PUSCH TRANSMISSION FOR PARTIALLY COHERENT UE WITH Eight ANTENNA PORTS

Abstract

Methods and apparatus are disclosed for PUSCH transmission for a partially coherent UE utilizing eight antenna ports. In one embodiment, a UE comprises: a transceiver; in one embodiment, an apparatus includes a transceiver, and a processor coupled to the transceiver, where the processor is configured to receive, via the transceiver, a DCI scheduling a PUSCH, where the DCI includes an antenna port field indicating a number of DMRS ports, the number of DMRS ports determining a rank of the scheduled PUSCH, and the DCI further includes a TPMI field indicating one or two precoding matrices; and determining a precoding matrix for the scheduled PUSCH according to the rank and the one or two precoding matrices.

Description

Technical Field

[0001] The subject matter disclosed herein relates generally to wireless communications and, more particularly, to methods and apparatus for PUSCH transmission for partially coherent UEs utilizing 8 antenna ports. Background Art

[0002] The following abbreviations are defined herein, at least some of which are referred to in the following description: New Radio (NR), Very Large Scale Integration (VLSI), Random Access Memory (RAM), Read Only Memory (ROM), Erasable Programmable Read Only Memory (EPROM or Flash), Compact Disc Read Only Memory (CD-ROM), Local Area Network (LAN), Wide Area Network (WAN), User Equipment (UE), Evolved Node B (eNB), Next Generation Node B (gNB), Uplink (UL), Downlink (DL), Central Processing Unit (CPU), Graphics Processing Unit (GPU), Field Field Programmable Gate Array (FPGA), Orthogonal Frequency Division Multiplexing (OFDM), Radio Resource Control (RRC), User Entity / Equipment (Mobile Terminal), Transmitter (TX), Receiver (RX), Physical Uplink Shared Channel (PUSCH), Codebook (CB), Non-Codebook (nCB), Sounding Reference Signal (SRS), Bandwidth Part (BWP), Channel State Information Reference Signal (CSI-RS), Downlink Control Information (DCI), Transmit Precoding Matrix Indicator (TPMI), Transmit Rank Index (TRI), Codeword (CW), Demodulation Reference Signal (DMRS).

[0003] For advanced UEs equipped with 8 antennas with one or more layers, PUSCH transmission with 8 antenna ports (8Tx PUSCH) shall be supported in NR Release 18.

[0004] The present disclosure is directed to PUSCH transmission for partially coherent UEs utilizing 8 antenna ports. Summary of the invention

[0005] Methods and apparatus for PUSCH transmission utilizing 8 antenna ports for partially coherent UEs are disclosed.

[0006] In one embodiment, a UE includes: a transceiver; and a processor coupled to the transceiver, wherein the processor is configured to receive, via the transceiver, a DCI for scheduling a PUSCH, wherein the DCI includes an antenna port field indicating a number of DMRS ports, the number of DMRS ports determining a rank of the scheduled PUSCH, and the DCI further includes a TPMI field indicating one or two precoding matrices; and determine a precoding matrix for the scheduled PUSCH based on the rank and the one or two precoding matrices.

[0007] In a certain embodiment, the processor is further configured to report the number of antenna groups (Ng) via the transceiver.

[0008] In some embodiment, the processor is further configured to determine the bit width of the TPMI field according to a maximum rank having a value of 1, 4, or 8.

[0009] In a certain embodiment, when a rank-1, rank-2, or rank-3 PUSCH is scheduled for a UE with Ng=4, the TPMI field indicates the antenna group by which each PUSCH layer is transmitted by an antenna port from the antenna group.

[0010] In a certain embodiment, when a rank-4, rank-5, rank-6, rank-7, or rank-8 PUSCH is scheduled for a UE with Ng=4, it is predetermined by which antenna port from which antenna group each PUSCH layer is transmitted. In particular, when a rank 4 PUSCH is scheduled for a UE with Ng=4, the first PUSCH layer is sent by the antenna port from the first antenna group, the second PUSCH layer is sent by the antenna port from the second antenna group, the third PUSCH layer is sent by the antenna port from the third antenna group, and the fourth PUSCH layer is sent by the antenna port from the fourth antenna group; when a rank 5 PUSCH is scheduled for a UE with Ng=4, the first PUSCH layer is sent by the antenna port from the first antenna group, the second PUSCH layer is sent by the antenna port from the second antenna group, the third PUSCH layer and the fourth PUSCH layer are sent by the antenna port from the third antenna group, and the fifth PUSCH layer is sent by the antenna port from the fourth antenna group; when a rank 6 PUSCH is scheduled for a UE with Ng=4, the first PUSCH layer and the second PUSCH layer are sent by the antenna port from the first antenna group, the third PUSCH layer is sent by the antenna port from the second antenna group, the fourth PUSCH layer and the fifth PUSCH layer are sent by the antenna port from the fourth antenna group. The PUSCH layer is transmitted by the antenna port from the third antenna group, and the sixth PUSCH layer is transmitted by the antenna port from the fourth antenna group; when the UE scheduling rank 7 PUSCH with Ng=4, the first PUSCH layer and the second PUSCH layer are transmitted by the antenna port from the first antenna group, the third PUSCH layer is transmitted by the antenna port from the second antenna group, the fourth PUSCH layer and the fifth PUSCH layer are transmitted by the antenna port from the third antenna group, and the sixth PUSCH layer and the seventh PUSCH layer are transmitted by the antenna port from the fourth antenna group; and when the UE scheduling rank 8 PUSCH with Ng=4, the first PUSCH layer and the second PUSCH layer are transmitted by the antenna port from the first antenna group, the third PUSCH layer and the fourth PUSCH layer are transmitted by the antenna port from the second antenna group, the fifth PUSCH layer and the sixth PUSCH layer are transmitted by the antenna port from the third antenna group, and the seventh PUSCH layer and the eighth PUSCH layer are transmitted by the antenna port from the fourth antenna group.

[0011] In a certain embodiment, when a rank-1 PUSCH is scheduled for a UE with Ng=2, the TPMI field indicates the antenna group by which a single PUSCH layer is transmitted by antenna ports from that antenna group.

[0012] In a certain embodiment, when a rank-2, rank-3, rank-4, rank-5, rank-6, rank-7, or rank-8 PUSCH is scheduled for a UE with Ng=2, it is predetermined by which antenna port from which antenna group each PUSCH layer is transmitted. In particular, when the UE with Ng=2 schedules a rank 2 PUSCH, the first PUSCH layer is sent by the antenna port from the first antenna group, and the second PUSCH layer is sent by the antenna port from the second antenna group; when the UE with Ng=2 schedules a rank 3 PUSCH, the first PUSCH layer is sent by the antenna port from the first antenna group, and the second PUSCH layer and the third PUSCH layer are sent by the antenna port from the second antenna group; when the UE with Ng=2 schedules a rank 4 PUSCH, the first PUSCH layer and the second PUSCH layer are sent by the antenna port from the first antenna group, and the third PUSCH layer and the fourth PUSCH layer are sent by the antenna port from the second antenna group; when the UE with Ng=2 schedules a rank 5 PUSCH, the first PUSCH layer and the second PUSCH layer are sent by the antenna port from the first antenna group, and the third PUSCH layer, the fourth PUSCH layer and the fifth PUSCH layer are sent by the antenna port from the second antenna group; when Ng=2 schedules a rank 5 PUSCH, the first PUSCH layer and the second PUSCH layer are sent by the antenna port from the first antenna group, and the third PUSCH layer, the fourth PUSCH layer and the fifth PUSCH layer are sent by the antenna port from the second antenna group; =2 for UE scheduling rank 6 PUSCH, the first PUSCH layer, the second PUSCH layer and the third PUSCH layer are sent by the antenna ports from the first antenna group, and the fourth PUSCH layer, the fifth PUSCH layer and the sixth PUSCH layer are sent by the antenna ports from the second antenna group; when the UE scheduling rank 7 PUSCH with Ng=2, the first PUSCH layer, the second PUSCH layer and the third PUSCH layer are sent by the antenna ports from the first antenna group, and the fourth PUSCH layer, the fifth PUSCH layer, the sixth PUSCH layer and the seventh PUSCH layer are sent by the antenna ports from the second antenna group; and when the UE scheduling rank 8 PUSCH with Ng=2, the first PUSCH layer, the second PUSCH layer, the third PUSCH layer and the fourth PUSCH layer are sent by the antenna ports from the first antenna group, and the fifth PUSCH layer, the sixth PUSCH layer, the seventh PUSCH layer and the eighth PUSCH layer are sent by the antenna ports from the second antenna group.

[0013] In another embodiment, a method performed at a UE includes: receiving a DCI for scheduling a PUSCH, wherein the DCI includes an antenna port field indicating a number of DMRS ports, the number of DMRS ports determines a rank of the scheduled PUSCH, and the DCI further includes a TPMI field indicating one or two precoding matrices; and determining a precoding matrix for the scheduled PUSCH based on the rank and the one or two precoding matrices.

[0014] In yet another embodiment, a base station unit includes: a transceiver; and a processor coupled to the transceiver, wherein the processor is configured to send a DCI for scheduling a PUSCH via the transceiver, wherein the DCI includes an antenna port field indicating a number of DMRS ports, the number of DMRS ports determines a rank of the scheduled PUSCH, and the DCI further includes a TPMI field indicating one or two precoding matrices; and determine a precoding matrix for the scheduled PUSCH based on the rank and the one or two precoding matrices.

[0015] In yet another embodiment, a method performed at a base station unit includes: sending a DCI for scheduling a PUSCH, wherein the DCI includes an antenna port field indicating a number of DMRS ports, the number of DMRS ports determines a rank of the scheduled PUSCH, and the DCI further includes a TPMI field indicating one or two precoding matrices; and determining a precoding matrix for the scheduled PUSCH based on the rank and the one or two precoding matrices. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] A more particular description of the embodiments briefly described above will be rendered by reference to specific embodiments illustrated in the accompanying drawings. Understanding that these drawings depict only some embodiments and are therefore not to be considered limiting in scope, the embodiments will be described and explained with additional particularity and detail through the use of the accompanying drawings, in which:

[0017] Figure 1 illustrates several antenna arrangements with different numbers of antenna groups;

[0018] Figure 2 Examples of antenna layout 1-a and antenna layout 1-b are shown;

[0019] Figure 3 Examples of antenna layout 2-a and antenna layout 2-b are shown;

[0020] Figure 4 Examples of antenna layout 3-a and antenna layout 3-b are shown;

[0021] Figure 5 is a schematic flow chart illustrating an embodiment of a method;

[0022] Figure 6 is a schematic flow chart illustrating an embodiment of another method; and

[0023] Figure 7 is a schematic block diagram illustrating an apparatus according to one embodiment. DETAILED DESCRIPTION

[0024] As will be appreciated by those skilled in the art, certain aspects of the embodiments may be embodied as systems, devices, methods or program products. Therefore, the embodiments may take the form of full hardware embodiments, full software embodiments (including firmware, resident software, microcode, etc.) or embodiments combining software aspects and hardware aspects, which may be generally referred to herein as "circuits", "modules" or "systems". In addition, the embodiments may take the form of program products 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-temporary and / or non-transmitting. The storage device may not embody a signal. In a certain embodiment, the storage device employs signals only for accessing the code.

[0025] Certain functional units described in this specification may be labeled as "modules" to more particularly emphasize their independent implementation. For example, a module may be implemented as a hardware circuit including 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 using programmable hardware devices such as field programmable gate arrays, programmable array logic, programmable logic devices, etc.

[0026] Modules can also be implemented with codes and / or software for being run by various types of processors. The identification module of the code can, for example, include one or more physical or logical blocks of executable code, which can, for example, be organized as an object, process or function. However, the executable files of the identification module do not need to be physically located together, but can include fundamentally different instructions stored in different locations, which, when logically joined together, include the module and realize the intended purpose of the module.

