WO2024092470A1 - Procédé, dispositif et support d'enregistrement informatique de communication - Google Patents

Procédé, dispositif et support d'enregistrement informatique de communication Download PDF

Info

Publication number
WO2024092470A1
WO2024092470A1 PCT/CN2022/128807 CN2022128807W WO2024092470A1 WO 2024092470 A1 WO2024092470 A1 WO 2024092470A1 CN 2022128807 W CN2022128807 W CN 2022128807W WO 2024092470 A1 WO2024092470 A1 WO 2024092470A1
Authority
WO
WIPO (PCT)
Prior art keywords
antennas
precoding matrix
coherent
idx
columns
Prior art date
Application number
PCT/CN2022/128807
Other languages
English (en)
Inventor
Yukai GAO
Peng Guan
Gang Wang
Original Assignee
Nec Corporation
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Nec Corporation filed Critical Nec Corporation
Priority to PCT/CN2022/128807 priority Critical patent/WO2024092470A1/fr
Publication of WO2024092470A1 publication Critical patent/WO2024092470A1/fr

Links

Images

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L5/00—Arrangements affording multiple use of the transmission path
    • H04L5/0001—Arrangements for dividing the transmission path
    • H04L5/0014—Three-dimensional division
    • H04L5/0023—Time-frequency-space
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L5/00—Arrangements affording multiple use of the transmission path
    • H04L5/003—Arrangements for allocating sub-channels of the transmission path
    • H04L5/0053—Allocation of signaling, i.e. of overhead other than pilot signals

Definitions

  • Embodiments of the present disclosure generally relate to the field of telecommunication, and in particular, to methods, devices and computer storage media of communication for determining an uplink transmission codebook.
  • MIMO multi-input multi-output
  • a plurality of antennas at a transmitter and/or receiver can be used to achieve array and diversity gain instead of capacity gain.
  • a same symbol weighted by a complex-valued scale factor is sent from each transmit antenna so that the input covariance matrix has unit rank. This scheme is referred to as beamforming.
  • precoding is used for multi-layer beamforming in order to maximize the throughput of a multi-antenna system.
  • Precoding is a generalized beamforming scheme to support multi-layer transmission in a MIMO system. Using precoding, multiple streams are transmitted from the transmit antennas with independent and appropriate weighting per antenna such that the throughput is maximized at the receiver output.
  • embodiments of the present disclosure provide methods, devices and computer storage media for communication.
  • a communication method comprises: receiving, at a terminal device, from a network device, first information associated with at least one first precoding matrix; receiving, from the network device, second information associated with a set of phase offsets for the at least one first precoding matrix; 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.
  • PUSCH physical uplink shared channel
  • a communication method comprises: receiving, at a terminal device, from a network device, first information associated with a subset of precoding matrixes; receiving, from the network device, second information indicating a precoding matrix in the subset of precoding matrixes, wherein a bit size for indicating the second information is based on the number of precoding matrixes in the subset of first precoding matrixes; and performing a transmission to the network device on a physical uplink shared channel (PUSCH) based on the indicated precoding matrix.
  • PUSCH physical uplink shared channel
  • a communication method comprises: receiving, at a terminal device, from a network device, downlink control information comprising a first field and a second field, wherein the first field indicates a first precoding matrix and the second field indicates a parameter that is 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.
  • a communication method comprises: transmitting, at a network device, to a terminal device, first information associated with at least one first precoding matrix; transmitting, to the terminal device, second information associated with a set of phase offsets for the at least one first precoding matrix; and receiving, from the terminal device, a transmission on a physical uplink shared channel (PUSCH) , wherein the transmission is based on a second precoding matrix which is determined based on the at least one first precoding matrix and the second information.
  • PUSCH physical uplink shared channel
  • a communication method comprises: transmitting, at a network device, to a terminal device, first information associated with a subset of precoding matrixes; transmitting, to the terminal device, second information indicating a precoding matrix in the subset of precoding matrixes, wherein a bit size for indicating the second information is based on the number of precoding matrixes in the subset of first precoding matrixes; and receiving, from the terminal device, a transmission on a physical uplink shared channel (PUSCH) , wherein the transmission is based on the indicated precoding matrix.
  • PUSCH physical uplink shared channel
  • a communication method comprises: transmitting, at a network device, to a terminal device, downlink control information comprising a first field and a second field, wherein the first field indicates a first precoding matrix and the second field indicates a parameter that is based on the first field; and receiving, from the terminal device, a transmission based on a second precoding matrix that is based on the first precoding matrix and the parameter.
  • a terminal device comprising at least one processor; and at least one memory coupled to the at least one processor and storing instructions thereon, the instructions, when executed by the at least one processor, causing the terminal device to perform the method according to the first, second, or third aspect.
  • a network device comprising at least one processor; and at least one memory coupled to the at least one processor and storing instructions thereon, the instructions, when executed by the at least one processor, causing the network device to perform the method according to the fourth, fifth, or sixth aspect.
  • a computer readable medium having instructions stored thereon, the instructions, when executed on at least one processor, causing the at least one processor to carry out the method according to the first, second, third, fourth, fifth, or sixth aspect.
  • FIG. 1 is a schematic diagram of a communication environment in which embodiments of the present disclosure can be implemented
  • FIG. 2 illustrates a signaling flow for communications according to some embodiments of the present disclosure
  • FIG. 3 illustrates a signaling flow for communications according to some embodiments of the present disclosure
  • FIG. 4 illustrates a signaling flow for communications according to some embodiments of the present disclosure
  • FIG. 5 illustrates a schematic diagram of downlink control information (DCI) according to some embodiments of the present disclosure
  • FIG. 6 is a flowchart of an example method in accordance with an embodiment of the present disclosure.
  • FIG. 7 is a flowchart of an example method in accordance with an embodiment of the present disclosure.
  • FIG. 8 is a flowchart of an example method in accordance with an embodiment of the present disclosure.
  • FIG. 9 is a flowchart of an example method in accordance with an embodiment of the present disclosure.
  • FIG. 10 is a flowchart of an example method in accordance with an embodiment of the present disclosure.
  • FIG. 11 is a flowchart of an example method in accordance with an embodiment of the present disclosure.
  • FIG. 12 is a simplified block diagram of a device that is suitable for implementing embodiments of the present disclosure.
  • terminal device refers to any device having wireless or wired communication capabilities.
  • the terminal device include, but not limited to, user equipment (UE) , personal computers, desktops, mobile phones, cellular phones, smart phones, personal digital assistants (PDAs) , portable computers, tablets, wearable devices, internet of things (IoT) devices, Ultra-reliable and Low Latency Communications (URLLC) devices, Internet of Everything (IoE) devices, machine type communication (MTC) devices, device on vehicle for V2X communication where X means pedestrian, vehicle, or infrastructure/network, devices for Integrated Access and Backhaul (IAB) , Space borne vehicles or Air borne vehicles in Non-terrestrial networks (NTN) including Satellites and High Altitude Platforms (HAPs) encompassing Unmanned Aircraft Systems (UAS) , eXtended Reality (XR) devices including different types of realities such as Augmented Reality (AR) , Mixed Reality (MR) and Virtual Reality (VR) , the unmanned aerial vehicle (UAV)
  • UE user equipment
  • the ‘terminal device’ can further has ‘multicast/broadcast’ feature, to support public safety and mission critical, V2X applications, transparent IPv4/IPv6 multicast delivery, IPTV, smart TV, radio services, software delivery over wireless, group communications and IoT applications. It may also incorporate one or multiple Subscriber Identity Module (SIM) as known as Multi-SIM.
  • SIM Subscriber Identity Module
  • the term “terminal device” can be used interchangeably with a UE, a mobile station, a subscriber station, a mobile terminal, a user terminal or a wireless device.
  • network device refers to a device which is capable of providing or hosting a cell or coverage where terminal devices can communicate.
  • a network device include, but not limited to, a Node B (NodeB or NB) , an evolved NodeB (eNodeB or eNB) , a next generation NodeB (gNB) , a transmission reception point (TRP) , a remote radio unit (RRU) , a radio head (RH) , a remote radio head (RRH) , an IAB node, a low power node such as a femto node, a pico node, a reconfigurable intelligent surface (RIS) , and the like.
  • NodeB Node B
  • eNodeB or eNB evolved NodeB
  • gNB next generation NodeB
  • TRP transmission reception point
  • RRU remote radio unit
  • RH radio head
  • RRH remote radio head
  • IAB node a low power node such as a fe
  • the terminal device or the network device may have Artificial intelligence (AI) or Machine learning capability. It generally includes a model which has been trained from numerous collected data for a specific function, and can be used to predict some information.
  • AI Artificial intelligence
  • Machine learning capability it generally includes a model which has been trained from numerous collected data for a specific function, and can be used to predict some information.
  • the terminal or the network device may work on several frequency ranges, e.g. FR1 (410 MHz to 7125 MHz) , FR2 (24.25GHz to 71GHz) , FR2-2 (52.6GHz to 71GHz) , frequency band larger than 100GHz as well as Tera Hertz (THz) . It can further work on licensed/unlicensed/shared spectrum.
  • the terminal device may have more than one connection with the network devices under Multi-Radio Dual Connectivity (MR-DC) application scenario.
  • MR-DC Multi-Radio Dual Connectivity
  • the terminal device or the network device can work on full duplex, flexible duplex and cross division duplex modes.
  • test equipment e.g. signal generator, signal analyzer, spectrum analyzer, network analyzer, test terminal device, test network device, channel emulator.
  • the terminal device may be connected with 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 one may be a secondary node.
  • the first network device and the second network device may use different radio access technologies (RATs) .
  • the first network device may be a first RAT device and the second network device may be a second RAT device.
  • the first RAT device is eNB and the second RAT device is gNB.
  • Information related with different RATs may be transmitted to the terminal device from at least one of the first network device or the second network device.
  • first information may be transmitted to the terminal device from the first network device and second information may be transmitted to the terminal device from the second network device directly or via the first network device.
  • information related with configuration for the terminal device configured by the second network device may be transmitted from the second network device via the first network device.
  • Information related with reconfiguration for the terminal device configured by the second network device may be transmitted to the terminal device from the second network device directly or via the first network device.
  • the singular forms ‘a’ , ‘an’ and ‘the’ are intended to include the plural forms as well, unless the context clearly indicates otherwise.
  • the term ‘includes’ and its variants are to be read as open terms that mean ‘includes, but is not limited to. ’
  • the term ‘based on’ is to be read as ‘at least in part based on. ’
  • the term ‘one embodiment’ and ‘an embodiment’ are to be read as ‘at least one embodiment. ’
  • the term ‘another embodiment’ is to be read as ‘at least one other embodiment. ’
  • the terms ‘first, ’ ‘second, ’ and the like may refer to different or same objects. Other definitions, explicit and implicit, may be included below.
  • values, procedures, or apparatus are referred to as ‘best, ’ ‘lowest, ’ ‘highest, ’ ‘minimum, ’ ‘maximum, ’ or the like. It will be appreciated that such descriptions are intended to indicate that a selection among many used functional alternatives can be made, and such selections need not be better, smaller, higher, or otherwise preferable to other selections.
  • transmission occasions In the context of the present application, the terms “transmission occasions” , “reception occasions” , “repetitions” , “transmission” , “reception” , “PDSCH transmission occasions” , “PDSCH repetitions” , “PUSCH transmission occasions” , “PUSCH repetitions” , “PUCCH occasions” , “PUCCH repetitions” , “repeated transmissions” , “repeated receptions” , “PDSCH transmissions” , “PDSCH receptions” , “PUSCH transmissions” , “PUSCH receptions” , “PUCCH transmissions” , “PUCCH receptions” , “RS transmission” , “RS reception” , “communication” , “transmissions” and “receptions” can be used interchangeably.
  • TCI state , “set of QCL parameter (s) ” , “QCL parameter (s) ” , “QCL assumption” and “QCL configuration” can be used interchangeably.
  • TCI field , “TCI state field” , and “transmission configuration indication” can be used interchangeably.
  • 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” , “multi-chance” and “PDCCH repetition”
  • 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” , “multi-chance” and “PDCCH repetition”
  • the terms “PDCCH repetitions” , “repeated PDCCHs” , “repeated PDCCH signals” , “PDCCH candidates configured for same scheduling” , “PDCCH” , “PDCCH candidates” and “linked PDCCH candidates” can be used interchangeably.
  • the terms “DCI” and “DCI format” can be used interchangeably.
  • the embodiments in this disclosure can be applied to PDSCH and PUSCH scheduling, and in the following, PDSCH scheduling is described as examples.
  • the embodiments in this disclosure can be applied to PUSCH by replacing “transmit” to “receive” and/or “receive” to “transmit” .
  • the terms “PDSCH” and “PUSCH” can be used interchangeably.
  • the terms “transmit” and “receive” can be used interchangeably.
  • subset of CORESETs may be used interchangeably.
  • subset of TCI states may be used interchangeably.
  • subset of PUCCHs may be used interchangeably.
  • precoding matrix may be used interchangeably.
  • precoding may be used interchangeably.
  • anticoding may be used interchangeably.
  • antienna and “antenna port” may be used interchangeably.
  • transmission may be used interchangeably.
  • precoding is a generalized beamforming scheme to support multi-layer transmission in a MIMO system.
  • Precoding is a technique that exploits transmit diversity by weighting the information stream, i.e. the transmitter sends the coded information to the receiver to achieve pre-knowledge of the channel.
  • multiple streams are transmitted from the transmit antennas with independent and appropriate weighting per antenna such that the throughput is maximized at the receiver output.
  • precoding matrix and “precoder” may be used interchangeably hereinafter.
  • uplink transmission with 8 antenna ports can support more than 4 layers.
  • TX transmission
  • UL uplink
  • timing alignment error (TAE) or phase error between antennas of UE may be randomized (for different UEs) but fixed (invariant in time) for a given UE (based on QC) .
  • TAE timing alignment error
  • phase difference across antennas is in unit of pi/2, still can not meet the randomized phase error (-pi, pi) .
  • Embodiments of the present disclosure provide a solution on uplink precoding matrixes.
  • 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.
  • the terminal device determines a second precoding matrix based on the at least one first precoding matrix and the phase offset information.
  • the terminal device performs a transmission to the network device on a PUSCH based on the second precoding matrix. In this way, the overhead can be reduced and the TAE can be solved.
  • FIG. 1 illustrates a schematic diagram of an example communication network 100 in which some embodiments of the present disclosure can be implemented.
  • 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.
  • the terminal device 110 is located in the cell 121 and is served by the network device 120.
  • the communication network 100 may include any suitable number of network devices and/or terminal devices and/or cells adapted for implementing implementations of the present disclosure.
  • 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., Uu interface) .
  • the wireless communication channel may comprise 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) .
  • PUCCH physical uplink control channel
  • PUSCH physical uplink shared channel
  • PRACH physical random-access channel
  • PDCCH physical downlink control channel
  • PDSCH physical downlink shared channel
  • PBCH physical broadcast channel
  • any other suitable channels are also feasible.
  • the communications in the communication network 100 may conform to any suitable standards 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) and the like.
  • GSM Global System for Mobile Communications
  • LTE Long Term Evolution
  • LTE-Evolution LTE-Advanced
  • NR New Radio
  • WCDMA Wideband Code Division Multiple Access
  • CDMA Code Division Multiple Access
  • GERAN GSM EDGE Radio Access Network
  • MTC Machine Type Communication
  • Examples of the communication protocols include, but not limited to, the first generation (1G) , the second generation (2G) , 2.5G, 2.75G, the third generation (3G) , the fourth generation (4G) , 4.5G, the fifth generation (5G) communication protocols, 5.5G, 5G-Advanced networks, or the sixth generation (6G) networks.
  • the network device 120 may transmit information to the terminal device 110.
  • the information may indicate that a PUSCH is scheduled associated with 8 antenna ports. For example, total number of antenna ports for the PUSCH transmission may be 8.
  • the information may indicate that the PUSCH is scheduled associated with a sounding reference signal (SRS) with 8 antenna ports. In other words, the total number of antenna ports of a SRS associated with the PUSCH transmission is 8.
  • the information may be transmitted in a SRS configuration.
  • the terminal device 110 may support 1 antenna port or 2 antenna ports or 4 antenna ports or 8 antenna ports.
  • SC-FDMA single carrier frequency division multiple access
  • OFDM there may be at least one of full coherent, partial coherent and non-coherent (antenna selection) codebook.
  • rank indicator (RI) and precoding matrix indicator (PMI) are jointly encoded, and different numbers of layers (RI values) may be indicated in same table/field.
  • RI and SRS resource indication are jointly encoded.
  • number of demodulation reference signal (DMRS) ports is determined based on the number of layers, and the antenna port field (DMRS port) only indicates DMRS port index (es) .
  • slot refers to a dynamic scheduling unit.
  • One slot comprises a predetermined number of symbols.
  • the number of symbols in one slot may be 12 or 14.
  • the term “sub-slot” may refer to a number of symbols.
  • the number of symbols in one sub-slot may be 1, 2, 4, 7, 14.
  • the sub-slot may comprise fewer symbols than one slot.
  • the slot used herein may refer to a normal slot which comprises a predetermined number of symbols and also refer to a sub-slot which comprises fewer symbols than the predetermined number of symbols.
  • the terminal device 110 may be configured or indicated with a number of layers (e.g. represented as v_ri) for the PUSCH transmission.
  • the number of layers v_ri may be at least one of ⁇ 1, 2, 3, 4, 5, 6, 7, 8 ⁇ .
  • the terminal device 110 may be configured or indicated with a precoding matrix for the PUSCH transmission.
  • the size of the precoding matrix may be 8*v_ri or v_ri*8.
  • the terminal device 110 may transmit at least one capability information to the network device 120.
  • the at least one capability information may indicate at least one of: supporting uplink transmission with 8 antennas or 8 antenna ports, supporting PUSCH transmission with 8 antennas or 8 antenna ports, and a capability of precoding matrix supported by the terminal device 110.
  • the capability information of precoding matrix may indicate a type of precoding matrix supported by the terminal device 110.
  • the capability information of precoding matrix may comprise at least one of: supporting at least one full coherent of 8 transmission (Tx) precoder, supporting at least one partial coherent of 8 Tx precoder, supporting at least one first full coherent of 8 Tx precoder, supporting at least one second full coherent of 8 Tx precoder, supporting at least one first partial coherent of 8 Tx precoder, supporting at least one second partial coherent of 8 Tx precoder, and supporting at least one non coherent of 8 Tx precoder.
  • the 8 antennas may comprise two groups, and each group may comprise 4 antennas, and the 4 antennas in one group may be coherent to each other. For example, antennas in different groups may not be coherent or may be non-coherent.
  • the 8 antennas may comprise four groups, and each group may comprise 2 antennas, and the 2 antennas in one group may be coherent to each other.
  • antennas in different groups may not be coherent or may be non-coherent.
  • the 8 antennas may not be coherent or may be non coherent to each other.
  • the at least one precoder for 8 Tx may comprise at least one of: at least one full coherent 8 Tx precoder, at least one first full coherent 8 Tx precoder, at least one second full coherent 8 Tx precoder, at least one partial coherent 8 Tx precoder, at least one first partial coherent 8 Tx precoder, at least one second partial coherent 8 Tx precoder and at least one non coherent 8 Tx precoder.
  • the size of the at least one precoder may be 8*v_ri or v_ri*8.
  • each antenna group comprises 4 antennas.
  • each antenna group comprises 2 antennas.
  • each one of the index of an element or each one of the element in one of the column or one of the row of each of the at least one precoder may be associated with the index of one antenna of the 8 antennas.
  • the first element or the index of the first element in one of the column or one of the row of each of the at least one precoder may be associated with AP0.
  • the second element or the index of the second element in one of the column or one of the row of each of the at least one precoder may be associated with AP1.
  • the third element or the index of the third element in one of the column or one of the row of each of the at least one precoder may be associated with AP2.
  • the fourth element or the index of the fourth element in one of the column or one of the row of each of the at least one precoder may be associated with AP3.
  • the fifth element or the index of the fifth element in one of the column or one of the row of each of the at least one precoder may be associated with AP4.
  • the sixth element or the index of the sixth element in one of the column or one of the row of each of the at least one precoder may be associated with AP5.
  • the seventh element or the index of the seventh element in one of the column or one of the row of each of the at least one precoder may be associated with AP6.
  • the eighth element or the index of the eighth element in one of the column or one of the row of each of the at least one precoder may be associated with AP7.
  • the terminal device 110 may support 1 antenna port or 2 antenna ports or 4 antenna ports or 8 antenna ports.
  • SC-FDMA single carrier frequency division multiple access
  • OFDM there may be at least one of full coherent, partial coherent and non-coherent (antenna selection) codebook.
  • rank indicator (RI) and precoding matrix indicator (PMI) are jointly encoded, and different numbers of layers (RI values) may be indicated in same table/field.
  • RI and SRS resource indication are jointly encoded.
  • number of demodulation reference signal (DMRS) ports is determined based on the number of layers, and the antenna port field (DMRS port) only indicates DMRS port index (es) .
  • the terminal device 120 may indicate or report the at least one capability that supporting at least one full coherent 8 Tx precoder. In some embodiments, the terminal device 120 may be configured with the at least one full coherent 8 Tx precoder. In some embodiments, the terminal device 120 may be configured with the at least one full coherent 8 Tx precoder (or at least one first full coherent 8 Tx precoder or at least one second full coherent 8 Tx precoder) and at least one partial coherent 8 Tx precoder and/or at least one non coherent 8 Tx precoder.
  • the terminal device 120 may be configured with the at least one full coherent 8 Tx precoder (or at least one first full coherent 8 Tx precoder or at least one second full coherent 8 Tx precoder) and at least one first partial coherent 8 Tx precoder and at least one second partial coherent 8 Tx precoder and/or at least one non coherent 8 Tx precoder. In some embodiments, the terminal device 120 may be configured with the at least one full coherent 8 Tx precoder (or at least one first full coherent 8 Tx precoder or at least one second full coherent 8 Tx precoder) and at least one first partial coherent 8 Tx precoder and/or at least one non coherent 8 Tx precoder.
  • the terminal device 120 may be configured with the at least one full coherent 8 Tx precoder (or at least one first full coherent 8 Tx precoder or at least one second full coherent 8 Tx precoder) and at least one second partial coherent 8 Tx precoder and/or at least one non coherent 8 Tx precoder.
  • the terminal device 120 may indicate or report the at least one capability that supporting at least one first full coherent 8 Tx precoder. In some embodiments, the terminal device 120 may be configured with the at least one first full coherent 8 Tx precoder. In some embodiments, the terminal device 120 may be configured with the at least one first full coherent 8 Tx precoder and at least one partial coherent 8 Tx precoder and/or at least one non coherent 8 Tx precoder. In some embodiments, the terminal device 120 may be configured with the at least one first full coherent 8 Tx precoder and at least one first partial coherent 8 Tx precoder and at least one second partial coherent 8 Tx precoder and/or at least one non coherent 8 Tx precoder.
  • the terminal device 120 may be configured with the at least one first full coherent 8 Tx precoder and at least one first partial coherent 8 Tx precoder and/or at least one non coherent 8 Tx precoder. In some embodiments, the terminal device 120 may be configured with the at least one first full coherent 8 Tx precoder and at least one second partial coherent 8 Tx precoder and/or at least one non coherent 8 Tx precoder.
  • the terminal device 120 may indicate or report the at least one capability that supporting at least one second full coherent 8 Tx precoder. In some embodiments, the terminal device 120 may be configured with the at least one second full coherent 8 Tx precoder. In some embodiments, the terminal device 120 may be configured with the at least one second full coherent 8 Tx precoder and at least one partial coherent 8 Tx precoder and/or at least one non coherent 8 Tx precoder. In some embodiments, the terminal device 120 may be configured with the at least one second full coherent 8 Tx precoder and at least one first partial coherent 8 Tx precoder and at least one second partial coherent 8 Tx precoder and/or at least one non coherent 8 Tx precoder.
  • the terminal device 120 may be configured with the at least one second full coherent 8 Tx precoder and at least one first partial coherent 8 Tx precoder and/or at least one non coherent 8 Tx precoder. In some embodiments, the terminal device 120 may be configured with the at least one second full coherent 8 Tx precoder and at least one second partial coherent 8 Tx precoder and/or at least one non coherent 8 Tx precoder.
  • the terminal device 120 may indicate or report the at least one capability that supporting at least one partial coherent 8 Tx precoder. In some embodiments, the terminal device 120 may be configured with the at least one partial coherent 8 Tx precoder. In some embodiments, the terminal device 120 may be configured with the at least one partial coherent 8 Tx precoder and/or at least one non coherent 8 Tx precoder. In some embodiments, the terminal device 120 may be configured with the at least one first partial coherent 8 Tx precoder and at least one second partial coherent 8 Tx precoder and/or at least one non coherent 8 Tx precoder.
  • the terminal device 120 may be configured with the at least one first partial coherent 8 Tx precoder and/or at least one non coherent 8 Tx precoder. In some embodiments, the terminal device 120 may be configured with the at least one second partial coherent 8 Tx precoder and/or at least one non coherent 8 Tx precoder.
  • the terminal device 120 may indicate or report the at least one capability that supporting at least one first partial coherent 8 Tx precoder. In some embodiments, the terminal device 120 may be configured with the at least one first partial coherent 8 Tx precoder. In some embodiments, the terminal device 120 may be configured with the at least one first partial coherent 8 Tx precoder and at least one second partial coherent 8 Tx precoder. In some embodiments, the terminal device 120 may be configured with the at least one first partial coherent 8 Tx precoder and/or at least one non coherent 8 Tx precoder.
  • the terminal device 120 may be configured with the at least one first partial coherent 8 Tx precoder and at least one second partial coherent 8 Tx precoder and/or at least one non coherent 8 Tx precoder. In some embodiments, the terminal device 120 may be configured with the at least one second partial coherent 8 Tx precoder and/or at least one non coherent 8 Tx precoder.
  • the terminal device 120 may indicate or report the at least one capability that supporting at least one second partial coherent 8 Tx precoder. In some embodiments, the terminal device 120 may be configured with the at least one second partial coherent 8 Tx precoder. In some embodiments, the terminal device 120 may be configured with the at least one first partial coherent 8 Tx precoder and at least one second partial coherent 8 Tx precoder. In some embodiments, the terminal device 120 may be configured with the at least one first partial coherent 8 Tx precoder and/or at least one non coherent 8 Tx precoder.
  • the terminal device 120 may be configured with the at least one first partial coherent 8 Tx precoder and at least one second partial coherent 8 Tx precoder and/or at least one non coherent 8 Tx precoder. In some embodiments, the terminal device 120 may be configured with the at least one second partial coherent 8 Tx precoder and/or at least one non coherent 8 Tx precoder.
  • the terminal device 120 may indicate or report the at least one capability that supporting at least one non coherent 8 Tx precoder. In some embodiments, the terminal device 120 may be configured with the at least one non coherent 8 Tx precoder.
  • the 8 elements in each column or in each row of the precoding matrix may be non-zero value.
  • the value may be at least one of ⁇ 1, -1, j, -j ⁇ or at least one of ⁇ 1, e j*2 ⁇ /8 , e j*2*2 ⁇ /8 , e j*3*2 ⁇ /8 , e j*4*2 ⁇ /8 , e j*5*2 ⁇ /8 , e j*6*2 ⁇ /8 , e j*7*2 ⁇ /8 ⁇ .
  • each one of the partial coherent 8 Tx precoders and/or each one of the first partial coherent 8 Tx precoders for the 8 elements in each column or in each row of the precoding matrix, there may be 4 elements with non-zero values, and the other 4 elements are with value 0.
  • the value for the 4 elements with non-zero values may be at least one of ⁇ 1, -1, j, -j ⁇ or at least one of ⁇ 1, e j*2 ⁇ /8 , e j*2*2 ⁇ /8 , e j*3*2 ⁇ /8 , e j*4*2 ⁇ /8 , e j*5*2 ⁇ /8 , e j*6*2 ⁇ /8 , e j*7*2 ⁇ /8 ⁇ .
  • each one of the partial coherent 8 Tx precoders and/or each one of the second partial coherent 8 Tx precoders for the 8 elements in each column or in each row of the precoding matrix, there may be 2 elements with non-zero values, and the other 6 elements are with value 0.
  • the value for the 2 elements with non-zero values may be at least one of ⁇ 1, -1, j, -j ⁇ or at least one of ⁇ 1, e j*2 ⁇ /8 , e j*2*2 ⁇ /8 , e j*3*2 ⁇ /8 , e j*4*2 ⁇ /8 , e j*5*2 ⁇ /8 , e j*6*2 ⁇ /8 , e j*7*2 ⁇ /8 ⁇ .
  • the value for the 1 element with non-zero values may be 1.
  • the set of precoding matrix may comprise one or more full coherent precoding matrixes.
  • the set of precoding matrix may comprise one or more partial-coherent precoding matrixes.
  • the set of precoding matrix may comprise one or more non-coherent precoding matrixes.
  • the set of precoding matrix may comprise one or more mixed partial and non-coherent precoding matrixes.
  • the set of precoding matrix may comprise one or more partial-coherent precoding matrixes.
  • the set of precoding matrix may comprise one or more mixed partial and non-coherent precoding matrixes.
  • the set of precoding matrix may comprise one or more non-coherent precoding matrixes.
  • the set of precoding matrix may comprise one or more non-coherent precoding matrixes.
  • N 1 there may be a parameter “N 1 ” , and “N 1 ” may represent a number of ports in a first dimension.
  • “N 1 ” may be at least one of ⁇ 1, 2, 4, 8 ⁇ .
  • “N 1 ” may be 2 or 4.
  • there may be a parameter “N2” and “N2” may represent a number of ports in a second dimension.
  • “N 2 ” may be at least one of ⁇ 1, 2, 4, 8 ⁇ .
  • N 2 may be 1 or 2.
  • a product of N1 and N2 may be 8.
  • the antenna structure may be linear array with one dimension.
  • the antenna structure may be single-polarized configuration.
  • a product of N1 and N2 may be 4.
  • the antenna structure may be linear array with two dimensions.
  • the antenna structure may be dual-polarized or cross-polarized configuration.
  • there may be a parameter “O 1 ” and “O 1 ” may represent a first discrete fourier transform (DFT) oversampling in the first dimension.
  • DFT discrete fourier transform
  • “O 1 ” may be at least one of ⁇ 1, 2, 4 ⁇ .
  • “O 1 ” may be 2 or 4.
  • there may be a parameter “O 2 ” and “O 2 ” may represent a second DFT oversampling in the second dimension.
  • “O 2 ” may be at least one of ⁇ 1, 2, 4 ⁇ .
  • “O 2 ” may be 2 or 4.
  • the first dimension may be horizontal dimension and the second dimension may be vertical dimension.
  • the first dimension may be vertical dimension and the second dimension may be horizontal dimension.
  • the first dimension may be horizontal dimension and the second dimension may be vertical dimension with a tilt.
  • the first dimension may be vertical dimension with a tilt and the second dimension may be horizontal dimension.
  • u m there may be a first vector u m .
  • u m may be a DFT vector.
  • m may be a non-negative integer. For example, 0 ⁇ m ⁇ O 2 N 2 .
  • m may be at least one of ⁇ 0, 2, 4, 6 ⁇ .
  • m may be at least one of ⁇ 0, 1, 2, 3 ⁇ .
  • m may be 0 or 1.
  • m may be 0 or 2.
  • m may be 0.
  • v l, m there may be a second vector v l, m .
  • l may be a non-negative integer. For example, 0 ⁇ l ⁇ O 1 N 1 .
  • l may be at least one of ⁇ 0, 2, 4, 6 ⁇ .
  • l may be at least one of ⁇ 0, 2, 4, 6, 8, 10, 12, 14 ⁇ .
  • l may be at least one of ⁇ 0, 1, 2, 3 ⁇ .
  • l may be 0 or 1.
  • l may be 0 or 2.
  • l may be 0.
  • [] T may represent a transposition of a vector or a matrix.
  • n may be a non-negative integer.
  • n may be at least one of ⁇ 0, 1, 2, 3 ⁇ .
  • n may be 0 or 1.
  • n may be 0 or 2.
  • n may be 0.
  • the terminal device 110 if the terminal device 110 is indicated with the number of layers as 8, there may be a first set of precoding matrixes corresponding to 8 layers (e.g. a first set of full coherent precoding matrixes) .
  • the first set of vectors corresponding to 1 layer may be applied for 8 Tx full coherent precoders with 1 layer and/or 8 Tx partial coherent precoders with 1 layer.
  • the 8 Tx partial coherent precoders may be a first partial coherent precoders.
  • the 8 Tx antennas may be comprised with two groups, and each group may comprise 4 antennas.
  • the 4 antennas in one group may be coherent.
  • the first set of vectors corresponding to 1 layer may be at least one of: and In some embodiments, the first set of vectors corresponding to 1 layer may be at least one of: and In some embodiments, the first set of vectors corresponding to 1 layer may be at least one of: and In some embodiments, the number of vectors in the first set of vectors corresponding to 1 layer 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 1 layer may be represented as In some embodiments, s may be a non-negative integer, and 0 ⁇ s ⁇ St 1, 1 -1 .
  • the value of p 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*2 ⁇ /8 , e j*2*2 ⁇ /8 , e j*3*2 ⁇ /8 , e j*4*2 ⁇ /8 , e j*5*2 ⁇ /8 , e j*6*2 ⁇ /8 , e j*7*2 ⁇ /8 ⁇ .
  • the at least one full coherent 8 Tx precoders and/or the at least one second full coherent 8 Tx precoders may comprise at least one of:
  • v 4, 1, 1 (s1) may be one vector from the first set of vectors corresponding to 1 layer.
  • v 4, 1, 1 (s2) may be one vector from the first set of vectors corresponding to 1 layer.
  • v 4, 1, 1 (s1) may be same or different from v 4, 1, 1 (s2) .
  • G may be at least one of ⁇ 4, 8, 12, 16 ⁇
  • g may be an integer from 0 to G-1.
  • the first antenna group with 4 antennas may comprise antennas with ⁇ AP0, AP2, AP4, AP6 ⁇ and the second antenna group with 4 antennas may comprise antennas with ⁇ AP1, AP3, AP5, AP7 ⁇ .
  • the at least one full coherent 8 Tx precoders and/or the at least one second full coherent 8 Tx precoders may comprise at least one of:
  • the first antenna group with 4 antennas may comprise antennas with ⁇ AP0, AP1, AP4, AP5 ⁇ and the second antenna group with 4 antennas may comprise antennas with ⁇ AP2, AP3, AP6, AP7 ⁇ .
  • the at least one full coherent 8 Tx precoders and/or the at least one second full coherent 8 Tx precoders may comprise at least one of:
  • the first antenna group with 4 antennas may comprise antennas with ⁇ AP0, AP1, AP2, AP3 ⁇ and the second antenna group with 4 antennas may comprise antennas with ⁇ AP4, AP5, AP6, AP7 ⁇ .
  • the at least one full coherent 8 Tx precoders and/or the at least one second full coherent 8 Tx precoders may comprise at least one of:
  • the at least one partial coherent 8 Tx precoders and/or the at least one first partial coherent 8 Tx precoders may comprise at least one of: and
  • v 4, 1, 1 (s1) may be one vector from the first set of vectors corresponding to 1 layer.
  • “0” in the and/or may represent a vector with 4 elements. For example, a vector of [0, 0, 0, 0] T .
  • the at least one partial coherent 8 Tx precoders and/or the at least one first partial coherent 8 Tx precoders may comprise at least one of: In some embodiments, for a second group of antennas or the second group of antennas is configured or indicated, the at least one partial coherent 8 Tx precoders and/or the at least one first partial coherent 8 Tx precoders may comprise at least one of:
  • the first antenna group with 4 antennas may comprise antennas with ⁇ AP0, AP2, AP4, AP6 ⁇ and the second antenna group with 4 antennas may comprise antennas with ⁇ AP1, AP3, AP5, AP7 ⁇ .
