Communication method and device, and computer storage medium

Abstract

The embodiment of the invention relates to a communication method, equipment and a computer readable medium. According to an embodiment of the present disclosure, a network device transmits first information associated with at least one first precoding matrix. The network device also provides second information associated with the phase offset information. And the terminal equipment determines a second precoding matrix based on the at least one first precoding matrix and the phase offset information. And the terminal equipment executes transmission to the network equipment on the PUSCH based on the second precoding matrix. In this way, overhead may be reduced.

Description

Technical Field

[0001] Embodiments of the present disclosure generally relate to the field of telecommunications, and in particular, to a communication method, device, and computer storage medium for determining an uplink transmission codebook. Background Art

[0002] Several techniques have been proposed to improve communication performance. For example, multiple-input multiple-output (MIMO) has been proposed. MIMO includes features that help utilize a large number of antenna elements at a base station for both frequency bands below 6 GHz and above 6 GHz. In this case, multiple antennas at a transmitter and / or receiver can be used to achieve array and diversity gains rather than capacity gains. In this case, the same symbol weighted by a complex-valued scaling factor is transmitted from each transmit antenna, such that the input covariance matrix has a unit rank. This scheme is called beamforming. When the receiver has multiple antennas, single-layer beamforming cannot simultaneously maximize the signal power at each receive antenna, so precoding is used for multi-layer beamforming to maximize the throughput of a multi-antenna system. Precoding is a general beamforming scheme for supporting multi-layer transmission in a MIMO system. Using precoding, multiple streams are transmitted from the transmit antennas with independent and appropriate weighting for each antenna, such that the throughput is maximized at the receiver output. Summary of the Invention

[0003] Generally, embodiments of the present disclosure provide a method, device, and computer storage medium for communication.

[0004] In a first aspect, a communication method is provided. The method includes: at a terminal device, receiving first information associated with at least one first precoding matrix from a network device; receiving second information associated with a set of phase offsets for at least one first precoding matrix from the network device; determining a second precoding matrix based on the at least one first precoding matrix and the second information; and performing a transmission to the network device on a physical uplink shared channel (PUSCH) based on the second precoding matrix.

[0005] In a second aspect, a communication method is provided. The method includes: at a terminal device, receiving first information associated with a subset of precoding matrices from a network device; receiving second information indicating a precoding matrix in the subset of precoding matrices from the network device, where the bit size for indicating the second information is based on the number of precoding matrices in the subset of first precoding matrices; and performing a transmission to the network device on a physical uplink shared channel (PUSCH) based on the indicated precoding matrix.

[0006] In a third aspect, a communication method is provided. The method includes: at a terminal device, receiving downlink control information including a first field and a second field from a network device, where the first field indicates a first precoding matrix and the second field indicates a parameter based on the first field; determining a second precoding matrix based on the first precoding matrix and the parameter; and performing a transmission to the network device based on the second precoding matrix.

[0007] In a fourth aspect, a communication method is provided. The method includes: at a network device, transmitting first information associated with at least one first precoding matrix to a terminal device; transmitting second information associated with a set of phase offsets for the at least one first precoding matrix to the terminal device; and receiving a transmission on a physical uplink shared channel (PUSCH) from the terminal device, where the transmission is based on a second precoding matrix determined based on the at least one first precoding matrix and the second information.

[0008] In a fifth aspect, a communication method is provided. The method includes: at a network device, transmitting first information associated with a subset of precoding matrices to a terminal device; transmitting second information indicating a precoding matrix in the subset of precoding matrices to the terminal device, where the bit size used to indicate the second information is based on the number of precoding matrices in the subset of precoding matrices; and receiving a transmission on a physical uplink shared channel (PUSCH) from the terminal device, where the transmission is based on the indicated precoding matrix.

[0009] In a sixth aspect, a communication method is provided. The method includes: at a network device, transmitting downlink control information including a first field and a second field to a terminal device, where the first field indicates a first precoding matrix and the second field indicates a parameter based on the first field; and receiving a transmission based on a second precoding matrix from the terminal device, the second precoding matrix being based on the first precoding matrix and the parameter.

[0010] In a seventh aspect, a terminal device is provided. The terminal device includes: at least one processor; and at least one memory coupled to the at least one processor and storing instructions that, when executed by the at least one processor, cause the terminal device to perform the method according to the first aspect, the second aspect, or the third aspect.

[0011] In an eighth aspect, a network device is provided. The network device includes: at least one processor; and at least one memory coupled to the at least one processor and storing instructions that, when executed by the at least one processor, cause the terminal device to perform the method according to the fourth aspect, the fifth aspect, or the sixth aspect.

[0012] In a ninth aspect, there is provided a computer-readable medium having instructions stored thereon that, when executed on at least one processor, cause the at least one processor to perform the methods according to the first aspect, the second aspect, the third aspect, the fourth aspect, the fifth aspect, or the sixth aspect.

[0013] Other features of the present disclosure will become readily apparent from the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The above and other objects, features, and advantages of the present disclosure will become more apparent from the following more detailed description of some embodiments of the present disclosure in the accompanying drawings, in which:

[0015] Figure 1 is a schematic diagram of a communication environment in which embodiments of the present disclosure can be implemented;

[0016] Figure 2 shows a signaling flow for communication according to some embodiments of the present disclosure;

[0017] Figure 3 shows a signaling flow for communication according to some embodiments of the present disclosure;

[0018] Figure 4 shows a signaling flow for communication according to some embodiments of the present disclosure;

[0019] Figure 5 shows a schematic diagram of downlink control information (DCI) according to some embodiments of the present disclosure;

[0020] Figure 6 is a flowchart of an exemplary method according to an embodiment of the present disclosure;

[0021] Figure 7 is a flowchart of an exemplary method according to an embodiment of the present disclosure;

[0022] Figure 8 is a flowchart of an exemplary method according to an embodiment of the present disclosure;

[0023] Figure 9 is a flowchart of an exemplary method according to an embodiment of the present disclosure;

[0024] Figure 10 is a flowchart of an exemplary method according to an embodiment of the present disclosure;

[0025] Figure 11 is a flowchart of an exemplary method according to an embodiment of the present disclosure; and

[0026] Figure 12 is a simplified block diagram of a device suitable for implementing embodiments of the present disclosure.

[0027] Throughout the drawings, the same or similar reference numerals denote the same or similar elements. Detailed Description

[0028] The principles of the present disclosure will now be described with reference to some embodiments. It should be understood that these embodiments are described for illustrative purposes only and help those skilled in the art to understand and implement the present disclosure, without implying any limitation on the scope of the present disclosure. The disclosure described herein can be implemented in various ways other than the ways described below.

[0029] In the following description and claims, unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs.

[0030] As used herein, the term "terminal device" refers to any device having wireless or wired communication capabilities. Examples of terminal devices include, but are not limited to, user equipment (UE), personal computer, desktop computer, mobile phone, cellular phone, smart phone, personal digital assistant (PDA), portable computer, tablet computer, wearable device, Internet of Things (IoT) device, ultra-reliable and low-latency communication (URLLC) device, Internet of Everything (IoE) device, machine type communication (MTC) device, device on a vehicle for V2X communication (where X represents pedestrian, vehicle, or infrastructure / network), device for integrated access and backhaul (IAB), spaceborne vehicle or airborne vehicle in a non-terrestrial network (NTN) including satellites and high-altitude platforms (HAP) containing unmanned aerial vehicle systems (UAS), extended reality (XR) device including different types of reality such as augmented reality (AR), mixed reality (MR), and virtual reality (VR), unmanned aerial vehicle (UAV) commonly referred to as a drone (which is an aircraft without any human pilot), device on a high-speed train (HST), or image acquisition device such as a digital camera, sensor, game device, music storage and playback device, or Internet device implementing wireless or wired Internet access and browsing, etc. The "terminal device" may also have "multicast / broadcast" features to support public safety and critical missions, V2X applications, transparent IPv4 / IPv6 multicast delivery, IPTV, smart TV, radio services, software delivery over wireless, group communication, and IoT applications. It may also incorporate one or more subscriber identity modules (SIM), referred to as multi-SIM. The term "terminal device" may be used interchangeably with UE, mobile station, subscriber station, mobile terminal, user terminal, or wireless device.

[0031] The term "network device" refers to a device that can provide or host a cell or coverage area in which terminal devices can communicate. Examples of network devices include, but are not limited to, Node B (Node B or NB), evolved Node B (eNode B or eNB), next-generation Node B (gNB), transmission and reception point (TRP), remote radio unit (RRU), radio head (RH), remote radio head (RRH), IAB node, low-power nodes (such as femto nodes, pico nodes), reconfigurable intelligent surface (RIS), etc.

[0032] The terminal device or network device may have artificial intelligence (AI) or machine learning capabilities. It typically includes a model that has been trained from a large amount of collected data for a specific function and can be used to predict some information.

[0033] The terminal device or network device may operate in several frequency ranges, for example, FR1 (e.g., 450 MHz to 7125 MHz), FR2 (24.25 GHz to 71 GHz), FR2-2 (52.6 GHz to 71 GHz), frequency bands greater than 100 GHz, and terahertz (THz). The terminal device or network device may also operate on licensed / unlicensed / shared spectrum. The terminal device may have more than one connection with the network device in a multi-radio dual-connection (MR-DC) application scenario. The terminal device or network device may operate in full-duplex mode, flexible-duplex mode, and cross-duplex mode.

[0034] Embodiments of the present disclosure may be executed in test devices, such as signal generators, signal analyzers, spectrum analyzers, network analyzers, test terminal devices, test network devices, channel simulators.

[0035] In some embodiments, the terminal device may be connected to a first network device and a second network device. One of the first network device and the second network device may be a master node, and the other network device may be a secondary node. The first network device and the second network device may use different radio access technologies (RATs). In some embodiments, the first network device may be a first RAT device, and the second network device may be a second RAT device. In some embodiments, the first RAT device is an eNB, and the second RAT device is a gNB. Information related to different RATs may be transmitted to the terminal device from at least one of the first network device or the second network device. In some embodiments, first information may be transmitted from the first network device to the terminal device, and second information may be transmitted to the terminal device directly or via the first network device from the second network device. In some embodiments, information related to the configuration for the terminal device configured by the second network device may be transmitted via the first network device from the second network device. Information related to the reconfiguration for the terminal device configured by the second network device may be sent to the terminal device directly or via the first network device from the second network device.

[0036] As used herein, the singular forms "a", "an" and "the" are also intended to include the plural forms unless the context clearly dictates otherwise. The term "comprising" and its variants should be understood as open terms meaning "including but not limited to". The term "based on" should be understood as "at least partially based on". The terms "one embodiment" and "embodiment" should be understood as "at least one embodiment". The term "another embodiment" should be understood as "at least one other embodiment". The terms "first", "second", etc. may refer to different or the same objects. Other definitions, whether explicit or implicit, may be included below.

[0037] In some examples, a value, process or device is referred to as "optimal", "lowest", "highest", "minimum", "maximum", etc. It should be understood that such descriptions are intended to indicate that a choice can be made among many alternative functions in use, and such a choice does not necessarily need to be better, smaller, higher or otherwise superior to other choices.

[0038] In the context of the present application, the terms "transmission occasion", "reception occasion", "repetition", "transmission", "reception", "PDSCH transmission occasion", "PDSCH repetition", "PUSCH transmission occasion", "PUSCH repetition", "PUCCH occasion", "PUCCH repetition", "repetitive transmission", "repetitive reception", "PDSCH transmission", "PDSCH reception", "PUSCH transmission", "PUSCH reception", "PUCCH transmission", "PUCCH reception", "RS transmission", "RS reception", "communication", "transmission" and "reception" may be used interchangeably. The terms "TCI state", "set of QCL parameters", "(multiple) QCL parameters", "QCL assumption" and "QCL configuration" may be used interchangeably. The terms "TCI field", "TCI state field" and "transmission configuration indication" may be used interchangeably. The terms "transmission occasion", "transmission", "repetition", "reception", "reception occasion", "monitoring occasion", "PDCCH monitoring occasion", "PDCCH transmission occasion", "PDCCH transmission", "PDCCH candidate", "PDCCH reception occasion", "PDCCH reception", "search space", "CORESET", "multiple opportunities" and "PDCCH repetition" may be used interchangeably. Hereinafter, the terms "PDCCH repetition", "repetitive PDCCH", "repetitive PDCCH signal", "PDCCH candidate configured for the same scheduling", "PDCCH", "PDCCH candidate" and "linked PDCCH candidate" may be used interchangeably. The terms "DCI" and "DCI format" may be used interchangeably. In some embodiments, the embodiments of the present disclosure may be applied to PDSCH and PUSCH scheduling, and are described hereinafter by taking PDSCH scheduling as an example. For example, the embodiments in the present disclosure may be applied to PUSCH by replacing "transmission" with "reception" and / or replacing "reception" with "transmission". The terms "PDSCH" and "PUSCH" may be used interchangeably. The terms "transmission" and "reception" may be used interchangeably.The terms "common beam", "common beam update / indication / representation", "unified TCI state", "unified TCI state update / indication / representation", "beam indication", "(multiple) TCI state indication", "TCI_state_r17", "tci_StateId_r17", "TCI_state_r17 indicates the unified TCI state", "TCI state shared / applied for all or a subset of the core set and UE-specific reception on PDSCH", "Release 17 TCI state", "TCI state with tci_StateId_r17", "TCI state configured for TCI state update in the unified TCI framework", "TCI state indicated in DCI for common beam update / indication / representation", and "TCI state indicated in DCI and to be applied to all / subset of the core set and PDSCH" may be used interchangeably. The terms "subset of the core set", "subset of TCI states", "subset of unified TCI states", "downlink (unified) subset of TCI states", and "joint (unified) subset of TCI states" may be used interchangeably. The terms "PUCCH subset", "subset of TCI states", "subset of unified TCI states", "uplink (unified) subset of TCI states", and "joint (unified) subset of TCI states" may be used interchangeably. The terms "precoding matrix", "precoding", "beam", "beamforming", and "precoder" may be used interchangeably. The terms "antenna" and "antenna port" may be used interchangeably. The terms "transmission", "delivery", "Tx", and "TX" may be used interchangeably.

[0039] As described above, precoding is a general beamforming scheme for supporting multi-layer transmission in MIMO systems. Precoding is a technique that utilizes transmit diversity by weighting the information stream, i.e., the transmitter sends the encoded information to the receiver to achieve pre-knowledge of the channel. Using precoding, multiple streams are transmitted from the transmit antennas with independent and appropriate weighting for each antenna, such that the throughput is maximized at the receiver output. The terms "precoding matrix" and "precoder" may be used interchangeably hereinafter. Additionally, uplink transmission with 8 antenna ports can support more than 4 layers.

[0040] According to some solutions, an 8-transmission (TX) uplink (UL) coherent codebook based on two 4TX UL codebooks is proposed. However, it may require large overhead, and in the case of full coherence, many codebooks may not be useful for a given UE. Specifically, for two 4TX codebooks, if There are 1024 precoders. For a given UE (with fully coherent antennas), the number of available precoders is much smaller than the total number, and in fact, the granularity is coarser than that of DFT precoders (with oversampling value > 1). Additionally, for the UL codebook, the timing alignment error (TAE) or phase error between the antennas of the UE can be randomized (for different UEs), but is fixed (time-invariant) for a given UE (based on QC). Based on the QC solution (considering only units of pi / 2), the phase difference across antennas in units of pi / 2 still cannot satisfy the randomized phase error (-pi, pi).

[0041] Embodiments of the present disclosure provide a scheme for an uplink precoding matrix. According to embodiments of the present disclosure, a network device transmits first information associated with at least one first precoding matrix. The network device also provides second information associated with phase offset information. A terminal device determines a second precoding matrix based on at least one first precoding matrix and the phase offset information. The terminal device performs a transmission to the network device on the PUSCH based on the second precoding matrix. In this way, overhead can be reduced, and TAE can be solved.

[0042] The principles and embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings. Example of a communication network

[0043] Figure 1 A schematic diagram of an example communication network 100 in which some embodiments of the present disclosure can be implemented is shown. As Figure 1 shown, the communication network 100 may include a terminal device 110 and a network device 120. The network device 120 may provide a cell 121 to serve one or more terminal devices. In this example, the terminal device 110 is located in the cell 121 and is served by the network device 120.

[0044] It should be understood that Figure 1 the number of devices and cells in is given for illustrative purposes and does not imply any limitation to the present disclosure. The communication network 100 may include any suitable number of network devices and / or terminal devices and / or cells suitable for implementing the implementations of the present disclosure.

[0045] In some embodiments, the terminal device 110 and the network device 120 may communicate with each other via a channel such as a wireless communication channel on an air interface (e.g., the Uu interface). The wireless communication channel may include a physical uplink control channel (PUCCH), a physical uplink shared channel (PUSCH), a physical random access channel (PRACH), a physical downlink control channel (PDCCH), a physical downlink shared channel (PDSCH), and a physical broadcast channel (PBCH). Of course, any other suitable channel is also feasible.

[0046]

[0046] The communication in the communication network 100 may conform to any suitable standard, including but not limited to Global System for Mobile Communications (GSM), Long Term Evolution (LTE), LTE Evolution, LTE-Advanced (LTE-A), New Radio (NR), Wideband Code Division Multiple Access (WCDMA), Code Division Multiple Access (CDMA), GSM EDGE Radio Access Network (GERAN), Machine Type Communication (MTC), etc. Embodiments of the present disclosure may be implemented according to any generation of communication protocols known currently or developed in the future. Examples of communication protocols include but are not limited to the first generation (1G), second generation (2G), 2.5G, 2.75G, third generation (3G), fourth generation (4G), 4.5G, fifth generation (5G) communication protocols, 5.5G, 5G Advanced Network or sixth generation (6G) network.

[0047]

[0047] In some embodiments, the network device 120 may transmit information to the terminal device 110. The information may indicate that the PUSCH is scheduled to be associated with 8 antenna ports. For example, the total number of antenna ports for PUSCH transmission may be 8. In some embodiments, the information may indicate that the PUSCH is scheduled to be associated with a sounding reference signal (SRS) having 8 antenna ports. In other words, the total number of antenna ports of the SRS associated with the PUSCH transmission is 8. In some embodiments, the information may be transmitted in the SRS configuration.

[0048]

[0048] In some embodiments, for the uplink (UL) codebook, the terminal device 110 may support 1 antenna port or 2 antenna ports or 4 antenna ports or 8 antenna ports. For single-carrier frequency-division multiple access (SC-FDMA) and OFDM, there may be at least one of fully coherent, partially coherent, and non-coherent (antenna selection) codebooks. In some embodiments, for codebook-based UL transmission, the rank indicator (RI) and the precoding matrix indicator (PMI) are jointly encoded, and different numbers of layers (RI values) may be indicated in the same table / field. In some embodiments, for non-codebook-based UL transmission, the RI and the SRS resource indicator are jointly encoded. In some embodiments, for both codebook-based UL transmission and non-codebook-based UL transmission, the number of demodulation reference signal (DMRS) ports is determined based on the number of layers, and the antenna port field (DMRS port) only indicates the (multiple) DMRS port indices.

[0049] As used herein, the term "time slot" refers to a dynamic scheduling unit. A time slot includes a predetermined number of symbols. For example, the number of symbols in a time slot may be 12 or 14. The term "sub - time slot" may refer to a plurality of symbols. For example, the number of symbols in a sub - time slot may be 1, 2, 4, 7, 14. A sub - time slot may include fewer symbols than a time slot. The time slots used herein may refer to normal time slots including a predetermined number of symbols, and may also refer to sub - time slots including fewer symbols than the predetermined number of symbols.

[0050] In some embodiments, the terminal device 110 may be configured or instructed with a number of layers for PUSCH transmission (e.g., denoted as v_ri). For example, the number of layers v_ri may be at least one of {1, 2, 3, 4, 5, 6, 7, 8}. In some embodiments, the terminal device 110 may be configured or instructed with a precoding matrix for PUSCH transmission. In some embodiments, the size of the precoding matrix may be 8*v_ri or v_ri*8. In some embodiments, there may be v_ri columns or rows in the precoding matrix. In some embodiments, in the columns or rows of the precoding matrix, there may be 8 elements, and the index of the elements may be denoted as idx, and idx may be a non - negative integer. For example, 0 <= idx <= 7. Another example, 1 <= idx <= 8.

[0051] In some embodiments, the terminal device 110 may transmit at least one capability information to the network device 120. In some embodiments, the at least one capability information may indicate at least one of the following: support for uplink transmission with 8 antennas or 8 antenna ports, support for PUSCH transmission with 8 antennas or 8 antenna ports, and the capability of the precoding matrix supported by the terminal device 110. In some embodiments, the capability information of the precoding matrix may indicate the type of the precoding matrix supported by the terminal device 110. In some embodiments, the capability information of the precoding matrix may include at least one of the following: support for at least one full coherence of 8 transmission (Tx) precoders, support for at least one partial coherence of 8 Tx precoders, support for at least one first full coherence of 8 Tx precoders, support for at least one second full coherence of 8 Tx precoders, support for at least one first partial coherence of 8 Tx precoders, support for at least one second partial coherence of 8 Tx precoders, and support for at least one incoherence of 8 Tx precoders. In some embodiments, for the first partial coherence, the 8 antennas may include two groups, and each group may include 4 antennas, and the 4 antennas in one group may be coherent with each other. For example, the antennas in different groups may not be coherent or may be incoherent. In some embodiments, for the second partial coherence, the 8 antennas may include four groups, and each group may include 2 antennas, and the 2 antennas in one group may be coherent with each other. For example, the antennas in different groups may not be coherent or may be incoherent. In some embodiments, for the incoherence, the 8 antennas may not be coherent with each other or may be non-coherent with each other.

[0052] In some embodiments, there may be at least one precoder for 8Tx. In some embodiments, the at least one precoder for 8Tx may include at least one of the following: at least one full coherence 8Tx precoder, at least one first full coherence 8Tx precoder, at least one second full coherence 8Tx precoder, at least one partial coherence 8Tx precoder, at least one first partial coherence 8Tx precoder, at least one second partial coherence 8Tx precoder, and at least one incoherence 8Tx precoder.

[0053] In some embodiments, the size of the at least one precoder may be 8*v_ri or v_ri*8. In some embodiments, there may be v_ri columns or rows in each precoder of the at least one precoder. In some embodiments, in each column or row of the at least one precoder, there may be 8 elements, and the index of the element may be represented as idx, and idx may be a non-negative integer. For example, 0 <= idx <= 7. Another example is 1 <= idx <= 8.

[0054] In some embodiments, there may be eight antennas for eight - antenna transmission or 8Tx, and the indices of the eight antennas may be represented as {AP0, AP1, AP2, AP3, AP4, AP5, AP6, AP7}. In some embodiments, when there are two antenna groups (e.g., a first antenna group with four antennas and a second antenna group with four antennas), each antenna group includes 4 antennas. In some embodiments, when there are four antenna groups (e.g., a first antenna group with 2 antennas, a second antenna group with 2 antennas, a third antenna group with 2 antennas, and a fourth antenna group with 2 antennas), each antenna group includes 2 antennas.

[0055] In some embodiments, an index of each element in a column or a row of a column or a row in each precoder of at least one precoder may be associated with an index of one of the eight antennas. In some embodiments, the first element or the index of the first element in a column or a row of a column or a row in each precoder of at least one precoder may be associated with AP0. In some embodiments, the second element or the index of the second element in a column or a row of a column or a row in each precoder of at least one precoder may be associated with AP1. In some embodiments, the third element or the index of the third element in a column or a row of a column or a row in each precoder of at least one precoder may be associated with AP2. In some embodiments, the fourth element or the index of the fourth element in a column or a row of a column or a row in each precoder of at least one precoder may be associated with AP3. In some embodiments, the fifth element or the index of the fifth element in a column or a row of a column or a row in each precoder of at least one precoder may be associated with AP4. In some embodiments, the sixth element or the index of the sixth element in a column or a row of a column or a row in each precoder of at least one precoder may be associated with AP5. In some embodiments, the seventh element or the index of the seventh element in a column or a row of a column or a row in each precoder of at least one precoder may be associated with AP6. In some embodiments, the eighth element or the index of the eighth element in a column or a row of a column or a row in each precoder of at least one precoder may be associated with AP7.

[0056] In some embodiments, for the uplink (UL) codebook, the terminal device 110 may support 1 antenna port or 2 antenna ports or 4 antenna ports or 8 antenna ports. For single-carrier frequency-division multiple access (SC-FDMA) and OFDM, there may be at least one of fully coherent, partially coherent, and non-coherent (antenna selection) codebooks. In some embodiments, for codebook-based UL transmission, the rank indicator (RI) and the precoding matrix indicator (PMI) are jointly encoded, and different numbers of layers (RI values) may be indicated in the same table / field. In some embodiments, for non-codebook-based UL transmission, the RI and the SRS resource indicator are jointly encoded. In some embodiments, for both codebook-based UL transmission and non-codebook-based UL transmission, the number of demodulation reference signal (DMRS) ports is determined based on the number of layers, and the antenna port field (DMRS ports) only indicates the (multiple) DMRS port indices.

[0057] In some embodiments, there may be at least one fully coherent 8Tx precoder for the terminal device 120. In some embodiments, there may be at least one first fully coherent 8Tx precoder for the terminal device 120. In some embodiments, there may be at least one second fully coherent 8Tx precoder for the terminal device 120. In some embodiments, there may be at least one partially coherent 8Tx precoder for the terminal device 120. In some embodiments, there may be at least one first partially coherent 8Tx precoder for the terminal device 120. In some embodiments, there may be at least one second partially coherent 8Tx precoder for the terminal device 120. In some embodiments, there may be at least one non-coherent 8Tx precoder for the terminal device 120.

[0058] In some embodiments, the terminal device 120 may indicate or report at least one capability of supporting at least one fully coherent 8Tx precoder. In some embodiments, the terminal device 120 may be configured with at least one fully coherent 8Tx precoder. In some embodiments, the terminal device 120 may be configured with at least one fully coherent 8Tx precoder (or at least one first fully coherent 8Tx precoder or at least one second fully coherent 8Tx precoder) and at least one partially coherent 8Tx precoder and / or at least one non - coherent 8Tx precoder. In some embodiments, the terminal device 120 may be configured with at least one fully coherent 8Tx precoder (or at least one first fully coherent 8Tx precoder or at least one second fully coherent 8Tx precoder) and at least one first partially coherent 8Tx precoder and at least one second partially coherent 8Tx precoder and / or at least one non - coherent 8Tx precoder. In some embodiments, the terminal device 120 may be configured with at least one fully coherent 8Tx precoder (or at least one first fully coherent 8Tx precoder or at least one second fully coherent 8Tx precoder) and at least one first partially coherent 8Tx precoder and / or at least one non - coherent 8Tx precoder. In some embodiments, the terminal device 120 may be configured with at least one fully coherent 8Tx precoder (or at least one first fully coherent 8Tx precoder or at least one second fully coherent 8Tx precoder) and at least one second partially coherent 8Tx precoder and / or at least one non - coherent 8Tx precoder.

[0059] In some embodiments, the terminal device 120 may indicate or report at least one capability of supporting at least one first fully coherent 8Tx precoder. In some embodiments, the terminal device 120 may be configured with at least one first fully coherent 8Tx precoder. In some embodiments, the terminal device 120 may be configured with at least one first fully coherent 8Tx precoder and at least one partially coherent 8Tx precoder and / or at least one non - coherent 8Tx precoder. In some embodiments, the terminal device 120 may be configured with at least one first fully coherent 8Tx precoder and at least one first partially coherent 8Tx precoder and at least one second partially coherent 8Tx precoder and / or at least one non - coherent 8Tx precoder. In some embodiments, the terminal device 120 may be configured with at least one first fully coherent 8Tx precoder and at least one first partially coherent 8Tx precoder and / or at least one non - coherent 8Tx precoder. In some embodiments, the terminal device 120 may be configured with at least one first fully coherent 8Tx precoder and at least one second partially coherent 8Tx precoder and / or at least one non - coherent 8Tx precoder.

[0060] In some embodiments, the terminal device 120 may indicate or report at least one capability of supporting at least one second fully coherent 8Tx precoder. In some embodiments, the terminal device 120 may be configured with at least one second fully coherent 8Tx precoder. In some embodiments, the terminal device 120 may be configured with at least one second fully coherent 8Tx precoder and at least one partially coherent 8Tx precoder and / or at least one non-coherent 8Tx precoder. In some embodiments, the terminal device 120 may be configured with at least one second fully coherent 8Tx precoder, at least one first partially coherent 8Tx precoder, at least one second partially coherent 8Tx precoder, and / or at least one non-coherent 8Tx precoder. In some embodiments, the terminal device 120 may be configured with at least one second fully coherent 8Tx precoder and at least one first partially coherent 8Tx precoder and / or at least one non-coherent 8Tx precoder. In some embodiments, the terminal device 120 may be configured with at least one second fully coherent 8Tx precoder and at least one second partially coherent 8Tx precoder and / or at least one non-coherent 8Tx precoder.

[0061] In some embodiments, the terminal device 120 may indicate or report at least one capability of supporting at least one partially coherent 8Tx precoder. In some embodiments, the terminal device 120 may be configured with at least one partially coherent 8Tx precoder. In some embodiments, the terminal device 120 may be configured with at least one partially coherent 8Tx precoder and / or at least one non-coherent 8Tx precoder. In some embodiments, the terminal device 120 may be configured with at least one first partially coherent 8Tx precoder, at least one second partially coherent 8Tx precoder, and / or at least one non-coherent 8Tx precoder. In some embodiments, the terminal device 120 may be configured with at least one first partially coherent 8Tx precoder and / or at least one non-coherent 8Tx precoder. In some embodiments, the terminal device 120 may be configured with at least one second partially coherent 8Tx precoder and / or at least one non-coherent 8Tx precoder.

[0062] In some embodiments, the terminal device 120 may indicate or report at least one capability of supporting at least one first partial-coherent 8Tx precoder. In some embodiments, the terminal device 120 may be configured with at least one first partial-coherent 8Tx precoder. In some embodiments, the terminal device 120 may be configured with at least one first partial-coherent 8Tx precoder and at least one second partial-coherent 8Tx precoder. In some embodiments, the terminal device 120 may be configured with at least one first partial-coherent 8Tx precoder and / or at least one non-coherent 8Tx precoder. In some embodiments, the terminal device 120 may be configured with at least one first partial-coherent 8Tx precoder and at least one second partial-coherent 8Tx precoder and / or at least one non-coherent 8Tx precoder. In some embodiments, the terminal device 120 may be configured with at least one second partial-coherent 8Tx precoder and / or at least one non-coherent 8Tx precoder.

[0063] In some embodiments, the terminal device 120 may indicate or report at least one capability of supporting at least one second partial-coherent 8Tx precoder. In some embodiments, the terminal device 120 may be configured with at least one second partial-coherent 8Tx precoder. In some embodiments, the terminal device 120 may be configured with at least one first partial-coherent 8Tx precoder and at least one second partial-coherent 8Tx precoder. In some embodiments, the terminal device 120 may be configured with at least one first partial-coherent 8Tx precoder and / or at least one non-coherent 8Tx precoder. In some embodiments, the terminal device 120 may be configured with at least one first partial-coherent 8Tx precoder and at least one second partial-coherent 8Tx precoder and / or at least one non-coherent 8Tx precoder. In some embodiments, the terminal device 120 may be configured with at least one second partial-coherent 8Tx precoder and / or at least one non-coherent 8Tx precoder.

[0064] In some embodiments, the terminal device 120 may indicate or report at least one capability of supporting at least one non-coherent 8Tx precoder. In some embodiments, the terminal device 120 may be configured with at least one non-coherent 8Tx precoder.

[0065] In some embodiments, for each of the full-coherent 8Tx precoders and / or each of the first full-coherent 8Tx precoders and / or each of the second full-coherent 8Tx precoders, 8 elements in each column or each row of the precoding matrix may be non-zero values. For example, the value may be at least one of {1, -1, j, -j} or {1, e j*2π / 8 , e j*2*2π / 8 , e j*3*2π / 8 , e j*4*2π / 8 , ej*5*2π / 8 , e j*6*2π / 8 , e j*7*2π / 8 at least one of}

[0066] In some embodiments, for each of the partially coherent 8Tx precoders and / or for each of the first partially coherent 8Tx precoders, for 8 elements in each column or each row of the precoding matrix, there may be 4 elements with non-zero values and the other 4 elements have a value of 0. For example, the values of the 4 elements with non-zero values may be at least one of {1, -1, j, -j} or {1, e j*2π / 8 , e j*2*2π / 8 , e j*3*2π / 8 , e j*4*2π / 8 , e j*5*2π / 8 , e j*6*2π / 8 , e j*7*2π / 8} at least one of.

[0067] In some embodiments, for each of the partially coherent 8Tx precoders and / or for each of the second partially coherent 8Tx precoders, for 8 elements in each column or each row of the precoding matrix, there may be 2 elements with non-zero values and the other 6 elements have a value of 0. For example, the values of the 2 elements with non-zero values may be at least one of {1, -1, j, -j} or {1, e j*2π / 8 , e j*2*2π / 8 , e j*3*2π / 8 , e j*4*2π / 8 , e j*5*2π / 8 , e j*6*2π / 8 , e j*7*2π / 8} at least one of.

[0068] In some embodiments, for each of the non-coherent 8Tx precoders, for 8 elements in each column or each row of the precoding matrix, there may be only 1 element with a non-zero value and the other 7 elements have a value of 0. For example, the value of the 1 element with a non-zero value may be 1.

[0069] For example, for an 8-transmission (TX) uplink transmission or for a PUSCH transmission associated with an 8-port SRS, there may be a set of precoding matrices. In some embodiments, the set of precoding matrices may include one or more full-phase precoding matrices. Alternatively or additionally, the set of precoding matrices may include one or more partial-phase precoding matrices. Alternatively or additionally, the set of precoding matrices may include one or more non-phase precoding matrices. Alternatively or additionally, the set of precoding matrices may include one or more mixed partial and non-phase precoding matrices. In some embodiments, the set of precoding matrices may include one or more partial-phase precoding matrices. Alternatively or additionally, the set of precoding matrices may include one or more mixed partial and non-phase precoding matrices. Alternatively or additionally, the set of precoding matrices may include one or more non-phase precoding matrices. In some embodiments, the set of precoding matrices may include one or more non-phase precoding matrices.

[0070] In some embodiments, there may be a parameter "N1", and "N1" may represent the number of ports in the first dimension. For example, "N1" may be at least one of {1, 2, 4, 8}. For another example, "N1" may be 2 or 4. In some embodiments, there may be a parameter "N2", and "N2" may represent the number of ports in the second dimension. For example, "N2" may be at least one of {1, 2, 4, 8}. For another example, "N2" may be 1 or 2. In some embodiments, the product of N1 and N2 may be 8. For example, the antenna structure may be a linear array with one dimension. For example, the antenna structure may be a single-polarization configuration. For example, N1 = 1, N2 = 8. For another example, N1 = 2, N2 = 4. For another example, N1 = 4, N2 = 2. For another example, N1 = 8, N2 = 1. In some embodiments, the product of N1 and N2 may be 4. For example, the antenna structure may be a linear array with two dimensions. For example, the antenna structure may be a dual-polarization or cross-polarization configuration. For example, N1 = 1, N2 = 4. For another example, N1 = 2, N2 = 2. For another example, N1 = 4, N2 = 1. In some embodiments, there may be a parameter "O1", and "O1" may represent the first discrete Fourier transform (DFT) oversampling in the first dimension. For example, "O1" may be at least one of {1, 2, 4}. For another example, "O1" may be 2 or 4. In some embodiments, there may be a parameter "O2", and "O2" may represent the second DFT oversampling in the second dimension. For example, "O2" may be at least one of {1, 2, 4}. For another example, "O2" may be 2 or 4. In some embodiments, the first dimension may be the horizontal dimension, and the second dimension may be the vertical dimension. In some embodiments, the first dimension may be the vertical dimension, and the second dimension may be the horizontal dimension. In some embodiments, the first dimension may be the horizontal dimension, and the second dimension may be a vertically inclined dimension. In some embodiments, the first dimension may be a vertically inclined dimension, and the second dimension may be the horizontal dimension.