[0027] In fact, a module of code may contain a single instruction or many instructions, and may even be distributed over several different code segments, distributed among different programs, and distributed across several memory devices. Similarly, operational data may be identified and illustrated herein within a module, and may be embodied and organized in any suitable form within any suitable type of data structure. This operational data may be collected as a single data set, or may be distributed over different locations, including over different computer-readable storage devices. Where a module or portions of a module are implemented in software, the software portions are stored on one or more computer-readable storage devices.

[0028] Any combination of one or more computer readable media may be utilized. The computer readable medium may be a computer readable storage medium. The computer readable storage medium may be a storage device storing code. The storage device may be, for example but need not be, an electronic, magnetic, optical, electromagnetic, infrared, holographic, micromechanical, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing.

[0029] A non-exhaustive list of more specific examples of storage devices would include the following: an electrical connection having one or more conductors, 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 disk 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 conjunction with an instruction execution system, apparatus, or device.

[0030] The code for carrying out the operation of the embodiments may include any number of lines and may be written in any combination of one or more programming languages, including object-oriented programming languages ​​such as Python, Ruby, Java, Smalltalk, C++, and the like, as well as conventional procedural programming languages ​​such as the "C" programming language, and / or machine languages ​​such as assembly languages. The code may be run entirely on the user's computer, partially on the user's computer, 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 may 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 may be made to an external computer (e.g., over the Internet using an Internet service provider).

[0031] References to "one embodiment", "embodiment" or similar language throughout this specification mean that a particular feature, structure or characteristic described in conjunction with the embodiment is included in at least one embodiment. Therefore, unless otherwise expressly specified, the phrases "in one embodiment", "in an embodiment" or similar language throughout this specification may, but not necessarily, refer to the same embodiment, but mean "one or more but not all embodiments". Unless otherwise expressly specified, the terms "include", "comprising", "having" and variations thereof mean "including but not limited to". Unless otherwise expressly specified, an enumerated list of items does not imply that any or all items are mutually exclusive. Unless otherwise expressly specified, the terms "one", "an" and "the" also refer to "one or more".

[0032] In addition, the features, structures or characteristics of the various embodiments described may be combined in any suitable manner. In the following description, many 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 embodiments may be practiced without one or more specific details or with other methods, components, materials, etc. In other instances, known structures, materials or operations are not shown or described in detail to avoid any confusion in various aspects of the embodiments.

[0033] Various aspects of different embodiments are described below with reference to the schematic flow charts and / or schematic block diagrams of the methods, devices, systems, and program products according to the embodiments. It should be understood that each box in the schematic flow chart and / or schematic block diagram and the combination of each box in the schematic flow chart and / or schematic block diagram 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 device to produce a machine, so that instructions executed by the processor of the computer or other programmable data processing device create means for implementing the functions specified in the schematic flow chart and / or schematic block diagram for one or more boxes.

[0034] The code may also be stored in a storage device, which is capable of directing a computer, other programmable data processing apparatus, or other device to function in a specific manner so that the instructions stored in the storage device produce a product including instructions for implementing the functions specified in one or more schematic flowcharts and / or schematic block diagrams.

[0035] The code may also be loaded onto a computer, other programmable data processing apparatus, or other device so that a series of operational steps are performed on the computer, other programmable apparatus, or other device to produce a computer-implemented process, so that the code running on the computer or other programmable apparatus provides a process for implementing the functions specified in one or more flowcharts and / or block diagram blocks.

[0036] The schematic flow charts and / or schematic block diagrams in the figures illustrate the architecture, functions and operations of possible implementations of the devices, systems, methods and program products according to various embodiments. In this regard, each box in the schematic flow charts and / or schematic block diagrams may represent a module, segment or portion of code, which includes one or more executable instructions of the code for implementing the specified logical function.

[0037] It should also be noted that in some alternative implementations, the functions indicated in the blocks may not appear in the order indicated in the figures. For example, two blocks shown in succession may be run substantially concurrently, or the blocks may sometimes be run in reverse order, depending on the functions involved. Other steps and methods are contemplated that are equivalent in function, logic, or effect to one or more blocks, or portions thereof, in the illustrated figures.

[0038] Although various arrow types and line types can be adopted in flow charts and / or block diagrams, they are understood to not limit the scope of the corresponding embodiments. In fact, some arrows or other connectors can be used to indicate only the logical flow of the depicted embodiment. For example, an arrow can indicate a waiting or monitoring period of unspecified duration between the enumeration steps of the depicted embodiment. It should also be noted that each frame in the block diagram and / or flow chart and the combination of each frame in the block diagram and / or flow chart can be realized by a combination of a dedicated hardware-based system or dedicated hardware and code that performs a specified function or behavior.

[0039] The description of an element in each figure may refer to elements in subsequent figures. The same reference numerals refer to the same elements in all figures, including alternative embodiments of the same elements.

[0040] The UE can be configured in two different modes for PUSCH multi-antenna precoding, called codebook-based (CB) transmission and non-codebook-based (nCB) transmission. When the UE is configured with codebook-based PUSCH transmission, one SRS resource set for the codebook can be configured for the UE in the BWP of the cell. When the UE is configured with non-codebook-based PUSCH transmission, one SRS resource set for the non-codebook can be configured for the UE in the BWP of the cell.

[0041] To enable codebook-based PUSCH transmission, the UE should be configured to send one or more SRS resources for the codebook for uplink channel measurement. Based on the measurements of the configured SRS resources sent by the UE, the gNB determines the appropriate rank and precoding matrix from a predefined codebook (which includes a set of precoding matrices with different ranks) and sends the information to the UE when scheduling PUSCH transmission.

[0042] For non-codebook based PUSCH transmissions, the UE is required to measure the CSI-RS to obtain uplink channel information based on channel reciprocity. In this case, the CSI-RS resources, which are DL reference signaling sent by the gNB for DL ​​channel measurement, are associated with the SRS resource set used for non-codebook. The UE selects an uplink precoder it deems appropriate and applies the selected precoder to the configured SRS resource set, where one SRS resource is sent on each layer defined by the precoder. Based on the received SRS resources, the gNB decides to modify the UE selected precoder for the scheduled PUSCH transmission.

[0043] When the UE is equipped with 8 antenna ports (e.g., PUSCH or SRS antenna ports), the base station unit (e.g., gNB) may send a DCI (e.g., DCI with format 0_1 ​​or DCI with format 0_2) to the UE scheduling PUSCH transmissions utilizing up to 8 layers (i.e., PUSCH layers). The 8 antenna ports (e.g., PUSCH or SRS antenna ports) may be numbered as PUSCH or SRS antenna ports 1000, 1001, 1002, 1003, 1004, 1005, 1006, and 1007.

[0044] When a PUSCH layer is transmitted from a UE, the precoding matrix is ​​used to perform UL precoding on modulated data in a codebook-based PUSCH transmission. The UE shall perform UL precoding according to Equation 1.

[0045] Formula 1:

[0046]

[0047] Among them, the vector block is the modulated data to be transmitted; W0 is the precoding matrix applied to the vector block; and the vector block is the precoded data to be sent by the UE. v0 indicates the number of PUSCH layers or the rank of PUSCH. P0 corresponds to PUSCH antenna port 1000 and P ρ-1 Corresponding to PUSCH antenna port 1000+ρ-1. In the present invention, ρ=8.

[0048] Coherent transmission is described as follows:

[0049] If the UE reports full coherence and 8 antenna ports (i.e., PUSCH antenna ports 1000, 1001, 1002, 1003, 1004, 1005, 1006, and 1007) capabilities, all 8 PUSCH antenna ports can be used for coherent transmission of the PUSCH layer. For example, the precoding vector for each layer can have 8 non-zero elements, for example, is an effective precoding vector for rank 1 PUSCH transmission using 8 fully coherent antenna ports. If the phase difference between any two antenna ports among the multiple antenna ports is fixed, then the multiple antenna ports are coherent. If the phase difference between any two antenna ports among the multiple antenna ports is not fixed, then the multiple antenna ports are incoherent.

[0050] If the UE reports a partially coherent or non-coherent capability with 8 antenna ports (i.e., PUSCH antenna ports 1000, 1001, 1002, 1003, 1004, 1005, 1006, and 1007), only the coherent antenna ports (where the coherent antenna ports are part of the 8 antenna ports) can be used for transmission of one PUSCH layer. In particular, all 8 antenna ports are grouped into Ng antenna groups. All antenna ports within each antenna group are coherent, whereas antenna ports from different antenna groups are non-coherent. Several antenna layouts with different numbers of antenna groups are illustrated in FIG. Figure 1 middle.

[0051] exist Figure 1 In , Ng represents the number of antenna groups. M represents the number of vertical antennas in the antenna group. N represents the number of horizontal antennas in the antenna group. P represents the number of polarizations of each antenna. Each polarization of the antenna corresponds to an antenna port.

[0052] Antenna layout 1-a and antenna layout 1-b correspond to fully coherent antenna arrays, that is, all 8 antenna ports within each of antenna layout 1-a and antenna layout 1-b belong to one antenna group (e.g., antenna group #0, represented as nNg=0) and are coherent antenna ports.

[0053] Antenna layout 2-a and antenna layout 2-b correspond to partially coherent antenna arrays with two antenna groups (Ng=2). For example, in each of antenna layout 2-a and antenna layout 2-b, antenna group #0 (the first antenna group, denoted as nNg=0) and antenna group #1 (the second antenna group, denoted as nNg=1) each include four coherent antenna ports.

[0054] Antenna layout 3-a and antenna layout 3-b correspond to partially coherent antenna arrays with four antenna groups (Ng=4). For example, in each of antenna layout 3-a and antenna layout 3-b, 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) each include two coherent antenna ports.

[0055] Before discussing the codebook design, the UE needs to report its antenna layout including the number of antenna groups 1≤Ng≤4 and optionally the number of antennas in each antenna group (M, N, P), where M indicates the number of horizontal antennas, N indicates the number of vertical antennas, 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.

[0056] For partially coherent UEs, ie, Ng=2 or Ng=4, the same precoding scheme should be applied to both antenna layouts 2-a and 2-b and antenna layouts 3-a and 3-b.

[0057] The UE can report the supported maxRank∈{1,2,3,4,5,6,7,8}, i.e., the maximum number of PUSCH layers used for PUSCH transmission.

[0058] The gNB sends a DCI to the UE to schedule one or more PUSCH transmissions. Depending on the reported maxRank, the rank of the scheduled PUSCH transmissions 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, which is equal to or less than maxRank. A precoding matrix (which can also be called a precoder) should be determined for the scheduled PUSCH transmissions.

[0059] By the way, the number of columns of the precoding matrix indicates the number of layers of PUSCH transmission to which the precoding matrix can be applied. Therefore, the precoding matrix (i.e., precoder) can be further described as a rank R precoding matrix (precoder), for example, 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 represented as an R-layer precoding matrix (precoder), for example, a layer precoder (or a 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 antenna ports or 4 antenna ports or 8 antenna ports, the precoding matrix (precoder) can have 2 or 4 or 8 rows (represented as 2Tx, 4Tx, 8Tx).

[0060] The first embodiment relates to a precoder for rank=1 (rank 1 precoder).

[0061] For rank=1, one PUSCH layer (ie, a single layer) is scheduled for transmission. The single layer is transmitted by antenna ports from one antenna group (for both Ng=2 and Ng=4).

[0062] The first sub-embodiment of the first embodiment involves Ng=2.

[0063] According to the first sub-embodiment of the first embodiment, the rank 1 precoder for UE with Ng=2 is constructed by the following steps:

[0064] Step 111: Select an antenna group for single-layer transmission (ie, one of the first antenna group (nNg=0) and the second antenna group (nNg=1)).

[0065] Step 112: Select 4Tx single-layer precoder W from 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 4Tx,1 , and the precoding vector elements of the selected 4Tx single-layer precoder without the normalization factor are applied to the antenna ports corresponding to the selected antenna group (one of the first antenna group and the second antenna group). Other elements corresponding to the non-selected antenna group (the other of the first antenna group and the second antenna group) in the single layer are set to '0'.

[0066] Step 113: Set the normalization factor of the final 8Tx precoder to

[0067] Table 6.3.1.5-2: Precoding matrix W for single-layer transmission using four antenna ports with transform precoding enabled.