  • the at least one partial coherent 8 Tx precoders and/or the at least one first partial coherent 8 Tx precoders may comprise at least one of: and
  • the at least one partial coherent 8 Tx precoders and/or the at least one first partial coherent 8 Tx precoders may comprise at least one of:
  • the at least one partial coherent 8 Tx precoders and/or the at least one first partial coherent 8 Tx precoders may comprise at least one of:
  • the at least one partial coherent 8 Tx precoders and/or the at least one first partial coherent 8 Tx precoders may comprise at least one of:
  • the first antenna group with 4 antennas may comprise antennas with ⁇ AP0, AP1, AP4, AP5 ⁇ and the second antenna group with 4 antennas may comprise antennas with ⁇ AP2, AP3, AP6, AP7 ⁇ .
  • the at least one partial coherent 8 Tx precoders and/or the at least one first partial coherent 8 Tx precoders may comprise at least one of: and
  • the at least one partial coherent 8 Tx precoders and/or the at least one first partial coherent 8 Tx precoders may comprise at least one of:
  • the at least one partial coherent 8 Tx precoders and/or the at least one first partial coherent 8 Tx precoders may comprise at least one of:
  • the at least one partial coherent 8 Tx precoders and/or the at least one first partial coherent 8 Tx precoders may comprise at least one of:
  • the first antenna group with 4 antennas may comprise antennas with ⁇ AP0, AP1, AP2, AP3 ⁇ and the second antenna group with 4 antennas may comprise antennas with ⁇ AP4, AP5, AP6, AP7 ⁇ .
  • the at least one partial coherent 8 Tx precoders and/or the at least one first partial coherent 8 Tx precoders may comprise at least one of: and
  • the at least one partial coherent 8 Tx precoders and/or the at least one first partial coherent 8 Tx precoders may comprise at least one of:
  • the at least one partial coherent 8 Tx precoders and/or the at least one first partial coherent 8 Tx precoders may comprise at least one of:
  • the at least one partial coherent 8 Tx precoders and/or the at least one first partial coherent 8 Tx precoders may comprise at least one of:
  • s1 may be a non-negative integer, and 0 ⁇ s1 ⁇ St 1, 1 -1.
  • s2 may be a non-negative integer, and 0 ⁇ s2 ⁇ St 1, 1 -1.
  • the 8 Tx partial coherent precoders may be a first partial coherent precoders and/or a second partial coherent precoders.
  • the 8 Tx antennas may be comprised with two groups, and each group may comprise 4 antennas.
  • the 4 antennas in one group may be coherent.
  • the 8 Tx antennas may be comprised with four groups, and each group may comprise 2 antennas.
  • the 2 antennas in one group may be coherent.
  • the second set of vectors corresponding to 1 layer may be at least one of: and
  • 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.
  • St 1, 2 may be 4 or 8 or 16.
  • 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.
  • two value of the value of p 4, 1, 2 (s 4, 1, 2 , 0) and/or the value of p 4, 1, 2 (s 4, 1, 2 , 1) and/or the value of p 4, 1, 2 (s 4, 1, 2 , 2) and/or the value of p 4, 1, 2 (s 4, 1, 2 , 3) may be at least one of ⁇ 1, -1, j, -j ⁇ or at least one of ⁇ 1, e j*2 ⁇ /8 , e j*2*2 ⁇ /8 , e j*3*2 ⁇ /8 , e j*4*2 ⁇ /8 , e j*5*2 ⁇ /8 , e j*6*2 ⁇ /8 , e j*7*2 ⁇ /8 ⁇ .
  • the other two value of the value of p 4, 1, 2 (s 4, 1, 2 , 0) and/or the value of p 4, 1, 2 (s 4, 1, 2 , 1) and/or the value of p 4, 1, 2 (s 4, 1, 2 , 2) and/or the value of p 4, 1, 2 (s 4, 1, 2 , 3) may be 0.
  • the at least one partial coherent 8 Tx precoders and/or the at least one first partial coherent 8 Tx precoders may comprise at least one of:
  • v 4, 1, 2 (s 4, 1, 2, 1 ) may be one vector from the second set of vectors corresponding to 1 layer.
  • v 4, 1, 2 (s 4, 1, 2, 2 ) may be one vector from the second set of vectors corresponding to 1 layer.
  • v 4, 1, 2 (s 4, 1, 2, 1 ) may be same or different from v 4, 1, 2 (s 4, 1, 2, 2 ) .
  • G may be at least one of ⁇ 4, 8, 12, 16 ⁇
  • g may be an integer from 0 to G-1.
  • the first antenna group with 4 antennas may comprise antennas with ⁇ AP0, AP2, AP4, AP6 ⁇ and the second antenna group with 4 antennas may comprise antennas with ⁇ AP1, AP3, AP5, AP7 ⁇ .
  • the at least one partial coherent 8 Tx precoders and/or the at least one first partial coherent 8 Tx precoders may comprise at least one of:
  • the first antenna group with 4 antennas may comprise antennas with ⁇ AP0, AP1, AP4, AP5 ⁇ and the second antenna group with 4 antennas may comprise antennas with ⁇ AP2, AP3, AP6, AP7 ⁇ .
  • the at least one partial coherent 8 Tx precoders and/or the at least one first partial coherent 8 Tx precoders may comprise at least one of:
  • the first antenna group with 4 antennas may comprise antennas with ⁇ AP0, AP1, AP2, AP3 ⁇ and the second antenna group with 4 antennas may comprise antennas with ⁇ AP4, AP5, AP6, AP7 ⁇ .
  • the at least one partial coherent 8 Tx precoders and/or the at least one first partial coherent 8 Tx precoders may comprise at least one of:
  • the at least one partial coherent 8 Tx precoders and/or the at least one second partial coherent 8 Tx precoders may comprise at least one of: and
  • v 4, 1, 2 (s 4, 1, 2, 1 ) may be one vector from the second set of vectors corresponding to 1 layer.
  • “0” in the and may represent a vector with 4 elements. For example, a vector of [0, 0, 0, 0] T .
  • the at least one partial coherent 8 Tx precoders and/or the at least one second partial coherent 8 Tx precoders may comprise at least one of: In some embodiments, for a second group of antennas or the second group of antennas is configured or indicated, the at least one partial coherent 8 Tx precoders and/or the at least one second partial coherent 8 Tx precoders may comprise at least one of:
  • the first antenna group with 4 antennas may comprise antennas with ⁇ AP0, AP2, AP4, AP6 ⁇ and the second antenna group with 4 antennas may comprise antennas with ⁇ AP1, AP3, AP5, AP7 ⁇ .
  • the at least one partial coherent 8 Tx precoders and/or the at least one second partial coherent 8 Tx precoders may comprise at least one of: and
  • the at least one partial coherent 8 Tx precoders and/or the at least one second partial coherent 8 Tx precoders may comprise at least one of:
  • the at least one partial coherent 8 Tx precoders and/or the at least one second partial coherent 8 Tx precoders may comprise at least one of:
  • the first antenna group with 4 antennas may comprise antennas with ⁇ AP0, AP1, AP4, AP5 ⁇ and the second antenna group with 4 antennas may comprise antennas with ⁇ AP2, AP3, AP6, AP7 ⁇ .
  • the at least one partial coherent 8 Tx precoders and/or the at least one second partial coherent 8 Tx precoders may comprise at least one of: and
  • the at least one partial coherent 8 Tx precoders and/or the at least one second partial coherent 8 Tx precoders may comprise at least one of:
  • the at least one partial coherent 8 Tx precoders and/or the at least one second partial coherent 8 Tx precoders may comprise at least one of:
  • the first antenna group with 4 antennas may comprise antennas with ⁇ AP0, AP1, AP2, AP3 ⁇ and the second antenna group with 4 antennas may comprise antennas with ⁇ AP4, AP5, AP6, AP7 ⁇ .
  • the at least one partial coherent 8 Tx precoders and/or the at least one second partial coherent 8 Tx precoders may comprise at least one of: and
  • the at least one partial coherent 8 Tx precoders and/or the at least one second partial coherent 8 Tx precoders may comprise at least one of:
  • the at least one partial coherent 8 Tx precoders and/or the at least one second partial coherent 8 Tx precoders may comprise at least one of:
  • s 4, 1, 2, 1 may be a non-negative integer, and 0 ⁇ s 4, 1, 2, 1 ⁇ St 1, 2 -1.
  • s 4, 1, 2, 2 may be a non-negative integer, and 0 ⁇ s 4, 1, 2, 2 ⁇ St 1, 2 -1.
  • the third set of vectors corresponding to 1 layer may be applied for 8 Tx partial coherent precoders with 1 layer and/or 8 Tx non coherent precoders with 1 layer.
  • the 8 Tx partial coherent precoders may be a second partial coherent precoders.
  • the 8 Tx antennas may be comprised with four groups, and each group may comprise 2 antennas.
  • the 2 antennas in one group may be coherent.
  • the third set of vectors corresponding to 1 layer may be at least one of: and
  • the number of vectors in the third set of vectors corresponding to 1 layer may be St 1, 3 , and St 1, 3 may be a positive integer.
  • St 1, 3 may be 2 or4 or.
  • one vector in the third set of vectors corresponding to 1 layer may be represented as
  • s 4, 1, 3 may be a non-negative integer, and 0 ⁇ s 4, 1, 3 ⁇ St 1, 3 -1.
  • one value of 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 p 4, 1, 3 (s 4, 1, 3 , 2) and/or the value of p 4, 1, 3 (s 4, 1, 3 , 3) may be 1.
  • the other three values of 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 p 4, 1, 3 (s 4, 1, 3 , 2) and/or the value of p 4, 1, 3 (s 4, 1, 3 , 3) may be 0.
  • the at least one partial coherent 8 Tx precoders and/or the at least one second partial coherent 8 Tx precoders may comprise at least one of:
  • v 4, 1, 3 (s 4, 1, 3, 1 ) may be one vector from the third set of vectors corresponding to 1 layer.
  • v 4, 1, 3 (s 4, 1, 3, 2 ) may be one vector from the third set of vectors corresponding to 1 layer.
  • v 4, 1, 3 (s 4, 1, 3, 1 ) may be same or different from v 4, 1, 3 (s 4, 1, 3, 2 ) .
  • G may be at least one of ⁇ 4, 8, 12, 16 ⁇
  • g may be an integer from 0 to G-1.
  • the first antenna group with 4 antennas may comprise antennas with ⁇ AP0, AP2, AP4, AP6 ⁇ and the second antenna group with 4 antennas may comprise antennas with ⁇ AP1, AP3, AP5, AP7 ⁇ .
  • the at least one partial coherent 8 Tx precoders and/or the at least one second partial coherent 8 Tx precoders may comprise at least one of:
  • the first antenna group with 4 antennas may comprise antennas with ⁇ AP0, AP1, AP4, AP5 ⁇ and the second antenna group with 4 antennas may comprise antennas with ⁇ AP2, AP3, AP6, AP7 ⁇ .
  • the at least one partial coherent 8 Tx precoders and/or the at least one second partial coherent 8 Tx precoders may comprise at least one of:
  • the first antenna group with 4 antennas may comprise antennas with ⁇ AP0, AP1, AP2, AP3 ⁇ and the second antenna group with 4 antennas may comprise antennas with ⁇ AP4, AP5, AP6, AP7 ⁇ .
  • the at least one partial coherent 8 Tx precoders and/or the at least one second partial coherent 8 Tx precoders may comprise at least one of:
  • the at least one non coherent 8 Tx precoders may comprise at least one of: and In some embodiments, v 4, 1, 3 (s 4, 1, 3, 1 ) may be one vector from the third set of vectors corresponding to 1 layer. In some embodiments, “0” in the and may represent a vector with 4 elements. For example, a vector of [0, 0, 0, 0] T . In some embodiments, for a first group of antennas or the first group of antennas is configured or indicated, the at least one non coherent 8 Tx precoders may comprise at least one of: In some embodiments, for a second group of antennas or the second group of antennas is configured or indicated, the at least one non coherent 8 Tx precoders may comprise at least one of:
  • the first antenna group with 4 antennas may comprise antennas with ⁇ AP0, AP2, AP4, AP6 ⁇ and the second antenna group with 4 antennas may comprise antennas with ⁇ AP1, AP3, AP5, AP7 ⁇ .
  • the at least one non coherent 8 Tx precoders may comprise at least one of: and In some embodiments, for a first group of antennas or the first group of antennas is configured or indicated, the at least one non partial coherent 8 Tx precoders may comprise at least one of: In some embodiments, for a second group of antennas or the second group of antennas is configured or indicated, the at least one non coherent 8 Tx precoders may comprise at least one of:
  • the first antenna group with 4 antennas may comprise antennas with ⁇ AP0, AP1, AP4, AP5 ⁇ and the second antenna group with 4 antennas may comprise antennas with ⁇ AP2, AP3, AP6, AP7 ⁇ .
  • the at least one non coherent 8 Tx precoders may comprise at least one of: and In some embodiments, for a first group of antennas or the first group of antennas is configured or indicated, the at least one non coherent 8 Tx precoders may comprise at least one of: In some embodiments, for a second group of antennas or the second group of antennas is configured or indicated, the at least one non coherent 8 Tx precoders may comprise at least one of:
  • the first antenna group with 4 antennas may comprise antennas with ⁇ AP0, AP1, AP2, AP3 ⁇ and the second antenna group with 4 antennas may comprise antennas with ⁇ AP4, AP5, AP6, AP7 ⁇ .
  • the at least one non coherent 8 Tx precoders may comprise at least one of: and In some embodiments, for a first group of antennas or the first group of antennas is configured or indicated, the at least one non coherent 8 Tx precoders may comprise at least one of: In some embodiments, for a second group of antennas or the second group of antennas is configured or indicated, the at least one non coherent 8 Tx precoders may comprise at least one of:
  • s 4, 1, 3, 1 may be a non-negative integer, and 0 ⁇ s 4, 1, 3, 1 ⁇ St 1, 3 -1.
  • s 4, 1, 3, 2 may be a non-negative integer, and 0 ⁇ s 4, 1, 3, 2 ⁇ St 1, 3 -1.
  • the 8 Tx antennas may be comprised with two groups, and each group may comprise 4 antennas.
  • the 4 antennas in one group may be coherent.
  • the 8 Tx antennas may be comprised with four groups, and each group may comprise 2 antennas.
  • the 2 antennas in one group may be coherent.
  • the fourth set of vectors corresponding to 1 layer may be at least one of: and
  • the number of vectors in the fourth set of vectors corresponding to 1 layer may be St 1, 4 , and St 1, 4 may be a positive integer.
  • St 1, 4 may be 2 or 4.
  • one vector in the fourth set of vectors corresponding to 1 layer may be represented as
  • s 4, 1, 4 may be a non-negative integer, and 0 ⁇ s 4, 1, 4 ⁇ St 1, 4 -1 .
  • 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) may be at least one of ⁇ 1, -1, j, -j ⁇ or at least one of ⁇ 1, e j*2 ⁇ /8 , e j*2*2 ⁇ /8 , e j*3*2 ⁇ /8 , e j*4*2 ⁇ /8 , e j*5*2 ⁇ /8 , e j*6*2 ⁇ /8 , e j*7*2 ⁇ /8 ⁇ .
  • the at least one full coherent 8 Tx precoders and/or the at least one second full coherent 8 Tx precoders may comprise at least one of: 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 ) may be one vector from the fourth set of vectors corresponding to 1 layer.
  • 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 ) may be same or different from each other.
  • the first antenna group with 2 antennas may comprise antennas with ⁇ AP0, AP4 ⁇ and the second antenna group with 2 antennas may comprise antennas with ⁇ AP1, AP5 ⁇ and the third antenna group with 2 antennas may comprise antennas with ⁇ AP2, AP6 ⁇ and the fourth antenna group with 2 antennas may comprise antennas with ⁇ AP3, AP7 ⁇ .
  • the at least one full coherent 8 Tx precoders and/or the at least one second full coherent 8 Tx precoders may comprise at least one of:
  • the first antenna group with 2 antennas may comprise antennas with ⁇ AP0, AP1 ⁇ and the second antenna group with 2 antennas may comprise antennas with ⁇ AP2, AP3 ⁇ and the third antenna group with 2 antennas may comprise antennas with ⁇ AP4, AP5 ⁇ and the fourth antenna group with 2 antennas may comprise antennas with ⁇ AP6, AP7 ⁇ .
  • the at least one full coherent 8 Tx precoders and/or the at least one second full coherent 8 Tx precoders may comprise at least one of:
  • the first antenna group with 2 antennas may comprise antennas with ⁇ AP0, AP2 ⁇ and the second antenna group with 2 antennas may comprise antennas with ⁇ AP4, AP6 ⁇ and the third antenna group with 2 antennas may comprise antennas with ⁇ AP1, AP5 ⁇ and the fourth antenna group with 2 antennas may comprise antennas with ⁇ AP3, AP7 ⁇ .
  • the at least one full coherent 8 Tx precoders and/or the at least one second full coherent 8 Tx precoders may comprise at least one of:
  • the at least one partial coherent 8 Tx precoders and/or the at least one second partial coherent 8 Tx precoders may comprise at least one of: and
  • v 4, 1, 4 (s 4, 1, 4, 1 ) may be one vector from the fourth set of vectors corresponding to 1 layer.
  • “0” in the and may represent a vector with 6 elements. For example, a vector of [0, 0, 0, 0, 0] T .
  • the at least one partial coherent 8 Tx precoders and/or the at least one second partial coherent 8 Tx precoders may comprise at least one of: In some embodiments, for a fourth group of antennas with 2 antennas or the fourth group of antennas with 2 antennas is configured or indicated, the at least one partial coherent 8 Tx precoders and/or the at least one second partial coherent 8 Tx precoders may comprise at least one of:
  • the first antenna group with 2 antennas may comprise antennas with ⁇ AP0, AP4 ⁇ and the second antenna group with 2 antennas may comprise antennas with ⁇ AP1, AP5 ⁇ and the third antenna group with 2 antennas may comprise antennas with ⁇ AP2, AP6 ⁇ and the fourth antenna group with 2 antennas may comprise antennas with ⁇ AP3, AP7 ⁇ .
  • the at least one partial coherent 8 Tx precoders and/or the at least one second partial coherent 8 Tx precoders may comprise at least one of: and In some embodiments, for a first group of antennas with 2 antennas or the first group of antennas with 2 antennas is configured or indicated, the at least one partial coherent 8 Tx precoders and/or the at least one second partial coherent 8 Tx precoders may comprise at least one of: In some embodiments, for a second group of antennas with 2 antennas or the second group of antennas with 2 antennas is configured or indicated, the at least one partial coherent 8 Tx precoders and/or the at least one second partial coherent 8 Tx precoders may comprise at least one of: In some embodiments, for a third group of antennas with 2 antennas or the third group of antennas with 2 antennas is configured or indicated, the at least one partial coherent 8 Tx precoders and/or the at least one second partial coherent 8 Tx precoders may comprise at least one of: In some embodiments, for
  • the first antenna group with 2 antennas may comprise antennas with ⁇ AP0, AP1 ⁇ and the second antenna group with 2 antennas may comprise antennas with ⁇ AP2, AP3 ⁇ and the third antenna group with 2 antennas may comprise antennas with ⁇ AP4, AP5 ⁇ and the fourth antenna group with 2 antennas may comprise antennas with ⁇ AP6, AP7 ⁇ .
  • the at least one partial coherent 8 Tx precoders and/or the at least one second partial coherent 8 Tx precoders may comprise at least one of: and In some embodiments, for a first group of antennas with 2 antennas or the first group of antennas with 2 antennas is configured or indicated, the at least one partial coherent 8 Tx precoders and/or the at least one second partial coherent 8 Tx precoders may comprise at least one of: In some embodiments, for a second group of antennas with 2 antennas or the second group of antennas with 2 antennas is configured or indicated, the at least one partial coherent 8 Tx precoders and/or the at least one second partial coherent 8 Tx precoders may comprise at least one of: In some embodiments, for a third group of antennas with 2 antennas or the third group of antennas with 2 antennas is configured or indicated, the at least one partial coherent 8 Tx precoders and/or the at least one second partial coherent 8 Tx precoders may comprise at least one of: In some embodiments, for
  • the first antenna group with 2 antennas may comprise antennas with ⁇ AP0, AP2 ⁇ and the second antenna group with 2 antennas may comprise antennas with ⁇ AP4, AP6 ⁇ and the third antenna group with 2 antennas may comprise antennas with ⁇ AP1, AP5 ⁇ and the fourth antenna group with 2 antennas may comprise antennas with ⁇ AP3, AP7 ⁇ .
  • the at least one partial coherent 8 Tx precoders and/or the at least one second partial coherent 8 Tx precoders may comprise at least one of: and In some embodiments, for a first group of antennas with 2 antennas or the first group of antennas with 2 antennas is configured or indicated, the at least one partial coherent 8 Tx precoders and/or the at least one second partial coherent 8 Tx precoders may comprise at least one of: In some embodiments, for a second group of antennas with 2 antennas or the second group of antennas with 2 antennas is configured or indicated, the at least one partial coherent 8 Tx precoders and/or the at least one second partial coherent 8 Tx precoders may comprise at least one of: In some embodiments, for a third group of antennas with 2 antennas or the third group of antennas with 2 antennas is configured or indicated, the at least one partial coherent 8 Tx precoders and/or the at least one second partial coherent 8 Tx precoders may comprise at least one of: In some embodiments, for
  • s 4, 1, 4, 1 may be a non-negative integer, and 0 ⁇ s 4, 1, 4, 1 ⁇ St 1, 4 -1.
  • s 4, 1, 4, 2 may be a non-negative integer, and 0 ⁇ s 4, 1, 4, 2 ⁇ St 1, 4 -1.
  • s 4, 1, 4, 3 may be a non-negative integer, and 0 ⁇ s 4, 1, 4, 3 ⁇ St 1, 4 -1.
  • s 4, 1, 4, 4 may be a non-negative integer, and 0 ⁇ s 4, 1, 4, 4 ⁇ St 1, 4 -1.
  • the 8 Tx antennas may be comprised with two groups, and each group may comprise 4 antennas.
  • the 4 antennas in one group may be coherent.
  • the 8 Tx antennas may be comprised with four groups, and each group may comprise 2 antennas.
  • the 2 antennas in one group may be coherent.
  • the fifth set of vectors corresponding to 1 layer may be at least one of:
  • the number of vectors in the fifth set of vectors corresponding to 1 layer may be St 1, 5
  • St 1, 5 may be a positive integer.
  • St 1, 5 may be 2.
  • one vector in the fifth set of vectors corresponding to 1 layer may be represented as
  • s 4, 1, 5 may be a non-negative integer, and 0 ⁇ s 4, 1, 5 ⁇ St 1, 5 -1 .
  • 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) may be either 0 or 1.
  • the at least one partial coherent 8 Tx precoders and/or the at least one first partial coherent 8 Tx precoders may comprise at least one of: 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 one vector from the fifth set of vectors corresponding to 1 layer.
  • 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 same or different from each other.
  • the first antenna group with 2 antennas may comprise antennas with ⁇ AP0, AP4 ⁇ and the second antenna group with 2 antennas may comprise antennas with ⁇ AP1, AP5 ⁇ and the third antenna group with 2 antennas may comprise antennas with ⁇ AP2, AP6 ⁇ and the fourth antenna group with 2 antennas may comprise antennas with ⁇ AP3, AP7 ⁇ .
  • the at least one partial coherent 8 Tx precoders and/or the at least one first partial coherent 8 Tx precoders may comprise at least one of:
  • the first antenna group with 2 antennas may comprise antennas with ⁇ AP0, AP1 ⁇ and the second antenna group with 2 antennas may comprise antennas with ⁇ AP2, AP3 ⁇ and the third antenna group with 2 antennas may comprise antennas with ⁇ AP4, AP5 ⁇ and the fourth antenna group with 2 antennas may comprise antennas with ⁇ AP6, AP7 ⁇ .
  • the at least one partial coherent 8 Tx precoders and/or the at least one first partial coherent 8 Tx precoders may comprise at least one of:
  • the first antenna group with 2 antennas may comprise antennas with ⁇ AP0, AP2 ⁇ and the second antenna group with 2 antennas may comprise antennas with ⁇ AP4, AP6 ⁇ and the third antenna group with 2 antennas may comprise antennas with ⁇ AP1, AP5 ⁇ and the fourth antenna group with 2 antennas may comprise antennas with ⁇ AP3, AP7 ⁇ .
  • the at least one partial coherent 8 Tx precoders and/or the at least one first partial coherent 8 Tx precoders may comprise at least one of:
  • the at least one non coherent 8 Tx precoders may comprise at least one of: and
  • v 4, 1, 5 may be one vector from the fourth set of vectors corresponding to 1 layer.
  • “0” in the and may represent a vector with 6 elements. For example, a vector of [0, 0, 0, 0, 0] T .
  • the at least one non coherent 8 Tx precoders may comprise at least one of: In some embodiments, for a fourth group of antennas with 2 antennas or the fourth group of antennas with 2 antennas is configured or indicated, the at least one non coherent 8 Tx precoders may comprise at least one of:
  • the first antenna group with 2 antennas may comprise antennas with ⁇ AP0, AP4 ⁇ and the second antenna group with 2 antennas may comprise antennas with ⁇ AP1, AP5 ⁇ and the third antenna group with 2 antennas may comprise antennas with ⁇ AP2, AP6 ⁇ and the fourth antenna group with 2 antennas may comprise antennas with ⁇ AP3, AP7 ⁇ .
  • the at least one non coherent 8 Tx precoders may comprise at least one of: and In some embodiments, for a first group of antennas with 2 antennas or the first group of antennas with 2 antennas is configured or indicated, the at least one non coherent 8 Tx precoders may comprise at least one of: In some embodiments, for a second group of antennas with 2 antennas or the second group of antennas with 2 antennas is configured or indicated, the at least one non coherent 8 Tx precoders may comprise at least one of: In some embodiments, for a third group of antennas with 2 antennas or the third group of antennas with 2 antennas is configured or indicated, the at least one non coherent 8 Tx precoders may comprise at least one of: In some embodiments, for a fourth group of antennas with 2 antennas or the third group of antennas with 2 antennas is configured or indicated, the at least one non coherent 8 Tx precoders may comprise at least one of:
  • the first antenna group with 2 antennas may comprise antennas with ⁇ AP0, AP1 ⁇ and the second antenna group with 2 antennas may comprise antennas with ⁇ AP2, AP3 ⁇ and the third antenna group with 2 antennas may comprise antennas with ⁇ AP4, AP5 ⁇ and the fourth antenna group with 2 antennas may comprise antennas with ⁇ AP6, AP7 ⁇ .
  • the at least one non coherent 8 Tx precoders may comprise at least one of: and In some embodiments, for a first group of antennas with 2 antennas or the first group of antennas with 2 antennas is configured or indicated, the at least one non coherent 8 Tx precoders may comprise at least one of: In some embodiments, for a second group of antennas with 2 antennas or the second group of antennas with 2 antennas is configured or indicated, the at least one non coherent 8 Tx precoders may comprise at least one of: In some embodiments, for a third group of antennas with 2 antennas or the third group of antennas with 2 antennas is configured or indicated, the at least one non coherent 8 Tx precoders may comprise at least one of: In some embodiments, for a fourth group of antennas with 2 antennas or the fourth group of antennas with 2 antennas is configured or indicated, the at least one non coherent 8 Tx precoders may comprise at least one of:
  • the first antenna group with 2 antennas may comprise antennas with ⁇ AP0, AP2 ⁇ and the second antenna group with 2 antennas may comprise antennas with ⁇ AP4, AP6 ⁇ and the third antenna group with 2 antennas may comprise antennas with ⁇ AP1, AP5 ⁇ and the fourth antenna group with 2 antennas may comprise antennas with ⁇ AP3, AP7 ⁇ .
  • the at least one non coherent 8 Tx precoders may comprise at least one of: 0, 0, 0, p 4, 1, 5 (s 4, 1, 5, 1 , 1) , 0, 0 T and In some embodiments, for a first group of antennas with 2 antennas or the first group of antennas with 2 antennas is configured or indicated, the at least one non coherent 8 Tx precoders may comprise at least one of: In some embodiments, for a second group of antennas with 2 antennas or the second group of antennas with 2 antennas is configured or indicated, the at least one non coherent 8 Tx precoders may comprise at least one of: In some embodiments, for a third group of antennas with 2 antennas or the third group of antennas with 2 antennas is configured or indicated, the at least one partial coherent 8 Tx precoders and/or the at least one second partial coherent 8 Tx precoders may comprise at least one of: In some embodiments, for a fourth group of antennas with 2 antennas or the fourth group of antennas with 2 antennas is configured
  • s 4, 1, 5, 1 may be a non-negative integer, and 0 ⁇ s 4, 1, 5, 1 ⁇ St 1, 5 -1.
  • s 4, 1, 5, 2 may be a non-negative integer, and 0 ⁇ s 4, 1, 5, 2 ⁇ St 1, 5 -1.
  • s 4, 1, 5, 3 may be a non-negative integer, and 0 ⁇ s 4, 1, 5, 3 ⁇ St 1, 5 -1.
  • s 4, 1, 5, 4 may be a non-negative integer, and 0 ⁇ s 4, 1, 5, 4 ⁇ St 1, 5 -1.
  • the first set of vectors corresponding to 2 columns or rows may be at least one of: and
  • the second set of vectors corresponding to 2 columns or rows may be at least one of: and
  • the third set of vectors corresponding to 2 columns or rows may be at least one of: and
  • the third set of vectors corresponding to 2 columns or rows may be at least one of: and
  • the third set of vectors corresponding to 2 columns or rows may be at least one of:
  • At least one of 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 coherent precoders for 2 layers 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 the embodiments for at least one of the first set of vectors corresponding to 1 layer, the second set of vectors corresponding to 1 layer, the third set of vectors corresponding to1 layer, the fourth set of vectors corresponding to 1 layer and the fifth set of vectors corresponding to1 layer.
  • each of the 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 for 2 columns or 2 rows of the precoders for 2 layers or 5 layers.
  • first set of vectors corresponding to 3 columns or rows 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 for 8 Tx full coherent precoders with 3 layers or 6 layers or 5 layers or 7 layers and/or 8 Tx partial coherent precoders with 3 layers or 6 layers or 5 layers or 7 layers and/or 8 Tx first partial coherent precoders with 3 layers or 6 layers or 5 layers or 7 layers.
  • the first set of vectors corresponding to 3 columns or rows may be at least one of:
  • the second set of vectors corresponding to 3 columns or rows may be at least one of: and
  • the third set of vectors corresponding to 3 columns or rows may be at least one of:
  • At least one of 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 coherent precoders 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 first set of vectors corresponding to 1 layer, the second set of vectors corresponding to 1 layer, the third set of vectors corresponding to1 layer, the fourth set of vectors corresponding to 1 layer and the fifth set of vectors corresponding to1 layer.
  • each of the 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 for 3 columns or 3 rows of the precoders for 3 layers or 6 layers or 5 layers or 7 layers.
  • first set of vectors corresponding to 4 columns or rows 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 for 8 Tx full coherent precoders with 4 layers or 8 layers or 7 layers and/or 8 Tx partial coherent precoders with 4 layers or 8 layers or 7 layers and/or 8 Tx first partial coherent precoders with 4 layers or 8 layers or 7 layers.
  • the first set of vectors corresponding to 4 columns or rows may be at least one of:
  • the second set of vectors corresponding to 4 columns or rows may be at least one of: and
  • the third set of vectors corresponding to 4 columns or rows may be at least one of:
  • At least one of 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 coherent precoders 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 first set of vectors corresponding to 1 layer, the second set of vectors corresponding to 1 layer, the third set of vectors corresponding to1 layer, the fourth set of vectors corresponding to 1 layer and the fifth set of vectors corresponding to1 layer.
  • each of the 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 for 4 columns or 4 rows of the precoders for 4 layers or 7 layers or 8 layers.
  • 2 columns or rows of the precoder may comprise the first and/or second and/or third and/or fourth and/or fifth set of vectors corresponding to 2 columns or rows, and other 3 columns or rows of the precoder may comprise the first and/or the second and/or the third set of vectors corresponding to 3 columns or rows.
  • 1 columns or rows of the precoder may comprise the first and/or second and/or third and/or fourth and/or fifth set of vectors corresponding to 1 layer, and other 4 columns or rows of the precoder may comprise the first and/or the second and/or the third set of vectors corresponding to 4 columns or rows.
  • 2 columns or rows of the precoder may comprise the first and/or second and/or third and/or fourth and/or fifth set of vectors corresponding to 2 columns or rows, and other 4 columns or rows of the precoder may comprise the first and/or the second and/or the third set of vectors corresponding to 4 columns or rows.
  • 1 columns or rows of the precoder may comprise the first and/or second and/or third and/or fourth and/or fifth set of vectors corresponding to 1 layer, and other 4 columns or rows of the precoder may comprise the first and/or the second and/or the third set of vectors corresponding to 4 columns or rows.
  • 3 columns or rows of the precoder may comprise the first and/or second and/or third and/or fourth and/or fifth set of vectors corresponding to 3 columns or rows, and other 3 columns or rows of the precoder may comprise the first and/or the second and/or the third set of vectors corresponding to 3 columns or rows.
  • 3 columns or rows of the precoder may comprise the first and/or second and/or third and/or fourth and/or fifth set of vectors corresponding to 3 columns or rows, and other 4 columns or rows of the precoder may comprise the first and/or the second and/or the third set of vectors corresponding to 4 columns or rows.
  • 4 columns or rows of the precoder may comprise the first and/or second and/or third and/or fourth and/or fifth set of vectors corresponding to 4 columns or rows, and other 4 columns or rows of the precoder may comprise the first and/or the second and/or the third set of vectors corresponding to 4 columns or rows.
  • P may be 8 or 12 or 16.
  • l may be a non-negative integer. For example, 0 ⁇ l ⁇ O 1 N 1 . For another example, 0 ⁇ l ⁇ O 1 N 1 /2.
  • l may be at least one of ⁇ 0, 2, 4, 6 ⁇ .
  • l may be at least one of ⁇ 0, 1, 2, 3 ⁇ .
  • l may be 0 or 1.
  • l may be 0 or 2.
  • m may be a non-negative integer. For example, 0 ⁇ m ⁇ O 2 N 2 .
  • m may be at least one of ⁇ 0, 2, 4, 6 ⁇ .
  • n may be a non-negative integer.
  • n may be at least one of ⁇ 0, 1, 2, 3 ⁇ .
  • n may be 0 or 1.
  • n may be 0 or 2.
  • n may be 0.
  • l′ l+O 1 .
  • l′′ l+2O 1 .
  • l′′′ l+3O 1 .
  • the first set of precoding matrixes corresponding to 8 layers may comprise more than one subset. For example, there may be two subsets of precoding matrixes.
  • l may be a non-negative integer, 0 ⁇ l ⁇ O 1 N 1 .
  • l may be at least one of ⁇ 0, 2, 4, 6 ⁇ .
  • l may be at least one of ⁇ 0, 1, 2, 3 ⁇ .
  • l may be 0 or 1.
  • l may be 0 or 2.
  • the number of precoding matrixes in the first subset corresponding to 8 layers may be 32 or 16 or 8 or 4 or 2.
  • the value of “O 2 ” may be 4 or 2 or 1.
  • l may be a non-negative integer, 0 ⁇ l ⁇ O 1 N 1 .
  • l may be at least one of ⁇ 0, 2, 4, 6 ⁇ .
  • l may be at least one of ⁇ 0, 1, 2, 3 ⁇ .
  • l may be 0 or 1.
  • l may be 0 or 2.
  • m may be a non-negative integer.
  • 0 ⁇ m ⁇ O 2 N 2 .
  • m may be at least one of ⁇ 0, 2, 4, 6, 8 ⁇ .
  • m may be at least one of ⁇ 0, 1, 2, 3 ⁇ .
  • m may be 0 or 1.
  • m may be 0.
  • the number of precoding matrixes in the second subset corresponding to 8 layers may be 128 or 32 or 16 or 8 or 4 or 2.
  • the parameter “N 1 ” represents a number of ports in a first dimension.
  • the parameter “N2” represents a number of ports in a second dimension.