[0071] In some embodiments, there may be a first vector u m . In some embodiments, u m may be a DFT vector. In some embodiments, if N2 > 1, then In some embodiments, if N2 = 2, then In some embodiments, if N2 = 1, then u m = 1. In some embodiments, m may be a non-negative integer. For example, 0 ≤ m ≤ O2N2. For another example, m may be at least one of {0, 2, 4, 6}. For another example, m may be at least one of {0, 1, 2, 3}. For another example, m may be 0 or 1. For another example, m may be 0 or 1. For another example, m may be 0.

[0072] In some embodiments, there may be a second vector v l,m . In some embodiments, In some embodiments, if N1 = 2 and N2 = 2, then In some embodiments if N1 = 4 and N2 = 1, then In some embodiments, l may be a non - negative integer. For example, 0 ≤ l ≤ O1N1. For another example, l may be at least one of {0, 2, 4, 6}. For another example, l may be at least one of {0, 2, 4, 6, 8, 10, 12, 14}. For another example, l may be at least one of {0, 1, 2, 3}. For another example, l may be 0 or 1. For another example, l may be 0 or 1. For another example, l may be 0. In some embodiments, may represent the transpose of a vector or a matrix.

[0073] In some embodiments, j may be the imaginary unit. In some embodiments, j 2 = - 1. In some embodiments, i may be the imaginary unit. In some embodiments, i 2 = - 1.

[0074] In some embodiments, there may be a factor In some embodiments, In some embodiments, n may be a non - negative integer. For example, n may be at least one of {0, 1, 2, 3}. For another example, n may be 0 or 1. For another example, n may be 0 or 1. For another example, n may be 0.

[0075] In some embodiments, if the terminal device 110 is indicated to have 8 layers, there may be a first set of precoding matrices corresponding to 8 layers (e.g., the first set of full - phase precoding matrices).

[0076] In some embodiments, there may be a first set of vectors corresponding to 1 layer (e.g., denoted as v 4,1,1 ), and the first set of vectors corresponding to 1 layer may be applied to an 8Tx full - phase precoder with 1 layer and / or an 8Tx partial - phase precoder with 1 layer. For example, the 8Tx partial - phase precoder may be the first partial - phase precoder. For example, for the first partial - phase precoder, the 8 Tx antennas may include two groups, and each group may include 4 antennas. For example, the 4 antennas in one group may be coherent. In some embodiments, the first set of vectors corresponding to 1 layer may be at least one of the following: and In some embodiments, the first set of vectors corresponding to layer 1 may be at least one of the following: and In some embodiments, the first set of vectors corresponding to layer 1 may be at least one of the following: and In some embodiments, the number of vectors in the first set of vectors corresponding to layer 1 may be St 1,1 , and St 1,1 may be a positive integer. For example, 1 ≤ St 1,1 ≤ 32. For example, St 1,1 may be 16 or 24. In some embodiments, one vector in the first set of vectors corresponding to layer 1 may be represented as: In some embodiments, s may be a non - negative integer, and 0 ≤ s ≤ St 1,1 - 1. In some embodiments, the value of o 4,1,1 (s,0) and / or the value of p 4,1,1 (s,1) and / or the value of p 4,1,1 (s,2) and / or the value of p 4,1,1 (s,3) may be at least one of {1, - 1, j, - j} or at least one of {1,e j*2π / 8 ,e j*2*2π / 8 ,e j*3*2π / 8 ,e j*4*2π / 8 ,e j*5*2π / 8 ,e j*6*2π / 8 ,e j*7*2π / 8}.

[0077] In some embodiments, at least one fully coherent 8Tx precoder and / or at least one second fully coherent 8Tx precoder may include at least one of the following: In some embodiments, v 4,1,1 (s1) may be a vector from the first set of vectors corresponding to layer 1. In some embodiments, v 4,1,1 (s2) may be a vector from the first set of vectors corresponding to layer 1. In some embodiments, v 4,1,1 (s1) and v 4,1,1 (s2) may be the same or different.

[0078] In some embodiments, may be e j*2π*g / G , and where G may be at least one of {4, 8, 12, 16}, and g may be an integer from 0 to G - 1.

[0079] In some embodiments, the first antenna group having 4 antennas may include antennas having {AP0, AP2, AP4, AP6}, and the second antenna group having 4 antennas may include antennas having {AP1, AP3, AP5, AP7}. In some embodiments, at least one full-coherence 8Tx precoder and / or at least one second full-coherence 8Tx precoder may include at least one of the following:

[0080] In some embodiments, the first antenna group having 4 antennas may include antennas having {AP0, AP1, AP4, AP5}, and the second antenna group having 4 antennas may include antennas having {AP2, AP3, AP6, AP7}. In some embodiments, at least one full-coherence 8Tx precoder and / or at least one second full-coherence 8Tx precoder may include at least one of the following:

[0081] In some embodiments, the first antenna group having 4 antennas may include antennas having {AP0, AP1, AP2, AP3}, and the second antenna group having 4 antennas may include antennas having {AP4, AP5, AP6, AP7}. In some embodiments, at least one full-coherence 8Tx precoder and / or at least one second full-coherence 8Tx precoder may include at least one of the following:

[0082] In some embodiments, at least one partial-coherence 8Tx precoder and / or at least one first partial-coherence 8Tx precoder may include at least one of the following: and In some embodiments, v 4,1,1 (s1) may be a vector from the first set of vectors corresponding to layer 1. In some embodiments, and / or The "0" in may represent a vector having 4 elements. For example, the vector [0, 0, 0, 0] T . In some embodiments, for the first set of antennas or when the first set of antennas is configured or indicated, at least one partial-coherence 8Tx precoder and / or at least one first partial-coherence 8Tx precoder may include at least one of the following: In some embodiments, for the second set of antennas or when the second set of antennas is configured or indicated, at least one partial-coherence 8Tx precoder and / or at least one first partial-coherence 8Tx precoder may include at least one of the following:

[0083] In some embodiments, the first antenna group having 4 antennas may include antennas having {AP0, AP2, AP4, AP6}, and the second antenna group having 4 antennas may include antennas having {AP1, AP3, AP5, AP7}. In some embodiments, at least one partially coherent 8Tx precoder and / or at least one first partially coherent 8Tx precoder may include at least one of the following: and In some embodiments, for the first group of antennas or when the first group of antennas is configured or indicated, at least one partially coherent 8Tx precoder and / or at least one first partially coherent 8Tx precoder may include at least one of the following: In some embodiments, for the second group of antennas or when the second group of antennas is configured or indicated, at least one partially coherent 8Tx precoder and / or at least one first partially coherent 8Tx precoder may include at least one of the following:

[0084] In some embodiments, the first antenna group having 4 antennas may include antennas having {AP0, AP1, AP4, AP5}, and the second antenna group having 4 antennas may include antennas having {AP2, AP3, AP6, AP7}. In some embodiments, at least one partially coherent 8Tx precoder and / or at least one first partially coherent 8Tx precoder may include at least one of the following: and In some embodiments, for the first group of antennas or when the first group of antennas is configured or indicated, at least one partially coherent 8Tx precoder and / or at least one first partially coherent 8Tx precoder may include at least one of the following: In some embodiments, for the second group of antennas or when the second group of antennas is configured or indicated, at least one partially coherent 8Tx precoder and / or at least one first partially coherent 8Tx precoder may include at least one of the following:

[0085] In some embodiments, the first antenna group having 4 antennas may include antennas having {AP0, AP1, AP2, AP3}, and the second antenna group having 4 antennas may include antennas having {AP4, AP5, AP6, AP7}. In some embodiments, at least one partially coherent 8Tx precoder and / or at least one first partially coherent 8Tx precoder may include at least one of the following: and In some embodiments, for the first set of antennas or when the first set of antennas is configured or indicated, at least one partially coherent 8Tx precoder and / or at least one first partially coherent 8Tx precoder may include at least one of the following: In some embodiments, for the second set of antennas or when the second set of antennas is configured or indicated, at least one partially coherent 8Tx precoder and / or at least one first partially coherent 8Tx precoder may include at least one of the following:

[0086] In some embodiments, s1 may be a non - negative integer, and 0 ≤ s1 ≤ St 1,1 −1. In some embodiments, s2 may be a non - negative integer, and 0 ≤ s2 ≤ St 1,1 −1.

[0087] In some embodiments, there may be a second set of vectors corresponding to 1 layer (e.g., denoted as v 4,1,2 ), and the second set of vectors corresponding to 1 layer may be applied to an 8Tx partially coherent precoder with 1 layer. For example, the 8Tx partially coherent precoder may be a first partially coherent precoder and / or a second partially coherent precoder. For example, for the first partially coherent precoder, the 8 Tx antennas may include two groups, and each group may include 4 antennas. For example, the 4 antennas in one group may be coherent. Also for example, for the second partially coherent precoder, the 8 Tx antennas may include four groups, and each group may include 2 antennas. For example, the 2 antennas in one group may be coherent. In some embodiments, the second set of vectors corresponding to 1 layer may be at least one of the following: and In some embodiments, the number of vectors in the second set of vectors corresponding to 1 layer may be St 1,2 , and St 1,2 may be a positive integer. For example, 1 ≤ St 1,2 ≤ 16. For example, St 1,2 may be 4 or 8 or 16. In some embodiments, one vector in the second set of vectors corresponding to 1 layer may be represented as: In some embodiments, s 4,1,2 may be a non - negative integer, and 0 ≤ s 4,1,2 ≤ St 1,2 −1. In some embodiments, p 4,1,2 (s4,1,2 , 0) value and / or p 4,1,2 (s 4,1,2 , 1) value and / or p 4,1,2 (s 4,1,2 , 2) value and / or p 4,1,2 (s 4,1,2 , 3) values, two of which can be at least one of {1, -1, j, -j} or at least one of {1, e j*2π / 8 , e j*2*2π / 8 , e j*3*2π / 8 , e j*4*2π / 8 , e j*5*2π / 8 , e j*6*2π / 8 , e j*7*2π / 8}. In some embodiments, p 4,1,2 (s 4,1,2 , 0) value and / or p 4,1,2 (s 4,1,2 , 1) value and / or p 4,1,2 (s 4,1,2 , 2) value and / or p 4,1,2 (s 4,1,2 , 3) values, and the other two of which can be 0.

[0088] In some embodiments, at least one partially coherent 8Tx precoder and / or at least one first partially coherent 8Tx precoder may include at least one of the following: In some embodiments, v 4,1,2 (s 4,1,2,1 ) may be a vector from a second set of vectors corresponding to layer 1. In some embodiments, v 4,1,2 (s 4,1,2,2 ) may be a vector from a second set of vectors corresponding to layer 1. In some embodiments, v 4,1,2 (s 4,1,2,1 ) and v 4,1,2 (s 4,1,2,2 ) may be the same or different.

[0089] In some embodiments, may be e j*2π*g / G and where G may be at least one of {4, 8, 12, 16}, and g may be an integer from 0 to G - 1.

[0090] In some embodiments, the first antenna group having 4 antennas may include antennas having {AP0, AP2, AP4, AP6}, and the second antenna group having 4 antennas may include antennas having {AP1, AP3, AP5, AP7}. In some embodiments, at least one partially coherent 8Tx precoder and / or at least one first partially coherent 8Tx precoder may include at least one of the following:

[0091] In some embodiments, the first antenna group having 4 antennas may include antennas having {AP0, AP1, AP4, AP5}, and the second antenna group having 4 antennas may include antennas having {AP2, AP3, AP6, AP7}. In some embodiments, at least one partially coherent 8Tx precoder and / or at least one first partially coherent 8Tx precoder may include at least one of the following:

[0092] In some embodiments, the first antenna group having 4 antennas may include antennas having {AP0, AP1, AP2, AP3}, and the second antenna group having 4 antennas may include antennas having {AP4, AP5, AP6, AP7}. In some embodiments, at least one partially coherent 8Tx precoder and / or at least one first partially coherent 8Tx precoder may include at least one of the following:

[0093] In some embodiments, at least one partially coherent 8Tx precoder and / or at least one second partially coherent 8Tx precoder may include at least one of the following: and In some embodiments, v 4,1,2 (s 4,1,2,1 ) may be a vector from a second set of vectors corresponding to 1 layer. In some embodiments, and the "0" in may represent a vector having 4 elements. For example, the vector [0, 0, 0, 0]T. In some embodiments, for the first set of antennas or the first set of antennas is configured or indicated, at least one partially coherent 8Tx precoder and / or at least one second partially coherent 8Tx precoder may include at least one of the following: In some embodiments, for the second set of antennas or the second set of antennas is configured or indicated, at least one partially coherent 8Tx precoder and / or at least one second partially coherent 8Tx precoder may include at least one of the following:

[0094] In some embodiments, the first antenna group having 4 antennas may include antennas having {AP0, AP2, AP4, AP6}, and the second antenna group having 4 antennas may include antennas having {AP1, AP3, AP5, AP7}. In some embodiments, at least one partially coherent 8Tx precoder and / or at least one second partially coherent 8Tx precoder may include at least one of the following: and In some embodiments, for a first set of antennas or when the first set of antennas is configured or instructed, at least one partially coherent 8Tx precoder and / or at least one second partially coherent 8Tx precoder may include at least one of the following: In some embodiments, for a second set of antennas or when the second set of antennas is configured or instructed, at least one partially coherent 8Tx precoder and / or at least one second partially coherent 8Tx precoder may include at least one of the following:

[0095] In some embodiments, a first set of antennas having 4 antennas may include antennas having {AP0, AP1, AP4, AP5}, and a second set of antennas having 4 antennas may include antennas having {AP2, AP3, AP6, AP7}. In some embodiments, at least one partially coherent 8Tx precoder and / or at least one second partially coherent 8Tx precoder may include at least one of the following: and In some embodiments, for a first set of antennas or when the first set of antennas is configured or instructed, at least one partially coherent 8Tx precoder and / or at least one second partially coherent 8Tx precoder may include at least one of the following: In some embodiments, for a second set of antennas or when the second set of antennas is configured or instructed, at least one partially coherent 8Tx precoder and / or at least one second partially coherent 8Tx precoder may include at least one of the following:

[0096] In some embodiments, a first set of antennas having 4 antennas may include antennas having {AP0, AP1, AP2, AP3}, and a second set of antennas having 4 antennas may include antennas having {AP4, AP5, AP6, AP7}. In some embodiments, at least one partially coherent 8Tx precoder and / or at least one second partially coherent 8Tx precoder may include at least one of the following: and In some embodiments, for the first set of antennas or when the first set of antennas is configured or instructed, at least one partially coherent 8Tx precoder and / or at least one second partially coherent 8Tx precoder may include at least one of the following: In some embodiments, for the second set of antennas or when the second set of antennas is configured or instructed, at least one partially coherent 8Tx precoder and / or at least one second partially coherent 8Tx precoder may include at least one of the following:

[0097] In some embodiments, s 4,1,2,1 may be a non - negative integer, and 0 ≤ s 4,1,2,1 ≤ St 1,2 −1. In some embodiments, s 4,1,2,2 may be a non - negative integer, and 0 ≤ s 4,1,2,2 ≤ St 1,2 −1.

[0098] In some embodiments, there may be a third set of vectors corresponding to layer 1 (e.g., denoted as v 4,1,3 ), and the third set of vectors corresponding to layer 1 can be applied to an 8Tx partially coherent precoder with layer 1 and / or an 8Tx non - coherent precoder with layer 1. For example, the 8Tx partially coherent precoder can be a second partially coherent precoder. For example, for the second partially coherent precoder, the 8 Tx antennas can include four groups, and each group can include 2 antennas. For example, the 2 antennas in a group can be coherent. In some embodiments, the third set of vectors corresponding to layer 1 may be at least one of the following: and In some embodiments, the number of vectors in the third set of vectors corresponding to layer 1 can be St 1,3 , and St 1,3 can be a positive integer. For example, 1 ≤ St 1,3 ≤ 4. For example, St 1,3 can be 2 or 4 or. In some embodiments, one vector in the third set of vectors corresponding to layer 1 can be represented as: In some embodiments, s 4,1,3 may be a non - negative integer, and 0 ≤ s 4,1,3 ≤ St 1,3 −1. In some embodiments, the value of p 4,1,3 (s 4,1,3 ,0) and / or the value of p 4,1,3 (s 4,1,3 ,1) and / or the value of p4,1,3 (s 4,1,3 , 2) and / or the value of p 4,1,3 (s 4,1,3 , 3) can be 1. In some embodiments, p 4,1,3 (s 4,1,3 , 0) and / or the value of p 4,1,3 (s 4,1,3 , 1) and / or the value of p 4,1,3 (s 4,1,3 , 2) and / or the value of p 4,1,3 (s 4,1,3 , 3) of the other three values can be 0.

[0099] In some embodiments, at least one partial coherent 8Tx precoder and / or at least one second partial coherent 8Tx precoder may include at least one of the following: In some embodiments, v 4,1,3 (s 4,1,3,1 ) can be a vector from a third set of vectors corresponding to layer 1. In some embodiments, v 4,1,3 (s 4,1,3,2 ) can be a vector from a third set of vectors corresponding to layer 1. In some embodiments, v 4,1,3 (s 4,1,3,1 ) and v 4,1,3 (s 4,1,3,2 ) can be the same or different.

[0100] In some embodiments, can be e j*2π*g / G , and where G can be at least one of {4, 8, 12, 16}, and g can be an integer from 0 to G - 1.

[0101] In some embodiments, the first antenna group with 4 antennas may include antennas with {AP0, AP2, AP4, AP6}, and the second antenna group with 4 antennas may include antennas with {AP1, AP3, AP5, AP7}. In some embodiments, at least one partial coherent 8Tx precoder and / or at least one second partial coherent 8Tx precoder may include at least one of the following:

[0102] In some embodiments, the first antenna group with 4 antennas may include antennas with {AP0, AP1, AP4, AP5}, and the second antenna group with 4 antennas may include antennas with {AP2, AP3, AP6, AP7}. In some embodiments, at least one partial coherent 8Tx precoder and / or at least one second partial coherent 8Tx precoder may include at least one of the following:

[0103] In some embodiments, the first antenna group having 4 antennas may include antennas having {AP0, AP1, AP2, AP3}, and the second antenna group having 4 antennas may include antennas having {AP4, AP5, AP6, AP7}. In some embodiments, at least one partially coherent 8Tx precoder and / or at least one second partially coherent 8Tx precoder may include at least one of the following:

[0104] In some embodiments, at least one non - coherent 8Tx precoder may include at least one of the following: And In some embodiments, v 4,1,3 (s 4,1,3,1 ) may be a vector from a third group of vectors corresponding to layer 1. In some embodiments, And The "0" in may represent a vector having 4 elements. For example, the vector [0, 0, 0, 0] T . In some embodiments, for the first group of antennas or when the first group of antennas is configured or indicated, at least one non - coherent 8Tx precoder may include at least one of the following: In some embodiments, for the second group of antennas or when the second group of antennas is configured or indicated, at least one non - coherent 8Tx precoder may include at least one of the following:

[0105] In some embodiments, the first antenna group having 4 antennas may include antennas having {AP0, AP2, AP4, AP6}, and the second antenna group having 4 antennas may include antennas having {AP1, AP3, AP5, AP7}. In some embodiments, at least one non - coherent 8Tx precoder may include at least one of the following: And In some embodiments, for the first group of antennas or when the first group of antennas is configured or indicated, at least one non - partially coherent 8Tx precoder may include at least one of the following: In some embodiments, for the second group of antennas or when the second group of antennas is configured or indicated, at least one non - coherent 8Tx precoder may include at least one of the following:

[0106] In some embodiments, a first antenna group having 4 antennas may include antennas having {AP0, AP1, AP4, AP5}, and a second antenna group having 4 antennas may include antennas having {AP2, AP3, AP6, AP7}. In some embodiments, at least one non-coherent 8Tx precoder may include at least one of the following: and In some embodiments, for the first set of antennas or when the first set of antennas is configured or indicated, at least one non-coherent 8Tx precoder may include at least one of the following: In some embodiments, for the second set of antennas or when the second set of antennas is configured or indicated, at least one non-coherent 8Tx precoder may include at least one of the following:

[0107] In some embodiments, a first antenna group having 4 antennas may include antennas having {AP0, AP1, AP2, AP3}, and a second antenna group having 4 antennas may include antennas having {AP4, AP5, AP6, AP7}. In some embodiments, at least one non-coherent 8Tx precoder may include at least one of the following: and In some embodiments, for the first set of antennas or when the first set of antennas is configured or indicated, at least one non-coherent 8Tx precoder may include at least one of the following: In some embodiments, for the second set of antennas or when the second set of antennas is configured or indicated, at least one non-coherent 8Tx precoder may include at least one of the following:

[0108] In some embodiments, s 4,1,3,1 can be a non-negative integer, and 0 ≤ s 4,1,3,1 ≤ St 1,3 −1. In some embodiments, s 4,1,3,2 can be a non-negative integer, and 0 ≤ s 4,1,3,2 ≤ St 1,3 −1.

[0109] In some embodiments, there may be a fourth set of vectors corresponding to layer 1 (e.g., denoted as v4,1,4 ), and the fourth set of vectors corresponding to layer 1 can be applied to an 8Tx full-phase interference encoder with 1 layer and / or an 8Tx second full-phase interference encoder and / or an 8Tx partial-phase interference encoder and / or an 8Tx first partial-phase interference encoder and / or an 8Tx second partial-phase interference encoder. For example, for the first partial-phase interference encoder, the 8 Tx antennas can include two groups, and each group can include 4 antennas. For example, the 4 antennas in one group can be coherent. Also for example, for the second partial-phase interference encoder, the 8 Tx antennas can include four groups, and each group can include 2 antennas. For example, the 2 antennas in one group can be coherent. In some embodiments, the fourth set of vectors corresponding to layer 1 can be at least one of the following: and In some embodiments, the number of vectors in the fourth set of vectors corresponding to layer 1 can be St 1,4 , and St 1,4 can be a positive integer. For example, 1 ≤ St 1,4 ≤ 4. For example, St 1,4 can be 2 or 4. In some embodiments, one vector in the fourth set of vectors corresponding to layer 1 can be represented as: In some embodiments, s 4,1,4 can be a non-negative integer, and 0 ≤ s 4,1,4 ≤ St 1,4 -1. In some embodiments, the value of p 4,1,4 (s 4,1,4 , 0) and / or the value of p 4,1,4 (s 4,1,4 , 1) can be at least one of {1, -1, j, -j} or at least one of {1, e j*2π / 8 , e j*2*2π / 8 , e j*3*2π / 8 , e j*4*2π / 8 , e j*5*2π / 8 , e j*6*2π / 8 , e j*7*2π / 8}.

[0110] In some embodiments, at least one fully coherent 8Tx precoder and / or at least one second fully coherent 8Tx precoder can include at least one of the following: In some embodiments, v 4,1,4 (s 4,1,4,1 ) and / or v 4,1,4 (s 4,1,4,2 ) and / or v 4,1,4 (s 4,1,4,3 ) and / or v 4,1,4 (s 4,1,4,4) can be a vector from the fourth set of vectors corresponding to layer 1. In some embodiments, v 4,1,4 (s 4,1,4,1 ) and / or v 4,1,4 (s 4,1,4,2 ) and / or v 4,1,4 (s 4,1,4,3 ) and / or v 4,1,4 (s 4,1,4,4 ) can be the same as or different from each other.

[0111] In some embodiments, can be e j*2π*g1 / G , and where G can be at least one of {4, 8, 12, 16}, and g1 can be an integer from 0 to G - 1. In some embodiments, can be e j*2π*g2 / G , and where G can be at least one of {4, 8, 12, 16}, and g2 can be an integer from 0 to G - 1. In some embodiments, can be e j *2π*g3 / G , and where G can be at least one of {4, 8, 12, 16}, and g3 can be an integer from 0 to G - 1.

[0112] In some embodiments, the first antenna group with 2 antennas can include antennas with {AP0, AP4}, and the second antenna group with 2 antennas can include antennas with {AP1, AP5}, and the third antenna group with 2 antennas can include antennas with {AP2, AP6}, and the fourth antenna group with 2 antennas can include antennas with {AP3, AP7}. In some embodiments, at least one full - coherence 8Tx precoder and / or at least one second full - coherence 8Tx precoder can include at least one of the following:

[0113] In some embodiments, the first antenna group with 2 antennas can include antennas with {AP0, AP1}, and the second antenna group with 2 antennas can include antennas with {AP2, AP3}, and the third antenna group with 2 antennas can include antennas with {AP4, AP5}, and the fourth antenna group with 2 antennas can include antennas with {AP6, AP7}. In some embodiments, at least one full - coherence 8Tx precoder and / or at least one second full - coherence 8Tx precoder can include at least one of the following:

[0114] In some embodiments, the first antenna group with 2 antennas may include antennas with {AP0, AP2}, the second antenna group with 2 antennas may include antennas with {AP4, AP6}, the third antenna group with 2 antennas may include antennas with {AP1, AP5}, and the fourth antenna group with 2 antennas may include antennas with {AP3, AP7}. In some embodiments, at least one fully coherent 8Tx precoder and / or at least one second fully coherent 8Tx precoder may include at least one of the following:

[0115] In some embodiments, at least one partially coherent 8Tx precoder and / or at least one second partially coherent 8Tx precoder may include at least one of the following: and In some embodiments, v 4,1,4 (s 4,1,4,1 ) may be a vector from the fourth set of vectors corresponding to layer 1. In some embodiments, and the "0" in represents a vector with 6 elements. For example, the vector [0, 0, 0, 0, 0, 0] T . In some embodiments, for the first set of antennas with 2 antennas or the first set of antennas with 2 antennas is configured or indicated, at least one partially coherent 8Tx precoder and / or at least one second partially coherent 8Tx precoder may include at least one of the following: In some embodiments, for the fourth set of antennas with 2 antennas or the fourth set of antennas with 2 antennas is configured or indicated, at least one partially coherent 8Tx precoder and / or at least one second partially coherent 8Tx precoder may include at least one of the following:

[0116] In some embodiments, the first antenna group with 2 antennas may include antennas with {AP0, AP4}, the second antenna group with 2 antennas may include antennas with {AP1, AP5}, the third antenna group with 2 antennas may include antennas with {AP2, AP6}, and the fourth antenna group with 2 antennas may include antennas with {AP3, AP7}. In some embodiments, at least one partially coherent 8Tx precoder and / or at least one second partially coherent 8Tx precoder may include at least one of the following: and In some embodiments, for a first set of antennas having 2 antennas or a first set of antennas having 2 antennas is configured or instructed, at least one partially coherent 8Tx precoder and / or at least one second partially coherent 8Tx precoder may include at least one of the following: In some embodiments, for a second set of antennas having 2 antennas or a second set of antennas having 2 antennas is configured or instructed, at least one partially coherent 8Tx precoder and / or at least one second partially coherent 8Tx precoder may include at least one of the following: In some embodiments, for a third set of antennas having 2 antennas or a third set of antennas having 2 antennas is configured or instructed, at least one partially coherent 8Tx precoder and / or at least one second partially coherent 8Tx precoder may include at least one of the following: In some embodiments, for a fourth set of antennas having 2 antennas or a third set of antennas having 2 antennas is configured or instructed, at least one partially coherent 8Tx precoder and / or at least one second partially coherent 8Tx precoder may include at least one of the following:

[0117] In some embodiments, the first set of antennas having 2 antennas may include antennas having {AP0, AP1}, and the second set of antennas having 2 antennas may include antennas having {AP2, AP3}, and the third set of antennas having 2 antennas may include antennas having {AP4, AP5}, and the fourth set of antennas having 2 antennas may include antennas having {AP6, AP7}. In some embodiments, at least one partially coherent 8Tx precoder and / or at least one second partially coherent 8Tx precoder may include at least one of the following: and In some embodiments, for a first set of antennas having 2 antennas or a first set of antennas having 2 antennas is configured or instructed, at least one partially coherent 8Tx precoder and / or at least one second partially coherent 8Tx precoder may include at least one of the following: In some embodiments, for a second set of antennas having 2 antennas or a second set of antennas having 2 antennas is configured or instructed, at least one partially coherent 8Tx precoder and / or at least one second partially coherent 8Tx precoder may include at least one of the following: In some embodiments, for a third set of antennas having 2 antennas or a third set of antennas having 2 antennas being configured or indicated, at least one partially coherent 8Tx precoder and / or at least one second partially coherent 8Tx precoder may include at least one of the following: In some embodiments, for a fourth set of antennas having 2 antennas or a third set of antennas having 2 antennas being configured or indicated, at least one partially coherent 8Tx precoder and / or at least one second partially coherent 8Tx precoder may include at least one of the following:

[0118] In some embodiments, the first set of antennas having 2 antennas may include antennas having {AP0, AP2}, the second set of antennas having 2 antennas may include antennas having {AP4, AP6}, the third set of antennas having 2 antennas may include antennas having {AP1, AP5}, and the fourth set of antennas having 2 antennas may include antennas having {AP3, AP7}. In some embodiments, at least one partially coherent 8Tx precoder and / or at least one second partially coherent 8Tx precoder may include at least one of the following: and In some embodiments, for a first set of antennas having 2 antennas or a first set of antennas having 2 antennas being configured or indicated, at least one partially coherent 8Tx precoder and / or at least one second partially coherent 8Tx precoder may include at least one of the following: In some embodiments, for a second set of antennas having 2 antennas or a second set of antennas having 2 antennas being configured or indicated, at least one partially coherent 8Tx precoder and / or at least one second partially coherent 8Tx precoder may include at least one of the following: In some embodiments, for a third set of antennas having 2 antennas or a third set of antennas having 2 antennas being configured or indicated, at least one partially coherent 8Tx precoder and / or at least one second partially coherent 8Tx precoder may include at least one of the following: In some embodiments, for a fourth set of antennas having 2 antennas or a third set of antennas having 2 antennas being configured or indicated, at least one partially coherent 8Tx precoder and / or at least one second partially coherent 8Tx precoder may include at least one of the following:

[0119] In some embodiments, s 4,1,4,1 can be a non - negative integer, and 0 ≤ s 4,1,4,1 ≤ St 1,4 −1. In some embodiments, s 4,1,4,2 can be a non - negative integer, and 0 ≤ s 4,1,4,2 ≤ St 1,4 −1. In some embodiments, s 4,1,4,3 can be a non - negative integer, and 0 ≤ s 4,1,4,3 ≤ St 1,4 −1. In some embodiments, s 4,1,4,4 can be a non - negative integer, and 0 ≤ s 4,1,4,4 ≤ St 1,4 −1.

[0120] In some embodiments, there can be a fifth set of vectors corresponding to layer 1 (e.g., denoted as v 4,1,5 ), and the fifth set of vectors corresponding to layer 1 can be applied to an 8Tx partial interference encoder with layer 1 and / or an 8Tx first - part partial interference encoder and / or an 8Tx second - part partial interference encoder and / or an 8Tx non - interference encoder. For example, for the first - part partial interference encoder, the 8 Tx antennas can include two groups, and each group can include 4 antennas. For example, the 4 antennas in one group can be coherent. Also for example, for the second - part partial interference encoder, the 8 Tx antennas can include four groups, and each group can include 2 antennas. For example, the 2 antennas in one group can be coherent. In some embodiments, the fifth set of vectors corresponding to layer 1 can be at least one of the following: In some embodiments, the number of vectors in the fifth set of vectors corresponding to layer 1 can be St 1,5 , and St 1,5 can be a positive integer. For example, 1 ≤ St 1,5 ≤ 2. For example, St 1,5 can be 2. In some embodiments, one vector in the fifth set of vectors corresponding to layer 1 can be represented as: In some embodiments, s 4,1,5 can be a non - negative integer, and 0 ≤ s 4,1,5 ≤ St 1,5 −1. In some embodiments, the value of p 4,1,5 (s 4,1,5 ,0) and / or the value of p 4,1,5 (s 4,1,5 ,1) can be 0 or 1.

[0121] In some embodiments, at least one partially coherent 8Tx precoder and / or at least one first partially coherent 8Tx precoder may include at least one of the following: In some embodiments, v 4,1,5 (s 4,1,5,1 ) and / or v 4,1,5 (s 4,1,5,2 ) and / or v 4,1,5 (s 4,1,5,3 ) and / or v 4,1,5 (s 4,1,5,4 ) may be a vector from the fifth group of vectors corresponding to layer 1. In some embodiments, v 4,1,5 (s 4,1,5,1 ) and / or v 4,1,5 (s 4,1,5,2 ) and / or v 4,1,5 (s 4,1,5,3 ) and / or v 4,1,5 (s 4,1,5,4 ) may be the same as or different from each other.

[0122] In some embodiments, may be e j*2π*g1 / G , and where G may be at least one of {4, 8, 12, 16}, and g1 may be an integer from 0 to G - 1. In some embodiments, may be e j*2π*g2 / G , and where G may be at least one of {4, 8, 12, 16}, and g2 may be an integer from 0 to G - 1. In some embodiments, may be e j *2π*g3 / G , and where G may be at least one of {4, 8, 12, 16}, and g3 may be an integer from 0 to G - 1.

