Codebook design for 8TX UE with four coherent antenna groups

Abstract

Methods and apparatus for an 8TX UE with four coherent antenna groups are disclosed. In one embodiment, a UE includes a transceiver; and a processor coupled to the transceiver, where the processor is configured to receive, via the transceiver, a control message that schedules a PUSCH transmission with a transmission rank N to be transmitted by eight antenna ports of the four coherent antenna groups, where the control message includes a TPMI indicating an 8TX precoding matrix used by the four coherent antenna groups, n is any one of 1 to 8; and transmitting, via the transceiver, the scheduled PUSCH transmission according to the control message.

Description

Technical Field

[0001] The subject matter disclosed herein generally relates to wireless communication and, more particularly, to methods and apparatus for a codebook for an 8TX UE (UE with 8 antenna ports) having four coherent antenna groups. Background Art

[0002] For advanced UEs equipped with 8 antennas having one or more layers, physical uplink shared channel (PUSCH) (8TX PUSCH) transmissions with 8 antenna ports are supported in New Radio (NR) Release 18.

[0003] The present disclosure is directed to a codebook for an 8TX user equipment (UE) having four coherent antenna groups. Summary of the Invention

[0004] Methods and apparatus for an 8TX user equipment (UE) having four coherent antenna groups are disclosed.

[0005] In one embodiment, the UE includes a transceiver; and a processor coupled to the transceiver, wherein the processor is configured to receive, via the transceiver, a control message that schedules a PUSCH transmission with a transmission rank N to be sent by eight antenna ports in four coherent antenna groups, wherein the control message includes a TPMI indicating an 8TX precoding matrix used by the four coherent antenna groups, and wherein N is any one of 1 to 8; and to send, via the transceiver, the scheduled PUSCH transmission in accordance with the control message.

[0006] In some embodiments, the four coherent antenna groups are divided into two antenna group pairs, each antenna group pair consisting of two coherent antenna groups, and the TMPI indicates one or two 4TX partial precoding matrices, each 4TX partial precoding matrix being used by one of the two antenna group pairs.

[0007] In some embodiments, each 4TX partial interference precoding matrix is split into two 2TX precoding matrices, and each 2TX precoding matrix is used as the precoding matrix for one of the two coherent antenna groups in an antenna group pair using the 4TX partial interference precoding matrix. If the transmission rank is 1, one 4TX partial interference precoding matrix is a 4TX rank-1 precoding matrix and is used by an antenna group pair indicated by the TPMI. If the transmission rank is 2, both 4TX partial interference precoding matrices are 4TX rank-1 precoding matrices. If the transmission rank is 3, one of the two 4TX partial interference precoding matrices is a 4TX rank-1 precoding matrix and the other of the two 4TX partial interference precoding matrices is a 4TX rank-2 precoding matrix. If the transmission rank is 4, both 4TX partial interference precoding matrices are 4TX rank-2 precoding matrices. If the transmission rank is 5, one of the two 4TX partial interference precoding matrices is a 4TX rank-2 precoding matrix and the other of the two 4TX partial interference precoding matrices is a 4TX rank-3 precoding matrix. If the transmission rank is 6, both 4TX partial interference precoding matrices are 4TX rank-3 precoding matrices. If the transmission rank is 7, one of the two 4TX partial interference precoding matrices is a 4TX rank-3 precoding matrix and the other of the two 4TX partial interference precoding matrices is a 4TX rank-4 precoding matrix. If the transmission rank is 8, both 4TX partial interference precoding matrices are 4TX rank-4 precoding matrices.

[0008] In some embodiments, each 4TX partial interference precoding matrix is selected from all 4TX partial interference precoding matrices of an appropriate rank.

[0009] In some embodiments, at least one of the two partial interference precoding matrices is selected only from a part of the 4TX partial interference precoding matrices of an appropriate rank. Specifically, the 2TX precoding matrix of each coherent antenna group is different from the 2TX precoding matrix of any other coherent antenna group.

[0010] In some embodiments, the TPMI includes a single indication of a combination of one 4TX partial interference precoding matrix or two 4TX partial interference precoding matrices.

[0011] Alternatively, the TPMI includes a first part indicating one of the two 4TX partial interference coding matrices and a second part indicating the other of the two 4TX partial interference coding matrices. Specifically, the second part indicates the other of the two 4TX partial interference coding matrices from a subset of precoding matrices of an appropriate rank based on the indication of one of the two 4TX partial interference coding matrices by the first part; or the first part indicates one of the two 4TX partial interference coding matrices from a subset of precoding matrices of an appropriate rank based on the indication of the other of the two 4TX partial interference coding matrices by the second part.

[0012] In some embodiments, depending on the antenna port number, each of the two split 2TX precoding matrices is applied to a coherent antenna group including two antenna ports.

[0013] In some embodiments, the TPMI indicates a combination of a coherent antenna group and a 2TX rank-1 full-phase precoding matrix. If the transmission rank is 1, the TMPI indicates one of the four coherent antenna groups and a 2TX rank-1 full-phase precoding matrix. If the transmission rank is 2, the TMPI indicates a combination of two of the four coherent antenna groups and a combination of two 2TX rank-1 full-phase precoding matrices. If the transmission rank is 3, the TMPI indicates a combination of three of the four coherent antenna groups and a combination of three 2TX rank-1 full-phase precoding matrices. If the transmission rank is 4, the 8TX rank-4 precoding matrix consists of four 2TX rank-1 full-phase precoding matrices, where the four 2TX rank-1 full-phase precoding matrices are applied to the four coherent antenna groups in a sequential manner. If the transmission rank is 5, the TPMI indicates which one of the third and fourth coherent antenna groups with a 2TX rank-1 full-phase precoding matrix added and which one of the four 2TX rank-1 full-phase precoding matrices is the added 2TX rank-1 full-phase precoding matrix. If the transmission rank is 6, the TPMI indicates which one of the first and second coherent antenna groups with the first 2TX rank-1 full-phase precoding matrix added and which one of the third and fourth coherent antenna groups with the second 2TX rank-1 full-phase precoding matrix added, and which one of the four 2TX rank-1 full-phase precoding matrices is the added first 2TX rank-1 full-phase precoding matrix and which one of the four 2TX rank-1 full-phase precoding matrices is the added second 2TX rank-1 full-phase precoding matrix. If the transmission rank is 7, the TPMI indicates which one of the first and second coherent antenna groups with the first 2TX rank-1 full-phase precoding matrix added, and which one of the four 2TX rank-1 full-phase precoding matrices is the added first 2TX rank-1 full-phase precoding matrix, which one of the four 2TX rank-1 full-phase precoding matrices is the second 2TX rank-1 full-phase precoding matrix added to the third coherent antenna group, and which one of the four 2TX rank-1 full-phase precoding matrices is the third 2TX rank-1 full-phase precoding matrix added to the fourth coherent antenna group. If the transmission rank is 8, the TPMI indicates which one of the four 2TX rank-1 full-phase precoding matrices is the first 2TX rank-1 full-phase precoding matrix added to the first coherent antenna group, which one of the four 2TX rank-1 full-phase precoding matrices is the second 2TX rank-1 full-phase precoding matrix added to the second coherent antenna group, which one of the four 2TX rank-1 full-phase precoding matrices is the third 2TX rank-1 full-phase precoding matrix added to the third coherent antenna group, and which one of the four 2TX rank-1 full-phase precoding matrices is the fourth 2TX rank-1 full-phase precoding matrix added to the fourth coherent antenna group.Specifically, each added 2TX rank-1 full-phase interference coding matrix is different from the 2TX rank-1 full-phase interference coding matrix initially applied to the coherent antenna group to which the added 2TX rank-1 full-phase interference coding matrix is added in the 8TX rank-4 precoding matrix; and if there are two, three, or four added 2TX rank-1 full-phase interference coding matrices, each of the two, three, or four added 2TX rank-1 full-phase interference coding matrices is different.

[0014] In some embodiments, if the transmission rank is r which is greater than 4, the TPMI indicates r - 4 2TX rank-1 full-phase interference coding matrices, and each 2TX rank-1 full-phase interference coding matrix is added to one of the r - 4 antenna groups based on the 8TX rank-4 precoding matrix. If r is 5, one 2TX rank-1 full-phase interference coding matrix is added to the third antenna group or the fourth antenna group. If r is 7, one 2TX rank-1 full-phase interference coding matrix is added to the first antenna group or the second antenna group, and two 2TX rank-1 full-phase interference coding matrices are added to the third antenna group and the fourth antenna group. Each antenna group with one added 2TX rank-1 full-phase interference coding matrix transmits two data layers.

[0015] In another embodiment, a method performed at a UE includes: receiving a control message that schedules a PUSCH transmission with a transmission rank N to be sent by eight antenna ports in four coherent antenna groups, where the control message includes a TPMI indicating an 8TX precoding matrix used by the four coherent antenna groups, and where N is any one of 1 to 8; and sending the scheduled PUSCH transmission according to the control message.

[0016] In yet another embodiment, a base station unit includes a transceiver; and a processor coupled to the transceiver, where the processor is configured to send, via the transceiver, a control message that schedules a PUSCH transmission with a transmission rank N to be sent by eight antenna ports in four coherent antenna groups, where the control message includes a TPMI indicating an 8TX precoding matrix used by the four coherent antenna groups, and where N is any one of 1 to 8; and receive, via the transceiver, the scheduled PUSCH transmission sent according to the control message.

[0017] In still another embodiment, a method performed at a base station unit includes: sending a control message that schedules a PUSCH transmission with a transmission rank N to be sent by eight antenna ports in four coherent antenna groups, where the control message includes a TPMI indicating an 8TX precoding matrix used by the four coherent antenna groups, where N is any one of 1 to 8; and receiving the scheduled PUSCH transmission sent according to the control message. Description of the Drawings

[0018] A more specific description of the embodiments briefly described above will be presented with reference to the specific embodiments illustrated in the accompanying drawings. These embodiments will be described and explained with additional specificity and detail by using the drawings, understanding that the drawings depict only some embodiments and should not be considered as limiting the scope, in the drawings:

[0019] Figure 1 Illustrate several antenna layouts with different numbers of antenna groups;

[0020] Figure 2(a) and 2(b) Illustrate the first antenna port numbering;

[0021] Figure 3(a) and 3(b) Illustrate the second antenna port numbering;

[0022] Figure 4(a) and 4(b) Illustrate the third antenna port numbering;

[0023] Figure 5(a) and 5(b) Illustrate the fourth antenna port numbering;

[0024] Figure 6 Is a schematic flowchart illustrating an embodiment of a method;

[0025] Figure 7 Is a schematic flowchart illustrating an embodiment of another method; and

[0026] Figure 8 Is a schematic block diagram illustrating a device according to an embodiment. Detailed Description

[0027] As will be understood by those skilled in the art, certain aspects of the embodiments may be embodied as a system, apparatus, method, or program product. Accordingly, the embodiments may take the form of an entirely hardware embodiment, an entirely software embodiment (including firmware, resident software, microcode, etc.), or an embodiment combining software and hardware aspects, all of which are generally referred to herein as "circuits," "modules," or "systems." In addition, the embodiments may take the form of a program product embodied in one or more computer-readable storage devices storing machine-readable code, computer-readable code, and / or program code (hereinafter referred to as "code"). The storage device may be tangible, non-transitory, and / or non-transmissive. The storage device may not contain a signal. In certain embodiments, the storage device only uses a signal for accessing the code.

[0028] Certain functional units described in this specification may be marked as modules to emphasize their independent implementation more particularly. For example, a module may be implemented as a hardware circuit, which includes custom very large scale integration ("VLSI") circuits or gate arrays, off-the-shelf semiconductors such as logic chips, transistors, or other discrete components. A module may also be implemented in a programmable hardware device, such as a field programmable gate array, programmable array logic, programmable logic device, etc.

[0029] A module may also be implemented with code and / or software for execution by various types of processors. The identified code module may include, for example, one or more physical or logical blocks of executable code, which may be organized, for example, as objects, procedures, or functions. However, the executable programs of the identified modules do not need to be physically located together, but may include different instructions stored in different locations, which, when logically connected together, include the module and implement the stated purpose of the module.

[0030] In fact, a module of code may contain a single instruction or multiple instructions and may even be distributed over several different code segments, different programs, and across several storage devices. Similarly, the operational data may be identified and illustrated herein within the module and may be embodied in any suitable form and organized within any suitable type of data structure. The operational data may be collected as a single data set or may be distributed over different locations, including distributed over different computer-readable storage devices. In cases where a module or a portion of a module is implemented in software, the software portion is stored on one or more computer-readable storage devices.

[0031] Any combination of one or more computer-readable media may be used. The computer-readable media may be a computer-readable storage medium. The computer-readable storage medium may be a storage device that stores the code. The storage device may be, for example but not necessarily, an electronic, magnetic, optical, electromagnetic, infrared, holographic, micro-mechanical, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing.

[0032] A non-exhaustive list of more specific examples of storage devices includes the following: an electrical connection having one or more wires, a portable computer disk, a hard disk, a random access memory ("RAM"), a read-only memory ("ROM"), an erasable programmable read-only memory ("EPROM") or flash memory, a portable compact disc read-only memory ("CD-ROM"), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing. In the context of this document, a computer-readable storage medium may be any tangible medium that can contain or store a program for use by or in connection with an instruction execution system, apparatus, or device.

[0033] The code for performing the operations of the embodiments can include any number of lines and can be written in any combination of one or more programming languages, including: object-oriented programming languages such as Python, Ruby, Java, Smalltalk, C++; and traditional procedural programming languages such as the "C" programming language; and / or machine languages such as assembly language. The code can be executed entirely on the user's computer, partially on the user's computer, executed as a stand-alone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In the last scenario, the remote computer can be connected to the user's computer through any type of network including a local area network (LAN) or a wide area network (WAN), or a connection to an external computer can be established (e.g., using an Internet service provider over the Internet).

[0034] References to "one embodiment", "an embodiment", or similar language throughout this specification mean that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, appearances of the phrases "in one embodiment", "in an embodiment", and similar language throughout this specification may, but do not necessarily, all refer to the same embodiment, but rather mean "one or more but not all embodiments". Unless otherwise explicitly specified, the terms "comprises", "comprising", "has", and their variants mean "including but not limited to". Unless otherwise explicitly specified, a list of enumerated items does not imply that any or all of the items are mutually exclusive. Unless otherwise explicitly specified, the terms "a", "an", and "the" also refer to "one or more".

[0035] Furthermore, the features, structures, or characteristics of the various embodiments described can be combined in any suitable manner. In the following description, numerous specific details are provided, such as examples of programming, software modules, user selections, network transactions, database queries, database structures, hardware modules, hardware circuits, hardware chips, etc., to provide a thorough understanding of the embodiments. However, those skilled in the relevant art will recognize that the embodiments can be practiced without one or more of the specific details, or with other methods, components, materials, etc. In other instances, well-known structures, materials, or operations are not shown or described in detail to avoid obscuring any aspect of the embodiments.

[0036] Aspects of different embodiments are described below with reference to schematic flowcharts and / or schematic block diagrams of methods, apparatuses, systems, and program products according to embodiments. It will be understood that each block of the schematic flowcharts and / or schematic block diagrams, and combinations of blocks in the schematic flowcharts and / or schematic block diagrams, can be implemented by code. This code can be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions executed via the processor of the computer or other programmable data processing apparatus create an apparatus for implementing the functions specified for one or more blocks in the schematic flowchart and / or schematic block diagram.

[0037] The code can also be stored in a storage device that can direct a computer, other programmable data processing apparatus, or other device to operate in a particular manner, such that the instructions stored in the storage device produce an article of manufacture that includes instructions for implementing the functions specified in one or more blocks of the schematic flowchart and / or schematic block diagram.

[0038] The code can also be loaded onto a computer, other programmable data processing apparatus, or other device to cause a series of operational steps to be performed on the computer, other programmable apparatus, or other device to produce a computer-implemented process, such that the code executed on the computer or other programmable apparatus provides a process for implementing the functions specified in one or more blocks of the flowchart and / or block diagram.

[0039] The schematic flowcharts and / or schematic block diagrams in the figures illustrate the architecture, functionality, and operation of possible implementations of apparatuses, systems, methods, and program products according to various embodiments. In this regard, each block in the schematic flowcharts and / or schematic block diagrams can represent a module, segment, or portion of code that includes one or more executable instructions for implementing the specified logical function.

[0040] It should also be noted that in some alternative implementations, the functions noted in the blocks may not occur in the order noted in the figures. For example, depending on the functions involved, two blocks shown in succession may be executed substantially simultaneously, or the blocks may sometimes be executed in the reverse order. Other steps and methods can be envisioned that are equivalent in function, logic, or effect to one or more blocks or portions thereof shown in the figures.

[0041] Although various arrow types and line types may be employed in flowcharts and / or block diagrams, they are not to be construed as limiting the scope of the corresponding embodiments. In fact, some arrows or other connectors may be used to merely indicate the logical flow of the depicted embodiments. For example, an arrow may indicate a waiting or monitoring period of unspecified duration between the recited steps of the depicted embodiments. It will also be noted that each block of the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, can be implemented by a special hardware-based system that performs the specified functions or actions, or by a combination of special hardware and code.

[0042] The description of the elements in each drawing may refer to the elements of the previous drawing. In all the drawings, the same numerals refer to the same elements, including alternative embodiments of the same element.

[0043] The UE can be configured for PUSCH multi-antenna precoding in two different modes, which are respectively referred to as codebook (CB)-based transmission and non-codebook (nCB)-based transmission. When the UE is configured for codebook-based PUSCH transmission, one sounding reference signal (SRS) resource set used for the codebook can be configured for the UE in a bandwidth part (BWP) of the cell. When the UE is configured for non-codebook-based PUSCH transmission, one SRS resource set used for the non-codebook can be configured for the UE in the BWP of the cell.

[0044] To enable codebook-based PUSCH transmission, the UE should be configured to transmit one or more SRS resources used for the codebook for uplink channel measurement. Based on the measurement of the configured SRS resources transmitted by the UE, the next-generation node B (gNB) determines a suitable transmission rank (hereinafter may be abbreviated as "rank") and precoding matrix from a predefined codebook that includes a set of precoding matrices with different ranks, and sends this information to the UE when scheduling PUSCH transmission.