  • the parameter “O 1 ” represents a first discrete fourier transform (DFT) oversampling in the first dimension and the parameter “O 2 ” represents a second DFT oversampling in the second dimension.
  • the parameter “i” represents an element in the precoding matrix.
  • N 1 may equal to 4, N 2 equals to 1, O 1 may equal to 2 and O 2 may equal to 1 and i 1, 1 may be one of ⁇ 0, ...N 1 O 1 -1 ⁇ or ⁇ 0, 2, 4, 6 ⁇ or ⁇ 0, 4 ⁇ or ⁇ 0, 1 ⁇ or 0 or ⁇ 0, ...N 1 O 1 /2-1 ⁇ or ⁇ 0, 2 ⁇ .
  • the first subset of full coherent precoding matrixes corresponding to 8 layers “Set_f8_1” may comprise 16 precoding matrixes.
  • the subset of precoding matrixes “Set_f8_1” may comprise 8 precoding matrixes.
  • the subset of precoding matrixes “Set_f8_1” may comprise 4 precoding matrixes.
  • the subset of precoding matrixes “Set_f8_1” may comprise 2 precoding matrixes.
  • N 1 may equal to 2
  • N 2 equals to 2
  • O 1 may equal to 1 or4
  • O 2 may equal to 2 or 4
  • i 1, 1 or i 1, 2 may be one of ⁇ 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 full coherent precoding matrixes corresponding to 8 layers “Set_f8_2” may comprise 128 precoding matrixes.
  • the subset of precoding matrixes “Set_f8_2” may comprise 32 precoding matrixes.
  • the subset of precoding matrixes “Set_f8_2” may comprise 8 precoding matrixes.
  • the subset of precoding matrixes “Set_f8_2” may comprise 2 precoding matrixes.
  • the terminal device 110 if the terminal device 110 is indicated with the number of layers as 8, there may be a second set of precoding matrixes (e.g. a second set of partial coherent precoding matrixes) corresponding to 8 layers.
  • a second set of precoding matrixes e.g. a second set of partial coherent precoding matrixes
  • the terminal device 110 has 8 antenna ports or if a PUSCH transmission of the terminal device 110 is associated with 8 antenna ports or if a PUSCH transmission of the terminal device 110 is associated with SRS with 8 ports, 4 antenna ports (e.g. a first set of 4 ports) may be coherent and the other 4 antenna ports (e.g. a second set of 4 ports) may be coherent.
  • the first set of 4 ports may not be coherent with the second set of 4 ports.
  • a second set of precoding matrixes corresponding to 8 layers, for example, represented as “Set_p8_1”
  • the size of a partial coherent precoding matrix may be 8 multiplies 8.
  • 4 elements out of 8 elements in the partial coherent precoding matrix may be with non-zero value.
  • the other 4 elements in the partial coherent precoding matrix may be with value of 0.
  • the indexes of the 4 elements with non-zero values may be same in the first set of 4 columns or rows.
  • the indexes of the 4 elements with non-zero values may be idx_1, and idx_1 may be 4 values out of ⁇ 0, 1, 2, 3, 4, 5, 6, 7 ⁇ or ⁇ 1, 2, 3, 4, 5, 6, 7, 8 ⁇ .
  • idx_1 may be ⁇ 0, 1, 2, 3 ⁇ or ⁇ 0, 2, 4, 6 ⁇ or ⁇ 1, 2, 3, 4 ⁇ or ⁇ 1, 3, 5, 7 ⁇ .
  • the 4 values of idx_1 may be based on the indexes of antenna ports in the first group with 4 antenna ports.
  • non-zero values may be mapped on 4 out of 8 elements and 0 may be mapped on the other 4 elements.
  • the indexes of the 4 elements with non-zero values may be same in the second set of 4 columns or rows.
  • the indexes of the 4 elements with non-zero values may be idx_2, and idx_2 may be 4 values out of ⁇ 0, 1, 2, 3, 4, 5, 6, 7 ⁇ or ⁇ 1, 2, 3, 4, 5, 6, 7, 8 ⁇ .
  • idx_2 may be ⁇ 4, 5, 6, 7 ⁇ or ⁇ 1, 3, 5, 7 ⁇ or ⁇ 5, 6, 7, 8 ⁇ or ⁇ 2, 4, 6, 8 ⁇ .
  • the 4 values of idx_2 may be based on the indexes of antenna ports in the second group with 4 antenna ports.
  • any value of idx_1 may be different from any value of idx_2.
  • each set may include 4 length-4 vectors.
  • the values in a length-4 vector may be applied for the 4 non-zero values mapping on 4 elements in a column or row of the precoding matrix.
  • the first set of length-4 vectors may be ⁇ [1; 1; 1; 1] , [1; -1; 1; -1] , [1; 1; -1; -1] , [1; -1; -1; 1] ⁇ .
  • the second set of length-4 vectors may be ⁇ [1; 1; j; j] , [1; -1; j; -j] , [1; 1; -j; -j] , [1; -1; -j; j] ⁇ .
  • the 4 values in each vector of the first set or of the second set may be mapped on the 4 out of 8 elements, and 0 may be mapped on other 4 elements in a column or row of the precoding matrix.
  • the set of precoding matrixes “Set_p8_1” may comprise 280 precoding matrixes which is C (2, 1) *C (2, 1) *C (8, 4) .
  • C (x, y) may represent permutation and combination.
  • C (x, y) may represent number of possibilities of selecting y values out of x values.
  • each of [a1, a2, a3, a4] , [b1, b2, b3, b4] , [c1, c2, c3, c4] and [d1, d2, d3, d4] may be one of the length-4 vectors in the first set of length-4 vectors or in the second set of length-4 vectors.
  • each of [e1, e2, e3, e4] , [f1, f2, f3, f4] , [g1, g2, g3, g4] and [h1, h2, h3, h4] may be one of the length-4 vectors in the first set of length-4 vectors or in the second set of length-4 vectors.
  • [a1, a2, a3, a4] , [b1, b2, b3, b4] , [c1, c2, c3, c4] and [d1, d2, d3, d4] may be [1; 1; 1; 1] , [1; -1; 1; -1] , [1; 1; -1; -1] and [1; -1; -1; 1] , respectively.
  • [a1, a2, a3, a4] , [b1, b2, b3, b4] , [c1, c2, c3, c4] and [d1, d2, d3, d4] may be [1; 1; j; j] , [1; -1; j; -j] , [1; 1; -j; -j] and [1; -1; -j; j] , respectively.
  • [e1, e2, e3, e4] , [f1, f2, f3, f4] , [g1, g2, g3, g4] and [h1, h2, h3, h4] may be [1; 1; 1; 1] , [1; -1; 1; -1] , [1; 1; -1; -1] and [1; -1; -1; 1] , respectively.
  • [e1, e2, e3, e4] , [f1, f2, f3, f4] , [g1, g2, g3, g4] and [h1, h2, h3, h4] may be [1; 1; j; j] , [1; -1; j; -j] , [1; 1; -j; -j] and [1; -1; -j; j] , respectively.
  • s 8 may a positive integer. For example, 1 ⁇ s 8 ⁇ 64.
  • s 8 may be 64 or 32 or 16 or 8 or 4 or 2.
  • the terminal device 110 is indicated with the number of layers as 8, there may be a third set of precoding matrixes (e.g. a third set of partial coherent precoding matrixes) corresponding to 8 layers.
  • the structure of 8 ports may be 2+2+2+2, which means that there are 4 groups, each group including 2 antenna ports and in each group, the 2 antenna ports can be coherent. For example, between the groups, the antenna ports may not be coherent.
  • the indexes of the 2 elements with non-zero values may be same in the first set of 2 columns or rows.
  • the indexes of the 2 elements with non-zero values may be idx_1, and idx_1 may be 2 values out of ⁇ 0, 1, 2, 3, 4, 5, 6, 7 ⁇ or ⁇ 1, 2, 3, 4, 5, 6, 7, 8 ⁇ .
  • the 2 values of idx_1 may be based on the indexes of two out of the 4 antenna ports in the first group.
  • the 2 values of idx_1 may be based on the indexes of the 2 antenna ports in the third group.
  • idx_1 may be ⁇ 0, 1 ⁇ or ⁇ 0, 2 ⁇ or ⁇ 1, 2 ⁇ or ⁇ 1, 3 ⁇ or ⁇ 0, 4 ⁇ or ⁇ 1, 5 ⁇ .
  • the indexes of the 2 elements with non-zero values may be same in the second set of 2 columns or rows.
  • the indexes of the 2 elements with non-zero values may be idx_2, and idx_2 may be 2 values out of ⁇ 0, 1, 2, 3, 4, 5, 6, 7 ⁇ or ⁇ 1, 2, 3, 4, 5, 6, 7, 8 ⁇ .
  • the 2 values of idx_2 may be based on the indexes of the other two of the 4 antenna ports in the first group.
  • the 2 values of idx_2 may be based on the indexes of the 2 antenna ports in the fourth group.
  • idx_2 may be ⁇ 2, 3 ⁇ or ⁇ 1, 3 ⁇ or ⁇ 3, 4 ⁇ or ⁇ 2, 4 ⁇ or ⁇ 1, 5 ⁇ or ⁇ 2, 6 ⁇ .
  • the indexes of the 2 elements with non-zero values may be same in the third set of 2 columns or rows.
  • the indexes of the 2 elements with non-zero values may be idx_3, and idx_3 may be 2 values out of ⁇ 0, 1, 2, 3, 4, 5, 6, 7 ⁇ or ⁇ 1, 2, 3, 4, 5, 6, 7, 8 ⁇ .
  • the 2 values of idx_3 may be based on the indexes of two out of the 4 antenna ports in the second group. In some embodiments, the 2 values of idx_3 may be based on the indexes of the 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 the 8 columns or rows (e.g.
  • non-zero values may be mapped on 2 out of 8 elements and 0 may be mapped on the other 6 elements.
  • the indexes of the 2 elements with non-zero values may be same in the fourth set of 2 columns or rows.
  • the indexes of the 2 elements with non-zero values may be idx_4, and idx_4 may be 2 values out of ⁇ 0, 1, 2, 3, 4, 5, 6, 7 ⁇ or ⁇ 1, 2, 3, 4, 5, 6, 7, 8 ⁇ .
  • the 2 values of idx_4 may be based on the indexes of the other two of the 4 antenna ports in the first group.
  • the 2 values of idx_4 may be based on the indexes of the 2 antenna ports in the sixth group.
  • idx_4 may be ⁇ 6, 7 ⁇ or ⁇ 5, 7 ⁇ or ⁇ 7, 8 ⁇ or ⁇ 6, 8 ⁇ or ⁇ 3, 7 ⁇ or ⁇ 4, 8 ⁇ .
  • 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.
  • each one of the length-2 vector may be applied as the two non-zero values in a column or row of the precoding matrix.
  • two length-2 vectors can be selected from the 4 length-2 vectors, and the 2 values in each vector may be mapped on 2 out of 8 elements, and 0 may be mapped on other elements in a column or row of the precoding matrix.
  • there may be two sets of length-2 vectors and each set may include 2 length-2 vectors.
  • the two values in a length-2 vector may be applied as the two non-zero values mapping on 2 elements in a column or row of the precoding matrix.
  • the first set of the length-2 vectors may be ⁇ [1; 1] , [1; -1] ⁇ .
  • the second set of the length-2 vectors may be ⁇ [1; j] , [1; -j] ⁇ .
  • the 2 values in each vector of the first set or of the second set may be mapped on 2 out of 8 elements, and 0 may be mapped on other 6 elements in a column or row of the precoding matrix.
  • each of [a1, a2] , [b1, b2] may be one of the length-2 vectors in the first set of length-2 vectors or in the second set of length-2 vectors.
  • each of [c1, c2] and [d1, d2] may be one of the length-2 vectors in the first set of length-2 vectors or in the second set of length-2 vectors.
  • each of [e1, e2] , [f1, f2] may be one of the length-2 vectors in the first set of length-2 vectors or in the second set of length-2 vectors.
  • each of [g1, g2] and [h1, h2] may be one of the length-2 vectors in the first set of length-2 vectors or in the second set of length-2 vectors.
  • [a1, a2] , [b1, b2] may be [1; 1] , [1; -1] , respectively.
  • [a1, a2] , [b1, b2] may be [1; j] , [1; -j] , respectively.
  • [c1, c2] and [d1, d2] may be [1; 1] , [1; -1] , respectively.
  • [c1, c2] and [d1, d2] may be [1; j] , [1; -j] , respectively.
  • [e1, e2] , [f1, f2] may be [1; 1] , [1; -1] , respectively.
  • [e1, e2] , [f1, f2] may be [1; j] , [1; -j] , respectively.
  • [g1, g2] and [h1, h2] may be [1; 1] , [1; -1] , respectively.
  • [g1, g2] and [h1, h2] may be [1; j] , [1; -j] , respectively.
  • the terminal device 110 if the terminal device 110 is indicated with the number of layers as 8, there may be a fourth set of precoding matrixes (e.g. a fourth set of non-coherent precoding matrixes) corresponding to 8 layers. For example, each one of 8 antenna ports may be non-coherent with each other.
  • there may be a fourth set of precoding matrixes corresponding to 8 layers e.g. a fourth set of non-coherent precoding matrixes
  • the size of a precoding matrix may be 8 multiplies 8.
  • 1 element out of 8 elements in the precoding matrix may be with non-zero value.
  • the non-zero value may be 1.
  • the other 7 elements in the precoding matrix may be with value of 0.
  • the non-zero value may be mapped on 1 out of 8 elements and 0 may be mapped on the other 7 elements.
  • the indexes of the element with non-zero value may be different in each row or column of the precoding matrix.
  • the index of the 1 element with 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 column or row of the precoding matrix, respectively, and for each one of idx_1, idx_2, idx_3, idx_4, idx_5, idx_6, idx_7, idx_8, 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 ⁇ .
  • the value 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.
  • the value 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.
  • the value of idx_1, idx_2, idx_3, idx_4, idx_5, idx_6, idx_7, idx_8 may be different from each other.
  • the terminal device 110 is indicated with number of layers is indicated as 8, there may be a fourth set of precoding matrixes corresponding to 8 layers. For example, there may be only one precoding matrix in the fourth set (e.g. non-coherent precoding matrix) corresponding to 8 layers.
  • the terminal device 110 if the terminal device 110 is indicated with the number of layers as 8, there may be a fifth set of precoding matrixes (for example, mixed partial coherent precoding matrixes) corresponding to 8 layers.
  • the structure of the 8 ports may 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.
  • there may be a fifth set of precoding matrixes corresponding to 8 layers e.g. mixed partial coherent precoding matrix
  • the size of a partial coherent precoding matrix may be 8 multiplies 8.
  • the indexes of the 4 elements with non-zero values may be same in the first set of 4 columns or rows.
  • the indexes of the 4 elements with non-zero values may be idx_1, and idx_1 may be 4 values out of ⁇ 0, 1, 2, 3, 4, 5, 6, 7 ⁇ or ⁇ 1, 2, 3, 4, 5, 6, 7, 8 ⁇ .
  • idx_1 may be ⁇ 0, 1, 2, 3 ⁇ or ⁇ 0, 2, 4, 6 ⁇ or ⁇ 1, 2, 3, 4 ⁇ or ⁇ 1, 3, 5, 7 ⁇ .
  • the indexes of the 2 elements with non-zero values may be same in the second set of 2 columns or rows.
  • the indexes of the 2 elements with non-zero values may be idx_2, and idx_2 may be 2 values out of ⁇ 0, 1, 2, 3, 4, 5, 6, 7 ⁇ or ⁇ 1, 2, 3, 4, 5, 6, 7, 8 ⁇ .
  • idx_2 may be ⁇ 4, 5 ⁇ or ⁇ 1, 3 ⁇ or ⁇ 5, 6 ⁇ or ⁇ 2, 4 ⁇ .
  • the indexes of the 2 elements with non-zero values may be same in the third set of 2 columns or rows.
  • the indexes of the 2 elements with non-zero values may be idx_3, and idx_3 may be 2 values out of ⁇ 0, 1, 2, 3, 4, 5, 6, 7 ⁇ or ⁇ 1, 2, 3, 4, 5, 6, 7, 8 ⁇ .
  • idx_3 may be ⁇ 6, 7 ⁇ or ⁇ 5, 7 ⁇ or ⁇ 7, 8 ⁇ or ⁇ 6, 8 ⁇ .
  • any value of idx_1, any value of idx_2 and any value of idx_3 may be different from each other.
  • the values in a length-4 vector of the first set of length-4 vectors or of the second set of length-4 vectors may be applied for the 4 non-zero values mapping on 4 elements in a column or row in the first set of 4 columns or rows of the precoding matrix.
  • the first set of length-4 vectors may be ⁇ [1; 1; 1; 1] , [1; -1; 1; -1] , [1; 1; -1; -1] , [1; -1; -1; 1] ⁇ .
  • the second set of length-4 vectors may be ⁇ [1; 1; j; j] , [1; -1; j; -j] , [1; 1; -j; -j] , [1; -1; -j; j] ⁇ .
  • the 4 values in each vector of the first set or of the second set may be mapped on the 4 out of 8 elements, and 0 may be mapped on other 4 elements in a column or row of the precoding matrix.
  • the two values in a length-2 vector of the first set of length-2 vectors or of the second set of length-2 vectors may be applied as the two non-zero values mapping on 2 elements in a column or row of the second set of 2 columns or rows of the precoding matrix.
  • the two values in a length-2 vector of the first set of length-2 vectors or of the second set of length-2 vectors may be applied as the two non-zero values mapping on 2 elements in a column or row of the third set of 2 columns or rows of the precoding matrix.
  • the first set of the length-2 vectors may be ⁇ [1; 1] , [1; -1] ⁇ .
  • the second set of the length-2 vectors may be ⁇ [1; j] , [1; -j] ⁇ .
  • the 2 values in each vector of the first set or of the second set may be mapped on 2 out of 8 elements, and 0 may be mapped on other 6 elements in a column or row of the precoding matrix.
  • each column may be mapped with length-4 vectors, and for 2 out of remaining 4 columns, each column may be mapped with length-2 vectors, and f remaining 3 columns, each column may be mapped with length-2 vectors.
  • each of [a1, a2, a3, a4] , [b1, b2, b3, b4] , [c1, c2, c3, c4] and [d1, d2, d3, d4] may be one of the length-4 vectors in the first set of length-4 vectors or in the second set of length-4 vectors.
  • [a1, a2, a3, a4] , [b1, b2, b3, b4] , [c1, c2, c3, c4] and [d1, d2, d3, d4] may be [1; 1; 1; 1] , [1; -1; 1; -1] , [1; 1; -1; -1] and [1; -1; -1; 1] , respectively.
  • [a1, a2, a3, a4] , [b1, b2, b3, b4] , [c1, c2, c3, c4] and [d1, d2, d3, d4] may be [1; 1; j; j] , [1; -1; j; -j] , [1; 1; -j; -j] and [1; -1; -j; j] , respectively.
  • [e1, e2] , [f1, f2] may be [1; 1] , [1; -1] , respectively.
  • [e1, e2] , [f1, f2] may be [1; j] , [1; -j] , respectively.
  • [g1, g2] and [h1, h2] may be [1; 1] , [1; -1] , respectively.
  • [g1, g2] and [h1, h2] may be [1; j] , [1; -j] , respectively.
  • the terminal device 110 is indicated with the number of layers as 8, there may be a sixth set of precoding matrixes (for example, mixed partial and non coherent precoding matrixes) corresponding to 8 layers.
  • the structure of 8 antenna ports may be 4+1+1+1+1, which means that 4 antenna ports can be coherent, and remaining 4 antenna ports may be non-coherent.
  • rows or columns rows can be swapped.
  • each of [a1, a2, a3, a4] , [b1, b2, b3, b4] , [c1, c2, c3, c4] and [d1, d2, d3, d4] may be one of the length-4 vectors in the first set of length-4 vectors or in the second set of length-4 vectors.
  • [a1, a2, a3, a4] , [b1, b2, b3, b4] , [c1, c2, c3, c4] and [d1, d2, d3, d4] may be [1; 1; 1; 1] , [1; -1; 1; -1] , [1; 1; -1; -1] and [1; -1; -1; 1] , respectively.
  • [a1, a2, a3, a4] , [b1, b2, b3, b4] , [c1, c2, c3, c4] and [d1, d2, d3, d4] may be [1; 1; j; j] , [1; -1; j; -j] , [1; 1; -j; -j] and [1; -1; -j; j] , respectively.
  • the terminal device 110 may indicate with the number of layers as 8, there may be a seventh set of precoding matrixes (for example, mixed partial and non coherent precoding matrixes) corresponding to 8 layers.
  • the structure of the 8 ports may be 4+2+1+1, which means that 4 antenna ports can be coherent and 2 antenna ports can be coherent.
  • rows or columns can be swapped.
  • each of [a1, a2, a3, a4] , [b1, b2, b3, b4] , [c1, c2, c3, c4] and [d1, d2, d3, d4] may be one of the length-4 vectors in the first set of length-4 vectors or in the second set of length-4 vectors.
  • [a1, a2, a3, a4] , [b1, b2, b3, b4] , [c1, c2, c3, c4] and [d1, d2, d3, d4] may be [1; 1; 1; 1] , [1; -1; 1; -1] , [1; 1; -1; -1] and [1; -1; -1; 1] , respectively.
  • [a1, a2, a3, a4] , [b1, b2, b3, b4] , [c1, c2, c3, c4] and [d1, d2, d3, d4] may be [1; 1; j; j] , [1; -1; j; -j] , [1; 1; -j; -j] and [1; -1; -j; j] , respectively.
  • [e1, e2] , [f1, f2] may be [1; 1] , [1; -1] , respectively.
  • [e1, e2] , [f1, f2] may be [1; j] , [1; -j] , respectively.
  • the terminal device 110 is indicated with the number of layers as 8, there may be an eighth set of precoding matrixes (for example, mixed partial and non coherent precoding matrixes) corresponding to 8 layers.
  • the structure of the 8 ports may be 2+2+1+1+1+1, which means that 2 antenna ports can be coherent and 2 antenna ports can be coherent.
  • the antenna structure may be 2+1+1+1+1+1+1.
  • the antenna structure may be 2+2+2+1+1.
  • [a1, a2] , [b1, b2] may be [1; 1] , [1; -1] , respectively.
  • [a1, a2] , [b1, b2] may be [1; j] , [1; -j] , respectively.
  • [c1, c2] and [d1, d2] may be [1; 1] , [1; -1] , respectively.
  • [c1, c2] and [d1, d2] may be [1; j] , [1; -j] , respectively.
  • the terminal device 110 is indicated with the number of layers as 7, there may be a first set of precoding matrixes corresponding to 7 layers (e.g. a first set of full coherent precoding matrixes) , and a full coherent precoding matrix may be represented as
  • P may be 8 or 12 or 16.
  • l may be a non-negative integer. For example, 0 ⁇ l ⁇ O 1 N 1 . For another example, 0 ⁇ l ⁇ O 1 N 1 /2.
  • l may be at least one of ⁇ 0, 2, 4, 6, 8 ⁇ .
  • l may be at least one of ⁇ 0, 1, 2, 3 ⁇ .
  • l may be 0 or 1.
  • m may be a non-negative integer.
  • m may be at least one of ⁇ 0, 2, 4, 6, 8 ⁇ .
  • m may be at least one of ⁇ 0, 1, 2, 3 ⁇ .
  • n may be 0 or 1.
  • n may be 0.
  • n may be a non-negative integer.
  • n may be at least one of ⁇ 0, 1, 2, 3 ⁇ .
  • n may be 0 or 1.
  • n may be 0 or 2.
  • n may be 0.
  • l′ l+O 1 .
  • l′′ l+2O 1 .
  • l′′′ l+3O 1 .
  • m and m′and m′′ and m′′′ may be 0.
  • l′ l+O 1 .
  • l′′ l .
  • l′′′ l+O 1 .
  • m′ m .
  • m′′ m+O 2 .
  • m′′′ m+O 2 .
  • the first set of precoding matrixes corresponding to 7 layers may comprise more than one subset. For example, there may be two subsets of precoding matrixes.
  • l may be a non-negative integer, 0 ⁇ l ⁇ O 1 N 1 .
  • l may be at least one of ⁇ 0, 2, 4, 6 ⁇ .
  • l may be at least one of ⁇ 0, 1, 2, 3 ⁇ .
  • l may be 0 or 1.
  • l may be 0 or 2.
  • the number of precoding matrixes in the first subset corresponding to 7 layers may be 32 or 16 or 8 or 4 or 2.
  • the value of “O 2 ” may be 4 or 2 or 1.
  • l may be a non-negative integer, 0 ⁇ l ⁇ O 1 N 1 .
  • l may be at least one of ⁇ 0, 2, 4, 6 ⁇ .
  • l may be at least one of ⁇ 0, 1, 2, 3 ⁇ .
  • l may be 0 or 1.
  • l may be 0 or 2.
  • m may be a non-negative integer.
  • 0 ⁇ m ⁇ O 2 N 2 .
  • m may be at least one of ⁇ 0, 2, 4, 6, 8 ⁇ .
  • m may be at least one of ⁇ 0, 1, 2, 3 ⁇ .
  • m may be 0 or 1.
  • m may be 0.
  • the number of precoding matrixes in the second subset corresponding to 7 layers may be 128 or 32 or 16 or 8 or 4 or 2.
  • N 1 may equal to 4, N 2 equals to 1, O 1 may equal to 2 and O 2 may equal to 1 and i 1, 1 may be one of ⁇ 0, ...N 1 O 1 -1 ⁇ or ⁇ 0, 2, 4, 6 ⁇ or ⁇ 0, 4 ⁇ or ⁇ 0, 1 ⁇ or 0 or ⁇ 0, ...N 1 O 1 /2-1 ⁇ or ⁇ 0, 2 ⁇ .
  • the first subset of precoding matrixes corresponding to 7 layers (e.g. “Set_f7_1” ) may comprise 16 precoding matrixes.
  • the first subset of precoding matrixes “Set_f7_1” may comprise 8 precoding matrixes.
  • the first subset of precoding matrixes “Set_f7_1” may comprise 4 precoding matrixes.
  • the first subset of precoding matrixes “Set_f7_1” may comprise 2 precoding matrixes.
  • N 1 may equal to 2
  • N 2 equals to 2
  • O 1 may equal to 1 or 4
  • O 2 may equal to 2 or 4
  • i 1, 1 or i 1, 2 may be one of ⁇ 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 matrixes corresponding to 7 layers (e.g. “Set_f7_2” ) may comprise 128 precoding matrixes.
  • the second subset of precoding matrixes “Set_f7_2” may comprise 32 precoding matrixes.
  • the second subset of precoding matrixes “Set_f7_2” may comprise 8 precoding matrixes.
  • the second subset of precoding matrixes “Set_f7_2” may comprise 2 precoding matrixes.
  • the terminal device 110 is indicated with the number of layers as 7, there may be a second set of precoding matrixes corresponding to 7 layers (e.g. a second set of partial coherent precoding matrixes) .
  • a second set of precoding matrixes corresponding to 7 layers
  • 4 antenna ports e.g. a first set of 4 ports
  • the other 4 antenna ports e.g. a second set of 4 ports
  • the first set of 4 ports may not be coherent with the second set of 4 ports.
  • a second set of precoding matrixes (e.g. a second set of partial coherent precoding matrixes) corresponding to 7 layers, for example, represented as “Set_p7_1”
  • the size of a partial coherent precoding matrix may be 7 multiplies 8 or 8 multiplies 7.
  • 4 elements out of 8 elements in the partial coherent matrix may be with non-zero value.
  • the other 4 elements in the partial coherent precoding matrix may be with value of 0.
  • the indexes of the 4 elements with non-zero values may be same in the first set of 4 columns or rows.
  • the indexes of the 4 elements with non-zero values may be idx_1, and idx_1 may be 4 values out of ⁇ 0, 1, 2, 3, 4, 5, 6, 7 ⁇ or ⁇ 1, 2, 3, 4, 5, 6, 7, 8 ⁇ .
  • idx_1 may be ⁇ 0, 1, 2, 3 ⁇ or ⁇ 0, 2, 4, 6 ⁇ or ⁇ 1, 2, 3, 4 ⁇ or ⁇ 1, 3, 5, 7 ⁇ .
  • the 4 values of idx_1 may be based on the indexes of the 4 antenna ports in the first group.
  • non-zero values may be mapped on 4 out of 8 elements and 0 may be mapped on the other 4 elements.
  • the indexes of the 4 elements with non-zero values may be same in the second set of 3 columns or rows.
  • the indexes of the 4 elements with non-zero values may be idx_2, and idx_2 may be 4 values out of ⁇ 0, 1, 2, 3, 4, 5, 6, 7 ⁇ or ⁇ 1, 2, 3, 4, 5, 6, 7, 8 ⁇ .
  • the 4 values of idx_2 may be based on the indexes of the 4 antenna ports in the second group.
  • idx_2 may be ⁇ 4, 5, 6, 7 ⁇ or ⁇ 1, 3, 5, 7 ⁇ or ⁇ 5, 6, 7, 8 ⁇ or ⁇ 2, 4, 6, 8 ⁇ .
  • any value of idx_1 may be different from any value of idx_2.
  • each set may include 4 length-4 vectors.
  • the values in a length-4 vector may be applied for the 4 non-zero values mapping on 4 elements in a column or row of the precoding matrix.
  • the first set of length-4 vectors may be ⁇ [1; 1; 1; 1] , [1; -1; 1; -1] , [1; 1; - 1; -1] , [1; -1; -1; 1] ⁇ .
  • the second set of length-4 vectors may be ⁇ [1; 1; j; j] , [1; -1; j; -j] , [1; 1; -j; -j] , [1; -1; -j; j] ⁇ .
  • the 4 values in each vector of the first set or of the second set may be mapped on the 4 out of 8 elements, and 0 may be mapped on other 4 elements in a column or row of the precoding matrix.
  • the set of precoding matrixes “Set_p7_1” may comprise C (2, 1) *C (7, 4) *C (2, 1) *C (4, 3) precoding matrixes.
  • examples of a precoding matrix of the second set of precoding matrixes corresponding to 7 layers may be as:
  • each of [a1, a2, a3, a4] , [b1, b2, b3, b4] , [c1, c2, c3, c4] and [d1, d2, d3, d4] may be one of the length-4 vectors in the first set of length-4 vectors or in the second set of length-4 vectors.
  • each of [e1, e2, e3, e4] , [f1, f2, f3, f4] , [g1, g2, g3, g4] may be one of the length-4 vectors in the first set of length-4 vectors or in the second set of length-4 vectors.
  • [a1, a2, a3, a4] , [b1, b2, b3, b4] , [c1, c2, c3, c4] and [d1, d2, d3, d4] may be [1; 1; 1; 1] , [1; -1; 1; -1] , [1; 1; -1; -1] and [1; -1; -1; 1] , respectively.
  • [a1, a2, a3, a4] , [b1, b2, b3, b4] , [c1, c2, c3, c4] and [d1, d2, d3, d4] may be [1; 1; j; j] , [1; -1; j; -j] , [1; 1; -j; -j] and [1; -1; -j; j] , respectively.
  • [e1, e2, e3, e4] , [f1, f2, f3, f4] , [g1, g2, g3, g4] may be 3 vectors out of [1; 1; 1; 1] , [1; -1; 1; -1] , [1; 1; -1; -1] and [1; -1; -1; 1] .
  • [e1, e2, e3, e4] , [f1, f2, f3, f4] , [g1, g2, g3, g4] ] may be 3 vectors out of [1; 1; j; j] , [1; -1; j; -j] , [1; 1; -j; -j] and [1; -1; -j; j] .
  • s 7 may a positive integer. For example, 1 ⁇ s 7 ⁇ 64.
  • s 7 may be 64 or 32 or 16 or 8 or 4 or 2 or 56 or 28 or 14.
  • the terminal device 110 if the terminal device 110 is indicated with the number of layers as 7 , there may be a third set of precoding matrixes (e.g. a third set of partial coherent precoding matrixes) corresponding to 7 layers.
  • the structure of the 8 ports may be 2+2+2+2, which means that there are 4 groups, each group including 2 antenna ports and in each group, 2 antenna ports can be coherent. For example, between the groups, the antenna ports may not be coherent.
  • there may be a third set of precoding matrixes e.g.
  • a third set of partial coherent precoding matrixes for example, represented as “Set_p7_2”
  • the size of a precoding matrix may be 7 multiplies 8 or 8 multiplies 7.
  • 2 elements out of 8 elements in the precoding matrix may be with non-zero value.
  • the other 6 elements in the precoding matrix may be with value of 0.
  • there may be 2 columns or rows out of the 7 columns or rows e.g.
  • non-zero values may be mapped on 2 out of 8 elements and 0 may be mapped on the other 6 elements.
  • the indexes of the 2 elements with non-zero values may be same in the first set of 2 columns or rows.
  • the indexes of the 2 elements with non-zero values may be idx_1, and idx_1 may be 2 values out of ⁇ 0, 1, 2, 3, 4, 5, 6, 7 ⁇ or ⁇ 1, 2, 3, 4, 5, 6, 7, 8 ⁇ .
  • the 2 values of idx_1 may be based on the indexes of two out of the 4 antenna ports in the first group.
  • the 2 values of idx_1 may be based on the indexes of the 2 antenna ports in the third group.
  • idx_1 may be ⁇ 0, 1 ⁇ or ⁇ 0, 2 ⁇ or ⁇ 1, 2 ⁇ or ⁇ 1, 3 ⁇ or ⁇ 0, 4 ⁇ or ⁇ 1, 5 ⁇ .
  • the indexes of the 2 elements with non-zero values may be same in the second set of 2 columns or rows.
  • the indexes of the 2 elements with non-zero values may be idx_2, and idx_2 may be 2 values out of ⁇ 0, 1, 2, 3, 4, 5, 6, 7 ⁇ or ⁇ 1, 2, 3, 4, 5, 6, 7, 8 ⁇ .
  • the 2 values of idx_2 may be based on the indexes of the other two of the 4 antenna ports in the first group.
  • the 2 values of idx_2 may be based on the indexes of the 2 antenna ports in the fourth group.
  • idx_2 may be ⁇ 2, 3 ⁇ or ⁇ 1, 3 ⁇ or ⁇ 3, 4 ⁇ or ⁇ 2, 4 ⁇ or ⁇ 1, 5 ⁇ or ⁇ 2, 6 ⁇ .
  • the indexes of the 2 elements with non-zero values may be same in the third set of 2 columns or rows.
  • the indexes of the 2 elements with non-zero values may be idx_3, and idx_3 may be 2 values out of ⁇ 0, 1, 2, 3, 4, 5, 6, 7 ⁇ or ⁇ 1, 2, 3, 4, 5, 6, 7, 8 ⁇ .
  • the 2 values of idx_3 may be based on the indexes of two out of the 4 antenna ports in the second group. In some embodiments, the 2 values of idx_3 may be based on the indexes of the 2 antenna ports in the fifth group.
  • 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 column or row out of the 7 columns or rows (e.g.
  • non-zero values may be mapped on 2 out of 8 elements and 0 may be mapped on the other 6 elements.
  • the indexes of the 2 elements with non-zero values may be same in the fourth set of 1 column or row.
  • the indexes of the 2 elements with non-zero values may be idx_4, and idx_4 may be 2 values out of ⁇ 0, 1, 2, 3, 4, 5, 6, 7 ⁇ or ⁇ 1, 2, 3, 4, 5, 6, 7, 8 ⁇ .
  • the 2 values of idx_4 may be based on the indexes of remaining two of the 4 antenna ports in the second group.
  • the 2 values of idx_4 may be based on the indexes of the 2 antenna ports in the sixth group.
  • idx_4 may be ⁇ 6, 7 ⁇ or ⁇ 5, 7 ⁇ or ⁇ 7, 8 ⁇ or ⁇ 6, 8 ⁇ or ⁇ 3, 7 ⁇ or ⁇ 4, 8 ⁇ .
  • 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.
  • each one of the length-2 vector may be applied as the two non-zero values in a column or row of the precoding matrix.