[0123] In some embodiments, the first antenna group having 2 antennas may include antennas having {AP0, AP4}, the second antenna group having 2 antennas may include antennas having {AP1, AP5}, the third antenna group having 2 antennas may include antennas having {AP2, AP6}, and the fourth antenna group having 2 antennas may include antennas having {AP3, AP7}. In some embodiments, at least one partially coherent 8Tx precoder and / or at least one first partially coherent 8Tx precoder may include at least one of the following:

[0124] In some embodiments, the first antenna group with 2 antennas may include antennas with {AP0, AP1}, and the second antenna group with 2 antennas may include antennas with {AP2, AP3}, and the third antenna group with 2 antennas may include antennas with {AP4, AP5}, and the fourth antenna group with 2 antennas may include antennas with {AP6, AP7}. In some embodiments, at least one partially coherent 8Tx precoder and / or at least one first partially coherent 8Tx precoder may include at least one of the following:

[0125] In some embodiments, the first antenna group with 2 antennas may include antennas with {AP0, AP2}, and the second antenna group with 2 antennas may include antennas with {AP4, AP6}, and the third antenna group with 2 antennas may include antennas with {AP1, AP5}, and the fourth antenna group with 2 antennas may include antennas with {AP3, AP7}. In some embodiments, at least one partially coherent 8Tx precoder and / or at least one first partially coherent 8Tx precoder may include at least one of the following:

[0126] In some embodiments, at least one non - coherent 8Tx precoder may include at least one of the following: and In some embodiments, v 4,1,5 (s 4,1,5,1 ) may be a vector from the fourth group of vectors corresponding to 1 layer. In some embodiments, and the "0" in may represent a vector with 6 elements. For example, the vector [0, 0, 0, 0, 0, 0] T . In some embodiments, for the first group of antennas with 2 antennas or the first group of antennas with 2 antennas being configured or indicated, at least one non - coherent 8Tx precoder may include at least one of the following: In some embodiments, for the fourth group of antennas with 2 antennas or the fourth group of antennas with 2 antennas being configured or indicated, at least one non - coherent 8Tx precoder may include at least one of the following:

[0127] In some embodiments, the first antenna group with 2 antennas may include antennas with {AP0, AP4}, the second antenna group with 2 antennas may include antennas with {AP1, AP5}, the third antenna group with 2 antennas may include antennas with {AP2, AP6}, and the fourth antenna group with 2 antennas may include antennas with {AP3, AP7}. In some embodiments, at least one non-coherent 8Tx precoder may include at least one of the following: and In some embodiments, for the first group of antennas with 2 antennas or the first group of antennas with 2 antennas is configured or indicated, at least one non-coherent 8Tx precoder may include at least one of the following: In some embodiments, for the second group of antennas with 2 antennas or the second group of antennas with 2 antennas is configured or indicated, at least one non-coherent 8Tx precoder may include at least one of the following: In some embodiments, for the third group of antennas with 2 antennas or the third group of antennas with 2 antennas is configured or indicated, at least one non-coherent 8Tx precoder may include at least one of the following: In some embodiments, for the fourth group of antennas with 2 antennas or the third group of antennas with 2 antennas is configured or indicated, at least one non-coherent 8Tx precoder may include at least one of the following:

[0128] In some embodiments, the first antenna group with 2 antennas may include antennas with {AP0, AP1}, the second antenna group with 2 antennas may include antennas with {AP2, AP3}, the third antenna group with 2 antennas may include antennas with {AP4, AP5}, and the fourth antenna group with 2 antennas may include antennas with {AP6, AP7}. In some embodiments, at least one non-coherent 8Tx precoder may include at least one of the following: and In some embodiments, for the first group of antennas with 2 antennas or the first group of antennas with 2 antennas is configured or indicated, at least one non-coherent 8Tx precoder may include at least one of the following: In some embodiments, for a second set of antennas having 2 antennas or a second set of antennas having 2 antennas is configured or indicated, at least one non-coherent 8Tx precoder may include at least one of the following: In some embodiments, for a third set of antennas having 2 antennas or a third set of antennas having 2 antennas is configured or indicated, at least one non-coherent 8Tx precoder may include at least one of the following: In some embodiments, for a fourth set of antennas having 2 antennas or a fourth set of antennas having 2 antennas is configured or indicated, at least one non-coherent 8Tx precoder may include at least one of the following:

[0129] In some embodiments, the first set of antennas having 2 antennas may include antennas having {AP0, AP2}, and the second set of antennas having 2 antennas may include antennas having {AP4, AP6}, and the third set of antennas having 2 antennas may include antennas having {AP1, AP5}, and the fourth set of antennas having 2 antennas may include antennas having {AP3, AP7}. In some embodiments, at least one non-coherent 8Tx precoder may include at least one of the following: and In some embodiments, for a first set of antennas having 2 antennas or a first set of antennas having 2 antennas is configured or indicated, at least one non-coherent 8Tx precoder may include at least one of the following: In some embodiments, for a second set of antennas having 2 antennas or a second set of antennas having 2 antennas is configured or indicated, at least one non-coherent 8Tx precoder may include at least one of the following: In some embodiments, for a third set of antennas having 2 antennas or a third set of antennas having 2 antennas is configured or indicated, at least one partially coherent 8Tx precoder and / or at least one second partially coherent 8Tx precoder may include at least one of the following: In some embodiments, for a fourth set of antennas having 2 antennas or a fourth set of antennas having 2 antennas is configured or indicated, at least one non-coherent 8Tx precoder may include at least one of the following:

[0130] In some embodiments, s 4,1,5,1 may be a non-negative integer, and 0 ≤ s 4,1,5,1 ≤ St 1,5 - 1. In some embodiments, s 4,1,5,2 may be a non-negative integer, and 0 ≤ s4,1,5,2 ≤ St 1,5 -1. In some embodiments, s 4,1,5,3 can be a non - negative integer, and 0 ≤ s 4,1,5,3 ≤ St 1,5 -1. In some embodiments, s 4,1,5,4 can be a non - negative integer, and 0 ≤ s 4,1,5,4 ≤ St 1,5 -1.

[0131] In some embodiments, there can be a first set of vectors corresponding to 2 columns or rows, and the first set of vectors corresponding to 2 columns or rows can be applied to an 8Tx full - phase interference encoder with 2 or 5 layers and / or an 8Tx partial - phase interference encoder with 2 or 5 layers and / or an 8Tx first partial - phase interference encoder with 2 or 5 layers. In some embodiments, the first set of vectors corresponding to 2 columns or rows can be at least one of the following: and

[0132] In some embodiments, there can be a second set of vectors corresponding to 2 columns or rows, and the second set of vectors corresponding to 2 columns or rows can be applied to an 8Tx partial - phase interference encoder with 2 or 5 layers and / or an 8Tx first partial - phase interference encoder with 2 or 5 layers and / or an 8Tx second partial - phase interference encoder with 2 or 5 layers. In some embodiments, the second set of vectors corresponding to 2 columns or rows can be at least one of the following: and

[0133] In some embodiments, there can be a third set of vectors corresponding to 2 columns or rows, and the third set of vectors corresponding to 2 columns or rows can be applied to an 8Tx partial - phase interference encoder with 2 or 5 layers and / or an 8Tx non - interference encoder with 2 or 5 layers and / or an 8Tx second partial - phase interference encoder with 2 or 5 layers. In some embodiments, the third set of vectors corresponding to 2 columns or rows can be at least one of the following: and

[0134] In some embodiments, there may be a fourth set of vectors corresponding to 2 columns or rows, and the fourth set of vectors corresponding to 2 columns or rows may be applied to an 8Tx partial phase interference encoder with 2 or 5 layers and / or an 8Tx full phase interference encoder with 2 or 5 layers and / or an 8Tx second full phase interference encoder with 2 or 5 layers and / or an 8Tx second partial phase interference encoder with 2 or 5 layers and / or an 8Tx first partial phase interference encoder with 2 or 5 layers. In some embodiments, the third set of vectors corresponding to 2 columns or rows may be at least one of the following: and

[0135] In some embodiments, there may be a fifth set of vectors corresponding to 2 columns or rows, and the fifth set of vectors corresponding to 2 columns or rows may be applied to an 8Tx partial phase interference encoder with 2 or 5 layers and / or an 8Tx full phase interference encoder with 2 or 5 layers and / or an 8Tx second full phase interference encoder with 2 or 5 layers and / or an 8Tx second partial phase interference encoder with 2 or 5 layers and / or an 8Tx first partial phase interference encoder with 2 or 5 layers. In some embodiments, the third set of vectors corresponding to 2 columns or rows may be at least one of the following:

[0136] In some embodiments, for at least one of the full coherent and / or first full coherent and / or second full coherent and / or first partial coherent and / or second partial coherent and / or partial coherent and / or non-phase interference encoders for 2 or 5 layers, at least one of the first set of vectors corresponding to 2 columns or rows, the second set of vectors corresponding to 2 columns or rows, and the third set of vectors corresponding to 2 columns or rows may be substituted into embodiments for at least one of the following: the first set of vectors corresponding to 1 layer, the second set of vectors corresponding to 1 layer, the third set of vectors corresponding to 1 layer, the fourth set of vectors corresponding to 1 layer, and the fifth set of vectors corresponding to 1 layer. In some embodiments, each of at least one of the first set of vectors corresponding to 2 columns or rows, the second set of vectors corresponding to 2 columns or rows, and the third set of vectors corresponding to 2 columns or rows may be applied to 2 columns or 2 rows of a pre-encoder for 2 or 5 layers.

[0137] In some embodiments, there may be a first set of vectors corresponding to 3 columns or rows, and the first set of vectors corresponding to 3 columns or rows may be applied to an 8Tx full phase interference encoder with 3 or 6 or 5 or 7 layers and / or an 8Tx partial phase interference encoder with 3 or 6 or 5 or 7 layers and / or an 8Tx first partial phase interference encoder with 3 or 6 or 5 or 7 layers. In some embodiments, the first set of vectors corresponding to 3 columns or rows may be at least one of the following:

[0138] In some embodiments, there may be a second set of vectors corresponding to 3 columns or rows, and the second set of vectors corresponding to 3 columns or rows may be applied to an 8Tx partial interference encoder having 3 layers or 6 layers or 5 layers or 7 layers and / or an 8Tx first partial interference encoder having 3 layers or 6 layers or 5 layers or 7 layers and / or an 8Tx second partial interference encoder having 3 layers or 6 layers or 5 layers or 7 layers. In some embodiments, the second set of vectors corresponding to 3 columns or rows may be at least one of the following: and

[0139] In some embodiments, there may be a third set of vectors corresponding to 3 columns or rows, and the third set of vectors corresponding to 3 layers or 6 layers or 5 layers or 7 layers may be applied to an 8Tx partial interference encoder having 3 layers or 6 layers or 5 layers or 7 layers and / or an 8Tx non-interference encoder having 3 layers or 6 layers or 5 layers or 7 layers and / or an 8Tx second partial interference encoder having 3 layers or 6 layers or 5 layers or 7 layers. In some embodiments, the third set of vectors corresponding to 3 columns or rows may be at least one of the following:

[0140] In some embodiments, for at least one of the full coherent and / or first full coherent and / or second full coherent and / or first partial coherent and / or second partial coherent and / or partial coherent and / or non-interference encoders for 3 layers or 6 layers or 5 layers or 7 layers, at least one of the first set of vectors corresponding to 3 columns or 3 rows, the second set of vectors corresponding to 3 columns or 3 rows, and the third set of vectors corresponding to 3 columns or 3 rows may be substituted into the embodiments for at least one of the following: the first set of vectors corresponding to 1 layer, the second set of vectors corresponding to 1 layer, the third set of vectors corresponding to 1 layer, the fourth set of vectors corresponding to 1 layer, and the fifth set of vectors corresponding to 1 layer. In some embodiments, each of at least one of the first set of vectors corresponding to 3 columns or rows, the second set of vectors corresponding to 3 columns or rows, and the third set of vectors corresponding to 3 columns or rows may be applied to 3 columns or 3 rows of a pre-encoder for 3 layers or 6 layers or 5 layers or 7 layers.

[0141] In some embodiments, there may be a first set of vectors corresponding to 4 columns or rows, and the first set of vectors corresponding to 4 columns or rows may be applied to an 8Tx full interference encoder having 4 layers or 8 layers or 7 layers and / or an 8Tx partial interference encoder having 4 layers or 8 layers or 7 layers and / or an 8Tx first partial interference encoder having 4 layers or 8 layers or 7 layers. In some embodiments, the first set of vectors corresponding to 4 columns or rows may be at least one of the following:

[0142] In some embodiments, there may be a second set of vectors corresponding to 4 columns or rows, and the second set of vectors corresponding to 4 columns or rows may be applied to an 8Tx partial phase interference encoder having 4 layers or 7 layers or 8 layers and / or an 8Tx first partial phase interference encoder having 4 layers or 7 layers or 8 layers and / or an 8Tx second partial phase interference encoder having 4 layers or 7 layers or 8 layers. In some embodiments, the second set of vectors corresponding to 4 columns or rows may be at least one of the following: and

[0143] In some embodiments, there may be a third set of vectors corresponding to 4 columns or rows, and the third set of vectors corresponding to 4 columns or rows may be applied to an 8Tx partial phase interference encoder having 4 layers or 7 layers or 8 layers and / or an 8Tx non-phase interference encoder having 4 layers or 7 layers or 8 layers and / or an 8Tx second partial phase interference encoder having 4 layers or 7 layers or 8 layers. In some embodiments, the third set of vectors corresponding to 4 columns or rows may be at least one of the following:

[0144] In some embodiments, for at least one of the full coherent and / or first full coherent and / or second full coherent and / or first partial coherent and / or second partial coherent and / or partial coherent and / or non-phase interference encoders for 4 layers or 7 layers or 8 layers, at least one of the first set of vectors corresponding to 4 columns or 4 rows, the second set of vectors corresponding to 4 columns or 4 rows, and the third set of vectors corresponding to 4 columns or 4 rows may be substituted into the embodiments for at least one of the following: the first set of vectors corresponding to 1 layer, the second set of vectors corresponding to 1 layer, the third set of vectors corresponding to 1 layer, the fourth set of vectors corresponding to 1 layer, and the fifth set of vectors corresponding to 1 layer. In some embodiments, each of at least one of the first set of vectors corresponding to 4 columns or rows, the second set of vectors corresponding to 4 columns or rows, and the third set of vectors corresponding to 4 columns or rows may be applied to 4 columns or 4 rows of a pre-encoder for 4 layers or 7 layers or 8 layers.

[0145] In some embodiments, for a pre-encoder for 5 layers, 2 columns or rows of the pre-encoder may include the first set of vectors and / or the second set of vectors and / or the third set of vectors and / or the fourth set of vectors and / or the fifth set of vectors corresponding to 2 columns or rows, and the other 3 columns or rows of the pre-encoder may include the first set of vectors and / or the second set of vectors and / or the third set of vectors corresponding to 3 columns or rows.

[0146] In some embodiments, for a pre-encoder for 5 layers, 1 column or row of the pre-encoder may include the first set of vectors and / or the second set of vectors and / or the third set of vectors and / or the fourth set of vectors and / or the fifth set of vectors corresponding to 1 layer, and the other 4 columns or rows of the pre-encoder may include the first set of vectors and / or the second set of vectors and / or the third set of vectors corresponding to 4 columns or rows.

[0147] In some embodiments, for a precoder for six layers, two columns or rows of the precoder may include a first set of vectors and / or a second set of vectors and / or a third set of vectors and / or a fourth set of vectors and / or a fifth set of vectors corresponding to the two columns or rows, and the other four columns or rows of the precoder may include a first set of vectors and / or a second set of vectors and / or a third set of vectors corresponding to the four columns or rows.

[0148] In some embodiments, for a precoder for six layers, one column or row of the precoder may include a first set of vectors and / or a second set of vectors and / or a third set of vectors and / or a fourth set of vectors and / or a fifth set of vectors corresponding to one layer, and the other four columns or rows of the precoder may include a first set of vectors and / or a second set of vectors and / or a third set of vectors corresponding to the four columns or rows.

[0149] In some embodiments, for a precoder for six layers, three columns or rows of the precoder may include a first set of vectors and / or a second set of vectors and / or a third set of vectors and / or a fourth set of vectors and / or a fifth set of vectors corresponding to the three columns or rows, and the other three columns or rows of the precoder may include a first set of vectors and / or a second set of vectors and / or a third set of vectors corresponding to the three columns or rows.

[0150] In some embodiments, for a precoder for seven layers, three columns or rows of the precoder may include a first set of vectors and / or a second set of vectors and / or a third set of vectors and / or a fourth set of vectors and / or a fifth set of vectors corresponding to the three columns or rows, and the other four columns or rows of the precoder may include a first set of vectors and / or a second set of vectors and / or a third set of vectors corresponding to the four columns or rows.

[0151] In some embodiments, for a precoder for eight layers, four columns or rows of the precoder may include a first set of vectors and / or a second set of vectors and / or a third set of vectors and / or a fourth set of vectors and / or a fifth set of vectors corresponding to the four columns or rows, and the other four columns or rows of the precoder may include a first set of vectors and / or a second set of vectors and / or a third set of vectors corresponding to the four columns or rows.

[0152] In some embodiments, for example, for a first full-phase precoder may be

[0153] In some embodiments, for example, for a first full-phase precoder may be

[0154] In some embodiments, P can be 8 or 12 or 16. In some embodiments, l can be a non-negative integer. For example, 0 ≤ l ≤ O1N1. For another example, 0 ≤ l ≤ O1N1 / 2. For another example, l can be at least one of {0, 2, 4, 6}. For another example, l can be at least one of {0, 1, 2, 3}. For another example, l can be 0 or 1. For another example, l can be 0 or 2. In some embodiments, m can be a non-negative integer. For example, 0 ≤ m ≤ O2N2. For another example, m can be at least one of {0, 2, 4, 6}. For another example, m can be at least one of {0, 1, 2, 3}. For another example, m can be 0 or 1. For another example, m can be 0 or 2. For another example, m can be 0. In some embodiments, n can be a non-negative integer. For example, n can be at least one of {0, 1, 2, 3}. For another example, n can be 0 or 1. For another example, n can be 0 or 2. For another example, n can be 0. In some embodiments, l′ = l + O1. In some embodiments, l″ = l + 2O1. In some embodiments, l″′ = l + 3O1. In some embodiments, m and m′ and m″ and m″′ can be 0. In some embodiments, l′ = l + O1. In some embodiments, l″ = l. In some embodiments, l″′ = l + O1. In some embodiments, m′ = m. In some embodiments, m″ = m + O2. In some embodiments, m″′ = m + O2.

[0155] In some embodiments, there can be more than one subset of precoding matrices corresponding to 8 layers. In some embodiments, the first set of precoding matrices corresponding to 8 layers can include more than one subset. For example, there can be two subsets of precoding matrices.

[0156] In some embodiments, there can be a first subset of precoding matrices corresponding to 8 layers, and corresponding to the first subset of precoding matrices, the value of “N1” can be 4, the value of “N2” can be 1, and the value of “O1” can be 4 or 2 or 1. For example, the value of “O2” can be 1. In some embodiments, corresponding to the first subset, In some embodiments, corresponding to the first subset, m and m′ and m″ and m″′ can be 0. In some embodiments, corresponding to the first subset, l′ = l + O1, l″ = l + 2O1 and l″′ = l + 3O1. In some embodiments, corresponding to the first subset, l can be a non-negative integer, 0 ≤ l ≤ O1N1. For example, l can be at least one of {0, 2, 4, 6}. For another example, l can be at least one of {0, 1, 2, 3}. For another example, l can be 0 or 1. For another example, l can be 0 or 2. In some embodiments, the number of precoding matrices in the first subset corresponding to 8 layers can be 32 or 16 or 8 or 4 or 2.

[0157] In some embodiments, there may be a second subset of precoding matrices corresponding to 8 layers, and corresponding to the second subset of precoding matrices, the value of "N1" may be 2, the value of "N2" may be 2, and the value of "O1" may be 4 or 2 or 1. For example, the value of "O2" may be 4 or 2 or 1. In some embodiments, corresponding to the second subset, In some embodiments, corresponding to the second subset, l′ = l + O1, l″ = l and l″′ = l + O1. In some embodiments, corresponding to the second subset, m′ = m, m″ = m + O2 and m″′ = m + O2. In some embodiments, corresponding to the second subset, l may be a non - negative integer, 0 ≤ l ≤ O1N1. For example, l may be at least one of {0, 2, 4, 6}. Again, for example, l may be at least one of {0, 1, 2, 3}. Again, for example, l may be 0 or 1. Again, for example, l may be 0 or 2. In some embodiments, corresponding to the second subset, m may be a non - negative integer. For example, 0 ≤ m ≤ O2N2. Again, for example, m may be at least one of {0, 2, 4, 6, 8}. Again, for example, m may be at least one of {0, 1, 2, 3}. Again, for example, m may be 0 or 1. Again, for example, m may be 0. In some embodiments, the number of precoding matrices in the second subset corresponding to 8 layers may be 128 or 32 or 16 or 8 or 4 or 2.

[0158] In some embodiments, the parameter "N1" represents the number of ports in the first dimension. The parameter "N2" represents the number of ports in the second dimension. The parameter "O1" represents the first discrete Fourier transform (DFT) oversampling in the first dimension, and the parameter "O2" represents the second DFT oversampling in the second dimension. The parameter "i" represents an element in the precoding matrix.

[0159] In some embodiments, N1 may be equal to 4, N2 equal to 1, O1 may be equal to 2, and O2 may be equal to 1, and i 1,1 may be one of the following: {0, … N1O1 - 1} or {0, 2, 4, 6} or {0, 4} or {0, 1} or 0 or {0, … N1O1 / 2 - 1} or {0, 2}. In some embodiments, the first subset "Set_f8_1" of full - phase precoding matrices corresponding to 8 layers may include 16 precoding matrices. In some embodiments, the precoding matrix subset "Set_f8_1" may include 8 precoding matrices. Alternatively, the precoding matrix subset "Set_f8_1" may include 4 precoding matrices. In other embodiments, the precoding matrix subset "Set_f8_1" may include 2 precoding matrices.

[0160] Alternatively, N1 may be equal to 2, N2 equal to 2, O1 may be equal to 1 or 4, and O2 may be equal to 2 or 4, i 1,1or i 1,2 may be one of the following: {0, … 7} or {0, 2, 4, 6} or {0, 4} or {0, … 3} or {0, 2} or {0, 1} or 0. In some embodiments, the second subset “Set_f8_2” of the full-phase interference coding matrix corresponding to 8 layers may include 128 precoding matrices. In some embodiments, the subset of precoding matrices “Set_f8_2” may include 32 precoding matrices. Alternatively, the subset of precoding matrices “Set_f8_2” may include 8 precoding matrices. In other embodiments, the subset of precoding matrices “Set_f8_2” may include 2 precoding matrices.

[0161] In some embodiments, if the terminal device 110 is indicated to have 8 layers, there may be a second set of precoding matrices corresponding to 8 layers (e.g., the second set of partial interference precoding matrices). For example, if the terminal device 110 has 8 antenna ports, or if the PUSCH transmission of the terminal device 110 is associated with 8 antenna ports, or if the PUSCH transmission of the terminal device 110 is associated with an SRS having 8 ports, then 4 antenna ports (e.g., the first set of 4 ports) may be coherent, and the other 4 antenna ports (e.g., the second set of 4 ports) may be coherent. For example, the first set of 4 ports may be non - coherent with the second set of 4 ports. In some embodiments, there may be a second set of precoding matrices corresponding to 8 layers (e.g., the second set of partial interference precoding matrices), such as denoted as "Set_p8_1", and the size of the partial interference precoding matrix may be 8 by 8. In some embodiments, the precoding matrix may have 8 columns or rows. In some embodiments, there may be 8 elements in a column or row of the precoding matrix. In some embodiments, for a column or row of the partial interference precoding matrix, 4 of the 8 elements in the partial interference precoding matrix may have non - zero values. And the other 4 elements in the partial interference precoding matrix may have a value of 0. In some embodiments, there may be 4 columns or rows (e.g., the first set of 4 columns or rows) out of 8 columns or rows in the precoding matrix, and in each column or row, the non - zero values may be mapped to 4 of the 8 elements, and 0 may be mapped to the other 4 elements. For example, the indices of the 4 elements with non - zero values may be the same in the first set of 4 columns or rows. For example, the indices of the 4 elements with non - zero values may be idx_1, and idx_1 may be 4 values from {0, 1, 2, 3, 4, 5, 6, 7} or {1, 2, 3, 4, 5, 6, 7, 8}. For example, idx_1 may be {0, 1, 2, 3} or {0, 2, 4, 6} or {1, 2, 3, 4} or {1, 3, 5, 7}. In some embodiments, the 4 values of idx_1 may be based on the indices of the antenna ports in the first set having 4 antenna ports. In some embodiments, for the other 4 columns or rows (e.g., the second set of 4 columns or rows) out of 8 columns or rows in the precoding matrix, in each column or row, the non - zero values may be mapped to 4 of the 8 elements, and 0 may be mapped to the other 4 elements. For example, the indices of the 4 elements with non - zero values may be the same in the second set of 4 columns or rows. For example, the indices of the 4 elements with non - zero values may be idx_2, and idx_2 may be 4 values from {0, 1, 2, 3, 4, 5, 6, 7} or {1, 2, 3, 4, 5, 6, 7, 8}. For example, idx_2 may be {4, 5, 6, 7} or {1, 3, 5, 7} or {5, 6, 7, 8} or {2, 4, 6, 8}.In some embodiments, the four values of idx_2 may be based on the indices of the antenna ports in a second group having four antenna ports. In some embodiments, any value of idx_1 may be different from any value of idx_2.

[0162] In some embodiments, there may be two sets of vectors of length four, and each set may include four vectors of length four. In some embodiments, the values in the vectors of length four may be applied to four non-zero values that map to four elements in a column or a row of a precoding matrix. For example, the first set of vectors of length four may be {[1; 1; 1; 1], [1; -1; 1; -1], [1; 1; -1; -1], [1; -1; -1; 1]}. As another example, the second set of vectors of length four may be {[1; 1; j; j], [1; -1; j; -j], [1; 1; -j; -j], [1; -1; -j; j]}. In some embodiments, the four values in each vector of the first set or the second set may be mapped to four elements out of eight elements, and 0 may be mapped to the other four elements in a column or a row of the precoding matrix. In some embodiments, a set of precoding matrices "Set_p8_1" may include 280 precoding matrices, i.e., C(2,1)*C(2,1)*C(8,4). In some embodiments, C(x, y) may represent permutations and combinations. For example, C(x, y) may represent the number of possible schemes of selecting y values from x values. For example, rows or columns can be swapped. For example, each of [a1, a2, a3, a4], [b1, b2, b3, b4], [c1, c2, c3, c4], and [d1, d2, d3, d4] can be one of the vectors of length 4 in the first group of vectors of length 4 or the second group of vectors of length 4. For example, each of [e1, e2, e3, e4], [f1, f2, f3, f4], [g1, g2, g3, g4], and [h1, h2, h3, h4] can be one of the vectors of length 4 in the first group of vectors of length 4 or the second group of vectors of length 4. For example, [a1, a2, a3, a4], [b1, b2, b3, b4], [c1, c2, c3, c4], and [d1, d2, d3, d4] can be [1; 1; 1; 1], [1; -1; 1; -1], [1; 1; -1; -1], and [1; -1; -1; 1] respectively. Again, for example, [a1, a2, a3, a4], [b1, b2, b3, b4], [c1, c2, c3, c4], and [d1, d2, d3, d4] can be [1; 1; j; j], [1; -1; j; -j], [1; 1; -j; -j], and [1; -1; -j; j] respectively. For example, [e1, e2, e3, e4], [f1, f2, f3, f4], [g1, g2, g3, g4], and [h1, h2, h3, h4] can be [1; 1; 1; 1], [1; -1; 1; -1], [1; 1; -1; -1], and [1; -1; -1; 1] respectively. Again, for example, [e1, e2, e3, e4], [f1, f2, f3, f4], [g1, g2, g3, g4], and [h1, h2, h3, h4] can be [1; 1; j; j], [1; -1; j; -j], [1; 1; -j; -j], and [1; -1; -j; j] respectively.

[0163] In some embodiments, s8 can be a positive integer. For example, 1 ≤ s8 ≤ 64. For example, s8 can be 64 or 32 or 16 or 8 or 4 or 2.

[0164] In some embodiments, if the terminal device 110 is indicated to have 8 layers, there may be a third set of precoding matrices (e.g., a third set of partial interference precoding matrices) corresponding to 8 layers. For example, the structure of 8 ports may be 2+2+2+2, which means there are 4 groups, each group including 2 antenna ports, and within each group, the 2 antenna ports may be coherent. For example, between groups, the antenna ports may not be coherent. In some embodiments, there may be a third set of precoding matrices (e.g., a third set of partial interference precoding matrices) corresponding to 8 layers, such as denoted as "Set_p8_2", and the size of the precoding matrix may be 8 by 8. In some embodiments, the precoding matrix may have 8 columns or rows. In some embodiments, there may be 8 elements in a column or row of the precoding matrix. In some embodiments, for a column or row of the precoding matrix, 2 of the 8 elements in the precoding matrix may have non-zero values. And the other 6 elements in the precoding matrix may have a value of 0. In some embodiments, there may be 2 columns or rows (e.g., a first set of 2 columns or rows) out of 8 columns or rows in the precoding matrix, and in each column or row, the non-zero values may be mapped to 2 of the 8 elements, and 0 may be mapped to the other 6 elements. For example, in the first set of 2 columns or rows, the indices of the 2 elements with non-zero values may be the same. For example, the indices of the 2 elements with non-zero values may be idx_1, and idx_1 may be 2 values from {0,1,2,3,4,5,6,7} or {1,2,3,4,5,6,7,8}. In some embodiments, the 2 values of idx_1 may be based on the indices of two antenna ports out of the 4 antenna ports in the first group. In some embodiments, the 2 values of idx_1 may be based on the indices of 2 antenna ports in the third group. For example, idx_1 may be {0,1} or {0,2} or {1,2} or {1,3} or {0,4} or {1,5}. In some embodiments, there may be 2 columns or rows (e.g., a second set of 2 columns or rows) out of 8 columns or rows in the precoding matrix, and in each column or row, the non-zero values may be mapped to 2 of the 8 elements, and 0 may be mapped to the other 6 elements. For example, in the second set of 2 columns or rows, the indices of the 2 elements with non-zero values may be the same. For example, the indices of the 2 elements with non-zero values may be idx_2, and idx_2 may be 2 values from {0,1,2,3,4,5,6,7} or {1,2,3,4,5,6,7,8}. In some embodiments, the 2 values of idx_2 may be based on the indices of the other two antenna ports out of the 4 antenna ports in the first group. In some embodiments, the 2 values of idx_2 may be based on the indices of 2 antenna ports in the fourth group. For example, idx_2 may be {2,3} or {1,3} or {3,4} or {2,4} or {1,5} or {2,6}.In some embodiments, there may be 2 columns or rows out of 8 columns or rows in a precoding matrix (e.g., the third group of 2 columns or rows), and in each column or row, non-zero values may be mapped to 2 elements out of 8 elements, and 0 may be mapped to the other 6 elements. For example, in the third group of 2 columns or rows, the indices of the 2 elements with non-zero values may be the same. For example, the indices of the 2 elements with non-zero values may be idx_3, and idx_3 may be 2 values from {0, 1, 2, 3, 4, 5, 6, 7} or {1, 2, 3, 4, 5, 6, 7, 8}. In some embodiments, the 2 values of idx_3 may be based on the indices of two antenna ports out of the 4 antenna ports in the second group. In some embodiments, the 2 values of idx_3 may be based on the indices of 2 antenna ports in the fifth group. For example, idx_3 may be {4, 5} or {4, 6} or {5, 6} or {5, 7} or {2, 6} or {3, 7}. In some embodiments, there may be 2 columns or rows out of 8 columns or rows in a precoding matrix (e.g., the fourth group of 2 columns or rows), and in each column or row, non-zero values may be mapped to 2 elements out of 8 elements, and 0 may be mapped to the other 6 elements. For example, in the fourth group of 2 columns or rows, the indices of the 2 elements with non-zero values may be the same. For example, the indices of the 2 elements with non-zero values may be idx_4, and idx_4 may be 2 values from {0, 1, 2, 3, 4, 5, 6, 7} or {1, 2, 3, 4, 5, 6, 7, 8}. In some embodiments, the 2 values of idx_4 may be based on the indices of the other two antenna ports out of the 4 antenna ports in the first group. In some embodiments, the 2 values of idx_4 may be based on the indices of 2 antenna ports in the sixth group. For example, idx_4 may be {6, 7} or {5, 7} or {7, 8} or {6, 8} or {3, 7} or {4, 8}. In some embodiments, any value of idx_1, any value of idx_2, any value of idx_3, and any value of idx_4 may be different from each other.

[0165] In some embodiments, there can be a set of 4 vectors of length 2, and each of the vectors of length 2 can be applied as two non-zero values in a column or a row of a precoding matrix. In some embodiments, for the third set of precoding matrices Set_p8_2, two vectors of length 2 can be selected from the 4 vectors of length 2, and the 2 values in each vector can be mapped to 2 of the 8 elements, and 0 can be mapped to the other elements in a column or a row of the precoding matrix. In some embodiments, there can be two sets of vectors of length 2, and each set can include 2 vectors of length 2. In some embodiments, the two values in a vector of length 2 can be applied as two non-zero values mapped to 2 elements in a column or a row of a precoding matrix. For example, the first set of vectors of length 2 can be {[1; 1], [1; -1]}. For another example, the second set of vectors of length 2 can be {[1; j], [1; -j]}. In some embodiments, the 2 values in each vector in the first set or the second set can be mapped to 2 of the 8 elements, and 0 can be mapped to the other 6 elements in a column or a row of the precoding matrix.

[0166] For example, rows or columns can be swapped. For example, each of [a1, a2], [b1, b2] can be one of the vectors of length 2 in the first set of vectors of length 2 or the second set of vectors of length 2. For example, each of [c1, c2] and [d1, d2] can be one of the vectors of length 2 in the first set of vectors of length 2 or the second set of vectors of length 2. For example, each of [e1, e2], [f1, f2] can be one of the vectors of length 2 in the first set of vectors of length 2 or the second set of vectors of length 2. For example, each of [g1, g2] and [h1, h2] can be one of the vectors of length 2 in the first set of vectors of length 2 or the second set of vectors of length 2. For example, [a1, a2], [b1, b2] can be [1; 1], [1; -1] respectively. For another example, [a1, a2], [b1, b2] can be [1; j], [1; -j] respectively. For example, [c1, c2] and [d1, d2] can be [1; 1], [1; -1] respectively. For another example, [c1, c2] and [d1, d2] can be [1; j], [1; -j] respectively. For example, [e1, e2], [f1, f2] can be [1; 1], [1; -1] respectively. For another example, [e1, e2], [f1, f2] can be [1; j], [1; -j] respectively. For example, [g1, g2] and [h1, h2] can be [1; 1], [1; -1] respectively. For another example, [g1, g2] and [h1, h2] can be [1; j], [1; -j] respectively.

[0167] In some embodiments, if the terminal device 110 is indicated to have 8 layers, there may be a fourth set of precoding matrices corresponding to 8 layers (e.g., a fourth set of non-coherent precoding matrices). For example, each of the 8 antenna ports may be non-coherent with each other. In some embodiments, there may be a fourth set of precoding matrices corresponding to 8 layers (e.g., a fourth set of non-coherent precoding matrices), such as denoted as "Set_n8_1", and the size of the precoding matrix may be 8 by 8. In some embodiments, the precoding matrix may have 8 columns or rows. In some embodiments, there may be 8 elements in a column or row of the precoding matrix. In some embodiments, for a column or row of the precoding matrix, 1 element out of the 8 elements in the precoding matrix may have a non-zero value. For example, the non-zero value may be 1. And the other 7 elements in the precoding matrix may have a value of 0. In some embodiments, for each of the 8 columns or rows in the precoding matrix, the non-zero value may be mapped to 1 element out of the 8 elements, and 0 may be mapped to the other 7 elements. For example, in each row or column of the precoding matrix, the index of the element with the non-zero value may be different. For example, the indices of the 1 element with the non-zero value may be idx_1, idx_2, idx_3, idx_4, idx_5, idx_6, idx_7, idx_8 for the first, second, third, fourth, fifth, sixth, seventh, eighth columns or rows of the precoding matrix respectively, and for each of idx_1, idx_2, idx_3, idx_4, idx_5, idx_6, idx_7, idx_8, the value may be one value from {0, 1, 2, 3, 4, 5, 6, 7} or {1, 2, 3, 4, 5, 6, 7, 8}. For example, the values of idx_1, idx_2, idx_3, idx_4, idx_5, idx_6, idx_7, idx_8 may be 0, 1, 2, 3, 4, 5, 6, 7 respectively. As another example, the values of idx_1, idx_2, idx_3, idx_4, idx_5, idx_6, idx_7, idx_8 may be 1, 2, 3, 4, 5, 6, 7, 8 respectively. In some embodiments, the values of idx_1, idx_2, idx_3, idx_4, idx_5, idx_6, idx_7, idx_8 may be different from each other.