[0068]

[0069]

[0070] Table 6.3.1.5-3: Precoding matrix W for single-layer transmission using four antenna ports with transform precoding disabled.

[0071]

[0072] The first example of the first sub-embodiment of the first embodiment is described as follows: In step 111, the first antenna group (nNg=0) is selected. In step 112, a 4Tx single-layer precoder is selected. (ie, TPMI index = 13), and the precoding vector element of the selected 4Tx single-layer precoder without the normalization factor (ie, [1 1 jj] T ) is applied to antenna ports 0, 1, 4, 5 corresponding to the selected first antenna group. The other elements in the single layer corresponding to the non-selected second antenna group are set to '0'. In step 113, the normalization factor is set to Therefore, the 8Tx rank 1 precoder is constructed as

[0073] The second example of the first sub-embodiment of the first embodiment is described as follows: In step 111, a second antenna group (nNg=1) is selected. In step 112, a 4Tx single-layer precoder is selected. (ie, TPMI index = 24), and the precoding vector element of the selected 4Tx single-layer precoder without the normalization factor (ie, [1 - j 1 - j] T ) is applied to antenna ports 2, 3, 6, 7 corresponding to the selected second antenna group. The other elements in the single layer corresponding to the non-selected first antenna group are set to '0'. In step 113, the normalization factor is set to Therefore, the 8Tx rank 1 precoder is constructed as

[0074] A second sub-embodiment of the first embodiment involves Ng=4.

[0075] According to the second sub-embodiment of the first embodiment, a rank 1 precoder for a UE with Ng=4 is constructed by the following steps:

[0076] Step 121: Select an antenna group for single-layer transmission (ie, one of the first antenna group (nNg=0), the second antenna group (nNg=1), the third antenna group (nNg=2), and the fourth antenna group (nNg=3)).

[0077] Step 122: From Include A 2Tx single-layer precoder is selected from the candidate 2Tx single-layer precoders, and the precoding vector elements of the selected 2Tx single-layer precoder without the normalization factor are applied to the antenna ports corresponding to the selected antenna group. Other elements corresponding to the non-selected antenna groups in the single layer are set to '0'.

[0078] Step 123: Set the normalization factor to

[0079] The first example of the second sub-embodiment of the first embodiment is described as follows: In step 121, the first antenna group (nNg=0) is selected. In step 122, a 2Tx single-layer precoder is selected. And the precoding vector element of the selected 2Tx single-layer precoder without normalization factor (i.e., [1 0] T ) is applied to antenna ports 0, 4 corresponding to the selected first antenna group. The other elements corresponding to the non-selected antenna groups (the second antenna group, the third antenna group, and the fourth antenna group) in the single layer are set to '0'. In step 123, the normalization factor is set to Therefore, the 8Tx rank 1 precoder is constructed as Similarly, if in step 122, 2Tx rank 1 precoder is selected One of the , then the 8Tx rank 1 precoder is constructed as one of them.

[0080] In the second example of the second sub-embodiment of the first embodiment, one of the second antenna group, the third antenna group, and the fourth antenna group is selected. Therefore, the available 8Tx rank 1 precoders for the second antenna group include Available 8Tx rank 1 precoders for the third antenna group include

[0081] And the available 8Tx rank 1 precoders for the fourth antenna group include

[0082] The second embodiment relates to a precoder for rank=2 (rank 2 precoder).

[0083] For rank=2, two PUSCH layers (ie, first layer and second layer) are scheduled for transmission.The first layer and the second layer are transmitted by antenna ports from two antenna groups (for both Ng=2 and Ng=4).

[0084] The first sub-embodiment of the second embodiment involves Ng=2.

[0085] The first layer and the second layer should be transmitted by the first antenna group (nNg=0) and the second antenna group (nNg=1), respectively.

[0086] The rank 2 precoder according to the first sub-embodiment of the second embodiment is constructed by the following steps:

[0087] Step 211: A 4Tx two-layer precoder is selected from Table 6.3.1.5-5 specified in 3GPP TS38.211 V16.0.0, a first precoding vector (i.e., first column) of the selected 4Tx rank 2 precoder without a normalization factor is applied to the antenna port corresponding to the first antenna group, and a second precoding vector (i.e., second column) of the selected 4Tx rank 2 precoder without a normalization factor is applied to the antenna port corresponding to the second antenna group. Other elements corresponding to non-selected antenna groups in each layer (each of the first layer and the second layer) are set to '0'.

[0088] Step 212: Set the normalization factor to

[0089] Table 6.3.1.5-5: Precoding matrix W for two-layer transmission using four antenna ports with transform precoding disabled.

[0090]

[0091] An example of the first sub-embodiment of the second embodiment is described as follows: In step 211, a 4Tx two-layer precoder is selected. (i.e., TPMI index = 16), the first precoding vector of the selected 4Tx two-layer precoder without normalization factor (i.e., [1j 1j] T ) is applied to antenna ports 0, 1, 4, 5 corresponding to the first antenna group, and the second precoding vector of the selected 4Tx two-layer precoder without a normalization factor (i.e., [1j-1-j] T ) is applied to antenna ports 2, 3, 6, 7 corresponding to the second antenna group. The other elements corresponding to the non-selected antenna groups in each of the first layer and the second layer are set to '0'. In step 212, the normalization factor is set to Therefore, the 8Tx rank 2 precoder is constructed as

[0092] A second sub-embodiment of the second embodiment involves Ng=4.

[0093] According to the second sub-embodiment of the second embodiment, the 8Tx rank 2 precoder for UE with Ng=4 is constructed by the following steps:

[0094] Step 221: Select 2 antenna groups from 4 antenna groups for two-layer transmission (i.e., the first antenna group (nNg=0), the second antenna group (nNg=1), the third antenna group (nNg=2), and the fourth antenna group (nNg=3)) from the candidate 2 antenna groups including {nNg=0, nNg=1}, {nNg=0, nNg=2}, {nNg=0, nNg=3}, {nNg=1, nNg=2}, {nNg=1, nNg=3}, and {nNg=2, nNg=3}. For example, if {nNg=0, nNg=1} is selected, nNg=0 is the first selected antenna group, and nNg=1 is the second selected antenna group.

[0095] Step 222: From Include Select 2Tx two-layer precoder W from the candidate 2Tx two-layer precoder 2Tx,2 , and the first precoding vector element (i.e., the first column) of the selected 2Tx two-layer precoder without the normalization factor is applied to the antenna port corresponding to the first selected antenna group, and the second precoding vector element (i.e., the second column) of the selected 2Tx two-layer precoder without the normalization factor is applied to the antenna port corresponding to the second selected antenna group. The other elements corresponding to the non-selected antenna groups in each layer (each of the first layer and the second layer) are set to '0'.

[0096] Step 223: Set the normalization factor to

[0097] An example of the second sub-embodiment of the second embodiment is described as follows: In step 221, two antenna groups {nNg=0, nNg=1} or {nNg=0, nNg=2} or {nNg=0, nNg=3} or {nNg=1, nNg=2} or {nNg=1, nNg=3} or {nNg=2, nNg=3} are selected. In step 222, two antenna groups {nNg=0, nNg=1} or {nNg=0, nNg=2} or {nNg=1, nNg=3} or {nNg=2, nNg=3} are selected. And the first precoding vector element of the selected 2Tx two-layer precoder without normalization factor (i.e., [1j] T ) is applied to the antenna port corresponding to the first selected antenna group, and the second precoding vector element (i.e., [1-j]) of the selected 2Tx two-layer precoder without the normalization factor is T) is applied to the antenna port corresponding to the second selected antenna group. The other elements corresponding to the non-selected antenna group in each of the first layer and the second layer are set to '0'. Therefore, for each of the two antenna groups including {nNg=0,nNg=1}, {nNg=0,nNg=2}, {nNg=0,nNg=3}, {nNg=1,nNg=2}, {nNg=1,nNg=3} and {nNg=2,nNg=3}, the 8Tx rank 2 precoder is constructed as and one of them.

[0098] The third embodiment relates to a precoder for rank=3 (rank 3 precoder).

[0099] For rank=3, three PUSCH layers (ie, first layer, second layer, and third layer) are scheduled for transmission. The first layer and the second layer are transmitted by antenna ports from two antenna groups (for Ng=2) or from three antenna groups (for Ng=4).

[0100] The first sub-embodiment of the third embodiment involves Ng=2.

[0101] The first layer should be transmitted by the first antenna group (nNg=0), and the second and third layers should be transmitted by the second antenna group (nNg=1).

[0102] According to the first sub-embodiment of the third embodiment, a rank 3 precoder for a UE with Ng=2 is constructed by the following steps:

[0103] Step 311: A 4Tx three-layer precoder is selected from Table 6.3.1.5-6 specified in 3GPP TS38.211 V16.0.0, and the first precoding vector (i.e., the first column) of the selected 4Tx three-layer precoder without a normalization factor is applied to the antenna port corresponding to the first antenna group for the first layer, and the last two (i.e., the second and third) precoding vectors (i.e., the second and third columns) of the selected 4Tx three-layer precoder without a normalization factor are applied to the antenna port corresponding to the second antenna group for the second and third layers. Other elements corresponding to non-selected antenna groups in each layer (each of the first, second, and third layers) are set to '0'.

[0104] Step 312: Set the normalization factor to

[0105] Table 6.3.1.5-6: Precoding matrix W for three-layer transmission using four antenna ports with transform precoding disabled.

[0106]

[0107] An example of a first sub-embodiment of the third embodiment is described as follows: In step 311, a 4Tx rank 3 precoder is selected. (i.e., TPMI index = 3), and the first precoding vector (i.e., first column) of the selected 4Tx rank 3 precoder without normalization factor (i.e., [1 1 1 1] T ) is applied to antenna ports 0, 1, 4, 5 corresponding to the first antenna group for the first layer, and the second precoding vector and the third precoding vector (i.e., the second column and the third column) of the selected 4Tx three-layer precoder without a normalization factor (i.e., [1 -1 1 -1] T and [1 1 -1-1] T ) is applied to antenna ports 2, 3, 6, 7 corresponding to the second antenna group for the second and third layers. The other elements corresponding to the non-selected antenna groups in each of the first, second and third layers are set to '0'. In step 312, the normalization factor is set to Therefore, the 8Tx rank 3 precoder is constructed as

[0108] The second sub-embodiment of the third embodiment involves Ng=4.

[0109] According to the second sub-embodiment of the third embodiment, the 8Tx rank 3 precoder for UE with Ng=4 is constructed by the following steps:

[0110] Step 321: Select three antenna groups from four antenna groups for three-layer transmission (i.e., the first antenna group (nNg=0), the second antenna group (nNg=1), the third antenna group (nNg=2), and the fourth antenna group (nNg=3)) from the candidate three antenna groups including {nNg=0, nNg=1, nNg=2}, {nNg=0, nNg=1, nNg=3}, {nNg=0, nNg=2, nNg=3}, and {nNg=1, nNg=2, nNg=3}. For example, if {nNg=0, nNg=1, nNg=3} is selected, then nNg=0 is the first selected antenna group, nNg=1 is the second selected antenna group, and nNg=3 is the third selected antenna group.

[0111] Step 322: From including and Select the 2Tx three-layer precoder matrix W from the candidate 2Tx three-layer precoder 2Tx,3, and a first precoding vector element (i.e., a first column) of the selected 2Tx three-layer precoder without a normalization factor is applied to the antenna port corresponding to the first selected antenna group, and a second precoding vector element (i.e., a second column) of the selected 2Tx three-layer precoder without a normalization factor is applied to the antenna port corresponding to the second selected antenna group, and a third precoding vector element (i.e., a third column) of the selected 2Tx three-layer precoder without a normalization factor is applied to the antenna port corresponding to the third selected antenna group. Other elements corresponding to non-selected antenna groups in each layer (each of the first layer, the second layer, and the third layer) are set to '0'.