  • two length-2 vectors can be selected from the 4 length-2 vectors, and the 2 values in each vector may be mapped on 2 out of 8 elements, and 0 may be mapped on other elements in a column or row of the precoding matrix.
  • the two values in a length-2 vector may be applied as the two non-zero values mapping on 2 elements in a column or row of the precoding matrix.
  • the first set of the length-2 vectors may be ⁇ [1; 1] , [1; -1] ⁇ .
  • the second set of the length-2 vectors may be ⁇ [1; j] , [1; -j] ⁇ .
  • the 2 values in each vector of the first set or of the second set may be mapped on 2 out of 8 elements, and 0 may be mapped on other 6 elements in a column or row of the precoding matrix.
  • the two vectors selected for mapping to 2 non-zero values on 2 elements out of 8 elements in each column or row may be ⁇ [1; 1] and [1; -1] ⁇ or ⁇ [1; j] and [1; -j] ⁇ .
  • examples of a precoding matrix of the third set of precoding matrixes corresponding to 7 layers may be as:
  • each of [a1, a2] , [b1, b2] may be one of the length-2 vectors in the first set of length-2 vectors or in the second set of length-2 vectors.
  • each of [c1, c2] and [d1, d2] may be one of the length-2 vectors in the first set of length-2 vectors or in the second set of length-2 vectors.
  • each of [e1, e2] , [f1, f2] may be one of the length-2 vectors in the first set of length-2 vectors or in the second set of length-2 vectors.
  • [g1, g2] may be one of the length-2 vectors in the first set of length-2 vectors or in the second set of length-2 vectors.
  • [a1, a2] , [b1, b2] may be [1; 1] , [1; -1] , respectively.
  • [a1, a2] , [b1, b2] may be [1; j] , [1; -j] , respectively.
  • [c1, c2] and [d1, d2] may be [1; 1] , [1; -1] , respectively.
  • [c1, c2] and [d1, d2] may be [1; j] , [1; -j] , respectively.
  • [e1, e2] , [f1, f2] may be [1; 1] , [1; -1] , respectively.
  • [e1, e2] , [f1, f2] may be [1; j] , [1; -j] , respectively.
  • [g1, g2] may be one of [1; 1] , [1; -1].
  • [g1, g2] may be one of [1; j] , [1; -j] , respectively.
  • a fourth set of precoding matrixes e.g. a fourth set of non-coherent precoding matrixes
  • each one of 8 antenna ports may be non-coherent with each other.
  • there may be a fourth set of precoding matrixes e.g. a fourth set of non-coherent precoding matrixes
  • the size of a precoding matrix may be 7 multiplies 8 or 8 multiplies 7.
  • 1 elements out of 8 elements in the precoding matrix may be with non-zero value.
  • the non-zero value may be 1.
  • the other 7 elements in the precoding matrix may be with value of 0.
  • the non-zero value may be mapped on 1 out of 8 elements and 0 may be mapped on the other 7 elements.
  • the indexes of the element with non-zero value may be different in each row or column of the precoding matrix.
  • the index of the 1 element with 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 column or row of the precoding matrix, respectively, and for each one of idx_1, idx_2, idx_3, idx_4, idx_5, idx_6, idx_7, 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 ⁇ .
  • the value 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.
  • the value 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.
  • the values of idx_1, idx_2, idx_3, idx_4 may be based on the indexes of the 4 antenna ports in the first group.
  • the values of idx_5, idx_6 and idx_7 may be based on the indexes of three out of the 4 antenna ports in the second group.
  • the values of idx_1, idx_2 may be based on the indexes of the 2 antenna ports in the third group.
  • the values of idx_3, idx_4 may be based on the indexes of the 2 antenna ports in the fourth group.
  • the values of idx_5, idx_6 may be based on the indexes of the 2 antenna ports in the fifth group.
  • the values of idx_7 may be based on the indexes of one out of the 2 antenna ports in the sixth group. For example, the value of idx_1, idx_2, idx_3, idx_4, idx_5, idx_6, idx_7 may be different from each other.
  • the terminal device 110 is indicated with number of layers is indicated as 7, there may be a fourth set of precoding matrixes corresponding to 7 layers.
  • the terminal device 110 if the terminal device 110 is indicated with the number of layers as 7, there may be a fifth set of precoding matrixes (for example, mixed partial coherent precoding matrixes) corresponding to 7 layers.
  • the structure of the 8 ports may 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.
  • 4 out of 8 columns may be mapped with length-4 vectors, and for remaining 3 columns, each column may be mapped with length-2 vectors, and with ports swapped.
  • the terminal device 110 if the terminal device 110 is indicated with the number of layers as 7, there may be a sixth set of precoding matrixes (for example, mixed partial and non coherent precoding matrixes) corresponding to 7 layers.
  • the structure of 8 antenna ports may be 4+1+1+1+1, which means that 4 antenna ports can be coherent.
  • the terminal device 110 if the terminal device 110 is indicated with the number of layers as 7, there may be a seventh set of precoding matrixes (for example, mixed partial and non coherent precoding matrixes) corresponding to 7 layers.
  • the structure of the 8 ports may be 4+2+1+1, which means that 4 antenna ports can be coherent and 2 antenna ports can be coherent.
  • the terminal device 110 if the terminal device 110 is indicated with the number of layers as 7, there may be an eighth set of precoding matrixes (for example, mixed partial and non coherent precoding matrixes) corresponding to 7 layers.
  • the structure of the 8 ports may be 2+2+1+1+1+1, which means that 2 antenna ports can be coherent and 2 antenna ports can be coherent.
  • the terminal device 110 is indicated with the number of layers as 6, there may be a first set of precoding matrixes corresponding to 6 layers (e.g. a first set of full coherent precoding matrixes) , and a full coherent precoding matrix may be represented as
  • P may be 8 or 12 or 16.
  • l may be a non-negative integer. For example, 0 ⁇ l ⁇ O 1 N 1 . For another example, 0 ⁇ l ⁇ O 1 N 1 /2.
  • l may be at least one of ⁇ 0, 2, 4, 6, 8 ⁇ .
  • l may be at least one of ⁇ 0, 1, 2, 3 ⁇ .
  • l may be 0 or 1.
  • m may be a non-negative integer.
  • m may be at least one of ⁇ 0, 2, 4, 6, 8 ⁇ .
  • m may be at least one of ⁇ 0, 1, 2, 3 ⁇ .
  • n may be 0 or 1.
  • n may be 0.
  • n may be a non-negative integer.
  • n may be at least one of ⁇ 0, 1, 2, 3 ⁇ .
  • n may be 0 or 1.
  • n may be 0 or 2.
  • n may be 0.
  • l′ l+O 1 .
  • l′′ l+2O 1 .
  • m and m′ and m′′ may be 0.
  • l′ l+O 1 .
  • l′′ l+O 1 .
  • m′ m.
  • m′′ m+O 2 .
  • the first set of precoding matrixes corresponding to 6 layers may comprise more than one subset. For example, there may be two subsets of precoding matrixes.
  • l may be a non-negative integer, 0 ⁇ l ⁇ O 1 N 1 .
  • l may be at least one of ⁇ 0, 2, 4, 6 ⁇ .
  • l may be at least one of ⁇ 0, 1, 2, 3 ⁇ .
  • l may be 0 or 1.
  • l may be 0 or 2.
  • the number of precoding matrixes in the first subset corresponding to 6 layers may be 32 or 16 or 8 or 4 or 2.
  • the value of “O 2 ” may be 4 or 2 or 1.
  • l may be a non-negative integer, 0 ⁇ l ⁇ O 1 N 1 .
  • l may be at least one of ⁇ 0, 2, 4, 6 ⁇ .
  • l may be at least one of ⁇ 0, 1, 2, 3 ⁇ .
  • l may be 0 or 1.
  • l may be 0 or 2.
  • m may be a non-negative integer.
  • 0 ⁇ m ⁇ O 2 N 2 .
  • m may be at least one of ⁇ 0, 2, 4, 6, 8 ⁇ .
  • m may be at least one of ⁇ 0, 1, 2, 3 ⁇ .
  • m may be 0 or 1.
  • m may be 0.
  • the number of precoding matrixes in the second subset corresponding to 6 layers may be 128 or 32 or 16 or 8 or 4 or 2.
  • N 1 may equal to 4, N 2 equals to 1, O 1 may equal to 2 and O 2 may equal to 1 and i 1, 1 may be one of ⁇ 0, ...N 1 O 1 -1 ⁇ or ⁇ 0, 2, 4, 6 ⁇ or ⁇ 0, 4 ⁇ or ⁇ 0, 1 ⁇ or 0 or ⁇ 0,...N 1 O 1 /2-1 ⁇ or ⁇ 0, 2 ⁇ .
  • the first subset of precoding matrixes corresponding to 6 layers, e.g. “Set_f6_1” may comprise 16 precoding matrixes.
  • the first subset of precoding matrixes “Set_f6_1” may comprise 8 precoding matrixes.
  • the first subset of precoding matrixes “Set_f6_1” may comprise 4 precoding matrixes.
  • the first subset of precoding matrixes “Set_f6_1” may comprise 2 precoding matrixes.
  • N 1 may equal to 2
  • N 2 equals to 2
  • O 1 may equal to 1 or 4
  • O 2 may equal to 2 or 4
  • i 1, 1 or i 1, 2 may be one of ⁇ 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 matrixes corresponding to 6 layers, e.g. “Set_f6_2” may comprise 128 precoding matrixes.
  • the second subset of precoding matrixes “Set_f6_2” may comprise 32 precoding matrixes.
  • the second subset of precoding matrixes “Set_f6_2” may comprise 8 precoding matrixes.
  • the second subset of precoding matrixes “Set_f6_2” may comprise 2 precoding matrixes.
  • the terminal device 110 is indicated with the number of layers as 6, there may be a second set of precoding matrixes corresponding to 6 layers (e.g. a second set of partial coherent precoding matrixes) .
  • a second set of precoding matrixes corresponding to 6 layers (e.g. a second set of partial coherent precoding matrixes) .
  • 4 antenna ports e.g. a first set of 4 ports
  • the other 4 antenna ports e.g. a second set of 4 ports
  • the first set of 4 ports may not be coherent with the second set of 4 ports.
  • a second set of precoding matrixes (e.g. a second set of partial coherent precoding matrixes) corresponding to 6 layers, for example, represented as “Set_p6_1”
  • the size of a partial coherent precoding matrix may be 6 multiplies 8 or 8 multiplies 6.
  • 4 elements out of 8 elements in the partial coherent matrix may be with non-zero value.
  • the other 4 elements in the partial coherent precoding matrix may be with value of 0.
  • the indexes of the 4 elements with non-zero values may be same in the first set of 4 columns or rows.
  • the indexes of the 4 elements with non-zero values may be idx_1, and idx_1 may be 4 values out of ⁇ 0, 1, 2, 3, 4, 5, 6, 7 ⁇ or ⁇ 1, 2, 3, 4, 5, 6, 7, 8 ⁇ .
  • idx_1 may be ⁇ 0, 1, 2, 3 ⁇ or ⁇ 0, 2, 4, 6 ⁇ or ⁇ 1, 2, 3, 4 ⁇ or ⁇ 1, 3, 5, 7 ⁇ .
  • the 4 values of idx_1 may be based on the indexes of of the 4 antenna ports in the first group.
  • 2 of the first set or the second set of length-4 vectors may be selected.
  • non-zero values may be mapped on 4 out of 8 elements and 0 may be mapped on the other 4 elements.
  • the indexes of the 4 elements with non-zero values may be same in the second set of 2 columns or rows.
  • the indexes of the 4 elements with non-zero values may be idx_2, and idx_2 may be 4 values out of ⁇ 0, 1, 2, 3, 4, 5, 6, 7 ⁇ or ⁇ 1, 2, 3, 4, 5, 6, 7, 8 ⁇ .
  • the 4 values of idx_2 may be based on the indexes of two out of the 4 antenna ports in the second group.
  • idx_2 may be ⁇ 4, 5, 6, 7 ⁇ or ⁇ 1, 3, 5, 7 ⁇ or ⁇ 5, 6, 7, 8 ⁇ or ⁇ 2, 4, 6, 8 ⁇ .
  • any value of idx_1 may be different from any value of idx_2.
  • 3 columns or rows out of the 6 columns or rows (e.g. a first set of 3 columns or rows) may be selected.
  • the non-zero value may be mapped on 4 out of 8 elements, and 0 may be mapped for other 4 elements.
  • the indexes of the 4 elements with non-zero values may be same in the first set of 3 columns or rows.
  • the indexes of the 4 elements with non-zero values may be idx_1, and idx_1 may be 4 values out of ⁇ 0, 1, 2, 3, 4, 5, 6, 7 ⁇ or ⁇ 1, 2, 3, 4, 5, 6, 7, 8 ⁇ .
  • the 4 values of idx_1 may be based on the indexes of of the 4 antenna ports in the first group.
  • idx_1 may be ⁇ 0, 1, 2, 3 ⁇ or ⁇ 0, 2, 4, 6 ⁇ or ⁇ 1, 2, 3, 4 ⁇ or ⁇ 1, 3, 5, 7 ⁇ .
  • 3 length-4 vectors of the first set or second set of length-4 vectors may be selected.
  • 3 of the first set or the second set of length-4 vectors may be selected.
  • for the other 3 columns or rows out of the 6 columns or rows e.g.
  • non-zero values may be mapped on 4 out of 8 elements and 0 may be mapped on the other 4 elements.
  • the indexes of the 4 elements with non-zero values may be same in the second set of 3 columns or rows.
  • the indexes of the 4 elements with non-zero values may be idx_2, and idx_2 may be 4 values out of ⁇ 0, 1, 2, 3, 4, 5, 6, 7 ⁇ or ⁇ 1, 2, 3, 4, 5, 6, 7, 8 ⁇ .
  • the 4 values of idx_2 may be based on the indexes of the 4 antenna ports in the first group.
  • idx_2 may be ⁇ 4,5, 6, 7 ⁇ or ⁇ 1, 3, 5, 7 ⁇ or ⁇ 5, 6, 7, 8 ⁇ or ⁇ 2, 4, 6, 8 ⁇ .
  • any value of idx_1 may be different from any value of idx_2.
  • each set may include 4 length-4 vectors.
  • the values in a length-4 vector may be applied for the 4 non-zero values mapping on 4 elements in a column or row of the precoding matrix.
  • the first set of length-4 vectors may be ⁇ [1; 1; 1; 1] , [1; -1; 1; -1] , [1; 1; -1; -1] , [1; -1; -1; 1] ⁇ .
  • the second set of length-4 vectors may be ⁇ [1; 1; j; j] , [1; -1; j; -j] , [1; 1; -j; -j] , [1; -1; -j; j] ⁇ .
  • the 4 values in each vector of the first set or of the second set may be mapped on the 4 out of 8 elements, and 0 may be mapped on other 4 elements in a column or row of the precoding matrix.
  • examples of a precoding matrix of the second set of precoding matrixes corresponding to 6 layers may be as:
  • rows or columns can be swapped.
  • rows or columns can be swapped.
  • each of [a1, a2, a3, a4] , [b1, b2, b3, b4] , [c1, c2, c3, c4] and [d1, d2, d3, d4] may be one of the length-4 vectors in the first set of length-4 vectors or in the second set of length-4 vectors.
  • each of [e1, e2, e3, e4] , [f1, f2, f3, f4] may be one of the length-4 vectors in the first set of length-4 vectors or in the second set of length-4 vectors.
  • [a1, a2, a3, a4] , [b1, b2, b3, b4] , [c1, c2, c3, c4] and [d1, d2, d3, d4] may be [1; 1; 1; 1] , [1; -1; 1; -1] , [1; 1; -1; -1] and [1; -1; -1; 1] , respectively.
  • [a1, a2, a3, a4] , [b1, b2, b3, b4] , [c1, c2, c3, c4] and [d1, d2, d3, d4] may be [1; 1; j; j] , [1; -1; j; -j] , [1; 1; -j; -j] and [1; -1; -j; j] , respectively.
  • [e1, e2, e3, e4] , [f1, f2, f3, f4] may be 2 vectors out of [1; 1; 1; 1] , [1; -1; 1; -1] , [1; 1; -1; -1] and [1; -1; -1; 1] .
  • [e1, e2, e3, e4] , [f1, f2, f3, f4] may be 2 vectors out of [1; 1; j; j] , [1; -1; j; -j] , [1; 1; -j; -j] and [1; -1; -j; j] .
  • each of [a1, a2, a3, a4] , [b1, b2, b3, b4] , [c1, c2, c3, c4] may be one of the length-4 vectors in the first set of length-4 vectors or in the second set of length-4 vectors.
  • each of [d1, d2, d3, d4] , [e1, e2, e3, e4] , [f1, f2, f3, f4] may be one of the length-4 vectors in the first set of length-4 vectors or in the second set of length-4 vectors.
  • [a1, a2, a3, a4] , [b1, b2, b3, b4] , [c1, c2, c3, c4] may be three vectors out of [1; 1; 1; 1] , [1; -1; 1; -1] , [1; 1; -1; -1] and [1; -1; -1; 1] .
  • [a1, a2, a3, a4] , [b1, b2, b3, b4] , [c1, c2, c3, c4] may be three of [1; 1; j; j] , [1; -1; j; -j] , [1; 1; -j; -j] and [1; -1; -j; j].
  • [d1, d2, d3, d4] , [e1, e2, e3, e4] , [f1, f2, f3, f4] may be 3 vectors out of [1; 1; 1; 1] , [1; -1; 1; -1] , [1; 1; -1; -1] and [1; -1; -1; 1] .
  • [d1, d2, d3, d4] , [e1, e2, e3, e4] , [f1, f2, f3, f4] may be 3 vectors out of [1; 1; j; j] , [1; -1; j; -j] , [1; 1; -j; -j] and [1; -1; -j; j] .
  • s 6 may a positive integer. For example, 1 ⁇ s 6 ⁇ 64.
  • s 6 may be 64 or 32 or 16 or 8 or 4 or 2 or 48 or 24 or 12.
  • the terminal device 110 if the terminal device 110 is indicated with the number of layers as 6 , there may be a third set of precoding matrixes (e.g. a third set of partial coherent precoding matrixes) corresponding to 6 layers.
  • the structure of the 8 ports may be 2+2+2+2, which means that there are 4 groups, each group including 2 antenna ports and in each group, 2 antenna ports can be coherent. For example, between the groups, the antenna ports may not be coherent.
  • there may be a third set of precoding matrixes e.g.
  • a third set of partial coherent precoding matrixes for example, represented as “Set_p6_2”
  • the size of a precoding matrix may be 6 multiplies 8 or 8 multiplies 6.
  • 2 elements out of 8 elements in the precoding matrix may be with non-zero value.
  • the other 6 elements in the precoding matrix may be with value of 0.
  • there may be 2 columns or rows out of the 6 columns or rows e.g.
  • non-zero values may be mapped on 2 out of 8 elements and 0 may be mapped on the other 6 elements.
  • the indexes of the 2 elements with non-zero values may be same in the first set of 2 columns or rows.
  • the indexes of the 2 elements with non-zero values may be idx_1, and idx_1 may be 2 values out of ⁇ 0, 1, 2, 3, 4, 5, 6, 7 ⁇ or ⁇ 1, 2, 3, 4, 5, 6, 7, 8 ⁇ .
  • the 2 values of idx_1 may be based on the indexes of two out of the 4 antenna ports in the first group.
  • the 2 values of idx_1 may be based on the indexes of the 2 antenna ports in the third group.
  • idx_1 may be ⁇ 0, 1 ⁇ or ⁇ 0, 2 ⁇ or ⁇ 1, 2 ⁇ or ⁇ 1, 3 ⁇ or ⁇ 0, 4 ⁇ or ⁇ 1, 5 ⁇ .
  • the indexes of the 2 elements with non-zero values may be same in the second set of 2 columns or rows.
  • the indexes of the 2 elements with non-zero values may be idx_2, and idx_2 may be 2 values out of ⁇ 0, 1, 2, 3, 4, 5, 6, 7 ⁇ or ⁇ 1, 2, 3, 4, 5, 6, 7, 8 ⁇ .
  • the 2 values of idx_2 may be based on the indexes of remaining two of the 4 antenna ports in the first group.
  • the 2 values of idx_2 may be based on the indexes of the 2 antenna ports in the fourth group.
  • idx_2 may be ⁇ 2, 3 ⁇ or ⁇ 1, 3 ⁇ or ⁇ 3, 4 ⁇ or ⁇ 2, 4 ⁇ or ⁇ 1, 5 ⁇ or ⁇ 2, 6 ⁇ .
  • the indexes of the 2 elements with non-zero values may be same in the third set of 1 or 2 columns or rows.
  • the indexes of the 2 elements with non-zero values may be idx_3, and idx_3 may be 2 values out of ⁇ 0, 1, 2, 3, 4, 5, 6, 7 ⁇ or ⁇ 1, 2, 3, 4, 5, 6, 7, 8 ⁇ .
  • the 2 values of idx_1 may be based on the indexes of two out of the 4 antenna ports in the second group. In some embodiments, the 2 values of idx_1 may be based on the indexes of the 2 antenna ports in the fifth group.
  • idx_3 may be ⁇ 4, 5 ⁇ or ⁇ 4, 6 ⁇ or ⁇ 5, 6 ⁇ or ⁇ 5, 7 ⁇ or ⁇ 2, 6 ⁇ or ⁇ 3, 7 ⁇ .
  • non-zero values may be mapped on 2 out of 8 elements and 0 may be mapped on the other 6 elements.
  • the indexes of the 2 elements with non-zero values may be same in the fourth set of 1 or 2 columns or rows.
  • the indexes of the 2 elements with non-zero values may be idx_4, and idx_4 may be 2 values out of ⁇ 0, 1, 2, 3, 4, 5, 6, 7 ⁇ or ⁇ 1, 2, 3, 4, 5, 6, 7, 8 ⁇ .
  • the 2 values of idx_4 may be based on the indexes of remaining two of the 4 antenna ports in the second group.
  • the 2 values of idx_4 may be based on the indexes of the 2 antenna ports in the sixth group.
  • idx_4 may be ⁇ 6, 7 ⁇ or ⁇ 5, 7 ⁇ or ⁇ 7, 8 ⁇ or ⁇ 6, 8 ⁇ or ⁇ 3, 7 ⁇ or ⁇ 4, 8 ⁇ .
  • 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.
  • the total number of columns or rows in the first set and/or the second set and/or the third set and/or the fourth set may be 6.
  • first set there may be the first set, the second set and the third set, and each set with 2 columns or rows. In some embodiments, there may be the first set, the second set and the third set and fourth set, and each of two of the four sets with 2 columns or rows, and each of other two of the four sets with 1 column or row.
  • each one of the length-2 vector may be applied as the two non-zero values in a column or row of the precoding matrix.
  • two length-2 vectors can be selected from the 4 length-2 vectors, and the 2 values in each vector may be mapped on 2 out of 8 elements, and 0 may be mapped on other elements in a column or row of the precoding matrix.
  • the two values in a length-2 vector may be applied as the two non-zero values mapping on 2 elements in a column or row of the precoding matrix.
  • the first set of the length-2 vectors may be ⁇ [1; 1] , [1; -1] ⁇ .
  • the second set of the length-2 vectors may be ⁇ [1; j] , [1; -j] ⁇ .
  • the 2 values in each vector of the first set or of the second set may be mapped on 2 out of 8 elements, and 0 may be mapped on other 6 elements in a column or row of the precoding matrix.
  • the two vectors selected for mapping to 2 non-zero values on 2 elements out of 8 elements in each column or row may be ⁇ [1; 1] and [1; -1] ⁇ or ⁇ [1; j] and [1; -j] ⁇ .
  • examples of a precoding matrix of the third set of precoding matrixes corresponding to 6 layers may be as:
  • each of [a1, a2] , [b1, b2] may be one of the length-2 vectors in the first set of length-2 vectors or in the second set of length-2 vectors.
  • each of [c1, c2] and [d1, d2] may be one of the length-2 vectors in the first set of length-2 vectors or in the second set of length-2 vectors.
  • each of [e1, e2] , [f1, f2] may be one of the length-2 vectors in the first set of length-2 vectors or in the second set of length-2 vectors.
  • [a1, a2] , [b1, b2] may be [1; 1] , [1; -1] , respectively.
  • [a1, a2] , [b1, b2] may be [1; j] , [1; -j] , respectively.
  • [c1, c2] and [d1, d2] may be [1; 1] , [1; -1] , respectively.
  • [c1, c2] and [d1, d2] may be [1; j] , [1; -j] , respectively.
  • [e1, e2] , [f1, f2] may be [1; 1] , [1; -1] , respectively.
  • [e1, e2] , [f1, f2] may be [1; j] , [1; -j] , respectively.
  • [e1, e2] may be one of [1; 1] , [1; -1] , [1; j] , [1; -j] .
  • [f1, f2] may be one of [1; 1] , [1; -1] , [1; j] , [1; -j] .
  • the terminal device 110 if the terminal device 110 is indicated with the number of layers as 6, there may be a fourth set of precoding matrixes (e.g. a fourth set of non-coherent precoding matrixes) corresponding to 6 layers. For example, each one of 8 antenna ports may be non-coherent with each other.
  • there may be a fourth set of precoding matrixes e.g. a fourth set of non-coherent precoding matrixes
  • the size of a precoding matrix may be 6 multiplies 8 or 8 multiplies 6.
  • 1 elements out of 8 elements in the precoding matrix may be with non-zero value.
  • the non-zero value may be 1.
  • the other 7 elements in the precoding matrix may be with value of 0.
  • the non-zero value may be mapped on 1 out of 8 elements and 0 may be mapped on the other 7 elements.
  • the indexes of the element with non-zero value may be different in each row or column of the precoding matrix.
  • the index of the 1 element with 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 column or row of the precoding matrix, respectively, and for each one of idx_1, idx_2, idx_3, idx_4, idx_5, idx_6 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 ⁇ .
  • the values of idx_1, idx_2, idx_3, idx_4 may be based on the indexes of the 4 antenna ports in the first group. In some embodiments, the values of idx_1, idx_2, idx_3 may be based on the indexes of the three out of 4 antenna ports in the first group. In some embodiments, the values of idx_1 and idx_2 may be based on the indexes of 2 antenna ports in the third group. In some embodiments, the values of idx_3 and idx_4 may be based on the indexes of the 2 antenna ports in the fourth group.
  • the values of idx_5, idx_6 may be based on the indexes of two out of the 4 antenna ports in the second group. In some embodiments, the values of idx_5, idx_6 may be based on the indexes of the 2 antenna ports in the fifth group. In some embodiments, the values of idx_5, idx_6 may be based on the indexes of the 2 antenna ports in the sixth group. For example, the value of idx_1, idx_2, idx_3, idx_4, idx_5, idx_6 may be 0, 1, 2, 3, 4, 5, respectively.
  • the value of idx_1, idx_2, idx_3, idx_4, idx_5, idx_6 may be 1, 2, 3, 4, 5, 6, respectively.
  • the value of idx_1, idx_2, idx_3, idx_4, idx_5, idx_6 may be different from each other.
  • the terminal device 110 is indicated with number of layers is indicated as 6, there may be a fourth set of precoding matrixes corresponding to 6 layers. For example, there may be only one precoding matrix in the fourth set (e.g. non-coherent precoding matrix) corresponding to 6 layers.
  • a mixed partial coherent matrix may be supported.
  • the antenna structure may 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.
  • r1 for example, 2, 3, or 4 columns may be mapped with length-4 vectors, and 6-r1 column may be mapped with length-2 vectors, and with ports swapped.
  • the antenna structure may be 4+1+1+1+1, which means that 4 antenna ports can be coherent.
  • r1 for example, 2 or 3 or 4
  • columns may be with length-4 vectors
  • 6-r1 columns may be with 1 on one element
  • rows can be swap.
  • the antenna structure may be 4+2+1+1, which means that 4 antenna ports can be coherent and 2 antenna ports can be coherent.
  • r1 for example, 2 or 3 or 4
  • r2 for example, 0, 1, 2 columns may be with length-2 vectors
  • 6-r1-r2 columns may be with 1 on one element.
  • the antenna structure may be 2+2+1+1+1+1, which means that 2 antenna ports can be coherent and 2 antenna ports can be coherent.
  • r1 for example, 2 or 3 or 4
  • columns may be with length-2 vectors
  • 6-r1 columns may be with 1 on one element.
  • the terminal device 110 is indicated with the number of layers as 5, there may be a first set of precoding matrixes corresponding to 5 layers (e.g. a first set of full coherent precoding matrixes) , and a full coherent precoding matrix may be represented as
  • P may be 8 or 12 or 16.
  • l may be a non-negative integer. For example, 0 ⁇ l ⁇ O 1 N 1 . For another example, 0 ⁇ l ⁇ O 1 N 1 /2.
  • l may be at least one of ⁇ 0, 2, 4, 6, 8 ⁇ .
  • l may be at least one of ⁇ 0, 1, 2, 3 ⁇ .
  • l may be 0 or 1.
  • m may be a non-negative integer.
  • m may be at least one of ⁇ 0, 2, 4, 6, 8 ⁇ .
  • m may be at least one of ⁇ 0, 1, 2, 3 ⁇ .
  • n may be 0 or 1.
  • n may be 0.
  • n may be a non-negative integer.
  • n may be at least one of ⁇ 0, 1, 2, 3 ⁇ .
  • n may be 0 or 1.
  • n may be 0 or 2.
  • n may be 0.
  • l′ l+O 1 .
  • l′′ l+2O 1 .
  • m and m′ and m′′ may be 0.
  • l′ l+O 1 .
  • l′′ l+O 1 .
  • m′ m.
  • m′′ m+O 2 .
  • the first set of precoding matrixes corresponding to 5 layers may comprise more than one subset. For example, there may be two subsets of precoding matrixes.
  • l may be a non-negative integer, 0 ⁇ l ⁇ O 1 N 1 .
  • l may be at least one of ⁇ 0, 2, 4, 6 ⁇ .
  • l may be at least one of ⁇ 0, 1, 2, 3 ⁇ .
  • l may be 0 or 1.
  • l may be 0 or 2.
  • the number of precoding matrixes in the first subset corresponding to 5 layers may be 32 or 16 or 8 or 4 or 2.
  • the value of “O 2 ” may be 4 or 2 or 1.
  • l may be a non-negative integer, 0 ⁇ l ⁇ O 1 N 1 .
  • l may be at least one of ⁇ 0, 2, 4, 6 ⁇ .
  • l may be at least one of ⁇ 0, 1, 2, 3 ⁇ .
  • l may be 0 or 1.
  • l may be 0 or 2.
  • m may be a non-negative integer.
  • 0 ⁇ m ⁇ O 2 N 2 .
  • m may be at least one of ⁇ 0, 2, 4, 6, 8 ⁇ .
  • m may be at least one of ⁇ 0, 1, 2, 3 ⁇ .
  • m may be 0 or 1.
  • m may be 0.
  • the number of precoding matrixes in the second subset corresponding to 5 layers may be 128 or 32 or 16 or 8 or 4 or 2.
  • N 1 may equal to 4, N 2 equals to 1, O 1 may equal to 2 and O 2 may equal to 1 and i 1, 1 may be one of ⁇ 0, ...N 1 O 1 -1 ⁇ or ⁇ 0, 2, 4, 6 ⁇ or ⁇ 0, 4 ⁇ or ⁇ 0, 1 ⁇ or 0 or ⁇ 0,...N 1 O 1 /2-1 ⁇ or ⁇ 0, 2 ⁇ .
  • the first subset of precoding matrixes corresponding to 5 layers, e.g. “Set_f5_1” may comprise 16 precoding matrixes.
  • the first subset of precoding matrixes “Set_f5_1” may comprise 8 precoding matrixes.
  • the first subset of precoding matrixes “Set_f5_1” may comprise 4 precoding matrixes.
  • the first subset of precoding matrixes “Set_f5_1” may comprise 2 precoding matrixes.
  • N 1 may equal to 2
  • N 2 equals to 2
  • O 1 may equal to 1 or 4
  • O 2 may equal to 2 or 4
  • i 1, 1 or i 1, 2 may be one of ⁇ 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 matrixes corresponding to 5 layers, e.g. “Set_f5_2” may comprise 128 precoding matrixes.
  • the second subset of precoding matrixes “Set_f5_2” may comprise 32 precoding matrixes.
  • the second subset of precoding matrixes “Set_f5_2” may comprise 8 precoding matrixes.
  • the second subset of precoding matrixes “Set_f5_2” may comprise 2 precoding matrixes.
  • the terminal device 110 is indicated with the number of layers as 5, there may be a second set of precoding matrixes corresponding to 5 layers (e.g. a second set of partial coherent precoding matrixes) .
  • a second set of precoding matrixes corresponding to 5 layers (e.g. a second set of partial coherent precoding matrixes) .
  • the terminal device 110 has 8 antenna ports or if a PUSCH transmission of the terminal device 110 is associated with 8 antenna ports or if a PUSCH transmission of the terminal device 110 is associated with SRS with 8 ports, 4 antenna ports (e.g. a first set of 4 ports) may be coherent and the other 4 antenna ports (e.g. a second set of 4 ports) may be coherent.
  • the first set of 4 ports may not be coherent with the second set of 4 ports.
  • a second set of precoding matrixes (e.g. a second set of partial coherent precoding matrixes) corresponding to 5 layers, for example, represented as “Set_p5_1”
  • the size of a partial coherent precoding matrix may be 5 multiplies 8 or 8 multiplies 5.
  • 4 elements out of 8 elements in the partial coherent matrix may be with non-zero value.
  • the other 4 elements in the partial coherent precoding matrix may be with value of 0.
  • C1 columns or rows out of the 5 columns or rows (e.g. a first set of C1 columns or rows.
  • C1 may be 1 or 2 or 3 or 4) in the precoding matrix, and in each column, the non-zero value may be mapped on 4 out of 8 elements and 0 for the other 4 elements.
  • the indexes of the 4 elements with non-zero values may be same in the first set of C1 columns or rows.
  • the indexes of the 4 elements with non-zero values may be idx_1, and idx_1 may be 4 values out of ⁇ 0, 1, 2, 3, 4, 5, 6, 7 ⁇ or ⁇ 1, 2, 3, 4, 5, 6, 7, 8 ⁇ .
  • the 4 values of idx_1 may be based on the indexes of the 4 antenna ports in the first group.
  • idx_1 may be ⁇ 0, 1, 2, 3 ⁇ or ⁇ 0, 2, 4, 6 ⁇ or ⁇ 1, 2, 3, 4 ⁇ or ⁇ 1, 3, 5, 7 ⁇ .
  • 5-C1 of the first set or second set of length-4 vectors may be selected.
  • non-zero values may be mapped on 4 out of 8 elements and 0 may be mapped on the other 4 elements.
  • the indexes of the 4 elements with non-zero values may be same in the second set of 5-C1 columns or rows.
  • the indexes of the 4 elements with non-zero values may be idx_2, and idx_2 may be 4 values out of ⁇ 0, 1, 2, 3, 4, 5, 6, 7 ⁇ or ⁇ 1, 2, 3, 4, 5, 6, 7, 8 ⁇ .
  • the 4 values of idx_2 may be based on the indexes of the 4 antenna ports in the second group.
  • idx_2 may be ⁇ 4,5, 6, 7 ⁇ or ⁇ 1, 3, 5, 7 ⁇ or ⁇ 5, 6, 7, 8 ⁇ or ⁇ 2, 4, 6, 8 ⁇ .
  • any value of idx_1 may be different from any value of idx_2.
  • 3 columns may be selected. In each column, the non-zero value may be mapped on 4 out of 8 elements, and 0 may be mapped for other 4 elements. For other 2 columns, one matrix and 2 vectors may be selected.
  • each set may include 4 length-4 vectors.
  • the values in a length-4 vector may be applied for the 4 non-zero values mapping on 4 elements in a column or row of the precoding matrix.
  • the first set of length-4 vectors may be ⁇ [1; 1; 1; 1] , [1; -1; 1; -1] , [1; 1; -1; -1] , [1; -1; -1; 1] ⁇ .
  • the second set of length-4 vectors may be ⁇ [1; 1; j; j] , [1; -1; j; -j] , [1; 1; -j; -j] , [1; -1; -j; j] ⁇ .