[0045] When the UE is equipped with 8 antenna ports (e.g., PUSCH or SRS antenna ports), the base station unit (e.g., gNB) can send downlink control information (DCI) (e.g., DCI with format 0_1 or DCI with format 0_2) or radio resource control (RRC) messages (e.g., configuredGrantConfig) to the UE to configure the PUSCH with type 1 configured grant with up to 8 layers, for scheduling the dynamically scheduled PUSCH or the PUSCH with type 2 configured grant with up to 8 layers (i.e., PUSCH layers). The 8 antenna ports (e.g., PUSCH or SRS antenna ports) can be numbered as PUSCH or SRS antenna ports 1000, 1001, 1002, 1003, 1004, 1005, 1006, and 1007. Incidentally, a brief summary of the configured grant (CG) PUSCH is as follows. The CG PUSCH is used for semi-static uplink (UL) traffic and can be sent without dedicated scheduling DCI. Two types of CG PUSCH are specified in NR Release 15. For type 1 CG PUSCH, all the information used for PUSCH transmission is configured by RRC signaling, and the CG PUSCH can be sent periodically according to the configured period. For type 2 CG PUSCH, part of the information used for PUSCH transmission is configured by RRC signaling, while other information is indicated by the activating DCI. Type 2 CG PUSCH can only be sent periodically when the activating DCI is received. When the UE receives a deactivating DCI to deactivate type 2 CG PUSCH, the corresponding PUSCH shall not be sent. Both type 1 CG PUSCH and type 2 CG PUSCH are configured by the configured grant PUSCH (i.e., by the higher layer parameter configuredGrantConfig IE), and each configuredGrantConfig has an ID.

[0046] When transmitting the PUSCH layer from the UE, a precoding matrix is used in codebook-based PUSCH transmission to perform UL precoding on the modulated data. The UE shall perform UL precoding according to Equation 1.

[0047] Equation 1:

[0048]

[0049] where the block of the vector is the modulated data to be sent; W0 is the precoding matrix applied to the block of the vector; and the block of the vector is the precoded data that the UE is to send. v0 indicates the number of PUSCH layers or the rank of the PUSCH. P0 corresponds to PUSCH antenna port 1000, and P ρ-1Corresponding to PUSCH antenna port 1000 + ρ - 1. In the present invention, ρ = 8.

[0050] Coherent transmission is described as follows:

[0051] If the UE reports the ability of full coherence and 8 antenna ports (i.e., PUSCH antenna ports 1000, 1001, 1002, 1003, 1004, 1005, 1006, and 1007), then all 8 PUSCH antenna ports can be used for coherent transmission of the PUSCH layer. For example, the precoding vector used for each layer can have 8 non-zero elements. For example, is an effective precoding vector for rank-1 PUSCH transmission with 8 fully coherent antenna ports. If the phase difference between any two antenna ports among multiple antenna ports is fixed, then the multiple antenna ports are coherent. If the phase difference between any two antenna ports among multiple antenna ports is not fixed, then the multiple antenna ports are non-coherent.

[0052] If the UE reports the ability of partial coherence or non-coherence with 8 antenna ports (i.e., PUSCH antenna ports 1000, 1001, 1002, 1003, 1004, 1005, 1006, and 1007), then only the coherent antenna ports (where the coherent antenna ports are part of the 8 antenna ports) can be used for the transmission of a PUSCH layer. Specifically, all 8 antenna ports are grouped into Ng antenna groups. All antenna ports within each antenna group are coherent, while antenna ports from different antenna groups are non-coherent. Figure 1 Illustrates several antenna layouts with different numbers of antenna groups.

[0053] In Figure 1 Ng represents the number of antenna groups. M represents the number of antennas in the vertical direction in the antenna group. N represents the number of antennas in the horizontal direction in the antenna group. P represents the number of polarizations of each antenna. Each polarization of the antenna corresponds to an antenna port.

[0054] Antenna layouts 1-a and 1-b correspond to fully coherent antenna arrays, i.e., all 8 antenna ports within each of antenna layouts 1-a and 1-b belong to one antenna group (e.g., antenna group #0, denoted as nNg = 0), and are coherent antenna ports.

[0055] Antenna layout 2-a and antenna layout 2-b correspond to a partially coherent antenna array with two antenna groups (Ng = 2). For example, in each of antenna layout 2-a and antenna layout 2-b, each of antenna group #0 (the first antenna group, denoted as nNg = 0) and antenna group #1 (the second antenna group, denoted as nNg = 1) includes four coherent antenna ports.

[0056] Antenna layout 3-a and antenna layout 3-b correspond to a partially coherent antenna array with four antenna groups (Ng = 4). For example, in each of antenna layout 3-a and antenna layout 3-b, each of antenna group #0 (the first antenna group, denoted as nNg = 0), antenna group #1 (the second antenna group, denoted as nNg = 1), antenna group #2 (the third antenna group, denoted as nNg = 2), and antenna group #3 (the fourth antenna group, denoted as nNg = 3) includes two coherent antenna ports.

[0057] Before discussing the codebook design, the UE needs to report its antenna layout, which includes the number of antenna groups (1 ≤ Ng ≤ 4), and optionally includes the antennas within each antenna group (M, N, P), where M indicates the number of antennas in the horizontal direction, N indicates the number of antennas in the vertical direction, and P indicates the number of polarizations of each antenna. One polarization of each antenna corresponds to an antenna port. Each antenna group has the same antenna structure.

[0058] The UE is able to report the supported maxRank ∈ {1, 2, 3, 4, 5, 6, 7, 8}, i.e., the maximum number of PUSCH layers for PUSCH transmission.

[0059] The gNB sends DCI to the UE to schedule one or more PUSCH transmissions. Depending on the reported maxRank, the rank of the scheduled PUSCH transmission can be 1, 2, 3, 4, 5, 6, 7, or 8. This means that the PUSCH transmission has L PUSCH layers, where L is equal to the rank, and the rank is less than or equal to maxRank. A precoding matrix (which can also be referred to as a precoder) should be determined for the scheduled PUSCH transmission.

[0060] Incidentally, the number of columns of the precoding matrix indicates the number of layers of PUSCH transmissions to which the precoding matrix can be applied. Thus, the precoding matrix (i.e., the precoder) can be further described as a rank-R precoding matrix (precoder), e.g., a rank-1 precoder, a rank-2 precoder, a rank-3 precoder, a rank-4 precoder, a rank-5 precoder, a rank-6 precoder, a rank-7 precoder, a rank-8 precoder. The rank-R precoding matrix (precoder) can also be denoted as an R-layer precoding matrix (precoder), e.g., a one-layer precoder (or single-layer precoder), a two-layer precoder, a three-layer precoder, a four-layer precoder, a five-layer precoder, a six-layer precoder, a seven-layer precoder, an eight-layer precoder. The number of rows of the precoding matrix (precoder) indicates the number of antenna ports to which the precoding matrix can be applied. For example, for a UE with 2 or 4 or 8 antenna ports, the precoding matrix (precoder) can have 2 or 4 or 8 rows (denoted as 2TX, 4TX, 8TX).

[0061] The present disclosure aims at a codebook for an 8TX UE (i.e., a UE with 8 antenna ports) having four coherent antenna groups (i.e., Ng = 4). When Ng = 4, the eight antenna ports are arranged in four antenna groups that are correlated, and each antenna group has 2 antenna ports. Each box represents a pair of coherently cross-polarized antennas. In the following description, "coherent antenna group" is abbreviated as "antenna group", and can also be referred to as "antenna port group" or "port group".

[0062] Before describing the embodiments, the antenna port numbering and the antenna group layout are described.

[0063] The 8TX UE has eight antenna ports in four antenna groups. The eight antenna ports are numbered from 0 to 7. The four antenna groups (or port groups) can be denoted as PG0, PG1, PG2, and PG3. Each antenna group includes antennas in two different polarization directions, where each antenna corresponds to one antenna port. As shown in Fig. 2(a) or 2(b), each slanted line represents an antenna, the four slanted lines in the solid line are in the first polarization direction, and the four slanted lines in the dashed line are in the second polarization direction.

[0064] The antenna port numbering is related to how the two antenna ports in each antenna group are numbered. Fig. 2(a) illustrates an example of antenna port numbering (e.g., the first antenna port numbering). As shown in Fig. 2(a), PG0 includes antenna ports 0 and 2, PG1 includes antenna ports 1 and 3, PG2 includes antenna ports 4 and 6, and PG3 includes antenna ports 5 and 7.

[0065] The antenna group layout is related to the arrangement of the four antenna groups. Fig. 2(a) illustrates Figure 1The antenna layout 3-a (i.e., 2×2) shown in. That is, four antenna groups are arranged in two columns, where each column has 2 rows. Fig. 2(b) shows the Figure 1 antenna layout 3-a (i.e., 1×4) shown in. That is, four antenna groups are arranged in four columns, where each column has 1 row.

[0066] The transmission from a UE with 4 coherent antenna groups to a TRP can be expressed as where H i , W i , X i are the channel, precoding matrix, and information from antenna group i (where i is any one from 0 to 3) to the TRP respectively, and N is the receiver noise vector.

[0067] According to the first embodiment, the precoding matrices in the NR version 15 2TX rank-1 codebook can be used to construct each of W0, W1, W2, and W3.

[0068] The 2TX rank-1 codebook is given as Table 6.3.1.5-1 specified in 3GPP technical specification TS38.211 V16.0.0 as follows:

[0069] Table 6.3.1.5-1: Precoding matrix W for single-layer transmission using two antenna ports.

[0070]

[0071] The 2TX rank-1 precoding matrices (with transmit precoding matrix indicator (TPMI) indices from 0 to 5) can be classified into two groups:

[0072] Denoted as , the first group of type #1 includes precoding matrices with indices from 0 to 1 (i.e., {TPMI indices 0-1}), where one port is selected from 2 ports for transmission (i.e., each precoding matrix in the precoding matrices with indices from 0 to 1 has only one non-zero value).

[0073] Denoted as , the second group of type #2 includes precoding matrices with indices from 2 to 5 (i.e., {TPMI indices 2-5}), where all two ports are used for transmission. The precoding matrices with indices from 2 to 5 in the 2TX rank-1 codebook given by Table 6.3.1.5-1 can be called 2TX rank-1 full-phase precoding matrices.

[0074] The first embodiment proposes that the 2TX rank-1 full-phase precoding matrix (i.e., )Can be used to construct each of W0, W1, W2, and W3. 8TX rank N (N ranges from 1 to 8) precoding matrix W N Adopt the form where a is a normalization factor. For example, for an 8TX precoding matrix, it is For the sake of discussion, all four 2TX rank-1 full-phase precoding matrices (i.e., ) are listed as follows: where the indices 0, 1, 2, 3 (instead of 2 to 5) can be used to indicate each of the four 2TX rank-1 full-phase precoding matrices.

[0075] The first embodiment is described by taking the antenna port numbers shown in Fig. 2(a) or 2(b) as the antenna port numbers. That is, PG0 includes antenna ports 0 and 2, where W0 is the precoding matrix for PG0 (i.e., for antenna ports 0 and 2); PG1 includes antenna ports 1 and 3, where W1 is the precoding matrix for PG1 (i.e., for antenna ports 1 and 3); PG2 includes antenna ports 4 and 6, where W2 is the precoding matrix for PG2 (i.e., for antenna ports 4 and 6); PG3 includes antenna ports 5 and 7, where W3 is the precoding matrix for PG3 (i.e., for antenna ports 5 and 7).

[0076] Depending on the rank from 1 to 8, a subset or all of the four antenna groups are used for transmission (details will be described later). Each antenna group PG i (i ranges from 0 to 3) The number of data layers to be sent can be 0, 1, or 2 (details will be described later). In the following description, "data layer" is abbreviated as "layer"). Therefore, each of W0 to W3 will be indicated for transmission with rank N (where N ranges from 1 to 8) (i.e., sending N layers). The rank of the 2TX precoding matrix (i.e., each of W0 to W3) for each antenna group used for transmission is 1 or 2.

[0077] The first sub-embodiment of the first embodiment relates to an 8TX rank-1 codebook for an 8TX UE with four coherent antenna groups, which includes 8TX rank-1 precoding matrices (W 1 ), each of which is constructed using one 2TX rank-1 full-phase precoding matrix.

[0078] For rank 1 with one layer, one layer is sent through only one of the four antenna groups (i.e., only one of W0 to W3 is non-zero), and the other three antenna groups are not used for transmission (i.e., the other three of W0 to W3 are zero). Any one of the four antenna groups (PG0, PG1, PG2, PG3) should be able to send one layer. Therefore, 2 bits are required to indicate one of the four antenna groups used for transmission. Additionally, from A rank-1 precoding matrix can be indicated by 2 bits as the precoding matrix for a indicated antenna group. Thus, for an 8TX UE with four coherent antenna groups, indicating an 8TX rank-1 precoding matrix (W 1 ) from an 8TX rank-1 codebook requires a total of 4 bits.

[0079] The second sub-embodiment of the first embodiment relates to an 8TX rank-2 codebook for an 8TX UE with four coherent antenna groups, which includes an 8TX rank-2 precoding matrix (W 2 ), each of which is constructed using two 2TX rank-1 full-phase precoding matrices.

[0080] For rank-2 with two layers, each of the two layers is transmitted by one antenna group out of four antenna groups (i.e., only two of W0 to W3 are non-zero), while the other two antenna groups are not used for transmission (i.e., the other two of W0 to W3 are zero). There are different combinations of two antenna groups. Additionally, if it is assumed that the first selected precoding matrix (i.e., the precoding matrix with the lower index among the two selected precoding matrices) is applied to the first indicated antenna group (i.e., the antenna group with the lower index among the two indicated antenna groups), and the second selected precoding matrix (i.e., the precoding matrix with the higher index among the two selected precoding matrices) is applied to the second indicated antenna group (i.e., the antenna group with the higher index among the two indicated antenna groups), then the two indicated antenna groups can select two different precoding matrices from with different combinations. Therefore, there are 36 = 6×6 different 8TX rank-2 precoding matrices (W 2 ) in the 8TX rank-2 codebook for an 8TX UE with four coherent antenna groups. It requires bits to indicate one precoding matrix out of 36 precoding matrices.

[0081] To reduce signaling overhead, some of the 36 precoding matrices can be removed. For example, if 4 precoding matrices out of 36 precoding matrices are removed, only 32 precoding matrices remain in the codebook for the 8TX rank-2 precoding matrix (W 2R ) for an 8TX UE with four coherent antenna groups. It will require bits to indicate one precoding matrix out of 32 precoding matrices.

[0082] The third sub-embodiment of the first embodiment relates to an 8TX rank-3 codebook for an 8TX UE with four coherent antenna groups, which includes an 8TX rank-3 precoding matrix (W 3), each of which is constructed using three 2TX rank-1 full-phase precoding matrices.

[0083] For rank 3 with three layers, each of the three layers is transmitted by one of four antenna groups (i.e., three of W0 to W3 are non-zero), while the other antenna group is not used for transmission (i.e., the other of W0 to W3 is zero). There are different combinations of the three antenna groups. Additionally, if it is assumed that the first selected precoding matrix (i.e., the precoding matrix with the lowest index among the three selected precoding matrices) is applied to the first indicated antenna group (i.e., the antenna group with the lowest index among the three indicated antenna groups); the second selected precoding matrix (i.e., the precoding matrix with the second lowest index among the three selected precoding matrices) is applied to the second indicated antenna group (i.e., the antenna group with the second lowest index among the three indicated antenna groups); and the third selected precoding matrix (i.e., the precoding matrix with the highest index among the three selected precoding matrices) is applied to the third indicated antenna group (i.e., the antenna group with the highest index among the three indicated antenna groups), then the three indicated antenna groups can select three different precoding matrices from with different combinations. Thus, there are 16 = 4×4 different 8TX rank-3 precoding matrices (W 3 ) in the 8TX rank-3 codebook for an 8TX UE with four coherent antenna groups. bits are required to indicate one of the 16 precoding matrices.

[0084] The fourth sub-embodiment of the first embodiment relates to an 8TX rank-4 codebook for an 8TX UE with four coherent antenna groups, which includes 8TX rank-4 precoding matrices (W 4 ), which are constructed using four 2TX rank-1 full-phase precoding matrices.

[0085] For a rank-4 precoding matrix with four layers, each of the four layers is transmitted by one antenna group. Additionally, all four precoding matrices in the first precoding matrix in the second precoding matrix the third precoding matrix and the fourth precoding matrix are applied to the first, second, third, and fourth antenna groups in sequential order, i.e., they are used as W0, W1, W2, and W3 respectively in sequential order. Thus, the 8TX rank-4 precoding matrix (W4 ) is fixed as where a is a normalization factor, such as There is no need for an explicit indication to indicate that there is only one 8TX rank 4 precoding matrix in the 8TX rank 4 codebook.

[0086] The above 8TX rank 4 precoding matrix (W 4 ) is obtained by assuming the antenna port numbers shown in Fig. 2(a) or 2(b).

[0087] Figure 3(a) and 3(b) respectively illustrate another antenna port number (e.g., the second antenna port number) for antenna layout 3-a (i.e., 2×2) and antenna layout 3-b (i.e., 1×4). As Figure 3(a) and 3(b) shown, PG0 includes antenna ports 0 and 4, PG1 includes antenna ports 1 and 5, PG2 includes antenna ports 2 and 6, and PG3 includes antenna ports 3 and 7.

[0088] A comparison between Fig. 3(a) or 3(b) and Fig. 2(a) or 2(b) can reveal that the antenna port numbers in Fig. 3(a) or 3(b) are equivalent to changing the sequence of antenna ports 0, 1, 2, 3, 4, 5, 6, 7 in Fig. 2(a) or 2(b) to the sequence of antenna ports 0, 1, 4, 5, 2, 3, 6, 7 in Table 1.

[0089]

[0090] Table 1

[0091] Each of the 8 antenna ports corresponds to a row of the 8TX rank N (N ranges from 1 to 8) precoding matrix, e.g., W 4 . When the sequence of antenna ports 0, 1, 2, 3, 4, 5, 6, 7 is changed to the sequence of antenna ports 0, 1, 4, 5, 2, 3, 6, 7, the corresponding rows of the 8TX rank N (N ranges from 1 to 8) precoding matrix, e.g., W 4 , should change in the same way. That is, if the antenna port numbers are as shown in Fig. 3(a) or 3(b), the 8TX rank 4 precoding matrix becomes where a is a normalization factor. That is, swap the second row (i.e., {0 1 0 0}) of W 4 and the fourth row (i.e., {0 0 1 0}) of W 4 (i.e., in W 4 ′, the second row is {0 0 1 0} and the fourth row is {0 1 0 0}), and swap the third row (i.e., {0 -1 0 0}) of W 4 and W 4Line 5 (i.e., {0 0 j 0}) is swapped (i.e., in W 4 ′, line 3 is {0 0 j 0} and line 5 is {0 -1 0 0}). From another perspective, W 4 can be constructed from W 4 ′. Specifically, the 0th row of W 4 ′ is the 0th row of W 4 ; the 1st row of W 4 ′ is the 1st row of W 4 ′; the 2nd row of W 4 ′ is the 4th row of W 4 ; the 3rd row of W 4 ′ is the 5th row of W 4 ; the 4th row of W 4 ′ is the 2nd row of W 4 ; the 5th row of W 4 ′ is the 3rd row of W 4 ; the 6th row of W 4 ′ is the 6th row of W 4 ; and the 7th row of W 4 ′ is the 7th row of W 4 .