[0168] In some embodiments, if the terminal device 110 is indicated to have a layer number indicated as 8, there may be a fourth set of precoding matrices corresponding to 8 layers. For example, there may be only one precoding matrix (e.g., a non-coherent precoding matrix) in the fourth set corresponding to 8 layers.

[0169] In some embodiments, if the terminal device 110 is indicated to have 8 layers, there may be a fifth set of precoding matrices (e.g., hybrid partial interference precoding matrices) corresponding to 8 layers. For example, the structure of 8 ports can be 4 + 2 + 2, which means that 4 antenna ports can be coherent, 2 antenna ports can be coherent, and the other 2 antenna ports can be coherent. In some embodiments, there may be a fifth set of precoding matrices (e.g., hybrid partial interference precoding matrices) corresponding to 8 layers, such as denoted as "Set_p8_3", and the size of the partial interference precoding matrix can be 8 by 8. In some embodiments, the precoding matrix can have 8 columns or rows. In some embodiments, there can be 8 elements in a column or row of the precoding matrix. In some embodiments, there may be 4 columns or rows out of 8 columns or rows in the precoding matrix (e.g., the first set of 4 columns or rows), and in each column or row, non-zero values can be mapped to 4 elements out of 8 elements, and 0 can be mapped to the other 4 elements. For example, in the first set of 4 columns or rows, the indices of the 4 elements with non-zero values can be the same. For example, the indices of the 4 elements with non-zero values can be idx_1, and idx_1 can be 4 values out of {0, 1, 2, 3, 4, 5, 6, 7} or {1, 2, 3, 4, 5, 6, 7, 8}. For example, idx_1 can be {0, 1, 2, 3} or {0, 2, 4, 6} or {1, 2, 3, 4} or {1, 3, 5, 7}. In some embodiments, there may be 2 columns or rows out of 8 columns or rows in the precoding matrix (e.g., the second set of 2 columns or rows), and in each column or row, non-zero values can be mapped to 2 elements out of 8 elements, and 0 can be mapped to the other 6 elements. For example, in the second set of 2 columns or rows, the indices of the 2 elements with non-zero values can be the same. For example, the indices of the 2 elements with non-zero values can be idx_2, and idx_2 can be 2 values out of {0, 1, 2, 3, 4, 5, 6, 7} or {1, 2, 3, 4, 5, 6, 7, 8}. For example, idx_2 can be {4, 5} or {1, 3} or {5, 6} or {2, 4}. In some embodiments, there may be 2 columns or rows out of 8 columns or rows in the precoding matrix (e.g., the third set of 2 columns or rows), and in each column or row, non-zero values can be mapped to 2 elements out of 8 elements, and 0 can be mapped to the other 6 elements. For example, in the third set of 2 columns or rows, the indices of the 2 elements with non-zero values can be the same. For example, the indices of the 2 elements with non-zero values can be idx_3, and idx_3 can be 2 values out of {0, 1, 2, 3, 4, 5, 6, 7} or {1, 2, 3, 4, 5, 6, 7, 8}. For example, idx_3 can be {6, 7} or {5, 7} or {7, 8} or {6, 8}. In some embodiments, any value of idx_1, any value of idx_2, and any value of idx_3 can be different from each other.In some embodiments, the values in the vectors of the first group of length 4 or the second group of length 4 can be applied to the 4 non-zero values among the 4 elements in the columns or rows mapped to the first group of 4 columns or rows of the precoding matrix. For example, the first group of vectors of length 4 can be {[1; 1; 1; 1], [1; -1; 1; -1], [1; 1; -1; -1], [1; -1; -1; 1]}. Another example, the second group of vectors of length 4 can be {[1; 1; j; j], [1; -1; j; -j], [1; 1; -j; -j], [1; -1; -j; j]}. In some embodiments, the 4 values in each vector in the first group or the second group can be mapped to 4 of the 8 elements, and 0 can be mapped to the other 4 elements in the columns or rows of the precoding matrix. In some embodiments, the two values in the vectors of length 2 in the first group of vectors of length 2 or the second group of vectors of length 2 can be applied as the two non-zero values mapped to the 2 elements in the columns or rows of the second group of 2 columns or rows of the precoding matrix. In some embodiments, the two values in the vectors of length 2 in the first group of vectors of length 2 or the second group of vectors of length 2 can be applied as the two non-zero values mapped to the 2 elements in the columns or rows of the third group of 2 columns or rows of the precoding matrix. For example, the first group of vectors of length 2 can be {[1; 1], [1; -1]}. Another example, the second group of vectors of length 2 can be {[1; j], [1; -j]}. In some embodiments, the 2 values in each vector in the first group or the second group can be mapped to 2 of the 8 elements, and 0 can be mapped to the other 6 elements in the columns or rows of the precoding matrix.

[0170] In some embodiments, 4 of the 8 columns can be mapped with vectors of length 4, and for 2 of the remaining 4 columns, each column can be mapped with a vector of length 2, and for the remaining 3 columns, each column can be mapped with a vector of length 2.

[0171] For example, rows or columns can be swapped. For example, each of [a1, a2, a3, a4], [b1, b2, b3, b4], [c1, c2, c3, c4], and [d1, d2, d3, d4] can be one of the vectors of length 4 in the first group of vectors of length 4 or the second group of vectors of length 4. For example, [a1, a2, a3, a4], [b1, b2, b3, b4], [c1, c2, c3, c4], and [d1, d2, d3, d4] can be [1; 1; 1; 1], [1; -1; 1; -1], [1; 1; -1; -1], and [1; -1; -1; 1], respectively. As another example, [a1, a2, a3, a4], [b1, b2, b3, b4], [c1, c2, c3, c4], and [d1, d2, d3, d4] can be [1; 1; j; j], [1; -1; j; -j], [1; 1; -j; -j], and [1; -1; -j; j], respectively. For example, [e1, e2] and [f1, f2] can be [1; 1] and [1; -1], respectively. As another example, [e1, e2] and [f1, f2] can be [1; j] and [1; -j], respectively. For example, [g1, g2] and [h1, h2] can be [1; 1] and [1; -1], respectively. As another example, [g1, g2] and [h1, h2] can be [1; j] and [1; -j], respectively.

[0172] In other embodiments, if the terminal device 110 is indicated to have 8 layers, there may be a sixth set of precoding matrices corresponding to 8 layers (e.g., a mixed partial and non-interfering precoding matrix). For example, the structure of 8 antenna ports can be 4 + 1 + 1 + 1 + 1, which means that 4 antenna ports can be coherent and the remaining 4 antenna ports can be non-coherent. For example, rows or columns can be swapped. For example, each of [a1, a2, a3, a4], [b1, b2, b3, b4], [c1, c2, c3, c4], and [d1, d2, d3, d4] can be one of the vectors of length 4 in the first group of vectors of length 4 or the second group of vectors of length 4. For example, [a1, a2, a3, a4], [b1, b2, b3, b4], [c1, c2, c3, c4], and [d1, d2, d3, d4] can be [1; 1; 1; 1], [1; -1; 1; -1], [1; 1; -1; -1], and [1; -1; -1; 1], respectively. As another example, [a1, a2, a3, a4], [b1, b2, b3, b4], [c1, c2, c3, c4], and [d1, d2, d3, d4] can be [1; 1; j; j], [1; -1; j; -j], [1; 1; -j; -j], and [1; -1; -j; j], respectively.

[0173] In some embodiments, if the terminal device 110 is indicated to have 8 layers, there may be a seventh set of precoding matrices corresponding to 8 layers (e.g., a mixed partial and non-interfering precoding matrix). For example, the structure of 8 ports can be 4 + 2 + 1 + 1, which means that 4 antenna ports can be coherent and 2 antenna ports can be coherent. For example, rows or columns can be swapped. For example, each of [a1, a2, a3, a4], [b1, b2, b3, b4], [c1, c2, c3, c4], and [d1, d2, d3, d4] can be one of the vectors of length 4 in the first set of vectors of length 4 or the second set of vectors of length 4. For example, [a1, a2, a3, a4], [b1, b2, b3, b4], [c1, c2, c3, c4], and [d1, d2, d3, d4] can be [1; 1; 1; 1], [1; -1; 1; -1], [1; 1; -1; -1], and [1; -1; -1; 1], respectively. Again, for example, [a1, a2, a3, a4], [b1, b2, b3, b4], [c1, c2, c3, c4], and [d1, d2, d3, d4] can be [1; 1; j; j], [1; -1; j; -j], [1; 1; -j; -j], and [1; -1; -j; j], respectively. For example, [e1, e2], [f1, f2] can be [1; 1], [1; -1], respectively. Again, for example, [e1, e2], [f1, f2] can be [1; j], [1; -j], respectively.

[0174] In other embodiments, if the terminal device 110 is indicated to have 8 layers, there may be an eighth set of precoding matrices corresponding to 8 layers (e.g., a mixed partial and non-interfering precoding matrix). For example, the structure of 8 ports can be 2 + 2 + 1 + 1 + 1 + 1, which means that 2 antenna ports can be coherent and 2 antenna ports can be coherent. In other embodiments, the antenna structure can be 2 + 1 + 1 + 1 + 1 + 1 + 1. Alternatively, the antenna structure can be 2 + 2 + 2 + 1 + 1. For example, [a1, a2], [b1, b2] can be [1; 1], [1; -1], respectively. Again, for example, [a1, a2], [b1, b2] can be [1; j], [1; -j], respectively. For example, [c1, c2] and [d1, d2] can be [1; 1], [1; -1], respectively. Again, for example, [c1, c2] and [d1, d2] can be [1; j], [1; -j], respectively.

[0175] In some embodiments, when the terminal device 110 is indicated to have 7 layers, there may be a first set of precoding matrices corresponding to 7 layers (e.g., the first set of fully coherent precoding matrices), and the fully coherent precoding matrix can be expressed as:

[0176] In some embodiments, may be

[0177] In some embodiments, may be

[0178] In some embodiments, P may be 8 or 12 or 16. In some embodiments, l may be a non - negative integer. For example, 0 ≤ l ≤ O1N1. Also for example, 0 ≤ l ≤ O1N1 / 2. Also for example, l may be at least one of {0, 2, 4, 6, 8}. Also for example, l may be at least one of {0, 1, 2, 3}. Also for example, l may be 0 or 1. In some embodiments, m may be a non - negative integer. For example, 0 ≤ m ≤ O2N2. Also for example, m may be at least one of {0, 2, 4, 6, 8}. Also for example, m may be at least one of {0, 1, 2, 3}. Also for example, m may be 0 or 1. Also for example, m may be 0. In some embodiments, n may be a non - negative integer. For example, n may be at least one of {0, 1, 2, 3}. Also for example, n may be 0 or 1. Also for example, n may be 0 or 2. Also for example, n may be 0. In some embodiments, l′ = l + O1. In some embodiments, l″ = l + 2O1. In some embodiments, l″′ = l + 3O1. In some embodiments, m and m′ and m″ and m″′ may be 0. In some embodiments, l′ = l + O1. In some embodiments, l″ = l. In some embodiments, l″′ = l + O1. In some embodiments, m′ = m. In some embodiments, m″ = m + O2. In some embodiments, m″′ = m + O2.

[0179] In some embodiments, there may be more than one subset of precoding matrices corresponding to 7 layers. In some embodiments, the first set of precoding matrices corresponding to 7 layers may include more than one subset. For example, there may be two subsets of precoding matrices.

[0180] In some embodiments, there may be a first subset of precoding matrices corresponding to 7 layers, and for the first subset of precoding matrices, the value of "N1" may be 4, the value of "N2" may be 1, and the value of "O1" may be 4 or 2 or 1. For example, the value of "O2" may be 1. In some embodiments, for the first subset, In some embodiments, corresponding to the first subset, m, m′, m″, and m″′ can be 0. In some embodiments, corresponding to the first subset, l′ = l + O1, l″ = l + 2O1, and l″′ = l + 3O1. In some embodiments, corresponding to the first subset, l can be a non-negative integer, 0 ≤ l ≤ O1N1. For example, l can be at least one of {0, 2, 4, 6}. For another example, l can be at least one of {0, 1, 2, 3}. For another example, l can be 0 or 1. For another example, l can be 0 or 2. In some embodiments, the number of precoding matrices in the first subset corresponding to 7 layers can be 32 or 16 or 8 or 4 or 2.

[0181] In some embodiments, there can be a second subset of precoding matrices corresponding to 7 layers, and corresponding to the second subset of precoding matrices, the value of "N1" can be 2, the value of "N2" can be 2, and the value of "O1" can be 4 or 2 or 1. For example, the value of "O2" can be 4 or 2 or 1. In some embodiments, corresponding to the second subset, In some embodiments, corresponding to the second subset, l′ = l + O1, l″ = l, and l″′ = l + O1. In some embodiments, corresponding to the second subset, m′ = m, m″ = m + O2, and m″′ = m + O2. In some embodiments, corresponding to the second subset, l can be a non-negative integer, 0 ≤ l ≤ O1N1. For example, l can be at least one of {0, 2, 4, 6}. For another example, l can be at least one of {0, 1, 2, 3}. For another example, l can be 0 or 1. For another example, l can be 0 or 2. In some embodiments, corresponding to the second subset, m can be a non-negative integer. For example, 0 ≤ m ≤ O2N2. For another example, m can be at least one of {0, 2, 4, 6, 8}. For another example, m can be at least one of {0, 1, 2, 3}. For another example, m can be 0 or 1. For another example, m can be 0. In some embodiments, the number of precoding matrices in the second subset corresponding to 7 layers can be 128 or 32 or 16 or 8 or 4 or 2.

[0182] In some embodiments, N1 can be equal to 4, N2 is equal to 1, O1 can be equal to 2, and O2 can be equal to 1, and i 1,1It can be one of the following: {0, …, N1O1 - 1} or {0, 2, 4, 6} or {0, 4} or {0, 1} or 0 or {0, …, N1O1 / 2 - 1} or {0, 2}. The first subset of precoding matrices corresponding to 7 layers (e.g., "Set_f7_1") can include 16 precoding matrices. In some embodiments, the first subset of precoding matrices "Set_f7_1" can include 8 precoding matrices. Alternatively, the first subset of precoding matrices "Set_f7_1" can include 4 precoding matrices. In other embodiments, the first subset of precoding matrices "Set_f7_1" can include 2 precoding matrices.

[0183] Alternatively, N1 can be equal to 2, N2 can be equal to 2, O1 can be equal to 1 or 4, and O2 can be equal to 2 or 4, i 1,1 or i 1,2 It can be one of the following: {0, …, 7} or {0, 2, 4, 6} or {0, 4} or {0, …, 3} or {0, 2} or {0, 1} or 0. The second subset of precoding matrices corresponding to 7 layers (e.g., "Set_f7_2") can include 128 precoding matrices. In some embodiments, the second subset of precoding matrices "Set_f7_2" can include 32 precoding matrices. Alternatively, the second subset of precoding matrices "Set_f7_2" can include 8 precoding matrices. In other embodiments, the second subset of precoding matrices "Set_f7_2" can include 2 precoding matrices.

[0184] In some embodiments, the terminal device 110 is indicated to have 7 layers, and there may be a second set of precoding matrices corresponding to 7 layers (e.g., the second set of partial interference precoding matrices). For example, if the terminal device 110 has 8 antenna ports, or if the PUSCH transmission of the terminal device 110 is associated with 8 antenna ports, or if the PUSCH transmission of the terminal device 110 is associated with an SRS having 8 ports, then 4 antenna ports (e.g., the first set of 4 ports) may be coherent, and the other 4 antenna ports (e.g., the second set of 4 ports) may be coherent. For example, the first set of 4 ports may be non - coherent with the second set of 4 ports. In some embodiments, there may be a second set of precoding matrices corresponding to 7 layers (e.g., the second set of partial interference precoding matrices), such as denoted as "Set_p7_1", and the size of the partial interference precoding matrix may be 7 by 8 or 8 by 7. In some embodiments, the precoding matrix may have 7 columns or rows. In some embodiments, there may be 8 elements in a column or row of the precoding matrix. In some embodiments, for a column or row of the partial interference precoding matrix, 4 of the 8 elements in the partial coherence matrix may have non - zero values. And the other 4 elements in the partial interference precoding matrix may have a value of 0. In some embodiments, there may be 4 columns or rows (e.g., the first set of 4 columns or rows) out of 7 columns or rows in the precoding matrix, and in each column or row, the non - zero values may be mapped to 4 of the 8 elements, and 0 may be mapped to the other 4 elements. For example, the indices of the 4 elements with non - zero values may be the same in the first set of 4 columns or rows. For example, the indices of the 4 elements with non - zero values may be idx_1, and idx_1 may be 4 values from {0,1,2,3,4,5,6,7} or {1,2,3,4,5,6,7,8}. For example, idx_1 may be {0,1,2,3} or {0,2,4,6} or {1,2,3,4} or {1,3,5,7}. In some embodiments, the 4 values of idx_1 may be based on the indices of the 4 antenna ports in the first set. In some embodiments, for the other 3 columns or rows (e.g., the second set of 3 columns or rows) out of 7 columns or rows in the precoding matrix, in each column or row, the non - zero values may be mapped to 4 of the 8 elements, and 0 may be mapped to the other 4 elements. For example, in the second set of 3 columns or rows, the indices of the 4 elements with non - zero values may be the same. For example, the indices of the 4 elements with non - zero values may be idx_2, and idx_2 may be 4 values from {0,1,2,3,4,5,6,7} or {1,2,3,4,5,6,7,8}. In some embodiments, the 4 values of idx_2 may be based on the indices of the 4 antenna ports in the second set. For example, idx_2 may be {4,5,6,7} or {1,3,5,7} or {5,6,7,8} or {2,4,6,8}.In some embodiments, any value of idx_1 can be different from any value of idx_2.

[0185] In some embodiments, there can be two sets of vectors of length 4, and each set can include 4 vectors of length 4. In some embodiments, the values in the vectors of length 4 can be applied to map to 4 non-zero values of 4 elements among the columns or rows of a precoding matrix. For example, the first set of vectors of length 4 can be {[1; 1; 1; 1], [1; -1; 1; -1], [1; 1; -1; -1], [1; -1; -1; 1]}. As another example, the second set of vectors of length 4 can be {[1; 1; j; j], [1; -1; j; -j], [1; 1; -j; -j], [1; -1; -j; j]}. In some embodiments, the 4 values in each vector in the first set or the second set can be mapped to 4 elements among 8 elements, and 0 can be mapped to the other 4 elements in the columns or rows of the precoding matrix. In some embodiments, a set of precoding matrices "Set_p7_1" can include C(2,1)*C(7,4)*C(2,1)*C(4,3) precoding matrices.

[0186] In some embodiments, an example of a precoding matrix in the second set of precoding matrices corresponding to 7 layers can be as follows: or

[0187] For example, rows or columns can be swapped. For example, each of [a1, a2, a3, a4], [b1, b2, b3, b4], [c1, c2, c3, c4], and [d1, d2, d3, d4] can be one of the vectors of length 4 in the first set of vectors of length 4 or the second set of vectors of length 4. For example, each of [e1, e2, e3, e4], [f1, f2, f3, f4], [g1, g2, g3, g4] can be one of the vectors of length 4 in the first set of vectors of length 4 or the second set of vectors of length 4. For example, [a1, a2, a3, a4], [b1, b2, b3, b4], [c1, c2, c3, c4], and [d1, d2, d3, d4] can be [1; 1; 1; 1], [1; -1; 1; -1], [1; 1; -1; -1], and [1; -1; -1; 1], respectively. For another example, [a1, a2, a3, a4], [b1, b2, b3, b4], [c1, c2, c3, c4], and [d1, d2, d3, d4] can be [1; 1; j; j], [1; -1; j; -j], [1; 1; -j; -j], and [1; -1; -j; j], respectively. For example, [e1, e2, e3, e4], [f1, f2, f3, f4], [g1, g2, g3, g4] can be 3 of the vectors [1; 1; 1; 1], [1; -1; 1; -1], [1; 1; -1; -1], and [1; -1; -1; 1]. For another example, [e1, e2, e3, e4], [f1, f2, f3, f4], [g1, g2, g3, g4]] can be 3 of the vectors [1; 1; j; j], [1; -1; j; -j], [1; 1; -j; -j], and [1; -1; -j; j].

[0188] In some embodiments, s7 can be a positive integer. For example, 1 ≤ s7 ≤ 64. For example, s7 can be 64 or 32 or 16 or 8 or 4 or 2 or 56 or 28 or 14.

[0189] In some embodiments, if the terminal device 110 is indicated to have 7 layers, there may be a third set of precoding matrices (e.g., a third set of partial interference precoding matrices) corresponding to 7 layers. For example, the structure of 8 ports can be 2+2+2+2, which means there are 4 groups, each group including 2 antenna ports, and within each group, the 2 antenna ports can be coherent. For example, between groups, the antenna ports may not be coherent. In some embodiments, there may be a third set of precoding matrices (e.g., a third set of partial interference precoding matrices), such as denoted as "Set_p7_2", and the size of the precoding matrix can be 7 by 8 or 8 by 7. In some embodiments, the precoding matrix can have 7 columns or rows. In some embodiments, there can be 8 elements in a column or row of the precoding matrix. In some embodiments, for a column or row of the precoding matrix, 2 out of the 8 elements in the precoding matrix can have non-zero values. And the other 6 elements in the precoding matrix can have a value of 0. In some embodiments, there can be 2 columns or rows (e.g., the first set of 2 columns or rows) out of 7 columns or rows in the precoding matrix, and in each column or row, the non-zero values can be mapped to 2 out of the 8 elements, and 0 can be mapped to the other 6 elements. For example, in the first set of 2 columns or rows, the indices of the 2 elements with non-zero values can be the same. For example, the indices of the 2 elements with non-zero values can be idx_1, and idx_1 can be 2 values from {0,1,2,3,4,5,6,7} or {1,2,3,4,5,6,7,8}. In some embodiments, the 2 values of idx_1 can be based on the indices of two antenna ports out of the 4 antenna ports in the first group. In some embodiments, the 2 values of idx_1 can be based on the indices of 2 antenna ports in the third group. For example, idx_1 can be {0,1} or {0,2} or {1,2} or {1,3} or {0,4} or {1,5}. In some embodiments, there can be 2 columns or rows (e.g., the second set of 2 columns or rows) out of 7 columns or rows in the precoding matrix, and in each column or row, the non-zero values can be mapped to 2 out of the 8 elements, and 0 can be mapped to the other 6 elements. For example, in the second set of 2 columns or rows, the indices of the 2 elements with non-zero values can be the same. For example, the indices of the 2 elements with non-zero values can be idx_2, and idx_2 can be 2 values from {0,1,2,3,4,5,6,7} or {1,2,3,4,5,6,7,8}. In some embodiments, the 2 values of idx_2 can be based on the indices of the other two antenna ports out of the 4 antenna ports in the first group. In some embodiments, the 2 values of idx_2 can be based on the indices of 2 antenna ports in the fourth group. For example, idx_2 can be {2,3} or {1,3} or {3,4} or {2,4} or {1,5} or {2,6}.In some embodiments, in a precoding matrix, there may be 2 columns or rows out of 7 columns or rows (e.g., the third group of 2 columns or rows), and in each column or row, non-zero values may be mapped to 2 elements out of 8 elements, and 0 may be mapped to the other 6 elements. For example, in the third group of 2 columns or rows, the indices of the 2 elements with non-zero values may be the same. For example, the indices of the 2 elements with non-zero values may be idx_3, and idx_3 may be 2 values from {0, 1, 2, 3, 4, 5, 6, 7} or {1, 2, 3, 4, 5, 6, 7, 8}. In some embodiments, the 2 values of idx_3 may be based on the indices of two antenna ports out of the 4 antenna ports in the second group. In some embodiments, the 2 values of idx_3 may be based on the indices of 2 antenna ports in the fifth group. For example, idx_3 may be {4, 5} or {4, 6} or {5, 6} or {5, 7} or {2, 6} or {3, 7}. In some embodiments, in a precoding matrix, there may be 1 column or row out of 7 columns or rows (e.g., the fourth group of 1 column or row), and in each column or row, non-zero values may be mapped to 2 elements out of 8 elements, and 0 may be mapped to the other 6 elements. For example, in the fourth group of 1 column or row, the indices of the 2 elements with non-zero values may be the same. For example, the indices of the 2 elements with non-zero values may be idx_4, and idx_4 may be 2 values from {0, 1, 2, 3, 4, 5, 6, 7} or {1, 2, 3, 4, 5, 6, 7, 8}. In some embodiments, the 2 values of idx_4 may be based on the indices of the remaining two antenna ports out of the 4 antenna ports in the second group. In some embodiments, the 2 values of idx_4 may be based on the indices of 2 antenna ports in the sixth group. For example, idx_4 may be {6, 7} or {5, 7} or {7, 8} or {6, 8} or {3, 7} or {4, 8}. In some embodiments, any value of idx_1, any value of idx_2, any value of idx_3, and any value of idx_4 may be different from each other.

[0190] In some embodiments, there can be a set of 4 vectors of length 2, and each of the vectors of length 2 can be applied as two non-zero values in a column or a row of a precoding matrix. In some embodiments, for a third set of precoding matrices corresponding to 7 layers, e.g., Set_p7_2, two vectors of length 2 can be selected from the 4 vectors of length 2, and the 2 values in each vector can be mapped to 2 of the 8 elements, and 0 can be mapped to the other elements in a column or a row of the precoding matrix. In some embodiments, there can be two sets of vectors of length 2, and each set can include 2 vectors of length 2. In some embodiments, the two values in a vector of length 2 can be applied as two non-zero values mapped to 2 elements in a column or a row of a precoding matrix. For example, the first set of vectors of length 2 can be {[1; 1], [1; -1]}. As another example, the second set of vectors of length 2 can be {[1; j], [1; -j]}. In some embodiments, the 2 values in each vector in the first set or the second set can be mapped to 2 of the 8 elements, and 0 can be mapped to the other 6 elements in a column or a row of the precoding matrix.

[0191] In some embodiments, for the first set of 2 columns or rows and / or the second set of 2 columns or rows and / or the third set of 2 columns or rows and / or the fourth set of 1 column or row, the two vectors for the two non-zero values selected to be mapped to 2 of the 8 elements in each column or row can be {[1; 1] and [1; -1]} or {[1; j] and [1; -j]}.

[0192] In some embodiments, an example of a precoding matrix in the third set of precoding matrices corresponding to 7 layers can be as follows: or For example, rows or columns can be swapped. For example, each of [a1, a2], [b1, b2] can be one of the vectors of length 2 in the first set of vectors of length 2 or the second set of vectors of length 2. For example, each of [c1, c2] and [d1, d2] can be one of the vectors of length 2 in the first set of vectors of length 2 or the second set of vectors of length 2. For example, each of [e1, e2], [f1, f2] can be one of the vectors of length 2 in the first set of vectors of length 2 or the second set of vectors of length 2. For example, [g1, g2] can be one of the vectors of length 2 in the first set of vectors of length 2 or the second set of vectors of length 2. For example, [a1, a2], [b1, b2] can be [1; 1], [1; -1] respectively. Again for example, [a1, a2], [b1, b2] can be [1; j], [1; -j] respectively. For example, [c1, c2] and [d1, d2] can be [1; 1], [1; -1] respectively. Again for example, [c1, c2] and [d1, d2] can be [1; j], [1; -j] respectively. For example, [e1, e2], [f1, f2] can be [1; 1], [1; -1] respectively. Again for example, [e1, e2], [f1, f2] can be [1; j], [1; -j] respectively. For example, [g1, g2] can be one of [1; 1], [1; -1]. Again for example, [g1, g2] can be one of [1; j], [1; -j] respectively.

[0193] In some embodiments, if the terminal device 110 is indicated to have 7 layers, there may be a fourth set of precoding matrices (e.g., a fourth set of non-coherent precoding matrices) corresponding to 7 layers. For example, each of the 8 antenna ports may be non-coherent with each other. In some embodiments, there may be a fourth set of precoding matrices (e.g., a fourth set of non-coherent precoding matrices), such as denoted as "Set_n7_1", and the size of the precoding matrix may be 7 by 8 or 8 by 7. In some embodiments, the precoding matrix may have 7 columns or rows. In some embodiments, there may be 8 elements in a column or row of the precoding matrix. In some embodiments, for a column or row of the precoding matrix, 1 element out of the 8 elements in the precoding matrix may have a non-zero value. For example, the non-zero value may be 1. And the other 7 elements in the precoding matrix may have a value of 0. In some embodiments, for each of the 7 columns or rows in the precoding matrix, the non-zero value may be mapped to 1 element out of the 8 elements, and 0 may be mapped to the other 7 elements. For example, in each row or column of the precoding matrix, the index of the element with the non-zero value may be different. For example, the indexes of the 1 element with the non-zero value may be idx_1, idx_2, idx_3, idx_4, idx_5, idx_6, idx_7 for the first, second, third, fourth, fifth, sixth, seventh columns or rows of the precoding matrix respectively, and for each of idx_1, idx_2, idx_3, idx_4, idx_5, idx_6, idx_7, the value may be 1 value from {0, 1, 2, 3, 4, 5, 6, 7} or {1, 2, 3, 4, 5, 6, 7, 8}. For example, the values of idx_1, idx_2, idx_3, idx_4, idx_5, idx_6, idx_7 may be 0, 1, 2, 3, 4, 5, 6 respectively. Again for example, the values of idx_1, idx_2, idx_3, idx_4, idx_5, idx_6, idx_7 may be 1, 2, 3, 4, 5, 6, 7 respectively. In some embodiments, the values of idx_1, idx_2, idx_3, idx_4 may be based on the indexes of 4 antenna ports in the first set. In some embodiments, the values of idx_5, idx_6 and idx_7 may be based on the indexes of three antenna ports out of 4 antenna ports in the second set. In some embodiments, the values of idx_1, idx_2 may be based on the indexes of 2 antenna ports in the third set. In some embodiments, the values of idx_3, idx_4 may be based on the indexes of 2 antenna ports in the fourth set. In some embodiments, the values of idx_5, idx_6 may be based on the indexes of 2 antenna ports in the fifth set. In some embodiments, the value of idx_7 may be based on the index of one antenna port out of 2 antenna ports in the sixth set.For example, the values of idx_1, idx_2, idx_3, idx_4, idx_5, idx_6, and idx_7 may be different from each other.

[0194] In some embodiments, if the terminal device 110 is indicated as having 7 layers, there may be a fourth set of precoding matrices corresponding to 7 layers. For example, there may be only one precoding matrix (e.g., a non-interfering precoding matrix) in the fourth set corresponding to 7 layers.

[0195] In some embodiments, if the terminal device 110 is indicated as having 7 layers, there may be a fifth set of precoding matrices (e.g., a hybrid partially interfering precoding matrix) corresponding to 7 layers. For example, the structure of 8 ports may be 4+2+2, which means that 4 antenna ports may be coherent, 2 antenna ports may be coherent, and the other 2 antenna ports may be coherent. In this case, 4 columns out of 8 columns may be mapped with vectors of length 4, and for the remaining 3 columns, each column may be mapped with vectors of length 2, and port swapping may occur.

[0196] In other embodiments, if the terminal device 110 is indicated as having 7 layers, there may be a sixth set of precoding matrices (e.g., a hybrid of partially and non-interfering precoding matrices) corresponding to 7 layers. For example, the structure of 8 antenna ports may be 4+1+1+1+1, which means that 4 antenna ports may be coherent.

[0197] In some embodiments, if the terminal device 110 is indicated as having 7 layers, there may be a seventh set of precoding matrices (e.g., a hybrid of partially and non-interfering precoding matrices) corresponding to 7 layers. For example, the structure of 8 ports may be 4+2+1+1, which means that 4 antenna ports may be coherent, and 2 antenna ports may be coherent.

[0198] In other embodiments, if the terminal device 110 is indicated as having 7 layers, there may be an eighth set of precoding matrices (e.g., a hybrid of partially and non-interfering precoding matrices) corresponding to 7 layers. For example, the structure of 8 ports may be 2+2+1+1+1+1, which means that 2 antenna ports may be coherent, and 2 antenna ports may be coherent.

[0199] In some embodiments, the terminal device 110 is indicated as having 6 layers, there may be a first set of precoding matrices (e.g., a first set of fully coherent precoding matrices) corresponding to 6 layers, and the fully coherent precoding matrix may be expressed as:

[0200] In some embodiments, may be

[0201] In some embodiments, may be

[0202] In some embodiments, P may be 8 or 12 or 16. In some embodiments, l may be a non - negative integer. For example, 0≤l≤O1N1. For another example, 0≤l≤O1N1 / 2. For another example, l may be at least one of {0, 2, 4, 6, 8}. For another example, l may be at least one of {0, 1, 2, 3}. For another example, l may be 0 or 1. In some embodiments, m may be a non - negative integer. For example, 0≤m≤O2N2. For another example, m may be at least one of {0, 2, 4, 6, 8}. For another example, m may be at least one of {0, 1, 2, 3}. For another example, m may be 0 or 1. For another example, m may be 0. In some embodiments, n may be a non - negative integer. For example, n may be at least one of {0, 1, 2, 3}. For another example, n may be 0 or 1. For another example, n may be 0 or 2. For another example, n may be 0. In some embodiments, l′ = l + O1. In some embodiments, l″ = l + 2O1. In some embodiments, m and m′ and m″ may be 0. In some embodiments, l′ = l + O1. In some embodiments, l″ = l + O1. In some embodiments, m′ = m. In some embodiments, m″ = m + O2.

[0203] In some embodiments, there may be more than one subset of precoding matrices corresponding to 6 layers. In some embodiments, the first set of precoding matrices corresponding to 6 layers may include more than one subset. For example, there may be two subsets of precoding matrices.

[0204] In some embodiments, there may be a first subset of precoding matrices corresponding to 6 layers, and corresponding to the first subset of precoding matrices, the value of "N1" may be 4, the value of "N2" may be 1, and the value of "O1" may be 4 or 2 or 1. For example, the value of "O2" may be 1. In some embodiments, corresponding to the first subset, In some embodiments, corresponding to the first subset, m and m′ and m″ may be 0. In some embodiments, corresponding to the first subset, l′ = l + O1, l″ = l + 2O1. In some embodiments, corresponding to the first subset, l may be a non - negative integer, 0≤l≤O1N1. For example, l may be at least one of {0, 2, 4, 6}. For another example, l may be at least one of {0, 1, 2, 3}. For another example, l may be 0 or 1. For another example, l may be 0 or 2. In some embodiments, the number of precoding matrices in the first subset corresponding to 6 layers may be 32 or 16 or 8 or 4 or 2.

[0205] In some embodiments, there may be a second subset of precoding matrices corresponding to 6 layers, and corresponding to the second subset of precoding matrices, the value of "N1" may be 2, the value of "N2" may be 2, and the value of "O1" may be 4 or 2 or 1. For example, the value of "O2" may be 4 or 2 or 1. In some embodiments, corresponding to the second subset, In some embodiments, corresponding to the second subset, l′ = l + O1, l″ = l + O1. In some embodiments, corresponding to the second subset, m′ = m, m″ = m + O2. In some embodiments, corresponding to the second subset, l may be a non - negative integer, 0 ≤ l ≤ O1N1. For example, l may be at least one of {0, 2, 4, 6}. Again, for example, l may be at least one of {0, 1, 2, 3}. Again, for example, l may be 0 or 1. Again, for example, l may be 0 or 2. In some embodiments, corresponding to the second subset, m may be a non - negative integer. For example, 0 ≤ m ≤ O2N2. Again, for example, m may be at least one of {0, 2, 4, 6, 8}. Again, for example, m may be at least one of {0, 1, 2, 3}. Again, for example, m may be 0 or 1. Again, for example, m may be 0. In some embodiments, the number of precoding matrices in the second subset corresponding to 6 layers may be 128 or 32 or 16 or 8 or 4 or 2.