  • the 4 values in each vector of the first set or of the second set may be mapped on the 4 out of 8 elements, and 0 may be mapped on other 4 elements in a column or row of the precoding matrix.
  • examples of a precoding matrix of the second set of precoding matrixes corresponding to 5 layers may be as:
  • rows or columns can be swapped.
  • rows or columns can be swapped.
  • each of [a1, a2, a3, a4] , [b1, b2, b3, b4] , [c1, c2, c3, c4] and [d1, d2, d3, d4] may be one of the length-4 vectors in the first set of length-4 vectors or in the second set of length-4 vectors.
  • [e1, e2, e3, e4] may be one of the length-4 vectors in the first set of length-4 vectors or in the second set of length-4 vectors.
  • [a1, a2, a3, a4] , [b1, b2, b3, b4] , [c1, c2, c3, c4] and [d1, d2, d3, d4] may be [1; 1; 1; 1] , [1; -1; 1; -1] , [1; 1; -1; -1] and [1; -1; -1; 1] , respectively.
  • [a1, a2, a3, a4] , [b1, b2, b3, b4] , [c1, c2, c3, c4] and [d1, d2, d3, d4] may be [1; 1; j; j] , [1; -1; j; -j] , [1; 1; -j; -j] and [1; -1; -j; j] , respectively.
  • [e1, e2, e3, e4] may be 1 vector out of [1; 1; 1; 1] , [1; -1; 1; -1] , [1; 1; -1; -1] and [1; -1; -1; 1] .
  • [e1, e2, e3, e4] may be 1 vector out of [1; 1; j; j] , [1; -1; j; -j] , [1; 1; -j; -j] and [1; -1; -j; j] .
  • each of [a1, a2, a3, a4] , [b1, b2, b3, b4] , [c1, c2, c3, c4] may be one of the length-4 vectors in the first set of length-4 vectors or in the second set of length-4 vectors.
  • each of [d1, d2, d3, d4] , [e1, e2, e3, e4] may be one of the length-4 vectors in the first set of length-4 vectors or in the second set of length-4 vectors.
  • [a1, a2, a3, a4] , [b1, b2, b3, b4] , [c1, c2, c3, c4] may be three vectors out of [1; 1; 1; 1] , [1; -1; 1; -1] , [1; 1; -1; -1] and [1; -1; -1; 1] .
  • [a1, a2, a3, a4] , [b1, b2, b3, b4] , [c1, c2, c3, c4] may be three of [1; 1; j; j] , [1; -1; j; -j] , [1; 1; -j; -j] and [1; -1; -j; j] .
  • [d1, d2, d3, d4] , [e1, e2, e3, e4] may be 2 vectors out of [1; 1; 1; 1] , [1; -1; 1; -1] , [1; 1; -1; -1] and [1; -1; -1; 1] .
  • [d1, d2, d3, d4] , [e1, e2, e3, e4] may be 2 vectors out of [1; 1; j; j] , [1; -1; j; -j] , [1; 1; -j; -j] and [1; -1; -j; j] .
  • s 5 may a positive integer. For example, 1 ⁇ s 5 ⁇ 64.
  • s 5 may be 64 or 32 or 16 or 8 or 4 or 2 or 40 or 20 or 10.
  • the terminal device 110 if the terminal device 110 is indicated with the number of layers as 5 , there may be a third set of precoding matrixes (e.g. a third set of partial coherent precoding matrixes) corresponding to 5 layers.
  • the structure of the 8 ports may be 2+2+2+2, which means that there are 4 groups, each group including 2 antenna ports and in each group, 2 antenna ports can be coherent. For example, between the groups, the antenna ports may not be coherent.
  • there may be a third set of precoding matrixes e.g.
  • a third set of partial coherent precoding matrixes for example, represented as “Set_p5_2”
  • the size of a precoding matrix may be 5 multiplies 8 or 8 multiplies 5.
  • 2 elements out of 8 elements in the precoding matrix may be with non-zero value.
  • the other 6 elements in the precoding matrix may be with value of 0.
  • there may be 2 columns or rows out of the 5 columns or rows e.g.
  • non-zero values may be mapped on 2 out of 8 elements and 0 may be mapped on the other 6 elements.
  • the indexes of the 2 elements with non-zero values may be same in the first set of 2 columns or rows.
  • the indexes of the 2 elements with non-zero values may be idx_1, and idx_1 may be 2 values out of ⁇ 0, 1, 2, 3, 4, 5, 6, 7 ⁇ or ⁇ 1, 2, 3, 4, 5, 6, 7, 8 ⁇ .
  • the 2 values of idx_1 may be based on the indexes of two out of the 4 antenna ports in the first group.
  • the 2 values of idx_1 may be based on the indexes of the 2 antenna ports in the third group.
  • idx_1 may be ⁇ 0, 1 ⁇ or ⁇ 0, 2 ⁇ or ⁇ 1, 2 ⁇ or ⁇ 1, 3 ⁇ or ⁇ 0, 4 ⁇ or ⁇ 1, 5 ⁇ .
  • the indexes of the 2 elements with non-zero values may be same in the second set of 1 or 2 columns or rows.
  • the indexes of the 2 elements with non-zero values may be idx_2, and idx_2 may be 2 values out of ⁇ 0, 1, 2, 3, 4, 5, 6, 7 ⁇ or ⁇ 1, 2, 3, 4, 5, 6, 7, 8 ⁇ .
  • the 2 values of idx_2 may be based on the indexes of remaining two of the 4 antenna ports in the first group.
  • the 2 values of idx_2 may be based on the indexes of the 2 antenna ports in the fourth group.
  • idx_2 may be ⁇ 2, 3 ⁇ or ⁇ 1, 3 ⁇ or ⁇ 3, 4 ⁇ or ⁇ 2, 4 ⁇ or ⁇ 1, 5 ⁇ or ⁇ 2, 6 ⁇ .
  • the indexes of the 2 elements with non-zero values may be same in the third set of 1 or 2 columns or rows.
  • the indexes of the 2 elements with non-zero values may be idx_3, and idx_3 may be 2 values out of ⁇ 0, 1, 2, 3, 4, 5, 6, 7 ⁇ or ⁇ 1, 2, 3, 4, 5, 6, 7, 8 ⁇ .
  • the 2 values of idx_3 may be based on the indexes of two out of the 4 antenna ports in the second group.
  • the 2 values of idx_3 may be based on the indexes of the 2 antenna ports in the fifth group.
  • idx_3 may be ⁇ 4, 5 ⁇ or ⁇ 4, 6 ⁇ or ⁇ 5, 6 ⁇ or ⁇ 5, 7 ⁇ or ⁇ 2, 6 ⁇ or ⁇ 3, 7 ⁇ .
  • the indexes of the 2 elements with non-zero values may be same in the fourth set of 1 or 2 columns or rows.
  • the indexes of the 2 elements with non-zero values may be idx_4, and idx_4 may be 2 values out of ⁇ 0, 1, 2, 3, 4, 5, 6, 7 ⁇ or ⁇ 1, 2, 3, 4, 5, 6, 7, 8 ⁇ .
  • the 2 values of idx_4 may be based on the indexes of remaining two of the 4 antenna ports in the second group. In some embodiments, the 2 values of idx_4 may be based on the indexes of the 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.
  • the total number of columns or rows in the first set and/or the second set and/or the third set and/or the fourth set may be 5. In some embodiments, there may be the first set, the second set and the third set, and each of two of the three sets with 2 columns or rows, and one of the three sets with 1 column or row. In some embodiments, there may be the first set, the second set, the third set and the fourth set, and one of the four sets with 2 columns or rows, and each of three of the fourth sets with 1 column or row.
  • each one of the length-2 vector may be applied as the two non-zero values in a column or row of the precoding matrix.
  • two length-2 vectors can be selected from the 4 length-2 vectors, and the 2 values in each vector may be mapped on 2 out of 8 elements, and 0 may be mapped on other elements in a column or row of the precoding matrix.
  • the two values in a length-2 vector may be applied as the two non-zero values mapping on 2 elements in a column or row of the precoding matrix.
  • the first set of the length-2 vectors may be ⁇ [1; 1] , [1; -1] ⁇ .
  • the second set of the length-2 vectors may be ⁇ [1; j] , [1; -j] ⁇ .
  • the 2 values in each vector of the first set or of the second set may be mapped on 2 out of 8 elements, and 0 may be mapped on other 6 elements in a column or row of the precoding matrix.
  • the two vectors selected for mapping to 2 non-zero values on 2 elements out of 8 elements in each column or row may be ⁇ [1; 1] and [1; -1] ⁇ or ⁇ [1; j] and [1; -j] ⁇ .
  • examples of a precoding matrix of the third set of precoding matrixes corresponding to 5 layers may be as:
  • each of [a1, a2] , [b1, b2] may be one of the length-2 vectors in the first set of length-2 vectors or in the second set of length-2 vectors.
  • each of [c1, c2] and [d1, d2] may be one of the length-2 vectors in the first set of length-2 vectors or in the second set of length-2 vectors.
  • [e1, e2] may be one of the length-2 vectors in the first set of length-2 vectors or in the second set of length-2 vectors.
  • [a1, a2] , [b1, b2] may be [1; 1] , [1; -1] , respectively.
  • [a1, a2] , [b1, b2] may be [1; j] , [1; -j] , respectively.
  • [c1, c2] and [d1, d2] may be [1; 1] , [1; -1] , respectively.
  • [c1, c2] and [d1, d2] may be [1; j] , [1; -j] , respectively.
  • [c1, c2] , [d1, d2] , [e1, e2] may be any one of [1; 1] , [1; -1] , [1; j] , [1; -j] .
  • the terminal device 110 if the terminal device 110 is indicated with the number of layers as 5, there may be a fourth set of precoding matrixes (e.g. a fourth set of non-coherent precoding matrixes) corresponding to 5 layers. For example, each one of 8 antenna ports may be non-coherent with each other.
  • there may be a fourth set of precoding matrixes e.g. a fourth set of non-coherent precoding matrixes
  • the size of a precoding matrix may be 5 multiplies 8 or 8 multiplies 5.
  • 1 elements out of 8 elements in the precoding matrix may be with non-zero value.
  • the non-zero value may be 1.
  • the other 7 elements in the precoding matrix may be with value of 0.
  • the non-zero value may be mapped on 1 out of 8 elements and 0 may be mapped on the other 7 elements.
  • the indexes of the element with non-zero value may be different in each row or column of the precoding matrix.
  • the index of the 1 element with non-zero value may be idx_1, idx_2, idx_3, idx_4, idx_5 for the first, second, third, fourth, fifth column or row of the precoding matrix, respectively, and for each one 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 ⁇ .
  • the value of idx_1, idx_2, idx_3, idx_4, idx_5 may be 0, 1, 2, 3, 4, respectively.
  • the value of idx_1, idx_2, idx_3, idx_4, idx_5, may be 1, 2, 3, 4, 5, respectively.
  • the value of idx_1, idx_2, idx_3, idx_4, idx_5 may be different from each other.
  • the terminal device 110 is indicated with number of layers is indicated as 5, there may be a fourth set of precoding matrixes corresponding to 5 layers.
  • a mixed partial coherent matrix may be supported.
  • the antenna structure may 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.
  • r1 for example, 1, 2, 3, or 4
  • columns may be mapped with length-4 vectors
  • 5-r1 column may be mapped with length-2 vectors, and with ports swapped.
  • the antenna structure may be 4+1+1+1+1, which means that 4 antenna ports can be coherent.
  • r1 for example, 1 or 2 or 3 or 4
  • columns may be with length-4 vectors
  • 5-r1 columns may be with 1 on one element
  • rows can be swap.
  • the antenna structure may be 4+2+1+1, which means that 4 antenna ports can be coherent and 2 antenna ports can be coherent.
  • r1 for example, 1or 2 or 3 or 4
  • r2 for example, 0, 1, 2 columns
  • 5-r1-r2 columns may be with 1 on one element.
  • the antenna structure may be 2+2+1+1+1+1, which means that 2 antenna ports can be coherent and 2 antenna ports can be coherent.
  • r1 for example, 1 or 2 or 3 or 4
  • columns may be with length-2 vectors
  • 5-r1 columns may be with 1 on one element.
  • the terminal device 110 is indicated with the number of layers as 4, there may be a first set of precoding matrixes corresponding to 4 layers (e.g. a first set of full coherent precoding matrixes) .
  • a full coherent precoding matrix may be represented as
  • P may be 8 or 12 or 16.
  • l may be a non-negative integer. For example, 0 ⁇ l ⁇ O 1 N 1 . For another example, 0 ⁇ l ⁇ O 1 N 1 /2.
  • l may be at least one of ⁇ 0, 2, 4, 6, 8 ⁇ .
  • l may be at least one of ⁇ 0, 1, 2, 3 ⁇ .
  • l may be 0 or 1.
  • m may be a non-negative integer.
  • m may be at least one of ⁇ 0, 2, 4, 6, 8 ⁇ .
  • m may be at least one of ⁇ 0, 1, 2, 3 ⁇ .
  • n may be 0 or 1.
  • n may be 0.
  • n may be a non-negative integer.
  • n may be at least one of ⁇ 0, 1, 2, 3 ⁇ .
  • n may be 0 or 1.
  • n may be 0 or 2.
  • n may be 0.
  • l′ l+k 1 .
  • m′ m+k 2 .
  • k 1 may be a non-negative integer.
  • k 1 may at least one of ⁇ 0, O 1 , 2O 1 , 3O 1 ⁇ .
  • k 1 may be 0.
  • k 2 may be a non-negative integer.
  • k 2 may at least one of ⁇ 0, O 2 ⁇ .
  • k 2 may be 0.
  • i 1, 3 there may be a parameter i 1, 3 , and the value of k 1 and/or k 2 may be based on the value of i 1, 3 , and i 1, 3 may be a non-negative integer.
  • i 1, 3 may be at least one of ⁇ 0, 1, 2, 3 ⁇ .
  • i 1, 3 may be 0 or 1.
  • i 1, 3 may be 0.
  • the first set of precoding matrixes corresponding to 4 layers may comprise more than one subset. For example, there may be two or three or four subsets of precoding matrixes.
  • corresponding to the first subset In some embodiments, corresponding to the first subset, m and m′ may be 0.
  • corresponding to the first subset, l′ l+k 1 .
  • corresponding to the first subset, l may be a non-negative integer, 0 ⁇ l ⁇ O 1 N 1 .
  • l may be at least one of ⁇ 0, 2, 4, 6 ⁇ .
  • l may be at least one of ⁇ 0, 1, 2, 3 ⁇ .
  • l may be 0 or 1.
  • l may be 0 or 2.
  • the number of precoding matrixes in the first subset corresponding to 4 layers may be 128 or 64 or 32 or 16 or 8 or 4 or 2.
  • the value of “O 2 ” may be 4 or 2 or 1.
  • l may be at least one of ⁇ 0, 2, 4, 6 ⁇ .
  • l may be at least one of ⁇ 0, 1, 2, 3 ⁇ .
  • l may be 0 or 1.
  • l may be 0 or 2.
  • m may be a non-negative integer. For example, 0 ⁇ m ⁇ O 2 N 2 .
  • m may be at least one of ⁇ 0, 2, 4, 6 ⁇ .
  • m may be at least one of ⁇ 0, 1, 2, 3 ⁇ .
  • m may be 0 or 1.
  • m may be 0.
  • the number of precoding matrixes in the second subset corresponding to 4 layers may be 256 or 128 or 32 or 16 or 8 or 4 or 2.
  • N 1 may equal to 4, N 2 equals to 1, O 1 may equal to 4 or 2 or 1 and O 2 may equal to 1 and i 1, 1 may be one of ⁇ 0, ...N 1 O 1 -1 ⁇ or ⁇ 0, 2, 4, 6 ⁇ or ⁇ 0, 4 ⁇ or ⁇ 0, 1 ⁇ or 0 or ⁇ 0, ...N 1 O 1 /2-1 ⁇ or ⁇ 0, 2 ⁇ .
  • the first subset of precoding matrixes corresponding to 4 layers, e.g. “Set_f4_1” may comprise 16 precoding matrixes.
  • the first subset of precoding matrixes “Set_f4_1” may comprise 8 precoding matrixes.
  • the first subset of precoding matrixes “Set_f4_1” may comprise 4 precoding matrixes.
  • the first subset of precoding matrixes “Set_f4_1” may comprise 2 precoding matrixes.
  • N 1 may equal to 2
  • N 2 may equal to 2
  • O 1 may equal to 1 or 2 or 4
  • O 2 may equal to 1 or 2 or 4
  • i 1, 3 may be 0 or 1 or 2 or 3
  • i 1, 1 or i 1, 2 may be one of ⁇ 0, ...3 ⁇ or ⁇ 0, 2 ⁇ or 0.
  • the second subset of precoding matrixes corresponding to 4 layers e.g. “Set_f4_2” may comprise 32 precoding matrixes.
  • the second subset of precoding matrixes “Set_f4_2” may comprise 8 precoding matrixes.
  • the second subset of precoding matrixes “Set_f4_2” may comprise 2 precoding matrixes.
  • p there may be a second factor a p .
  • p may be a non-negative integer.
  • p may be at least one of ⁇ 0, 1, 2, 3 ⁇ .
  • p may be 0 or 1.
  • p may be 0 or 2.
  • p may be 0.
  • n_b may be a non-negative integer.
  • n_b may be at least one of ⁇ 0, 1, 2, 3 ⁇ .
  • n_b may be 0 or 1.
  • n_b may be 0 or 2.
  • n_b may be 0.
  • l may be a non-negative integer. For example, 0 ⁇ l ⁇ O 1 N 1 .
  • l may be at least one of ⁇ 0, 2 ⁇ .
  • l may be at least one of ⁇ 0, 1, 2, 3 ⁇ .
  • l may be 0 or 1.
  • the value of p 1 may be at least one of ⁇ 0, 1, 2, 3 ⁇ or ⁇ 0, 1 ⁇ or ⁇ 0, 2 ⁇ .
  • the value of p 1 may be 0.
  • the value of n may be at least one of ⁇ 0, 1, 2, 3 ⁇ or ⁇ 0, 1 ⁇ or ⁇ 0, 2 ⁇ .
  • the value of n may be 0.
  • i 1, 3 there may be a parameter i 1, 3 , and the value of k 1 and/or k 2 may be based on the value of i 1, 3 , and i 1, 3 may be a non-negative integer.
  • i 1, 3 may be at least one of ⁇ 0, 1 ⁇ .
  • i 1, 3 may be 0.
  • the value of “O 2 ” may be 1.
  • corresponding to the third subset In some embodiments, corresponding to the third subset, m and m′ may be 0.
  • corresponding to the third subset, l′ l+k 1 .
  • corresponding to the third subset, l may be a non-negative integer, 0 ⁇ l ⁇ O 1 N 1 .
  • l may be at least one of ⁇ 0, 1, 2, 3 ⁇ .
  • l may be 0 or 1.
  • l may be 0 or 2.
  • the number of precoding matrixes in the third subset corresponding to 4 layers may be 64 or 32 or 16 or 8 or 4 or 2.
  • k 1 may be O 1 or 0.
  • corresponding to the third subset, m′ m+k 2 .
  • k 2 may be 0.
  • p may be p 1 .
  • l may be a non-negative integer. For example, 0 ⁇ l ⁇ O 1 N 1 .
  • l may be at least one of ⁇ 0, 2 ⁇ .
  • l may be at least one of ⁇ 0, 1, 2, 3 ⁇ .
  • l may be 0 or 1.
  • the value of p 1 may be at least one of ⁇ 0, 1, 2, 3 ⁇ or ⁇ 0, 1 ⁇ or ⁇ 0, 2 ⁇ . In some embodiments, the value of p 1 may be 0.
  • the value of “O 2 ” may be 1.
  • corresponding to the fourth subset, corresponding to the fourth subset, m and m′ may be 0.
  • corresponding to the fourth subset, l′ l+k 1 .
  • corresponding to the fourth subset, l may be a non-negative integer, 0 ⁇ l ⁇ O 1 N 1 .
  • l may be at least one of ⁇ 0, 1, 2, 3 ⁇ .
  • l may be 0 or 1.
  • l may be 0 or 2.
  • the number of precoding matrixes in the fourth subset corresponding to 4 layers may be 64 or 32 or 16 or 8 or 4 or 2.
  • the terminal device 110 is indicated with the number of layers is indicated as 4, there may be a second set of precoding matrixes corresponding to 4 layers (e.g. a second set of partial coherent precoding matrixes) .
  • a second set of precoding matrixes corresponding to 4 layers.
  • the terminal device 110 has 8 antenna ports or if a PUSCH transmission of the terminal device 110 is associated with 8 antenna ports or if a PUSCH transmission of the terminal device 110 is associated with SRS with 8 ports
  • 4 antenna ports e.g. a first set of 4 ports
  • the other 4 antenna ports e.g. a second set of 4 ports
  • the first set of 4 ports may not be coherent with the second set of 4 ports.
  • a second set of precoding matrixes (e.g. a second set of partial coherent precoding matrixes) corresponding to 4 layers, for example, represented as “Set_p4_1”
  • the size of a partial coherent precoding matrix may be 4 multiplies 8 or 8 multiplies 4.
  • 4 elements out of 8 elements in the partial coherent matrix may be with non-zero value.
  • the other 4 elements in the partial coherent precoding matrix may be with value of 0.
  • C2 columns or rows out of the 4 columns or rows (e.g. a first set of C2 columns or rows.
  • C2 may be 1 or 2 or 3 or 4) in the precoding matrix, and in each column, the non-zero value may be mapped on 4 out of 8 elements and 0 for the other 4 elements.
  • the indexes of the 4 elements with non-zero values may be same in the first set of C2 columns or rows.
  • the indexes of the 4 elements with non-zero values may be idx_1, and idx_1 may be 4 values out of ⁇ 0, 1, 2, 3, 4, 5, 6, 7 ⁇ or ⁇ 1, 2, 3, 4, 5, 6, 7, 8 ⁇ .
  • the 4 values of idx_1 may be based on the indexes of the 4 antenna ports in the first group.
  • idx_1 may be ⁇ 0, 1, 2, 3 ⁇ or ⁇ 0, 2, 4, 6 ⁇ or ⁇ 1, 2, 3, 4 ⁇ or ⁇ 1, 3, 5, 7 ⁇ .
  • 4-C2 of the first set or second set of length-4 vectors may be selected.
  • non-zero values may be mapped on 4 out of 8 elements and 0 may be mapped on the other 4 elements.
  • the indexes of the 4 elements with non-zero values may be same in the second set of 4-C2 columns or rows.
  • the indexes of the 4 elements with non-zero values may be idx_2, and idx_2 may be 4 values out of ⁇ 0, 1, 2, 3, 4, 5, 6, 7 ⁇ or ⁇ 1, 2, 3, 4, 5, 6, 7, 8 ⁇ .
  • the 4 values of idx_2 may be based on the indexes of the 4 antenna ports in the second group.
  • idx_2 may be ⁇ 4, 5, 6, 7 ⁇ or ⁇ 1, 3, 5, 7 ⁇ or ⁇ 5, 6, 7, 8 ⁇ or ⁇ 2, 4, 6, 8 ⁇ .
  • any value of idx_1 may be different from any value of idx_2.
  • C2 may be 4 and there may be no second set of columns or rows.
  • each set may include 4 length-4 vectors.
  • the values in a length-4 vector may be applied for the 4 non-zero values mapping on 4 elements in a column or row of the precoding matrix.
  • the first set of length-4 vectors may be ⁇ [1; 1; 1; 1] , [1; -1; 1; -1] , [1; 1; -1; -1] , [1; -1; -1; 1] ⁇ .
  • the second set of length-4 vectors may be ⁇ [1; 1; j; j] , [1; -1; j; -j] , [1; 1; -j; -j] , [1; -1; -j; j] ⁇ .
  • the 4 values in each vector of the first set or of the second set may be mapped on the 4 out of 8 elements, and 0 may be mapped on other 4 elements in a column or row of the precoding matrix.
  • examples of a precoding matrix of the second set of precoding matrixes corresponding to 4 layers may be as:
  • rows or columns can be swapped.
  • rows or columns can be swapped.
  • each of [a1, a2, a3, a4] , [b1, b2, b3, b4] , [c1, c2, c3, c4] and [d1, d2, d3, d4] may be one of the length-4 vectors in the first set of length-4 vectors or in the second set of length-4 vectors.
  • [a1, a2, a3, a4] , [b1, b2, b3, b4] , [c1, c2, c3, c4] and [d1, d2, d3, d4] may be [1; 1; 1; 1] , [1; -1; 1; -1] , [1; 1; -1; -1] and [1; -1; -1; 1] , respectively.
  • [a1, a2, a3, a4] , [b1, b2, b3, b4] , [c1, c2, c3, c4] and [d1, d2, d3, d4] may be [1; 1; j; j] , [1; -1; j; -j] , [1; 1; -j; -j] and [1; -1; -j; j] , respectively.
  • each of [a1, a2, a3, a4] , [b1, b2, b3, b4] , [c1, c2, c3, c4] may be one of the length-4 vectors in the first set of length-4 vectors or in the second set of length-4 vectors.
  • [d1, d2, d3, d4] may be one of the length-4 vectors in the first set of length-4 vectors or in the second set of length-4 vectors.
  • [a1, a2, a3, a4] , [b1, b2, b3, b4] may be two vectors out of [1; 1; 1; 1] , [1; -1; 1; -1] , [1; 1; -1; -1] and [1; -1; -1; 1] .
  • [a1, a2, a3, a4] , [b1, b2, b3, b4] may be two of [1; 1; j; j] , [1; -1; j; -j] , [1; 1; -j; -j] and [1; -1; -j; j] .
  • [c1, c2, c3, c4] , [d1, d2, d3, d4] may be 2 vectors out of [1; 1; 1; 1] , [1; -1; 1; -1] , [1; 1; -1; -1] and [1; -1; -1; 1] .
  • [c1, c2, c3, c4] , [d1, d2, d3, d4] may be 2 vectors out of [1; 1; j; j] , [1; -1; j; -j] , [1; 1; -j; -j] and [1; -1; -j; j] .
  • s 4 may a positive integer. For example, 1 ⁇ s 4 ⁇ 64.
  • s 4 may be 64 or 32 or 16 or 8 or 4 or 2 or 32 or 16 or 8.
  • N g may equal to 2
  • N 1 may equal to 2
  • N 2 equals to 1
  • O 1 may equal to 2 or 4
  • i 1, 3 may be 0, and i 1, 1 may be one of ⁇ 0, ...N1O1-1 ⁇ or ⁇ 0, 2, 4, 6 ⁇ or ⁇ 0, 4 ⁇ or ⁇ 0, 2 ⁇ or ⁇ 0, 1 ⁇ or 0, or i 1, 4, 1 may be one of ⁇ 0, 1, 2, 3 ⁇ or ⁇ 0, 2 ⁇ or 0.
  • the third subset of precoding matrixes corresponding to 4 layers, e.g. “Set_f4_3” may comprise 64 precoding matrixes.
  • the third subset of precoding matrixes “Set_f4_3” may comprise 32 precoding matrixes.
  • the third subset of precoding matrixes “Set_f4_3” may comprise 16 precoding matrixes.
  • the third subset of precoding matrixes “Set_f4_3” may comprise 8 precoding matrixes.
  • the third subset of precoding matrixes “Set_f4_3” may comprise 4 precoding matrixes.
  • the third subset of precoding matrixes “Set_f4_3” may comprise 2 precoding matrixes.
  • N g may equal to 2
  • N 1 may equal to 2
  • N 2 equals to 1
  • O 1 may equal to 2 or 4
  • i 1, 3 may be 0, and i 1, 1 may be one of ⁇ 0, ...N 1 O 1 -1 ⁇ or ⁇ 0, 2, 4, 6 ⁇ or ⁇ 0, 4 ⁇ or ⁇ 0, 2 ⁇ or ⁇ 0, 1 ⁇ , or i 1, 4, q may be one of ⁇ 0, 1, 2, 3 ⁇ or ⁇ 0, 2 ⁇ or 0, where q may be 0 or 1.
  • the fourth subset of precoding matrixes corresponding to 4 layers, e.g. “Set_f4_4” may comprise 256 precoding matrixes.
  • the fourth subset of precoding matrixes “Set_f4_4” may comprise 128 precoding matrixes. In some embodiments, the fourth subset of precoding matrixes “Set_f4_4” may comprise 64 precoding matrixes. In some embodiments, the fourth subset of precoding matrixes “Set_f4_4” may comprise 32 precoding matrixes. The fourth subset of precoding matrixes “Set_f4_4” may comprise 16 precoding matrixes. In some embodiments, the fourth subset of precoding matrixes “Set_f4_4” may comprise 8 precoding matrixes. Alternatively, the fourth subset of precoding matrixes “Set_f4_4” may comprise 4 precoding matrixes. In other embodiments, the fourth subset of precoding matrixes “Set_f4_4” may comprise 2 precoding matrixes.
  • the terminal device 110 is indicated with the number of layers is indicated as 4 , there may be a third set of precoding matrixes (e.g. a third set of partial coherent precoding matrixes) corresponding to 4 layers.
  • the structure of the 8 ports may be 2+2+2+2, which means that there are 4 groups, each group including 2 antenna ports and in each group, 2 antenna ports can be coherent. For example, between the groups, the antenna ports may not be coherent.
  • there may be a third set of precoding matrixes e.g.
  • a third set of partial coherent precoding matrixes for example, represented as “Set_p4_2”
  • the size of a precoding matrix may be 4 multiplies 8 or 8 multiplies 4.
  • 2 elements out of 8 elements in the precoding matrix may be with non-zero value.
  • the other 6 elements in the precoding matrix may be with value of 0.
  • there may be 1 or 2 columns or rows out of the 4 columns or rows e.g.
  • non-zero values may be mapped on 2 out of 8 elements and 0 may be mapped on the other 6 elements.
  • the indexes of the 2 elements with non-zero values may be same in the first set of 1 or 2 columns or rows.
  • the indexes of the 2 elements with non-zero values may be idx_1, and idx_1 may be 2 values out of ⁇ 0, 1, 2, 3, 4, 5, 6, 7 ⁇ or ⁇ 1, 2, 3, 4, 5, 6, 7, 8 ⁇ .
  • the 2 values of idx_1 may be based on the indexes of two out of the 4 antenna ports in the first group.
  • the 2 values of idx_1 may be based on the indexes of the 2 antenna ports in the third group.
  • idx_1 may be ⁇ 0, 1 ⁇ or ⁇ 0, 2 ⁇ or ⁇ 1, 2 ⁇ or ⁇ 1, 3 ⁇ or ⁇ 0, 4 ⁇ or ⁇ 1, 5 ⁇ .
  • the indexes of the 2 elements with non-zero values may be same in the second set of 1 or 2 columns or rows.
  • the indexes of the 2 elements with non-zero values may be idx_2, and idx_2 may be 2 values out of ⁇ 0, 1, 2, 3, 4, 5, 6, 7 ⁇ or ⁇ 1, 2, 3, 4, 5, 6, 7, 8 ⁇ .
  • the 2 values of idx_2 may be based on the indexes of remaining two of the 4 antenna ports in the first group.
  • the 2 values of idx_2 may be based on the indexes of the 2 antenna ports in the fourth group.
  • idx_2 may be ⁇ 2, 3 ⁇ or ⁇ 1, 3 ⁇ or ⁇ 3, 4 ⁇ or ⁇ 2, 4 ⁇ or ⁇ 1, 5 ⁇ or ⁇ 2, 6 ⁇ .
  • the indexes of the 2 elements with non-zero values may be same in the third set of 1 or 2 columns or rows.
  • the indexes of the 2 elements with non-zero values may be idx_3, and idx_3 may be 2 values out of ⁇ 0, 1, 2, 3, 4, 5, 6, 7 ⁇ or ⁇ 1, 2, 3, 4, 5, 6, 7, 8 ⁇ .
  • the 2 values of idx_3 may be based on the indexes of two out of the 4 antenna ports in the second group.
  • the 2 values of idx_3 may be based on the indexes of the 2 antenna ports in the fifth group.
  • idx_3 may be ⁇ 4, 5 ⁇ or ⁇ 4, 6 ⁇ or ⁇ 5, 6 ⁇ or ⁇ 5, 7 ⁇ or ⁇ 2, 6 ⁇ or ⁇ 3, 7 ⁇ .
  • the indexes of the 2 elements with non-zero values may be same in the fourth set of 1 or 2 columns or rows.
  • the indexes of the 2 elements with non-zero values may be idx_4, and idx_4 may be 2 values out of ⁇ 0, 1, 2, 3, 4, 5, 6, 7 ⁇ or ⁇ 1, 2, 3, 4, 5, 6, 7, 8 ⁇ .
  • the 2 values of idx_4 may be based on the indexes of remaining two out of the 4 antenna ports in the second group. In some embodiments, the 2 values of idx_4 may be based on the indexes of the 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.
  • the total number of columns or rows in the first set and/or the second set and/or the third set and/or the fourth set may be 4. In some embodiments, there may be the first set and the second set, and each set with 2 columns or rows. In some embodiments, there may be the first set, the second set and the third set, and each of two of the three sets with 2 columns or rows, and one of the three sets with 1 column or row. In some embodiments, there may be the first set, the second set, the third set and the fourth set, and each set with 1 column or row.
  • each one of the length-2 vector may be applied as the two non-zero values in a column or row of the precoding matrix.
  • two length-2 vectors can be selected from the 4 length-2 vectors, and the 2 values in each vector may be mapped on 2 out of 8 elements, and 0 may be mapped on other elements in a column or row of the precoding matrix.
  • the two values in a length-2 vector may be applied as the two non-zero values mapping on 2 elements in a column or row of the precoding matrix.
  • the first set of the length-2 vectors may be ⁇ [1; 1] , [1; -1] ⁇ .
  • the second set of the length-2 vectors may be ⁇ [1; j] , [1; -j] ⁇ .
  • the 2 values in each vector of the first set or of the second set may be mapped on 2 out of 8 elements, and 0 may be mapped on other 6 elements in a column or row of the precoding matrix.
  • the two vectors selected for mapping to 2 non-zero values on 2 elements out of 8 elements in each column or row may be ⁇ [1; 1] and [1; -1] ⁇ or ⁇ [1; j] and [1; -j] ⁇ .
  • examples of a precoding matrix of the third set of precoding matrixes corresponding to 4 layers may be as:
  • each of [a1, a2] , [b1, b2] may be one of the length-2 vectors in the first set of length-2 vectors or in the second set of length-2 vectors.
  • each of [c1, c2] and [d1, d2] may be one of the length-2 vectors in the first set of length-2 vectors or in the second set of length-2 vectors.
  • [a1, a2] , [b1, b2] may be [1; 1] , [1; -1] , respectively.
  • [a1, a2] , [b1, b2] may be [1; j] , [1; -j] , respectively.
  • [c1, c2] and [d1, d2] may be [1; 1] , [1; -1] , respectively.
  • [c1, c2] and [d1, d2] may be [1; j] , [1; -j] , respectively.
  • [a1, a2] , [b1, b2] , [c1, c2] , [d1, d2] may be any one of [1; 1] , [1; -1] , [1; j] , [1; -j] .
  • the terminal device 110 is indicated with the number of layers is indicated as 4, there may be a fourth set of precoding matrixes (e.g. a fourth set of non-coherent precoding matrixes) corresponding to 4 layers.
  • a fourth set of precoding matrixes e.g. a fourth set of non-coherent precoding matrixes
  • the size of a precoding matrix may be 4 multiplies 8 or 8 multiplies 4.
  • 1 elements out of 8 elements in the precoding matrix may be with non-zero value.
  • the non-zero value may be 1.
  • the other 7 elements in the precoding matrix may be with value of 0.
  • the non-zero value may be mapped on 1 out of 8 elements and 0 may be mapped on the other 7 elements.
  • the indexes of the element with non-zero value may be different in each row or column of the precoding matrix.
  • the index of the 1 element with non-zero value may be idx_1, idx_2, idx_3, idx_4 for the first, second, third, fourth column or row of the precoding matrix, respectively, and for each one 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 ⁇ .