[0092] The fifth sub - embodiment of the first embodiment relates to an 8TX rank - 5 codebook for an 8TX UE with four coherent antenna groups, which includes an 8TX rank - 5 precoding matrix (W 5 ), each of which is constructed using a 2TX rank - 1 full - phase precoding matrix.

[0093] For rank - 5 with five layers, all four coherent antenna groups need to transmit, where one of the four coherent antenna groups transmits 2 layers and each of the other three coherent antenna groups transmits 1 layer. For one coherent antenna group that transmits 2 layers, a rank - 2 precoding matrix can be constructed by adding a 2TX rank - 1 full - phase precoding matrix to the original 2TX rank - 1 full - phase precoding matrix applied to one coherent antenna group in an 8TX rank - 4 precoding matrix (W 4 ).

[0094] For rank - 5, there are two channel - coded words (e.g., CW0 and CW1), where CW0 is used in the first 2 layers and CW1 is used in the remaining 3 layers. Since it is best to transmit CW1 of 3 layers from 2 coherent antenna groups, it is proposed to add a 2TX rank - 1 full - phase precoding matrix w ad as the second column of a 2TX rank - 2 precoding matrix to PG2 or PG3.

[0095] For example, if the 2TX rank - 1 full - phase precoding matrix Added to PG2 as the second column, based on W 4 in the 2TX rank-1 full-phase precoding matrix W2 (i.e., ), the new rank-2 precoding matrix for PG2 becomes which is not normalized. Thus, by assuming the antenna port numbers shown in Fig. 2(a) or 2(b), the resulting 8TX rank-5 precoding matrix will be where a is the normalization factor.

[0096] The 8TX rank-5 precoding matrix based on other antenna port numbers can be obtained in the same way as above by rearranging the rows of W 5 from W 4 to obtain W 4 ′.

[0097] To transmit 2 layers from a coherent antenna group, the new 2TX rank-1 full-phase precoding matrix w ad should be different from the original 2TX rank-1 full-phase precoding matrix of the coherent antenna group in W 4 (this is called the restriction of "different rank-1 precoding matrices allowed for the same antenna group"). Since W 4 is fixed, cannot be added to PG2, and cannot be added to PG3. Thus, there are two antenna groups (PG2 and PG3) to be selected to add the new 2TX rank-1 full-phase precoding matrix W ad ; and for each of the selected antenna groups (PG2 or PG3), considering the restriction of "different rank-1 precoding matrices allowed for the same antenna group", three candidate new 2TX rank-1 full-phase precoding matrices can be further selected. Thus, there are 6 = 2×3 precoding matrices (W 5 ) in the 8TX rank-5 codebook for an 8TX UE with four coherent antenna groups. bits are needed to indicate one of the 16 precoding matrices.

[0098] The number of bits for indication can be reduced by removing some precoding matrices from W 5 to construct the reduced precoding matrix W 5R .

[0099] The sixth sub-embodiment of the first embodiment relates to an 8TX rank-6 codebook for an 8TX UE with four coherent antenna groups, which includes 8TX rank-6 precoding matrices (W 6 ), each of which is constructed using a 2TX rank-1 full-phase precoding matrix.

[0100] For rank 6 with six layers, all four antenna groups need to transmit, where two of the four antenna groups transmit 2 layers and each of the other two antenna groups transmits 1 layer. For each of the two coherent antenna groups that transmit 2 layers, a rank-2 precoding matrix can be constructed by adding a 2TX rank-1 full-phase interference coding matrix to the original 2TX rank-1 full-phase interference coding matrix applied to the coherent antenna groups in the 8TX rank-4 precoding matrix (W 4 )).

[0101] For rank 6, there are two channel coding words (e.g., CW0 and CW1), where CW0 is used for the first 3 layers and CW1 is used for the remaining 3 layers. Thus, the first 2TX rank-1 full-phase interference coding matrix w ad1 can be added to PG0 or PG1 as the second column; and the second 2TX rank-1 full-phase interference coding matrix w ad2 can be added to PG2 or PG3 as the second column.

[0102] For the first three layers, one of the two antenna groups (PG0 and PG1) can be selected to add the first 2TX rank-1 full-phase interference coding matrix w ad1 ; and for the last three layers, one of the two antenna groups (PG2 and PG3) can be selected to add the second 2TX rank-1 full-phase interference coding matrix w ad2 . The restriction of "different rank-1 precoding matrices allowed for the same antenna group" (referred to as the first restriction) still applies. This means that the first 2TX rank-1 full-phase interference coding matrix w ad1 should be different from the original 2TX rank-1 full-phase interference coding matrix of the coherent antenna group to which the first 2TX rank-1 full-phase interference coding matrix w 4 is added in W ad1 ; and the second 2TX rank-1 full-phase interference coding matrix w ad2 should be different from the original 2TX rank-1 full-phase interference coding matrix of the coherent antenna group to which the second 2TX rank-1 full-phase interference coding matrix w 4 is added in W ad2 . Additionally, a second restriction that all the added 2TX rank-1 full-phase interference coding matrices are different is also applied. This means that the first 2TX rank-1 full-phase interference coding matrix w ad1 is different from the second 2TX rank-1 full-phase interference coding matrix w ad2 .

[0103] Therefore, there are precoding matrices (W 6 ) in the 8TX rank-6 codebook for an 8TX UE with four coherent antenna groups. bits are required to indicate one of the 28 precoding matrices.

[0104] Among them, the first means to select one of the antenna groups PG0 and PG1; the second means to select one of the antenna groups PG2 and PG3; and (1*3 + 2*2) = 7 means that when one of the antenna groups PG0 and PG1 is selected and one of the antenna groups PG2 and PG3 is selected, considering the first constraint and the second constraint, there are 7 different combinations of w ad1 and w ad2 .

[0105] For example, if the four 2TX rank-1 full-phase precoding matrices are indexed as 0, 1, 2, and 3, and assuming that the antenna group PG0 and the antenna group PG2 are selected, then the candidate combinations of w ad1 and w ad2 are: (1,0), (1,3), (2,0), (2,1), (2,3), (3,0), and (3,1).

[0106] It is possible to reduce the number of bits used for indication by removing some precoding matrices from W 6 , and it is possible to construct the reduced number of precoding matrices W 6R .

[0107] The seventh sub-embodiment of the first embodiment relates to an 8TX rank-7 codebook for an 8TX UE with four coherent antenna groups, which includes 8TX rank-7 precoding matrices (W 7 ), each of which is constructed using 2TX rank-1 full-phase precoding matrices.

[0108] For rank 7 with seven layers, all four antenna groups need to be transmitted, where each of the three antenna groups among the four antenna groups transmits 2 layers and the other antenna group transmits 1 layer. For each of the three coherent antenna groups that transmit 2 layers, a rank-2 precoding matrix can be constructed by adding a 2TX rank-1 full-phase precoding matrix to the original 2TX rank-1 full-phase precoding matrix applied to the 8TX rank-4 precoding matrix (W 4 ).

[0109] For rank 7, there are two channel coding words (e.g., CW0 and CW1), where CW0 is used in the first 3 layers and CW1 is used in the remaining 4 layers. Therefore, the first 2TX rank-1 full-phase precoding matrix w ad1 can be added to PG0 or PG1 as the second column; the second 2TX rank-1 full-phase precoding matrix w ad2 can be added to PG2 as the second column; and the third 2TX rank-1 full-phase precoding matrix w ad3Added to PG3 as the second column.

[0110] For the first three layers, one of the two antenna groups (PG0 and PG1) can be selected to add the first 2TX rank-1 full-diversity precoding matrix w ad1 . The first constraint (i.e., the constraint on "different rank-1 precoding matrices allowed for the same antenna group") and the second constraint (i.e., the constraint that "all added 2TX rank-1 full-diversity precoding matrices are different") still apply. This means that the first 2TX rank-1 full-diversity precoding matrix w ad1 , the second 2TX rank-1 full-diversity precoding matrix w ad2 and the third 2TX rank-1 full-diversity precoding matrix w ad3 should each be different from each of the original 2TX rank-1 full-diversity precoding matrices of the coherent antenna group in which the first 2TX rank-1 full-diversity precoding matrix w 4 , the second 2TX rank-1 full-diversity precoding matrix w ad1 , the third 2TX rank-1 full-diversity precoding matrix w ad2 and the third 2TX rank-1 full-diversity precoding matrix w ad3 are added; and the first 2TX rank-1 full-diversity precoding matrix w ad1 , the second 2TX rank-1 full-diversity precoding matrix w ad2 and the third 2TX rank-1 full-diversity precoding matrix w ad3 are also different.

[0111] Therefore, there are precoding matrices (W 7 ) in the 8TX rank-7 codebook for an 8TX UE with four coherent antenna groups. It requires bits to indicate one of the 22 precoding matrices.

[0112] means selecting one of the antenna groups PG0 and PG1.

[0113] A(3,3)+3*3 = 11 means that when one of the antenna groups PG0 and PG1 is selected, considering the first and second constraints, there are 11 different combinations of w ad1 , w ad2 and w ad3 .

[0114] A(n,n) (where n is any one of 1 to 4) indicates the number of permutations of (0, 1, …, n - 1) in which no number is in its original position. For example, if n = 4, the original positions are (0, 1, 2, 3). According to this definition, (1, 2, 3, 0) is allowed, while (1, 2, 0, 3) is not allowed (because 3 is in its original position). It is easy to deduce that A(1, 1) = 0 and A(2, 2) = 1 (i.e., the original positions are (0, 1), and the only allowed permutation is (1, 0)). It is possible to deduce A(n, n) from Thus, it is possible to deduce that A(3, 3) = 2 and A(4, 4) = 9.

[0115] For example, assume that the antenna group PG0 is selected, and the candidate combinations of w ad1 、w ad2 and w ad3 are:

[0116] (2, 3, 0), (3, 0, 2),

[0117] (1, 0, 2), (2, 0, 1), (2, 1, 0),

[0118] (1, 3, 0), (3, 0, 1), (3, 1, 0),

[0119] (2, 3, 1), (3, 1, 2), (1, 3, 2)

[0120] Similarly, if the antenna group PG1 is selected, the candidate combinations of w ad1 、w ad2 and w ad3 are:

[0121] (2, 3, 1), (3, 1, 2),

[0122] (0, 1, 2), (2, 1, 0), (2, 0, 1),

[0123] (0, 3, 1), (3, 1, 0), (3, 0, 1)),

[0124] (2, 3, 0), (3, 0, 2), (0, 3, 2)

[0125] It is possible to construct the reduced precoding matrix W 7 by removing some precoding matrices from W 7R to reduce the number of bits used for indication.

[0126] The eighth sub - embodiment of the first embodiment relates to an 8TX rank - 8 codebook for an 8TX UE with four coherent antenna groups, which includes an 8TX rank - 8 precoding matrix (W 8), each of which is constructed using a 2TX rank-1 full-phase interference coding matrix.

[0127] For rank 8 with eight layers, all four antenna groups need to transmit, with each of the four antenna groups transmitting 2 layers. For each of the four coherent antenna groups transmitting 2 layers, a rank-2 precoding matrix can be constructed by adding a 2TX rank-1 full-phase interference coding matrix to the original 2TX rank-1 full-phase interference coding matrix applied to the coherent antenna groups in the 8TX rank-4 precoding matrix (W 4 ).

[0128] For rank 8, there are two channel-coded words (e.g., CW0 and CW1), where CW0 is used in the first 4 layers and CW1 is used in the remaining 4 layers. Therefore, the first 2TX rank-1 full-phase interference coding matrix w ad1 is added to PG0 as the second column; the second 2TX rank-1 full-phase interference coding matrix w ad2 is added to PG1 as the second column; the third 2TX rank-1 full-phase interference coding matrix w ad3 is added to PG2 as the second column; and the fourth 2TX rank-1 full-phase interference coding matrix w ad4 can be added to PG3 as the second column.

[0129] The first constraint (i.e., the constraint of "non-identical rank-1 precoding matrices allowed for the same antenna group") and the second constraint (i.e., the constraint of "all added 2TX rank-1 full-phase interference coding matrices are different") still apply.

[0130] Since all 4 antenna groups need to transmit two layers, there is no need to indicate the antenna group. There are A(4,4) = 9 precoding matrices (W 8 ) in the 8TX rank-8 codebook for an 8TX UE with four coherent antenna groups. It requires bits to indicate one of the 9 precoding matrices.

[0131] A(4,4) = 9 means that considering the first and second constraints, there are 9 different combinations of w ad1 , w ad2 , w ad3 and w ad4 .

[0132] w ad1 , w ad2 , w ad3 and w ad4 The candidate combinations are:

[0133] (1,0,3.2),(2, 3, 0, 1),(3,2,1, 0),

[0134] (2,0,3,1), (1,2,3,0), (3,0,1,2),

[0135] (1,3,0,2), (2,3,1,0), (3,2,0,1)

[0136] can construct the reduced precoding matrix W by removing some precoding matrices from W 8 to reduce the number of bits used for indication. 8R

[0137] Overall, according to the first embodiment, an 8TX rank N (N ranges from 1 to 8) codebook for an 8TX UE with four coherent antenna groups is constructed based on a 2TX rank-1 full-phase precoding matrix.

[0138] For rank N, where N ranges from 1 to 4, N antenna ports are used for transmission, and each antenna port transmits 1 layer using one 2TX rank-1 full-phase precoding matrix.

[0139] For rank N, where N ranges from 5 to 8, an additional N - 4 2TX rank-1 full-phase precoding matrices are indicated for N - 4 antenna groups to allow each of them to transmit 2 layers. Additionally, a first restriction is imposed such that when an antenna group is assigned two 2TX rank-1 full-phase precoding matrices, the two 2TX rank-1 full-phase precoding matrices are different. Furthermore, a second restriction is imposed such that all the additional N - 4 2TX rank-1 full-phase precoding matrices are different.

[0140] According to the first embodiment, each of CW0 and CW1 is transmitted from only 2 antenna groups.

[0141] Each of the above mechanisms restricts the size of the 8TX rank N (N ranges from 1 to 8) codebook to reduce computational and signaling overhead.

[0142] According to the second embodiment, the precoding matrices in the NR Release 15 4TX rank-1 to 4 codebook can be used to construct each of W0, W1, W2, and W3.

[0143] First, the antenna port numbering described with reference to FIGS. 2(a) and 2(b) is further explained. FIGS. 2(a) and 2(b) illustrate a first antenna port numbering, where the first antenna group PG0 includes antenna ports 0 and 2, the second antenna group PG1 includes antenna ports 1 and 3, the third antenna group PG2 includes antenna ports 4 and 6, and the fourth antenna group PG3 includes antenna ports 5 and 7. In the second embodiment, the antenna port numbering further includes the concept of antenna group pairs. As Figure 2(a) and 2(b) ​As shown, the first antenna group PG0 and the second antenna group PG1 form a first antenna group pair, and the third antenna group PG2 and the fourth antenna group PG3 form a second antenna group pair.

[0144] Under the condition that the transmitted information (modulation symbol) X of length r is split into where r = r1 + r2, 1 ≤ r1 ≤ 4 and 1 ≤ r2 ≤ 4, and

[0145]

[0146] [H0 H1]W 01 X 01 +[H2 H3]W 23 X 23 +N

[0147]

[0148] If X0 = X1 = X 01 , then the same signal is transmitted by two antenna groups (i.e., an antenna group pair) in a layer. From the first antenna group pair (e.g., Figure 2(a) and 2(b) PG0 and PG1 shown in 01 ), a modulation symbol vector X of length r1 (1 ≤ r1 ≤ 4) is transmitted. Based on a 4TX precoder (i.e., a precoding matrix) with a size of 4 times r1 (i.e., 4 rows and r1 columns) (e.g., W 01 ) with a rank = r1 can be decomposed into a pair of 2TX precoding matrices, each with a size of 2 times r1 (i.e., 2 rows and r1 columns) (e.g., W0 and W1). This means that the precoding matrix for each antenna group in the first antenna group pair can be derived from such a decomposition. For example, the first two rows of W 01 can be used as the precoding matrix W0 for the first antenna group PG0 in the first antenna group pair; and the last two rows of W 01 can be used as the precoding matrix W1 for the second antenna group PG1 in the first antenna group pair.

[0149] Incidentally, although X0 = X1 = X 01 , X is transmitted in both PG0 and PG1 01 , rather than each of PG0 and PG1 transmitting half of the layer of X 01 . This is because all layers of X 01 are transmitted in the ports of PG0 and PG1.

[0150] Similarly, if X2 = X3 = X 23, the same signal is transmitted through two antenna groups in the layer (i.e., an antenna group pair), and a modulated symbol vector X of length r2 (1 ≤ r2 ≤ 4) is transmitted from the second antenna group pair (e.g., PG2 and PG3 shown in Figure 2(a) and 2(b) ). Based on 23 . Based on a 4TX precoder (i.e., a precoding matrix) with a size of 4 by r2 (i.e., 4 rows and r2 columns) (e.g., W 23 ) with rank = r2 can be decomposed into a pair of 2TX precoding matrices each with a size of 2 by r2 (i.e., 2 rows and r1 columns) (e.g., W2 and W3). This means that the precoding matrix for each antenna group in the second antenna group pair can be derived from such a decomposition. For example, the first two rows of W 23 can be used as the precoding matrix W2 for the first antenna group PG2 in the second antenna group pair; and the last two rows of W 23 can be used as the precoding matrix W3 for the second antenna group PG3 in the second antenna group pair.

[0151] Incidentally, although X2 = X3 = X 23 , X is transmitted in both PG2 and PG3 23 , rather than each of PG2 and PG3 transmitting half of the layer of X 23 . This is because all layers of X 23 are transmitted in the ports of PG2 and PG3.

[0152] In the following description, for a transmission with rank r = r1 + r2, r1 represents the number of layers transmitted in the first antenna group pair (e.g., including PG0 and PG1), and r2 represents the number of layers transmitted in the second antenna group pair (e.g., including PG2 and PG3).