[0206] In some embodiments, N1 may be equal to 4, N2 equal to 1, O1 may be equal to 2, and O2 may be equal to 1, and i 1,1 may be one of the following: {0, … N1O1 - 1} or {0, 2, 4, 6} or {0, 4} or {0, 1} or 0 or {0, … N1O1 / 2 - 1} or {0, 2}. Corresponding to the first subset of precoding matrices for 6 layers, for example, "Set_f6_1" may include 16 precoding matrices. In some embodiments, the first subset of precoding matrices "Set_f6_1" may include 8 precoding matrices. Alternatively, the first subset of precoding matrices "Set_f6_1" may include 4 precoding matrices. In other embodiments, the first subset of precoding matrices "Set_f6_1" may include 2 precoding matrices.

[0207] Alternatively, N1 may be equal to 2, N2 equal to 2, O1 may be equal to 1 or 4, and O2 may be equal to 2 or 4, i 1,1 or i 1,2It can be one of the following: {0, … 7} or {0, 2, 4, 6} or {0, 4} or {0, … 3} or {0, 2} or {0, 1} or 0. Corresponding to the second subset of precoding matrices for 6 layers, for example, "Set_f6_2" can include 128 precoding matrices. In some embodiments, the second subset of precoding matrices "Set_f6_2" can include 32 precoding matrices. Alternatively, the second subset of precoding matrices "Set_f6_2" can include 8 precoding matrices. In other embodiments, the second subset of precoding matrices "Set_f6_2" can include 2 precoding matrices.

[0208] In some embodiments, the terminal device 110 is indicated to have 6 layers, and there may be a second set of precoding matrices (e.g., a second set of partially coherent precoding matrices) corresponding to 6 layers. For example, if the terminal device 110 has 8 antenna ports, or if the PUSCH transmission of the terminal device 110 is associated with 8 antenna ports, or if the PUSCH transmission of the terminal device 110 is associated with an SRS having 8 ports, then 4 antenna ports (e.g., the first set of 4 ports) may be coherent, and the other 4 antenna ports (e.g., the second set of 4 ports) may be coherent. For example, the first set of 4 ports may be non - coherent with the second set of 4 ports. In some embodiments, there may be a second set of precoding matrices (e.g., a second set of partially coherent precoding matrices) corresponding to 6 layers, e.g., denoted as "Set_p6_1", and the size of the partially coherent precoding matrix may be 6 by 8 or 8 by 6. In some embodiments, the precoding matrix may have 6 columns or rows. In some embodiments, there may be 8 elements in a column or row of the precoding matrix. In some embodiments, for a column or row of the partially coherent precoding matrix, 4 of the 8 elements in the partially coherent matrix may have non - zero values. And the other 4 elements in the partially coherent precoding matrix may have a value of 0. In some embodiments, there may be 4 columns or rows (e.g., the first set of 4 columns or rows) out of 6 columns or rows in the precoding matrix, and in each column, the non - zero values may be mapped to 4 of the 8 elements, and 0 for the other 4 elements. For example, in the first set of 4 columns or rows, the indices of the 4 elements with non - zero values may be the same. For example, the indices of the 4 elements with non - zero values may be idx_1, and idx_1 may be 4 values from {0,1,2,3,4,5,6,7} or {1,2,3,4,5,6,7,8}. For example, idx_1 may be {0,1,2,3} or {0,2,4,6} or {1,2,3,4} or {1,3,5,7}. In some embodiments, the 4 values of idx_1 may be based on the indices of the 4 antenna ports in the first set. In some embodiments, for the other 2 columns, 2 vectors of length 4 from the first set or 2 vectors of length 4 from the second set may be selected. In some embodiments, for the other 2 columns or rows (e.g., the second set of 2 columns or rows) out of 6 columns or rows in the precoding matrix, in each column or row, the non - zero values may be mapped to 4 of the 8 elements, and 0 may be mapped to the other 4 elements. For example, in the second set of 2 columns or rows, the indices of the 4 elements with non - zero values may be the same. For example, the indices of the 4 elements with non - zero values may be idx_2, and idx_2 may be 4 values from {0,1,2,3,4,5,6,7} or {1,2,3,4,5,6,7,8}. In some embodiments, the 4 values of idx_2 may be based on the indices of two antenna ports out of the 4 antenna ports in the second set.For example, idx_2 can be {4, 5, 6, 7} or {1, 3, 5, 7} or {5, 6, 7, 8} or {2, 4, 6, 8}. In some embodiments, any value of idx_1 can be different from any value of idx_2. In some embodiments, alternatively, 3 columns or rows out of 6 columns or rows can be selected (e.g., the first group of 3 columns or rows). In each column, non-zero values can be mapped to 4 out of 8 elements, and 0 can be mapped to the other 4 elements. For example, in the first group of 3 columns or rows, the indices of the 4 elements with non-zero values can be the same. For example, the indices of the 4 elements with non-zero values can be idx_1, and idx_1 can be 4 values out of {0, 1, 2, 3, 4, 5, 6, 7} or {1, 2, 3, 4, 5, 6, 7, 8}. In some embodiments, the 4 values of idx_1 can be based on the indices of 4 antenna ports in the first group. For example, idx_1 can be {0, 1, 2, 3} or {0, 2, 4, 6} or {1, 2, 3, 4} or {1, 3, 5, 7}. In some embodiments, for the other 3 columns or rows, 3 vectors of length 4 from the first group of vectors of length 4 or the second group of vectors of length 4 can be selected. In some embodiments, for the other 3 columns, 3 out of the first group of vectors of length 4 or the second group of vectors of length 4 can be selected. In some embodiments, for the other 3 columns or rows out of 6 columns or rows in the precoding matrix (e.g., the second group of 3 columns or rows), in each column or row, non-zero values can be mapped to 4 out of 8 elements, and 0 can be mapped to the other 4 elements. For example, in the second group of 3 columns or rows, the indices of the 4 elements with non-zero values can be the same. For example, the indices of the 4 elements with non-zero values can be idx_2, and idx_2 can be 4 values out of {0, 1, 2, 3, 4, 5, 6, 7} or {1, 2, 3, 4, 5, 6, 7, 8}. In some embodiments, the 4 values of idx_2 can be based on the indices of 4 antenna ports in the first group. For example, idx_2 can be {4, 5, 6, 7} or {1, 3, 5, 7} or {5, 6, 7, 8} or {2, 4, 6, 8}. In some embodiments, any value of idx_1 can be different from any value of idx_2.

[0209] In some embodiments, there may be two sets of vectors of length 4, and each set may include 4 vectors of length 4. In some embodiments, the values in the vectors of length 4 may be applied to the 4 non-zero values that map to 4 elements in the columns or rows of the precoding matrix. For example, the first set of vectors of length 4 may be {[1; 1; 1; 1], [1; -1; 1; -1], [1; 1; -1; -1], [1; -1; -1; 1]}. As another example, the second set of vectors of length 4 may be {[1; 1; j; j], [1; -1; j; -j], [1; 1; -j; -j], [1; -1; -j; j]}. In some embodiments, the 4 values in each vector in the first set or the second set may be mapped to 4 of the 8 elements, and 0 may be mapped to the other 4 elements in the columns or rows of the precoding matrix.

[0210] In some embodiments, an example of the precoding matrix in the second set of precoding matrices corresponding to 6 layers may be as follows: or For example, rows or columns can be swapped. For example, rows or columns can be swapped. For example, each of [a1, a2, a3, a4], [b1, b2, b3, b4], [c1, c2, c3, c4], and [d1, d2, d3, d4] can be one of the vectors of length 4 in the first set of vectors of length 4 or the second set of vectors of length 4. For example, each of [e1, e2, e3, e4] and [f1, f2, f3, f4] can be one of the vectors of length 4 in the first set of vectors of length 4 or the second set of vectors of length 4. For example, [a1, a2, a3, a4], [b1, b2, b3, b4], [c1, c2, c3, c4], and [d1, d2, d3, d4] can be [1; 1; 1; 1], [1; -1; 1; -1], [1; 1; -1; -1], and [1; -1; -1; 1], respectively. For another example, [a1, a2, a3, a4], [b1, b2, b3, b4], [c1, c2, c3, c4], and [d1, d2, d3, d4] can be [1; 1; j; j], [1; -1; j; -j], [1; 1; -j; -j], and [1; -1; -j; j], respectively. For example, [e1, e2, e3, e4] and [f1, f2, f3, f4] can be two of the vectors [1; 1; 1; 1], [1; -1; 1; -1], [1; 1; -1; -1], and [1; -1; -1; 1]. For another example, [e1, e2, e3, e4] and [f1, f2, f3, f4] can be two of the vectors [1; 1; j; j], [1; -1; j; -j], [1; 1; -j; -j], and [1; -1; -j; j]. For example, each of [a1, a2, a3, a4], [b1, b2, b3, b4], and [c1, c2, c3, c4] can be one of the vectors of length 4 in the first set of vectors of length 4 or the second set of vectors of length 4. For example, each of [d1, d2, d3, d4], [e1, e2, e3, e4], and [f1, f2, f3, f4] can be one of the vectors of length 4 in the first set of vectors of length 4 or the second set of vectors of length 4. For example, [a1, a2, a3, a4], [b1, b2, b3, b4], and [c1, c2, c3, c4] can be three of the vectors [1; 1; 1; 1], [1; -1; 1; -1], [1; 1; -1; -1], and [1; -1; -1; 1]. For another example, [a1, a2, a3, a4], [b1, b2, b3, b4], and [c1, c2, c3, c4] can be three of [1; 1; j; j], [1; -1; j; -j], [1; 1; -j; -j], and [1; -1; -j; j].For example, [d1, d2, d3, d4], [e1, e2, e3, e4], [f1, f2, f3, f4] can be three vectors among [1; 1; 1; 1], [1; -1; 1; -1], [1; 1; -1; -1], and [1; -1; -1; 1]. For another example, [d1, d2, d3, d4], [e1, e2, e3, e4], [f1, f2, f3, f4] can be three vectors among [1; 1; j; j], [1; -1; j; -j], [1; 1; -j; -j], and [1; -1; -j; j].

[0211] In some embodiments, s6 can be a positive integer. For example, 1 ≤ s6 ≤ 64. For example, s6 can be 64 or 32 or 16 or 8 or 4 or 2 or 48 or 24 or 12.

[0212] In some embodiments, if the terminal device 110 is indicated to have 6 layers, there may be a third set of precoding matrices (e.g., a third set of partial interference precoding matrices) corresponding to 6 layers. For example, the structure of 8 ports can be 2+2+2+2, which means there are 4 groups, each group including 2 antenna ports, and within each group, the 2 antenna ports can be coherent. For example, between groups, the antenna ports may not be coherent. In some embodiments, there may be a third set of precoding matrices (e.g., a third set of partial interference precoding matrices), such as denoted as "Set_p6_2", and the size of the precoding matrix can be 6 by 8 or 8 by 6. In some embodiments, the precoding matrix can have 6 columns or rows. In some embodiments, there can be 8 elements in a column or row of the precoding matrix. In some embodiments, for a column or row of the precoding matrix, 2 out of the 8 elements in the precoding matrix can have non-zero values. And the other 6 elements in the precoding matrix can have a value of 0. In some embodiments, there can be 2 columns or rows (e.g., the first set of 2 columns or rows) out of 6 columns or rows in the precoding matrix, and in each column or row, the non-zero values can be mapped to 2 out of the 8 elements, and 0 can be mapped to the other 6 elements. For example, in the first set of 2 columns or rows, the indices of the 2 elements with non-zero values can be the same. For example, the indices of the 2 elements with non-zero values can be idx_1, and idx_1 can be 2 values from {0,1,2,3,4,5,6,7} or {1,2,3,4,5,6,7,8}. In some embodiments, the 2 values of idx_1 can be based on the indices of two antenna ports out of the 4 antenna ports in the first group. In some embodiments, the 2 values of idx_1 can be based on the indices of 2 antenna ports in the third group. For example, idx_1 can be {0,1} or {0,2} or {1,2} or {1,3} or {0,4} or {1,5}. In some embodiments, there can be 2 columns or rows (e.g., the second set of 2 columns or rows) out of 6 columns or rows in the precoding matrix, and in each column or row, the non-zero values can be mapped to 2 out of the 8 elements, and 0 can be mapped to the other 6 elements. For example, in the second set of 2 columns or rows, the indices of the 2 elements with non-zero values can be the same. For example, the indices of the 2 elements with non-zero values can be idx_2, and idx_2 can be 2 values from {0,1,2,3,4,5,6,7} or {1,2,3,4,5,6,7,8}. In some embodiments, the 2 values of idx_2 can be based on the indices of the remaining two antenna ports out of the 4 antenna ports in the first group. In some embodiments, the 2 values of idx_2 can be based on the indices of 2 antenna ports in the fourth group. For example, idx_2 can be {2,3} or {1,3} or {3,4} or {2,4} or {1,5} or {2,6}.In some embodiments, there may be 1 or 2 columns or rows out of 6 columns or rows in the precoding matrix (e.g., the third group of 1 or 2 columns or rows), and in each column or row, non-zero values may be mapped to 2 out of 8 elements, and 0 may be mapped to the other 6 elements. For example, in the third group of 1 or 2 columns or rows, the indices of the 2 elements with non-zero values may be the same. For example, the indices of the 2 elements with non-zero values may be idx_3, and idx_3 may be 2 values from {0, 1, 2, 3, 4, 5, 6, 7} or {1, 2, 3, 4, 5, 6, 7, 8}. In some embodiments, the 2 values of idx_1 may be based on the indices of two antenna ports out of the 4 antenna ports in the second group. In some embodiments, the 2 values of idx_1 may be based on the indices of 2 antenna ports in the fifth group. For example, idx_3 may be {4, 5} or {4, 6} or {5, 6} or {5, 7} or {2, 6} or {3, 7}. In some embodiments, there may be 1 or 2 columns or rows out of 6 columns or rows in the precoding matrix (e.g., the fourth group of 1 or 2 columns or rows), and in each column or row, non-zero values may be mapped to 2 out of 8 elements, and 0 may be mapped to the other 6 elements. For example, in the fourth group of 1 or 2 columns or rows, the indices of the 2 elements with non-zero values may be the same. For example, the indices of the 2 elements with non-zero values may be idx_4, and idx_4 may be 2 values from {0, 1, 2, 3, 4, 5, 6, 7} or {1, 2, 3, 4, 5, 6, 7, 8}. In some embodiments, the 2 values of idx_4 may be based on the indices of the remaining two antenna ports out of the 4 antenna ports in the second group. In some embodiments, the 2 values of idx_4 may be based on the indices of 2 antenna ports in the sixth group. For example, idx_4 may be {6, 7} or {5, 7} or {7, 8} or {6, 8} or {3, 7} or {4, 8}. In some embodiments, any value of idx_1, any value of idx_2, any value of idx_3, and any value of idx_4 may be different from each other. In some embodiments, the total number of columns or rows in the first group and / or the second group and / or the third group and / or the fourth group may be 6. In some embodiments, there may be a first group, a second group, and a third group, and each group has 2 columns or rows. In some embodiments, there may be a first group, a second group, and a third group and a fourth group, and each of two of the four groups has 2 columns or rows, and each of the other two of the four groups has 1 column or row.

[0213] In some embodiments, there may be a set of 4 vectors of length 2, and each of the vectors of length 2 may be applied as two non-zero values in a column or a row of a precoding matrix. In some embodiments, for a third set of precoding matrices corresponding to 6 layers, such as Set_p6_2, two vectors of length 2 may be selected from the 4 vectors of length 2, and the 2 values in each vector may be mapped to 2 of the 8 elements, and 0 may be mapped to the other elements in a column or a row of the precoding matrix. In some embodiments, there may be two sets of vectors of length 2, and each set may include 2 vectors of length 2. In some embodiments, the two values in a vector of length 2 may be applied as two non-zero values mapped to 2 elements in a column or a row of a precoding matrix. For example, the first set of vectors of length 2 may be {[1; 1], [1; -1]}. As another example, the second set of vectors of length 2 may be {[1; j], [1; -j]}. In some embodiments, the 2 values in each vector in the first set or the second set may be mapped to 2 of the 8 elements, and 0 may be mapped to the other 6 elements in a column or a row of the precoding matrix.

[0214] In some embodiments, for the first set of 2 columns or rows and / or for the second set of 2 columns or rows and / or for the third set of 1 or 2 columns or rows and / or for the fourth set of 1 or 2 columns or rows, the two vectors selected for mapping the two non-zero values to 2 of the 8 elements in each column or row may be {[1; 1] and [1; -1]} or {[1; j] and [1; -j]}.

[0215] In some embodiments, an example of a precoding matrix in the third set of precoding matrices corresponding to 6 layers may be as follows: or For example, rows or columns can be swapped. For example, each of [a1, a2], [b1, b2] can be one of the vectors of length 2 in the first group of vectors of length 2 or the second group of vectors of length 2. For example, each of [c1, c2] and [d1, d2] can be one of the vectors of length 2 in the first group of vectors of length 2 or the second group of vectors of length 2. For example, each of [e1, e2], [f1, f2] can be one of the vectors of length 2 in the first group of vectors of length 2 or the second group of vectors of length 2. For example, [a1, a2], [b1, b2] can be [1; 1], [1; -1] respectively. Again for example, [a1, a2], [b1, b2] can be [1; j], [1; -j] respectively. For example, [c1, c2] and [d1, d2] can be [1; 1], [1; -1] respectively. Again for example, [c1, c2] and [d1, d2] can be [1; j], [1; -j] respectively. For example, [e1, e2], [f1, f2] can be [1; 1], [1; -1] respectively. Again for example, [e1, e2], [f1, f2] can be [1; j], [1; -j] respectively. For example, [e1, e2] can be one of [1; 1], [1; -1], [1; j], [1; -j]. For example, [f1, f2] can be one of [1; 1], [1; -1], [1; j], [1; -j].

[0216] In some embodiments, if the terminal device 110 is indicated to have 6 layers, there may be a fourth set of precoding matrices (e.g., a fourth set of non-coherent precoding matrices) corresponding to 6 layers. For example, each of the 8 antenna ports may be non-coherent with each other. In some embodiments, there may be a fourth set of precoding matrices (e.g., a fourth set of non-coherent precoding matrices), e.g., denoted as "Set_n6_1", and the size of the precoding matrix may be 6 by 8 or 8 by 6. In some embodiments, the precoding matrix may have 6 columns or rows. In some embodiments, there may be 8 elements in the columns or rows of the precoding matrix. In some embodiments, for the columns or rows of the precoding matrix, 1 element out of the 8 elements in the precoding matrix may have a non-zero value. For example, the non-zero value may be 1. And the other 7 elements in the precoding matrix may have a value of 0. In some embodiments, for each of the 6 columns or rows in the precoding matrix, the non-zero value may be mapped to 1 element out of the 8 elements, and 0 may be mapped to the other 7 elements. For example, in each row or column of the precoding matrix, the index of the element with the non-zero value may be different. For example, the indices of the 1 element with the non-zero value may be idx_1, idx_2, idx_3, idx_4, idx_5, idx_6 for the first, second, third, fourth, fifth, sixth columns or rows of the precoding matrix respectively, and for each of idx_1, idx_2, idx_3, idx_4, idx_5, idx_6, the value may be 1 value from {0, 1, 2, 3, 4, 5, 6, 7} or {1, 2, 3, 4, 5, 6, 7, 8}. In some embodiments, the values of idx_1, idx_2, idx_3, idx_4 may be based on the indices of 4 antenna ports in the first set. In some embodiments, the values of idx_1, idx_2, idx_3 may be based on the indices of three antenna ports out of the 4 antenna ports in the first set. In some embodiments, the values of idx_1 and idx_2 may be based on the indices of 2 antenna ports in the third set. In some embodiments, the values of idx_3 and idx_4 may be based on the indices of 2 antenna ports in the fourth set. In some embodiments, the values of idx_5, idx_6 may be based on the indices of two antenna ports out of the 4 antenna ports in the second set. In some embodiments, the values of idx_5, idx_6 may be based on the indices of 2 antenna ports in the fifth set. In some embodiments, the values of idx_5, idx_6 may be based on the indices of 2 antenna ports in the sixth set. For example, the values of idx_1, idx_2, idx_3, idx_4, idx_5, idx_6 may be 0, 1, 2, 3, 4, 5 respectively. Or for another example, the values of idx_1, idx_2, idx_3, idx_4, idx_5, idx_6 may be 1, 2, 3, 4, 5, 6 respectively.For example, the values of idx_1, idx_2, idx_3, idx_4, idx_5, and idx_6 can be different from each other.

[0217] In some embodiments, if the terminal device 110 is indicated to have 6 layers, there may be a fourth set of precoding matrices corresponding to 6 layers. For example, there may be only one precoding matrix (e.g., a non-interfering precoding matrix) in the fourth set corresponding to 6 layers.

[0218] In some embodiments, if there are 6 layers at the terminal device 110, a hybrid partial coherence matrix may be supported. For example, the antenna structure may be 4+2+2, which means that 4 antenna ports may be coherent, 2 antenna ports may be coherent, and the other 2 antenna ports may be coherent. In this case, r1 (e.g., 2, 3, or 4) columns may be mapped with vectors of length 4, and 6-r1 columns may be mapped with vectors of length 2, and port swapping may occur.

[0219] In other embodiments, the antenna structure may be 4+1+1+1+1, which means that 4 antenna ports may be coherent. In this case, r1 (e.g., 2, 3, or 4) columns may have vectors of length 4, 6-r1 columns may have 1 on one element, and row swapping may occur.

[0220] In some embodiments, the antenna structure may be 4+2+1+1, which means that 4 antenna ports may be coherent and 2 antenna ports may be coherent. For example, r1 (e.g., 2, 3, or 4) columns may have vectors of length 4, and r2 (e.g., 0, 1, 2) columns may have vectors of length 2, and 6-r1-r2 columns may have 1 on one element.

[0221] In some other embodiments, the antenna structure may be 2+2+1+1+1+1, which means that 2 antenna ports may be coherent and 2 antenna ports may be coherent. For example, r1 (e.g., 2, 3, or 4) columns may have vectors of length 2, and 6-r1 columns may have 1 on one element.

[0222] In some embodiments, when the terminal device 110 is indicated to have 5 layers, there may be a first set of precoding matrices corresponding to 5 layers (e.g., the first set of fully coherent precoding matrices), and the fully coherent precoding matrix may be represented as:

[0223] In some embodiments, may be

[0224] In some embodiments, may be

[0225] In some embodiments, P can be 8 or 12 or 16. In some embodiments, l can be a non - negative integer. For example, 0 ≤ l ≤ O1N1. For another example, 0 ≤ l ≤ O1N1 / 2. For another example, l can be at least one of {0, 2, 4, 6, 8}. For another example, l can be at least one of {0, 1, 2, 3}. For another example, l can be 0 or 1. In some embodiments, m can be a non - negative integer. For example, 0 ≤ m ≤ O2N2. For another example, m can be at least one of {0, 2, 4, 6, 8}. For another example, m can be at least one of {0, 1, 2, 3}. For another example, m can be 0 or 1. For another example, m can be 0. In some embodiments, n can be a non - negative integer. For example, n can be at least one of {0, 1, 2, 3}. For another example, n can be 0 or 1. For another example, n can be 0 or 2. For another example, n can be 0. In some embodiments, l′ = l + O1. In some embodiments, l″ = l + 2O1. In some embodiments, m and m′ and m″ can be 0. In some embodiments, l′ = l + O1. In some embodiments, l″ = l + O1. In some embodiments, m′ = m. In some embodiments, m″ = m + O2.

[0226] In some embodiments, there can be more than one subset of precoding matrices corresponding to 5 layers. In some embodiments, the first group of precoding matrices corresponding to 5 layers can include more than one subset. For example, there can be two subsets of precoding matrices.

[0227] In some embodiments, there can be a first subset of precoding matrices corresponding to 5 layers, and for the first subset of precoding matrices, the value of "N1" can be 4, the value of "N2" can be 1, and the value of "O1" can be 4 or 2 or 1. For example, the value of "O2" can be 1. In some embodiments, for the first subset, In some embodiments, for the first subset, m and m′ and m″ can be 0. In some embodiments, for the first subset, l′ = l + O1, l″ = l + 2O1. In some embodiments, for the first subset, l can be a non - negative integer, 0 ≤ l ≤ O1N1. For example, l can be at least one of {0, 2, 4, 6}. For another example, l can be at least one of {0, 1, 2, 3}. For another example, l can be 0 or 1. For another example, l can be 0 or 2. In some embodiments, the number of precoding matrices in the first subset corresponding to 5 layers can be 32 or 16 or 8 or 4 or 2.

[0228] In some embodiments, there may be a second subset of precoding matrices corresponding to 5 layers, and corresponding to the second subset of precoding matrices, the value of "N1" may be 2, the value of "N2" may be 2, and the value of "O1" may be 4 or 2 or 1. For example, the value of "O2" may be 4 or 2 or 1. In some embodiments, corresponding to the second subset, In some embodiments, corresponding to the second subset, l′ = l + O1, l″ = l + O1. In some embodiments, corresponding to the second subset, m′ = m, m″ = m + O2. In some embodiments, corresponding to the second subset, l may be a non - negative integer, 0 ≤ l ≤ O1N1. For example, l may be at least one of {0, 2, 4, 6}. Also for example, l may be at least one of {0, 1, 2, 3}. Also for example, l may be 0 or 1. Also for example, l may be 0 or 2. In some embodiments, corresponding to the second subset, m may be a non - negative integer. For example, 0 ≤ m ≤ P2N2. Also for example, m may be at least one of {0, 2, 4, 6, 8}. Also for example, m may be at least one of {0, 1, 2, 3}. Also for example, m may be 0 or 1. Also for example, m may be 0. In some embodiments, the number of precoding matrices in the second subset corresponding to 5 layers may be 128 or 32 or 16 or 8 or 4 or 2.

[0229] In some embodiments, N1 may be equal to 4, N2 equal to 1, O1 may be equal to 2, and O2 may be equal to 1, and i 1,1 may be one of the following: {0, … N1O1 - 1} or {0, 2, 4, 6} or {0, 4} or {0, 1} or 0 or {0, … N1O1 / 2 - 1} or {0, 2}. Corresponding to the first subset of precoding matrices for 5 layers, for example, "Set_f5_1" may include 16 precoding matrices. In some embodiments, the first subset of precoding matrices "Set_f5_1" may include 8 precoding matrices. Alternatively, the first subset of precoding matrices "Set_f5_1" may include 4 precoding matrices. In other embodiments, the first subset of precoding matrices "Set_f5_1" may include 2 precoding matrices.

[0230] Alternatively, N1 may be equal to 2, N2 equal to 2, O1 may be equal to 1 or 4, and O2 may be equal to 2 or 4, i 1,1 or i 1,2It can be one of the following: {0, … 7} or {0, 2, 4, 6} or {0, 4} or {0, … 3} or {0, 2} or {0, 1} or 0. Corresponding to the second subset of precoding matrices for 5 layers, for example, “Set_f5_2” can include 128 precoding matrices. In some embodiments, the second subset of precoding matrices “Set_f5_2” can include 32 precoding matrices. Alternatively, the second subset of precoding matrices “Set_f5_2” can include 8 precoding matrices. In other embodiments, the second subset of precoding matrices “Set_f5_2” can include 2 precoding matrices.

[0231] In some embodiments, the terminal device 110 is indicated to have 5 layers, and there may be a second set of precoding matrices (e.g., a second set of partially coherent precoding matrices) corresponding to 5 layers. For example, if the terminal device 110 has 8 antenna ports, or if the PUSCH transmission of the terminal device 110 is associated with 8 antenna ports, or if the PUSCH transmission of the terminal device 110 is associated with an SRS having 8 ports, then 4 antenna ports (e.g., the first set of 4 ports) may be coherent, and the other 4 antenna ports (e.g., the second set of 4 ports) may be coherent. For example, the first set of 4 ports may be non - coherent with the second set of 4 ports. In some embodiments, there may be a second set of precoding matrices (e.g., a second set of partially coherent precoding matrices) corresponding to 5 layers, e.g., denoted as "Set_p5_1", and the size of the partially coherent precoding matrix may be 5 by 8 or 8 by 5. In some embodiments, the precoding matrix may have 5 columns or rows. In some embodiments, there may be 8 elements in a column or row of the precoding matrix. In some embodiments, for a column or row of the partially coherent precoding matrix, 4 out of the 8 elements in the partially coherent matrix may have non - zero values. And the other 4 elements in the partially coherent precoding matrix may have a value of 0. In some embodiments, there may be C1 columns or rows (e.g., the first set of C1 columns or rows. For example, C1 may be 1 or 2 or 3 or 4) in the 5 columns or rows of the precoding matrix, and in each column, the non - zero values may be mapped to 4 out of the 8 elements, and 0 for the other 4 elements. For example, in the first set of C1 columns or rows, the indices of the 4 elements with non - zero values may be the same. For example, the indices of the 4 elements with non - zero values may be idx_1, and idx_1 may be 4 values from {0,1,2,3,4,5,6,7} or {1,2,3,4,5,6,7,8}. In some embodiments, the 4 values of idx_1 may be based on the indices of the 4 antenna ports in the first set. For example, idx_1 may be {0,1,2,3} or {0,2,4,6} or {1,2,3,4} or {1,3,5,7}. In some embodiments, for the other 5 - C1 columns, 5 - C1 vectors of length 4 from the first set or the second set of vectors of length 4 may be selected. In some embodiments, for the other 5 - C1 columns or rows (e.g., the second set of 5 - C1 columns or rows) in the 5 columns or rows of the precoding matrix, in each column or row, the non - zero values may be mapped to 4 out of the 8 elements, and 0 may be mapped to the other 4 elements. For example, the indices of the 4 elements with non - zero values may be the same in the second set of 5 - C1 columns or rows. For example, the indices of the 4 elements with non - zero values may be idx_2, and idx_2 may be 4 values from {0,1,2,3,4,5,6,7} or {1,2,3,4,5,6,7,8}.In some embodiments, the 4 values of idx_2 can be based on the indices of 4 antenna ports in the second group. For example, idx_2 can be {4, 5, 6, 7} or {1, 3, 5, 7} or {5, 6, 7, 8} or {2, 4, 6, 8}. In some embodiments, any value of idx_1 can be different from any value of idx_2. In some embodiments, alternatively, 3 columns can be selected. In each column, non-zero values can be mapped to 4 of the 8 elements, and 0 can be mapped to the other 4 elements. For the other 2 columns, a matrix and 2 vectors can be selected.

[0232] In some embodiments, there can be two groups of vectors of length 4, and each group can include 4 vectors of length 4. In some embodiments, the values in the vectors of length 4 can be applied to the 4 non-zero values that are mapped to 4 elements in a column or a row of the precoding matrix. For example, the first group of vectors of length 4 can be {[1; 1; 1; 1], [1; -1; 1; -1], [1; 1; -1; -1], [1; -1; -1; 1]}. As another example, the second group of vectors of length 4 can be {[1; 1; j; j], [1; -1; j; -j], [1; 1; -j; -j], [1; -1; -j; j]}. In some embodiments, the 4 values in each vector in the first group or the second group can be mapped to 4 of the 8 elements, and 0 can be mapped to the other 4 elements in a column or a row of the precoding matrix.

[0233] In some embodiments, an example of the precoding matrix in the second group of precoding matrices corresponding to 5 layers can be as follows: or For example, rows or columns can be swapped. For example, rows or columns can be swapped. For example, each of [a1, a2, a3, a4], [b1, b2, b3, b4], [c1, c2, c3, c4], and [d1, d2, d3, d4] can be one of the vectors of length 4 in the first set of vectors of length 4 or the second set of vectors of length 4. For example, [e1, e2, e3, e4] can be one of the vectors of length 4 in the first set of vectors of length 4 or the second set of vectors of length 4. For example, [a1, a2, a3, a4], [b1, b2, b3, b4], [c1, c2, c3, c4], and [d1, d2, d3, d4] can be [1; 1; 1; 1], [1; -1; 1; -1], [1; 1; -1; -1], and [1; -1; -1; 1], respectively. Again, for example, [a1, a2, a3, a4], [b1, b2, b3, b4], [c1, c2, c3, c4], and [d1, d2, d3, d4] can be [1; 1; j; j], [1; -1; j; -j], [1; 1; -j; -j], and [1; -1; -j; j], respectively. For example, [e1, e2, e3, e4] can be one of the vectors [1; 1; 1; 1], [1; -1; 1; -1], [1; 1; -1; -1], and [1; -1; -1; 1]. Again, for example, [e1, e2, e3, e4] can be one of the vectors [1; 1; j; j], [1; -1; j; -j], [1; 1; -j; -j], and [1; -1; -j; j]. For example, each of [a1, a2, a3, a4], [b1, b2, b3, b4], [c1, c2, c3, c4] can be one of the vectors of length 4 in the first set of vectors of length 4 or the second set of vectors of length 4. For example, each of [d1, d2, d3, d4], [e1, e2, e3, e4] can be one of the vectors of length 4 in the first set of vectors of length 4 or the second set of vectors of length 4. For example, [a1, a2, a3, a4], [b1, b2, b3, b4], [c1, c2, c3, c4] can be three of the vectors [1; 1; 1; 1], [1; -1; 1; -1], [1; 1; -1; -1], and [1; -1; -1; 1]. Again, for example, [a1, a2, a3, a4], [b1, b2, b3, b4], [c1, c2, c3, c4] can be three of [1; 1; j; j], [1; -1; j; -j], [1; 1; -j; -j], and [1; -1; -j; j]. For example, [d1, d2, d3, d4], [e1, e2, e3, e4] can be two of the vectors [1; 1; 1; 1], [1; -1; 1; -1], [1; 1; -1; -1], and [1; -1; -1; 1].For another example, [d1, d2, d3, d4], [e1, e2, e3, e4] can be two vectors among [1; 1; j; j], [1; -1; j; -j], [1; 1; -j; -j], and [1; -1; -j; j].

[0234] In some embodiments, s5 can be a positive integer. For example, 1 ≤ s5 ≤ 64. For example, s5 can be 64 or 32 or 16 or 8 or 4 or 2 or 40 or 20 or 10.