  • the value 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.
  • the value 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.
  • the value of idx_1, idx_2, idx_3, idx_4 may be different from each other.
  • the values of idx_1, idx_2, idx_3, idx_4 may be based on the indexes of the 4 antenna ports in the first group or the second group.
  • the terminal device 110 is indicated with number of layers as 4 there may be a fourth set of precoding matrixes corresponding to 4 layers.
  • a mixed partial coherent matrix may be supported.
  • the antenna structure may 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.
  • r1 for example, 1, 2, or 3 columns may be mapped with length-4 vectors, and 4-r1 column may be mapped with length-2 vectors, and with ports swapped.
  • the antenna structure may be 4+1+1+1+1, which means that 4 antenna ports can be coherent.
  • r1 for example, 1 or 2 or 3 columns may be with length-4 vectors, 4-r1 columns may be with 1 on one element, and rows can be swap.
  • the antenna structure may be 4+2+1+1, which means that 4 antenna ports can be coherent and 2 antenna ports can be coherent.
  • r1 for example, 1 or 2 columns may be with length-4 vectors
  • r2 for example, 1 or 2 columns may be with length-2 vectors
  • 4-r1-r2 columns may be with 1 on one element.
  • the antenna structure may be 2+2+1+1+1+1, which means that 2 antenna ports can be coherent and 2 antenna ports can be coherent.
  • r1 for example, 1 or 2 or 3 columns may be with length-2 vectors, and 4-r1 columns may be with 1 on one element.
  • the antenna structure may be 2+1+1+1+1+1+1.
  • the antenna structure may be 2+2+2+1+1.
  • the terminal device 110 is indicated with the number of layers as 3, there may be a first set of precoding matrixes corresponding to 3 layers (e.g. a first set of full coherent precoding matrixes) .
  • a full coherent precoding matrix may be represented as
  • P may be 8 or 12 or 16.
  • l may be a non-negative integer. For example, 0 ⁇ l ⁇ O 1 N 1 . For another example, 0 ⁇ l ⁇ O 1 N 1 /2.
  • l may be at least one of ⁇ 0, 2, 4, 6, 8 ⁇ .
  • l may be at least one of ⁇ 0, 1, 2, 3 ⁇ .
  • l may be 0 or 1.
  • m may be a non-negative integer.
  • m may be at least one of ⁇ 0, 2, 4, 6, 8 ⁇ .
  • m may be at least one of ⁇ 0, 1, 2, 3 ⁇ .
  • n may be 0 or 1.
  • n may be 0.
  • n may be a non-negative integer.
  • n may be at least one of ⁇ 0, 1, 2, 3 ⁇ .
  • n may be 0 or 1.
  • n may be 0 or 2.
  • n may be 0.
  • l′ l+k 1 .
  • m′ m+k 2 .
  • k 1 may be a non-negative integer.
  • k 1 may at least one of ⁇ 0, O 1 , 2O 1 , 3O 1 ⁇ .
  • k 1 may be 0.
  • k 2 may be a non-negative integer.
  • k 2 may at least one of ⁇ 0, O 2 ⁇ .
  • k 2 may be 0.
  • i 1, 3 there may be a parameter i 1, 3 , and the value of k 1 and/or k 2 may be based on the value of i 1, 3 , and i 1, 3 may be a non-negative integer.
  • i 1, 3 may be at least one of ⁇ 0, 1, 2, 3 ⁇ .
  • i 1, 3 may be 0 or 1.
  • i 1, 3 may be 0.
  • the first set of precoding matrixes corresponding to 3 layers may comprise more than one subset. For example, there may be two or three or four subsets of precoding matrixes.
  • corresponding to the first subset In some embodiments, corresponding to the first subset, m and m′ may be 0.
  • corresponding to the first subset, l′ l+k 1 .
  • corresponding to the first subset, l may be a non-negative integer, 0 ⁇ l ⁇ O 1 N 1 .
  • l may be at least one of ⁇ 0, 2, 4, 6 ⁇ .
  • l may be at least one of ⁇ 0, 1, 2, 3 ⁇ .
  • l may be 0 or 1.
  • l may be 0 or 2.
  • the number of precoding matrixes in the first subset corresponding to 3 layers may be 128 or 64 or 32 or 16 or 8 or 4 or 2.
  • the value of “O 2 ” may be 4 or 2 or 1.
  • l may be at least one of ⁇ 0, 2, 4, 6 ⁇ .
  • l may be at least one of ⁇ 0, 1, 2, 3 ⁇ .
  • l may be 0 or 1.
  • l may be 0 or 2.
  • m may be a non-negative integer. For example, 0 ⁇ m ⁇ O 2 N 2 .
  • m may be at least one of ⁇ 0, 2, 4, 6 ⁇ .
  • m may be at least one of ⁇ 0, 1, 2, 3 ⁇ .
  • m may be 0 or 1.
  • m may be 0.
  • the number of precoding matrixes in the second subset corresponding to 3 layers may be 256 or 128 or 32 or 16 or 8 or 4 or 2.
  • l may be a non-negative integer. For example, 0 ⁇ l ⁇ O 1 N 1 .
  • l may be at least one of ⁇ 0, 2 ⁇ .
  • l may be at least one of ⁇ 0, 1, 2, 3 ⁇ .
  • l may be 0 or 1.
  • the value of p 1 may be at least one of ⁇ 0, 1, 2, 3 ⁇ or ⁇ 0, 1 ⁇ or ⁇ 0, 2 ⁇ . In some embodiments, the value of p 1 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.
  • i 1, 3 there may be a parameter i 1, 3 , and the value of k 1 and/or k 2 may be based on the value of i 1, 3 , and i 1, 3 may be a non-negative integer.
  • i 1, 3 may be at least one of ⁇ 0, 1 ⁇ .
  • i 1, 3 may be 0.
  • the value of “O 2 ” may be 1.
  • corresponding to the third subset In some embodiments, corresponding to the third subset, m and m′ may be 0.
  • corresponding to the third subset, l′ l+k 1 .
  • corresponding to the third subset, l may be a non-negative integer, 0 ⁇ l ⁇ O 1 N 1 .
  • l may be at least one of ⁇ 0, 1, 2, 3 ⁇ .
  • l may be 0 or 1.
  • l may be 0 or 2.
  • the number of precoding matrixes in the third subset corresponding to 3 layers may be 64 or 32 or 16 or 8 or 4 or 2.
  • l may be a non-negative integer. For example, 0 ⁇ l ⁇ O 1 N 1 .
  • l may be at least one of ⁇ 0, 2 ⁇ .
  • l may be at least one of ⁇ 0, 1, 2, 3 ⁇ .
  • l may be 0 or 1.
  • the value of p 1 may be at least one of ⁇ 0, 1, 2, 3 ⁇ or ⁇ 0, 1 ⁇ or ⁇ 0, 2 ⁇ . In some embodiments, the value of p 1 may be 0. In some embodiments, the value of n 0 may be at least one of ⁇ 0, 1, 2, 3 ⁇ or ⁇ 0, 1 ⁇ or ⁇ 0, 2 ⁇ . In some embodiments, the value of n 0 may be 0. In some embodiments, the value of n 1 may be at least one of ⁇ 0, 1, 2, 3 ⁇ or ⁇ 0, 1 ⁇ or ⁇ 0, 2 ⁇ . In some embodiments, the value of n 1 may be 0.
  • the value of “O 2 ” may be 1.
  • corresponding to the fourth subset, corresponding to the fourth subset, m and m′ may be 0.
  • corresponding to the fourth subset, l′ l+k 1 .
  • corresponding to the fourth subset, l may be a non-negative integer, 0 ⁇ l ⁇ O 1 N 1 .
  • l may be at least one of ⁇ 0, 1, 2, 3 ⁇ .
  • l may be 0 or 1.
  • l may be 0 or 2.
  • the number of precoding matrixes in the fourth subset corresponding to 3 layers may be 64 or 32 or 16 or 8 or 4 or 2.
  • k 2 may be 0.
  • m and m′ may be 0.
  • p may be [p 1 p 2 ] .
  • n may be [n 0 n 1 n 2 ] .
  • the terminal device 110 is indicated with the number of layers is indicated as 3, there may be a second set of precoding matrixes corresponding to 3 layers (e.g. a second set of partial coherent precoding matrixes) .
  • a second set of precoding matrixes corresponding to 3 layers.
  • the terminal device 110 has 8 antenna ports or if a PUSCH transmission of the terminal device 110 is associated with 8 antenna ports or if a PUSCH transmission of the terminal device 110 is associated with SRS with 8 ports, 4 antenna ports (e.g. a first set of 4 ports) may be coherent and the other 4 antenna ports (e.g. a second set of 4 ports) may be coherent.
  • the first set of 4 ports may not be coherent with the second set of 4 ports.
  • a second set of precoding matrixes (e.g. a second set of partial coherent precoding matrixes) corresponding to 3 layers, for example, represented as “Set_p3_1”
  • the size of a partial coherent precoding matrix may be 3 multiplies 8 or 8 multiplies 3.
  • 4 elements out of 8 elements in the partial coherent matrix may be with non-zero value.
  • the other 4 elements in the partial coherent precoding matrix may be with value of 0.
  • C3 columns or rows out of the 3 columns or rows (e.g. a first set of C3 columns or rows.
  • C3 may be 1 or 2 or 3) in the precoding matrix, and in each column, the non-zero value may be mapped on 4 out of 8 elements and 0 for the other 4 elements.
  • the indexes of the 4 elements with non-zero values may be same in the first set of C3 columns or rows.
  • the indexes of the 4 elements with non-zero values may be idx_1, and idx_1 may be 4 values out of ⁇ 0, 1, 2, 3, 4, 5, 6, 7 ⁇ or ⁇ 1, 2, 3, 4, 5, 6, 7, 8 ⁇ .
  • the 4 values of idx_1 may be based on the indexes of the 4 antenna ports in the first group or the second group.
  • idx_1 may be ⁇ 0, 1, 2, 3 ⁇ or ⁇ 0, 2, 4, 6 ⁇ or ⁇ 1, 2, 3, 4 ⁇ or ⁇ 1, 3, 5, 7 ⁇ .
  • 3-C3 of the first set or second set of length-4 vectors may be selected.
  • 3-C3 columns or rows out of the 3 columns or rows e.g.
  • non-zero values may be mapped on 4 out of 8 elements and 0 may be mapped on the other 4 elements.
  • the indexes of the 4 elements with non-zero values may be same in the second set of 3-C3 columns or rows.
  • the indexes of the 4 elements with non-zero values may be idx_2, and idx_2 may be 4 values out of ⁇ 0, 1, 2, 3, 4, 5, 6, 7 ⁇ or ⁇ 1, 2, 3, 4, 5, 6, 7, 8 ⁇ .
  • the 4 values of idx_2 may be based on the indexes of the 4 antenna ports in the first group or the second group.
  • idx_2 may be ⁇ 4, 5, 6, 7 ⁇ or ⁇ 1, 3, 5, 7 ⁇ or ⁇ 5, 6, 7, 8 ⁇ or ⁇ 2, 4, 6, 8 ⁇ .
  • any value of idx_1 may be different from any value of idx_2.
  • C3 may be 3 and there may be no second set of columns or rows.
  • each set may include 4 length-4 vectors.
  • the values in a length-4 vector may be applied for the 4 non-zero values mapping on 4 elements in a column or row of the precoding matrix.
  • the first set of length-4 vectors may be ⁇ [1; 1; 1; 1] , [1; -1; 1; -1] , [1; 1; -1; -1] , [1; -1; -1; 1] ⁇ .
  • the second set of length-4 vectors may be ⁇ [1; 1; j; j] , [1; -1; j; -j] , [1; 1; -j; -j] , [1; -1; -j; j] ⁇ .
  • the 4 values in each vector of the first set or of the second set may be mapped on the 4 out of 8 elements, and 0 may be mapped on other 4 elements in a column or row of the precoding matrix.
  • examples of a precoding matrix of the second set of precoding matrixes corresponding to 3 layers may be as:
  • rows or columns can be swapped.
  • rows or columns can be swapped.
  • each of [a1, a2, a3, a4] , [b1, b2, b3, b4] , [c1, c2, c3, c4] may be one of the length-4 vectors in the first set of length-4 vectors or in the second set of length-4 vectors.
  • [a1, a2, a3, a4] , [b1, b2, b3, b4] , [c1, c2, c3, c4] may be three out of [1; 1; 1; 1] , [1; -1; 1; -1] , [1; 1; -1; -1] and [1; -1; -1; 1] .
  • [a1, a2, a3, a4] , [b1, b2, b3, b4] , [c1, c2, c3, c4] may be three out of [1; 1; j; j] , [1; -1; j; -j] , [1; 1; -j; -j] and [1; -1; -j; j] .
  • each of [a1, a2, a3, a4] , [b1, b2, b3, b4] , [c1, c2, c3, c4] may be one of the length-4 vectors in the first set of length-4 vectors or in the second set of length-4 vectors.
  • [a1, a2, a3, a4] , [b1, b2, b3, b4] may be two vectors out of [1; 1; 1; 1] , [1; -1; 1; -1] , [1; 1; -1; -1] and [1; -1; -1; 1] .
  • [a1, a2, a3, a4] , [b1, b2, b3, b4] may be two of [1; 1; j; j] , [1; -1; j; -j] , [1; 1; -j; -j] and [1; -1; -j; j] .
  • [c1, c2, c3, c4] may be 1 vector out of [1; 1; 1; 1] , [1; -1; 1; -1] , [1; 1; -1; -1] and [1; -1; -1; 1] .
  • [c1, c2, c3, c4] may be 1 vector out of [1; 1; j; j] , [1; -1; j; -j] , [1; 1; -j; -j] and [1; -1; -j; j] .
  • s 3 may a positive integer. For example, 1 ⁇ s 3 ⁇ 64.
  • s 3 may be 64 or 32 or 16 or 8 or 4 or 2 or 24 or 12 or 6 or 3.
  • the terminal device 110 is indicated with the number of layers is indicated as 3, there may be a third set of precoding matrixes (e.g. a third set of partial coherent precoding matrixes) corresponding to 3 layers.
  • the structure of the 8 ports may be 2+2+2+2, which means that there are 4 groups, each group including 2 antenna ports and in each group, 2 antenna ports can be coherent. For example, between the groups, the antenna ports may not be coherent.
  • there may be a third set of precoding matrixes e.g.
  • a third set of partial coherent precoding matrixes for example, represented as “Set_p3_2”
  • the size of a precoding matrix may be 3 multiplies 8 or 8 multiplies 3.
  • 2 elements out of 8 elements in the precoding matrix may be with non-zero value.
  • the other 6 elements in the precoding matrix may be with value of 0.
  • there may be 1 or 2 columns or rows out of the 3 columns or rows e.g.
  • non-zero values may be mapped on 2 out of 8 elements and 0 may be mapped on the other 6 elements.
  • the indexes of the 2 elements with non-zero values may be same in the first set of 1 or 2 columns or rows.
  • the indexes of the 2 elements with non-zero values may be idx_1, and idx_1 may be 2 values out of ⁇ 0, 1, 2, 3, 4, 5, 6, 7 ⁇ or ⁇ 1, 2, 3, 4, 5, 6, 7, 8 ⁇ .
  • the 2 values of idx_1 may be based on the indexes of two out of the 4 antenna ports in the first group.
  • the 2 values of idx_1 may be based on the indexes of the 2 antenna ports in the third group or fourth group or fifth group or sixth group.
  • idx_1 may be ⁇ 0, 1 ⁇ or ⁇ 0, 2 ⁇ or ⁇ 1, 2 ⁇ or ⁇ 1, 3 ⁇ or ⁇ 0, 4 ⁇ or ⁇ 1, 5 ⁇ .
  • the indexes of the 2 elements with non-zero values may be same in the second set of 1 or 2 columns or rows.
  • the indexes of the 2 elements with non-zero values may be idx_2, and idx_2 may be 2 values out of ⁇ 0, 1, 2, 3, 4, 5, 6, 7 ⁇ or ⁇ 1, 2, 3, 4, 5, 6, 7, 8 ⁇ .
  • the 2 values of idx_2 may be based on the indexes of two out of the 4 antenna ports in the first group or second group.
  • the 2 values of idx_2 may be based on the indexes of the 2 antenna ports in the third group or fourth group or fifth group or sixth group.
  • idx_2 may be ⁇ 2, 3 ⁇ or ⁇ 1, 3 ⁇ or ⁇ 3, 4 ⁇ or ⁇ 2, 4 ⁇ or ⁇ 1, 5 ⁇ or ⁇ 2, 6 ⁇ .
  • the indexes of the 2 elements with non-zero values may be same in the third set of 1 or 2 columns or rows.
  • the indexes of the 2 elements with non-zero values may be idx_3, and idx_3 may be 2 values out of ⁇ 0, 1, 2, 3, 4, 5, 6, 7 ⁇ or ⁇ 1, 2, 3, 4, 5, 6, 7, 8 ⁇ .
  • idx_3 may be ⁇ 4, 5 ⁇ or ⁇ 4, 6 ⁇ or ⁇ 5, 6 ⁇ or ⁇ 5, 7 ⁇ or ⁇ 2, 6 ⁇ or ⁇ 3, 7 ⁇ .
  • the 2 values of idx_3 may be based on the indexes of two out of the 4 antenna ports in the first group or second group.
  • the 2 values of idx_3 may be based on the indexes of the 2 antenna ports in the third group or fourth group or fifth group or sixth group.
  • the indexes of the 2 elements with non-zero values may be same in the fourth set of 1 or 2 columns or rows.
  • the indexes of the 2 elements with non-zero values may be idx_4, and idx_4 may be 2 values out of ⁇ 0, 1, 2, 3, 4, 5, 6, 7 ⁇ or ⁇ 1, 2, 3, 4, 5, 6, 7, 8 ⁇ .
  • the 2 values of idx_4 may be based on the indexes of remaining two out of the 4 antenna ports in the first group or second group.
  • the 2 values of idx_4 may be based on the indexes of the 2 antenna ports in the third group or fourth group or fifth group or sixth group.
  • idx_4 may be ⁇ 6, 7 ⁇ or ⁇ 5, 7 ⁇ or ⁇ 7, 8 ⁇ or ⁇ 6, 8 ⁇ or ⁇ 3, 7 ⁇ or ⁇ 4, 8 ⁇ .
  • 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.
  • the total number of columns or rows in the first set and/or the second set and/or the third set and/or the fourth set may be 3.
  • each one of the length-2 vector may be applied as the two non-zero values in a column or row of the precoding matrix.
  • two length-2 vectors can be selected from the 4 length-2 vectors, and the 2 values in each vector may be mapped on 2 out of 8 elements, and 0 may be mapped on other elements in a column or row of the precoding matrix.
  • the two values in a length-2 vector may be applied as the two non-zero values mapping on 2 elements in a column or row of the precoding matrix.
  • the first set of the length-2 vectors may be ⁇ [1; 1] , [1; -1] ⁇ .
  • the second set of the length-2 vectors may be ⁇ [1; j] , [1; -j] ⁇ .
  • the 2 values in each vector of the first set or of the second set may be mapped on 2 out of 8 elements, and 0 may be mapped on other 6 elements in a column or row of the precoding matrix.
  • the two vectors selected for mapping to 2 non-zero values on 2 elements out of 8 elements in each column or row may be ⁇ [1; 1] and [1; -1] ⁇ or ⁇ [1; j] and [1; -j] ⁇ .
  • examples of a precoding matrix of the third set of precoding matrixes corresponding to 3 layers may be as:
  • each of [a1, a2] , [b1, b2] , [c1, c2] may be one of the length-2 vectors in the first set of length-2 vectors or in the second set of length-2 vectors.
  • [a1, a2] , [b1, b2] may be [1; 1] , [1; -1] , respectively.
  • [a1, a2] , [b1, b2] may be [1; j] , [1; -j] , respectively.
  • [a1, a2] , [b1, b2] , [c1, c2] may be any one of [1; 1] , [1; -1] , [1; j] , [1; -j] .
  • the terminal device 110 is indicated with the number of layers is indicated as 3, there may be a fourth set of precoding matrixes (e.g. a fourth set of non-coherent precoding matrixes) corresponding to 3 layers.
  • a fourth set of precoding matrixes e.g. a fourth set of non-coherent precoding matrixes
  • the size of a precoding matrix may be 3 multiplies 8 or 8 multiplies 3.
  • 1 elements out of 8 elements in the precoding matrix may be with non-zero value.
  • the non-zero value may be 1.
  • the other 7 elements in the precoding matrix may be with value of 0.
  • the non-zero value may be mapped on 1 out of 8 elements and 0 may be mapped on the other 7 elements.
  • the indexes of the element with non-zero value may be different in each row or column of the precoding matrix.
  • the index of the 1 element with non-zero value may be idx_1, idx_2, idx_3 for the first, second, third column or row of the precoding matrix, respectively, and for each one of idx_1, idx_2, idx_3, 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 ⁇ .
  • the values of idx_1, idx_2 and idx_3 may be based on the indexes of three out of the 4 antenna ports in the first group or second group.
  • the values of idx_1, idx_2 and idx_3 may be based on the indexes of the 2 antenna ports in the third group or fourth group or fifth group or sixth group and based on an index of one out of 2 antenna ports in the third group or fourth group or fifth group.
  • the value of idx_1, idx_2, idx_3 may be one value out of ⁇ 0, 1, 2, 3 ⁇ or ⁇ 0, 2, 4, 6 ⁇ or ⁇ 4, 5, 6, 7 ⁇ or ⁇ 1, 3, 5, 7 ⁇ , respectively.
  • the value of idx_1, idx_2, idx_3 may be one value out of ⁇ 1, 2, 3, 4 ⁇ or ⁇ 5, 6, 7, 8 ⁇ or ⁇ 1, 3, 5, 7 ⁇ or ⁇ 2, 4, 6, 8 ⁇ , respectively.
  • the value of idx_1, idx_2, idx_3 may be different from each other.
  • the terminal device 110 is indicated with number of layers as 3 there may be a fourth set of precoding matrixes corresponding to 3 layers.
  • a precoding matrix in the fourth set of precoding matrixes corresponding to 3 layers may be
  • the terminal device 110 is indicated with the number of layers as 2, there may be a first set of precoding matrixes corresponding to 2 layers (e.g. a first set of full coherent precoding matrixes) .
  • a full coherent precoding matrix may be represented as
  • P may be 8 or 12 or 16.
  • l may be a non-negative integer. For example, 0 ⁇ l ⁇ O 1 N 1 . For another example, 0 ⁇ l ⁇ O 1 N 1 /2.
  • l may be at least one of ⁇ 0, 2, 4, 6 ⁇ .
  • l may be at least one of ⁇ 0, 1, 2, 3 ⁇ .
  • l may be 0 or 1.
  • m may be a non-negative integer.
  • m may be at least one of ⁇ 0, 2, 4, 6 ⁇ .
  • m may be at least one of ⁇ 0, 1, 2, 3 ⁇ .
  • n may be 0 or 1.
  • n may be 0.
  • n may be a non-negative integer.
  • n may be at least one of ⁇ 0, 1, 2, 3 ⁇ .
  • n may be 0 or 1.
  • n may be 0 or 2.
  • n may be 0.
  • l′ l+k 1 .
  • m′ m+k 2 .
  • k 1 may be a non-negative integer.
  • k 1 may at least one of ⁇ 0, O 1 , 2O 1 , 3O 1 ⁇ .
  • k 1 may be 0.
  • k 2 may be a non-negative integer.
  • k 2 may at least one of ⁇ 0, O 2 ⁇ .
  • k 2 may be 0.
  • i 1, 3 there may be a parameter i 1, 3 , and the value of k 1 and/or k 2 may be based on the value of i 1, 3 , and i 1, 3 may be a non-negative integer.
  • i 1, 3 may be at least one of ⁇ 0, 1, 2, 3 ⁇ .
  • i 1, 3 may be 0 or 1.
  • i 1, 3 may be 0.
  • the first set of precoding matrixes corresponding to 2 layers may comprise more than one subset. For example, there may be two or three or four subsets of precoding matrixes.
  • the value of “O 2 ” may be 1.
  • corresponding to the first subset, corresponding to the first subset, m and m′ may be 0.
  • corresponding to the first subset, l′ l+k 1 .
  • corresponding to the first subset, l may be a non-negative integer, 0 ⁇ l ⁇ O 1 N 1 .
  • l may be at least one of ⁇ 0, 2, 4, 6 ⁇ .
  • l may be at least one of ⁇ 0, 1, 2, 3 ⁇ .
  • l may be 0 or 1.
  • l may be 0 or 2.
  • the number of precoding matrixes in the first subset corresponding to 2 layers may be 128 or 64 or 32 or 16 or 8 or 4 or 2.
  • the value of “O 2 ” may be 4 or 2 or 1.
  • l may be at least one of ⁇ 0, 2, 4, 6 ⁇ .
  • l may be at least one of ⁇ 0, 1, 2, 3 ⁇ .
  • l may be 0 or 1.
  • l may be 0 or 2.
  • m may be a non-negative integer. For example, 0 ⁇ m ⁇ O 2 N 2 .
  • m may be at least one of ⁇ 0, 2, 4, 6 ⁇ .
  • m may be at least one of ⁇ 0, 1, 2, 3 ⁇ .
  • m may be 0 or 1.
  • m may be 0.
  • the number of precoding matrixes in the second subset corresponding to 2 layers may be 256 or 128 or 32 or 16 or 8 or 4 or 2.
  • l may be a non-negative integer. For example, 0 ⁇ l ⁇ O 1 N 1 .
  • l may be at least one of ⁇ 0, 2 ⁇ .
  • l may be at least one of ⁇ 0, 1, 2, 3 ⁇ .
  • l may be 0 or 1.
  • the value of p 1 may be at least one of ⁇ 0, 1, 2, 3 ⁇ or ⁇ 0, 1 ⁇ or ⁇ 0, 2 ⁇ . In some embodiments, the value of p 1 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.
  • i 1, 3 there may be a parameter i 1, 3 , and the value of k 1 and/or k 2 may be based on the value of i 1, 3 , and i 1, 3 may be a non-negative integer.
  • i 1, 3 may be at least one of ⁇ 0, 1 ⁇ .
  • i 1, 3 may be 0.
  • the value of “O 2 ” may be 1.
  • corresponding to the third subset In some embodiments, corresponding to the third subset, m and m′ may be 0.
  • corresponding to the third subset, l′ l+k 1 .
  • corresponding to the third subset, l may be a non-negative integer, 0 ⁇ l ⁇ O 1 N 1 .
  • l may be at least one of ⁇ 0, 1, 2, 3 ⁇ .
  • l may be 0 or 1.
  • l may be 0 or 2.
  • the number of precoding matrixes in the third subset corresponding to 2 layers may be 64 or 32 or 16 or 8 or 4 or 2.
  • l may be a non-negative integer. For example, 0 ⁇ l ⁇ O 1 N 1 .
  • l may be at least one of ⁇ 0, 2 ⁇ .
  • l may be at least one of ⁇ 0, 1, 2, 3 ⁇ .
  • l may be 0 or 1.
  • the value of p 1 may be at least one of ⁇ 0, 1, 2, 3 ⁇ or ⁇ 0, 1 ⁇ or ⁇ 0, 2 ⁇ . In some embodiments, the value of p 1 may be 0. In some embodiments, the value of n 0 may be at least one of ⁇ 0, 1, 2, 3 ⁇ or ⁇ 0, 1 ⁇ or ⁇ 0, 2 ⁇ . In some embodiments, the value of n 0 may be 0. In some embodiments, the value of n 1 may be at least one of ⁇ 0, 1, 2, 3 ⁇ or ⁇ 0, 1 ⁇ or ⁇ 0,2 ⁇ . In some embodiments, the value of n 1 may be 0.
  • the value of “O 2 ” may be 1.
  • corresponding to the fourth subset, corresponding to the fourth subset, m and m′ may be 0.
  • corresponding to the fourth subset, l′ l+k 1 .
  • corresponding to the fourth subset, l may be a non-negative integer, 0 ⁇ l ⁇ O 1 N 1 .
  • l may be at least one of ⁇ 0, 1, 2, 3 ⁇ .
  • l may be 0 or 1.
  • l may be 0 or 2.
  • the number of precoding matrixes in the fourth subset corresponding to 2 layers may be 64 or 32 or 16 or 8 or 4 or 2.
  • k 2 may be 0.
  • m and m′ may be 0.
  • p may be [p 1 p 2 ] .
  • n may be [n 0 n 1 n 2 ] .
  • the terminal device 110 is indicated with the number of layers is indicated as 2, there may be a second set of precoding matrixes corresponding to 2 layers (e.g. a second set of partial coherent precoding matrixes) .
  • a second set of precoding matrixes corresponding to 2 layers.
  • the terminal device 110 has 8 antenna ports or if a PUSCH transmission of the terminal device 110 is associated with 8 antenna ports or if a PUSCH transmission of the terminal device 110 is associated with SRS with 8 ports, 4 antenna ports (e.g. a first set of 4 ports) may be coherent and the other 4 antenna ports (e.g. a second set of 4 ports) may be coherent.
  • the first set of 4 ports may not be coherent with the second set of 4 ports.
  • a second set of precoding matrixes (e.g. a second set of partial coherent precoding matrixes) corresponding to 2 layers, for example, represented as “Set_p2_1”
  • the size of a partial coherent precoding matrix may be 2 multiplies 8 or 8 multiplies 2.
  • 4 elements out of 8 elements in the partial coherent matrix may be with non-zero value.
  • the other 4 elements in the partial coherent precoding matrix may be with value of 0.
  • C4 1 or 2) in the precoding matrix, and in each column, the non-zero value may be mapped on 4 out of 8 elements and 0 for the other 4 elements.
  • the indexes of the 4 elements with non-zero values may be same in the first set of C4 columns or rows.
  • the indexes of the 4 elements with non-zero values may be idx_1, and idx_1 may be 4 values out of ⁇ 0, 1, 2, 3, 4, 5, 6, 7 ⁇ or ⁇ 1, 2, 3, 4, 5, 6, 7, 8 ⁇ .
  • the 4 values of idx_1 may be based on the indexes of the 4 antenna ports in the first group or second group.
  • idx_1 may be ⁇ 0, 1, 2, 3 ⁇ or ⁇ 0, 2, 4, 6 ⁇ or ⁇ 1, 2, 3, 4 ⁇ or ⁇ 1, 3, 5, 7 ⁇ .
  • 2-C4 of the first set or second set of length-4 vectors may be selected.
  • 2-C4 columns or rows out of the 2 columns or rows e.g.
  • non-zero values may be mapped on 4 out of 8 elements and 0 may be mapped on the other 4 elements.
  • the indexes of the 4 elements with non-zero values may be same in the second set of 2-C4 columns or rows.
  • the indexes of the 4 elements with non-zero values may be idx_2, and idx_2 may be 4 values out of ⁇ 0, 1, 2, 3, 4, 5, 6, 7 ⁇ or ⁇ 1, 2, 3, 4, 5, 6, 7, 8 ⁇ .
  • the 4 values of idx_2 may be based on the indexes of the 4 antenna ports in the first group or second group.
  • idx_2 may be ⁇ 4, 5, 6, 7 ⁇ or ⁇ 1, 3, 5, 7 ⁇ or ⁇ 5, 6, 7, 8 ⁇ or ⁇ 2, 4, 6, 8 ⁇ .
  • any value of idx_1 may be different from any value of idx_2.
  • C4 may be 2 and there may be no second set of columns or rows.
  • each set may include 4 length-4 vectors.
  • the values in a length-4 vector may be applied for the 4 non-zero values mapping on 4 elements in a column or row of the precoding matrix.
  • the first set of length-4 vectors may be ⁇ [1; 1; 1; 1] , [1; -1; 1; -1] , [1; 1; -1; -1] , [1; -1; -1; 1] ⁇ .
  • the second set of length-4 vectors may be ⁇ [1; 1; j; j] , [1; -1; j; -j] , [1; 1; -j; -j] , [1; -1; -j; j] ⁇ .
  • the 4 values in each vector of the first set or of the second set may be mapped on the 4 out of 8 elements, and 0 may be mapped on other 4 elements in a column or row of the precoding matrix.
  • examples of a precoding matrix of the second set of precoding matrixes corresponding to 2 layers may be as:
  • each of [a1, a2, a3, a4] , [b1, b2, b3, b4] may be one of the length-4 vectors in the first set of length-4 vectors or in the second set of length-4 vectors.
  • [a1, a2, a3, a4] , [b1, b2, b3, b4] may be two out of [1; 1; 1; 1] , [1; -1; 1; -1] , [1; 1; -1; -1] and [1; -1; -1; 1] .
  • [a1, a2, a3, a4] , [b1, b2, b3, b4] may be two out of [1; 1; j; j] , [1; -1; j; -j] , [1; 1; -j; -j] and [1; -1; -j; j] .
  • each of [a1, a2, a3, a4] , [b1, b2, b3, b4] may be one of the length-4 vectors in the first set of length-4 vectors or in the second set of length-4 vectors.
  • s 2 may a positive integer. For example, 1 ⁇ s 2 ⁇ 64.
  • s 2 may be 64 or 32 or 16 or 8 or 4 or 2.
  • the terminal device 110 is indicated with the number of layers as 2, there may be a third set of precoding matrixes (e.g. a third set of partial coherent precoding matrixes) corresponding to 2 layers.
  • the structure of the 8 ports may be 2+2+2+2, which means that there are 4 groups, each group including 2 antenna ports and in each group, 2 antenna ports can be coherent. For example, between the groups, the antenna ports may not be coherent.
  • there may be a third set of precoding matrixes e.g. a third set of partial coherent precoding matrixes
  • the size of a precoding matrix may be 2 multiplies 8 or 8 multiplies 2.
  • the indexes of the 2 elements with non-zero values may be same in the first set of 1 or 2 columns or rows.
  • the indexes of the 2 elements with non-zero values may be idx_1, and idx_1 may be 1 or 2 values out of ⁇ 0, 1, 2, 3, 4, 5, 6, 7 ⁇ or ⁇ 1, 2, 3, 4, 5, 6, 7, 8 ⁇ .
  • the 2 values of idx_1 may be based on the indexes of two out of the 4 antenna ports in the first group or second group.
  • the 2 values of idx_1 may be based on the indexes of the 2 antenna ports in the third group or fourth group or fifth group or sixth group.
  • idx_1 may be ⁇ 0, 1 ⁇ or ⁇ 0, 2 ⁇ or ⁇ 1, 2 ⁇ or ⁇ 1, 3 ⁇ or ⁇ 0, 4 ⁇ or ⁇ 1, 5 ⁇ .
  • the indexes of the 2 elements with non-zero values may be same in the second set of 1 or 2 columns or rows.
  • the indexes of the 2 elements with non-zero values may be idx_2, and idx_2 may be 1 or 2 values out of ⁇ 0, 1, 2, 3, 4, 5, 6, 7 ⁇ or ⁇ 1, 2, 3, 4, 5, 6, 7, 8 ⁇ .
  • the 2 values of idx_2 may be based on the indexes of remaining two out of the 4 antenna ports in the first group or second group.
  • the 2 values of idx_2 may be based on the indexes of the 2 antenna ports in the third group or fourth group or fifth group or sixth group.
  • idx_2 may be ⁇ 2, 3 ⁇ or ⁇ 1, 3 ⁇ or ⁇ 3, 4 ⁇ or ⁇ 2, 4 ⁇ or ⁇ 1, 5 ⁇ or ⁇ 2, 6 ⁇ .
  • any value of idx_1 and any value of idx_2 may be different from each other.
  • the total number of columns or rows in the first set and/or the second set may be 2.
  • each one of the length-2 vector may be applied as the two non-zero values in a column or row of the precoding matrix.
  • two length-2 vectors can be selected from the 4 length-2 vectors, and the 2 values in each vector may be mapped on 2 out of 8 elements, and 0 may be mapped on other elements in a column or row of the precoding matrix.
  • the two values in a length-2 vector may be applied as the two non-zero values mapping on 2 elements in a column or row of the precoding matrix.