[0153] Based on the above analysis, the second embodiment proposes that a precoding matrix in the NR version 15 4TX rank N (N = 1 to 4) codebook can be decomposed into two 2TX rank N precoding matrices, each of which is used as the precoding matrix for one antenna group in an antenna group pair.

[0154] The precoding matrices in these NR version 15 4TX codebooks can be classified into different types based on their structure (i.e., the number of active transmit antenna ports and their relative phases).

[0155] In the present disclosure, the 4TX precoding matrices for each rank k can be classified into three groups. Each 4TX precoding matrix of each rank k in each of these three groups belongs to the same type. This means that each 4TX precoding matrix of each rank k can belong to one of three types, for example, Type #1, Type #2, and Type #3. Notion Denotes a set of 4TX precoding matrices with rank k and type t, that is, 4TX precoding matrices with all types and rank k.

[0156] The 4TX rank-1 codebook is given as follows by Table 6.3.1.5-2 (for DFT-s-OFDM) or Table 6.3.1.5-3 (for CP-OFDM) specified in 3GPP Technical Specification TS38.211 V16.0.0:

[0157] Table 6.3.1.5-2: Precoding matrix W for single-layer transmission using four antenna ports with transform precoding enabled.

[0158]

[0159] Table 6.3.1.5-3: Precoding matrix W for single-layer transmission using four antenna ports with transform precoding disabled

[0160]

[0161] The 4TX rank-1 precoding matrices (with TPMI indices from 0 to 27) can be classified into three groups:

[0162] The first group with Type #1: Includes precoding matrices with indices from 0 to 3 (i.e., {TPMI indices 0 - 3}): port selection precoding matrices, that is, one port is selected from 4 ports for transmission.

[0163] The second group with Type #2: Includes precoding matrices with indices from 4 to 11 (i.e., {TPMI indices 4 - 11}): port selection and in-phase precoding matrices, that is, a pair of antenna ports is selected for transmission, and an in-phase factor is applied to them.

[0164] The third group with Type #3: Includes precoding matrices with indices from 12 to 27 (i.e., {TPMI indices 12 - 27}): four-port in-phase precoding matrices, that is, all four ports are used for transmission, and an in-phase vector is applied to them.

[0165] It can be seen that is a partially phase-interfering coding matrix. This means that for each of the 4TX rank-1 precoding matrices with TPMI indices 4 - 11, two antenna ports are selected from the four antenna ports (i.e., there are two non-zero elements among the four elements in a column), and an in-phase factor is applied to them. When each of the 4TX rank-1 precoding matrices with TPMI indices 4 - 11 is decomposed into two 2TX rank-1 precoding matrices, if the two non-zero elements are in the same 2TX rank-1 precoding matrix, it can be used without performance degradation.

[0166] For antenna group 0 (PG0) and antenna group 1 (PG1) including four antenna ports [0, 1, 2, 3] as shown in Fig. 2(a) or 2(b), antenna ports [0, 2] belong to antenna group 0 and are coherent; antenna ports [1, 3] belong to antenna group 1 and are coherent. Each of the 4TX rank-1 precoding matrices with TPMI indices 4 - 7 uses only the antenna ports in antenna group 0 (PG0) (i.e., antenna ports [0, 2]); and each of the 4TX rank-1 precoding matrices with TPMI indices 8 - 11 uses only the antenna ports in antenna group 1 (PG1) (i.e., antenna ports [1, 3]). Therefore, these precoding matrices (the 4TX rank-1 precoding matrices with TPMI indices 4 - 11 in Table 6.3.1.5-2 (for DFT-s-OFDM) or Table 6.3.1.5-3 (for CP-OFDM)) can be used for PG0 and PG1 without performance degradation, even though the two antenna groups (PG0 and PG1) are not coherent with each other.

[0167] Similarly, for antenna group 2 (PG2) and antenna group 3 (PG3) including four antenna ports [4, 5, 6, 7] as shown in Fig. 2(a) or 2(b), antenna ports [4, 6] belong to antenna group 2 and are coherent; antenna ports [5, 7] belong to antenna group 3 and are coherent. Each of the 4TX rank-1 precoding matrices with TPMI indices 4 - 7 uses only the antenna ports in antenna group 2 (PG2) (i.e., antenna ports [4, 6]); and each of the 4TX rank-1 precoding matrices with TPMI indices 8 - 11 uses only the antenna ports in antenna group 3 (i.e., antenna ports [5, 7]). Therefore, these precoding matrices (the 4TX rank-1 precoding matrices with TPMI indices 4 - 11 in Table 6.3.1.5-2 (for DFT-s-OFDM) or Table 6.3.1.5-3 (for CP-OFDM)) can be used for PG2 and PG3 without performance degradation, even though the two antenna groups (PG2 and PG3) are not coherent with each other.

[0168] Overall, Each of the 4TX rank-1 precoding matrices in (Table 6.3.1.5-2 (for DFT-s-OFDM) or Table 6.3.1.5-3 (for CP-OFDM)) can be decomposed into two 2TX rank-1 precoding matrices, each of which can be used as the precoding matrix for one antenna group of each antenna group pair (e.g., the first antenna group pair including PG0 and PG1, or the second antenna group pair including PG2 and PG3).

[0169] The 4TX rank-2 codebook is given as follows in Table 6.3.1.5-5 specified in 3GPP Technical Specification TS38.211 V16.0.0:

[0170] Table 6.3.1.5-5: Precoding matrix W for dual-layer transmission using four antenna ports in the case of disabled transform precoding.

[0171]

[0172] The rank-2 precoding matrix (G 2 , with a TPMI index ranging from 0 to 21) can be classified into three groups:

[0173] The first group with type #1: Includes precoding matrices with indices from 0 to 5 (i.e., {TPMI indices 0 - 5}): port selection precoding matrices.

[0174] The second group with type #2: Includes precoding matrices with indices from 6 to 13 (i.e., {TPMI indices 6 - 13}): port selection and in-phase precoding matrices.

[0175] The third group with type #3: Includes precoding matrices with indices from 14 to 21 (i.e., {TPMI indices 14 - 21}): four-port in-phase precoding matrices.

[0176] is a partial interference precoding matrix. For each of the 4TX rank-2 precoding matrices with TPMI indices 6 - 13, each layer is transmitted by two antenna ports (i.e., there are two non-zero elements among the four elements in each column). The two antenna ports used to transmit one layer in each column are antenna port [0, 2] or antenna port [1, 3], which are in the same antenna group. Therefore, when decomposing these precoding matrices (the 4TX rank-2 precoding matrices with TPMI indices 6 - 13 in Table 6.3.1.5-5) into two 2TX rank-2 precoding matrices, there is no performance loss, and each 2TX rank-2 precoding matrix is used as the precoding matrix for one antenna group of each antenna group pair (e.g., the first antenna group pair including PG0 and PG1, or the second antenna group pair including PG2 and PG3). Overall, each of the 4TX rank-2 precoding matrices (in Table 6.3.1.5-5) can be decomposed into two 2TX rank-2 precoding matrices, and each 2TX rank-2 precoding matrix can be used as the precoding matrix for one antenna group of each antenna group pair.

[0177] The 4TX rank-3 codebook is given as follows in Table 6.3.1.5-6 specified in 3GPP Technical Specification TS38.211 V16.0.0:

[0178] Table 6.3.1.5-6: Precoding matrix W for three-layer transmission using four antenna ports in the case of disabled transform precoding.

[0179]

[0180] The rank-3 precoding matrix (G 3 , with TPMI indices from 0 to 6) can be classified into three groups:

[0181] The first group with type #1: includes the precoding matrix with index 0 (i.e., {TPMI index 0}): port selection precoding matrix.

[0182] The second group with type #2: includes the precoding matrices with indices 1 to 2 (i.e., {TPMI indices 1 - 2}): port selection and in-phase precoding matrix.

[0183] The third group with type #3: includes the precoding matrices with indices 3 to 6 (i.e., {TPMI indices 3 - 6}): four-port in-phase precoding matrix.

[0184] is a partial phase interference coding matrix. For each of the 4TX rank-3 precoding matrices with TPMI indices 1 - 2, two antenna ports in one antenna group (e.g., including antenna ports [0, 2]) are used to transmit the first layer with different in-phase factors, while each of the two antenna ports in the other antenna group (e.g., including antenna ports [1, 3]) transmits one layer (e.g., the second and third layers). Since two antenna ports from different antenna groups are not used to transmit layers, there is no performance degradation when these precoding matrices (the 4TX rank-3 precoding matrices with TPMI indices 1 - 2 in Table 6.3.1.5-6) are decomposed into two 2TX rank-3 precoding matrices, and each 2TX rank-3 precoding matrix is used as the precoding matrix for one antenna group of each antenna group pair (e.g., the first antenna group pair including PG0 and PG1, or the second antenna group pair including PG2 and PG3). Overall, each of the 4TX rank-3 precoding matrices (in Table 6.3.1.5-6) can be decomposed into two 2TX rank-3 precoding matrices, and each 2TX rank-3 precoding matrix can be used as the precoding matrix for one antenna group of each antenna group pair.

[0185] The 4TX rank-4 codebook is given as follows in Table 6.3.1.5-7 specified in 3GPP Technical Specification TS38.211 V16.0.0:

[0186] Table 6.3.1.5-7: Precoding matrix W for four-layer transmission using four antenna ports in the case of disabled transform precoding.

[0187]

[0188] The rank-4 precoding matrix (G 4 , with TPMI indices from 0 to 4) can be classified into three groups:

[0189] The first group with type #1: Includes the precoding matrix with index 0 (i.e., {TPMI index 0}): port selection precoding matrix.

[0190] The second group with type #2: Includes the precoding matrices with indices 1 to 2 (i.e., {TPMI indices 1 - 2}): port selection and in-phase precoding matrix.

[0191] The third group with type #3: Includes the precoding matrices with indices 3 to 6 (i.e., {TPMI indices 3 - 6}): four-port in-phase precoding matrix.

[0192] is a partial phase interference precoding matrix. Two antenna ports in one antenna group (e.g., including antenna ports [0, 2]) are used to transmit two layers with different in-phase factors (e.g., the first layer and the second layer), while two antenna ports in another group (e.g., including antenna ports [1, 3]) are used to transmit two other layers with different in-phase factors (e.g., the third layer and the fourth layer). Since two ports from different antenna groups are not used to transmit layers, there is no performance degradation when these precoding matrices (4TX rank-4 precoding matrices with TMPI indices 1 - 2 in Table 6.3.1.5 - 7) are decomposed into two 2TX rank-4 precoding matrices, and each 2TX rank-4 precoding matrix is used as the precoding matrix for one antenna group of each antenna group pair (e.g., the first antenna group pair including PG0 and PG1, or the second antenna group pair including PG2 and PG3). Overall, each of the 4TX rank-4 precoding matrices in (in Table 6.3.1.5 - 7) can be decomposed into two 2TX rank-4 precoding matrices, and each 2TX rank-4 precoding matrix can be used as the precoding matrix for one antenna group of each antenna group pair.

[0193] Overall, all 4TX rank-N (N ranges from 1 to 4) precoding matrices are listed in Table 2, and each of them can be decomposed into two 2TX rank-N precoding matrices, and each 2TX rank-N precoding matrix can be used as the precoding matrix for one antenna group of each antenna group pair:

[0194]

[0195] Table 2

[0196] The second embodiment proposes 8TX rank-N precoding matrices for an 8TX UE (UE with 8 antenna ports) having four coherent antenna groups using the 4TX rank-N (N ranges from 1 to 4) precoding matrices listed in Table 2, where N ranges from 1 to 8.

[0197] The second embodiment will describe the first antenna port numbers shown in Fig. 2(a) or Fig. 2(b) as antenna port numbers. That is, PG0 includes antenna ports 0 and 2, PG1 includes antenna ports 1 and 3, and PG0 and PG1 are the first antenna group pair associated with the precoding matrix where W0 is the precoding matrix for PG0 (i.e., for antenna ports 0 and 2), and W1 is the precoding matrix for PG1 (i.e., for antenna ports 1 and 3). PG2 includes antenna ports 4 and 6, PG3 includes antenna ports 5 and 7, and PG2 and PG3 are the antenna group pair associated with the precoding matrix Associated second antenna group pair, where W2 is the precoding matrix for PG2 (i.e., for antenna ports 4 and 6), and W3 is the precoding matrix for PG3 (i.e., for antenna ports 5 and 7).

[0198] The first sub - embodiment of the second embodiment relates to an 8TX rank - 1 codebook for an 8TX UE with four coherent antenna groups, which includes 8TX rank - 1 precoding matrices (W 1 ), each of which is constructed using one of two 4TX rank - 1 partially - interfering precoding matrices.

[0199] For rank - 1, one layer is transmitted through only one antenna group (i.e., through two antenna ports in one antenna group). To fully utilize the four antenna groups, any one of the four antenna groups should be able to transmit one layer. This means that W 01 is assigned to the first antenna group pair (which means 0 is assigned to the second antenna group pair) (i.e., the 8×1 precoding vector takes the form where is represented as "1 + 0"), or W 23 is assigned to the second antenna group pair (which means 0 is assigned to the first antenna group pair) (i.e., the 8×1 precoding vector takes the form where is represented as "0 + 1").

[0200] Use 1 bit to indicate whether W 01 is assigned to the first antenna group pair or W 23 is assigned to the second antenna group pair (i.e., whether the precoding matrix (or precoding vector) takes the form or the form It is possible to use 3 bits to indicate which one of the 8 4TX rank - 1 partially - interfering precoding matrices (i.e., 01 or W 23 ) is used in the indicated W ). Overall, for an 8TX UE with four coherent antenna groups, 4 bits are necessary to indicate the 8TX rank - 1 precoding matrix (W 1 ) using one of two 4TX rank - 1 partially - interfering precoding matrices.

[0201] Because any partially - interfering precoding matrix from uses only 2 antenna ports from one port antenna group, any one of the 4 antenna groups can be used to transmit one layer using any one of and .

[0202] Incidentally, the 4TX rank-1 precoding matrices with TPMI indices 4 - 11 are the same in Table 6.3.1.5-2 (for DFT-s-OFDM) and Table 6.3.1.5-3 (for CP-OFDM) (for the same indices).

[0203] The second sub-embodiment of the second embodiment relates to an 8TX rank-2 codebook for an 8TX UE with four coherent antenna groups, which includes 8TX rank-2 precoding matrices (W 2 ), each of which is constructed using two 4TX rank-1 partially interfering precoding matrices.

[0204] For rank-2 with two layers (e.g., the first layer and the second layer), each of the two layers is transmitted by an antenna group pair. That is, the first layer is transmitted by the first antenna group pair (e.g., including PG0 and PG1), and the second layer is transmitted by the second antenna group pair (e.g., including PG2 and PG3), which is referred to as "1 + 1". The 8×2 precoding matrix has the form where and Therefore, the 8TX rank-2 codebook includes a total of 8TX rank-2 precoding matrices. As a result, the first layer is transmitted by one of the antenna groups PG0 and PG1 in the first antenna group pair, and the second layer is transmitted by one of the antenna groups PG2 and PG3 in the second antenna group pair.

[0205] A reduced 8TX rank-2 codebook W 01 , W 23 can be obtained by allowing only certain combinations of (W 2R ) to reduce the size of the codebook. For example, if the same 4TX rank-1 partially interfering precoding matrix is not allowed to be used for and (i.e., it is required that W 01 ≠W 23 ), then the total number of precoding matrices for the reduced codebook W 2R will become |W 2 |-8 = 56.

[0206] A joint TPMI indication or a separate TPMI indication can be used to indicate the 8TX rank-2 precoding matrices from W 2 or W 2R .

[0207] If an 8TX rank-2 precoding matrix is indicated from W 2 or W 2R by a joint TPMI indication, each state represents a combination of (W 01 , W 23 ). In W 2In the case of, it is necessary to bits to indicate one of the 64 precoding matrices.

[0208] If the 8TX rank-2 precoding matrix is indicated from W through a separate TPMI 2 or W 2R and W is separately indicated 01 and W 23 . In the case of W 2 , it is necessary to bits to indicate one of the 8 precoding matrices for W 01 , and it is necessary to bits to indicate one of the 8 precoding matrices for W , and it is necessary to 23 , and bits to indicate one of the 8 precoding matrices for W

[0209] The third sub-embodiment of the second embodiment relates to an 8TX rank-3 codebook for an 8TX UE having four coherent antenna groups, which includes 8TX rank-3 precoding matrices (W 3 ), each of which is constructed using a 4TX rank-1 partial precoding matrix and a 4TX rank-2 partial precoding matrix.

[0210] For rank-3 with three layers (e.g., the first layer, the second layer, and the third layer), the first layer can be transmitted by the first antenna group pair (e.g., including PG0 and PG1), and each of the second layer and the third layer can be transmitted by the second antenna group pair (e.g., including PG2 and PG3), which is called "1 + 2". The 8×3 precoding matrix takes the form where and Therefore, the 8TX rank-3 codebook includes a total of 8TX rank-3 precoding matrices. As a result, the first layer is transmitted by one of the antenna groups PG0 and PG1 in the first antenna group pair, the second layer is transmitted by one of the antenna groups PG2 and PG3 in the second antenna group pair; and the third layer is transmitted by the other antenna group of the antenna groups PG2 and PG3 in the second antenna group pair.

[0211] For an 8TX UE having four coherent antenna groups, it is possible to use a joint TPMI indication or a separate TPMI indication to indicate the 8TX rank-3 precoding matrix from W 3 .

[0212] If the 8TX rank-3 precoding matrix is indicated from W through a joint TPMI indication 3 , each state represents (W 01 , W23 ) combination. It requires bits to indicate one of 64 precoding matrices.

[0213] If the 8TX rank-3 precoding matrix is indicated by a separate TPMI from W 3 indicates the 8TX rank-3 precoding matrix, then W 01 and W 23 are indicated separately. It requires bits to indicate one of 8 precoding matrices from the 01 for W and it requires bits to indicate one of 8 precoding matrices from the 23 for W That is, a total of 6 bits are required for a separate TPMI indication.