[0112] Step 323: Set the normalization factor to

[0113] The first example of the second sub-embodiment of the third embodiment is described as follows: In step 321, three antenna groups {nNg=0, nNg=1, nNg=3} are selected. In step 322, a 2Tx three-layer precoder matrix is ​​selected. And the first precoding vector element (i.e., the first column) of the selected 2Tx three-layer precoder without the normalization factor (i.e.,

[10] T ) is applied to antenna ports 0, 4 corresponding to the first selected antenna group nNg=0, and the second precoding vector element (i.e., the second column) of the selected 2Tx three-layer precoder without a normalization factor (i.e., [0 1] T ) is applied to antenna ports 1, 5 corresponding to the second selected antenna group nNg=1, and the third precoding vector element (i.e., the third column) of the selected 2Tx three-layer precoder without a normalization factor (i.e., [1 0] T ) is applied to antenna ports 3, 7 corresponding to the third selected antenna group nNg=3. The other elements corresponding to the non-selected antenna groups in each of the first layer, the second layer and the third layer are set to '0'. In step 323, the normalization factor is set to Therefore, the 8Tx rank 3 precoder is constructed as

[0114] The second example of the second sub-embodiment of the third embodiment is described as follows: In step 321, three antenna groups {nNg=1, nNg=2, nNg=3} are selected. In step 322, a 2Tx three-layer precoder matrix is ​​selected. And the first precoding vector element (i.e., the first column) of the selected 2Tx three-layer precoder without the normalization factor (i.e., [1 1] T) is applied to antenna ports 1, 5 corresponding to the first selected antenna group nNg=1, and the second precoding vector element (i.e., the second column) of the selected 2Tx three-layer precoder without a normalization factor (i.e., [1 -1] T ) is applied to antenna ports 2, 6 corresponding to the second selected antenna group nNg=2, and the third precoding vector element (i.e., the third column) of the selected 2Tx three-layer precoder without the normalization factor (i.e., [1-j] T ) is applied to antenna ports 3, 7 corresponding to the third selected antenna group nNg=3. The other elements corresponding to the non-selected antenna groups in each of the first layer, the second layer and the third layer are set to '0'. In step 323, the normalization factor is set to Therefore, the 8Tx rank 3 precoder is constructed as

[0115] The fourth embodiment relates to a precoder for rank=4 (rank-4 precoder).

[0116] For rank=4, four PUSCH layers (i.e., first, second, third, and fourth layers) are scheduled for transmission. The 4 PUSCH layers should be sent by antenna ports from 2 antenna groups (for Ng=2) or from 4 antenna groups (for Ng=4).

[0117] The first sub-embodiment of the fourth embodiment relates to Ng=2.

[0118] The first and second layers should be transmitted by the first antenna group (nNg=0), and the third and fourth layers should be transmitted by the second antenna group (nNg=1).

[0119] According to the first sub-embodiment of the fourth embodiment, a rank 4 precoder for a UE with Ng=2 is constructed by the following steps:

[0120] Step 411: A 4Tx four-layer precoder is selected from Table 6.3.1.5-7 specified in 3GPP TS38.211 V16.0.0, and the first two (i.e., first and second) precoding vectors (i.e., first and second columns) of the selected 4Tx four-layer precoder without a normalization factor are applied to antenna ports 0, 1, 4, 5 corresponding to the first antenna group, and the last two (i.e., third and fourth) precoding vectors (i.e., third and fourth columns) of the selected 4Tx four-layer precoder without a normalization factor are applied to antenna ports 2, 3, 6, 7 corresponding to the second antenna group. Other elements corresponding to non-selected antenna groups in each layer (i.e., each of the first layer, the second layer, the third layer, and the fourth layer) are set to '0'.

[0121] Step 412: Set the normalization factor to 1 / 4.

[0122] Table 6.3.1.5-7: Precoding matrix W for four-layer transmission using four antenna ports with transform precoding disabled.

[0123]

[0124] A first example of the first sub-embodiment of the fourth embodiment is described as follows: In step 411, select (i.e., TPMI index = 0), the first two (i.e., first and second) precoding vectors (i.e., first and second columns) of the selected 4Tx four-layer precoder without normalization factor (i.e., [1 0 0 0] T and [0 1 0 0] T ) is applied to antenna ports 0, 1, 4, 5 corresponding to the first antenna group for the first layer and the second layer, and the last two (i.e., the third and fourth) precoding vectors (i.e., the third and fourth columns) of the selected 4Tx four-layer precoder without a normalization factor (i.e.: [0 0 1 0] T and [0 0 0 1] T ) is applied to antenna ports 2, 3, 6, 7 corresponding to the second antenna group for the third and fourth layers. The other elements corresponding to the non-selected antenna groups in each of the first, second, third, and fourth layers are set to '0'. In step 412, the normalization factor is set to 1 / 4. Therefore, the 8Tx rank 4 precoder is constructed as

[0125] The second example of the first sub-embodiment of the fourth embodiment is described as follows: In step 411, select (ie, TPMI index = 2), the first two (ie, first and second) precoding vectors (ie, first and second columns) of the selected 4Tx four-layer precoder without normalization factor (ie: [1 0j 0] T and [1 0-j 0] T ) is applied to antenna ports 0, 1, 4, 5 corresponding to the first antenna group for the first layer and the second layer, and the last two (i.e., the third and fourth) precoding vectors (i.e., the third and fourth columns) of the selected 4Tx four-layer precoder without a normalization factor (i.e.: [0 1 0j] T and [0 1 0-j] T ) is applied to antenna ports 2, 3, 6, 7 corresponding to the second antenna group for the third and fourth layers. The other elements corresponding to the non-selected antenna groups in each of the first, second, third, and fourth layers are set to '0'. In step 412, the normalization factor is set to 1 / 4. Therefore, the 8Tx rank 4 precoder is constructed as

[0126] The second sub-embodiment of the fourth embodiment relates to Ng=4.

[0127] The first layer should be transmitted by the first antenna group (nNg=0), the second layer should be transmitted by the second antenna group (nNg=1), the third layer should be transmitted by the third antenna group (nNg=2), and the fourth layer should be transmitted by the fourth antenna group (nNg=3).

[0128] According to the second sub-embodiment of the fourth embodiment, a rank 4 precoder for a UE with Ng=4 is constructed by the following steps:

[0129] Step 421: Select candidate 2Tx four-layer precoder and Select the 2Tx four-layer precoder matrix W 2Tx,4 , and a first precoding vector (i.e., a first column) of the selected 2Tx four-layer precoder without a normalization factor is applied to antenna ports 0, 4 corresponding to the first antenna group, a second precoding vector (i.e., a second column) of the selected 2Tx four-layer precoder without a normalization factor is applied to antenna ports 1, 5 corresponding to the second antenna group, a third precoding vector (i.e., a third column) of the selected 2Tx four-layer precoder without a normalization factor is applied to antenna ports 2, 6 corresponding to the third antenna group, and a fourth precoding vector (i.e., a fourth column) of the selected 2Tx four-layer precoder without a normalization factor is applied to antenna ports 3, 7 corresponding to the fourth antenna group. Other elements corresponding to non-selected antenna groups in each layer (i.e., each of the first layer, the second layer, the third layer, and the fourth layer) are set to '0'.

[0130] Step 422: Set the normalization factor to

[0131] An example of the second sub-embodiment of the fourth embodiment is described as follows: In step 421, select and One of the above, the first precoding vector (i.e., the first column) of the selected 2Tx four-layer precoder without the normalization factor (e.g., for For

[10] T ) is applied to antenna ports 0 and 4 corresponding to the first antenna group for the first layer, and the second precoding vector (i.e., the second column) of the selected 2Tx four-layer precoder without the normalization factor (e.g., for is [0 1] T ) is applied to antenna ports 1 and 5 corresponding to the second antenna group for the second layer, and the third precoding vector (i.e., the third column) of the selected 2Tx four-layer precoder without the normalization factor (e.g., for is [1 0] T ) is applied to antenna ports 2, 6 corresponding to the third antenna group for the third layer, and the fourth precoding vector (i.e., the fourth column) of the selected 2Tx four-layer precoder without a normalization factor (e.g., for is [0 1] T ) is applied to antenna ports 3, 7 corresponding to the fourth antenna group for the fourth layer. The other elements corresponding to the non-selected antenna groups in each of the first layer, the second layer, the third layer, and the fourth layer are set to '0'. In step 422, the normalization factor is set to Therefore, the 8Tx rank 4 precoder is constructed as (against ), (against ), (against )and (against ).

[0132] The fifth embodiment relates to a precoder (rank 5 precoder, rank 6 precoder, rank 7 precoder, rank 8 precoder) for rank>4 (ie, rank=5, 6, 7, or 8).

[0133] For rank>4 layer PUSCH transmission, it is assumed that two codewords (CWs), i.e., the first CW (CW0) and the second CW (CW1), should be scheduled with the following CW-to-layer mapping rule (which is the same as the CW-to-layer mapping scheme for DL ​​with more than 4 layers):

[0134] Rank 5: CW0 is mapped to the first 2 layers (i.e., the first and second layers) and CW1 is mapped to the last 3 layers (i.e., the third, fourth, and fifth layers);

[0135] Rank 6: CW0 maps to the first 3 layers (i.e., the first, second, and third layers) and CW1 maps to the last 3 layers (i.e., the fourth, fifth, and sixth layers);

[0136] Rank 7: CW0 maps to the first 3 layers (i.e., the first, second, and third layers) and CW1 maps to the last 4 layers (i.e., the fourth, fifth, sixth, and seventh layers); and

[0137] Rank 8: CW0 is mapped to the first 4 layers (ie, the first, second, third, and fourth layers) and CW1 is mapped to the last 4 layers (ie, the fifth, sixth, seventh, and eighth layers).

[0138] The first sub-embodiment of the fifth embodiment relates to Ng=2.

[0139] Each CW (each of CW0 and CW1) is transmitted by one antenna group for each of rank 5, rank 6, rank 7, and rank 8. In particular, the layer mapped to CW0 is transmitted by the first antenna group (nNg=0), while the layer mapped to CW1 is transmitted by the second antenna group (nNg=1).

[0140] In order to simplify the specification workload, an antenna group specific TPMI indication mechanism is proposed to construct a precoder for a rank greater than 4 (i.e., more than 4 layers). The TPMI consists of two parts (i.e., a first part and a second part), where the first part indicates a 4Tx precoder for a first antenna group and the second part indicates a 4Tx precoder for a second antenna group.

[0141] For rank=5, the 4Tx two-layer precoder from Table 6.3.1.5-5 specified in 3GPP TS38.211 V16.0.0 and the 4Tx three-layer precoder from Table 6.3.1.5-6 specified in 3GPP TS38.211 V16.0.0 are selected. The 4Tx two-layer precoder is applied to antenna ports 0, 1, 4, 5 corresponding to the first antenna group for the first and second layers. The 4Tx three-layer precoder is applied to antenna ports 2, 3, 6, 7 corresponding to the second antenna group for the third, fourth and fifth layers. The final rank 5 precoding matrix should be normalized so that the power of the precoder is not greater than 1.

[0142] For rank=6, a first 4Tx three-layer precoder from Table 6.3.1.5-6 specified in 3GPP TS38.211 V16.0.0 and a second 4Tx three-layer precoder from Table 6.3.1.5-6 specified in 3GPP TS38.211 V16.0.0 are selected. The first 4Tx three-layer precoder is applied to antenna ports 0, 1, 4, 5 corresponding to the first antenna group for the first, second and third layers. The second 4Tx three-layer precoder is applied to antenna ports 2, 3, 6, 7 corresponding to the second antenna group for the fourth, fifth and sixth layers. The final rank 6 precoding matrix should be normalized so that the power of the precoder is not greater than 1.

[0143] For rank = 7, the 4Tx three-layer precoder from Table 6.3.1.5-6 specified in 3GPP TS38.211 V16.0.0 and the 4Tx four-layer precoder from Table 6.3.1.5-7 specified in 3GPP TS38.211 V16.0.0 are selected. The 4Tx three-layer precoder is applied to antenna ports 0, 1, 4, 5 corresponding to the first antenna group for the first, second and third layers. The 4Tx four-layer precoder is applied to antenna ports 2, 3, 6, 7 corresponding to the second antenna group for the fourth, fifth, sixth and seventh layers. The final rank 7 precoding matrix should be normalized so that the power of the precoder is not greater than 1.

