subset of M vectors to the combination index is Non-zero indices of the M vector in the aforementioned intermediate set Apply the first map to the first intermediate index defined between 1 and 2M-1. Obtaining the first map is done by the following function Accordingly, the non-zero index of the M vector in the intermediate set This includes dividing the intermediate set into a first group and a second group according to the initial value of the intermediate set, and subtracting a first pre-set amount from the index of the second group, This is the non-zero index of the M vector for layer l for f = 1, 2, ..., M-1, and the The non-zero values ​​are the set of values ​​{1, 2, ..., N} associated with the vector in the frequency domain codebook. 3 Applying the first map selected from {-1}, The first intermediate index Apply the second map to the second intermediate index defined between zero and 2M-2. The process involves obtaining the first intermediate index for f = 1, 2, ..., M-1, and applying the second map. , second intermediate index For and for layer l, the following function Accordingly, the first intermediate index Applying the second map, which includes inverting the sign of and adding a second preset amount, The second intermediate index The combination coefficient The aforementioned combination index is used as an argument in the calculation of Calculating the following function, and using the second intermediate index as an argument in the calculation of the combination coefficient to calculate the combination index is: Here, Accordingly, the second intermediate index is used as the first argument of the combination coefficient, and the non-zero index The calculation of the aforementioned combination index associated with the vector, including the use of the Mapping the aforementioned subset of M vectors to a combinatorial index, The precoding matrix index is at least the combination index and the index of the initial value (M initial) Formed from, the precoding matrix index is the combination index and the index of the initial value (M initial) To include, Methods that include...

2. The aforementioned non-zero index A vector having the index of the initial value (M initial) and the aforementioned combined index The method according to claim 1, as identified by and

3. The method according to claim 1, further comprising transmitting the precoding matrix index to the RAN node using the user device.

4. The method according to claim 3, wherein determining the precoding matrix index includes using a reference signal obtained from the RAN node.

5. The method according to claim 1, wherein the initial value of the intermediate set is common to all reported layers, whereas the combination index is specific to each reported layer.

6. The method according to claim 3, further comprising receiving the data having one or more codebook elements applied to the data based on the transmitted precoding matrix index by the user device and from the RAN node.

7. It is a method, The base station receives a precoding matrix index from user equipment, wherein the precoding matrix index is a combination index that maps to a subset of vectors from a frequency domain codebook. Including the aforementioned receiving, Using at least the received precoding matrix index, determine information to apply to the data to be transmitted to the user device from at least the frequency domain codebook, Includes, The above decision is, Obtaining a first intermediate index and a second intermediate index, wherein the second intermediate index for layer l for f = 1, 2, ..., M-1 However, the aforementioned combination index Obtained by performing a deranking procedure on it, The first intermediate index for layer l for f = 1, 2, ..., M-1 However, the following function By inverting them, the second intermediate index of each of them Obtained from, To obtain the above, The following function By inverting them, the first intermediate index of each of them Therefore, for f = 1, 2, ..., M-1, the non-zero index of the vector with respect to layer l. To obtain, Includes, The aforementioned However, the vector in the frequency domain codebook is associated with the precoding matrix index, and the index of the initial value (M initial) is the index of the precoding matrix. The above M initial is an index of the initial value (M initial) Obtained from, method.

8. The above determination is at least the non-zero index for layer l for f = 1, 2, ..., M-1. The method of claim 7, comprising obtaining precoding weights to be applied to the data to be transmitted to the user device from the vector of the frequency domain codebook corresponding to the

9. The method according to claim 7, further comprising transmitting the data to the user device, to which at least the information from the frequency domain codebook has been applied, by the base station.

10. A computer program, the computer program comprising code for performing any of the methods of claims 1 to 9 when the computer program is executed on a computer.