[0214] It is possible to obtain a reduced codebook W 01 , W 23 by allowing only certain combinations of (W 3R ), thus reducing the size of the 8TX rank-3 codebook. For example, it is required that the non-zero elements in the columns of W 01 and W 23 are different. For example, such as the corresponding to or the corresponding to of (W 01 , W 23 ) combinations are not allowed because the non-zero elements in the columns, that is, all appear in W 01 and W 23 (which means using 2-port rank-1 precoding matrices (precoding vectors) in groups PG0 (or PG1) and PG2 to transmit different layers). Although these antenna groups (PG0 and PG2, or PG1 and PG2) are non-coherent, they may still interfere with each other due to similar channel conditions. Therefore, it is best to avoid such combinations. In other words, only allow precoding matrices without two antenna ports using the same 2-port rank-1 precoding matrix (precoding vector) (that is, no two layers can share the same 2-port rank-1 precoding matrix (precoding vector)).

[0215] Specifically, to meet the above requirements, only the following (W 3R combinations are allowed for W 01 , W 23 ):

[0216]

[0217] Table 3

[0218] It can be seen from Table 3 that for each of the 8 4TX rank-2 partial interference precoding matrices for W 23 of it is possible to select a reduced number (i.e., 4) of 4TX rank-1 partial interference precoding matrices only from those for W 01 of . That is, for each of the 8 4TX rank-2 partial interference precoding matrices for W 23 selected there are only 4 valid 4TX rank-1 partial interference precoding matrices that can be selected from those for W 01 of selected. Therefore, for W 3R only 32 = 8×4 combinations of (W 01 , W 23 ) are allowed, which means that W 3R includes 32 8TX rank-3 precoding matrices.

[0219] It is possible to use a combined TPMI indication or a separate TPMI indication to indicate the 8TX rank-3 precoding matrices from W 3R .

[0220] If the 8TX rank-3 precoding matrices are indicated according to W 3R by a combined TPMI indication, then each state represents a combination of (W 01 , W 23 ). It requires bits to indicate one of the 64 precoding matrices.

[0221] If the 8TX rank-3 precoding matrices are indicated according to W 3R by a separate TPMI indication, then W 01 and W 23 are indicated separately. It requires bits to indicate one of the 8 precoding matrices according to those for W 23 of , and for the indicated W 23 it requires bits to indicate one of the 4 valid precoding matrices according to those for W 01 of . That is, a separate TPMI indication requires a total of 5 bits.

[0222] For rank 3 with three layers (e.g., a first layer, a second layer, and a third layer), if in addition to "1+2", "2+1" is also supported (i.e., the first layer and the second layer are transmitted by a first antenna pair (e.g., including PG0 and PG1), and the third layer is transmitted by a second antenna pair (e.g., including PG2 and PG3)), then additional bits are required to distinguish between "1+2" and "2+1".

[0223] The fourth sub - embodiment of the second embodiment relates to an 8TX rank - 4 codebook for an 8TX UE with four coherent antenna groups, which includes 8TX rank - 4 precoding matrices (W 4 ), each of which is constructed using two 4TX rank - 2 partial precoding matrices.

[0224] For rank 4 with four layers (e.g., a first layer, a second layer, a third layer, and a fourth layer), the first layer and the second layer can be transmitted by a first antenna pair (e.g., including PG0 and PG1), and the third layer and the fourth layer can be transmitted by a second antenna pair (e.g., including PG2 and PG3), which is referred to as "2+2". The 8×4 precoding matrix takes the form where and Therefore, the 8TX rank - 4 codebook includes a total of 8TX rank - 4 precoding matrices. As a result, each layer is transmitted by a separate antenna group. For example, the first layer is transmitted by one of the antenna groups PG0 and PG1 in the first antenna pair, the second layer is transmitted by the other antenna group of PG0 and PG1 in the first antenna pair, the third layer is transmitted by one of the antenna groups PG2 and PG3 in the second antenna pair; and the fourth layer is transmitted by the other antenna group of PG2 and PG3 in the second antenna pair.

[0225] For an 8TX UE with four coherent antenna groups, joint TPMI indication or individual TPMI indication can be used to indicate the 8TX rank - 4 precoding matrix according to W 4 indicate the 8TX rank - 4 precoding matrix.

[0226] If the 8TX rank - 4 precoding matrix is indicated according to W 4 by joint TPMI indication, then each state represents a combination of (W 01 ,W 23 ). It requires bits to indicate one of the 64 precoding matrices.

[0227] If the 8TX rank - 4 precoding matrix is indicated by individual TPMI indication according to W 4 , W 01 and W 23 are indicated separately. It requires bits to indicate one of eight precoding matrices according to the one for W 01 of and it requires bits to indicate one of eight precoding matrices according to the one for W 23 of a precoding matrix. That is, a total of 6 bits are required for a single TPMI indication.

[0228] It is possible to obtain a reduced codebook W 01 , W 23 ) by allowing only certain combinations of (W 4R ), reducing the size of the 8TX rank 4 codebook. For example, in the reduced codebook W 4R , only precoding matrices (i.e., any two layers cannot share the same 2-port rank 1 precoding matrix (precoding vector)) without two antenna ports of the same 2-port rank 1 precoding matrix (precoding vector) are allowed to be used. For example, (W , W 01 , W 23 ) like is not allowed because the 2-port rank 1 precoding matrix (precoding vector) appears in both W 01 and W 23 , that is, it is used in both PG0 (in the first antenna pair) and PG3 (in the second antenna pair).

[0229] Specifically, to meet the above requirements, for W 4R only the following (W 01 , W 23 ) combinations are allowed:

[0230]

[0231] Table 4

[0232] It can be seen from Table 4 that for each precoding matrix of the eight 4TX rank 2 partially interfering precoding matrices from the one for W 01 of , only a reduced number (i.e., 2) of 4TX rank 2 partially interfering precoding matrices can be selected from the one for W 23 of . That is, for each precoding matrix of the eight 4TX rank 2 partially interfering precoding matrices selected from the one for W 01 selected , there are only 2 valid 4TX rank 2 partially interfering precoding matrices that can be selected from the one for W 23 of . Therefore, for W 4R only (W01 , W 23 )'s 16 = 8 × 2 combinations, which means that W 4R includes 16 8TX rank 4 precoding matrices.

[0233] It is possible to use joint TPMI indication or individual TPMI indication to indicate the 8TX rank 4 precoding matrix from W 4R .

[0234] If the 8TX rank 4 precoding matrix is indicated from W 3R by joint TPMI indication, each state represents a combination of (W 01 , W 23 ). It requires bits to indicate one of the 16 precoding matrices.

[0235] If the 8TX rank 4 precoding matrix is indicated from W 4R by individual TPMI indication, then W 01 and W 23 are indicated separately. It requires bits to indicate one of the 8 precoding matrices from 01 for W , and for the indicated W 01 , it requires bits to indicate one of the 2 valid precoding matrices from 23 for W . That is, a total of 4 bits are required for individual TPMI indication.

[0236] The fifth sub - embodiment of the second embodiment relates to an 8TX rank 5 codebook for an 8TX UE with four coherent antenna groups, which includes 8TX rank 5 precoding matrices (W 5 ), each of which is constructed using one 4TX rank 2 partial precoding matrix and one 4TX rank 3 partial precoding matrix.

[0237] For rank 5 with five layers (e.g., the first layer, the second layer, the third layer, the fourth layer, and the fifth layer), the first layer and the second layer can be transmitted by the first antenna group pair (e.g., including PG0 and PG1), and the third layer, the fourth layer, and the fifth layer can be transmitted by the second antenna group pair (e.g., including PG2 and PG3), which is called "2 + 3". The 8X5 precoding matrix takes the form where and Therefore, the 8TX rank 5 codebook includes a total of 8TX rank 5 precoding matrices. As a result, each layer is transmitted by one antenna port or by two antenna ports in an antenna group.

[0238] For an 8TX UE with four coherent antenna groups, either joint TPMI indication or individual TPMI indication can be used to obtain from W 5 an indication of an 8TX rank-5 precoding matrix.

[0239] If the 8TX rank-5 precoding matrix is obtained from W 5 by joint TPMI indication, each state represents a combination of (W 01 , W 23 ). It requires bits to indicate one of the 16 precoding matrices.

[0240] If the 8TX rank-5 precoding matrix is indicated from W 5 by individual TPMI indication, W 01 and W 23 are indicated separately. It requires bits to indicate one of the 8 precoding matrices from 01 for W , and it requires bits to indicate one of the 2 precoding matrices from 23 for W . That is, a total of 4 bits are required for individual TPMI indication.

[0241] A reduced codebook W 01 , W 23 can be obtained by allowing only certain combinations of (W 5R ), reducing the size of the 8TX rank-5 codebook. For example, in the reduced codebook W 5R , only precoding matrices without two antenna ports using the same 2-port rank-1 precoding matrix (precoding vector) are allowed (i.e., no two layers can share the same 2-port rank-1 precoding matrix (precoding vector)). For example, combinations like of (W 01 , W 23 ) are not allowed because the 2-port rank-1 precoding matrix (precoding vector) appears in both W 01 and W 23 , i.e., it is used in either PG1 (in the first antenna group pair) or in the second layer and PG2 (in the second antenna group pair) or in both the third layer.

[0242] Specifically, to meet the above requirements, only the following combinations of (W 5R , W 01 , W 23 ) are allowed for W

[0243]

[0244] Table 5

[0245] It can be seen from Table 5 that for each of the 2 4TX rank-3 partial interference precoding matrices for W 23 's , only 4 reduced number (i.e., 4) 4TX rank-2 partial interference precoding matrices can be selected from W 01 's . That is to say, for each precoding matrix in the 2 4TX rank-3 partial interference precoding matrices for W 23 selected , there are only 4 valid 4TX rank-2 partial interference precoding matrices that can be selected from W 01 's selected. Therefore, for W 5R only 8 = 4×2 combinations of (W 01 , W 23 ) are allowed, which means that W 5R includes 8 8TX rank-5 precoding matrices.

[0246] The 8TX rank-5 precoding matrices from W 5R can be indicated using a joint TPMI indication or a separate TPMI indication.

[0247] If an 8TX rank-5 precoding matrix is indicated from W 5R by a joint TPMI indication, each state represents a combination of (W 01 , W 23 ). It requires bits to indicate one of the 8 precoding matrices.

[0248] If an 8TX rank-5 precoding matrix is indicated from W 58 by a separate TPMI indication, W 01 and W 23 are indicated separately. It requires bits to indicate one of the 2 precoding matrices from W 23 's , and for the indicated W 23 , it requires bits to indicate one of the 4 valid precoding matrices from W 01 's . That is to say, a total of 3 bits are required for a separate TPMI indication.

[0249] For rank 5 with five layers (e.g., a first layer, a second layer, a third layer, a fourth layer, and a fifth layer), if in addition to "2+3", "3+2" is also supported (i.e., the first layer, the second layer, and the third layer are transmitted by a first antenna pair (e.g., including PG0 and PG1), and the fourth layer and the fifth layer are transmitted by a second antenna pair (e.g., including PG2 and PG3)), then additional bits are required to distinguish between "2+3" and "3+2".

[0250] In addition, for "3+2" W 5R will be as follows:

[0251]

[0252] Table 6

[0253] That is, if the additional bit indicates "3+2", then a joint TPMI indication or a separate TPMI indication can be used to indicate the 8TX rank 5 precoding matrix from W for "3+2". 5R of the 8TX rank 5 precoding matrix.

[0254] If the 8TX rank 5 precoding matrix is indicated from W for "3+2" by a joint TPMI indication, then each combination of states (W 5R , W 01 ) is represented. In addition to the additional bit, 23 bits are also required to indicate one of the 8 precoding matrices for the joint TPMI indication.

[0255] If the 8TX rank 5 precoding matrix is indicated from W for "3+2" by a separate TPMI indication, then W 5R and W 01 are indicated separately. It requires 23 bits to indicate one of the 2 precoding matrices from for W 01 , and for the selected W 01 bits are required to indicate one of the 4 valid precoding matrices from for W 23 . That is, in addition to the additional bit, a total of 3 bits are required for the separate TPMI indication.

[0256] The sixth sub - embodiment of the second embodiment relates to an 8TX rank 6 codebook for an 8TX UE with four coherent antenna groups, which includes 8TX rank 6 precoding matrices (W 6 ), each of which is constructed using two 4TX rank 3 partial precoding matrices.​​

[0257] For rank 6 with six layers (e.g., the first layer, the second layer, the third layer, the fourth layer, the fifth layer, and the sixth layer), the first layer, the second layer, and the third layer can be transmitted by a first antenna pair (e.g., including PG0 and PG1), and the fourth layer, the fifth layer, and the sixth layer can be transmitted by a second antenna pair (e.g., including PG2 and PG3), which is referred to as "3 + 3". The 8×6 precoding matrix takes the form where and Therefore, the 8TX rank 6 codebook includes a total of precoding matrices. Thus, each layer is transmitted by one antenna port or by two antenna ports in an antenna group.

[0258] For an 8TX UE with four coherent antenna groups, joint TPMI indication or individual TPMI indication can be used to indicate an 8TX rank 6 precoding matrix from W 6 indication.

[0259] If the 8TX rank 6 precoding matrix is indicated from W 6 by joint TPMI indication, each state represents a combination of (W 01 , W 23 ). bits are required to indicate one of the 4 precoding matrices.

[0260] If the 8TX rank 6 precoding matrix is indicated from W 6 by individual TPMI indication, W 01 and W 23 are indicated separately. bits are required to indicate one of the 2 precoding matrices from 01 for W ; and bits are required to indicate one of the 2 precoding matrices from 23 for W . That is, a total of 2 bits are required for individual TPMI indication.

[0261] The seventh sub - embodiment of the second embodiment relates to an 8TX rank 7 codebook for an 8TX UE with four coherent antenna groups, which includes an 8TX rank 7 precoding matrix (W 7 ), each of which is constructed using one 4TX rank 3 partial - phase - interference precoding matrix and one 4TX rank 4 partial - phase - interference precoding matrix.

[0262] For rank 7 with seven layers (e.g., the first layer, the second layer, the third layer, the fourth layer, the fifth layer, the sixth layer, and the seventh layer), the first layer, the second layer, and the third layer can be transmitted by a first antenna pair (e.g., including PG0 and PG1), and the fourth layer, the fifth layer, the sixth layer, and the seventh layer can be transmitted by a second antenna pair (e.g., including PG2 and PG3), which is referred to as "3+4". The 8×7 precoding matrix takes the form where and Therefore, the 8TX rank 7 codebook includes a total of 8TX rank 7 precoding matrices. As a result, each layer is transmitted by one antenna port or by two antenna ports in an antenna group.

[0263] For an 8TX UE with four coherent antenna groups, it is possible to use joint TPMI indication or individual TPMI indication to indicate an 8TX rank 7 precoding matrix from W 7

[0264] If an 8TX rank 7 precoding matrix is indicated from W 7 by joint TPMI indication, each state represents a combination of (W 01 , W 23 ). It requires bits to indicate one of the 4 precoding matrices.

[0265] If an 8TX rank 7 precoding matrix is indicated from W 7 by individual TPMI indication, W 01 and W 23 are indicated separately. It requires bits to indicate one of the 2 precoding matrices from the 01 for W , and it requires bits to indicate one of the 2 precoding matrices from the 23 for W . That is, a total of 2 bits are required for individual TPMI indication.

[0266] It is possible to obtain a reduced codebook W 01 , W 23 by allowing only certain combinations of (W 7R ), reducing the size of the 8TX rank 7 codebook. For example, in the reduced codebook W 7R , only precoding matrices without two antenna ports using the same 2-port rank 1 precoding matrix (precoding vector) are allowed (i.e., no two layers can share the same 2-port rank 1 precoding matrix (precoding vector)). That is, for W 7R , only the following (W​01 , W 23 ) combination:

[0267]

[0268] Table 7

[0269] It can be seen from Table 7 that for each precoding matrix in the two 4TX rank-3 partial interference coding matrices for W 01 of , only a reduced number (i.e., 1) of 4TX rank-4 partial interference coding matrices for W 23 of can be selected. That is to say, for each precoding matrix in the two 4TX rank-3 partial interference coding matrices selected for W 01 selected , there is only 1 valid 4TX rank-4 partial interference coding matrix that can be selected from 23 of for W. Therefore, for W 7R only 2 = 1×2 combinations of (W 01 , W 23 ) are allowed, which means that W 7R includes 2 8TX rank-7 precoding matrices.

[0270] It takes bits to indicate one of the 2 precoding matrices from W 7R .

[0271] The eighth sub-embodiment of the second embodiment relates to an 8TX rank-8 codebook for an 8TX UE with four coherent antenna groups, which includes 8TX rank-8 precoding matrices (W 8 ), each of which is constructed using two 4TX rank-4 partial interference coding matrices.

[0272] For rank-8 with eight layers (e.g., the first layer, the second layer, the third layer, the fourth layer, the fifth layer, the sixth layer, the seventh layer, and the eighth layer), the first layer, the second layer, the third layer, and the fourth layer can be transmitted by the first antenna group pair (e.g., including PG0 and PG1), and the fifth layer, the sixth layer, the seventh layer, and the eighth layer can be transmitted by the second antenna group pair (e.g., including PG2 and PG3), which is called "4 + 4". The 8×8 precoding matrix takes the form where and Therefore, the 8TX rank-8 codebook includes a total of precoding matrices. As a result, each layer is transmitted by two antenna ports in the antenna group.

[0273] For an 8TX UE with four coherent antenna groups, either joint TPMI indication or individual TPMI indication can be used to obtain an 8TX rank-8 precoding matrix from W 8 to indicate an 8TX rank-8 precoding matrix.

[0274] If an 8TX rank-8 precoding matrix is indicated from W 8 by joint TPMI indication, each state represents a combination of (W 01 , W 23 ). It requires bits to indicate one of the four precoding matrices.

[0275] If an 8TX rank-8 precoding matrix is indicated from W 8 by individual TPMI indication, W 01 and W 23 are indicated separately. It requires bits to indicate one of the two precoding matrices from the 01 for W , and it requires bits to indicate one of the two precoding matrices from the 23 for W . That is, a total of 2 bits are required for individual TPMI indication.

[0276] A reduced codebook W 01 , W 23 ) can be obtained by allowing only certain combinations of (W 8R , reducing the size of the 8TX rank-6 codebook. For example, in the reduced codebook W 8R , only precoding matrices (i.e., any two layers cannot share the same 2-port rank-1 precoding matrix (precoding vector)) without two antenna ports using the same 2-port rank-1 precoding matrix (precoding vector) are allowed. That is, for W 8R , only the following (W 01 , W 23 ) combinations are allowed:

[0277]

[0278] Table 8

[0279] As can be seen from Table 8, for each precoding matrix from the two 4TX rank-4 partially interfering precoding matrices for W 01 from the , a reduced number (i.e., 1) of 4TX rank-4 partially interfering precoding matrices can be selected from the 23 for W . That is, for each selected for W 01 ​ For each of the two 4TX rank-4 partial interference precoding matrices, there is only one precoding matrix that can be selected from the ones for W 23 of to be a valid 4TX rank-4 partial interference precoding matrix. Therefore, for W 8R only allows 2 = 1×2 combinations of (W 01 , W 23 ), which means that W 7R includes two 8TX rank-8 precoding matrices.