[0235] In some embodiments, if the terminal device 110 is indicated to have 5 layers, there may be a third set of precoding matrices (e.g., the third set of partial interference precoding matrices) corresponding to 5 layers. For example, the structure of 8 ports can be 2+2+2+2, which means there are 4 groups, each group includes 2 antenna ports, and within each group, the 2 antenna ports can be coherent. For example, between groups, the antenna ports may not be coherent. In some embodiments, there may be a third set of precoding matrices (e.g., the third set of partial interference precoding matrices), such as denoted as "Set_p5_2", and the size of the precoding matrix can be 5 by 8 or 8 by 5. In some embodiments, the precoding matrix can have 5 columns or rows. In some embodiments, there can be 8 elements in a column or row of the precoding matrix. In some embodiments, for a column or row of the precoding matrix, 2 out of the 8 elements in the precoding matrix can have non-zero values. And the other 6 elements in the precoding matrix can have a value of 0. In some embodiments, there can be 2 columns or rows out of 5 columns or rows in the precoding matrix (e.g., the first set of 2 columns or rows), and in each column or row, the non-zero values can be mapped to 2 out of the 8 elements, and 0 can be mapped to the other 6 elements. For example, in the first set of 2 columns or rows, the indices of the 2 elements with non-zero values can be the same. For example, the indices of the 2 elements with non-zero values can be idx_1, and idx_1 can be 2 values from {0,1,2,3,4,5,6,7} or {1,2,3,4,5,6,7,8}. In some embodiments, the 2 values of idx_1 can be based on the indices of two antenna ports out of the 4 antenna ports in the first group. In some embodiments, the 2 values of idx_1 can be based on the indices of 2 antenna ports in the third group. For example, idx_1 can be {0,1} or {0,2} or {1,2} or {1,3} or {0,4} or {1,5}. In some embodiments, there can be 1 or 2 columns or rows out of 5 columns or rows in the precoding matrix (e.g., the second set of 1 or 2 columns or rows), and in each column or row, the non-zero values can be mapped to 2 out of the 8 elements, and 0 can be mapped to the other 6 elements. For example, in the second set of 1 or 2 columns or rows, the indices of the 2 elements with non-zero values can be the same. For example, the indices of the 2 elements with non-zero values can be idx_2, and idx_2 can be 2 values from {0,1,2,3,4,5,6,7} or {1,2,3,4,5,6,7,8}. In some embodiments, the 2 values of idx_2 can be based on the indices of the remaining two antenna ports out of the 4 antenna ports in the first group. In some embodiments, the 2 values of idx_2 can be based on the indices of 2 antenna ports in the fourth group. For example, idx_2 can be {2,3} or {1,3} or {3,4} or {2,4} or {1,5} or {2,6}.In some embodiments, there may be 1 or 2 columns or rows out of 5 columns or rows in the precoding matrix (e.g., the third group of 1 or 2 columns or rows), and in each column or row, non-zero values may be mapped to 2 elements out of 8 elements, and 0 may be mapped to the other 6 elements. For example, in the third group of 1 or 2 columns or rows, the indices of the 2 elements with non-zero values may be the same. For example, the indices of the 2 elements with non-zero values may be idx_3, and idx_3 may be 2 values from {0, 1, 2, 3, 4, 5, 6, 7} or {1, 2, 3, 4, 5, 6, 7, 8}. In some embodiments, the 2 values of idx_3 may be based on the indices of two antenna ports out of the 4 antenna ports in the second group. In some embodiments, the 2 values of idx_3 may be based on the indices of 2 antenna ports in the fifth group. For example, idx_3 may be {4, 5} or {4, 6} or {5, 6} or {5, 7} or {2, 6} or {3, 7}. In some embodiments, there may be 1 or 2 columns or rows out of 5 columns or rows in the precoding matrix (e.g., the fourth group of 1 or 2 columns or rows), and in each column or row, non-zero values may be mapped to 2 elements out of 8 elements, and 0 may be mapped to the other 6 elements. For example, in the fourth group of 1 or 2 columns or rows, the indices of the 2 elements with non-zero values may be the same. For example, the indices of the 2 elements with non-zero values may be idx_4, and idx_4 may be 2 values from {0, 1, 2, 3, 4, 5, 6, 7} or {1, 2, 3, 4, 5, 6, 7, 8}. In some embodiments, the 2 values of idx_4 may be based on the indices of the remaining two antenna ports out of the 4 antenna ports in the second group. In some embodiments, the 2 values of idx_4 may be based on the indices of 2 antenna ports in the sixth group. For example, idx_4 may be {6, 7} or {5, 7} or {7, 8} or {6, 8} or {3, 7} or {4, 8}. In some embodiments, any value of idx_1, any value of idx_2, any value of idx_3, and any value of idx_4 may be different from each other. In some embodiments, the total number of columns or rows in the first group and / or the second group and / or the third group and / or the fourth group may be 5. In some embodiments, there may be a first group, a second group, and a third group, and each of two of the three groups has 2 columns or rows, and one of the three groups has 1 column or row. In some embodiments, there may be a first group, a second group, a third group, and a fourth group, and one of the four groups has 2 columns or rows, and each of the other three groups in the fourth group has 1 column or row.

[0236] In some embodiments, there may be a set of 4 vectors of length 2, and each of the vectors of length 2 can be applied as two non-zero values in a column or a row of a precoding matrix. In some embodiments, for a third set of precoding matrices corresponding to 5 layers, such as Set_p5_2, two vectors of length 2 can be selected from the 4 vectors of length 2, and the 2 values in each vector can be mapped to 2 of the 8 elements, and 0 can be mapped to the other elements in a column or a row of the precoding matrix. In some embodiments, there may be two sets of vectors of length 2, and each set may include 2 vectors of length 2. In some embodiments, the two values in a vector of length 2 can be applied as two non-zero values mapped to 2 elements in a column or a row of the precoding matrix. For example, the first set of vectors of length 2 can be {[1; 1], [1; -1]}. As another example, the second set of vectors of length 2 can be {[1; j], [1; -j]}. In some embodiments, the 2 values in each vector in the first set or the second set can be mapped to 2 of the 8 elements, and 0 can be mapped to the other 6 elements in a column or a row of the precoding matrix.

[0237] In some embodiments, for the first set of 2 columns or rows and / or for the second set of 1 or 2 columns or rows and / or for the third set of 1 or 2 columns or rows and / or for the fourth set of 1 or 2 columns or rows, the two vectors of two non-zero values selected to be mapped to 2 of the 8 elements in each column or row can be {[1; 1] and [1; -1]} or {[1; j] and [1; -j]}.

[0238] In some embodiments, an example of a precoding matrix in the third set of precoding matrices corresponding to 5 layers can be as follows: or For example, rows or columns can be swapped. For example, each of [a1, a2] and [b1, b2] can be one of the vectors of length 2 in the first set of vectors of length 2 or the second set of vectors of length 2. For example, each of [c1, c2] and [d1, d2] can be one of the vectors of length 2 in the first set of vectors of length 2 or the second set of vectors of length 2. For example, [e1, e2] can be one of the vectors of length 2 in the first set of vectors of length 2 or the second set of vectors of length 2. For example, [a1, a2] and [b1, b2] can be [1; 1] and [1; -1] respectively. As another example, [a1, a2] and [b1, b2] can be [1; j] and [1; -j] respectively. For example, [c1, c2] and [d1, d2] can be [1; 1] and [1; -1] respectively. As another example, [c1, c2] and [d1, d2] can be [1; j] and [1; -j] respectively. For example, [c1, c2], [d1, d2], and [e1, e2] can be any one of [1; 1], [1; -1], [1; j], and [1; -j].

[0239] In some embodiments, if the terminal device 110 is indicated to have 5 layers, there may be a fourth set of precoding matrices corresponding to 5 layers (e.g., a fourth set of non-coherent precoding matrices). For example, each of the 8 antenna ports may be non-coherent with each other. In some embodiments, there may be a fourth set of precoding matrices (e.g., a fourth set of non-coherent precoding matrices), such as denoted as "Set_n5_1", and the size of the precoding matrix may be 5 by 8 or 8 by 5. In some embodiments, the precoding matrix may have 5 columns or rows. In some embodiments, there may be 8 elements in a column or row of the precoding matrix. In some embodiments, for a column or row of the precoding matrix, 1 element out of the 8 elements in the precoding matrix may have a non-zero value. For example, the non-zero value may be 1. And the other 7 elements in the precoding matrix may have a value of 0. In some embodiments, for each column or row of the 5 columns or rows in the precoding matrix, the non-zero value may be mapped to 1 element out of the 8 elements, and 0 may be mapped to the other 7 elements. For example, in each row or column of the precoding matrix, the indices of the elements with non-zero values may be different. For example, the index of the 1 element with a non-zero value may be idx_1, idx_2, idx_3, idx_4, idx_5 respectively for the first, second, third, fourth, fifth columns or rows of the precoding matrix, and for each of idx_1, idx_2, idx_3, idx_4, idx_5, the value may be 1 value out of {0, 1, 2, 3, 4, 5, 6, 7} or {1, 2, 3, 4, 5, 6, 7, 8}. For example, the values of idx_1, idx_2, idx_3, idx_4, idx_5 may be 0, 1, 2, 3, 4 respectively. As another example, the values of idx_1, idx_2, idx_3, idx_4, idx_5 may be 1, 2, 3, 4, 5 respectively. For example, the values of idx_1, idx_2, idx_3, idx_4, idx_5 may be different from each other.

[0240] In some embodiments, if the terminal device 110 is indicated to have 5 layers, there may be a fourth set of precoding matrices corresponding to 5 layers. For example, there may be only one precoding matrix (e.g., a non-coherent precoding matrix) in the fourth set corresponding to 6 layers.

[0241] In some embodiments, if there are 5 layers at the terminal device 110, a hybrid partial coherence matrix may be supported. For example, the antenna structure may be 4+2+2, which means 4 antenna ports may be coherent, 2 antenna ports may be coherent, and the other 2 antenna ports may be coherent. In this case, r1 (e.g., 1, 2, 3, or 4) columns may be mapped with vectors of length 4, and 5 - r1 columns may be mapped with vectors of length 2, and port swapping.

[0242] In other embodiments, the antenna structure can be 4+1+1+1+1, which means that 4 antenna ports can be coherent. In this case, r1 (e.g., 1 or 2 or 3 or 4) columns can have vectors of length 4, 5-r1 columns can have 1 on one element, and the rows can be swapped.

[0243] In some embodiments, the antenna structure can be 4+2+1+1, which means that 4 antenna ports can be coherent and 2 antenna ports can be coherent. For example, r1 (e.g., 1 or 2 or 3 or 4) columns can have vectors of length 4, and r2 (e.g., 0, 1, 2) columns can have vectors of length 2, and 5-r1-r2 columns can have 1 on one element.

[0244] In other embodiments, the antenna structure can be 2+2+1+1+1+1, which means that 2 antenna ports can be coherent and 2 antenna ports can be coherent. For example, r1 (e.g., 1 or 2 or 3 or 4) columns can have vectors of length 2, and 5-r1 columns can have 1 on one element.

[0245] In some embodiments, the terminal device 110 is indicated to have 4 layers, and there can be a first set of precoding matrices (e.g., the first set of fully coherent precoding matrices) corresponding to 4 layers. In some embodiments, the fully coherent precoding matrices can be represented as:

[0246] In some embodiments, can be

[0247] In some embodiments, P can be 8 or 12 or 16. In some embodiments, l can be a non-negative integer. For example, 0 ≤ l ≤ O1N1. For another example, 0 ≤ l ≤ O1N1 / 2. For another example, l can be at least one of {0, 2, 4, 6, 8}. For another example, l can be at least one of {0, 1, 2, 3}. For another example, l can be 0 or 1. In some embodiments, m can be a non-negative integer. For example, 0 ≤ m ≤ O2N2. For another example, m can be at least one of {0, 2, 4, 6, 8}. For another example, m can be at least one of {0, 1, 2, 3}. For another example, m can be 0 or 1. For another example, m can be 0. In some embodiments, n can be a non-negative integer. For example, n can be at least one of {0, 1, 2, 3}. For another example, n can be 0 or 1. For another example, n can be 0 or 2. For another example, n can be 0. In some embodiments, l′ = l + k1. In some embodiments, m′ = m + k2. In some embodiments, k1 can be a non-negative integer. For example, k1 can be at least one of {0, O1, 2O1, 3O1}. For another example, k1 can be 0. In some embodiments, k2 can be a non-negative integer. For example, k2 can be at least one of {0, O2}. In some embodiments, k2 can be 0.

[0248] In some embodiments, there can be a parameter i 1,3 , and the values of k1 and / or k2 can be based on the value of i 1,3 , and i 1,3 can be a non-negative integer. For example, i 1,3 can be at least one of {0, 1, 2, 3}. For another example, i 1,3 can be 0 or 1. For another example, i 1,3 can be 0. In some embodiments, when N1 = 4 and N2 = 1, and when i 1,3 = 0, k1 = 0 and / or k2 = 0. In some embodiments, when N1 = 4 and N2 = 1, and when i 1,3 = 1, k1 = O1 and / or k2 = 0. In some embodiments, when N1 = 4 and N2 = 1, and when i 1,3 = 2, k1 = 2O1 and / or k2 = 0. In some embodiments, when N1 = 4 and N2 = 1, and when i 1,3 = 3, k1 = 3O1 and / or k2 = 0. In some embodiments, when N1 = 2 and N2 = 2, and when i 1,3 = 0, k1 = 0 and / or k2 = 0. In some embodiments, when N1 = 2 and N2 = 2, and when i 1,3 = 1, k1 = O1 and / or k2 = 0.

[0249] In some embodiments, there may be more than one subset of precoding matrices corresponding to 4 layers. In some embodiments, the first set of precoding matrices corresponding to 4 layers may include more than one subset. For example, there may be two or three or four subsets of precoding matrices.

[0250] In some embodiments, there may be a first subset of precoding matrices corresponding to 4 layers, and corresponding to the first subset of precoding matrices, the value of "N1" may be 4, the value of "N2" may be 1, and the value of "O1" may be 4 or 2 or 1. For example, the value of "O2" may be 1. In some embodiments, corresponding to the first subset, In some embodiments, corresponding to the first subset, m and m' may be 0. In some embodiments, corresponding to the first subset, l' = l + k1. In some embodiments, corresponding to the first subset, l may be a non - negative integer, 0 ≤ l ≤ O1N1. For example, l may be at least one of {0, 2, 4, 6}. Again, for example, l may be at least one of {0, 1, 2, 3}. Again, for example, l may be 0 or 1. Again, for example, l may be 0 or 2. In some embodiments, the number of precoding matrices in the first subset corresponding to 4 layers may be 128 or 64 or 32 or 16 or 8 or 4 or 2.

[0251] In some embodiments, there may be a second subset of precoding matrices corresponding to 4 layers, and corresponding to the second subset of precoding matrices, the value of "N1" may be 2, the value of "N2" may be 2, and the value of "O1" may be 4 or 2 or 1. For example, the value of "O2" may be 4 or 2 or 1. In some embodiments, corresponding to the second subset, In some embodiments, corresponding to the second subset, l' = l + k1. In some embodiments, corresponding to the second subset, m' = m + k2. In some embodiments, corresponding to the second subset, l may be a non - negative integer, 0 ≤ l ≤ O1N1. For example, l may be at least one of {0, 2, 4, 6}. Again, for example, l may be at least one of {0, 1, 2, 3}. Again, for example, l may be 0 or 1. Again, for example, l may be 0 or 2. In some embodiments, corresponding to the second subset, m may be a non - negative integer. For example, 0 ≤ m ≤ O2N2. Again, for example, m may be at least one of {0, 2, 4, 6}. Again, for example, m may be at least one of {0, 1, 2, 3}. Again, for example, m may be 0 or 1. Again, for example, m may be 0. In some embodiments, the number of precoding matrices in the second subset corresponding to 4 layers may be 256 or 128 or 32 or 16 or 8 or 4 or 2.

[0252] In some embodiments, N1 can be equal to 4, N2 is equal to 1, O1 can be equal to 4 or 2 or 1, and O2 can be equal to 1, and i 1,1 can be one of the following: {0, … N1O1 - 1} or {0, 2, 4, 6} or {0, 4} or {0, 1} or 0 or {0, … N1O1 / 2 - 1} or {0, 2}. Corresponding to the first subset of precoding matrices for 4 layers, for example, “Set_f4_1” can include 16 precoding matrices. In some embodiments, the first subset of precoding matrices “Set_f4_1” can include 8 precoding matrices. Alternatively, the first subset of precoding matrices “Set_f4_1” can include 4 precoding matrices. In other embodiments, the first subset of precoding matrices “Set_f4_1” can include 2 precoding matrices.

[0253] Alternatively, N1 can be equal to 2, N2 can be equal to 2, O1 can be equal to 1 or 2 or 4, and O2 can be equal to 1 or 2 or 4, i 1,3 can be 0 or 1 or 2 or 3, i 1,1 or i 1,2 can be one of the following: {0, … 3} or {0, 2} or 0. In some embodiments, the second subset of precoding matrices corresponding to 4 layers, for example, “Set_f4_2” can include 32 precoding matrices. Alternatively, the second subset of precoding matrices “Set_f4_2” can include 8 precoding matrices. In other embodiments, the second subset of precoding matrices “Set_f4_2” can include 2 precoding matrices.

[0254] In some embodiments, there can be a second factor a p . In some embodiments, In some embodiments, p can be a non - negative integer. For example, p can be at least one of {0, 1, 2, 3}. Again, for example, p can be 0 or 1. Again, for example, p can be 0 or 2. Again, for example, p can be 0.

[0255] In some embodiments, if the terminal device 110 is indicated to have 4 layers, there can be a third subset or a fourth subset of precoding matrices. In some embodiments, there can be a third factor b nb . In some embodiments, In some embodiments, n_b can be a non - negative integer. For example, n_b can be at least one of {0, 1, 2, 3}. Again, for example, n_b can be 0 or 1. Again, for example, n_b can be 0 or 2. Again, for example, n_b can be 0.

[0256] In some embodiments, there can be a third vector In some embodiments, In some embodiments, there may be a fourth vector In some embodiments, In some embodiments, N1 = 2 and In some embodiments, l may be a non - negative integer. For example, 0 ≤ l ≤ O1N1. For another example, l may be at least one of {0, 2}. For another example, l may be at least one of {0, 1, 2, 3}. For another example, l may be 0 or 1. In some embodiments, the value of p1 may be at least one of {0, 1, 2, 3} or {0, 1} or {0, 2}. In some embodiments, the value of p1 may be 0. In some embodiments, the value of n may be at least one of {0, 1, 2, 3} or {0, 1} or {0, 2}. In some embodiments, the value of n may be 0.

[0257] In some embodiments, there may be a parameter i 1,3 , and the values of k1 and / or k2 may be based on the value of i 1,3 value, and i 1,3 may be a non - negative integer. For example, i 1,3 may be at least one of {0, 1}. For another example, i 1,3 may be 0. In some embodiments, in the case of N1 = 2 and N2 = 1, and in the case of i 1,3 = 0, k1 = O1 and / or k2 = 0.

[0258] In some embodiments, there may be a third subset of precoding matrices corresponding to 4 layers, and corresponding to the third subset of precoding matrices, the value of "N1" may be 2, the value of "N2" may be 1, and the value of "O1" may be 4 or 2 or 1. For example, the value of "O2" may be 1. In some embodiments, corresponding to the third subset, In some embodiments, corresponding to the third subset, m and m′ may be 0. In some embodiments, corresponding to the third subset, l′ = l + k1. In some embodiments, corresponding to the third subset, l may be a non - negative integer, 0 ≤ l ≤ O1N1. For example, l may be at least one of {0, 1, 2, 3}. For another example, l may be 0 or 1. For another example, l may be 0 or 2. In some embodiments, the number of precoding matrices in the third subset corresponding to 4 layers may be 64 or 32 or 16 or 8 or 4 or 2. In some embodiments, the terminal device 110 may be indicated to have 4 layers, and the precoding matrices in the third subset corresponding to 4 layers may be represented as: In some embodiments, may be In some embodiments, corresponding to the third subset, l′ = l + k1. In some embodiments, k1 can be O1 or 0. In some embodiments, corresponding to the third subset, m′ = m + k2. In some embodiments, k2 can be 0. In some embodiments, p can be p1.

[0259] In some embodiments, there may be a fifth vector In some embodiments, In some embodiments, there may be a sixth vector In some embodiments, In some embodiments, N1 = 2 and In some embodiments, l can be a non - negative integer. For example, 0 ≤ l ≤ O1N1. Again, for example, l can be at least one of {0, 2}. Again, for example, l can be at least one of {0, 1, 2, 3}. Again, for example, l can be 0 or 1. In some embodiments, the value of p1 can be at least one of {0, 1, 2, 3} or {0, 1} or {0, 2}. In some embodiments, the value of p1 can be 0. In some embodiments, the value of n0 can be at least one of {0, 1, 2, 3} or {0, 1} or {0, 2}. In some embodiments, the value of n0 can be 0. In some embodiments, the value of n1 can be at least one of {0, 1, 2, 3} or {0, 1} or {0, 2}. In some embodiments, the value of n1 can be 0. In some embodiments, the value of n2 can be at least one of {0, 1, 2, 3} or {0, 1} or {0, 2}. In some embodiments, the value of n2 can be 0. In some embodiments, l′ = l + k1. In some embodiments, k1 can be O1 or 0. In some embodiments, m′ = m + k2. In some embodiments, k2 can be 0. In some embodiments, m and m′ can be 0.

[0260] In some embodiments, there may be a fourth subset of precoding matrices corresponding to 4 - layer, and corresponding to the fourth subset of precoding matrices, the value of "N1" can be 2, the value of "N2" can be 1, and the value of "O1" can be 4 or 2 or 1. For example, the value of "O2" can be 1. In some embodiments, corresponding to the fourth subset, In some embodiments, corresponding to the fourth subset, m and m′ can be 0. In some embodiments, corresponding to the fourth subset, l′ = l + k1. In some embodiments, corresponding to the fourth subset, l can be a non - negative integer, 0 ≤ l ≤ O1N1. For example, l can be at least one of {0, 1, 2, 3}. Also for example, l can be 0 or 1. Also for example, l can be 0 or 2. In some embodiments, the number of precoding matrices in the fourth subset corresponding to 4 layers can be 64 or 32 or 16 or 8 or 4 or 2. In some embodiments, the terminal device 110 can be indicated to have 4 layers, and the precoding matrices in the fourth subset of precoding matrices corresponding to 4 layers can be expressed as: In some embodiments, can be In some embodiments, corresponding to the fourth subset, l′ = l + k1. In some embodiments, k1 can be O1 or 0. In some embodiments, corresponding to the fourth subset, m′ = m + k2. In some embodiments, k2 can be 0. In some embodiments, corresponding to the fourth subset, l′ = l + k1. In some embodiments, k1 can be O1 or 0. In some embodiments, corresponding to the fourth subset, m′ = m + k2. In some embodiments, k2 can be 0. In some embodiments, m and m′ can be 0. In some embodiments, p can be [p1p2]. In some embodiments, n can be [n0n1n2].

[0261] In some embodiments, if the terminal device 110 is indicated to have 4 layers, there may be a second set of precoding matrices corresponding to 4 layers (e.g., a second set of partially coherent precoding matrices). For example, if the terminal device 110 has 8 antenna ports, or if the PUSCH transmission of the terminal device 110 is associated with 8 antenna ports, or if the PUSCH transmission of the terminal device 110 is associated with an SRS having 8 ports, then 4 antenna ports (e.g., the first set of 4 ports) may be coherent, and the other 4 antenna ports (e.g., the second set of 4 ports) may be coherent. For example, the first set of 4 ports may be non - coherent with the second set of 4 ports. In some embodiments, there may be a second set of precoding matrices corresponding to 4 layers (e.g., a second set of partially coherent precoding matrices), for example, denoted as "Set_p4_1", and the size of the partially coherent precoding matrix may be 4 by 8 or 8 by 4. In some embodiments, the precoding matrix may have 4 columns or rows. In some embodiments, there may be 8 elements in a column or row of the precoding matrix. In some embodiments, for a column or row of the partially coherent precoding matrix, 4 of the 8 elements in the partially coherent matrix may have non - zero values. And the other 4 elements in the partially coherent precoding matrix may have a value of 0. In some embodiments, there may be C2 columns or rows (e.g., the first set of C2 columns or rows. For example, C2 may be 1 or 2 or 3 or 4) in the 4 columns or rows of the precoding matrix, and in each column, the non - zero values may be mapped to 4 of the 8 elements, and 0 for the other 4 elements. For example, in the first set of C2 columns or rows, the indices of the 4 elements with non - zero values may be the same. For example, the indices of the 4 elements with non - zero values may be idx_1, and idx_1 may be 4 values from {0, 1, 2, 3, 4, 5, 6, 7} or {1, 2, 3, 4, 5, 6, 7, 8}. In some embodiments, the 4 values of idx_1 may be based on the indices of the 4 antenna ports in the first set. For example, idx_1 may be {0, 1, 2, 3} or {0, 2, 4, 6} or {1, 2, 3, 4} or {1, 3, 5, 7}. In some embodiments, for the other 4 - C2 columns, 4 - C2 vectors of length 4 from the first set of vectors of length 4 or the second set of vectors of length 4 may be selected. In some embodiments, for the other 4 - C2 columns or rows (e.g., the second set of 4 - C2 columns or rows) in the 4 columns or rows of the precoding matrix, in each column or row, the non - zero values may be mapped to 4 of the 8 elements, and 0 may be mapped to the other 4 elements. For example, in the second set of 4 - C2 columns or rows, the indices of the 4 elements with non - zero values may be the same. For example, the indices of the 4 elements with non - zero values may be idx_2, and idx_2 may be 4 values from {0, 1, 2, 3, 4, 5, 6, 7} or {1, 2, 3, 4, 5, 6, 7, 8}.In some embodiments, the 4 values of idx_2 can be based on the indices of 4 antenna ports in the second group. For example, idx_2 can be {4, 5, 6, 7} or {1, 3, 5, 7} or {5, 6, 7, 8} or {2, 4, 6, 8}. In some embodiments, any value of idx_1 can be different from any value of idx_2. In some embodiments, C2 can be 4, and there may be no second group of columns or rows.

[0262] In some embodiments, there can be two groups of vectors of length 4, and each group can include 4 vectors of length 4. In some embodiments, the values in the vectors of length 4 can be applied to map to 4 non-zero values of 4 elements in the columns or rows of the precoding matrix. For example, the first group of vectors of length 4 can be {[1; 1; 1; 1], [1; -1; 1; -1], [1; 1; -1; -1], [1; -1; -1; 1]}. As another example, the second group of vectors of length 4 can be {[1; 1; j; j], [1; -1; j; -j], [1; 1; -j; -j], [1; -1; -j; j]}. In some embodiments, the 4 values in each vector in the first group or the second group can be mapped to 4 of the 8 elements, and 0 can be mapped to the other 4 elements in the columns or rows of the precoding matrix. In some embodiments, an example of the precoding matrix in the second group of precoding matrices corresponding to 4 layers can be as follows: or or or For example, rows or columns can be swapped. For example, rows or columns can be swapped. For example, each of [a1, a2, a3, a4], [b1, b2, b3, b4], [c1, c2, c3, c4], and [d1, d2, d3, d4] can be one of the vectors of length 4 in the first group of vectors of length 4 or the second group of vectors of length 4. For example, [a1, a2, a3, a4], [b1, b2, b3, b4], [c1, c2, c3, c4], and [d1, d2, d3, d4] can be [1; 1; 1; 1], [1; -1; 1; -1], [1; 1; -1; -1], and [1; -1; -1; 1], respectively. As another example, [a1, a2, a3, a4], [b1, b2, b3, b4], [c1, c2, c3, c4], and [d1, d2, d3, d4] can be [1; 1; j; j], [1; -1; j; -j], [1; 1; -j; -j], and [1; -1; -j; j], respectively. For example, each of [a1, a2, a3, a4], [b1, b2, b3, b4], [c1, c2, c3, c4] can be one of the vectors of length 4 in the first group of vectors of length 4 or the second group of vectors of length 4. For example, [d1, d2, d3, d4] can be one of the vectors of length 4 in the first group of vectors of length 4 or the second group of vectors of length 4. For example, [a1, a2, a3, a4], [b1, b2, b3, b4] can be two of the vectors among [1; 1; 1; 1], [1; -1; 1; -1], [1; 1; -1; -1], and [1; -1; -1; 1]. As another example, [a1, a2, a3, a4], [b1, b2, b3, b4] can be two of [1; 1; j; j], [1; -1; j; -j], [1; 1; -j; -j], and [1; -1; -j; j]. For example, [c1, c2, c3, c4], [d1, d2, d3, d4] can be 2 of the vectors among [1; 1; 1; 1], [1; -1; 1; -1], [1; 1; -1; -1], and [1; -1; -1; 1]. As another example, [c1, c2, c3, c4], [d1, d2, d3, d4] can be 2 of the vectors among [1; 1; j; j], [1; -1; j; -j], [1; 1; -j; -j], and [1; -1; -j; j].

[0263] In some embodiments, s4 can be a positive integer. For example, 1 ≤ s4 ≤ 64. For example, s4 can be 64 or 32 or 16 or 8 or 4 or 2 or 32 or 16 or 8.

[0264] In some embodiments, N g can be equal to 2, N1 can be equal to 2, N2 is equal to 1, O1 can be equal to 2 or 4, i1,3 can be 0, and i 1,1 can be one of the following: {0, ··· N1O1 - 1} or {0, 2, 4, 6} or {0, 4} or {0, 2} or {0, 1} or 0, or i 1,4,1 can be one of the following: {0, 1, 2, 3} or {0, 2} or 0. In some embodiments, for the third subset of precoding matrices corresponding to 4 layers, e.g., "Set_f4_3" can include 64 precoding matrices. In some embodiments, the third subset "Set_f4_3" of precoding matrices can include 32 precoding matrices. The third subset "Set_f4_3" of precoding matrices can include 16 precoding matrices. In some embodiments, the third subset "Set_f4_3" of precoding matrices can include 8 precoding matrices. Alternatively, the third subset "Set_f4_3" of precoding matrices can include 4 precoding matrices. In other embodiments, the third subset "Set_f4_3" of precoding matrices can include 2 precoding matrices.

[0265] In some embodiments, N g can be equal to 2, N1 can be equal to 2, N2 equal to 1, O1 can be equal to 2 or 4, i 1,3 can be 0, and i 1,1 can be one of the following: {0, ··· N1O1 - 1} or {0, 2, 4, 6} or {0, 4} or {0, 2} or {0, 1} or 0, or i 1,4,q can be one of the following: {0, 1, 2, 3} or {0, 2} or 0, where q can be 0 or 1. In some embodiments, for the fourth subset of precoding matrices corresponding to 4 layers, e.g., "Set_f4_4" can include 256 precoding matrices. In some embodiments, the fourth subset "Set_f4_4" of precoding matrices can include 128 precoding matrices. In some embodiments, the fourth subset "Set_f4_4" of precoding matrices can include 64 precoding matrices. In some embodiments, the fourth subset "Set_f4_4" of precoding matrices can include 32 precoding matrices. The fourth subset "Set_f4_4" of precoding matrices can include 16 precoding matrices. In some embodiments, the fourth subset "Set_f4_4" of precoding matrices can include 8 precoding matrices. Alternatively, the fourth subset "Set_f4_4" of precoding matrices can include 4 precoding matrices. In other embodiments, the fourth subset "Set_f4_4" of precoding matrices can include 2 precoding matrices.

[0266] In some embodiments, if the terminal device 110 is indicated to have 4 layers, there may be a third set of precoding matrices (e.g., the third set of partial interference precoding matrices) corresponding to 4 layers. For example, the structure of 8 ports can be 2+2+2+2, which means there are 4 groups, each group including 2 antenna ports, and within each group, the 2 antenna ports can be coherent. For example, between groups, the antenna ports may not be coherent. In some embodiments, there may be a third set of precoding matrices (e.g., the third set of partial interference precoding matrices), such as denoted as "Set_p4_2", and the size of the precoding matrix can be 4 by 8 or 8 by 4. In some embodiments, the precoding matrix can have 4 columns or rows. In some embodiments, there can be 8 elements in the columns or rows of the precoding matrix. In some embodiments, for the columns or rows of the precoding matrix, 2 of the 8 elements in the precoding matrix can have non-zero values. And the other 6 elements in the precoding matrix can have the value 0. In some embodiments, there can be 1 or 2 columns or rows out of 4 columns or rows in the precoding matrix (e.g., the first set of 1 or 2 columns or rows), and in each column or row, the non-zero values can be mapped to 2 of the 8 elements, and 0 can be mapped to the other 6 elements. For example, in the first set of 1 or 2 columns or rows, the indices of the 2 elements with non-zero values can be the same. For example, the indices of the 2 elements with non-zero values can be idx_1, and idx_1 can be 2 values from {0,1,2,3,4,5,6,7} or {1,2,3,4,5,6,7,8}. In some embodiments, the 2 values of idx_1 can be based on the indices of two antenna ports out of the 4 antenna ports in the first group. In some embodiments, the 2 values of idx_1 can be based on the indices of 2 antenna ports in the third group. For example, idx_1 can be {0,1} or {0,2} or {1,2} or {1,3} or {0,4} or {1,5}. In some embodiments, there can be 1 or 2 columns or rows out of 4 columns or rows in the precoding matrix (e.g., the second set of 1 or 2 columns or rows), and in each column or row, the non-zero values can be mapped to 2 of the 8 elements, and 0 can be mapped to the other 6 elements. For example, in the second set of 1 or 2 columns or rows, the indices of the 2 elements with non-zero values can be the same. For example, the indices of the 2 elements with non-zero values can be idx_2, and idx_2 can be 2 values from {0,1,2,3,4,5,6,7} or {1,2,3,4,5,6,7,8}. In some embodiments, the 2 values of idx_2 can be based on the indices of the remaining two antenna ports out of the 4 antenna ports in the first group. In some embodiments, the 2 values of idx_2 can be based on the indices of 2 antenna ports in the fourth group. For example, idx_2 can be {2,3} or {1,3} or {3,4} or {2,4} or {1,5} or {2,6}.In some embodiments, there may be 1 or 2 columns or rows out of 4 columns or rows in the precoding matrix (e.g., the third group of 1 or 2 columns or rows), and in each column or row, non-zero values may be mapped to 2 out of 8 elements, and 0 may be mapped to the other 6 elements. For example, in the third group of 1 or 2 columns or rows, the indices of the 2 elements with non-zero values may be the same. For example, the indices of the 2 elements with non-zero values may be idx_3, and idx_3 may be 2 values from {0, 1, 2, 3, 4, 5, 6, 7} or {1, 2, 3, 4, 5, 6, 7, 8}. In some embodiments, the 2 values of idx_3 may be based on the indices of two antenna ports out of the 4 antenna ports in the second group. In some embodiments, the 2 values of idx_3 may be based on the indices of 2 antenna ports in the fifth group. For example, idx_3 may be {4, 5} or {4, 6} or {5, 6} or {5, 7} or {2, 6} or {3, 7}. In some embodiments, there may be 1 or 2 columns or rows out of 4 columns or rows in the precoding matrix (e.g., the fourth group of 1 or 2 columns or rows), and in each column or row, non-zero values may be mapped to 2 out of 8 elements, and 0 may be mapped to the other 6 elements. For example, in the fourth group of 1 or 2 columns or rows, the indices of the 2 elements with non-zero values may be the same. For example, the indices of the 2 elements with non-zero values may be idx_4, and idx_4 may be 2 values from {0, 1, 2, 3, 4, 5, 6, 7} or {1, 2, 3, 4, 5, 6, 7, 8}. In some embodiments, the 2 values of idx_4 may be based on the indices of the remaining two antenna ports out of the 4 antenna ports in the second group. In some embodiments, the 2 values of idx_4 may be based on the indices of 2 antenna ports in the sixth group. For example, idx_4 may be {6, 7} or {5, 7} or {7, 8} or {6, 8} or {3, 7} or {4, 8}. In some embodiments, any value of idx_1, any value of idx_2, any value of idx_3, and any value of idx_4 may be different from each other. In some embodiments, the total number of columns or rows in the first group and / or the second group and / or the third group and / or the fourth group may be 4. In some embodiments, there may be a first group and a second group, and each group has 2 columns or rows. In some embodiments, there may be a first group, a second group, and a third group, and each of two of the three groups has 2 columns or rows, and one of the three groups has 1 column or row. In some embodiments, there may be a first group, a second group, a third group, and a fourth group, and each group has 1 column or row.