  • the first set of the length-2 vectors may be ⁇ [1; 1] , [1; -1] ⁇ .
  • the second set of the length-2 vectors may be ⁇ [1; j] , [1; -j] ⁇ .
  • the 2 values in each vector of the first set or of the second set may be mapped on 2 out of 8 elements, and 0 may be mapped on other 6 elements in a column or row of the precoding matrix.
  • the two vectors selected for mapping to 2 non-zero values on 2 elements out of 8 elements in each column or row may be ⁇ [1; 1] and [1; -1] ⁇ or ⁇ [1; j] and [1; -j] ⁇ .
  • examples of a precoding matrix of the third set of precoding matrixes corresponding to 2 layers may be as:
  • each of [a1, a2] , [b1, b2] may be one of the length-2 vectors in the first set of length-2 vectors or in the second set of length-2 vectors.
  • [a1, a2] , [b1, b2] may be [1; 1] , [1; -1] , respectively.
  • [a1, a2] , [b1, b2] may be [1; j] , [1; -j] , respectively.
  • [a1, a2] , [b1, b2] may be any one of [1; 1] , [1; -1] , [1; j] , [1; -j] .
  • the terminal device 110 is indicated with the number of layers is indicated as 2, there may be a fourth set of precoding matrixes (e.g. a fourth set of non-coherent precoding matrixes) corresponding to 2 layers.
  • each one of 8 antenna ports may be non-coherent with each other.
  • there may be a fourth set of precoding matrixes e.g. a fourth set of non-coherent precoding matrixes
  • the size of a precoding matrix may be 2 multiplies 8 or 8 multiplies 2.
  • 1 elements out of 8 elements in the precoding matrix may be with non-zero value.
  • the non-zero value may be 1.
  • the other 7 elements in the precoding matrix may be with value of 0.
  • the non-zero value may be mapped on 1 out of 8 elements and 0 may be mapped on the other 7 elements.
  • the indexes of the element with non-zero value may be different in each row or column of the precoding matrix.
  • the index of the 1 element with non-zero value may be idx_1, idx_2 for the first, second column or row of the precoding matrix, respectively, and for each one of idx_1, idx_2, 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 ⁇ .
  • the values of idx_1 and idx_2 may be based on the indexes of two out of the 4 antenna ports in the first group or second group.
  • the values of idx_1 and idx_2 may be based on the indexes of the 2 antenna ports in the third group or fourth group or fifth group or sixth group.
  • the value of idx_1, idx_2 may be one value of ⁇ 0, 1, 2, 3 ⁇ or ⁇ 0, 2, 4, 6 ⁇ or ⁇ 4, 5, 6, 7 ⁇ or ⁇ 1, 3, 5, 7 ⁇ , respectively.
  • the value of idx_1, idx_2 may be ⁇ 1, 2 ⁇ ⁇ 3, 4 ⁇ or ⁇ 5, 6 ⁇ , ⁇ 7, 8 ⁇ or ⁇ 1, 3 ⁇ , ⁇ 5, 7 ⁇ or ⁇ 2, 4 ⁇ , ⁇ 6, 8 ⁇ .
  • the value of idx_1, idx_2 may be different from each other.
  • the terminal device 110 is indicated with number of layers as 2, there may be a fourth set of precoding matrixes corresponding to 2 layers.
  • a precoding matrix in the fourth set of precoding matrixes corresponding to 2 layers may be
  • the terminal device 110 is indicated with the number of layers as 1, there may be a first set of precoding matrixes corresponding to 1 layer (e.g. a first set of full coherent precoding matrixes) .
  • a full coherent precoding matrix may be represented as
  • P may be 8 or 12 or 16.
  • l may be a non-negative integer. For example, 0 ⁇ l ⁇ O 1 N 1 . For another example, 0 ⁇ l ⁇ O 1 N 1 /2.
  • l may be at least one of ⁇ 0, 2, 4, 6 ⁇ .
  • l may be at least one of ⁇ 0, 1, 2, 3 ⁇ .
  • l may be 0 or 1.
  • m may be a non-negative integer.
  • m may be at least one of ⁇ 0, 2, 4, 6 ⁇ .
  • m may be at least one of ⁇ 0, 1, 2, 3 ⁇ .
  • n may be 0 or 1.
  • n may be 0.
  • n may be a non-negative integer.
  • n may be at least one of ⁇ 0, 1, 2, 3 ⁇ .
  • n may be 0 or 1.
  • n may be 0 or 2.
  • n may be 0.
  • the first set of precoding matrixes corresponding to 1 layer may comprise more than one subset. For example, there may be two or three or four subsets of precoding matrixes.
  • corresponding to the first subset, corresponding to the first subset, m and m′ may be 0.
  • corresponding to the first subset, l′ l+k 1 .
  • corresponding to the first subset, l may be a non-negative integer, 0 ⁇ l ⁇ O 1 N 1 .
  • l may be at least one of ⁇ 0, 2, 4, 6 ⁇ .
  • l may be at least one of ⁇ 0, 1, 2, 3 ⁇ .
  • l may be 0 or 1.
  • l may be 0 or 2.
  • the number of precoding matrixes in the first subset corresponding to 1 layer may be 32 or 16 or 8 or 4 or 2.
  • the value of “O 2 ” may be 4 or 2 or 1.
  • corresponding to the second subset In some embodiments, corresponding to the second subset, l may be a non-negative integer, 0 ⁇ l ⁇ O 1 N 1 .
  • l may be at least one of ⁇ 0, 2, 4, 6 ⁇ .
  • l may be at least one of ⁇ 0, 1, 2, 3 ⁇ .
  • l may be 0 or 1.
  • l may be 0 or 2.
  • m may be a non-negative integer. For example, 0 ⁇ m ⁇ O 2 N 2 .
  • m may be at least one of ⁇ 0, 2, 4, 6 ⁇ .
  • m may be at least one of ⁇ 0, 1, 2, 3 ⁇ .
  • m may be 0 or 1.
  • m may be 0.
  • the number of precoding matrixes in the second subset corresponding to 1 layer may be 256 or 128 or 32 or 16 or 8 or 4 or 2.
  • l may be a non-negative integer. For example, 0 ⁇ l ⁇ O 1 N 1 .
  • l may be at least one of ⁇ 0, 2 ⁇ .
  • l may be at least one of ⁇ 0, 1, 2, 3 ⁇ .
  • l may be 0 or 1.
  • the value of p 1 may be at least one of ⁇ 0, 1, 2, 3 ⁇ or ⁇ 0, 1 ⁇ or ⁇ 0, 2 ⁇ . In some embodiments, the value of p 1 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.
  • the value of “O 2 ” may be 1.
  • corresponding to the third subset In some embodiments, corresponding to the third subset, l may be a non-negative integer, 0 ⁇ l ⁇ O 1 N 1 . 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.
  • the number of precoding matrixes in the third subset corresponding to 1 layer may be 256 or 128 or 64 or 32 or 16 or 8 or 4 or 2.
  • the terminal device 110 may be indicated with the number of layers as 1, a precoding matrix in the third subset of precoding matrixes corresponding to 1 layer may be represented as In some embodiments, may be In some embodiments, p may be p 1 .
  • l may be a non-negative integer. For example, 0 ⁇ l ⁇ O 1 N 1 .
  • l may be at least one of ⁇ 0, 2 ⁇ .
  • l may be at least one of ⁇ 0, 1, 2, 3 ⁇ .
  • l may be 0 or 1.
  • the value of p 1 may be at least one of ⁇ 0, 1, 2, 3 ⁇ or ⁇ 0, 1 ⁇ or ⁇ 0, 2 ⁇ . In some embodiments, the value of p 1 may be 0. In some embodiments, the value of n 0 may be at least one of ⁇ 0, 1, 2, 3 ⁇ or ⁇ 0, 1 ⁇ or ⁇ 0, 2 ⁇ . In some embodiments, the value of n 0 may be 0. In some embodiments, the value of n 1 may be at least one of ⁇ 0, 1, 2, 3 ⁇ or ⁇ 0, 1 ⁇ or ⁇ 0, 2 ⁇ . In some embodiments, the value of n 1 may be 0. In some embodiments, the value of n 2 may be at least one of ⁇ 0, 1, 2, 3 ⁇ or ⁇ 0, 1 ⁇ or ⁇ 0, 2 ⁇ . In some embodiments, the value of n 2 may be 0.
  • the value of “O 2 ” may be 1.
  • corresponding to the fourth subset In some embodiments, corresponding to the fourth subset, l may be a non-negative integer, 0 ⁇ l ⁇ O 1 N 1 . 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.
  • the number of precoding matrixes in the fourth subset corresponding to 1 layer may be 256 or 128 or 64 or 32 or 16 or 8 or 4 or 2.
  • the terminal device 110 may be indicated with the number of layers as 1, a precoding matrix in the fourth subset of precoding matrixes corresponding to 1 layer may be represented as In some embodiments, may be In some embodiments, p may be [p 1 p 2 ] . In some embodiments, n may be [n 0 n 1 n 2 ] .
  • the terminal device 110 if the terminal device 110 is indicated with the number of layers is indicated as 1, there may be a second set of precoding matrixes corresponding to 1 layers (e.g. a second set of partial coherent precoding matrixes) .
  • a second set of precoding matrixes corresponding to 1 layers.
  • the terminal device 110 has 8 antenna ports or if a PUSCH transmission of the terminal device 110 is associated with 8 antenna ports or if a PUSCH transmission of the terminal device 110 is associated with SRS with 8 ports, 4 antenna ports (e.g. a first set of 4 ports) may be coherent and the other 4 antenna ports (e.g. a second set of 4 ports) may be coherent.
  • the first set of 4 ports may not be coherent with the second set of 4 ports.
  • a second set of precoding matrixes corresponding to 2 layers, for example, represented as “Set_p1_1”
  • the size of a partial coherent precoding matrix may be 1 multiplies 8 or 8 multiplies 1.
  • 4 elements out of 8 elements in the partial coherent matrix may be with non-zero value.
  • the other 4 elements in the partial coherent precoding matrix may be with value of 0.
  • the non-zero value in the precoding matrix, and in the column or row, the non-zero value may be mapped on 4 out of 8 elements and 0 for the other 4 elements.
  • the indexes of the 4 elements with non-zero values idx_1, and idx_1 may be 4 values out of ⁇ 0, 1, 2, 3, 4, 5, 6, 7 ⁇ or ⁇ 1, 2, 3, 4, 5, 6, 7, 8 ⁇ .
  • the 4 values of idx_1 may be based on the indexes of the 4 antenna ports in the first group or second group.
  • 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 ⁇ .
  • each set may include 4 length-4 vectors.
  • the values in a length-4 vector may be applied for the 4 non-zero values mapping on 4 elements in a column or row of the precoding matrix.
  • the first set of length-4 vectors may be ⁇ [1; 1; 1; 1] , [1; -1; 1; -1] , [1; 1; -1; -1] , [1; -1; -1; 1] ⁇ .
  • the second set of length-4 vectors may be ⁇ [1; 1; j; j] , [1; -1; j; -j] , [1; 1; -j; -j] , [1; -1; -j; j] ⁇ .
  • the 4 values in each vector of the first set or of the second set may be mapped on the 4 out of 8 elements, and 0 may be mapped on other 4 elements in the column or row of the precoding matrix.
  • examples of a precoding matrix of the second set of precoding matrixes corresponding to 1 layer1 may be as:
  • rows or columns can be swapped.
  • rows or columns can be swapped.
  • each of [a1, a2, a3, a4] may be one of the length-4 vectors in the first set of length-4 vectors or in the second set of length-4 vectors.
  • [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] .
  • s 1 may a positive integer. For example, 1 ⁇ s 1 ⁇ 64.
  • s 1 may be 64 or 32 or 16 or 8 or 4 or 2 or 1.
  • the terminal device 110 if the terminal device 110 is indicated with the number of layers as 1, there may be a third set of precoding matrixes (e.g. a third set of partial coherent precoding matrixes) corresponding to 1 layer.
  • the structure of the 8 ports may be 2+2+2+2, which means that there are 4 groups, each group including 2 antenna ports and in each group, 2 antenna ports can be coherent. For example, between the groups, the antenna ports may not be coherent.
  • there may be a third set of precoding matrixes e.g. a third set of partial coherent precoding matrixes
  • the size of a precoding matrix may be 1 multiplies 8 or 8 multiplies 1.
  • the indexes of the 2 elements with non-zero values may be idx_1, and idx_1 may be 2 values out of ⁇ 0, 1, 2, 3, 4, 5, 6, 7 ⁇ or ⁇ 1, 2, 3, 4, 5, 6, 7, 8 ⁇ .
  • the 2 values of idx_1 may be based on the indexes of two out of the 4 antenna ports in the first group or second group.
  • the 2 values of idx_1 may be based on the indexes of the 2 antenna ports in the third group or fourth group or fifth group or sixth group.
  • each one of the length-2 vector may be applied as the two non-zero values in a column or row of the precoding matrix.
  • two length-2 vectors can be selected from the 4 length-2 vectors, and the 2 values in each vector may be mapped on 2 out of 8 elements, and 0 may be mapped on other elements in the column or row of the precoding matrix.
  • the two values in a length-2 vector may be applied as the two non-zero values mapping on 2 elements in a column or row of the precoding matrix.
  • the first set of the length-2 vectors may be ⁇ [1; 1] , [1; -1] ⁇ .
  • the second set of the length-2 vectors may be ⁇ [1; j] , [1; -j] ⁇ .
  • the 2 values in each vector of the first set or of the second set may be mapped on 2 out of 8 elements, and 0 may be mapped on other 6 elements in the column or row of the precoding matrix.
  • the two vectors selected for mapping to 2 non-zero values on 2 elements out of 8 elements in each column or row may be ⁇ [1; 1] and [1; -1] ⁇ or ⁇ [1; j] and [1; -j] ⁇ .
  • examples of a precoding matrix of the third set of precoding matrixes corresponding to 1 layer may be as:
  • rows or columns can be swapped.
  • [a1, a2] may be one of the length-2 vectors in the first set of length-2 vectors or in the second set of length-2 vectors.
  • [a1, a2] may be any one of [1; 1] , [1; -1] , [1; j] , [1; -j] .
  • the terminal device 110 is indicated with the number of layers is indicated as 1, there may be a fourth set of precoding matrixes (e.g. a fourth set of non-coherent precoding matrixes) corresponding to 1 layer.
  • a fourth set of precoding matrixes e.g. a fourth set of non-coherent precoding matrixes
  • the size of a precoding matrix may be 1 multiplies 8 or 8 multiplies 1.
  • 1 elements out of 8 elements in the precoding matrix may be with non-zero value.
  • the non-zero value may be 1.
  • the other 7 elements in the precoding matrix may be with value of 0.
  • the indexes of the element with non-zero value may be in the row or column of the precoding matrix may be idx_1, and idx_1 may be 1 value out of ⁇ 0, 1, 2, 3, 4, 5, 6, 7 ⁇ or ⁇ 1, 2, 3, 4, 5, 6, 7, 8 ⁇ .
  • the value of idx_1 may be based on the indexes of one out of the 4 antenna ports in the first group or second group. In some embodiments, the values of idx_1 may be based on the indexes of one of the 2 antenna ports in the third group or fourth group or fifth group or sixth group.
  • the terminal device 110 if the terminal device 110 is indicated with number of layers as 1, there may be a fourth set of precoding matrixes corresponding to 1 layer.
  • a precoding matrix in the fourth set of precoding matrixes corresponding to 1 layer may be
  • the terminal device 110 may transmit capability information to the network device 120.
  • the capability information may indicate a capability of precoding matrix supported by the terminal device 110.
  • the capability information may indicate a type of precoding matrix supported by the terminal device 110.
  • the capability information may comprise at least one of: a full coherent, a partial coherent, a first partial coherent, a second partial coherent, a non coherent.
  • the capability information may indicate the full coherent
  • the set of precoding matrix (for example, one of the set of precoding matrixes corresponding to v_ri layers can be indicated by the network device or one or more of the set of precoding matrixes can be configured by the network device) may comprise at least one of the first set (or at least one of the first subset, or at least one of the second subset or at least one of the third subset or at least one of fourth subset) of precoding matrixes corresponding to v_ri layers (e.g. a full-coherent precoding matrix type) .
  • the set of precoding matrix may further comprise at least one of the second set of precoding matrixes corresponding to v_ri layers (e.g.
  • the set of precoding matrixes may further comprise at least one of the third set of precoding matrixes corresponding to v_ri layers (e.g. a second partial-coherent precoding matrix type) .
  • the set of precoding matrixes may further comprise at least one of the fourth set of precoding matrixes corresponding to v_ri layers (e.g. a non-coherent precoding matrix type) .
  • the capability information may indicate the partial coherent or indicate the first partial coherent
  • the set of precoding matrix corresponding to v_ri layers may comprise at least one of the second set of precoding matrixes corresponding to v_ri layers (e.g. a first partial-coherent precoding matrix type) .
  • the set of precoding matrixes may further comprise at least one of the third set of precoding matrixes corresponding to v_ri layers (e.g. a second partial-coherent precoding matrix type) .
  • the set of precoding matrixes may further comprise at least one of the fourth set of precoding matrixes corresponding to v_ri layers (e.g. a non-coherent precoding matrix type) .
  • the capability information may indicate the second partial coherent
  • the set of precoding matrix corresponding to v_ri layers may comprise at least one of the third set of precoding matrixes corresponding to v_ri layers (e.g. a second partial-coherent precoding matrix type) .
  • the set of precoding matrixes may further comprise at least one of the fourth set of precoding matrixes corresponding to v_ri layers (e.g. a non-coherent precoding matrix type) .
  • the capability information may indicate the non coherent, the set of precoding matrix corresponding to v_ri layers (for example, one of the set of precoding matrixes can be indicated by the network device or one or more of the set of precoding matrixes can be configured by the network device) may comprise at least one of the fourth set of precoding matrixes corresponding to v_ri layers (e.g. a non-coherent precoding matrix type) .
  • the capability information may comprise any one or combination of the above precoding matrix types.
  • the capability information may be transmitted via radio resource control (RRC) signaling.
  • RRC radio resource control
  • the network device 120 may configure the type of precoding matrixes or at least one set of precoding matrixes corresponding to v_ri layers which can be indicated or configured to the terminal device 110.
  • the at least one configuration may configure at least one of the first subset of precoding matrixes corresponding to v_ri layers, the second subset of precoding matrixes corresponding to v_ri layers, the third subset of precoding matrixes corresponding to v_ri layers, the fourth subset of precoding matrixes corresponding to v_ri layers, the first set of precoding matrixes corresponding to v_ri layers, the second set of precoding matrixes corresponding to v_ri layers, the third set of precoding matrixes corresponding to v_ri layers and the fourth set of precoding matrixes corresponding to v_ri layers.
  • the at least one configuration may configure at least one of the first subset of precoding matrixes corresponding to v_ri layers, the second subset of precoding matrixes corresponding to v_ri layers, the third subset of precoding matrixes corresponding to v_ri layers, the fourth subset of precoding matrixes corresponding to v_ri layers, the first set of precoding matrixes corresponding to v_ri layers, the second set of precoding matrixes corresponding to v_ri layers, the third set of precoding matrixes corresponding to v_ri layers and the fourth set of precoding matrixes corresponding to v_ri layers.
  • the at least one configuration may configure at least one of the second set of precoding matrixes corresponding to v_ri layers, the third set of precoding matrixes corresponding to v_ri layers and the fourth set of precoding matrixes corresponding to v_ri layers.
  • the at least one configuration may configure at least one of the third set of precoding matrixes corresponding to v_ri layers and the fourth set of precoding matrixes corresponding to v_ri layers.
  • the at least one configuration may configure at least one of the fourth set of precoding matrixes corresponding to v_ri layers.
  • the network device 120 may determine the type of precoding matrix which can be supported by the terminal device. In this case, the network device 120 may transmit an indication of the type of the precoding matrix.
  • the type of the precoding matrix may be any one or combination of: a full-coherent precoding matrix type, a full-coherent and partial-coherent and non-coherent precoding matrix type, a partial-coherent precoding matrix type, a partial-coherent and a non-coherent precoding matrix type or a non-coherent precoding matrix type.
  • the network device 120 may transmit at least one configuration associated with precoding matrix to the terminal device 110.
  • the terminal device 110 may transmit the at least one configuration associated with precoding matrix to the network device 120.
  • the at least one configuration may comprise one or more configurations of antenna port groups. Alternatively or in addition, the at least one configuration may comprise at least one antenna port group. In other embodiments, the at least one configuration may comprise one or more configurations of antenna pattern. In some other embodiments, the at least one configuration may comprise one or more configurations of precoding matrix type. Alternatively or in addition, the at least one configuration may comprise one or more configurations of precoding matrix subsets. In some embodiments, the at least one configuration may comprise the number of antenna port groups. In other embodiments, the at least one configuration may comprise the number of antenna ports in an antenna port group.
  • the at least one configuration may comprise a first number of antenna groups and each of the antenna groups may comprise 4 antenna ports.
  • the first number may be 0 or 1 or 2.
  • the first number may be a first integer which is not larger than 2.
  • the at least one configuration may comprise a second number of antenna groups and each of the antenna groups may comprise 2 antenna ports.
  • the second number may be 0 or 1 or 2 or 3 or 4.
  • the second number may be a second integer which is not larger than 4.
  • the at least one configuration may comprise a third number of antenna groups and each of the antenna groups may comprise 1 antenna port.
  • the third number may be a third integer which is not larger than 8.
  • the at least one configuration may comprise at least one of: a subset of full-coherent precoding matrixes, a subset of partial-coherent precoding matrixes, or a subset of non-coherent precoding matrixes.
  • the terminal device 110 may be configured with 8Tx for uplink or 8 ports SRS, (e.g. AP_0, AP_1, AP_2, AP_3, AP_4, AP_5, AP_6, AP_7) .
  • SRS e.g. AP_0, AP_1, AP_2, AP_3, AP_4, AP_5, AP_6, AP_7 .
  • the at least one configuration may indicate a subset of full-coherent and/or partial-coherent and/or a first partial-coherent (e.g. partial-coherent4) and/or a second partial-coherent (e.g. partial-coherent2) and/or non-coherent precoding matrix.
  • the at least one configuration may be configured per value of number of layers or per precoder type.
  • N1, M1 may be configured for the first set of precoding matrixes corresponding to v_ri layers or for the full coherent precoding matrixes
  • N2, M2 may be configured for the second or the third set of precoding matrixes corresponding to v_ri layers or for the partial coherent precoding matrixes
  • N3, M3 may be configured for the fourth set of precoding matrixes corresponding to v_ri layers or for the non-coherent precoding matrixes.
  • the 8 antenna ports for PUSCH transmission or the 8 antenna ports of the 8-port SRS may be ⁇ AP0, AP1, AP2, AP3, AP4, AP5, AP6, AP7 ⁇ .
  • AP0 or AP1 or AP2 or AP3 or AP4 or AP5 or AP6 or AP7 may be any one of ⁇ 0, 1, 2 , 3, 4, 5, 6, 7 ⁇ or any one of ⁇ 1000, 1001, 1002, 1003, 1004, 1005, 1006, 1007 ⁇ or any one of ⁇ 3000, 3001, 3002, 3003, 3004, 3005, 3006, 3007 ⁇ .
  • the values of AP0 or AP1 or AP2 or AP3 or AP4 or AP5 or AP6 or AP7 may be different from each other.
  • each group 1 or 2 or 4 of ⁇ AP_a, AP_b, AP_c, AP_d, AP_e, AP_f, AP_g, AP_h ⁇ can be included.
  • the ⁇ a, b, c, d, e, f, g, h ⁇ , ⁇ AP_a, AP_b, AP_c, AP_d, AP_e, AP_f, AP_g, AP_h ⁇ may integer and can be ⁇ 0, 1, 2, 3, 4, 5, 6, 7 ⁇ . The numbers may be different from each other.
  • port grouping configurations (4 ports in a group) , ⁇ 0, 1, 2, 3 ⁇ , ⁇ 4, 5, 6, 7 ⁇ or ⁇ 0, 2, 4, 6 ⁇ , ⁇ 1, 3, 5, 7 ⁇ .
  • port grouping configurations (2 ports in a group) , ⁇ 0, 1 ⁇ , ⁇ 2, 3 ⁇ , ⁇ 4, 5 ⁇ , ⁇ 6, 7 ⁇ or ⁇ 0, 2 ⁇ , ⁇ 1, 3 ⁇ , ⁇ 4, 6 ⁇ , ⁇ 5, 7 ⁇ .
  • the at least one configuration may indicate one of the port grouping configurations.
  • DMRS ports in same group may share a same PTRS port.
  • the terminal device 110 may be configured with 8Tx for uplink transmission or configured with PUSCH transmission associated with SRS with 8 ports.
  • the at least one configuration may include at least one of: values for i 1, 1 , values for i 1, 2 , values for i 1, 3 , values for i 2 , values for i 1, 4, 1 , values for i 1, 4, 2 , values for i 2, 0 , values for i 2, 1 , values for i 2, 2 , values for Ng, values for N 1 , values for N 2 , values for O 1 , values for O 2 , and a configuration pattern (e.g. for antenna ports) .
  • the configuration pattern and/or the values may be applied at least for full-coherent precoding matrixes.
  • the at least one configuration may indicate the first subset or the second subset or the third subset or the fourth subset of precoding matrixes corresponding to v_ri layers may be applied for the PUSCH transmission.
  • the DCI may indicate one of the applicable precoding matrixes for the PUSCH transmission.
  • the at least one configuration may indicate two groups of antenna ports, and each group may comprise 4 antenna ports, and based on the at least one configuration, a DCI may indicate one precoding matrix of the first subset of precoding matrixes corresponding to v_ri layers for the PUSCH transmission. In some embodiments, the at least one configuration may indicate four groups of antenna ports, and each group comprises 2 antenna ports, and based on the at least one configuration, a DCI may indicate one precoding matrix of the second subset of precoding matrixes corresponding to v_ri layers for the PUSCH transmission.
  • the at least one configuration may indicate four groups of antenna ports, and each group comprises 2 antenna ports, and based on the at least one configuration, a DCI may indicate one precoding matrix of the third subset of precoding matrixes corresponding to v_ri layers for the PUSCH transmission. In some embodiments, the at least one configuration may indicate four groups of antenna ports, and each group comprises 2 antenna ports, and based on the at least one configuration, a DCI may indicate one precoding matrix of the fourth subset of precoding matrixes corresponding to v_ri layers for the PUSCH transmission.
  • the at least one configuration may indicate one or two groups of antenna ports, and each group may comprise 4 antenna ports, and based on the at least one configuration, a DCI may indicate one precoding matrix from the second subset of precoding matrixes corresponding to v_ri layers for the PUSCH transmission.
  • the indexes of the 4 non-zero values may be based on the indexes of antenna port indexes in a group.
  • the non-zero values in a column or row may be only mapped on indexes based on the index of antenna ports in the one or two groups.
  • a first group may comprise 4 antenna ports, and the 4 antenna ports may be ⁇ AP0, AP1, AP2, AP3 ⁇ .
  • a second group may comprise 4 antenna ports, and the 4 antenna ports may be ⁇ AP4, AP5, AP6, AP7 ⁇ .
  • one of length-4 vectors in the first set or second set of length-4 vectors may be mapped on the indexes of elements based on the antenna port indexes in the first group and/or the second group.
  • a set of length-4 vectors may be mapped on element with indexes based on the 4 antenna ports in the first group, and for a second set of 4 columns or rows (e.g. the remaining or last 4 columns or rows) , a set of length-4 vectors may be mapped on elements with indexes based on the 4 antenna ports in the second group.
  • a set of length-2 vectors may be mapped on elements with indexes based on two out of the 4 antenna ports in the first group, and for a second set of 2 columns or rows (e.g. the third and fourth columns or rows) , a set of length-2 vectors may be mapped on elements with indexes based on remaining two antenna ports in the first group, and for a third set of 2 columns or rows (e.g.
  • a set of length-2 vectors may be mapped on element with indexes based on two out of the 4 antenna ports in the second group, and for a fourth set of 2 columns or rows (e.g. the seventh and eighth columns or rows) , a set of length-2 vectors may be mapped on elements with indexes based on remaining two antenna ports in the second group.
  • the indexes of the 2 non-zero values may be based on the indexes of two out of the four antenna port indexes in a group.
  • the non-zero values in a column or row may be only mapped on indexes based on the index of antenna ports in the one or two groups.
  • a first group with 4 antenna ports may be ⁇ AP0, AP1, AP2, AP3 ⁇ .
  • a second group with 4 antenna ports may be ⁇ AP4, AP5, AP6, AP7 ⁇ .
  • one of length-2 vectors in the first set or second set of length-2 vectors may be mapped on the indexes of elements based on two out of 4 antenna port indexes in the first group and/or the second group.
  • the indexes of the 1 non-zero value may be based on the indexes of one out of the four antenna port indexes in a group.
  • the non-zero values in a column or row may be only mapped on indexes based on the index of antenna ports in the one or two groups.
  • a first group with 4 antenna ports may be ⁇ AP0, AP1, AP2, AP3 ⁇ .
  • a second group with 4 antenna ports may be ⁇ AP4, AP5, AP6, AP7 ⁇ .
  • the value 1 in a column or row of the precoding matrix, the value 1 may be mapped on the index of elements based on one out of 4 antenna port indexes in the first group and/or the second group.
  • the at least one configuration may indicate one or two or three or four groups of antenna ports, and each group may comprise 2 antenna ports, and based on the at least one configuration, a DCI may indicate one precoding matrix from the second subset of precoding matrixes corresponding to v_ri layers for the PUSCH transmission.
  • the indexes of the 2 non-zero values may be based on the indexes of antenna port indexes in a group. For example, the non-zero values in a column or row may be only mapped on indexes based on the index of antenna ports in the one or two or three or four groups.
  • one of length-2 vectors in the first set or second set of length-2 vectors may be mapped on the indexes of elements based on the antenna port indexes in the third group and/or the fourth group and/or the fifth group and/or the sixth group.
  • FIG. 2 shows a signaling chart illustrating process 200 among the terminal device and the network device according to some example embodiments of the present disclosure. Only for the purpose of discussion, the process 200 will be described with reference to FIG. 1. For example, the process 200 may involve the terminal device 110 and the network device 120.
  • the network device 120 transmits 2010 first information associated with at least one first precoding matrix to the terminal device 110.
  • the first information may be included in a downlink control information (DCI) field.
  • the DCI field may indicate an index of the at least one first precoding matrix.
  • the first precoding matrix may be a discrete Fourier transform (DFT) based precoding matrix.
  • the first precoding matrix may be a first downlink type precoding matrix.
  • the first precoding matrix may be Rel-15 DL typeI precoder.
  • the network device 120 transmits 2020 second information to the terminal device 110.
  • the second information is associated with a set of phase offsets for the at least one first precoding matrix.
  • a phase offset in the set of phase offsets may be between antennas of the terminal device 110.
  • the terms “antenna” and “antenna ports” can be used interchangeable.
  • the second information may be transmitted via medium access control (MAC) signaling.
  • the second information may be transmitted via radio resource control (RRC) signaling.
  • MAC medium access control
  • RRC radio resource control
  • the number of phase offsets in the set of phase offsets may be less than the number of rows or the number of columns in each one of the at least one first precoding matrix. In some embodiments, the number of phase offsets may be one of: 7, 6, 3, or 2.
  • the set of phase offsets may be same for layers of each one of the at least one first precoding matrix.
  • the set of phase offsets may be layer common.
  • a phase offset in the set of phase offsets may be at least one of: ⁇ 1, j, -1, -j ⁇ . In some other embodiments, a phase offset in the set of phase offsets may be e j*2 ⁇ *m/M , where M is at least one of ⁇ 4, 8, 16 ⁇ , and m is an integer from 0 to M-1.
  • a default value of a phase offset may be a predetermined value.
  • the value of the phase offset may be 1.
  • the network device 120 may transmit a configuration indicating a valid duration for the set of phase offsets to the terminal device 110.
  • the terminal device 110 may be configured with a valid duration for the phase offset.
  • the configuration may be transmitted via RRC signaling.
  • the configuration may be transmitted via MAC signaling.
  • the number of the set of phase offsets may be 7.
  • ⁇ e j*2 ⁇ *b (0) , e j*2 ⁇ *b (1) , e j*2 ⁇ *b (2) , e j*2 ⁇ *b (3) , e j*2 ⁇ *b (4) , e j*2 ⁇ *b (5) , e j*2 ⁇ *b (6) ⁇ at least one of the values of ⁇ b (0) , b (1) , b (2) , b (3) , b (4) , b (5) , b (6) ⁇ may be fixed as 0. For example, no need of configuration/indication for the values fixed as 0.
  • the value of b (3) may be fixed as 0.
  • the value of b (0) and/or the value of the value of b (1) and/or the value of the value of b (3) and/or the value of the value of b (5) may be fixed as 0.
  • the value of b (0) and/or the value of the value of b (1) and/or the value of the value of b (2) and/or the value of the value of b (3) and/or the value of the value of b (5) may be fixed as 0.
  • the value of b (0) and/or the value of the value of b (1) and/or the value of the value of b (2) and/or the value of the value of b (4) and/or the value of the value of b(5) may be fixed as 0.
  • the terminal device 110 determine 2030 a second precoding matrix based on the at least one first precoding matrix and the second information.
  • the terminal device 110 performs 2040 a transmission to the network device on a physical uplink shared channel (PUSCH) based on the second precoding matrix. In this way, the overhead can be reduced.
  • PUSCH physical uplink shared channel
  • the terminal device 110 may be configured with at least one of Table 1 or Table 2 as below.
  • Table 1 Mapping of i 1, 3 to k 1 and k 2 for 2-layer CSI reporting
  • Table 2 Mapping of i 1, 3 to k 1 and k 2 for 3-layer and 4-layer CSI reporting when P CSI-RS ⁇ 16
  • g may be one of: Alternatively, g may be one of:
  • the first precoding matrix may be one precoder/precoding matrix of Rel-15 DL TypeI codebook.
  • the first precoding matrix may be:
  • the second precoding matrix may be:
  • e j*2 ⁇ *b (m) may represent the m-th phase offset.
  • the second precoding matrix may be:
  • (N1, N2) (4, 1) , l ⁇ 0, 1, ...O 1 N 1 -1 ⁇ .
  • l′ l+k1.
  • k1 may be at least one of 0, O 1 , 2O 1 , 3O 1 .
  • (N1, N2) (2, 2) , l ⁇ 0, 1, ...O 1 N 1 -1 ⁇ , m ⁇ ⁇ 0, 1, ...O 2 N 2 -1 ⁇ .
  • l′ l+k1
  • m′ m+k2
  • k1 may be at least one of 0, O 1
  • k2 may be at least one of 0, O 2 .
  • the second precoding matrix may be:
  • (N1, N2) (4, 1) , l ⁇ 0, 1, ...O 1 N 1 -1 ⁇ .
  • l′ l+k1.
  • k1 may be at least one of 0, O 1 , 2O 1 , 3O 1 .
  • for (N1, N2) (2, 2) , l ⁇ 0, 1, ...O 1 N 1 -1 ⁇ , m ⁇ 0, 1, ...O 2 N 2 -1 ⁇ .
  • l′ l+k1
  • m′ m+k2.
  • the second precoding matrix may be
  • (N1, N2) (4, 1) , l ⁇ 0, 1, ...O 1 N 1 -1 ⁇ .
  • l′ l+k1 .
  • k1 may be at least one of 0, O1, 2O1, 3O1.
  • for (N1, N2) (2, 2) , l ⁇ 0, 1, ...O 1 N 1 -1 ⁇ , m ⁇ ⁇ 0, 1, ...O 2 N 2 -1 ⁇ .
  • the second precoding matrix may be:
  • (N1, N2) (4, 1) , l ⁇ 0, 1, ...O 1 N 1 -1 ⁇ .
  • l′ l+O 1 .
  • l′′ l+2O 1 .
  • for (N1, N2) (2, 2) , l ⁇ ⁇ 0, 1, ...O 1 N 1 -1 ⁇ , m ⁇ ⁇ 0, 1, ...O 2 N 2 -1 ⁇ .