[0144] For rank = 8, a first 4Tx four-layer precoder from Table 6.3.1.5-7 specified in 3GPP TS38.211 V16.0.0 and a second 4Tx four-layer precoder from Table 6.3.1.5-7 specified in 3GPP TS38.211 V16.0.0 are selected. The first 4Tx four-layer precoder is applied to antenna ports 0, 1, 4, 5 corresponding to the first antenna group for the first, second, third and fourth layers. The second 4Tx four-layer precoder is applied to antenna ports 2, 3, 6, 7 corresponding to the second antenna group for the fifth, sixth, seventh and eighth layers. The final rank 8 precoding matrix should be normalized so that the power of the precoder is not greater than 1.

[0145] An example of a first sub-embodiment of the fifth embodiment is described as follows: When the indication rank=5 and the selection and When 4Tx two-layer precoder Applied to antenna ports 0, 1, 4, 5 corresponding to the first antenna group for the first and second layers. 4Tx three-layer precoder Applied to antenna ports 2, 3, 6, 7 corresponding to the second antenna group for the third, fourth and fifth layers. Therefore, the 8Tx rank 5 precoder is constructed as

[0146] The second sub-embodiment of the fifth embodiment relates to Ng=4.

[0147] For each of rank 5, rank 6, rank 7, and rank 8, each CW (each of CW0 and CW1) is transmitted by two antenna groups. For example, the PUSCH layer mapped to CW0 is transmitted by the first antenna group and the second antenna group; and the PUSCH layer mapped to CW1 is transmitted by the third antenna group and the fourth antenna group.

[0148] The layer combination for Ng=4 (ie, the number of layers transmitted by each antenna group) is proposed as follows:

[0149] Rank 5 in case of two CWs: 1+1+2+1. That is, the first layer is transmitted by the first antenna group, the second layer is transmitted by the second antenna group, the third and fourth layers are transmitted by the third antenna group, and the fifth layer is transmitted by the fourth antenna group.

[0150] Rank 6 in case of two CWs: 2+1+2+1. That is, the first and second layers are transmitted by the first antenna group, the third layer is transmitted by the second antenna group, the fourth and fifth layers are transmitted by the third antenna group, and the sixth layer is transmitted by the fourth antenna group.

[0151] Rank 7 in the case of two CWs: 2+1+2+2. That is, the first and second layers are transmitted by the first antenna group, the third layer is transmitted by the second antenna group, the fourth and fifth layers are transmitted by the third antenna group, and the sixth and seventh layers are transmitted by the fourth antenna group.

[0152] Rank 8 in the case of two CWs: 2+2+2+2. That is, the first and second layers are transmitted by the first antenna group, the third and fourth layers are transmitted by the second antenna group, the fifth and sixth layers are transmitted by the third antenna group, and the seventh and eighth layers are transmitted by the fourth antenna group.

[0153] In order to simplify the specification workload, an antenna group specific TPMI indication mechanism is proposed to construct a precoder for a rank greater than 4 (i.e., more than 4 layers). The TPMI consists of two parts (i.e., a first part and a second part), where the first part indicates a 2Tx precoder for the first antenna group and the second antenna group, and the second part indicates a 2Tx precoder for the third antenna group and the fourth antenna group.

[0154] For rank=5, a 2Tx two-layer precoder selected from the candidate 2Tx two-layer precoders described in the second sub-embodiment of the second embodiment and a 2Tx three-layer precoder selected from the candidate 2Tx three-layer precoders described in the second sub-embodiment of the third embodiment are selected. The first precoding vector (i.e., the first column) of the selected 2Tx two-layer precoder is applied to antenna ports 0, 4 corresponding to the first antenna group for the first layer, the second precoding vector (i.e., the second column) of the selected 2Tx two-layer precoder is applied to antenna ports 1, 5 corresponding to the second antenna group for the second layer, the first precoding vector and the second precoding vector (i.e., the first column and the second column) of the selected 2Tx three-layer precoder are applied to antenna ports 2, 6 corresponding to the third antenna group for the third and fourth layers, and the third precoding vector (i.e., the third column) of the selected 2Tx three-layer precoder is applied to antenna ports 3, 7 corresponding to the fourth antenna group for the fifth layer. The final rank 5 precoding matrix should be normalized so that the power of the precoder is not greater than 1.

[0155] For rank=6, a first 2Tx three-layer precoder selected from the candidate 2Tx three-layer precoders described in the second sub-embodiment of the third embodiment and a second 2Tx three-layer precoder selected from the candidate precoders described in the second sub-embodiment of the third embodiment are selected. The first precoding vector and the second precoding vector (i.e., the first column and the second column) of the first selected 2Tx three-layer precoder are applied to antenna ports 0, 4 corresponding to the first antenna group for the first layer and the second layer, the third precoding vector (i.e., the third column) of the first selected 2Tx three-layer precoder is applied to antenna ports 1, 5 corresponding to the second antenna group for the third layer, the first precoding vector and the second precoding vector (i.e., the first column and the second column) of the second selected 2Tx three-layer precoder are applied to antenna ports 2, 6 corresponding to the third antenna group for the fourth layer and the fifth layer, and the third precoding vector (i.e., the third column) of the second selected 2Tx three-layer precoder is applied to antenna ports 3, 7 corresponding to the fourth antenna group for the sixth layer. The final rank 6 precoding matrix should be normalized so that the power of the precoder is not greater than 1.

[0156] For rank=7, a 2Tx three-layer precoder selected from the candidate 2Tx three-layer precoder described in the second sub-embodiment of the third embodiment and a 2Tx four-layer precoder selected from the candidate 2Tx four-layer precoder described in the second sub-embodiment of the fourth embodiment are selected. The first precoding vector and the second precoding vector (i.e., the first column and the second column) of the selected 2Tx three-layer precoder are applied to antenna ports 0, 4 corresponding to the first antenna group for the first and second layers, the third precoding vector (i.e., the third column) of the selected 2Tx three-layer precoder is applied to antenna ports 1, 5 corresponding to the second antenna group for the third layer, the first precoding vector and the second precoding vector (i.e., the first column and the second column) of the selected 2Tx four-layer precoder are applied to antenna ports 2, 6 corresponding to the third antenna group for the fourth and fifth layers, and the third precoding vector and the fourth precoding vector (i.e., the third column and the fourth column) of the selected 2Tx four-layer precoder are applied to antenna ports 3, 7 corresponding to the fourth antenna group for the sixth and seventh layers. The final rank-7 precoding matrix should be normalized so that the precoder power is no greater than 1.

[0157] For rank=8, a first 2Tx four-layer precoder selected from the candidate 2Tx four-layer precoders described in the second sub-embodiment of the fourth embodiment and a second 2Tx four-layer precoder selected from the candidate 2Tx four-layer precoders described in the second sub-embodiment of the fourth embodiment are selected. The first precoding vector and the second precoding vector (i.e., the first column and the second column) of the first selected 2Tx four-layer precoder are applied to antenna ports 0, 4 corresponding to the first antenna group for the first and second layers, the third precoding vector and the fourth precoding vector (i.e., the third column and the fourth column) of the first selected 2Tx four-layer precoder are applied to antenna ports 1, 5 corresponding to the second antenna group for the third and fourth layers, the first precoding vector and the second precoding vector (i.e., the first column and the second column) of the second selected 2Tx four-layer precoder are applied to antenna ports 2, 6 corresponding to the third antenna group for the fifth and sixth layers, and the third precoding vector and the fourth precoding vector (i.e., the third column and the fourth column) of the second selected 2Tx four-layer precoder are applied to antenna ports 3, 7 corresponding to the fourth antenna group for the seventh and eighth layers. The final rank-8 precoding matrix should be normalized so that the precoder power is no greater than 1.

[0158] An example of the second sub-embodiment of the fifth embodiment is described as follows: When the indication rank = 7 and the selection and When , the first precoding vector and the second precoding vector of the 2Tx three-layer precoding coder are selected ([1 1] T , [1 -1] T ) is applied to antenna ports 0 and 4 corresponding to the first antenna group for the first layer and the second layer, and the third precoding vector ([1j]) of the 2Tx three-layer precoder is selected. T ) is applied to antenna ports 1 and 5 corresponding to the second antenna group for the third layer, and the first precoding vector and the second precoding vector of the 2Tx four-layer precoder are selected ([1 1] T , [1 -1] T ) is applied to antenna ports 2 and 6 corresponding to the third antenna group for the fourth and fifth layers, and the third precoding vector and the fourth precoding vector of the 2Tx four-layer precoder are selected ([1j] T , [1-j] T ) is applied to antenna ports 3 and 7 corresponding to the fourth antenna group for the sixth and seventh layers. Therefore, the 8Tx rank 7 precoder is constructed as

[0159] The sixth embodiment relates to TPMI indication.

[0160] The precoding matrix, i.e., the precoder, should be indicated to the UE in the DCI that schedules the PUSCH transmission. In NR Release 17, the transmit rank index (TRI) and the transmit precoding matrix index (TPMI) are jointly indicated by the precoding information and layer number field (all 62 precoders for 4Tx UEs with maximum rank 4 transmission) of the scheduling DCI. For 8Tx UEs, the available precoding matrix is ​​much larger. In view of the above, the present disclosure proposes to include separate TRI fields and TPMI fields in the scheduling DCI. Considering that the transmission rank is exactly the same as the number of DMRS ports used for channel estimation for the scheduled PUSCH transmission. The transmission rank can be implicitly determined by the antenna port field, which is used to indicate the DMRS port used for the scheduled PUSCH transmission using the DMRS indication table. This means that the TRI field is unnecessary. The TPMI field only needs to indicate the precoding matrix corresponding to each rank.

[0161] Based on the codebook structures discussed in the first to fifth embodiments, the summary of TPMI indication is summarized as follows:

[0162] For partially coherent UEs with Ng=2, the 4Tx TPMI will have a bit width determined by the maximum number of precoders corresponding to each supported rank for dynamic rank indication.

[0163] The required number of bits of the TPMI field for each of rank 1, rank 2, rank 3, rank 4, rank 5, rank 6, rank 7 and rank 8 for partially coherent UEs with Ng=2 is summarized as follows:

[0164] For rank 1, 1 bit (antenna group selection indicator for indicating one of the first antenna group and the second antenna group) + 5 bits (4Tx single-layer TPMI indicator from Table 6.3.1.5-2 for DFT-s-OFDM waveform or from Table 6.3.1.5-3 for CP-OFDM waveform) = 6 bits.

[0165] For rank 2, 5 bits (4Tx two-layer TPMI indicator from Table 6.3.1.5-5).

[0166] For rank 3, 3 bits (4Tx three-layer TPMI indicator from Table 6.3.1.5-6).

[0167] For rank 4, 3 bits (4Tx four-layer TPMI indicator from Table 6.3.1.5-7).

[0168] For rank 5, 5 bits (4Tx two-layer TPMI indicator from Table 6.3.1.5-5) + 3 bits (4Tx three-layer TPMI indicator from Table 6.3.1.5-6) ​​= 8 bits.

[0169] For rank 6, 3 bits (4Tx three-layer TPMI indicator from Table 6.3.1.5-6) ​​+ 3 bits (4Tx three-layer TPMI indicator from Table 6.3.1.5-6) ​​= 6 bits.

[0170] For rank 7, 3 bits (4Tx three-layer TPMI indicator from Table 6.3.1.5-6) ​​+ 3 bits (4Tx four-layer TPMI indicator from Table 6.3.1.5-7) = 6 bits.

[0171] For rank 8, 3 bits (4Tx four-layer TPMI indicator from Table 6.3.1.5-7) + 3 bits (4Tx four-layer TPMI indicator from Table 6.3.1.5-7) = 6 bits.