[0280] It is necessary to bits to indicate one of the two precoding matrices from W 8R .

[0281] In addition, it is possible to only allow or only allow Under this condition, since there is only one possible combination of (W01, W23), it is indicated by default.

[0282] The first to eighth sub-embodiments of the above-described second embodiment are described by considering the antenna port numbers shown in Figure 2(a) and 2(b) . The first to eighth sub-embodiments of the above second embodiment are also applicable to other antenna port numbers, such as Figure 3(a) and 3(b) , Figure 4(a) and 4(b) or Figure 5(a) and 5(b) and the like shown in.

[0283] Figure 3(a) and 3(b) illustrate the second antenna port number. PG0 includes antenna ports 0 and 4, PG1 includes antenna ports 1 and 5, PG2 includes antenna ports 2 and 6, and PG3 includes antenna ports 3 and 7. Additionally, PG0 and PG1 are grouped together as the first antenna pair; and PG2 and PG3 are grouped together as the second antenna pair. It can be seen that the difference between the second antenna port number and the first antenna port number (i.e., the antenna port numbers shown in Figure 2(a) and 2(b) ) is that each antenna group includes different antenna ports, while the antenna groups in each antenna pair are the same.

[0284] Figure 4(a) and 4(b)Illustrate the third antenna port numbering. PG0 includes antenna ports 0 and 2, PG1 includes antenna ports 1 and 3, PG2 includes antenna ports 4 and 6, and PG3 includes antenna ports 5 and 7. Additionally, PG0 and PG2 are grouped together as the first antenna pair; and PG1 and PG3 are grouped together as the second antenna pair. It can be seen that the difference between the third antenna port numbering and the first antenna port numbering is that the antenna groups in each antenna pair are different, while the antenna ports included in each antenna group are the same.

[0285] Figure 5(a) and 5(b) Illustrate the fourth antenna port numbering. PG0 includes antenna ports 0 and 4, PG1 includes antenna ports 1 and 5, PG2 includes antenna ports 2 and 6, and PG3 includes antenna ports 3 and 7. Additionally, PG0 and PG2 are grouped together as the first antenna pair; and PG1 and PG3 are grouped together as the second antenna pair. It can be seen that the difference between the fourth antenna port numbering and the first antenna port numbering is that the antenna groups in each antenna pair are different and the antenna ports included in each antenna group are different.

[0286] The antenna port numbering in Fig. 3(a) or 3(b) (as well as in Fig. 4(a) or 4(b) and Fig. 5(a) or 5(b)) is equivalent to changing the sequence of antenna ports 0, 1, 2, 3, 4, 5, 6, 7 in Fig. 2(a) or 2(b) to the sequence of antenna ports 0, 1, 4, 5, 2, 3, 6, 7 (for Fig. 3(a) or 3(b)), the sequence of antenna ports 0, 4, 2, 6, 1, 5, 3, 7 (for Fig. 4(a) or 4(b)), and the sequence of antenna ports 0, 2, 4, 6, 1, 3, 5, 7 (for Fig. 5(a) or 5(b)), as shown in Table 9.

[0287] Figure 2(a) or 2(b) 1 2 3 4 5 6 7 Figure 3(a) or 3(b) 1 <![CDATA 4 > <![CDATA 5 > <![CDATA 2 > <![CDATA 3 > 6 7 Figure 4(a) or 4(b) <![CDATA 4 > 2 <![CDATA 6 > <![CDATA 1 > 5 <![CDATA 3 > 7 Figure 5(a) or 5(b) <![CDATA 2 > <![CDATA 4 > <![CDATA 6 > <![CDATA 1 > <![CDATA 3 > <![CDATA 5 > 7

[0288] Table 9

[0289] Each of the 8 antenna ports corresponds to a row of the precoding matrix for 8TX rank N (where N ranges from 1 to 8). When the sequence of antenna ports 0, 1, 2, 3, 4, 5, 6, 7 is changed to the sequence of antenna ports 0, 1, 4, 5, 2, 3, 6, 7, the corresponding rows of the precoding matrix for 8TX rank N (where N ranges from 1 to 8) should also be changed in the same way.

[0290] For example, if the rank 6 precoding matrix for the antenna port numbering shown in Fig. 2(a) and Fig. 2(b) is then when the second and fourth rows are swapped and the third and fifth rows are swapped, the rank 6 precoding matrix for the second antenna port numbering shown in Fig. 3(a) and Fig. 3(b) can be constructed as

[0291]

[0292] From another perspective, according to the sequence correspondence relationship between the antenna port numbers, W can be constructed from 6 Construct W 6 ′. Specifically, the 0th row of W 6 ′ is the 0th row of W 6 ; the 1st row of W 6 ′ is the 1st row of W 6 ; the 2nd row of W 6 ′ is the 4th row of W 6 ; the 3rd row of W 6 ′ is the 5th row of W 6 ; the 4th row of W 6 ′ is the 2nd row of W 6 ′; the 5th row of W 6 ′ is the 3rd row of W 6 ; the 6th row of W 6 ′ is the 6th row of W 6 ; and the 7th row of W 6 ′ is the 7th row of W 6 .

[0293] Similarly, when the 1st row and the 4th row of W 6 are swapped and the 3rd row and the 6th row of W 6 are swapped, the rank-6 precoding matrix for the third antenna port number shown in Figure 4(a) and 4(b) can be constructed as

[0294] From another perspective, according to the sequence correspondence relationship between the antenna port numbers, W 6 can be constructed into W 6 ″. Specifically, the 0th row of W 6 ″ is the 0th row of W 6 ; the 1st row of W 6 ″ is the 4th row of W 6 ; the 2nd row of W 6 ″ is the 2nd row of W 6 ; the 3rd row of W 6 ″ is the 6th row of W 6 ; the 4th row of W 6 ″ is the 1st row of W 6 ; the 5th row of W 6 ″ is the 5th row of W 6 ; the 6th row of W 6 ″ is the 3rd row of W 6 ; and the 7th row of W 6 ″ is the 7th row of W 6 .

[0295] Similarly, it is possible to obtain from W 6 Construct as follows for Figure 5(a) and 5(b) The rank 6 precoding matrix for the fourth antenna port number shown in: W 6 The 0th row of W″′ is the 0th row of W 6 ; The 0th row of W 6 The 1st row of W″′ is the 4th row of W 6 ; The 4th row of W 6 The 2nd row of W″′ is the 1st row of W 6 ; The 1st row of W 6 The 3rd row of W″′ is the 5th row of W 6 ; The 5th row of W 6 The 4th row of W″′ is the 2nd row of W 6 ; The 2nd row of W 6 The 5th row of W″′ is the 6th row of W 6 ; The 6th row of W 6 The 6th row of W″′ is the 3rd row of W 6 ; And the 3rd row of W 6 The 7th row of W″′ is the 7th row of W 6 ; Therefore,

[0296] Overall, by rearranging the rows of the 8TX rank N (N ranges from 1 to 8) precoding matrix obtained by considering the first antenna port number according to the sequence correspondence between any antenna port number and the first antenna port number, it is possible to construct an 8TX rank N (N ranges from 1 to 8) precoding matrix by considering any antenna port number from the 8TX rank N (N ranges from 1 to 8) precoding matrices determined by the first to eighth sub - embodiments according to the second embodiment.

[0297] According to the third embodiment, the joint TPMI indication or the separate TPMI indication described in the first embodiment or the second embodiment can be implemented in the TPMI included in the TPMI field. The TPMI field can be used in DCI format 0_1 or 0_2 to schedule a dynamically scheduled PUSCH or a type 2 configured grant PUSCH, or can be used in an RRC message (configuredGrantConfig) to configure a type 1 configured grant PUSCH.

[0298] Figure 6 FIG. is a schematic flowchart illustrating an embodiment of method 600 according to the present application. In some embodiments, method 600 is executed by a device such as a remote unit (e.g., UE). In certain embodiments, method 600 can be executed by a processor that executes program code, such as a microcontroller, a microprocessor, a CPU, a GPU, an auxiliary processing unit, an FPGA, etc.

[0299] Method 600 is a method performed at a UE and includes: 602 receiving a control message that schedules a PUSCH transmission with a transmission rank N to be sent by eight antenna ports among four coherent antenna groups, where the control message includes a TPMI indicating an 8TX precoding matrix used by the four coherent antenna groups, and where N is any one of 1 to 8; and 604 sending the scheduled PUSCH transmission according to the control message.

[0300] In some embodiments, the four coherent antenna groups are divided into two antenna group pairs, each antenna group pair consisting of two coherent antenna groups, and the TMPI indicates one or two 4TX partial precoding matrices, each 4TX partial precoding matrix being used by one of the two antenna group pairs.

[0301] In some embodiments, each 4TX partial precoding matrix is split into two 2TX precoding matrices, each 2TX precoding matrix being used as the precoding matrix for one of the two coherent antenna groups in the antenna group pair using the 4TX partial precoding matrix. If the transmission rank is 1, one 4TX partial precoding matrix is a 4TX rank-1 precoding matrix and is used by one antenna group pair indicated by the TPMI. If the transmission rank is 2, both 4TX partial precoding matrices are 4TX rank-1 precoding matrices. If the transmission rank is 3, one of the two 4TX partial precoding matrices is a 4TX rank-1 precoding matrix and the other of the two 4TX partial precoding matrices is a 4TX rank-2 precoding matrix. If the transmission rank is 4, both 4TX partial precoding matrices are 4TX rank-2 precoding matrices. If the transmission rank is 5, one of the two 4TX partial precoding matrices is a 4TX rank-2 precoding matrix and the other of the two 4TX partial precoding matrices is a 4TX rank-3 precoding matrix. If the transmission rank is 6, both 4TX partial precoding matrices are 4TX rank-3 precoding matrices. If the transmission rank is 7, one of the two 4TX partial precoding matrices is a 4TX rank-3 precoding matrix and the other of the two 4TX partial precoding matrices is a 4TX rank-4 precoding matrix. If the transmission rank is 8, both 4TX partial precoding matrices are 4TX rank-4 precoding matrices.

[0302] In some embodiments, each 4TX partial precoding matrix is selected from all 4TX partial precoding matrices of an appropriate rank.

[0303] In some embodiments, at least one of the two partial precoding matrices is selected only from a part of the 4TX partial precoding matrices of an appropriate rank. Specifically, the 2TX precoding matrix of each coherent antenna group is different from the 2TX precoding matrix of any other coherent antenna group.

[0304] In some embodiments, the TPMI includes a single indication of a 4TX partial interference precoding matrix or a combination of two 4TX partial interference precoding matrices.

[0305] Alternatively, the TPMI includes a first part indicating one of two 4TX partial interference precoding matrices and a second part indicating the other of the two 4TX partial interference precoding matrices. Specifically, the second part indicates the other of the two 4TX partial interference precoding matrices from a subset of precoding matrices of an appropriate rank based on the indication of one of the two 4TX partial interference precoding matrices by the first part; or the first part indicates one of the two 4TX partial interference precoding matrices from a subset of precoding matrices of an appropriate rank based on the indication of the other of the two 4TX partial interference precoding matrices by the second part.

[0306] In some embodiments, depending on the antenna port number, each of the two split 2TX precoding matrices is applied to a coherent antenna group including two antenna ports.

[0307] In some embodiments, the TPMI indicates a combination of coherent antenna groups and a 2TX rank-1 full-phase precoding matrix. If the transmission rank is 1, the TMPI indicates one of the four coherent antenna groups and a 2TX rank-1 full-phase precoding matrix. If the transmission rank is 2, the TMPI indicates a combination of two of the four coherent antenna groups and a combination of two 2TX rank-1 full-phase precoding matrices. If the transmission rank is 3, the TMPI indicates a combination of three of the four coherent antenna groups and a combination of three 2TX rank-1 full-phase precoding matrices. If the transmission rank is 4, the 8TX rank-4 precoding matrix consists of four 2TX rank-1 full-phase precoding matrices, where the four 2TX rank-1 full-phase precoding matrices are applied to the four coherent antenna groups in a sequential manner. If the transmission rank is 5, the TPMI indicates which one of the third and fourth coherent antenna groups with a 2TX rank-1 full-phase precoding matrix added and which one of the four 2TX rank-1 full-phase precoding matrices is the added 2TX rank-1 full-phase precoding matrix. If the transmission rank is 6, the TPMI indicates which one of the first and second coherent antenna groups with the first 2TX rank-1 full-phase precoding matrix added and which one of the third and fourth coherent antenna groups with the second 2TX rank-1 full-phase precoding matrix added, and which one of the four 2TX rank-1 full-phase precoding matrices is the added first 2TX rank-1 full-phase precoding matrix and which one of the four 2TX rank-1 full-phase precoding matrices is the added second 2TX rank-1 full-phase precoding matrix. If the transmission rank is 7, the TPMI indicates which one of the first and second coherent antenna groups with the first 2TX rank-1 full-phase precoding matrix added, which one of the four 2TX rank-1 full-phase precoding matrices is the added first 2TX rank-1 full-phase precoding matrix, which one of the four 2TX rank-1 full-phase precoding matrices is the second 2TX rank-1 full-phase precoding matrix added to the third coherent antenna group, and which one of the four 2TX rank-1 full-phase precoding matrices is the third 2TX rank-1 full-phase precoding matrix added to the fourth coherent antenna group. If the transmission rank is 8, the TPMI indicates which one of the four 2TX rank-1 full-phase precoding matrices is the first 2TX rank-1 full-phase precoding matrix added to the first coherent antenna group, which one of the four 2TX rank-1 full-phase precoding matrices is the second 2TX rank-1 full-phase precoding matrix added to the second coherent antenna group, which one of the four 2TX rank-1 full-phase precoding matrices is the third 2TX rank-1 full-phase precoding matrix added to the third coherent antenna group, and which one of the four 2TX rank-1 full-phase precoding matrices is the fourth 2TX rank-1 full-phase precoding matrix added to the fourth coherent antenna group.Specifically, each added 2TX rank-1 full-phase interference precoding matrix is different from the 2TX rank-1 full-phase interference precoding matrix initially applied to the coherent antenna group in which the added 2TX rank-1 full-phase interference precoding matrix is added to the 8TX rank-4 precoding matrix; and if there are two, three, or four added 2TX rank-1 full-phase interference precoding matrices, each precoding matrix among the two or three or four added 2TX rank-1 full-phase interference precoding matrices is different.

[0308] In some embodiments, if the transmission rank is r which is greater than 4, the TPMI indicates r - 4 2TX rank-1 full-phase interference precoding matrices, and each 2TX rank-1 full-phase interference precoding matrix is added to one of the r - 4 antenna groups based on the 8TX rank-4 precoding matrix. If r is 5, one 2TX rank-1 full-phase interference precoding matrix is added to the third antenna group or the fourth antenna group. If r is 7, one 2TX rank-1 full-phase interference precoding matrix is added to the first antenna group or the second antenna group, and two 2TX rank-1 full-phase interference precoding matrices are added to the third antenna group and the fourth antenna group. Each antenna group in which a 2TX rank-1 full-phase interference precoding matrix is added transmits two data layers.

[0309] Figure 7 FIG. is a schematic flowchart illustrating an embodiment of method 700 according to the present application. In some embodiments, method 700 is performed by a device such as a base station unit. In certain embodiments, method 700 may be performed by a processor executing program code, for example, a microcontroller, a microprocessor, a CPU, a GPU, an auxiliary processing unit, an FPGA, etc.

[0310] Method 700 may include: 702 transmitting a control message that schedules a PUSCH transmission with a transmission rank N to be transmitted by eight antenna ports in four coherent antenna groups, where the control message includes a TPMI indicating an 8TX precoding matrix used by the four coherent antenna groups, and where N is any one of 1 to 8; and 704 receiving the scheduled PUSCH transmission transmitted according to the control message.

[0311] In some embodiments, the four coherent antenna groups are divided into two antenna group pairs, each antenna group pair consisting of two coherent antenna groups, and the TMPI indicates one or two 4TX partial interference precoding matrices, and each 4TX partial interference precoding matrix is used by one of the two antenna group pairs.

[0312] In some embodiments, each 4TX partial interference precoding matrix is split into two 2TX precoding matrices, and each 2TX precoding matrix is used as the precoding matrix for one of the two coherent antenna groups in an antenna group pair using the 4TX partial interference precoding matrix. If the transmission rank is 1, one 4TX partial interference precoding matrix is a 4TX rank-1 precoding matrix and is used by an antenna group pair indicated by the TPMI. If the transmission rank is 2, both 4TX partial interference precoding matrices are 4TX rank-1 precoding matrices. If the transmission rank is 3, one of the two 4TX partial interference precoding matrices is a 4TX rank-1 precoding matrix and the other of the two 4TX partial interference precoding matrices is a 4TX rank-2 precoding matrix. If the transmission rank is 4, both 4TX partial interference precoding matrices are 4TX rank-2 precoding matrices. If the transmission rank is 5, one of the two 4TX partial interference precoding matrices is a 4TX rank-2 precoding matrix and the other of the two 4TX partial interference precoding matrices is a 4TX rank-3 precoding matrix. If the transmission rank is 6, both 4TX partial interference precoding matrices are 4TX rank-3 precoding matrices. If the transmission rank is 7, one of the two 4TX partial interference precoding matrices is a 4TX rank-3 precoding matrix and the other of the two 4TX partial interference precoding matrices is a 4TX rank-4 precoding matrix. If the transmission rank is 8, both 4TX partial interference precoding matrices are 4TX rank-4 precoding matrices.

[0313] In some embodiments, each 4TX partial interference precoding matrix is selected from all 4TX partial interference precoding matrices of the appropriate rank.

[0314] In some embodiments, at least one of the two partial interference precoding matrices is selected only from a part of the 4TX partial interference precoding matrices of the appropriate rank. Specifically, the 2TX precoding matrix of each coherent antenna group is different from the 2TX precoding matrix of any other coherent antenna group.

[0315] In some embodiments, the TPMI includes a single indication of a combination of one 4TX partial interference precoding matrix or two 4TX partial interference precoding matrices.