[0267] In some embodiments, there may be a set of 4 vectors of length 2, and each of the vectors of length 2 can be applied as two non-zero values in a column or a row of a precoding matrix. In some embodiments, for a third set of precoding matrices corresponding to 4 layers, such as Set_p4_2, two vectors of length 2 can be selected from the 4 vectors of length 2, and the 2 values in each vector can be mapped to 2 of the 8 elements, and 0 can be mapped to the other elements in a column or a row of the precoding matrix. In some embodiments, there may be two sets of vectors of length 2, and each set may include 2 vectors of length 2. In some embodiments, the two values in a vector of length 2 can be applied as two non-zero values mapped to 2 elements in a column or a row of the precoding matrix. For example, the first set of vectors of length 2 can be {[1; 1], [1; -1]}. For another example, the second set of vectors of length 2 can be {[1; j], [1; -j]}. In some embodiments, the 2 values in each vector in the first set or the second set can be mapped to 2 of the 8 elements, and 0 can be mapped to the other 6 elements in a column or a row of the precoding matrix. In some embodiments, for the first set of 2 columns or rows and / or for the second set of 1 or 2 columns or rows and / or for the third set of 1 or 2 columns or rows and / or for the fourth set of 1 or 2 columns or rows, the two vectors of the two non-zero values selected for mapping to 2 of the 8 elements in each column or row can be {[1; 1] and [1; -1]} or {[1; j] and [1; -j]}.

[0268] In some embodiments, an example of a precoding matrix in the third set of precoding matrices corresponding to 4 layers may be as follows: or or For example, rows or columns can be swapped. For example, each of [a1, a2], [b1, b2] can be one of the vectors of length 2 in the first set of vectors of length 2 or the second set of vectors of length 2. For example, each of [c1, c2] and [d1, d2] can be one of the vectors of length 2 in the first set of vectors of length 2 or the second set of vectors of length 2. For example, [a1, a2], [b1, b2] can be [1; 1], [1; -1] respectively. For another example, [a1, a2], [b1, b2] can be [1; j], [1; -j] respectively. For example, [c1, c2] and [d1, d2] can be [1; 1], [1; -1] respectively. For another example, [c1, c2] and [d1, d2] can be [1; j], [1; -j] respectively. For example, [a1, a2], [b1, b2], [c1, c2], [d1, d2] can be any one of [1; 1], [1; -1], [1; j], [1; -j].

[0269] In some embodiments, if the terminal device 110 is indicated to have 4 layers, there may be a fourth set of precoding matrices corresponding to 4 layers (e.g., a fourth set of non-coherent precoding matrices). For example, each of the 8 antenna ports may be non-coherent with each other. In some embodiments, there may be a fourth set of precoding matrices (e.g., a fourth set of non-coherent precoding matrices), e.g., denoted as "Set_n4_1", and the size of the precoding matrix may be 4 by 8 or 8 by 4. In some embodiments, the precoding matrix may have 4 columns or rows. In some embodiments, there may be 8 elements in a column or row of the precoding matrix. In some embodiments, for a column or row of the precoding matrix, 1 element out of the 8 elements in the precoding matrix may have a non-zero value. For example, the non-zero value may be 1. And the other 7 elements in the precoding matrix may have the value 0. In some embodiments, for each column or row of the 4 columns or rows in the precoding matrix, the non-zero value may be mapped to 1 element out of the 8 elements, and 0 may be mapped to the other 7 elements. For example, in each row or column of the precoding matrix, the index of the element with the non-zero value may be different. For example, the indices of the 1 element with the non-zero value may be idx_1, idx_2, idx_3, idx_4 for the first, second, third, and fourth columns or rows of the precoding matrix respectively, and for each of idx_1, idx_2, idx_3, idx_4, the value may be 1 value out of {0, 1, 2, 3, 4, 5, 6, 7} or {1, 2, 3, 4, 5, 6, 7, 8}. For example, the values of idx_1, idx_2, idx_3, idx_4 may be {0, 1, 2, 3} or {0, 2, 4, 6} or {4, 5, 6, 7} or {1, 3, 5, 7} respectively. Again, for example, the values of idx_1, idx_2, idx_3, idx_4 may be {1, 2, 3, 4} or {5, 6, 7, 8} or {1, 3, 5, 7} or {2, 4, 6, 8} respectively. For example, the values of idx_1, idx_2, idx_3, idx_4 may be different from each other. In some embodiments, the values of idx_1, idx_2, idx_3, idx_4 may be based on the indices of 4 antenna ports in the first set or the second set.

[0270] In some embodiments, if the terminal device 110 is indicated to have 4 layers, there may be a fourth set of precoding matrices corresponding to 4 layers. For example, there may be one or two or four precoding matrices (e.g., non-coherent precoding matrices) in the fourth set corresponding to 4 layers.

[0271] In some embodiments, if there are 4 layers at the terminal device 110, a hybrid partial coherence matrix can be supported. For example, the antenna structure can be 4+2+2, which means that 4 antenna ports can be coherent, 2 antenna ports can be coherent, and the other 2 antenna ports can be coherent. In this case, the r1 (e.g., 1, 2, or 3) columns can be mapped with vectors of length 4, and the 4-r1 columns can be mapped with vectors of length 2, and port swapping occurs.

[0272] In other embodiments, the antenna structure can be 4+1+1+1+1, which means that 4 antenna ports can be coherent. In this case, the r1 (e.g., 1, 2, or 3) columns can have vectors of length 4, the 4-r1 columns can have 1 on one element, and row swapping occurs.

[0273] In some embodiments, the antenna structure can be 4+2+1+1, which means that 4 antenna ports can be coherent and 2 antenna ports can be coherent. For example, the r1 (e.g., 1 or 2) columns can have vectors of length 4, the r2 (e.g., 1 or 2) columns can have vectors of length 2, and the 4-r1-r2 columns can have 1 on one element.

[0274] In other embodiments, the antenna structure can be 2+2+1+1+1+1, which means that 2 antenna ports can be coherent and 2 antenna ports can be coherent. For example, the r1 (e.g., 1, 2, or 3) columns can have vectors of length 2, and the 4-r1 columns can have 1 on one element. In other embodiments, the antenna structure can be 2+1+1+1+1+1+1. Alternatively, the antenna structure can be 2+2+2+1+1.

[0275] In some embodiments, when the terminal device 110 is indicated to have 3 layers, there can be a first set of precoding matrices (e.g., the first set of fully coherent precoding matrices) corresponding to 3 layers. In some embodiments, the fully coherent precoding matrix can be expressed as:

[0276] In some embodiments, can be

[0277] In some embodiments, P can be 8 or 12 or 16. In some embodiments, l can be a non - negative integer. For example, 0 ≤ l ≤ O1N1. For another example, 0 ≤ l ≤ O1N1 / 2. For another example, l can be at least one of {0, 2, 4, 6, 8}. For another example, l can be at least one of {0, 1, 2, 3}. For another example, l can be 0 or 1. In some embodiments, m can be a non - negative integer. For example, 0 ≤ m ≤ O2N2. For another example, m can be at least one of {0, 2, 4, 6, 8}. For another example, m can be at least one of {0, 1, 2, 3}. For another example, m can be 0 or 1. For another example, m can be 0. In some embodiments, n can be a non - negative integer. For example, n can be at least one of {0, 1, 2, 3}. For another example, n can be 0 or 1. For another example, n can be 0 or 2. For another example, n can be 0. In some embodiments, l′ = l + k1. In some embodiments, m′ = m + k2. In some embodiments, k1 can be a non - negative integer. For example, k1 can be at least one of {0, O1, 2O1, 3O1}. For another example, k1 can be 0. In some embodiments, k2 can be a non - negative integer. For example, k2 can be at least one of {0, O2}. In some embodiments, k2 can be 0.

[0278] In some embodiments, there can be a parameter i 1,3 , and the values of k1 and / or k2 can be based on the value of i 1,3 , and i 1,3 can be a non - negative integer. For example, i 1,3 can be at least one of {0, 1, 2, 3}. For another example, i 1,3 can be 0 or 1. For another example, i 1,3 can be 0. In some embodiments, when N1 = 4 and N2 = 1, and when i 1,3 = 0, k1 = 0 and / or k2 = 0. In some embodiments, when N1 = 4 and N2 = 1, and when i 1,3 = 1, k1 = O1 and / or k2 = 0. In some embodiments, when N1 = 4 and N2 = 1, and when i 1,3 = 2, k1 = 2O1 and / or k2 = 0. In some embodiments, when N1 = 4 and N2 = 1, and when i 1,3 = 3, k1 = 3O1 and / or k2 = 0. In some embodiments, when N1 = 2 and N2 = 2, and when i 1,3 = 0, k1 = 0 and / or k2 = 0. In some embodiments, when N1 = 2 and N2 = 2, and when i 1,3 = 1, k1 = O1 and / or k2 = 0.

[0279] In some embodiments, there may be more than one subset of precoding matrices corresponding to 3 layers. In some embodiments, the first set of precoding matrices corresponding to 3 layers may include more than one subset. For example, there may be two or three or four subsets of precoding matrices.

[0280] In some embodiments, there may be a first subset of precoding matrices corresponding to 3 layers, and corresponding to the first subset of precoding matrices, the value of "N1" may be 4, the value of "N2" may be 1, and the value of "O1" may be 4 or 2 or 1. For example, the value of "O2" may be 1. In some embodiments, corresponding to the first subset, In some embodiments, corresponding to the first subset, m and m' may be 0. In some embodiments, corresponding to the first subset, l' = l + k1. In some embodiments, corresponding to the first subset, l may be a non - negative integer, 0 ≤ l ≤ O1N1. For example, l may be at least one of {0, 2, 4, 6}. Again, for example, l may be at least one of {0, 1, 2, 3}. Again, for example, l may be 0 or 1. Again, for example, l may be 0 or 2. In some embodiments, the number of precoding matrices in the first subset corresponding to 3 layers may be 128 or 64 or 32 or 16 or 8 or 4 or 2.

[0281] In some embodiments, there may be a second subset of precoding matrices corresponding to 3 layers, and corresponding to the second subset of precoding matrices, the value of "N1" may be 2, the value of "N2" may be 2, and the value of "O1" may be 4 or 2 or 1. For example, the value of "O2" may be 4 or 2 or 1. In some embodiments, corresponding to the second subset, In some embodiments, corresponding to the second subset, l' = l + k1. In some embodiments, corresponding to the second subset, m' = m + k2. In some embodiments, corresponding to the second subset, l may be a non - negative integer, 0 ≤ l ≤ O1N1. For example, l may be at least one of {0, 2, 4, 6}. Again, for example, l may be at least one of {0, 1, 2, 3}. Again, for example, l may be 0 or 1. Again, for example, l may be 0 or 2. In some embodiments, corresponding to the second subset, m may be a non - negative integer. For example, 0 ≤ m ≤ O2N2. Again, for example, m may be at least one of {0, 2, 4, 6}. Again, for example, m may be at least one of {0, 1, 2, 3}. Again, for example, m may be 0 or 1. Again, for example, m may be 0. In some embodiments, the number of precoding matrices in the second subset corresponding to 3 layers may be 256 or 128 or 32 or 16 or 8 or 4 or 2.

[0282] In some embodiments, if the terminal device 110 is indicated to have three layers, a third subset of precoding matrices may exist. In some embodiments, in some embodiments, a third vector may exist In some embodiments, In some embodiments, a fourth vector may exist In some embodiments, In some embodiments, N1 = 2 and N2 = 1, In some embodiments, l may be a non - negative integer. For example, 0 ≤ l ≤ O1N1. Also for example, l may be at least one of {0, 2}. Also for example, l may be at least one of {0, 1, 2, 3}. Also for example, l may be 0 or 1. In some embodiments, the value of p1 may be at least one of {0, 1, 2, 3} or {0, 1} or {0, 2}. In some embodiments, the value of p1 may be 0. In some embodiments, the value of n may be at least one of {0, 1, 2, 3} or {0, 1} or {0, 2}. In some embodiments, the value of n may be 0.

[0283] In some embodiments, a parameter i may exist 1,3 , and the values of k1 and / or k2 may be based on the value of i 1,3 value, and i 1,3 may be a non - negative integer. For example, i 1,3 may be at least one of {0, 1}. Also for example, i 1,3 may be 0. In some embodiments, in the case where N1 = 2 and N2 = 1, and in the case where i 1,3 = 0, k1 = O1 and / or k2 = 0.

[0284] In some embodiments, a third subset of precoding matrices corresponding to three layers may exist, and corresponding to the third subset of precoding matrices, the value of "N1" may be 2, the value of "N2" may be 1, and the value of "O1" may be 4 or 2 or 1. For example, the value of "O2" may be 1. In some embodiments, corresponding to the third subset, In some embodiments, corresponding to the third subset, m and m′ may be 0. In some embodiments, corresponding to the third subset, l′ = l + k1. In some embodiments, corresponding to the third subset, l may be a non - negative integer, 0 ≤ l ≤ O1N1. For example, l may be at least one of {0, 1, 2, 3}. Also for example, l may be 0 or 1. Also for example, l may be 0 or 2. In some embodiments, the number of precoding matrices in the third subset corresponding to three layers may be 64 or 32 or 16 or 8 or 4 or 2.

[0285] In some embodiments, the terminal device 110 may be indicated to have 3 layers, and the precoding matrix in the third subset corresponding to the precoding matrix of 3 layers may be expressed as: In some embodiments, may be In some embodiments, corresponding to the third subset, l′ = l + k1. In some embodiments, k1 may be O1 or 0. In some embodiments, corresponding to the third subset, m′ = m + k2. In some embodiments, k2 may be 0. In some embodiments, p may be p1.

[0286] In some embodiments, if the terminal device 110 is indicated to have 3 layers, there may be a fourth subset of precoding matrices. In some embodiments, in some embodiments, there may be a fifth vector In some embodiments, In some embodiments, there may be a sixth vector In some embodiments, In some embodiments, N1 = 2 and N2 = 1, In some embodiments, l may be a non - negative integer. For example, 0 ≤ l ≤ O1N1. Also for example, l may be at least one of {0, 2}. Also for example, l may be at least one of {0, 1, 2, 3}. Also for example, l may be 0 or 1. In some embodiments, the value of p1 may be at least one of {0, 1, 2, 3} or {0, 1} or {0, 2}. In some embodiments, the value of p1 may be 0. In some embodiments, the value of n0 may be at least one of {0, 1, 2, 3} or {0, 1} or {0, 2}. In some embodiments, the value of n0 may be 0. In some embodiments, the value of n1 may be at least one of {0, 1, 2, 3} or {0, 1} or {0, 2}. In some embodiments, the value of n1 may be 0. In some embodiments, the value of n2 may be at least one of {0, 1, 2, 3} or {0, 1} or {0, 2}. In some embodiments, the value of n2 may be 0. In some embodiments, l′ = l + k1. In some embodiments, k1 may be O1 or 0. In some embodiments, m′ = m + k2. In some embodiments, k2 may be 0. In some embodiments, m and m′ may be 0.

[0287] In some embodiments, there may be a fourth subset of precoding matrices corresponding to 3 layers, and corresponding to the fourth subset of precoding matrices, the value of "N1" may be 2, the value of "N2" may be 1, and the value of "O1" may be 4 or 2 or 1. For example, the value of "O2" may be 1. In some embodiments, corresponding to the fourth subset, In some embodiments, corresponding to the fourth subset, m and m′ can be 0. In some embodiments, corresponding to the fourth subset, l′ = l + k1. In some embodiments, corresponding to the fourth subset, l can be a non - negative integer, 0 ≤ l ≤ O1N1. For example, l can be at least one of {0, 1, 2, 3}. Again, for example, l can be 0 or 1. Again, for example, l can be 0 or 2. In some embodiments, the number of precoding matrices in the fourth subset corresponding to 3 layers can be 64 or 32 or 16 or 8 or 4 or 2.

[0288] In some embodiments, the terminal device 110 can be instructed to have 3 layers, and the precoding matrix in the fourth subset of precoding matrices corresponding to 3 layers can be expressed as: In some embodiments, can be In some embodiments, corresponding to the fourth subset, l′ = l + k1. In some embodiments, k1 can be O1 or 0. In some embodiments, corresponding to the fourth subset, m′ = m + k2. In some embodiments, k2 can be 0. In some embodiments, corresponding to the fourth subset, l′ = l + k1. In some embodiments, k1 can be O1 or 0. In some embodiments, corresponding to the fourth subset, m′ = m + k2. In some embodiments, k2 can be 0. In some embodiments, m and m′ can be 0. In some embodiments, p can be [p1 p2]. In some embodiments, n can be [n0 n1 n2].

[0289] In some embodiments, if the terminal device 110 is indicated to have 3 layers, there may be a second set of precoding matrices corresponding to 3 layers (e.g., the second set of partially coherent precoding matrices). For example, if the terminal device 110 has 8 antenna ports, or if the PUSCH transmission of the terminal device 110 is associated with 8 antenna ports, or if the PUSCH transmission of the terminal device 110 is associated with an SRS having 8 ports, then 4 antenna ports (e.g., the first set of 4 ports) may be coherent, and the other 4 antenna ports (e.g., the second set of 4 ports) may be coherent. For example, the first set of 4 ports may be non - coherent with the second set of 4 ports. In some embodiments, there may be a second set of precoding matrices corresponding to 3 layers (e.g., the second set of partially coherent precoding matrices), e.g., denoted as "Set_p3_1", and the size of the partially coherent precoding matrix may be 3 by 8 or 8 by 3. In some embodiments, the precoding matrix may have 3 columns or rows. In some embodiments, there may be 8 elements in a column or row of the precoding matrix. In some embodiments, for a column or row of the partially coherent precoding matrix, 4 out of the 8 elements in the partially coherent matrix may have non - zero values. And the other 4 elements in the partially coherent precoding matrix may have a value of 0. In some embodiments, there may be C3 columns or rows out of 3 columns or rows in the precoding matrix (e.g., the first set of C3 columns or rows. For example, C3 may be 1 or 2 or 3), and in each column, the non - zero values may be mapped to 4 out of 8 elements, and 0 may be mapped to the other 4 elements. For example, in the first set of C3 columns or rows, the indices of the 4 elements with non - zero values may be the same. For example, the indices of the 4 elements with non - zero values may be idx_1, and idx_1 may be 4 values from {0,1,2,3,4,5,6,7} or {1,2,3,4,5,6,7,8}. In some embodiments, the 4 values of idx_1 may be based on the indices of 4 antenna ports in the first set or the second set. For example, idx_1 may be {0,1,2,3} or {0,2,4,6} or {1,2,3,4} or {1,3,5,7}. In some embodiments, for the other 3 - C3 columns, 3 - C3 vectors of length 4 from the first set or the second set may be selected. In some embodiments, for the other 3 - C3 columns or rows out of 3 columns or rows in the precoding matrix (e.g., the second set of 3 - C3 columns or rows), in each column or row, the non - zero values may be mapped to 4 out of 8 elements, and 0 may be mapped to the other 4 elements. For example, in the second set of 3 - C3 columns or rows, the indices of the 4 elements with non - zero values may be the same. For example, the indices of the 4 elements with non - zero values may be idx_2, and idx_2 may be 4 values from {0,1,2,3,4,5,6,7} or {1,2,3,4,5,6,7,8}.In some embodiments, the 4 values of idx_2 can be based on the indices of 4 antenna ports in the first group or the second group. For example, idx_2 can be {4, 5, 6, 7} or {1, 3, 5, 7} or {5, 6, 7, 8} or {2, 4, 6, 8}. In some embodiments, any value of idx_1 can be different from any value of idx_2. In some embodiments, C3 can be 3, and there may be no second group of columns or rows.

[0290] In some embodiments, there can be two groups of vectors of length 4, and each group can include 4 vectors of length 4. In some embodiments, the values in the vectors of length 4 can be applied to map to 4 non-zero values of 4 elements in the columns or rows of the precoding matrix. For example, the first group of vectors of length 4 can be {[1; 1; 1; 1], [1; -1; 1; -1], [1; 1; -1; -1], [1; -1; -1; 1]}. As another example, the second group of vectors of length 4 can be {[1; 1; j; j], [1; -1; j; -j], [1; 1; -j; -j], [1; -1; -j; j]}. In some embodiments, the 4 values in each vector in the first group or the second group can be mapped to 4 of the 8 elements, and 0 can be mapped to the other 4 elements in the columns or rows of the precoding matrix.

[0291] In some embodiments, an example of the precoding matrix in the second group of precoding matrices corresponding to 3 layers can be as follows: or or For example, rows or columns can be swapped. For example, rows or columns can be swapped. For example, each of [a1, a2, a3, a4], [b1, b2, b3, b4], [c1, c2, c3, c4] can be one of the vectors of length 4 in the first set of vectors of length 4 or the second set of vectors of length 4. For example, [a1, a2, a3, a4], [b1, b2, b3, b4], [c1, c2, c3, c4] can be three of [1; 1; 1; 1], [1; -1; 1; -1], [1; 1; -1; -1], and [1; -1; -1; 1]. For another example, [a1, a2, a3, a4], [b1, b2, b3, b4], [c1, c2, c3, c4] can be three of [1; 1; j; j], [1; -1; j; -j], [1; 1; -j; -j], and [1; -1; -j; j]. For example, each of [a1, a2, a3, a4], [b1, b2, b3, b4], [c1, c2, c3, c4] can be one of the vectors of length 4 in the first set of vectors of length 4 or the second set of vectors of length 4. For example, [a1, a2, a3, a4], [b1, b2, b3, b4] can be two of the vectors among [1; 1; 1; 1], [1; -1; 1; -1], [1; 1; -1; -1], and [1; -1; -1; 1]. For another example, [a1, a2, a3, a4], [b1, b2, b3, b4] can be two of [1; 1; j; j], [1; -1; j; -j], [1; 1; -j; -j], and [1; -1; -j; j]. For example, [c1, c2, c3, c4] can be one of the vectors among [1; 1; j; j], [1; -1; j; -j], [1; 1; -j; -j], and [1; -1; -j; j]. For another example, [c1, c2, c3, c4] can be one of the vectors among [1; 1; j; j], [1; -1; j; -j], [1; 1; -j; -j], and [1; -1; -j; j].

[0292] In some embodiments, s3 can be a positive integer. For example, 1 ≤ s3 ≤ 64. For example, s3 can be 64 or 32 or 16 or 8 or 4 or 5 or 2 or 24 or 12 or 6 or 3.

[0293] In some embodiments, if the terminal device 110 is indicated to have three layers, there may be a third set of precoding matrices (e.g., a third set of partial interference precoding matrices) corresponding to three layers. For example, the structure of eight ports can be 2+2+2+2, which means there are four groups, each group including two antenna ports, and within each group, the two antenna ports can be coherent. For example, between groups, the antenna ports may not be coherent. In some embodiments, there may be a third set of precoding matrices (e.g., a third set of partial interference precoding matrices), such as denoted as "Set_p3_2", and the size of the precoding matrix can be 3 by 8 or 8 by 3. In some embodiments, the precoding matrix may have three columns or rows. In some embodiments, there may be eight elements in a column or row of the precoding matrix. In some embodiments, for a column or row of the precoding matrix, two of the eight elements in the precoding matrix may have non-zero values. And the other six elements in the precoding matrix may have a value of 0. In some embodiments, there may be one or two columns or rows (e.g., the first set of one or two columns or rows) out of the three columns or rows in the precoding matrix, and in each column or row, the non-zero values may be mapped to two of the eight elements, and 0 may be mapped to the other six elements. For example, in the first set of one or two columns or rows, the indices of the two elements with non-zero values may be the same. For example, the indices of the two elements with non-zero values may be idx_1, and idx_1 may be two values from {0,1,2,3,4,5,6,7} or {1,2,3,4,5,6,7,8}. In some embodiments, the two values of idx_1 may be based on the indices of two antenna ports out of the four antenna ports in the first group. In some embodiments, the two values of idx_1 may be based on the indices of two antenna ports in the third group or the fourth group or the fifth group or the sixth group. For example, idx_1 may be {0,1} or {0,2} or {1,2} or {1,3} or {0,4} or {1,5}. In some embodiments, there may be one or two columns or rows (e.g., the second set of one or two columns or rows) out of the three columns or rows in the precoding matrix, and in each column or row, the non-zero values may be mapped to two of the eight elements, and 0 may be mapped to the other six elements. For example, in the second set of one or two columns or rows, the indices of the two elements with non-zero values may be the same. For example, the indices of the two elements with non-zero values may be idx_2, and idx_2 may be two values from {0,1,2,3,4,5,6,7} or {1,2,3,4,5,6,7,8}. In some embodiments, the two values of idx_2 may be based on the indices of two antenna ports out of the four antenna ports in the first group or the second group. In some embodiments, the two values of idx_2 may be based on the indices of two antenna ports in the third group or the fourth group or the fifth group or the sixth group.For example, idx_2 can be {2,3} or {1,3} or {3,4} or {2,4} or {1,5} or {2,6}. In some embodiments, there may be 1 or 2 columns or rows out of 3 columns or rows in the precoding matrix (e.g., the third group of 1 or 2 columns or rows), and in each column or row, the non-zero values can be mapped to 2 out of 8 elements, and 0 can be mapped to the other 6 elements. For example, in the third group of 1 or 2 columns or rows, the indices of the 2 elements with non-zero values can be the same. For example, the indices of the 2 elements with non-zero values can be idx_3, and idx_3 can be 2 values out of {0,1,2,3,4,5,6,7} or {1,2,3,4,5,6,7,8}. For example, idx_3 can be {4,5} or {4,6} or {5,6} or {5,7} or {2,6} or {3,7}. In some embodiments, the 2 values of idx_3 can be based on the indices of two antenna ports out of the 4 antenna ports in the first group or the second group. In some embodiments, the 2 values of idx_3 can be based on the indices of 2 antenna ports in the third group or the fourth group or the fifth group or the sixth group. In some embodiments, there may be 1 or 2 columns or rows out of 3 columns or rows in the precoding matrix (e.g., the fourth group of 1 or 2 columns or rows), and in each column or row, the non-zero values can be mapped to 2 out of 8 elements, and 0 can be mapped to the other 6 elements. For example, in the fourth group of 1 or 2 columns or rows, the indices of the 2 elements with non-zero values can be the same. For example, the indices of the 2 elements with non-zero values can be idx_4, and idx_4 can be 2 values out of {0,1,2,3,4,5,6,7} or {1,2,3,4,5,6,7,8}. In some embodiments, the 2 values of idx_4 can be based on the indices of the remaining two out of the 4 antenna ports in the first group or the second group. In some embodiments, the 2 values of idx_4 can be based on the indices of 2 antenna ports in the third group or the fourth group or the fifth group or the sixth group. For example, idx_4 can be {6,7} or {5,7} or {7,8} or {6,8} or {3,7} or {4,8}. In some embodiments, any value of idx_1, any value of idx_2, any value of idx_3, and any value of idx_4 can be different from each other. In some embodiments, there may be three groups out of the first group, the second group, the third group, and the fourth group. In some embodiments, the total number of columns or rows in the first group and / or the second group and / or the third group and / or the fourth group can be 3. In some embodiments, there may be two groups out of the four groups, and one group has 2 columns or rows, and the other group has 1 column or row. In some embodiments, there may be three groups out of the four groups, and each group has 1 column or row.

[0294] In some embodiments, there can be a set of 4 vectors of length 2, and each of the vectors of length 2 can be applied as two non-zero values in a column or a row of a precoding matrix. In some embodiments, for the third set of precoding matrices corresponding to 3 layers, e.g., Set_p3_2, two vectors of length 2 can be selected from the 4 vectors of length 2, and the 2 values in each vector can be mapped to 2 of the 8 elements, and 0 can be mapped to the other elements in a column or a row of the precoding matrix. In some embodiments, there can be two sets of vectors of length 2, and each set can include 2 vectors of length 2. In some embodiments, the two values in a vector of length 2 can be applied as two non-zero values mapped to 2 elements in a column or a row of the precoding matrix. For example, the first set of vectors of length 2 can be {[1; 1], [1; -1]}. As another example, the second set of vectors of length 2 can be {[1; j], [1; -j]}. In some embodiments, the 2 values in each vector in the first set or the second set can be mapped to 2 of the 8 elements, and 0 can be mapped to the other 6 elements in a column or a row of the precoding matrix. In some embodiments, for the first set of 2 columns or rows and / or for the second set of 1 or 2 columns or rows and / or for the third set of 1 or 2 columns or rows and / or for the fourth set of 1 or 2 columns or rows, the two vectors of the 2 non-zero values selected for mapping to 2 of the 8 elements in each column or row can be {[1; 1] and [1; -1]} or {[1; j] and [1; -j]}.

[0295] In some embodiments, an example of a precoding matrix in the third set of precoding matrices corresponding to 3 layers can be as follows: or or For example, rows or columns can be swapped. For example, each of [a1, a2], [b1, b2], [c1, c2] can be one of the vectors of length 2 in the first set of vectors of length 2 or the second set of vectors of length 2. For example, [a1, a2], [b1, b2] can be [1; 1], [1; -1] respectively. As another example, [a1, a2], [b1, b2] can be [1; j], [1; -j] respectively. For example, [a1, a2], [b1, b2], [c1, c2] can be any one of [1; 1], [1; -1], [1; j], [1; -j].

[0296] In some embodiments, if the terminal device 110 is indicated to have 3 layers, there may be a fourth set of precoding matrices corresponding to 3 layers (e.g., a fourth set of non-coherent precoding matrices). For example, each of the 8 antenna ports may be non-coherent with each other. In some embodiments, there may be a fourth set of precoding matrices (e.g., a fourth set of non-coherent precoding matrices), such as denoted as "Set_n3_1", and the size of the precoding matrix may be 3 by 8 or 8 by 3. In some embodiments, the precoding matrix may have 3 columns or rows. In some embodiments, there may be 8 elements in a column or row of the precoding matrix. In some embodiments, for a column or row of the precoding matrix, 1 element out of the 8 elements in the precoding matrix may have a non-zero value. For example, the non-zero value may be 1. And the other 7 elements in the precoding matrix may have a value of 0. In some embodiments, for each column or row of the 3 columns or rows in the precoding matrix, the non-zero value may be mapped to 1 element out of the 8 elements, and 0 may be mapped to the other 7 elements. For example, in each row or column of the precoding matrix, the index of the element with the non-zero value may be different. For example, the indexes of the 1 element with the non-zero value may be idx_1, idx_2, idx_3 for the first, second, and third columns or rows of the precoding matrix respectively, and for each of idx_1, idx_2, idx_3, the value may be one value in {0, 1, 2, 3, 4, 5, 6, 7} or {1, 2, 3, 4, 5, 6, 7, 8}. In some embodiments, the values of idx_1, idx_2, and idx_3 may be based on the indexes of three antenna ports out of the 4 antenna ports in the first set or the second set. In some embodiments, the values of idx_1, idx_2, and idx_3 may be based on the indexes of 2 antenna ports in the third set or the fourth set or the fifth set or the sixth set, and based on the index of one antenna port out of the 2 antenna ports in the third set or the fourth set or the fifth set. For example, the values of idx_1, idx_2, idx_3 may be one value in {0, 1, 2, 3} or {0, 2, 4, 6} or {4, 5, 6, 7} or {1, 3, 5, 7} respectively. Again, for example, the values of idx_1, idx_2, idx_3 may be one value in {1, 2, 3, 4} or {5, 6, 7, 8} or {1, 3, 5, 7} or {2, 4, 6, 8} respectively. For example, the values of idx_1, idx_2, idx_3 may be different from each other.

[0297] In some embodiments, if the terminal device 110 is indicated to have 3 layers, there may be a fourth set of precoding matrices corresponding to 3 layers. For example, there may be one or two or four precoding matrices (e.g., non-coherent precoding matrices) in the fourth set corresponding to 3 layers. For example, the precoding matrices in the fourth set of precoding matrices corresponding to 3 layers may be or

[0298] In some embodiments, the terminal device 110 is indicated to have 2 layers, and there may be a first set of precoding matrices corresponding to 2 layers (e.g., the first set of full-phase precoding matrices). In some embodiments, the full-phase precoding matrix can be expressed as:

[0299] In some embodiments, may be

[0300] In some embodiments, P may be 8 or 12 or 16. In some embodiments, l may be a non-negative integer. For example, 0≤l≤O1N1. For another example, 0≤l≤O1N1 / 2. For another example, l may be at least one of {0, 2, 4, 6}. For another example, l may be at least one of {0, 1, 2, 3}. For another example, l may be 0 or 1. In some embodiments, m may be a non-negative integer. For example, 0≤m≤O2N2. For another example, m may be at least one of {0, 2, 4, 6}. For another example, m may be at least one of {0, 1, 2, 3}. For another example, m may be 0 or 1. For another example, m may be 0. In some embodiments, n may be a non-negative integer. For example, n may be at least one of {0, 1, 2, 3}. For another example, n may be 0 or 1. For another example, n may be 0 or 2. For another example, n may be 0. In some embodiments, l′ = l + k1. In some embodiments, m′ = m + k2. In some embodiments, k1 may be a non-negative integer. For example, k1 may be at least one of {0, O1, 2O1, 3O1}. For another example, k1 may be 0. In some embodiments, k2 may be a non-negative integer. For example, k2 may be at least one of {0, O2}. In some embodiments, k2 may be 0.

[0301] In some embodiments, there may be a parameter i 1,3 , and the values of k1 and / or k2 may be based on the value of i 1,3 , and i 1,3 may be a non-negative integer. For example, i 1,3 may be at least one of {0, 1, 2, 3}. For another example, i 1,3 may be 0 or 1. For another example, i 1,3 may be 0. In some embodiments, in the case where N1 = 4 and N2 = 1, and in the case where i 1,3 = 0, k1 = 0 and / or k2 = 0. In some embodiments, in the case where N1 = 4 and N2 = 1, and in the case where i 1,3when = 1, k1 = O1 and / or k2 = 0. In some embodiments, when N1 = 4 and N2 = 1, and when i 1,3 = 2, k1 = 2O1 and / or k2 = 0. In some embodiments, when N1 = 4 and N2 = 1, and when i 1,3 = 3, k1 = 3O1 and / or k2 = 0. In some embodiments, when N1 = 2 and N2 = 2, and when i 1,3 = 0, k1 = 0 and / or k2 = 0. In some embodiments, when N1 = 2 and N2 = 2, and when i 1,3 = 1, k1 = O1 and / or k2 = 0.

[0302] In some embodiments, there may be more than one subset of precoding matrices corresponding to two layers. In some embodiments, the first set of precoding matrices corresponding to two layers may include more than one subset. For example, there may be two or three or four subsets of precoding matrices.

[0303] In some embodiments, there may be a first subset of precoding matrices corresponding to two layers, and corresponding to the first subset of precoding matrices, the value of "N1" may be 4, the value of "N2" may be 1, and the value of "O1" may be 4 or 2 or 1. For example, the value of "O2" may be 1. In some embodiments, corresponding to the first subset, In some embodiments, corresponding to the first subset, m and m' may be 0. In some embodiments, corresponding to the first subset, l' = l + k1. In some embodiments, corresponding to the first subset, l may be a non-negative integer, 0 ≤ l ≤ O1N1. For example, l may be at least one of {0, 2, 4, 6}. Again, for example, l may be at least one of {0, 1, 2, 3}. Again, for example, l may be 0 or 1. Again, for example, l may be 0 or 2. In some embodiments, the number of precoding matrices in the first subset corresponding to two layers may be 128 or 64 or 32 or 16 or 8 or 4 or 2.