[0172] Different values ​​of maxRank (ie, the maximum rank supported) correspond to different UE capabilities. For example, the value of maxRank can be reported by the UE as 1, 4 or 8. The TPMI field bit width should be determined separately for maxRank=4 and maxRank=8, respectively.

[0173] Based on the disclosed codebook structure, for a partially coherent UE with Ng=2 having a maximum rank <=4 (e.g., maxRank=1, 2, 3, or 4), the bit width of the TPMI field can be 6 bits, because the maximum required bit width (i.e., for rank=1) is 6 bits for rank<=4, whereas for a partially coherent UE with Ng=2 having a maximum rank>4 (e.g., maxRank=5, 6, 7, or 8), the bit width of the TPMI field can be 8 bits, because the maximum required bit width (i.e., for rank=5) is 8 bits for rank>4.

[0174] For partially coherent UEs with Ng=4, the 2Tx TPMI will have a bit width determined by the maximum number of precoders corresponding to each supported rank for dynamic rank indication.

[0175] The required number of bits of the TPMI field for each of rank 1, rank 2, rank 3, rank 4, rank 5, rank 6, rank 7 and rank 8 for partially coherent UEs with Ng=4 is summarized as follows:

[0176] For rank 1, 2 bits (antenna group selection indicator for indicating one of the first antenna group, the second antenna group, the third antenna group, and the fourth antenna group) + 3 bits (2Tx single layer TPMI indicator for indicating one of the 6 candidate 2Tx single layer precoders described in step 122) = 5 bits.

[0177] For rank 2, 3 bits (antenna group selection indicators for indicating the 6 candidate 2-antenna groups described in step 221) + 3 bits (2Tx two-layer TPMI indicator for indicating one of the 5 candidate 2Tx two-layer precoders described in step 222) = 6 bits.

[0178] For rank 3, 2 bits (antenna group selection indicator for indicating the 4 candidate 3-antenna groups described in step 321) + 3 bits (2Tx three-layer TPMI indicator for indicating one of the 7 candidate 2Tx three-layer precoders described in step 322) = 5 bits.

[0179] For rank 4, 2 bits (2Tx four-layer TPMI indicator for indicating one of the 4 candidate 2Tx four-layer precoders described in step 422).

[0180] For rank 5, 3 bits (2Tx two-layer TPMI indicator) + 3 bits (2Tx three-layer TPMI indicator) = 6 bits.

[0181] For rank 6, 3 bits (2Tx three-layer TPMI indicator) + 3 bits (2Tx three-layer TPMI indicator) = 6 bits.

[0182] For rank 7, 3 bits (2Tx three-layer TPMI indicator) + 2 bits (2Tx four-layer TPMI indicator) = 5 bits.

[0183] For rank 8, 2 bits (2Tx four-layer TPMI indicator) + 2 bits (2Tx four-layer TPMI indicator) = 4 bits.

[0184] Based on the disclosed codebook structure, for partially coherent UEs with Ng=4 and maximum rank=1, the bit width of the TPMI field can be 5 bits, however, for partially coherent UEs with Ng=4 and maximum rank>1 (e.g., maximum rank=2, 3, 4, 5, 6, 7, 8), the bit width of the TPMI field can be 6 bits, because the maximum required bit width (i.e., for rank=2 and rank=5 and rank=6) is 6 bits for rank>1.

[0185] Figure 5 is a schematic flow chart illustrating an embodiment of a method 500 according to the present application. In some embodiments, the method 500 is performed by a device such as a remote unit (e.g., UE). In some embodiments, the method 500 can be performed by a processor (e.g., a microcontroller, a microprocessor, a CPU, a GPU, an auxiliary processing unit, an FPGA, etc.) running a program code.

[0186] Method 500 is a method performed at a UE, comprising: 502 receiving a DCI for scheduling a PUSCH, wherein the DCI includes an antenna port field indicating a number of DMRS ports, the number of DMRS ports determines a rank of the scheduled PUSCH, and the DCI further includes a TPMI field indicating one or two precoding matrices; and 504 determining a precoding matrix for the scheduled PUSCH based on the rank and the one or two precoding matrices.

[0187] In a certain embodiment, the method further includes reporting the number of antenna groups (Ng).

[0188] In a certain embodiment, the method further includes determining a bit width of the TPMI field according to a maximum rank having a value of 1, 4, or 8.

[0189] In a certain embodiment, when a rank-1, rank-2, or rank-3 PUSCH is scheduled for a UE with Ng=4, the TPMI field indicates the antenna group by which each PUSCH layer is transmitted by an antenna port from the antenna group.

[0190] In a certain embodiment, when a rank-4, rank-5, rank-6, rank-7, or rank-8 PUSCH is scheduled for a UE with Ng=4, it is predetermined by which antenna port from which antenna group each PUSCH layer is transmitted. In particular, when a rank 4 PUSCH is scheduled for a UE with Ng=4, the first PUSCH layer is sent by the antenna port from the first antenna group, the second PUSCH layer is sent by the antenna port from the second antenna group, the third PUSCH layer is sent by the antenna port from the third antenna group, and the fourth PUSCH layer is sent by the antenna port from the fourth antenna group; when a rank 5 PUSCH is scheduled for a UE with Ng=4, the first PUSCH layer is sent by the antenna port from the first antenna group, the second PUSCH layer is sent by the antenna port from the second antenna group, the third PUSCH layer and the fourth PUSCH layer are sent by the antenna port from the third antenna group, and the fifth PUSCH layer is sent by the antenna port from the fourth antenna group; when a rank 6 PUSCH is scheduled for a UE with Ng=4, the first PUSCH layer and the second PUSCH layer are sent by the antenna port from the first antenna group, the third PUSCH layer is sent by the antenna port from the second antenna group, the fourth PUSCH layer and the fifth PUSCH layer are sent by the antenna port from the fourth antenna group. The PUSCH layer is transmitted by the antenna port from the third antenna group, and the sixth PUSCH layer is transmitted by the antenna port from the fourth antenna group; when the UE scheduling rank 7 PUSCH with Ng=4, the first PUSCH layer and the second PUSCH layer are transmitted by the antenna port from the first antenna group, the third PUSCH layer is transmitted by the antenna port from the second antenna group, the fourth PUSCH layer and the fifth PUSCH layer are transmitted by the antenna port from the third antenna group, and the sixth PUSCH layer and the seventh PUSCH layer are transmitted by the antenna port from the fourth antenna group; and when the UE scheduling rank 8 PUSCH with Ng=4, the first PUSCH layer and the second PUSCH layer are transmitted by the antenna port from the first antenna group, the third PUSCH layer and the fourth PUSCH layer are transmitted by the antenna port from the second antenna group, the fifth PUSCH layer and the sixth PUSCH layer are transmitted by the antenna port from the third antenna group, and the seventh PUSCH layer and the eighth PUSCH layer are transmitted by the antenna port from the fourth antenna group.

[0191] In a certain embodiment, when a rank-1 PUSCH is scheduled for a UE with Ng=2, the TPMI field indicates the antenna group by which a single PUSCH layer is transmitted by antenna ports from that antenna group.

[0192] In a certain embodiment, when a rank-2, rank-3, rank-4, rank-5, rank-6, rank-7, or rank-8 PUSCH is scheduled for a UE with Ng=2, it is predetermined by which antenna port from which antenna group each PUSCH layer is transmitted. In particular, when the UE with Ng=2 schedules a rank 2 PUSCH, the first PUSCH layer is sent by the antenna port from the first antenna group, and the second PUSCH layer is sent by the antenna port from the second antenna group; when the UE with Ng=2 schedules a rank 3 PUSCH, the first PUSCH layer is sent by the antenna port from the first antenna group, and the second PUSCH layer and the third PUSCH layer are sent by the antenna port from the second antenna group; when the UE with Ng=2 schedules a rank 4 PUSCH, the first PUSCH layer and the second PUSCH layer are sent by the antenna port from the first antenna group, and the third PUSCH layer and the fourth PUSCH layer are sent by the antenna port from the second antenna group; when the UE with Ng=2 schedules a rank 5 PUSCH, the first PUSCH layer and the second PUSCH layer are sent by the antenna port from the first antenna group, and the third PUSCH layer, the fourth PUSCH layer and the fifth PUSCH layer are sent by the antenna port from the second antenna group; when Ng=2 schedules a rank 5 PUSCH, the first PUSCH layer and the second PUSCH layer are sent by the antenna port from the first antenna group, and the third PUSCH layer, the fourth PUSCH layer and the fifth PUSCH layer are sent by the antenna port from the second antenna group; =2 for UE scheduling rank 6 PUSCH, the first PUSCH layer, the second PUSCH layer and the third PUSCH layer are sent by the antenna ports from the first antenna group, and the fourth PUSCH layer, the fifth PUSCH layer and the sixth PUSCH layer are sent by the antenna ports from the second antenna group; when the UE scheduling rank 7 PUSCH with Ng=2, the first PUSCH layer, the second PUSCH layer and the third PUSCH layer are sent by the antenna ports from the first antenna group, and the fourth PUSCH layer, the fifth PUSCH layer, the sixth PUSCH layer and the seventh PUSCH layer are sent by the antenna ports from the second antenna group; and when the UE scheduling rank 8 PUSCH with Ng=2, the first PUSCH layer, the second PUSCH layer, the third PUSCH layer and the fourth PUSCH layer are sent by the antenna ports from the first antenna group, and the fifth PUSCH layer, the sixth PUSCH layer, the seventh PUSCH layer and the eighth PUSCH layer are sent by the antenna ports from the second antenna group.

[0193] Figure 6 6 is a schematic flow chart illustrating an embodiment of a method 600 according to the present application. In some embodiments, the method 600 is performed by a device such as a base station unit. In some embodiments, the method 600 can be performed by a processor (e.g., a microcontroller, a microprocessor, a CPU, a GPU, an auxiliary processing unit, an FPGA, etc.) running program code.

[0194] Method 600 may include: 602 sending a DCI for scheduling a PUSCH, wherein the DCI includes an antenna port field indicating a number of DMRS ports, the number of DMRS ports determines a rank of the scheduled PUSCH, and the DCI further includes a TPMI field indicating one or two precoding matrices; and 604 determining a precoding matrix for the scheduled PUSCH based on the rank and one or two precoding matrices.

[0195] In a certain embodiment, the method further includes receiving a number of antenna groups (Ng).

[0196] In a certain embodiment, the method further includes determining a bit width of the TPMI field according to a maximum rank having a value of 1, 4, or 8.

[0197] In a certain embodiment, when a rank-1, rank-2, or rank-3 PUSCH is scheduled for a UE with Ng=4, the TPMI field indicates the antenna group by which each PUSCH layer is transmitted by an antenna port from the antenna group.

[0198] In a certain embodiment, when a rank-4, rank-5, rank-6, rank-7, or rank-8 PUSCH is scheduled for a UE with Ng=4, it is predetermined by which antenna port from which antenna group each PUSCH layer is transmitted. In particular, when a rank 4 PUSCH is scheduled for a UE with Ng=4, the first PUSCH layer is sent by the antenna port from the first antenna group, the second PUSCH layer is sent by the antenna port from the second antenna group, the third PUSCH layer is sent by the antenna port from the third antenna group, and the fourth PUSCH layer is sent by the antenna port from the fourth antenna group; when a rank 5 PUSCH is scheduled for a UE with Ng=4, the first PUSCH layer is sent by the antenna port from the first antenna group, the second PUSCH layer is sent by the antenna port from the second antenna group, the third PUSCH layer and the fourth PUSCH layer are sent by the antenna port from the third antenna group, and the fifth PUSCH layer is sent by the antenna port from the fourth antenna group; when a rank 6 PUSCH is scheduled for a UE with Ng=4, the first PUSCH layer and the second PUSCH layer are sent by the antenna port from the first antenna group, the third PUSCH layer is sent by the antenna port from the second antenna group, the fourth PUSCH layer and the fifth PUSCH layer are sent by the antenna port from the fourth antenna group. The PUSCH layer is transmitted by the antenna port from the third antenna group, and the sixth PUSCH layer is transmitted by the antenna port from the fourth antenna group; when the UE scheduling rank 7 PUSCH with Ng=4, the first PUSCH layer and the second PUSCH layer are transmitted by the antenna port from the first antenna group, the third PUSCH layer is transmitted by the antenna port from the second antenna group, the fourth PUSCH layer and the fifth PUSCH layer are transmitted by the antenna port from the third antenna group, and the sixth PUSCH layer and the seventh PUSCH layer are transmitted by the antenna port from the fourth antenna group; and when the UE scheduling rank 8 PUSCH with Ng=4, the first PUSCH layer and the second PUSCH layer are transmitted by the antenna port from the first antenna group, the third PUSCH layer and the fourth PUSCH layer are transmitted by the antenna port from the second antenna group, the fifth PUSCH layer and the sixth PUSCH layer are transmitted by the antenna port from the third antenna group, and the seventh PUSCH layer and the eighth PUSCH layer are transmitted by the antenna port from the fourth antenna group.