[0316] Alternatively, the TPMI includes a first part indicating one of two 4TX partial interference coding matrices and a second part indicating the other of the two 4TX partial interference coding matrices. Specifically, the second part indicates the other of the two 4TX partial interference coding matrices from a subset of precoding matrices of an appropriate rank based on the indication of one of the two 4TX partial interference coding matrices by the first part; or the first part indicates one of the two 4TX partial interference coding matrices from a subset of precoding matrices of an appropriate rank based on the indication of the other of the two 4TX partial interference coding matrices by the second part.

[0317] In some embodiments, depending on the antenna port number, each of the two split 2TX precoding matrices is applied to a coherent antenna group including two antenna ports.

[0318] In some embodiments, the TPMI indicates a combination of coherent antenna groups and a 2TX rank-1 full-phase precoding matrix. If the transmission rank is 1, the TMPI indicates one of the four coherent antenna groups and a 2TX rank-1 full-phase precoding matrix. If the transmission rank is 2, the TMPI indicates a combination of two of the four coherent antenna groups and a combination of two 2TX rank-1 full-phase precoding matrices. If the transmission rank is 3, the TMPI indicates a combination of three of the four coherent antenna groups and a combination of three 2TX rank-1 full-phase precoding matrices. If the transmission rank is 4, the 8TX rank-4 precoding matrix consists of four 2TX rank-1 full-phase precoding matrices, where the four 2TX rank-1 full-phase precoding matrices are applied to the four coherent antenna groups in a sequential manner. If the transmission rank is 5, the TPMI indicates which one of the third and fourth coherent antenna groups with a 2TX rank-1 full-phase precoding matrix added and which one of the four 2TX rank-1 full-phase precoding matrices is the added 2TX rank-1 full-phase precoding matrix. If the transmission rank is 6, the TPMI indicates which one of the first and second coherent antenna groups with the first 2TX rank-1 full-phase precoding matrix added and which one of the third and fourth coherent antenna groups with the second 2TX rank-1 full-phase precoding matrix added, and which one of the four 2TX rank-1 full-phase precoding matrices is the added first 2TX rank-1 full-phase precoding matrix and which one of the four 2TX rank-1 full-phase precoding matrices is the added second 2TX rank-1 full-phase precoding matrix. If the transmission rank is 7, the TPMI indicates which one of the first and second coherent antenna groups with the first 2TX rank-1 full-phase precoding matrix added, and which one of the four 2TX rank-1 full-phase precoding matrices is the added first 2TX rank-1 full-phase precoding matrix, which one of the four 2TX rank-1 full-phase precoding matrices is the second 2TX rank-1 full-phase precoding matrix added to the third coherent antenna group, and which one of the four 2TX rank-1 full-phase precoding matrices is the third 2TX rank-1 full-phase precoding matrix added to the fourth coherent antenna group. If the transmission rank is 8, the TPMI indicates which one of the four 2TX rank-1 full-phase precoding matrices is the first 2TX rank-1 full-phase precoding matrix added to the first coherent antenna group, which one of the four 2TX rank-1 full-phase precoding matrices is the second 2TX rank-1 full-phase precoding matrix added to the second coherent antenna group, which one of the four 2TX rank-1 full-phase precoding matrices is the third 2TX rank-1 full-phase precoding matrix added to the third coherent antenna group, and which one of the four 2TX rank-1 full-phase precoding matrices is the fourth 2TX rank-1 full-phase precoding matrix added to the fourth coherent antenna group.Specifically, each added 2TX rank-1 full-phase interference precoding matrix is different from the 2TX rank-1 full-phase interference precoding matrix initially applied to the coherent antenna group in which the added 2TX rank-1 full-phase interference precoding matrix is added to the 8TX rank-4 precoding matrix; and if there are two, three, or four added 2TX rank-1 full-phase interference precoding matrices, each of the two, three, or four added 2TX rank-1 full-phase interference precoding matrices is different.

[0319] In some embodiments, if the transmission rank is r which is greater than 4, the TPMI indicates r - 4 2TX rank-1 full-phase interference precoding matrices, and each 2TX rank-1 full-phase interference precoding matrix is added to one of the r - 4 antenna groups based on the 8TX rank-4 precoding matrix. If r is 5, one 2TX rank-1 full-phase interference precoding matrix is added to the third antenna group or the fourth antenna group. If r is 7, one 2TX rank-1 full-phase interference precoding matrix is added to the first antenna group or the second antenna group, and two 2TX rank-1 full-phase interference precoding matrices are added to the third antenna group and the fourth antenna group. Each antenna group in which a 2TX rank-1 full-phase interference precoding matrix is added transmits two data layers.

[0320] Figure 8 is a schematic block diagram illustrating an apparatus according to one embodiment.

[0321] Reference Figure 8 , the UE (i.e., the remote unit) includes a processor, a memory, and a transceiver. The processor implements Figure 6 the functions, procedures, and / or methods proposed in

[0322] The UE includes a transceiver; and a processor coupled to the transceiver, wherein the processor is configured to receive, via the transceiver, a control message that schedules a PUSCH transmission with a transmission rank N to be sent by eight antenna ports in four coherent antenna groups, wherein the control message includes a TPMI indicating an 8TX precoding matrix used by the four coherent antenna groups, and wherein N is any one of 1 to 8; and to send, via the transceiver, the scheduled PUSCH transmission according to the control message.

[0323] In some embodiments, the four coherent antenna groups are divided into two antenna group pairs, each antenna group pair consisting of two coherent antenna groups, and the TMPI indicates one or two 4TX partial interference precoding matrices, each 4TX partial interference precoding matrix being used by one of the two antenna group pairs.

[0324] In some embodiments, each 4TX partial interference precoding matrix is split into two 2TX precoding matrices, and each 2TX precoding matrix is used as the precoding matrix for one of the two coherent antenna groups in an antenna group pair using the 4TX partial interference precoding matrix. If the transmission rank is 1, one 4TX partial interference precoding matrix is a 4TX rank-1 precoding matrix and is used by an antenna group pair indicated by the TPMI. If the transmission rank is 2, both 4TX partial interference precoding matrices are 4TX rank-1 precoding matrices. If the transmission rank is 3, one of the two 4TX partial interference precoding matrices is a 4TX rank-1 precoding matrix and the other of the two 4TX partial interference precoding matrices is a 4TX rank-2 precoding matrix. If the transmission rank is 4, both 4TX partial interference precoding matrices are 4TX rank-2 precoding matrices. If the transmission rank is 5, one of the two 4TX partial interference precoding matrices is a 4TX rank-2 precoding matrix and the other of the two 4TX partial interference precoding matrices is a 4TX rank-3 precoding matrix. If the transmission rank is 6, both 4TX partial interference precoding matrices are 4TX rank-3 precoding matrices. If the transmission rank is 7, one of the two 4TX partial interference precoding matrices is a 4TX rank-3 precoding matrix and the other of the two 4TX partial interference precoding matrices is a 4TX rank-4 precoding matrix. If the transmission rank is 8, both 4TX partial interference precoding matrices are 4TX rank-4 precoding matrices.

[0325] In some embodiments, each 4TX partial interference precoding matrix is selected from all 4TX partial interference precoding matrices of an appropriate rank.

[0326] In some embodiments, at least one of the two partial interference precoding matrices is selected only from a part of the 4TX partial interference precoding matrices of an appropriate rank. Specifically, the 2TX precoding matrix of each coherent antenna group is different from the 2TX precoding matrix of any other coherent antenna group.

[0327] In some embodiments, the TPMI includes a single indication of one 4TX partial interference precoding matrix or a combination of two 4TX partial interference precoding matrices.

[0328] Alternatively, the TPMI includes a first part indicating one of two 4TX partial interference coding matrices and a second part indicating the other of the two 4TX partial interference coding matrices. Specifically, the second part indicates the other of the two 4TX partial interference coding matrices from a subset of precoding matrices of an appropriate rank based on the indication of one of the two 4TX partial interference coding matrices by the first part; or the first part indicates one of the two 4TX partial interference coding matrices from a subset of precoding matrices of an appropriate rank based on the indication of the other of the two 4TX partial interference coding matrices by the second part.

[0329] In some embodiments, depending on the antenna port number, each of the two split 2TX precoding matrices is applied to one coherent antenna group including two antenna ports.

[0330] In some embodiments, the TPMI indicates a combination of a coherent antenna group and a 2TX rank-1 full-phase precoding matrix. If the transmission rank is 1, the TMPI indicates one of the four coherent antenna groups and a 2TX rank-1 full-phase precoding matrix. If the transmission rank is 2, the TMPI indicates a combination of two of the four coherent antenna groups and a combination of two 2TX rank-1 full-phase precoding matrices. If the transmission rank is 3, the TMPI indicates a combination of three of the four coherent antenna groups and a combination of three 2TX rank-1 full-phase precoding matrices. If the transmission rank is 4, the 8TX rank-4 precoding matrix consists of four 2TX rank-1 full-phase precoding matrices, where the four 2TX rank-1 full-phase precoding matrices are applied to the four coherent antenna groups in a sequential manner. If the transmission rank is 5, the TPMI indicates which one of the third and fourth coherent antenna groups with a 2TX rank-1 full-phase precoding matrix added and which one of the four 2TX rank-1 full-phase precoding matrices is the added 2TX rank-1 full-phase precoding matrix. If the transmission rank is 6, the TPMI indicates which one of the first and second coherent antenna groups with the first 2TX rank-1 full-phase precoding matrix added and which one of the third and fourth coherent antenna groups with the second 2TX rank-1 full-phase precoding matrix added, and which one of the four 2TX rank-1 full-phase precoding matrices is the added first 2TX rank-1 full-phase precoding matrix and which one of the four 2TX rank-1 full-phase precoding matrices is the added second 2TX rank-1 full-phase precoding matrix. If the transmission rank is 7, the TPMI indicates which one of the first and second coherent antenna groups with the first 2TX rank-1 full-phase precoding matrix added, and which one of the four 2TX rank-1 full-phase precoding matrices is the added first 2TX rank-1 full-phase precoding matrix, which one of the four 2TX rank-1 full-phase precoding matrices is the second 2TX rank-1 full-phase precoding matrix added to the third coherent antenna group, and which one of the four 2TX rank-1 full-phase precoding matrices is the third 2TX rank-1 full-phase precoding matrix added to the fourth coherent antenna group. If the transmission rank is 8, the TPMI indicates which one of the four 2TX rank-1 full-phase precoding matrices is the first 2TX rank-1 full-phase precoding matrix added to the first coherent antenna group, which one of the four 2TX rank-1 full-phase precoding matrices is the second 2TX rank-1 full-phase precoding matrix added to the second coherent antenna group, which one of the four 2TX rank-1 full-phase precoding matrices is the third 2TX rank-1 full-phase precoding matrix added to the third coherent antenna group, and which one of the four 2TX rank-1 full-phase precoding matrices is the fourth 2TX rank-1 full-phase precoding matrix added to the fourth coherent antenna group.Specifically, each added 2TX rank-1 full-phase interference coding matrix is different from the 2TX rank-1 full-phase interference coding matrix initially applied to the coherent antenna group to which the added 2TX rank-1 full-phase interference coding matrix is added in the 8TX rank-4 precoding matrix; and if there are two, three, or four added 2TX rank-1 full-phase interference coding matrices, each precoding matrix among the two, three, or four added 2TX rank-1 full-phase interference coding matrices is different.

[0331] In some embodiments, if the transmission rank is r which is greater than 4, the TPMI indicates r - 4 2TX rank-1 full-phase interference coding matrices, and each 2TX rank-1 full-phase interference coding matrix is added to one of the r - 4 antenna groups based on the 8TX rank-4 precoding matrix. If r is 5, one 2TX rank-1 full-phase interference coding matrix is added to the third antenna group or the fourth antenna group. If r is 7, one 2TX rank-1 full-phase interference coding matrix is added to the first antenna group or the second antenna group, and two 2TX rank-1 full-phase interference coding matrices are added to the third antenna group and the fourth antenna group. Each antenna group in which a 2TX rank-1 full-phase interference coding matrix is added transmits two data layers.

[0332] The gNB (i.e., the base station unit) includes a processor, a memory, and a transceiver. The processor implements Figure 7 the functions, procedures, and / or methods proposed in

[0333] The base station unit includes a transceiver; and a processor coupled to the transceiver, wherein the processor is configured to send, via the transceiver, a control message that schedules a PUSCH transmission with a transmission rank N to be sent by eight antenna ports in four coherent antenna groups, wherein the control message includes a TPMI indicating the 8TX precoding matrix used by the four coherent antenna groups, and wherein N is any one of 1 to 8; and receive, via the transceiver, the transmitted PUSCH transmission scheduled according to the control message.

[0334] In some embodiments, the four coherent antenna groups are divided into two antenna group pairs, each antenna group pair consisting of two coherent antenna groups, and the TMPI indicates one or two 4TX partial interference coding matrices, and each 4TX partial interference coding matrix is used by one of the two antenna group pairs.

[0335] In some embodiments, each 4TX partial interference precoding matrix is split into two 2TX precoding matrices, and each 2TX precoding matrix is used as the precoding matrix for one of the two coherent antenna groups in an antenna group pair using the 4TX partial interference precoding matrix. If the transmission rank is 1, one 4TX partial interference precoding matrix is a 4TX rank-1 precoding matrix and is used by an antenna group pair indicated by the TPMI. If the transmission rank is 2, both 4TX partial interference precoding matrices are 4TX rank-1 precoding matrices. If the transmission rank is 3, one of the two 4TX partial interference precoding matrices is a 4TX rank-1 precoding matrix and the other of the two 4TX partial interference precoding matrices is a 4TX rank-2 precoding matrix. If the transmission rank is 4, both 4TX partial interference precoding matrices are 4TX rank-2 precoding matrices. If the transmission rank is 5, one of the two 4TX partial interference precoding matrices is a 4TX rank-2 precoding matrix and the other of the two 4TX partial interference precoding matrices is a 4TX rank-3 precoding matrix. If the transmission rank is 6, both 4TX partial interference precoding matrices are 4TX rank-3 precoding matrices. If the transmission rank is 7, one of the two 4TX partial interference precoding matrices is a 4TX rank-3 precoding matrix and the other of the two 4TX partial interference precoding matrices is a 4TX rank-4 precoding matrix. If the transmission rank is 8, both 4TX partial interference precoding matrices are 4TX rank-4 precoding matrices.

[0336] In some embodiments, each 4TX partial interference precoding matrix is selected from all 4TX partial interference precoding matrices of an appropriate rank.

[0337] In some embodiments, at least one of the two partial interference precoding matrices is selected only from a part of the 4TX partial interference precoding matrices of an appropriate rank. Specifically, the 2TX precoding matrix of each coherent antenna group is different from the 2TX precoding matrix of any other coherent antenna group.

[0338] In some embodiments, the TPMI includes a single indication of a combination of one 4TX partial interference precoding matrix or two 4TX partial interference precoding matrices.

[0339] Alternatively, the TPMI includes a first part indicating one of two 4TX partial interference coding matrices and a second part indicating the other of the two 4TX partial interference coding matrices. Specifically, the second part indicates the other of the two 4TX partial interference coding matrices from a subset of precoding matrices of an appropriate rank based on the indication of one of the two 4TX partial interference coding matrices by the first part; or the first part indicates one of the two 4TX partial interference coding matrices from a subset of precoding matrices of an appropriate rank based on the indication of the other of the two 4TX partial interference coding matrices by the second part.

[0340] In some embodiments, depending on the antenna port number, each of the two split 2TX precoding matrices is applied to a coherent antenna group including two antenna ports.

[0341] In some embodiments, the TPMI indicates a combination of a coherent antenna group and a 2TX rank-1 full-phase precoding matrix. If the transmission rank is 1, the TMPI indicates one of four coherent antenna groups and a 2TX rank-1 full-phase precoding matrix. If the transmission rank is 2, the TMPI indicates a combination of two of the four coherent antenna groups and a combination of two 2TX rank-1 full-phase precoding matrices. If the transmission rank is 3, the TMPI indicates a combination of three of the four coherent antenna groups and a combination of three 2TX rank-1 full-phase precoding matrices. If the transmission rank is 4, the 8TX rank-4 precoding matrix is composed of four 2TX rank-1 full-phase precoding matrices, where the four 2TX rank-1 full-phase precoding matrices are applied to the four coherent antenna groups in a sequential manner. If the transmission rank is 5, the TPMI indicates which one of the third and fourth coherent antenna groups with a 2TX rank-1 full-phase precoding matrix added and which one of the four 2TX rank-1 full-phase precoding matrices is the added 2TX rank-1 full-phase precoding matrix. If the transmission rank is 6, the TPMI indicates which one of the first and second coherent antenna groups with the first 2TX rank-1 full-phase precoding matrix added and which one of the third and fourth coherent antenna groups with the second 2TX rank-1 full-phase precoding matrix added, and which one of the four 2TX rank-1 full-phase precoding matrices is the added first 2TX rank-1 full-phase precoding matrix and which one of the four 2TX rank-1 full-phase precoding matrices is the added second 2TX rank-1 full-phase precoding matrix. If the transmission rank is 7, the TPMI indicates which one of the first and second coherent antenna groups with the first 2TX rank-1 full-phase precoding matrix added, and which one of the four 2TX rank-1 full-phase precoding matrices is the added first 2TX rank-1 full-phase precoding matrix, which one of the four 2TX rank-1 full-phase precoding matrices is the second 2TX rank-1 full-phase precoding matrix added to the third coherent antenna group, and which one of the four 2TX rank-1 full-phase precoding matrices is the third 2TX rank-1 full-phase precoding matrix added to the fourth coherent antenna group. If the transmission rank is 8, the TPMI indicates which one of the four 2TX rank-1 full-phase precoding matrices is the first 2TX rank-1 full-phase precoding matrix added to the first coherent antenna group, which one of the four 2TX rank-1 full-phase precoding matrices is the second 2TX rank-1 full-phase precoding matrix added to the second coherent antenna group, which one of the four 2TX rank-1 full-phase precoding matrices is the third 2TX rank-1 full-phase precoding matrix added to the third coherent antenna group, and which one of the four 2TX rank-1 full-phase precoding matrices is the fourth 2TX rank-1 full-phase precoding matrix added to the fourth coherent antenna group.Specifically, each added 2TX rank-1 full-phase interference precoding matrix is different from the 2TX rank-1 full-phase interference precoding matrix initially applied to the coherent antenna group to which the added 2TX rank-1 full-phase interference precoding matrix is added in the 8TX rank-4 precoding matrix; and if there are two, three, or four added 2TX rank-1 full-phase interference precoding matrices, each precoding matrix among the two, three, or four added 2TX rank-1 full-phase interference precoding matrices is different.