[0304] In some embodiments, there may be a second subset of precoding matrices corresponding to two layers, and corresponding to the second subset of precoding matrices, the value of "N1" may be 2, the value of "N2" may be 2, and the value of "O1" may be 4 or 2 or 1. For example, the value of "O2" may be 4 or 2 or 1. In some embodiments, corresponding to the second subset, In some embodiments, corresponding to the second subset, l′ = l + k1. In some embodiments, corresponding to the second subset, m′ = m + k2. In some embodiments, corresponding to the second subset, l can be a non - negative integer, 0 ≤ l ≤ O1N1. For example, l can be at least one of {0, 2, 4, 6}. For another example, l can be at least one of {0, 1, 2, 3}. For another example, l can be 0 or 1. For another example, l can be 0 or 2. In some embodiments, corresponding to the second subset, m can be a non - negative integer. For example, 0 ≤ m ≤ O2N2. For another example, m can be at least one of {0, 2, 4, 6}. For another example, m can be at least one of {0, 1, 2, 3}. For another example, m can be 0 or 1. For another example, m can be 0. In some embodiments, the number of precoding matrices in the second subset corresponding to 2 layers can be 256 or 128 or 32 or 16 or 8 or 4 or 2.

[0305] In some embodiments, if the terminal device 110 is indicated to have 2 layers, there can be a third subset of precoding matrices. In some embodiments, in some embodiments, there can be a third vector In some embodiments, In some embodiments, there can be a fourth vector In some embodiments, In some embodiments, N1 = 2 and N2 = 1, In some embodiments, l can be a non - negative integer. For example, 0 ≤ l ≤ O1N1. For another example, l can be at least one of {0, 2}. For another example, l can be at least one of {0, 1, 2, 3}. For another example, l can be 0 or 1. In some embodiments, the value of p1 can be at least one of {0, 1, 2, 3} or {0, 1} or {0, 2}. In some embodiments, the value of p1 can be 0. In some embodiments, the value of n can be at least one of {0, 1, 2, 3} or {0, 1} or {0, 2}. In some embodiments, the value of n can be 0.

[0306] In some embodiments, there can be a parameter i 1,3 , and the values of k1 and / or k2 can be based on the value of i 1,3 value, and i 1,3 can be a non - negative integer. For example, i 1,3 can be at least one of {0, 1}. For another example, i 1,3 can be 0. In some embodiments, in the case where N1 = 2 and N2 = 1, and in the case where i 1,3 = 0, k1 = O1 and / or k2 = 0.

[0307] In some embodiments, there may be a third subset of precoding matrices corresponding to two layers, and corresponding to the third subset of precoding matrices, the value of "N1" may be 2, the value of "N2" may be 1, and the value of "O1" may be 4 or 2 or 1. For example, the value of "O2" may be 1. In some embodiments, corresponding to the third subset, In some embodiments, corresponding to the third subset, m and m' may be 0. In some embodiments, corresponding to the third subset, l' = l + k1. In some embodiments, corresponding to the third subset, l may be a non-negative integer, 0 ≤ l ≤ O1N1. For example, l may be at least one of {0, 1, 2, 3}. Again, for example, l may be 0 or 1. Again, for example, l may be 0 or 2. In some embodiments, the number of precoding matrices in the third subset corresponding to two layers may be 64 or 32 or 16 or 8 or 4 or 2.

[0308] In some embodiments, the terminal device 110 may be instructed to have two layers, and the precoding matrices in the third subset of precoding matrices corresponding to two layers may be represented as: In some embodiments, may be In some embodiments, corresponding to the third subset, l' = l + k1. In some embodiments, k1 may be O1 or 0. In some embodiments, corresponding to the third subset, m' = m + k2. In some embodiments, k2 may be 0. In some embodiments, p may be p1.

[0309] In some embodiments, if the terminal device 110 is instructed to have two layers, there may be a fourth subset of precoding matrices. In some embodiments, in some embodiments, there may be a fifth vector In some embodiments, In some embodiments, there may be a sixth vector In some embodiments, In some embodiments, N1 = 2 and N2 = 1, In some embodiments, l can be a non - negative integer. For example, 0 ≤ l ≤ O1N1. For another example, l can be at least one of {0, 2}. For another example, l can be at least one of {0, 1, 2, 3}. For another example, l can be 0 or 1. In some embodiments, the value of p1 can be at least one of {0, 1, 2, 3} or {0, 1} or {0, 2}. In some embodiments, the value of p1 can be 0. In some embodiments, the value of n0 can be at least one of {0, 1, 2, 3} or {0, 1} or {0, 2}. In some embodiments, the value of n0 can be 0. In some embodiments, the value of n1 can be at least one of {0, 1, 2, 3} or {0, 1} or {0, 2}. In some embodiments, the value of n1 can be 0. In some embodiments, the value of n2 can be at least one of {0, 1, 2, 3} or {0, 1} or {0, 2}. In some embodiments, the value of n2 can be 0. In some embodiments, l′ = l + k1. In some embodiments, k1 can be O1 or 0. In some embodiments, m′ = m + k2. In some embodiments, k2 can be 0. In some embodiments, m and m′ can be 0.

[0310] In some embodiments, there can be a fourth subset of precoding matrices corresponding to 2 layers, and corresponding to the fourth subset of precoding matrices, the value of "N1" can be 2, the value of "N2" can be 1, and the value of "O1" can be 4 or 2 or 1. For example, the value of "O2" can be 1. In some embodiments, corresponding to the fourth subset, In some embodiments, corresponding to the fourth subset, m and m′ can be 0. In some embodiments, corresponding to the fourth subset, l′ = l + k1. In some embodiments, corresponding to the fourth subset, l can be a non - negative integer, 0 ≤ l ≤ O1N1. For example, l can be at least one of {0, 1, 2, 3}. For another example, l can be 0 or 1. For another example, l can be 0 or 2. In some embodiments, the number of precoding matrices in the fourth subset of precoding matrices corresponding to 2 layers can be 64 or 32 or 16 or 8 or 4 or 2.

[0311] In some embodiments, the terminal device 110 can be indicated to have 2 layers, and the precoding matrices in the fourth subset of precoding matrices corresponding to 2 layers can be represented as: In some embodiments, can be In some embodiments, corresponding to the fourth subset, l′ = l + k1. In some embodiments, k1 can be O1 or 0. In some embodiments, corresponding to the fourth subset, m′ = m + k2. In some embodiments, k2 can be 0. In some embodiments, corresponding to the fourth subset, l′ = l + k1. In some embodiments, k1 can be O1 or 0. In some embodiments, corresponding to the fourth subset, m′ = m + k2. In some embodiments, k2 can be 0. In some embodiments, m and m′ can be 0. In some embodiments, p can be [p1 p2]. In some embodiments, n can be [n0 n1 n2].

[0312] In some embodiments, if the terminal device 110 is indicated to have two layers, there may be a second set of precoding matrices corresponding to two layers (e.g., a second set of partially coherent precoding matrices). For example, if the terminal device 110 has eight antenna ports, or if the PUSCH transmission of the terminal device 110 is associated with eight antenna ports, or if the PUSCH transmission of the terminal device 110 is associated with an SRS having eight ports, then four antenna ports (e.g., a first set of four ports) may be coherent, and the other four antenna ports (e.g., a second set of four ports) may be coherent. For example, the first set of four ports may be non-coherent with the second set of four ports. In some embodiments, there may be a second set of precoding matrices corresponding to two layers (e.g., a second set of partially coherent precoding matrices), such as denoted as "Set_p2_1", and the size of the partially coherent precoding matrix may be 2 by 8 or 8 by 2. In some embodiments, the precoding matrix may have two columns or rows. In some embodiments, there may be eight elements in a column or row of the precoding matrix. In some embodiments, for a column or row of the partially coherent precoding matrix, four of the eight elements in the partially coherent matrix may have non-zero values. And the other four elements in the partially coherent precoding matrix may have a value of 0. In some embodiments, there may be C4 columns or rows (e.g., a first set of C4 columns or rows. For example, C4 = 1 or 2) in the two columns or rows of the precoding matrix, and in each column, the non-zero values may be mapped to four of the eight elements, and 0 may be mapped to the other four elements. For example, in the first set of C4 columns or rows, the indices of the four elements having non-zero values may be the same. For example, the indices of the four elements having non-zero values may be idx_1, and idx_1 may be four values from {0, 1, 2, 3, 4, 5, 6, 7} or {1, 2, 3, 4, 5, 6, 7, 8}. In some embodiments, the four values of idx_1 may be based on the indices of the four antenna ports in the first set or the second set. For example, idx_1 may be {0, 1, 2, 3} or {0, 2, 4, 6} or {1, 2, 3, 4} or {1, 3, 5, 7}. In some embodiments, for the other 2 - C4 columns or rows, 2 - C4 vectors of length four from the first set or the second set of vectors of length four may be selected. In some embodiments, for the other 2 - C4 columns or rows (e.g., a second set of 2 - C4 columns or rows) in the two columns or rows of the precoding matrix, in each column or row, the non-zero values may be mapped to four of the eight elements, and 0 may be mapped to the other four elements. For example, in the second set of 2 - C4 columns or rows, the indices of the four elements having non-zero values may be the same. For example, the indices of the four elements having non-zero values may be idx_2, and idx_2 may be four values from {0, 1, 2, 3, 4, 5, 6, 7} or {1, 2, 3, 4, 5, 6, 7, 8}.In some embodiments, the four values of idx_2 can be based on the indices of four antenna ports in the first group or the second group. For example, idx_2 can be {4, 5, 6, 7} or {1, 3, 5, 7} or {5, 6, 7, 8} or {2, 4, 6, 8}. In some embodiments, any value of idx_1 can be different from any value of idx_2. In some embodiments, C4 can be 2, and there may be no second set of columns or rows.

[0313] In some embodiments, there may be two sets of vectors of length 4, and each set may include four vectors of length 4. In some embodiments, the values in the vectors of length 4 can be applied to four non-zero values that map to four elements in a column or a row of a precoding matrix. For example, the first set of vectors of length 4 can be {[1; 1; 1; 1], [1; -1; 1; -1], [1; 1; -1; -1], [1; -1; -1; 1]}. As another example, the second set of vectors of length 4 can be {[1; 1; j; j], [1; -1; j; -j], [1; 1; -j; -j], [1; -1; -j; j]}. In some embodiments, the four values in each vector in the first group or the second group can be mapped to four of the eight elements, and 0 can be mapped to the other four elements in a column or a row of the precoding matrix. In some embodiments,

[0314] In some embodiments, an example of the precoding matrix in the second set of precoding matrices corresponding to two layers can be as follows: or For example, rows or columns can be swapped. For example, rows or columns can be swapped. For example, each of [a1, a2, a3, a4], [b1, b2, b3, b4] can be one of the vectors of length 4 in the first set of vectors of length 4 or the second set of vectors of length 4. For example, [a1, a2, a3, a4], [b1, b2, b3, b4] can be two of [1; 1; 1; 1], [1; -1; 1; -1], [1; 1; -1; -1], and [1; -1; -1; 1]. As another example, [a1, a2, a3, a4], [b1, b2, b3, b4] can be two of [1; 1; j; j], [1; -1; j; -j], [1; 1; -j; -j], and [1; -1; -j; j]. For example, each of [a1, a2, a3, a4], [b1, b2, b3, b4] can be one of the vectors of length 4 in the first set of vectors of length 4 or the second set of vectors of length 4.

[0315] In some embodiments, s2 can be a positive integer. For example, 1 ≤ s2 ≤ 64. For example, s2 can be 64 or 32 or 16 or 8 or 4 or 2.

[0316] In some embodiments, if the terminal device 110 is indicated to have two layers, there may be a third set of precoding matrices (e.g., the third set of partial interference precoding matrices) corresponding to two layers. For example, the structure of eight ports can be 2+2+2+2, which means there are four groups, each group including two antenna ports, and within each group, the two antenna ports can be coherent. For example, between groups, the antenna ports may not be coherent. In some embodiments, there may be a third set of precoding matrices (e.g., the third set of partial interference precoding matrices), such as denoted as "Set_p2_2", and the size of the precoding matrix can be 2 by 8 or 8 by 2. In some embodiments, the precoding matrix may have two columns or rows. In some embodiments, there may be eight elements in a column or row of the precoding matrix. In some embodiments, for a column or row of the precoding matrix, two of the eight elements in the precoding matrix may have non-zero values. And the other six elements in the precoding matrix may have a value of 0. In some embodiments, there may be one or two columns or rows out of two columns or rows in the precoding matrix (e.g., the first set of one or two columns or rows), and in each column or row, the non-zero values may be mapped to two of the eight elements, and 0 may be mapped to the other six elements. For example, in the first set of one or two columns or rows, the indices of the two elements with non-zero values may be the same. For example, the indices of the two elements with non-zero values may be idx_1, and idx_1 may be one or two values in {0,1,2,3,4,5,6,7} or {1,2,3,4,5,6,7,8}. In some embodiments, the two values of idx_1 may be based on the indices of two of the four antenna ports in the first set or the second set. In some embodiments, the two values of idx_1 may be based on the indices of two antenna ports in the third set or the fourth set or the fifth set or the sixth set. For example, idx_1 may be {0,1} or {0,2} or {1,2} or {1,3} or {0,4} or {1,5}. In some embodiments, there may be one or two columns or rows out of two columns or rows in the precoding matrix (e.g., the second set of one or two columns or rows), and in each column or row, the non-zero values may be mapped to two of the eight elements, and 0 may be mapped to the other six elements. For example, in the second set of one or two columns or rows, the indices of the two elements with non-zero values may be the same. For example, the indices of the two elements with non-zero values may be idx_2, and idx_2 may be one or two values in {0,1,2,3,4,5,6,7} or {1,2,3,4,5,6,7,8}. In some embodiments, the two values of idx_2 may be based on the indices of the remaining two of the four antenna ports in the first set or the second set. In some embodiments, the two values of idx_2 may be based on the indices of two antenna ports in the third set or the fourth set or the fifth set or the sixth set.For example, idx_2 can be {2, 3} or {1, 3} or {3, 4} or {2, 4} or {1, 5} or {2, 6}. In some embodiments, any value of idx_1 and any value of idx_2 can be different from each other. In some embodiments, the total number of columns or rows in the first group and / or the second group can be 2. In some embodiments, there can be a first group and a second group, and each group has 1 column or row. In some embodiments, there can be only one first group, and the first group has 2 columns or rows.

[0317] In some embodiments, there can be a set of 4 vectors of length 2, and each of the vectors of length 2 can be applied as two non-zero values in a column or a row of a precoding matrix. In some embodiments, for a third set of precoding matrices corresponding to 2 layers, e.g., Set_p2_2, two vectors of length 2 can be selected from the 4 vectors of length 2, and the 2 values in each vector can be mapped to 2 of the 8 elements, and 0 can be mapped to the other elements in a column or a row of the precoding matrix. In some embodiments, there can be two sets of vectors of length 2, and each set can include 2 vectors of length 2. In some embodiments, the two values in a vector of length 2 can be applied as two non-zero values mapped to 2 elements in a column or a row of the precoding matrix. For example, the first set of vectors of length 2 can be {[1; 1], [1; -1]}. As another example, the second set of vectors of length 2 can be {[1; j], [1; -j]}. In some embodiments, the 2 values in each vector in the first set or the second set can be mapped to 2 of the 8 elements, and 0 can be mapped to the other 6 elements in a column or a row of the precoding matrix. In some embodiments, for the first set of 2 columns or rows and / or for the second set of 1 or 2 columns or rows and / or for the third set of 1 or 2 columns or rows and / or for the fourth set of 1 or 2 columns or rows, the two vectors for the two non-zero values selected to be mapped to 2 of the 8 elements in each column or row can be {[1; 1] and [1; -1]} or {[1; j] and [1; -j]}.

[0318] In some embodiments, an example of a precoding matrix in the third set of precoding matrices corresponding to 2 layers can be as follows: or For example, rows or columns can be swapped. For example, each of [a1, a2] and [b1, b2] can be one of the vectors of length 2 in the first set of vectors of length 2 or the second set of vectors of length 2. For example, [a1, a2] and [b1, b2] can be [1; 1] and [1; -1] respectively. As another example, [a1, a2] and [b1, b2] can be [1; j] and [1; -j] respectively. For example, [a1, a2] and [b1, b2] can be any of [1; 1], [1; -1], [1; j], and [1; -j].

[0319] In some embodiments, if the terminal device 110 is indicated to have two layers, there can be a fourth set of precoding matrices (e.g., a fourth set of non-coherent precoding matrices) corresponding to two layers. For example, each of the eight antenna ports can be non-coherent with each other. In some embodiments, there can be a fourth set of precoding matrices (e.g., a fourth set of non-coherent precoding matrices), for example, denoted as "Set_n2_1", and the size of the precoding matrix can be 2 by 8 or 8 by 2. In some embodiments, the precoding matrix can have two columns or rows. In some embodiments, there can be eight elements in a column or row of the precoding matrix. In some embodiments, for a column or row of the precoding matrix, one of the eight elements in the precoding matrix can have a non-zero value. For example, the non-zero value can be 1. And the other seven elements in the precoding matrix can have a value of 0. In some embodiments, for each column or row of the two columns or rows in the precoding matrix, the non-zero value can be mapped to one of the eight elements, and 0 can be mapped to the other seven elements. For example, in each row or column of the precoding matrix, the indices of the elements with non-zero values can be different. For example, the indices of the one element with a non-zero value can be idx_1 and idx_2 for the first column, second column, or row of the precoding matrix respectively, and for each of idx_1 and idx_2, the value can be one value in {0, 1, 2, 3, 4, 5, 6, 7} or {1, 2, 3, 4, 5, 6, 7, 8}. In some embodiments, the values of idx_1 and idx_2 can be based on the indices of two antenna ports among the four antenna ports in the first set or the second set. In some embodiments, the values of idx_1 and idx_2 can be based on the indices of two antenna ports in the third set or the fourth set or the fifth set or the sixth set. For example, the values of idx_1 and idx_2 can be one value in {0, 1, 2, 3} or {0, 2, 4, 6} or {4, 5, 6, 7} or {1, 3, 5, 7} respectively. As another example, the values of idx_1 and idx_2 can be {1, 2}, {3, 4} or {5, 6}, {7, 8} or {1, 3}, {5, 7} or {2, 4}, {6, 8}. For example, the values of idx_1 and idx_2 can be different from each other.

[0320] In some embodiments, if the terminal device 110 is indicated to have 2 layers, there may be a fourth set of precoding matrices corresponding to 2 layers. For example, there may be one or two or four or six or twelve precoding matrices (e.g., non-interfering precoding matrices) in the fourth set corresponding to 2 layers. For example, the precoding matrices in the fourth set of precoding matrices corresponding to 2 layers may be or or or or or

[0321] For example, s2 = 8.

[0322] In some embodiments, when the terminal device 110 is indicated to have 1 layer, there may be a first set of precoding matrices corresponding to 1 layer (e.g., the first set of full-phase precoding matrices). In some embodiments, the full-phase precoding matrix can be expressed as:

[0323] In some embodiments, can be

[0324] In some embodiments, P can be 8 or 12 or 16. In some embodiments, l can be a non-negative integer. For example, 0 ≤ l ≤ O1N1. For another example, 0 ≤ l ≤ O1N1 / 2. For another example, l can be at least one of {0, 2, 4, 6}. For another example, l can be at least one of {0, 1, 2, 3}. For another example, l can be 0 or 1. In some embodiments, m can be a non-negative integer. For example, 0 ≤ m ≤ O2N2. For another example, m can be at least one of {0, 2, 4, 6}. For another example, m can be at least one of {0, 1, 2, 3}. For another example, m can be 0 or 1. For another example, m can be 0. In some embodiments, n can be a non-negative integer. For example, n can be at least one of {0, 1, 2, 3}. For another example, n can be 0 or 1. For another example, n can be 0 or 2. For another example, n can be 0.

[0325] In some embodiments, there may be more than one subset of precoding matrices corresponding to 1 layer. In some embodiments, the first set of precoding matrices corresponding to 1 layer may include more than one subset. For example, there may be two or three or four subsets of precoding matrices.

[0326] In some embodiments, there may be a first subset of precoding matrices corresponding to layer 1, and corresponding to the first subset of precoding matrices, the value of "N1" may be 4, the value of "N2" may be 1, and the value of "O1" may be 4 or 2 or 1. For example, the value of "O2" may be 1. In some embodiments, corresponding to the first subset, In some embodiments, corresponding to the first subset, m and m' may be 0. In some embodiments, corresponding to the first subset, l' = l + k1. In some embodiments, corresponding to the first subset, l may be a non-negative integer, 0 ≤ l ≤ O1N1. For example, l may be at least one of {0, 2, 4, 6}. Again, for example, l may be at least one of {0, 1, 2, 3}. Again, for example, l may be 0 or 1. Again, for example, l may be 0 or 2. In some embodiments, the number of precoding matrices in the first subset corresponding to layer 1 may be 32 or 16 or 8 or 4 or 2.

[0327] In some embodiments, there may be a second subset of precoding matrices corresponding to layer 1, and corresponding to the second subset of precoding matrices, the value of "N1" may be 2, the value of "N2" may be 2, and the value of "O1" may be 4 or 2 or 1. For example, the value of "O2" may be 4 or 2 or 1. In some embodiments, corresponding to the second subset, In some embodiments, corresponding to the second subset, l may be a non-negative integer, 0 ≤ l ≤ O1N1. For example, l may be at least one of {0, 2, 4, 6}. Again, for example, l may be at least one of {0, 1, 2, 3}. Again, for example, l may be 0 or 1. Again, for example, l may be 0 or 2. In some embodiments, corresponding to the second subset, m may be a non-negative integer. For example, 0 ≤ m ≤ O2N2. Again, for example, m may be at least one of {0, 2, 4, 6}. Again, for example, m may be at least one of {0, 1, 2, 3}. Again, for example, m may be 0 or 1. Again, for example, m may be 0. In some embodiments, the number of precoding matrices in the second subset corresponding to layer 1 may be 256 or 128 or 32 or 16 or 8 or 4 or 2.

[0328] In some embodiments, if the terminal device 110 is indicated to have layer 1, there may be a third subset of precoding matrices. In some embodiments, there may be a third vector In some embodiments, In some embodiments, N1 = 2 and N2 = 1, In some embodiments, l can be a non - negative integer. For example, 0 ≤ l ≤ O1N1. For another example, l can be at least one of {0, 2}. For another example, l can be at least one of {0, 1, 2, 3}. For another example, l can be 0 or 1. In some embodiments, the value of p1 can be at least one of {0, 1, 2, 3} or {0, 1} or {0, 2}. In some embodiments, the value of p1 can be 0. In some embodiments, the value of n can be at least one of {0, 1, 2, 3} or {0, 1} or {0, 2}. In some embodiments, the value of n can be 0.

[0329] In some embodiments, there can be a third subset of precoding matrices corresponding to layer 1, and corresponding to the third subset of precoding matrices, the value of "N1" can be 2, the value of "N2" can be 1, and the value of "O1" can be 4 or 2 or 1. For example, the value of "O2" can be 1. In some embodiments, corresponding to the third subset, In some embodiments, corresponding to the third subset, l can be a non - negative integer, 0 ≤ l ≤ O1N1. For example, l can be at least one of {0, 1, 2, 3}. For another example, l can be 0 or 1. For another example, l can be 0 or 2. In some embodiments, the number of precoding matrices in the third subset corresponding to layer 1 can be 256 or 128 or 64 or 32 or 16 or 8 or 4 or 2.

[0330] In some embodiments, the terminal device 110 can be indicated to have 1 layer, and the precoding matrices in the third subset of precoding matrices corresponding to layer 1 can be represented as: In some embodiments, can be In some embodiments, p can be p1.

[0331] In some embodiments, if the terminal device 110 is indicated to have 1 layer, then there can be a fourth subset of precoding matrices. In some embodiments, in some embodiments, there can be a fifth vector In some embodiments, In some embodiments, N1 = 2 and N2 = 1, In some embodiments, l can be a non - negative integer. For example, 0 ≤ l ≤ O1N1. For another example, l can be at least one of {0, 2}. For another example, l can be at least one of {0, 1, 2, 3}. For another example, l can be 0 or 1. In some embodiments, the value of p1 can be at least one of {0, 1, 2, 3} or {0, 1} or {0, 2}. In some embodiments, the value of p1 can be 0. In some embodiments, the value of n0 can be at least one of {0, 1, 2, 3} or {0, 1} or {0, 2}. In some embodiments, the value of n0 can be 0. In some embodiments, the value of n1 can be at least one of {0, 1, 2, 3} or {0, 1} or {0, 2}. In some embodiments, the value of n1 can be 0. In some embodiments, the value of n2 can be at least one of {0, 1, 2, 3} or {0, 1} or {0, 2}. In some embodiments, the value of n2 can be 0.

[0332] In some embodiments, there can be a fourth subset of precoding matrices corresponding to layer 1, and corresponding to the fourth subset of precoding matrices, the value of "N1" can be 2, the value of "N2" can be 1, and the value of "O1" can be 4 or 2 or 1. For example, the value of "O2" can be 1. In some embodiments, corresponding to the fourth subset, In some embodiments, corresponding to the fourth subset, l can be a non - negative integer, 0 ≤ l ≤ O1N1. For example, l can be at least one of {0, 1, 2, 3}. For another example, l can be 0 or 1. For another example, l can be 0 or 2. In some embodiments, the number of precoding matrices in the fourth subset corresponding to layer 1 can be 256 or 128 or 64 or 32 or 16 or 8 or 4 or 2.

[0333] In some embodiments, the terminal device 110 can be indicated as having 1 layer, and the precoding matrices in the fourth subset of precoding matrices corresponding to layer 1 can be represented as: In some embodiments, can be In some embodiments, p can be [p1 p2]. In some embodiments, n can be [n0 n1 n2].

[0334] In some embodiments, if the terminal device 110 is indicated to have one layer, there may be a second set of precoding matrices (e.g., a second set of partially coherent precoding matrices) corresponding to one layer. For example, if the terminal device 110 has eight antenna ports, or if the PUSCH transmission of the terminal device 110 is associated with eight antenna ports, or if the PUSCH transmission of the terminal device 110 is associated with an SRS having eight ports, then four antenna ports (e.g., a first set of four ports) may be coherent, and the other four antenna ports (e.g., a second set of four ports) may be coherent. For example, the first set of four ports may be non - coherent with the second set of four ports. In some embodiments, there may be a second set of precoding matrices (e.g., a second set of partially coherent precoding matrices) corresponding to two layers, e.g., denoted as "Set_p1_1", and the size of the partially coherent precoding matrix may be 1 by 8 or 8 by 1. In some embodiments, the precoding matrix may have one column or row. In some embodiments, there may be eight elements in a column or row of the precoding matrix. In some embodiments, for a column or row of the partially coherent precoding matrix, four of the eight elements in the partially coherent matrix may have non - zero values. And the other four elements in the partially coherent precoding matrix may have a value of 0. In some embodiments, in the precoding matrix, and in a column or row, the non - zero values may be mapped to four of the eight elements, and the other four elements are 0. For example, the indices idx_1 of the four elements with non - zero values, and idx_1 may be four values from {0, 1, 2, 3, 4, 5, 6, 7} or {1, 2, 3, 4, 5, 6, 7, 8}. In some embodiments, the four values of idx_1 may be based on the indices of four antenna ports in the first set or the second set. For example, idx_1 may be {0, 1, 2, 3} or {0, 2, 4, 6} or {1, 2, 3, 4} or {1, 3, 5, 7} or {4, 5, 6, 7} or {1, 3, 5, 7} or {5, 6, 7, 8} or {2, 4, 6, 8}.

[0335] In some embodiments, there may be two sets of vectors of length 4, and each set may include 4 vectors of length 4. In some embodiments, the values in the vectors of length 4 may be applied to map to 4 non-zero values among 4 elements in a column or a row of a precoding matrix. For example, the first set of vectors of length 4 may be {[1; 1; 1; 1], [1; -1; 1; -1], [1; 1; -1; -1], [1; -1; -1; 1]}. For another example, the second set of vectors of length 4 may be {[1; 1; j; j], [1; -1; j; -j], [1; 1; -j; -j], [1; -1; -j; j]}. In some embodiments, the 4 values in each vector in the first set or the second set may be mapped to 4 elements among 8 elements, and 0 may be mapped to the other 4 elements in a column or a row of the precoding matrix.

[0336] In some embodiments, an example of the precoding matrix in the second set of precoding matrices corresponding to layer 1 may be as follows: Or For example, rows or columns may be swapped. For example, rows or columns may be swapped. For example, each of [a1, a2, a3, a4] may be one of the vectors of length 4 in the first set of vectors of length 4 or the second set of vectors of length 4. For example, [a1, a2, a3, a4] may be one of [1; 1; 1; 1], [1; -1; 1; -1], [1; 1; -1; -1], [1; -1; -1; 1], [1; 1; j; j], [1; -1; j; -j], [1; 1; -j; -j], and [1; -1; -j; j].

[0337] In some embodiments, s1 may be a positive integer. For example, 1 ≤ s1 ≤ 64. For example, s1 may be 64 or 32 or 16 or 8 or 4 or 2 or 1.

[0338] In some embodiments, if the terminal device 110 is indicated to have one layer, there may be a third set of precoding matrices (e.g., a third set of partial interference precoding matrices) corresponding to one layer. For example, the structure of 8 ports may be 2+2+2+2, which means there are 4 groups, each group including 2 antenna ports, and within each group, the 2 antenna ports may be coherent. For example, between groups, the antenna ports may not be coherent. In some embodiments, there may be a third set of precoding matrices (e.g., a third set of partial interference precoding matrices), such as denoted as "Set_p1_2", and the size of the precoding matrix may be 1 by 8 or 8 by 1. In some embodiments, the precoding matrix may have 1 column or row. In some embodiments, there may be 8 elements in the column or row of the precoding matrix. In some embodiments, for the column or row of the precoding matrix, 2 of the 8 elements in the precoding matrix may have non-zero values. And the other 6 elements in the precoding matrix may have the value 0. In some embodiments, in the column or row of the precoding matrix, the ...

Claims

1. A communication method, comprising: at a terminal device, receiving first information associated with at least one first precoding matrix from a network device; receiving second information associated with a set of phase offsets for the at least one first precoding matrix from the network device; determining a second precoding matrix based on the at least one first precoding matrix and the second information; and performing a transmission to the network device on a physical uplink shared channel (PUSCH) based on the second precoding matrix.

2. The method according to claim 1, wherein the first information is included in a downlink control information (DCI) field, and the DCI field indicates an index of the at least one first precoding matrix.

3. The method according to claim 1 or 2, wherein the at least one first precoding matrix is a discrete Fourier transform (DFT)-based precoding matrix, or wherein the at least one first precoding matrix is a first downlink type precoding matrix.

4. The method according to any one of claims 1 to 3, wherein the phase offsets in the set of phase offsets are between antennas of the terminal device.

5. The method according to any one of claims 1 to 4, wherein the second information is transmitted via medium access control (MAC) signaling, or wherein the second information is transmitted via radio resource control (RRC) signaling.

6. The method according to any one of claims 1 to 5, wherein the set of phase offsets is the same for each layer of each first precoding matrix in the at least one first precoding matrix, or wherein the set of phase offsets is layer common.

7. The method according to any one of claims 1 to 6, wherein the number of phase offsets in the set of phase offsets is less than the number of rows or columns in each first precoding matrix in the at least one first precoding matrix, or wherein the number of phase offsets is one of: 7, 6, 3, or 2.

8. The method according to any one of claims 1 to 7, wherein the phase offset in the set of phase offsets is at least one of {1, j, -1, -j}, or wherein the phase offset in the set of phase offsets is e j*2π*m / M , and where M is at least one of {4, 8, 16}, and m is an integer from 0 to M - 1.

9. A communication method, comprising: at a terminal device, receiving first information associated with a subset of precoding matrices from a network device; receiving second information from the network device indicating a precoding matrix in the subset of precoding matrices, wherein a bit size for indicating the second information is based on the number of precoding matrices in the subset of first precoding matrices; and performing a transmission to the network device on a physical uplink shared channel (PUSCH) based on the indicated precoding matrix.

10. The method according to claim 9, wherein the precoding matrices in the subset are based on a plurality of discrete Fourier transform (DFT)-based precoding matrices, or wherein the precoding matrices in the subset are based on a first downlink type precoding matrix and a set of phase offsets between antennas of the terminal device.

11. A communication method, comprising: At a terminal device, downlink control information including a first field and a second field is received from a network device, where the first field indicates a first precoding matrix, and the second field indicates a parameter based on the first field; A second precoding matrix is determined based on the first precoding matrix and the parameter; and Based on the second precoding matrix, a transmission to the network device is performed.

12. The method according to claim 11, wherein the terminal device is configured with a sounding reference signal (SRS) resource set for 8-antenna transmission, where the SRS resource set includes at least one SRS resource, and where each SRS resource in the SRS resource set includes 8 ports.

13. The method according to claim 11, further comprising at least one of the following: If the first precoding matrix is a full-phase precoding matrix, or the value of the first field is within a first range, the second field indicates at least one phase offset between antennas; If the first precoding matrix is a partial-phase precoding matrix, or the value of the first field is within at least one of a second range or a third range, the second field indicates an index of a set of antennas, and the first precoding matrix is mapped to a row or a column corresponding to the set of antennas; or If the first precoding matrix is a non-phase precoding matrix, or the value of the first field is within a fourth range, the second field indicates an index of a set of antennas, and the first precoding matrix is mapped to a row or a column corresponding to the set of antennas.

14. The method according to claim 13, further comprising at least one of the following: If the first precoding matrix is a partial-phase precoding matrix or a non-phase precoding matrix of length 2, the set of antennas is from 4 sets of antennas, and each set includes 2 antennas; or If the first precoding matrix is a partial-phase precoding matrix or a non-phase precoding matrix of length 4, the set of antennas is from 2 sets of antennas, and each set includes 4 antennas.

15. A communication method, comprising: At a network device, first information associated with at least one first precoding matrix is transmitted to a terminal device; Second information associated with a set of phase offsets for the at least one first precoding matrix is transmitted to the terminal device; and A transmission on a physical uplink shared channel (PUSCH) is received from the terminal device, where the transmission is based on a second precoding matrix, and the second precoding matrix is determined based on the at least one first precoding matrix and the second information.

16. A communication method, comprising: At a network device, first information associated with a subset of precoding matrices is transmitted to a terminal device; Second information indicating a precoding matrix in the subset of precoding matrices is transmitted to the terminal device, where the bit size for indicating the second information is based on the number of precoding matrices in the subset of the first precoding matrix; and A transmission on a physical uplink shared channel (PUSCH) is received from the terminal device, where the transmission is based on the indicated precoding matrix.

17. A communication method, comprising: at a network device, transmitting downlink control information including a first field and a second field to a terminal device, where the first field indicates a first precoding matrix, and the second field indicates a parameter based on the first field; and receiving, from the terminal device, a transmission based on a second precoding matrix, the second precoding matrix being based on the first precoding matrix and the parameter.

18. A terminal device, comprising: a processor; and a memory coupled to the processor and storing instructions thereon, the instructions, when executed by the processor, causing the terminal device to perform operations including the method according to any one of claims 1 to 14.

19. A network device, comprising: a processor; and a memory coupled to the processor and storing instructions thereon, the instructions, when executed by the processor, causing the network device to perform operations including the method according to any one of claims 15 to 17.

20. A computer-readable medium having instructions stored thereon, the instructions, when executed on at least one processor, causing the at least one processor to perform the method according to any one of claims 1 to 14 or any one of claims 15 to 17.

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