[0199] In a certain embodiment, when a rank-1 PUSCH is scheduled for a UE with Ng=2, the TPMI field indicates the antenna group by which a single PUSCH layer is transmitted by antenna ports from that antenna group.

[0200] In a certain embodiment, when a rank-2, rank-3, rank-4, rank-5, rank-6, rank-7, or rank-8 PUSCH is scheduled for a UE with Ng=2, it is predetermined by which antenna port from which antenna group each PUSCH layer is transmitted. In particular, when the UE with Ng=2 schedules a rank 2 PUSCH, the first PUSCH layer is sent by the antenna port from the first antenna group, and the second PUSCH layer is sent by the antenna port from the second antenna group; when the UE with Ng=2 schedules a rank 3 PUSCH, the first PUSCH layer is sent by the antenna port from the first antenna group, and the second PUSCH layer and the third PUSCH layer are sent by the antenna port from the second antenna group; when the UE with Ng=2 schedules a rank 4 PUSCH, the first PUSCH layer and the second PUSCH layer are sent by the antenna port from the first antenna group, and the third PUSCH layer and the fourth PUSCH layer are sent by the antenna port from the second antenna group; when the UE with Ng=2 schedules a rank 5 PUSCH, the first PUSCH layer and the second PUSCH layer are sent by the antenna port from the first antenna group, and the third PUSCH layer, the fourth PUSCH layer and the fifth PUSCH layer are sent by the antenna port from the second antenna group; when Ng=2 schedules a rank 5 PUSCH, the first PUSCH layer and the second PUSCH layer are sent by the antenna port from the first antenna group, and the third PUSCH layer, the fourth PUSCH layer and the fifth PUSCH layer are sent by the antenna port from the second antenna group; =2 for UE scheduling rank 6 PUSCH, the first PUSCH layer, the second PUSCH layer and the third PUSCH layer are sent by the antenna ports from the first antenna group, and the fourth PUSCH layer, the fifth PUSCH layer and the sixth PUSCH layer are sent by the antenna ports from the second antenna group; when the UE scheduling rank 7 PUSCH with Ng=2, the first PUSCH layer, the second PUSCH layer and the third PUSCH layer are sent by the antenna ports from the first antenna group, and the fourth PUSCH layer, the fifth PUSCH layer, the sixth PUSCH layer and the seventh PUSCH layer are sent by the antenna ports from the second antenna group; and when the UE scheduling rank 8 PUSCH with Ng=2, the first PUSCH layer, the second PUSCH layer, the third PUSCH layer and the fourth PUSCH layer are sent by the antenna ports from the first antenna group, and the fifth PUSCH layer, the sixth PUSCH layer, the seventh PUSCH layer and the eighth PUSCH layer are sent by the antenna ports from the second antenna group.

[0201] Figure 7 is a schematic block diagram illustrating an apparatus according to one embodiment.

[0202] refer to Figure 7 , UE (ie, remote unit) includes a processor, a memory and a transceiver. Processor implementation Figure 5 The functions, processes and / or methods proposed in.

[0203] The UE includes: a transceiver; and a processor coupled to the transceiver, wherein the processor is configured to receive, via the transceiver, a DCI for scheduling a PUSCH, wherein the DCI includes an antenna port field indicating a number of DMRS ports, the number of DMRS ports determining a rank of the scheduled PUSCH, and the DCI further includes a TPMI field indicating one or two precoding matrices; and determine a precoding matrix for the scheduled PUSCH according to the rank and the one or two precoding matrices.

[0204] In a certain embodiment, the processor is further configured to report the number of antenna groups (Ng) via the transceiver.

[0205] In some embodiment, the processor is further configured to determine the bit width of the TPMI field according to a maximum rank having a value of 1, 4, or 8.

[0206] In a certain embodiment, when a rank-1, rank-2, or rank-3 PUSCH is scheduled for a UE with Ng=4, the TPMI field indicates the antenna group by which each PUSCH layer is transmitted by an antenna port from the antenna group.

[0207] In a certain embodiment, when a rank-4, rank-5, rank-6, rank-7, or rank-8 PUSCH is scheduled for a UE with Ng=4, it is predetermined by which antenna port from which antenna group each PUSCH layer is transmitted. In particular, when a rank 4 PUSCH is scheduled for a UE with Ng=4, the first PUSCH layer is sent by the antenna port from the first antenna group, the second PUSCH layer is sent by the antenna port from the second antenna group, the third PUSCH layer is sent by the antenna port from the third antenna group, and the fourth PUSCH layer is sent by the antenna port from the fourth antenna group; when a rank 5 PUSCH is scheduled for a UE with Ng=4, the first PUSCH layer is sent by the antenna port from the first antenna group, the second PUSCH layer is sent by the antenna port from the second antenna group, the third PUSCH layer and the fourth PUSCH layer are sent by the antenna port from the third antenna group, and the fifth PUSCH layer is sent by the antenna port from the fourth antenna group; when a rank 6 PUSCH is scheduled for a UE with Ng=4, the first PUSCH layer and the second PUSCH layer are sent by the antenna port from the first antenna group, the third PUSCH layer is sent by the antenna port from the second antenna group, the fourth PUSCH layer and the fifth PUSCH layer are sent by the antenna port from the fourth antenna group. The PUSCH layer is transmitted by the antenna port from the third antenna group, and the sixth PUSCH layer is transmitted by the antenna port from the fourth antenna group; when the UE scheduling rank 7 PUSCH with Ng=4, the first PUSCH layer and the second PUSCH layer are transmitted by the antenna port from the first antenna group, the third PUSCH layer is transmitted by the antenna port from the second antenna group, the fourth PUSCH layer and the fifth PUSCH layer are transmitted by the antenna port from the third antenna group, and the sixth PUSCH layer and the seventh PUSCH layer are transmitted by the antenna port from the fourth antenna group; and when the UE scheduling rank 8 PUSCH with Ng=4, the first PUSCH layer and the second PUSCH layer are transmitted by the antenna port from the first antenna group, the third PUSCH layer and the fourth PUSCH layer are transmitted by the antenna port from the second antenna group, the fifth PUSCH layer and the sixth PUSCH layer are transmitted by the antenna port from the third antenna group, and the seventh PUSCH layer and the eighth PUSCH layer are transmitted by the antenna port from the fourth antenna group.

[0208] In a certain embodiment, when a rank-1 PUSCH is scheduled for a UE with Ng=2, the TPMI field indicates the antenna group by which a single PUSCH layer is transmitted by antenna ports from that antenna group.

[0209] In a certain embodiment, when a rank-2, rank-3, rank-4, rank-5, rank-6, rank-7, or rank-8 PUSCH is scheduled for a UE with Ng=2, it is predetermined by which antenna port from which antenna group each PUSCH layer is transmitted. In particular, when the UE with Ng=2 schedules a rank 2 PUSCH, the first PUSCH layer is sent by the antenna port from the first antenna group, and the second PUSCH layer is sent by the antenna port from the second antenna group; when the UE with Ng=2 schedules a rank 3 PUSCH, the first PUSCH layer is sent by the antenna port from the first antenna group, and the second PUSCH layer and the third PUSCH layer are sent by the antenna port from the second antenna group; when the UE with Ng=2 schedules a rank 4 PUSCH, the first PUSCH layer and the second PUSCH layer are sent by the antenna port from the first antenna group, and the third PUSCH layer and the fourth PUSCH layer are sent by the antenna port from the second antenna group; when the UE with Ng=2 schedules a rank 5 PUSCH, the first PUSCH layer and the second PUSCH layer are sent by the antenna port from the first antenna group, and the third PUSCH layer, the fourth PUSCH layer and the fifth PUSCH layer are sent by the antenna port from the second antenna group; when Ng=2 schedules a rank 5 PUSCH, the first PUSCH layer and the second PUSCH layer are sent by the antenna port from the first antenna group, and the third PUSCH layer, the fourth PUSCH layer and the fifth PUSCH layer are sent by the antenna port from the second antenna group; =2 for UE scheduling rank 6 PUSCH, the first PUSCH layer, the second PUSCH layer and the third PUSCH layer are sent by the antenna ports from the first antenna group, and the fourth PUSCH layer, the fifth PUSCH layer and the sixth PUSCH layer are sent by the antenna ports from the second antenna group; when the UE scheduling rank 7 PUSCH with Ng=2, the first PUSCH layer, the second PUSCH layer and the third PUSCH layer are sent by the antenna ports from the first antenna group, and the fourth PUSCH layer, the fifth PUSCH layer, the sixth PUSCH layer and the seventh PUSCH layer are sent by the antenna ports from the second antenna group; and when the UE scheduling rank 8 PUSCH with Ng=2, the first PUSCH layer, the second PUSCH layer, the third PUSCH layer and the fourth PUSCH layer are sent by the antenna ports from the first antenna group, and the fifth PUSCH layer, the sixth PUSCH layer, the seventh PUSCH layer and the eighth PUSCH layer are sent by the antenna ports from the second antenna group.

[0210] The gNB (i.e., base station unit) includes a processor, a memory, and a transceiver. Figure 6 The functions, processes and / or methods proposed in.

[0211] The base station unit includes: a transceiver; and a processor coupled to the transceiver, wherein the processor is configured to send a DCI for scheduling a PUSCH via the transceiver, wherein the DCI includes an antenna port field indicating a DMRS port number, the DMRS port number determines the rank of the scheduled PUSCH, and the DCI further includes a TPMI field indicating one or two precoding matrices; and determine a precoding matrix for the scheduled PUSCH according to the rank and the one or two precoding matrices.

[0212] In a certain embodiment, the processor is further configured to receive, via the transceiver, a number of antenna groups (Ng).

[0213] In some embodiment, the processor is further configured to determine the bit width of the TPMI field according to a maximum rank having a value of 1, 4, or 8.

[0214] In a certain embodiment, when a rank-1, rank-2, or rank-3 PUSCH is scheduled for a UE with Ng=4, the TPMI field indicates the antenna group by which each PUSCH layer is transmitted by an antenna port from the antenna group.