11. It is a device, One or more processors, One or more memory locations containing computer program code, Equipped with, The one or more memory and the computer program code, together with the one or more processors, in the device, The system is configured to allow the user device to determine the precoding matrix index, and the determination of the precoding matrix index is Determining an intermediate set of vectors from a frequency domain codebook, wherein determining the intermediate set of vectors is Selecting the intermediate set of the vectors based on an initial value (M initial ), where the M initial is selected from a set of non-positive values {-2M + 1, -2M + 2,..., 0}, there are 2M vectors in the intermediate set of the vectors, and the index of the intermediate set of the vectors is IntS = {(M initial + i) mod N 3 , i = 0, 1,..., 2M - 1}, where N 3 is the size of the frequency domain codebook of the vectors, including the said selecting Determining the intermediate set of the aforementioned vectors, Forming a subset of the intermediate set of the vectors, further, This includes selecting the subset of M vectors from the intermediate set of 2M vectors. To form a subset of the intermediate set of the aforementioned vectors, Mapping a subset of the aforementioned vectors to a combination index, wherein mapping a subset of the aforementioned vectors to a combination index is Non-zero indices of the M vector in the aforementioned intermediate set Apply the first map to the first intermediate index defined between 1 and 2M-1. Obtaining the first map is done by the following function Accordingly, the non-zero index of the M vector in the intermediate set This includes dividing the intermediate set into a first group and a second group according to the initial value of the intermediate set, and subtracting a first pre-set amount from the index of the second group, This is the non-zero index of the M vector for layer l for f = 1, 2, ..., M-1, and the The non-zero values ​​are the set of values ​​{1, 2, ..., N} associated with the vector in the frequency domain codebook. 3 Applying the first map selected from {-1}, The first intermediate index Apply the second map to the second intermediate index defined between zero and 2M-2. The process involves obtaining the first intermediate index for f = 1, 2, ..., M-1, and applying the second map. , second intermediate index For and for layer l, the following function Accordingly, the first intermediate index Applying the second map, which includes inverting the sign of and adding a second preset amount, The second intermediate index The combination coefficient The aforementioned combination index is used as an argument in the calculation of Calculating the following function, and using the second intermediate index as an argument in the calculation of the combination coefficient to calculate the combination index is: Here, Accordingly, the second intermediate index is used as the first argument of the combination coefficient, and the non-zero index The calculation of the aforementioned combination index associated with the vector, including the use of the Mapping a subset of the aforementioned vectors to a combination index, The precoding matrix index is at least the combination index and the index of the initial value (M initial) Formed from, the precoding matrix index is the combination index and the index of the initial value (M initial) To include, including, Device.

12. The aforementioned non-zero index A vector having the index of the initial value (M initial) and the aforementioned combined index The apparatus according to claim 11, identified by and

13. The apparatus according to claim 11, wherein the one or more memory and the computer program code are further configured together with the one or more processors to cause the apparatus to transmit the precoding matrix index to the RAN node via the user device.

14. The apparatus according to claim 13, wherein determining the precoding matrix index includes using a reference signal obtained from the RAN node.

15. The apparatus according to claim 11, wherein the initial value of the intermediate set is common to all reported layers, whereas the combination index is specific to each reported layer.

16. The apparatus according to claim 13, wherein the one or more memories and the computer program code are further configured together with the one or more processors to cause the apparatus to receive the data having one or more codebook elements applied to the data based on the transmitted precoding matrix index, from the user equipment and from the RAN node.

17. It is a device, One or more processors, One or more memory locations containing computer program code, Equipped with, The one or more memory and the computer program code, together with the one or more processors, in the device, The base station receives a precoding matrix index from user equipment, wherein the precoding matrix index is a combination index that maps to a subset of vectors from a frequency domain codebook. Including the aforementioned receiving, Using at least the received precoding matrix index, determine information to apply to the data to be transmitted to the user device from at least the frequency domain codebook, wherein the determination is: Obtaining a first intermediate index and a second intermediate index, wherein the second intermediate index for layer l for f = 1, 2, ..., M-1 However, the aforementioned combination index Obtained by performing a deranking procedure on it, The first intermediate index for layer l for f = 1, 2, ..., M-1 However, the following function By inverting them, the second intermediate index of each of them Obtained from, the acquisition of, The following function By inverting them, the first intermediate index of each of them Therefore, for f = 1, 2, ..., M-1, the non-zero index of the vector with respect to layer l. To obtain, Including the determination of the above, It is configured to perform the following actions: The aforementioned However, the vector in the frequency domain codebook is associated with the precoding matrix index, and the index of the initial value (M initial) is the index of the precoding matrix. The above M initial is an index of the initial value (M initial) Obtained from, Device.

18. When making a decision, the one or more memory and the computer program code, together with the one or more processors, provide the device with at least the non-zero index for layer l for f = 1, 2, ..., M-1. The apparatus according to claim 17, configured to obtain precoding weights to be applied to the data to be transmitted to the user device from the vectors of the frequency domain codebook corresponding to the

19. The apparatus according to claim 17, wherein the one or more memories and the computer program code are further configured together with the one or more processors to cause the apparatus to transmit, by the base station, the data to which at least the information from the frequency domain codebook has been applied, to the user equipment.

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