[0342] In some embodiments, if the transmission rank is r which is greater than 4, the TPMI indicates r - 4 2TX rank-1 full-phase interference precoding matrices, and each 2TX rank-1 full-phase interference precoding matrix is added to one of the r - 4 antenna groups based on the 8TX rank-4 precoding matrix. If r is 5, one 2TX rank-1 full-phase interference precoding matrix is added to the third antenna group or the fourth antenna group. If r is 7, one 2TX rank-1 full-phase interference precoding matrix is added to the first antenna group or the second antenna group, and two 2TX rank-1 full-phase interference precoding matrices are added to the third antenna group and the fourth antenna group. Each antenna group to which one 2TX rank-1 full-phase interference precoding matrix is added transmits two data layers.

[0343] The processor may implement each layer of the radio interface protocol. The memory is connected to the processor to store various information for driving the processor. The transceiver is connected to the processor to transmit and / or receive radio signals. Needless to say, the transceiver may be implemented as a transmitter for transmitting radio signals and a receiver for receiving radio signals.

[0344] The memory may be located inside or outside the processor and is connected to the processor by various well-known means.

[0345] In the above embodiments, the components and features of the embodiments are combined in a predetermined form. Unless otherwise clearly stated, each component or feature should be regarded as an option. Each component or feature may be implemented without being associated with other components or features. In addition, embodiments may be configured by associating some components and / or features. The order of operations described in the embodiments may be changed. Some components or features of any embodiment may be included in another embodiment or replaced with components and features corresponding to another embodiment. Obviously, claim combinations not explicitly recited in the claims are formed into embodiments or included in new claims.

[0346] Embodiments can be implemented by hardware, firmware, software, or a combination thereof. In the case of implementation by hardware, according to the hardware implementation, the exemplary embodiments described herein can be implemented by using one or more application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), processors, controllers, microcontrollers, microprocessors, etc.

[0347] The embodiments can be practiced in other specific forms. The described embodiments are to be considered in all respects only as illustrative and not restrictive. Thus, the scope of the present invention is indicated by the appended claims rather than the foregoing description. All changes that come within the meaning and range of equivalency of the claims are to be embraced within their scope.

Claims

1. A user equipment (UE) comprising: A transceiver; And A processor coupled to the transceiver, wherein the processor is configured to Receive, via the transceiver, a control message that schedules a PUSCH transmission with a transmission rank N to be sent by eight antenna ports in four coherent antenna groups, wherein the control message includes a TPMI indicating an 8TX precoding matrix used by the four coherent antenna groups, and wherein N is any one of 1 to 8; and Send, via the transceiver, the scheduled PUSCH transmission according to the control message.

2. The UE according to claim 1, wherein The four coherent antenna groups are divided into two antenna group pairs, each antenna group pair of the two antenna group pairs being composed of two coherent antenna groups, and The TMPI indicates one or two 4TX partial precoding matrices, each 4TX partial precoding matrix of the one or two 4TX partial precoding matrices being used by one of the two antenna group pairs.

3. The UE according to claim 2, wherein, Each 4TX partial precoding matrix is split into two 2TX precoding matrices, each 2TX precoding matrix of the two 2TX precoding matrices being used as a precoding matrix for one of the two coherent antenna groups in the antenna group pair using the 4TX partial precoding matrix.

4. The UE according to claim 3, wherein If the transmission rank is 1, one 4TX partial precoding matrix is a 4TX rank 1 precoding matrix and is used by one antenna group pair indicated by the TPMI; If the transmission rank is 2, both 4TX partial precoding matrices are 4TX rank 1 precoding matrices; If the transmission rank is 3, one of the two 4TX partial precoding matrices is a 4TX rank 1 precoding matrix and the other of the two 4TX partial precoding matrices is a 4TX rank 2 precoding matrix; If the transmission rank is 4, both 4TX partial precoding matrices are 4TX rank 2 precoding matrices; If the transmission rank is 5, one of the two 4TX partial precoding matrices is a 4TX rank 2 precoding matrix and the other of the two 4TX partial precoding matrices is a 4TX rank 3 precoding matrix; If the transmission rank is 6, both 4TX partial precoding matrices are 4TX rank 3 precoding matrices; If the transmission rank is 7, one of the two 4TX partial precoding matrices is a 4TX rank 3 precoding matrix and the other of the two 4TX partial precoding matrices is a 4TX rank 4 precoding matrix; and If the transmission rank is 8, both 4TX partial precoding matrices are 4TX rank 4 precoding matrices.

5. The UE according to claim 2, wherein, Each 4TX partial precoding matrix is selected from all 4TX partial precoding matrices of the appropriate rank.

6. The UE according to claim 2, wherein, At least one of the two partial precoding matrices is selected only from a part of the 4TX partial precoding matrices of the appropriate rank.

7. The UE according to claim 6, wherein, The 2TX precoding matrix of each coherent antenna group is different from the 2TX precoding matrix of any other coherent antenna group.

8. The UE according to claim 2, wherein, The TPMI includes a single indication of a 4TX partial precoding matrix or a combination of two 4TX partial precoding matrices.

9. The UE according to claim 2, wherein, The TPMI includes a first part indicating one of the two 4TX partial precoding matrices and a second part indicating the other of the two 4TX partial precoding matrices.

10. The UE according to claim 9, wherein, The second part indicates the other of the two 4TX partial precoding matrices from a subset of precoding matrices of an appropriate rank based on the indication by the first part of one of the two 4TX partial precoding matrices, or the first part indicates one of the two 4TX partial precoding matrices from a subset of precoding matrices of an appropriate rank based on the indication by the second part of the other of the two 4TX partial precoding matrices.

11. The UE according to claim 3, wherein, Depending on the antenna port number, each of the two split 2TX precoding matrices is applied to a coherent antenna group including two antenna ports.

12. The UE according to claim 1, wherein, The TPMI indicates a combination of a coherent antenna group and a 2TX rank-1 full precoding matrix.

13. The UE according to claim 12, wherein, If the transmission rank is 1, the TMPI indicates one antenna group among the four coherent antenna groups and a 2TX rank-1 full precoding matrix; If the transmission rank is 2, the TMPI indicates a combination of two coherent antenna groups among the four coherent antenna groups and a combination of two 2TX rank-1 full precoding matrices; If the transmission rank is 3, the TMPI indicates a combination of three coherent antenna groups among the four coherent antenna groups and a combination of three 2TX rank-1 full precoding matrices; If the transmission rank is 4, the 8TX rank-4 precoding matrix is composed of four 2TX rank-1 full precoding matrices, wherein the four 2TX rank-1 full precoding matrices are applied to the four coherent antenna groups in a sequential manner; If the transmission rank is 5, the TPMI indicates one antenna group among the third and fourth coherent antenna groups with a 2TX rank-1 full precoding matrix added and which one of the four 2TX rank-1 full precoding matrices is the added 2TX rank-1 full precoding matrix; If the transmission rank is 6, the TPMI indicates one antenna group among the first and second coherent antenna groups with a first 2TX rank-1 full precoding matrix added and one antenna group among the third and fourth coherent antenna groups with a second 2TX rank-1 full precoding matrix added, and which one of the four 2TX rank-1 full precoding matrices is the added first 2TX rank-1 full precoding matrix and which one of the four 2TX rank-1 full precoding matrices is the added second 2TX rank-1 full precoding matrix; If the transmission rank is 7, the TPMI indicates one of the first coherent antenna group and the second coherent antenna group to which the first 2TX rank-1 full-phase precoding matrix is added, which one of the four 2TX rank-1 full-phase precoding matrices is the added first 2TX rank-1 full-phase precoding matrix, which one of the four 2TX rank-1 full-phase precoding matrices is the second 2TX rank-1 full-phase precoding matrix added to the third coherent antenna group, and which one of the four 2TX rank-1 full-phase precoding matrices is the third 2TX rank-1 full-phase precoding matrix added to the fourth coherent antenna group; and If the transmission rank is 8, the TPMI indicates which one of the four 2TX rank-1 full-phase precoding matrices is the first 2TX rank-1 full-phase precoding matrix added to the first coherent antenna group, which one of the four 2TX rank-1 full-phase precoding matrices is the second 2TX rank-1 full-phase precoding matrix added to the second coherent antenna group, which one of the four 2TX rank-1 full-phase precoding matrices is the third 2TX rank-1 full-phase precoding matrix added to the third coherent antenna group, and which one of the four 2TX rank-1 full-phase precoding matrices is the fourth 2TX rank-1 full-phase precoding matrix added to the fourth coherent antenna group.

14. The UE according to claim 13, wherein, Among them, each added 2TX rank-1 full-phase precoding matrix is different from the 2TX rank-1 full-phase precoding matrix initially applied to the coherent antenna group to which the added 2TX rank-1 full-phase precoding matrix is added in the 8TX rank-4 precoding matrix; and if there are two, three, or four added 2TX rank-1 full-phase precoding matrices, each 2TX rank-1 full-phase precoding matrix among the two, three, or four added 2TX rank-1 full-phase precoding matrices is different.

15. The UE according to claim 12, wherein, if the transmission rank is r greater than 4, the TPMI indicates r - 4 2TX rank-1 full-phase precoding matrices, and each of the r - 4 2TX rank-1 full-phase precoding matrices is added to one of the r - 4 antenna groups based on the 8TX rank-4 precoding matrix.

16. The UE according to claim 15, wherein, if r is 5, one 2TX rank-1 full-phase precoding matrix is added to the third antenna group or the fourth antenna group; and if r is 7, one 2TX rank-1 full-phase precoding matrix is added to the first antenna group or the second antenna group, and two 2TX rank-1 full-phase precoding matrices are added to the third antenna group and the fourth antenna group.

17. The UE according to claim 15, wherein, each antenna group to which one 2TX rank-1 full-phase precoding matrix is added transmits two data layers.

18. A method performed at a user equipment (UE), comprising: Receive a control message that schedules a PUSCH transmission with a transmission rank N to be sent by eight antenna ports in four coherent antenna groups, where the control message includes a TPMI indicating an 8TX precoding matrix used by the four coherent antenna groups, and where N is any one of 1 to 8; and Transmit the scheduled PUSCH transmission according to the control message.

19. A base station unit, comprising: A transceiver; And A processor coupled to the transceiver, where the processor is configured to transmit, via the transceiver, a control message that schedules a PUSCH transmission with a transmission rank N to be sent by eight antenna ports in four coherent antenna groups, where the control message includes a TPMI indicating an 8TX precoding matrix used by the four coherent antenna groups, and where N is any one of 1 to 8; and Receive, via the transceiver, the scheduled PUSCH transmission sent according to the control message.

20. The base station unit according to claim 19, where The four coherent antenna groups are divided into two antenna group pairs, each of the two antenna group pairs consisting of two coherent antenna groups, and The TMPI indicates one or two 4TX partial precoding matrices, each of the one or two 4TX partial precoding matrices being used by one of the two antenna group pairs.

21. The base station unit according to claim 20, wherein, Each 4TX partial precoding matrix is split into two 2TX precoding matrices, each of the two 2TX precoding matrices being used as a precoding matrix for one of the two coherent antenna groups in the antenna group pair using the 4TX partial precoding matrix.

22. The base station unit according to claim 21, where If the transmission rank is 1, one 4TX partial precoding matrix is a 4TX rank-1 precoding matrix and is used by one of the antenna group pairs indicated by the TPMI; If the transmission rank is 2, both 4TX partial precoding matrices are 4TX rank-1 precoding matrices; If the transmission rank is 3, one of the two 4TX partial precoding matrices is a 4TX rank-1 precoding matrix and the other of the two 4TX partial precoding matrices is a 4TX rank-2 precoding matrix; If the transmission rank is 4, both 4TX partial precoding matrices are 4TX rank-2 precoding matrices; If the transmission rank is 5, one of the two 4TX partial precoding matrices is a 4TX rank-2 precoding matrix and the other of the two 4TX partial precoding matrices is a 4TX rank-3 precoding matrix; If the transmission rank is 6, both 4TX partial precoding matrices are 4TX rank-3 precoding matrices; If the transmission rank is 7, one of the two 4TX partial interference precoding matrices is a 4TX rank-3 precoding matrix and the other of the two 4TX partial interference precoding matrices is a 4TX rank-4 precoding matrix; and If the transmission rank is 8, both of the two 4TX partial interference precoding matrices are 4TX rank-4 precoding matrices.

23. The base station unit according to claim 20, wherein, Each 4TX partial interference precoding matrix is selected from all 4TX partial interference precoding matrices of an appropriate rank.

24. The base station unit according to claim 20, wherein, At least one of the two partial interference precoding matrices is selected only from a part of the 4TX partial interference precoding matrices of an appropriate rank.

25. The base station unit according to claim 24, wherein, The 2TX precoding matrix of each coherent antenna group is different from the 2TX precoding matrix of any other coherent antenna group.

26. The base station unit according to claim 20, wherein, The TPMI includes a single indication of a 4TX partial interference precoding matrix or a combination of two 4TX partial interference precoding matrices.

27. The base station unit according to claim 20, wherein, The TPMI includes a first part indicating one of the two 4TX partial interference precoding matrices and a second part indicating the other of the two 4TX partial interference precoding matrices.

28. The base station unit according to claim 27, wherein, The second part indicates the other of the two 4TX partial interference precoding matrices from a subset of precoding matrices of an appropriate rank based on the indication by the first part of one of the two 4TX partial interference precoding matrices, or the first part indicates one of the two 4TX partial interference precoding matrices from a subset of precoding matrices of an appropriate rank based on the indication by the second part of the other of the two 4TX partial interference precoding matrices.

29. The base station unit according to claim 21, wherein Depending on the antenna port number, each of the two split 2TX precoding matrices is applied to a coherent antenna group including two antenna ports.

30. The base station unit according to claim 19, wherein, The TPMI indicates a combination of a coherent antenna group and a 2TX rank-1 full interference precoding matrix.

31. The base station unit according to claim 30, wherein, If the transmission rank is 1, the TMPI indicates one of the four coherent antenna groups and a 2TX rank-1 full interference precoding matrix; If the transmission rank is 2, the TMPI indicates a combination of two of the four coherent antenna groups and a combination of two 2TX rank-1 full interference precoding matrices; If the transmission rank is 3, the TMPI indicates a combination of three of the four coherent antenna groups and a combination of three 2TX rank-1 full interference precoding matrices; If the transmission rank is 4, the 8TX rank-4 precoding matrix is composed of four 2TX rank-1 full interference precoding matrices, wherein the four 2TX rank-1 full interference precoding matrices are applied to the four coherent antenna groups in a sequential manner; If the transmission rank is 5, the TPMI indicates one of the third and fourth coherent antenna groups to which a 2TX rank-1 full interference precoding matrix is added and which one of the four 2TX rank-1 full interference precoding matrices is the added 2TX rank-1 full interference precoding matrix; If the transmission rank is 6, the TPMI indicates one antenna group among the first coherent antenna group and the second coherent antenna group to which the first 2TX rank-1 full-phase interference cancellation coding matrix is added, and one antenna group among the third coherent antenna group and the fourth coherent antenna group to which the second 2TX rank-1 full-phase interference cancellation coding matrix is added, and which one of the four 2TX rank-1 full-phase interference cancellation coding matrices is the added first 2TX rank-1 full-phase interference cancellation coding matrix and which one of the four 2TX rank-1 full-phase interference cancellation coding matrices is the added second 2TX rank-1 full-phase interference cancellation coding matrix; If the transmission rank is 7, the TPMI indicates one antenna group among the first coherent antenna group and the second coherent antenna group to which the first 2TX rank-1 full-phase interference cancellation coding matrix is added, and which one of the four 2TX rank-1 full-phase interference cancellation coding matrices is the added first 2TX rank-1 full-phase interference cancellation coding matrix, which one of the four 2TX rank-1 full-phase interference cancellation coding matrices is the second 2TX rank-1 full-phase interference cancellation coding matrix added to the third coherent antenna group, and which one of the four 2TX rank-1 full-phase interference cancellation coding matrices is the third 2TX rank-1 full-phase interference cancellation coding matrix added to the fourth coherent antenna group; and If the transmission rank is 8, the TPMI indicates which one of the four 2TX rank-1 full-phase interference cancellation coding matrices is the first 2TX rank-1 full-phase interference cancellation coding matrix added to the first coherent antenna group, which one of the four 2TX rank-1 full-phase interference cancellation coding matrices is the second 2TX rank-1 full-phase interference cancellation coding matrix added to the second coherent antenna group, which one of the four 2TX rank-1 full-phase interference cancellation coding matrices is the third 2TX rank-1 full-phase interference cancellation coding matrix added to the third coherent antenna group, and which one of the four 2TX rank-1 full-phase interference cancellation coding matrices is the fourth 2TX rank-1 full-phase interference cancellation coding matrix added to the fourth coherent antenna group.

32. The base station unit according to claim 31, wherein, Among them, each added 2TX rank-1 full-phase interference cancellation coding matrix is different from the 2TX rank-1 full-phase interference cancellation coding matrix originally applied to the coherent antenna group to which the added 2TX rank-1 full-phase interference cancellation coding matrix is added in the 8TX rank-4 precoding matrix; and if there are two, three or four added 2TX rank-1 full-phase interference cancellation coding matrices, each 2TX rank-1 full-phase interference cancellation coding matrix among the two, three or four added 2TX rank-1 full-phase interference cancellation coding matrices is different.

33. The base station unit according to claim 30, wherein, if the transmission rank is r greater than 4, the TPMI indicates r-4 2TX rank-1 full-phase interference cancellation coding matrices, and each 2TX rank-1 full-phase interference cancellation coding matrix is added to one antenna group among r-4 antenna groups based on the 8TX rank-4 precoding matrix.

34. The base station unit according to claim 33, wherein, if r is 5, one 2TX rank-1 full-phase interference cancellation coding matrix is added to the third antenna group or the fourth antenna group; and If r is 7, a 2TX rank-1 full-phase interference coding matrix is added to the first antenna group or the second antenna group, and two 2TX rank-1 full-phase interference coding matrixes are added to the third antenna group and the fourth antenna group.

35. The base station unit according to claim 33, wherein Each antenna group in the antenna group to which a 2TX rank-1 full-phase interference coding matrix is added transmits two data layers.

36. A method performed at a base station unit, comprising: Transmitting a control message that schedules a PUSCH transmission with a transmission rank N to be transmitted by eight antenna ports in four coherent antenna groups, wherein the control message includes a TPMI indicating an 8TX precoding matrix used by the four coherent antenna groups, and wherein N is any one of 1 to 8; and Receiving the scheduled PUSCH transmission transmitted according to the control message.

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