[0215] In a certain embodiment, when a rank-4, rank-5, rank-6, rank-7, or rank-8 PUSCH is scheduled for a UE with Ng=4, it is predetermined by which antenna port from which antenna group each PUSCH layer is transmitted. In particular, when a rank 4 PUSCH is scheduled for a UE with Ng=4, the first PUSCH layer is sent by the antenna port from the first antenna group, the second PUSCH layer is sent by the antenna port from the second antenna group, the third PUSCH layer is sent by the antenna port from the third antenna group, and the fourth PUSCH layer is sent by the antenna port from the fourth antenna group; when a rank 5 PUSCH is scheduled for a UE with Ng=4, the first PUSCH layer is sent by the antenna port from the first antenna group, the second PUSCH layer is sent by the antenna port from the second antenna group, the third PUSCH layer and the fourth PUSCH layer are sent by the antenna port from the third antenna group, and the fifth PUSCH layer is sent by the antenna port from the fourth antenna group; when a rank 6 PUSCH is scheduled for a UE with Ng=4, the first PUSCH layer and the second PUSCH layer are sent by the antenna port from the first antenna group, the third PUSCH layer is sent by the antenna port from the second antenna group, the fourth PUSCH layer and the fifth PUSCH layer are sent by the antenna port from the fourth antenna group. The PUSCH layer is transmitted by the antenna port from the third antenna group, and the sixth PUSCH layer is transmitted by the antenna port from the fourth antenna group; when the UE scheduling rank 7 PUSCH with Ng=4, the first PUSCH layer and the second PUSCH layer are transmitted by the antenna port from the first antenna group, the third PUSCH layer is transmitted by the antenna port from the second antenna group, the fourth PUSCH layer and the fifth PUSCH layer are transmitted by the antenna port from the third antenna group, and the sixth PUSCH layer and the seventh PUSCH layer are transmitted by the antenna port from the fourth antenna group; and when the UE scheduling rank 8 PUSCH with Ng=4, the first PUSCH layer and the second PUSCH layer are transmitted by the antenna port from the first antenna group, the third PUSCH layer and the fourth PUSCH layer are transmitted by the antenna port from the second antenna group, the fifth PUSCH layer and the sixth PUSCH layer are transmitted by the antenna port from the third antenna group, and the seventh PUSCH layer and the eighth PUSCH layer are transmitted by the antenna port from the fourth antenna group.

[0216] In a certain embodiment, when a rank-1 PUSCH is scheduled for a UE with Ng=2, the TPMI field indicates the antenna group by which a single PUSCH layer is transmitted by antenna ports from that antenna group.

[0217] In a certain embodiment, when a rank-2, rank-3, rank-4, rank-5, rank-6, rank-7, or rank-8 PUSCH is scheduled for a UE with Ng=2, it is predetermined by which antenna port from which antenna group each PUSCH layer is transmitted. In particular, when the UE with Ng=2 schedules a rank 2 PUSCH, the first PUSCH layer is sent by the antenna port from the first antenna group, and the second PUSCH layer is sent by the antenna port from the second antenna group; when the UE with Ng=2 schedules a rank 3 PUSCH, the first PUSCH layer is sent by the antenna port from the first antenna group, and the second PUSCH layer and the third PUSCH layer are sent by the antenna port from the second antenna group; when the UE with Ng=2 schedules a rank 4 PUSCH, the first PUSCH layer and the second PUSCH layer are sent by the antenna port from the first antenna group, and the third PUSCH layer and the fourth PUSCH layer are sent by the antenna port from the second antenna group; when the UE with Ng=2 schedules a rank 5 PUSCH, the first PUSCH layer and the second PUSCH layer are sent by the antenna port from the first antenna group, and the third PUSCH layer, the fourth PUSCH layer and the fifth PUSCH layer are sent by the antenna port from the second antenna group; when Ng=2 schedules a rank 5 PUSCH, the first PUSCH layer and the second PUSCH layer are sent by the antenna port from the first antenna group, and the third PUSCH layer, the fourth PUSCH layer and the fifth PUSCH layer are sent by the antenna port from the second antenna group; =2 for UE scheduling rank 6 PUSCH, the first PUSCH layer, the second PUSCH layer and the third PUSCH layer are sent by the antenna ports from the first antenna group, and the fourth PUSCH layer, the fifth PUSCH layer and the sixth PUSCH layer are sent by the antenna ports from the second antenna group; when the UE scheduling rank 7 PUSCH with Ng=2, the first PUSCH layer, the second PUSCH layer and the third PUSCH layer are sent by the antenna ports from the first antenna group, and the fourth PUSCH layer, the fifth PUSCH layer, the sixth PUSCH layer and the seventh PUSCH layer are sent by the antenna ports from the second antenna group; and when the UE scheduling rank 8 PUSCH with Ng=2, the first PUSCH layer, the second PUSCH layer, the third PUSCH layer and the fourth PUSCH layer are sent by the antenna ports from the first antenna group, and the fifth PUSCH layer, the sixth PUSCH layer, the seventh PUSCH layer and the eighth PUSCH layer are sent by the antenna ports from the second antenna group.

[0218] Each layer of the radio interface protocol can be implemented by a processor. The memory is connected to the processor to store various pieces of information for driving the processor. The transceiver is connected to the processor to send and / or receive radio signals. Needless to say, the transceiver can be implemented as a transmitter for sending radio signals and a receiver for receiving radio signals.

[0219] The memory may be located inside or outside the processor and connected to the processor through various well-known means.

[0220] In the above-described embodiments, the components and features of the embodiments are combined in a predetermined form. Unless otherwise explicitly stated, each component or feature should be considered as an option. Each component or feature can be implemented to be not associated with other components or features. In addition, the embodiment can be configured by associating some components and / or features. The order of the operations described in the embodiment can be changed. Some components or features of any embodiment can be included in another embodiment or replaced with components and features corresponding to another embodiment. It is clear that the claims that are not explicitly cited in the claims are combined to form an embodiment or are included in a new claim.

[0221] The embodiments may be implemented by hardware, firmware, software or a combination thereof. In the case of being implemented by hardware, according to the hardware implementation, the exemplary embodiments described herein may 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.

[0222] Embodiments may be practiced in other specific forms. The described embodiments will be considered in all respects to be illustrative only, and not restrictive. Therefore, the scope of the present invention is indicated in the appended claims rather than by the above description. All changes falling within the meaning and equivalent range of the claims will be included within the scope of the claims.

Claims

1. A user equipment (UE), comprising: Transceiver; as well as a processor coupled to the transceiver, wherein the processor is configured to receiving, via the transceiver, a DCI that schedules a PUSCH, wherein the DCI includes an antenna port field indicating a number of DMRS ports, the number of DMRS ports determining a rank of the scheduled PUSCH, and the DCI further includes a TPMI field indicating one or two precoding matrices; and The precoding matrix for the scheduled PUSCH is determined according to the rank and the one or two precoding matrices.

2. The UE according to claim 1, wherein: The processor is further configured to report a number of antenna groups (Ng) via the transceiver.

3. The UE according to claim 1, wherein: The processor is further configured to determine a bit width of the TPMI field according to a maximum rank having a value of 1, 4, or 8.

4. The UE according to claim 1, wherein: When a rank-1, rank-2, or rank-3 PUSCH is scheduled for a UE with Ng=4, the TPMI field indicates an antenna group, and each PUSCH layer is transmitted by an antenna port from the antenna group.

5. The UE according to claim 1, wherein: When a rank-4, rank-5, rank-6, rank-7, or rank-8 PUSCH is scheduled for a UE with Ng=4, it is predetermined by which antenna port from which antenna group each PUSCH layer is transmitted.

6. The UE according to claim 5, wherein: When a rank 4 PUSCH is scheduled for a UE with Ng=4, the first PUSCH layer is sent by antenna ports from the first antenna group, the second PUSCH layer is sent by antenna ports from the second antenna group, the third PUSCH layer is sent by antenna ports from the third antenna group, and the fourth PUSCH layer is sent by antenna ports from the fourth antenna group; When a rank 5 PUSCH is scheduled for a UE with Ng=4, the first PUSCH layer is sent by the antenna port from the first antenna group, the second PUSCH layer is sent by the antenna port from the second antenna group, the third PUSCH layer and the fourth PUSCH layer are sent by the antenna port from the third antenna group, and the fifth PUSCH layer is sent by the antenna port from the fourth antenna group; When a rank 6 PUSCH is scheduled for a UE with Ng=4, the first PUSCH layer and the second PUSCH layer are transmitted by antenna ports from the first antenna group, the third PUSCH layer is transmitted by antenna ports from the second antenna group, the fourth PUSCH layer and the fifth PUSCH layer are transmitted by antenna ports from the third antenna group, and the sixth PUSCH layer is transmitted by antenna ports from the fourth antenna group; When a rank 7 PUSCH is scheduled for a UE with Ng=4, the first PUSCH layer and the second PUSCH layer are transmitted by antenna ports from the first antenna group, the third PUSCH layer is transmitted by antenna ports from the second antenna group, the fourth PUSCH layer and the fifth PUSCH layer are transmitted by antenna ports from the third antenna group, and the sixth PUSCH layer and the seventh PUSCH layer are transmitted by antenna ports from the fourth antenna group; as well as When a rank 8 PUSCH is scheduled for a UE with Ng=4, the first PUSCH layer and the second PUSCH layer are sent by the antenna ports from the first antenna group, the third PUSCH layer and the fourth PUSCH layer are sent by the antenna ports from the second antenna group, the fifth PUSCH layer and the sixth PUSCH layer are sent by the antenna ports from the third antenna group, and the seventh PUSCH layer and the eighth PUSCH layer are sent by the antenna ports from the fourth antenna group.

7. The UE according to claim 1, wherein: When a rank-1 PUSCH is scheduled for a UE with Ng=2, the TPMI field indicates an antenna group by which a single PUSCH layer is transmitted by antenna ports from the antenna group.

8. The UE according to claim 1, wherein: When a rank-2, rank-3, rank-4, rank-5, rank-6, rank-7, or rank-8 PUSCH is scheduled for a UE with Ng=2, it is predetermined by which antenna port from which antenna group each PUSCH layer is transmitted.

9. The UE according to claim 8, wherein: When a rank-2 PUSCH is scheduled for a UE with Ng=2, the first PUSCH layer is transmitted by antenna ports from the first antenna group, and the second PUSCH layer is transmitted by antenna ports from the second antenna group; When a rank 3 PUSCH is scheduled for a UE with Ng=2, a first PUSCH layer is transmitted by antenna ports from the first antenna group, and a second PUSCH layer and a third PUSCH layer are transmitted by antenna ports from the second antenna group; When a rank 4 PUSCH is scheduled for a UE with Ng=2, a first PUSCH layer and a second PUSCH layer are transmitted by antenna ports from the first antenna group, and a third PUSCH layer and a fourth PUSCH layer are transmitted by antenna ports from the second antenna group; When a rank 5 PUSCH is scheduled for a UE with Ng=2, the first PUSCH layer and the second PUSCH layer are transmitted by antenna ports from the first antenna group, and the third PUSCH layer, the fourth PUSCH layer, and the fifth PUSCH layer are transmitted by antenna ports from the second antenna group; When a rank 6 PUSCH is scheduled for a UE with Ng=2, the first PUSCH layer, the second PUSCH layer, and the third PUSCH layer are transmitted by antenna ports from the first antenna group, and the fourth PUSCH layer, the fifth PUSCH layer, and the sixth PUSCH layer are transmitted by antenna ports from the second antenna group; When a rank 7 PUSCH is scheduled for a UE with Ng=2, the first PUSCH layer, the second PUSCH layer, and the third PUSCH layer are transmitted by antenna ports from the first antenna group, and the fourth PUSCH layer, the fifth PUSCH layer, the sixth PUSCH layer, and the seventh PUSCH layer are transmitted by antenna ports from the second antenna group; as well as When rank 8 PUSCH is scheduled for UE with Ng=2, the first PUSCH layer, the second PUSCH layer, the third PUSCH layer and the fourth PUSCH layer are transmitted by the antenna ports from the first antenna group, and the fifth PUSCH layer, the sixth PUSCH layer, the seventh PUSCH layer and the eighth PUSCH layer are transmitted by the antenna ports from the second antenna group.

10. A method performed at a user equipment (UE), comprising: Receiving a DCI that schedules a PUSCH, wherein the DCI includes an antenna port field indicating a number of DMRS ports, the number of DMRS ports determining a rank of the scheduled PUSCH, and the DCI further includes a TPMI field indicating one or two precoding matrices; and The precoding matrix for the scheduled PUSCH is determined according to the rank and the one or two precoding matrices.

11. A base station unit, comprising: Transceiver; as well as a processor coupled to the transceiver, wherein the processor is configured to sending, via the transceiver, a DCI for scheduling a PUSCH, wherein the DCI includes an antenna port field indicating a number of DMRS ports, the number of DMRS ports determining a rank of the scheduled PUSCH, and the DCI further includes a TPMI field indicating one or two precoding matrices; and The precoding matrix for the scheduled PUSCH is determined according to the rank and the one or two precoding matrices.

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