  • the second precoding matrix may be:
  • (N1, N2) (4, 1) , l ⁇ 0, 1, ...O 1 N 1 -1 ⁇ .
  • l′ l+O 1 .
  • l′′ l+2O 1 .
  • for (N1, N2) (2, 2) , l ⁇ 0, 1, ...O 1 N 1 -1 ⁇ , m ⁇ ⁇ 0, 1, ...O 2 N 2 -1 ⁇ .
  • the second precoding matrix may be:
  • (N1, N2) (4, 1) , l ⁇ 0, 1, ...O 1 N 1 /2-1 ⁇ .
  • l′ l+O 1 .
  • l′′ l+2O 1 .
  • l′′ l+3O 1 .
  • for (N1, N2) (2, 2) , l ⁇ 0, 1, ...O 1 N 1 -1 ⁇ , m ⁇ ⁇ 0, 1, ...O 2 N 2 -1 ⁇ .
  • the second precoding matrix may be:
  • (N1, N2) (4, 1) , l ⁇ 0, 1, ...O 1 N 1 /2-1 ⁇ .
  • l′ l+O 1 .
  • l′′ l+2O 1 .
  • l′′ l+3O 1 .
  • for (N1, N2) (2, 2) , l ⁇ 0, 1, ...O 1 N 1 -1 ⁇ , m ⁇ ⁇ 0, 1, ...O 2 N 2 -1 ⁇ .
  • the number of phase offsets may be 6.
  • the number of phase offsets may be 6, as can already adjust the phase difference.
  • the second precoding matrix may be:
  • the value of the phase offset is at least one of ⁇ 1, j, -1, -j ⁇
  • the number of phase offsets may be 3 or 2.
  • the second precoding matrix may be:
  • the second precoding matrix may be:
  • the second precoding matrix may be:
  • FIG. 3 shows a signaling chart illustrating process 300 among the terminal device and the network device according to some example embodiments of the present disclosure. Only for the purpose of discussion, the process 300 will be described with reference to FIG. 1. For example, the process 300 may involve the terminal device 110 and the network device 120.
  • the network device 120 transmits 3010 first information associated with a subset of precoding matrixes to the terminal device 110.
  • precoding matrixes in the subset may be based on a plurality of discrete Fourier transform (DFT) based precoding matrixes.
  • DFT discrete Fourier transform
  • the precoding matrixes in the subset may be based on first downlink type precoding matrixes and a set of phase offsets between antennas of the terminal device.
  • the first information may be transmitted via MAC signaling.
  • the first information may be transmitted via RRC signaling.
  • the subset may comprise the precoding matrix as described with reference to FIG. 2.
  • the subset may comprise one or more of: 1-layer precoder, 2-layer precoder, 3-layer precoder, 4-layer precoder, 5-layer precoder, 6-layer precoder, 7-layer precoder, or 8-layer precoder.
  • the network device 120 transmits 3020 second information indicating a precoding matrix in the subset of precoding matrixes to the terminal device 110.
  • a bit size for indicating the second information may be based on the number of precoding matrixes in the subset of first precoding matrixes.
  • the number of candidate values for indicating the codebook subset may be one of: 28, 24, 12, or 8.
  • the bitsize may be ceil (log2 (Nc) ) , where Nc represents the candidate value.
  • the terminal device 110 performs 3030 a transmission based on the indicated precoding matrix.
  • the indicated precoding matrix may be based on two precoding matrixes and a phase offset between the two precoding matrixes. In this way, it can reduce the DCI overhead and solve the TAE issue.
  • FIG. 4 shows a signaling chart illustrating process 400 among the terminal device and the network device according to some example embodiments of the present disclosure. Only for the purpose of discussion, the process 400 will be described with reference to FIG. 1. For example, the process 400 may involve the terminal device 110 and the network device 120.
  • the network device 120 transmits 4010 DCI to the terminal device 110.
  • the DCI includes a first field that indicates a first precoding matrix.
  • the DCI also includes a second field that indicates a parameter which is based on the first field.
  • the first field may be a transmission precoding matrix indicator (TPMI) field.
  • TPMI transmission precoding matrix indicator
  • the first field may be any proper field in DCI.
  • the DCI 500 may comprise the first field 510 and the second field 520. It is noted that FIG. 5 is only an example not limitation.
  • the terminal device may be configured with at least one first full coherent precoder. In some embodiments, if the terminal device reports capability of supporting second full coherent precoder, the terminal device may be configured with at least one second full coherent precoder.
  • the terminal device 110 determines 4020 a second precoding matrix based on the firs precoding matrix and the parameter.
  • the terminal device 110 performs 4030 a transmission based on the second precoding matrix. In this way, it can reduce the DCI overhead.
  • the terminal device 110 may be configured with a sounding reference signal (SRS) resource set for 8 antenna transmission.
  • the SRS resource set may comprise at least one SRS resource.
  • Each SRS resource in the SRS resource set may comprise 8 ports.
  • the second field may indicate at least one phase offset between antennas.
  • the first field indicates a full coherent precoder or the value of the first field is in a first range
  • the second field may indicate the phase offset from ⁇ 1, j, -1, -j ⁇ .
  • the terminal device 110 may determine the second precoding matrix based on the full coherent precoder indicated in the first field and the phase offset indicated in the second field.
  • the second field may indicate The second precoding matrix for 1-layer determined by the terminal device 110 may be
  • the first precoding matrix may be one precoder/precoding matrix of Rel-15 DL TypeI codebook. In some embodiments, the first precoding matrix may be:
  • the second precoding matrix may be:
  • e j*2 ⁇ *b (m) may represent the m-th phase offset.
  • the second precoding matrix may be:
  • (N1, N2) (4, 1) , l ⁇ 0, 1, ...O 1 N 1 -1 ⁇ .
  • l′ l+k1.
  • k1 may be at least one of 0, O 1 , 2O 1 , 3O 1 .
  • (N1, N2) (2, 2) , l ⁇ 0, 1, ...O 1 N 1 -1 ⁇ , m ⁇ ⁇ 0, 1, ...O 2 N 2 -1 ⁇ .
  • l′ l+k1
  • m′ m+k2
  • k1 may be at least one of 0, O 1
  • k2 may be at least one of 0, O 2 .
  • the second precoding matrix may be:
  • (N1, N2) (4, 1) , l ⁇ 0, 1, ...O 1 N 1 -1 ⁇ .
  • l′ l+k1.
  • k1 may be at least one of 0, O 1 , 2O 1 , 3O 1 .
  • for (N1, N2) (2, 2) , l ⁇ 0, 1, ...O 1 N 1 -1 ⁇ , m ⁇ 0, 1, ...O 2 N 2 -1 ⁇ .
  • l′ l+k1
  • m′ m+k2.
  • the second precoding matrix may be
  • (N1, N2) (4, 1) , l ⁇ 0, 1, ...O 1 N 1 -1 ⁇ .
  • l′ l+k1 .
  • k1 may be at least one of 0, O1, 2O1, 3O1.
  • for (N1, N2) (2, 2) , l ⁇ 0, 1, ...O 1 N 1 -1 ⁇ , m ⁇ ⁇ 0, 1, ...O 2 N 2 -1 ⁇ .
  • the second precoding matrix may be:
  • (N1, N2) (4, 1) , l ⁇ 0, 1, ...O 1 N 1 -1 ⁇ .
  • l′ l+O 1 .
  • l′′ l+2O 1 .
  • for (N1, N2) (2, 2) , l ⁇ 0, 1, ...O 1 N 1 -1 ⁇ , m ⁇ ⁇ 0, 1, ...O 2 N 2 -1 ⁇ .
  • the second precoding matrix may be:
  • (N1, N2) (4, 1) , l ⁇ 0, 1, ...O 1 N 1 -1 ⁇ .
  • l′ l+O 1 .
  • l′′ l+2O 1 .
  • for (N1, N2) (2, 2) , l ⁇ 0, 1, ...O 1 N 1 -1 ⁇ , m ⁇ ⁇ 0, 1, ...O 2 N 2 -1 ⁇ .
  • the second precoding matrix may be:
  • (N1, N2) (4, 1) , l ⁇ 0, 1, ...O 1 N 1 /2-1 ⁇ .
  • l′ l+O 1 .
  • l′′ l+2O 1 .
  • l′′ l+3O 1 .
  • for (N1, N2) (2, 2) , l ⁇ 0, 1, ...O 1 N 1 -1 ⁇ , m ⁇ ⁇ 0, 1, ...O 2 N 2 -1 ⁇ .
  • the second precoding matrix may be:
  • (N1, N2) (4, 1) , l ⁇ 0, 1, ...O 1 N 1 /2-1 ⁇ .
  • l′ l+O 1 .
  • l′′ l+2O 1 .
  • l′′ l+3O 1 .
  • for (N1, N2) (2, 2) , l ⁇ 0, 1, ...O 1 N 1 -1 ⁇ , m ⁇ ⁇ 0, 1, ...O 2 N 2 -1 ⁇ .
  • the number of phase offsets may be 6.
  • the number of phase offsets may be 6, as can already adjust the phase difference.
  • the second precoding matrix may be:
  • the value of the phase offset is at least one of ⁇ 1, j, -1, -j ⁇
  • the number of phase offsets may be 3 or 2.
  • the second precoding matrix may be:
  • the second precoding matrix may be:
  • the second field may indicate an index of a group of antennas and the first precoding matrix is mapped on rows or columns corresponding to the group of antennas.
  • the group of antennas may be from 4 groups of antennas, and each group may include 2 antennas.
  • the second field may indicate the index of antenna port group from ⁇ group 0, group 1, group 2, group 3 ⁇ .
  • the group of antennas may be from 2 groups of antennas, and each group may include 4 antennas.
  • the second field may indicate the index of antenna port group from ⁇ group 0, group 1 ⁇ .
  • the first field indicates a length-4 or length-2 vector
  • the second field may indicate a group with the 4 or 2 antenna ports to be mapped with the vector.
  • the first field may indicate the fir precoding matrix indicates (e.g. one of 4Tx UL codebook)
  • the second field may indicate group 0 or group 1.
  • the second precoding matrix for 1-lyaer may be if coherent group is ⁇ 0, 1, 4, 5 ⁇ ⁇ 2, 3, 6, 7 ⁇ , and group 0 is indicated.
  • the second field may indicate an index of a group of antennas and the first precoding matrix is mapped on rows or columns corresponding to the group of antennas.
  • the second field may indicate the antenna port group from ⁇ group 0, group 1 ⁇ or ⁇ group 0, group 1, group 2, group 3 ⁇ .
  • the second field may indicate the antenna port index from ⁇ port 0, port 1, port 2, port 3, port 4, port 5, port 6, port 7, port 8 ⁇ .
  • the first field may indicate the first precoding matrix (e.g. one of 4Tx UL non-coherent codebook)
  • the second field may indicate group 0 or group 1.
  • the second precoding matrix for 1-layer may be:
  • the second field may indicate which one of the 8 ports.
  • the terminal device 110 may be configured with at least four 2-port SRS resources or at least two 4-port SRS resources.
  • the at least four 2-port SRS resource may be within one or a plurality of SRS resource set, and the at least two 4-port SRS resources may be within one or a plurality of SRS resource set.
  • the second field may be a SRS resource indicator field.
  • the second field may be ignored.
  • the first precoding is a full coherent precoding matrix or a value of the first field is in a first range
  • the second field may indicate at least one phase offset between antennas.
  • the second field may indicate an index of a SRS resource.
  • the first precoding matrix may be mapped on rows or columns corresponding to a group of antennas associated with the SRS resource.
  • the second field may indicate an index of a SRS resource.
  • the first precoding matrix may be mapped on rows or columns corresponding to a group of antennas associated with the SRS resource.
  • the terminal device may be configured with at least 4 SRS resource sets where each RSR resource set comprises at least one 2-port SRS resource.
  • the terminal device may be configured with at least 2 SRS resource sets where each SRS resource set comprises at least 4-port SRS resource.
  • the first precoding matrix is a full coherent precoding matrix or a value of the first field in is a first range
  • the second field may be ignored.
  • the second field may indicate an index of SRS resource in each SRS resource set.
  • the first precoding matrix is a partial coherent precoding matrix or a value of the first field in is at least one of: a second range or a third range
  • the second field may indicate an index of a SRS resource set.
  • the first precoding matrix may be mapped on rows or columns corresponding to a group of antennas associated with the SRS resource set.
  • the second field may indicate an index of a SRS resource set.
  • the first precoding matrix is mapped on rows or columns corresponding to a group of antennas associated with the SRS resource set.
  • the DCI may indicate which full coherent precoding matrixes for the terminal device 110.
  • the at least one configuration comprises none or at least one of: a first full coherent precoding matrix or a second full coherent precoding matrix.
  • the at least one configuration may indicate none or one or both of Set_fv_1 and Set_fv_2.
  • the at least one configuration comprises one or more of a number of antenna ports in a first dimension, a number of antenna ports in a second dimension, a first DFT oversampling in the first dimension, or a second DFT oversampling in the second dimension.
  • the at least one configuration may indicate candidate values for at least one of N1, N2, i1, 1, O1, O2, i1, 2, i1, 3 to generate the precoding matrix.
  • the DCI may indicate which partial coherent precoding matrixes for the terminal device 110.
  • the at least one configuration may indicate that if there is at least one antenna port group with 4 antenna ports, at least one column or at least one row of the precoding matrix is with 4 non-zero values on 4 of the 8 elements.
  • the indexes of the 4 elements may be based on the indexes of the 4 antenna ports in one antenna port group, and zero values on other 4 of the 8 elements in the column or the row.
  • the at least one configuration may indicate that if there is at least one group with 4 ports, at least one column of the precoder can be with 4 non-zero values (mapping on the 4 indexes (AP_i+1) ) . Otherwise, there may be no such kind of precoders.
  • the bit size for the first field and/or for the second field and/or for the third field may be at least one of 1 bit, 2 bits, 3 bits and 4 bits.
  • the at least one configuration may indicate that if there is at least one antenna port group with 2 antenna ports, at least one column or at least one row of the precoding matrix is with 2 non-zero values on 2 of the 8 elements.
  • the indexes of the 2 elements may be based on the indexes of the 2 antenna ports in one antenna port group, and zero values on other 6 of the 8 elements in the column or the row.
  • the at least one configuration may indicate that if there is at least one group with 2 ports, at least one column of the precoder can be with 2 non-zero values (mapping on the 2 indexes (AP_i+1) ) , otherwise, there is no such kind of precoders.
  • At least one configuration may indicate that if there is at least one antenna port group with 1 antenna port, at least one column or at least one row of the precoding matrix is with 1 non-zero value on 1 of the 8 elements, and the non-zero value is 1.
  • the index of the 1 element may be based on the index of the antenna port in one antenna port group, and zero values on other 7 of the 8 elements in the column or the row.
  • a set of non-coherent precoding matrixes associated with the fourth number may be available for the PUSCH.
  • each column or each row of the non-coherent precoding matrix may be with 1 non-zero value on 1 of the 8 elements.
  • the non-zero value may be 1.
  • the index of the 1 element may be based on the index of the antenna port in one antenna port group, and zero values on other 7 of the 8 elements in the column or the row.
  • the indexes of the 1 element in different columns or different rows may be based on different antenna port groups.
  • the third number is larger than the fourth number, a set of non-coherent precoding matrixes associated with the fourth number may not be available for the PUSCH.
  • the set of non-coherent precoding matrixes may be not available for the PUSCH.
  • the third number is at least one of: 1, 2, 3, 4, 5, 6, 7, 8, the set of non-coherent precoding matrixes may comprise at least a precoding matrix with each column or each row of the precoding matrix is with 1 non-zero value on 1 of the 8 elements, and the non-zero value is 1.
  • the index of the 1 element may be based on the index of column or row, and zero values on other 7 of the 8 elements in the column or the row.
  • the set of non-coherent precoding matrixes may comprise at least a precoding matrix with each column or each row of the precoding matrix is with 1 non-zero value on 1 of the first 4 elements, and the non-zero value is 1.
  • the index of the 1 element may be based on the index of column or row, and zero values on other 7 elements in the column or the row.
  • the set of non-coherent precoding matrixes may comprise that at least a precoding matrix with each column or each row of the precoding matrix is with 1 non-zero value on 1 of the 8 elements, and the non-zero value is 1.
  • the index of the 1 element in each column or row may be based on the index of each antenna port of the third number of antenna ports, and zero values on other 7 of the 8 elements in the column or the row.
  • the set of non-coherent precoding matrixes may comprise that at least a precoding matrix with each column or each row of the precoding matrix is with 1 non-zero value on 1 of the 8 elements, and the non-zero value is 1.
  • the index of the 1 element in each column or row may be based on the index of one antenna port, and the antenna port is one of the fourth number out of the third number of antenna ports, and zero values on other 7 of the 8 elements in the column or the row.
  • non-coherent precoding matrix associated with the fourth number may not be available for the PUSCH.
  • the at least one configuration may comprise an order of 8 antenna ports.
  • the set of non-coherent precoding matrixes associated with the fourth number may comprise that at least a precoding matrix with each column or each row of the precoding matrix is with 1 non-zero value on 1 of the 8 elements, and the non-zero value is 1.
  • the index of the 1 element in each column or row may be based on the index of one antenna port, and the antenna port is one of first fourth number of antenna ports out of the order of 8 antenna ports, and zero values on other 7 of the 8 elements in the column or the row.
  • the at least one configuration may indicate precoding matrixes with that a first set of antenna port elements in a 4-antenna port group is mapped with non-zero values.
  • the at least one configuration may indicate that precoding matrixes with that a second set of antenna port elements in a 2-antenna port group is mapped with non-zero values.
  • the at least one configuration may indicate that the precoding matrixes with that a third set of antenna port elements which is not in the 4-antenna port group or 2-antenna port group is mapped with non-zero values.
  • the at least one configuration may indicate that precoding matrixes with that the first third number of antenna ports elements are used for mapping non-zero values in the third number of columns in the precoding matrix.
  • non-coherent precoding matrix (Set_n8_1) if the number of layers is 8, there may be only one non-coherent precoding matrix (Set_n8_1) .
  • the non-coherent precoding matrix may always be included.
  • the number of layers (represented as “v” ) is 7, there may be only one non-coherent precoding matrix.
  • the non-coherent precoding matrix may always be included.
  • the non-zero value may be mapped on the 7 AP_i+1 indexes. If L is 8, the non-zero value may be mapped on C (L, 7) AP_i+1 indexes. Otherwise the non-coherent precoder p_n7_1 is included.
  • the values of AP_i included in a 4-port group may be used firstly, then values of AP_i included in a 2-port group may be used, then values of AP_i not included in any one of 4-port group or 2-port group may be used.
  • the lowest 7 indexes are used. For example, if N 1 is 2 or N 2 is 2, p_n7_1 may be included. Alternatively, if N 1 is 1 or N 2 is 1, and M 1 is 1, AP_i included in the 4-port group and the two 2-port groups may be used, and the one with lower value in remaining two APs may be used. In some embodiments, if N 1 is 1 or N 2 is1, and M 1 is 0, AP_i included in the 4-port group may be used, and the three ones with lower values in remaining four APs may be used. Alternatively, the first 7 APs in config_n1 may be used for mapping the value 1 in 7 columns.
  • the number of layers (represented as “v” ) is 6, there may be only one non-coherent precoding matrix.
  • the non-coherent precoding matrix may always be included.
  • the non-zero value may be mapped on the 6 AP_i+1 indexes.
  • the non-zero values may be mapped on C (L, 6) AP_i+1 indexes. Otherwise the non-coherent p_n6_1 precoder may be included.
  • the values of AP_i included in a 4-port group may be used firstly, then values of AP_i included in a 2-port group may be used, then values of AP_i not included in any one of 4-port group or 2-port group may be used. And if there are more than 6 available values of AP_i, the lowest 6 indexes may be used.
  • the first 6 APs in config_n1 may be used for mapping the value 1 in 6 columns.
  • the number of layers (represented as “v” ) is 5, there may be only one non-coherent precoding matrix.
  • the non-coherent precoding matrix may always be included.
  • the non-zero value may be mapped on the 6 AP_i+1 indexes.
  • the non-zero value may be mapped on C (L, 5) AP_i+1 indexes. Otherwise the non-coherent precoder p_n5_1 may be included.
  • the values of AP_i included in a 4-port group may be used firstly, then values of AP_i included in a 2-port group may be used, then values of AP_i not included in any one of 4-port group or 2-port group may be used. And if there are more than 5 available values of AP_i, the lowest 5 indexes may be used.
  • the first 5 APs in config_n1 may be used for mapping the value 1 in 5 columns.
  • the number of layers (represented as “v” ) is 4, there may be only one non-coherent precoding matrix.
  • the non-coherent precoding matrix may always be included.
  • the non-zero value may be mapped on the 4 AP_i+1 indexes.
  • the non-zero value may be mapped on C (L, 4) AP_i+1 indexes. Otherwise the non-coherent p_n4_1 precoder may be included.
  • the values of AP_i included in a 4-port group may be used firstly, then values of AP_i included in a 2-port group may be used, then values of AP_i not included in any one of 4-port group or 2-port group may be used. And if there are more than 4 available values of AP_i, the lowest 4 indexes are used. For example, if N 1 is 1, N 2 is 2 or N 3 is 2, there may be two non-coherent precoders, each precoder with value one mapping on AP_i+1 index in a column, where AP_i is in one group.
  • N 1 is 1 or N 2 is 1 or N 3 is 1, there may be one non-coherent precoder, with value one mapping on AP_i+1 index in a column, and AP_i is in the group.
  • N 1 /N 2 /N 3 is 0, and M 1 or M 2 or M 3 is not smaller than 2
  • the AP_i included in the M1 or M2 or M3 groups may be used, the non-zero value may be mapped on AP_i included in C (M3, 2) groups.
  • the first 4 APs in config_n1 may be used for mapping the value 1 in 4 columns.
  • the number of layers (represented as “v” ) is 3, there may be only one non-coherent precoding matrix.
  • the non-coherent precoding matrix may always be included.
  • the non-zero value may be mapped on the 3 AP_i+1 indexes.
  • L is larger than 3, the non-zero value may be mapped on C (L, 3) AP_i+1 indexes. Otherwise the non-coherent p_n3_1 precoder may be included.
  • the values of AP_i included in a 4-port group may be used firstly, then values of AP_i included in a 2-port group may be used, then values of AP_i not included in any one of 4-port group or 2-port group may be used.
  • the lowest 3 indexes may be used. For example, if N 1 is 2 or N 2 is 2 or N 3 is 2, the non-zero value may be mapped on element with index AP_i+1, and three values of AP_i may be selected in one group. There may be 2*C (4, 3) non-coherent precoders, each precoder with value one mapping on AP_i+1 index in a column, where AP_i is in one group.
  • N 1 is 1 or N 2 is 1 or N 3 is 1, there may C (4, 3) non-coherent precoders, with value one mapping on AP_i+1 index in a column, and three AP_i selected in the group.
  • the AP_i included in the M1 or M2 or M3 groups may be used, the non-zero value may be mapped on AP_i includes in C (M3, 2) groups and C (4, 3) AP_i+1 indexes (or three lowest AP_i+1 indexes) .
  • the first 3 APs in config_n1 may be used for mapping the value 1 in 3 columns.
  • the number of layers (represented as “v” ) is 2, there may be only one non-coherent precoding matrix.
  • the non-coherent precoding matrix may always be included.
  • the non-zero value may be mapped on the 2 AP_i+1 indexes.
  • L is larger than 2
  • the non-zero value may be mapped on C (L, 2) AP_i+1 indexes. Otherwise the non-coherent p_n2_1 precoders may be included.
  • the values of AP_i included in a 4-port group may be used firstly, then values of AP_i included in a 2-port group may be used, then values of AP_i not included in any one of 4-port group or 2-port group may be used.
  • the lowest 3 indexes may be used. For example, if N 1 is 2 or N 2 is 2 or N 3 is 2, the non-zero value may be mapped on element with index AP_i+1, and two values of AP_i may be selected in one group. There may be 2*C (4, 2) non-coherent precoders, each precoder with value one mapping on AP_i+1 index in a column, where AP_i is in one group.
  • N 1 is1 or N 2 is 1 or N 3 is 1, there may be C (4, 2) non-coherent precoders, with value one mapping on AP_i+1 index in a column, and two AP_i may be selected in the group.
  • N 1 /N 2 /N 3 is 0, and M 1 or M 2 or M 3 is not smaller than 2, the AP_i included in the M 1 or M 2 or M 3 groups may be used, the non-zero value may be mapped on AP_i includes in C (M3, 1) groups and the two APi+1 indexes.
  • the first 2 APs in config_n1 may be for mapping the non-zero value in two columns.
  • the number of layers (represented as “v” ) 1, there may be only one non-coherent precoding matrix.
  • the non-coherent precoding matrix may always be included.
  • the non-zero value may be mapped on the AP_i+1 index.
  • the non-zero value may be mapped on C (L, 1) AP_i+1 index. Otherwise the non-coherent p_n1_1 precoders may be included.
  • the values of AP_i included in a 4-port group may be used firstly, then values of AP_i included in a 2-port group may be used, then values of AP_i not included in any one of 4-port group or 2-port group may be used. And if there are more than 3 available values of AP_i, the lowest 3 indexes may be used. For example, if N 1 is 2 or N 2 is 2 or N 3 is 2, the non-zero value may be mapped on element with index AP_i+1, and one value of AP_i may be selected in one group.
  • N 1 is 1 or N 2 is 1 or N 3 is 1
  • the AP_i included in the M 1 or M 2 or M 3 groups may be used, the non-zero value may be mapped on AP_i includes in C (M3, 1) groups and the one of the two APi+1 indexes or fixed to the first one in the group.
  • the first AP in config_n1 may be used for mapping the non-zero value.
  • the terminal device 110 may receive information indicating that the PUSCH is scheduled associated with 8 antenna ports or associated with an SRS with 8 antenna ports.
  • the DCI may indicate the fourth number of layers which is not smaller than a minimum number of layers and the minimum number of layers is one of 4, 5, 6, 7, or 8.
  • the minimum number of layers may be predetermined or configured via higher layer.
  • the terminal device 110 may expect that the PUSCH is scheduled associated with 1 or 2 or 4 antenna ports or associated with an SRS with 1 or 2 or 4 antenna ports.
  • the number of layers indicated by a DCI may be at least one of ⁇ 4, 5, 6, 7, 8 ⁇ .
  • the candidate number of layers may be at least 4, for example, Lmin configured by RRC, and Lmin may be any one of ⁇ 4, 5, 6, 7, 8 ⁇ .
  • the precoding matrix for PUSCH transmission may be based on the indicated number of layers.
  • PUSCH transmission based on 8-port SRS is not expected to be 1-3 layers.
  • the terminal device 110 may be configured with SRS resource set with maximum number of SRS ports to be 1 or 2 or 4.
  • the 4-8 layers transmission with 8-port SRS and 1-3 (or 1-4) layers transmission based on 1/2/4-port SRS may be switched based on RRC or medium access control control element (MAC CE) .
  • MAC CE medium access control control element
  • the network device 120 may transmit a configuration of a set of SRS resources to the terminal device 110.
  • a first subset of SRS resources in the set of SRS resources may be configured with 8 SRS ports
  • a second subset of SRS resources in the set of SRS resources may be configured with a number of SRS ports which is not larger than 4.
  • the total bit size may be a maximum value between total size of “Precoding information and number of layers” and “Antenna ports” and a set of MCS/NDI/RV (8bit) for 1-3 (or 1-4) layers and total size of “Precoding information and number of layers” and “Antenna ports” and two sets of MCS/NDI/RV (16bits) for PUSCH transmission based on 8-port SRS.
  • reserved bits or zero padding may be applied for less value.
  • 8-port SRS may be configured in a first BWP
  • 1/2/4-port SRS may be configured in a second BWP.
  • switching between uplink transmission based on 8-port SRS and uplink transmission based on 1/2/4-port SRS can be based on BWP switching.
  • the network device 120 may transmit information indicating that the PUSCH is scheduled associated with 8 antenna ports or associated with an SRS with 8 antenna ports to the terminal device 110.
  • the terminal device 110 may apply applying at least one of: a subset of precoding matrixes or a subset of number of layers, before the reception of the at least one configuration.
  • a subset of precoders and/or a subset of number of layers may be applied as default.
  • non-coherent precoders may be used as the default precoding matrix.
  • the DCI may indicate the fourth number of layers in a separate field or combined in an antenna port field.
  • the DCI may also indicate a precoding matrix based on the fourth number of layers. For example, if the terminal device 110 is configured with 8Tx or 8-port SRS for uplink transmission, the number of layers may be separately indicated in a separate field (e.g. 3 bits) or jointly indicated with antenna ports field.
  • the precoding field may indicate the precoders based on the indicated number of layers.
  • the size of precoding field may be determined based on the maximum value among the number of precoders for different layers. For example, based on number of precoders for 1 layer or 2 layers.
  • the bit size for precoding field in DCI may be Y bits. Y may be positive integer, e.g. Y may be ⁇ 5, 6, 7, 8 ⁇ .
  • FIG. 6 shows a flowchart of an example method 600 in accordance with an embodiment of the present disclosure.
  • the method 600 can be implemented at any suitable terminal devices. Only for the purpose of illustrations, the method 600 can be implemented at a terminal device 110 as shown in FIG. 1.
  • the terminal device 110 receives first information associated with at least one first precoding matrix from the network device 120.
  • the first information may be comprised in a downlink control information (DCI) field, and the DCI field may indicate an index of the at least one first precoding matrix.
  • the at least one first precoding matrix may be a discrete Fourier transform (DFT) based precoding matrix.
  • the at least one first precoding matrix may be a first downlink type precoding matrix.
  • the terminal device 110 receives second information associated with a set of phase offsets for the first precoding matrix from the network device 120.
  • a phase offset in the set of phase offsets may be between antennas of the terminal device.
  • the second information may be transmitted via medium access control (MAC) signaling. In some embodiments, the second information may be transmitted via radio resource control (RRC) signaling.
  • MAC medium access control
  • RRC radio resource control
  • the set of phase offsets may be same for layers of each one of the at least one first precoding matrix. In some embodiments, the set of phase offsets are layer common.
  • the number of phase offsets in the set of phase offsets may be less than the number of rows or the number of columns in each one of the at least one first precoding matrix. In some embodiments, the number of phase offsets may be one of: 7, 6, 3, or 2.
  • a phase offset in the set of phase offsets may be at least one of: ⁇ 1, j, -1, -j ⁇ .
  • a phase offset in the set of phase offsets may be e j*2 ⁇ *m/M , and where M is at least one of ⁇ 4, 8, 16 ⁇ , and m is an integer from 0 to M-1.
  • a default value of a phase offset may be a predetermined value.
  • the terminal device 110 determines a second precoding matrix based on the at least one first precoding matrix and the second information.
  • the terminal device 110 may receive a configuration indicating a valid duration for the set of phase offsets from the network device 120.
  • the terminal device 110 transmits, to the network device 120, physical uplink shared channel (PUSCH) based on the second precoding matrix.
  • PUSCH physical uplink shared channel
  • FIG. 7 shows a flowchart of an example method 700 in accordance with an embodiment of the present disclosure.
  • the method 700 can be implemented at any suitable terminal devices. Only for the purpose of illustrations, the method 700 can be implemented at a terminal device 110 as shown in FIG. 1.
  • the terminal device 110 receives first information associated with a subset of precoding matrixes from the network device 120.
  • precoding matrixes in the subset may be based on a plurality of discrete Fourier transform (DFT) based precoding matrixes.
  • the precoding matrixes in the subset may be based on first downlink type precoding matrixes and a set of phase offsets between antennas of the terminal device 110.
  • DFT discrete Fourier transform
  • the terminal device 110 receives second information indicating a precoding matrix in the subset of precoding matrixes from the network device 120.
  • a bit size for indicating the second information is based on the number of precoding matrixes in the subset of first precoding matrixes.
  • a phase offset in the set of phase offsets may be between the first precoding matrixes.
  • the number of candidate values for indicating the codebook subset may be one of: 28, 24, 12, or 8.
  • the terminal device 110 performs a transmission to the network device 120 on a physical uplink shared channel (PUSCH) based on the indicated precoding matrix.
  • PUSCH physical uplink shared channel
  • FIG. 8 shows a flowchart of an example method 800 in accordance with an embodiment of the present disclosure.
  • the method 800 can be implemented at any suitable terminal devices. Only for the purpose of illustrations, the method 800 can be implemented at a terminal device 110 as shown in FIG. 1.
  • the terminal device 110 receives downlink control information from the network device 120.
  • the DCI includes a first field and a second field.
  • the first field indicates a first precoding matrix and the second field indicates a parameter that is based on the first field.
  • the terminal device 110 determines a second precoding matrix based on the first precoding matrix and the parameter.
  • the terminal device 110 may be configured with a sounding reference signal (SRS) resource set for 8 antenna transmission.
  • the SRS resource set may comprise at least one SRS resource, and each SRS resource in the SRS resource set may comprise 8 ports.
  • the second field may indicate at least one phase offset between antennas.
  • the first precoding matrix is a partial coherent precoding matrix or a value of the first field is in at least one of: a second range or a third range
  • the second field may indicate an index of a group of antennas and the first precoding matrix may be mapped on rows or columns corresponding to the group of antennas.
  • the first precoding matrix is a non-coherent precoding matrix or a value of the first field is in a fourth range
  • the second field may indicate an index of a group of antennas and the first precoding matrix may be mapped on rows or columns corresponding to the group of antennas.
  • the group of antennas may be from 4 groups of antennas and each group may comprise 2 antennas.
  • the group of antennas may be from 2 groups of antennas and each group may comprise 4 antennas.
  • the terminal device 110 may be configured with at least four 2-port SRS resources or at least two 4-port SRS resources.
  • the at least four 2-port SRS resource may be within one or a plurality of SRS resource set.
  • the at least two 4-port SRS resources may be within one or a plurality of SRS resource set.
  • the second field may be ignored.
  • the second field may indicate at least one phase offset between antennas.
  • the second field may indicate an index of a SRS resource.
  • the first precoding matrix may be mapped on rows or columns corresponding to a group of antennas associated with the SRS resource.
  • the second field may indicate an index of a SRS resource.
  • the first precoding matrix may be mapped on rows or columns corresponding to a group of antennas associated with the SRS resource.
  • the terminal device 110 may be configured with at least 4 SRS resource sets where each RSR resource set comprises at least one 2-port SRS resource. In some embodiments, the terminal device 110 may be configured with at least 2 SRS resource sets where each SRS resource set comprises at least 4-port SRS resource.
  • the second field may be ignored.
  • the second field may indicate an index of SRS resource in each SRS resource set.
  • the second field may indicate an index of a SRS resource set.
  • the first precoding matrix may be mapped on rows or columns corresponding to a group of antennas associated with the SRS resource set.
  • the second field may indicate an index of a SRS resource set.
  • the first precoding matrix may be mapped on rows or columns corresponding to a group of antennas associated with the SRS resource set.
  • the terminal device 110 performs an uplink transmission based on the second precoding matrix.
  • FIG. 9 shows a flowchart of an example method 900 in accordance with an embodiment of the present disclosure.
  • the method 900 can be implemented at any suitable terminal devices. Only for the purpose of illustrations, the method 900 can be implemented at a network device 120 as shown in FIG. 1.
  • the network device 120 transmits first information associated with at least one first precoding matrix to the terminal device 110.
  • the first information may be comprised in a downlink control information (DCI) field, and the DCI field may indicate an index of the at least one first precoding matrix.
  • DCI downlink control information
  • the at least one first precoding matrix may be a discrete Fourier transform (DFT) based precoding matrix.
  • the at least one first precoding matrix may be a first downlink type precoding matrix.
  • the network device 120 transmits second information associated with a set of phase offsets for the at least one first precoding matrix to the terminal device 110.
  • a phase offset in the set of phase offsets may be between antennas of the terminal device.
  • the second information may be transmitted via medium access control (MAC) signaling. In some embodiments, the second information may be transmitted via radio resource control (RRC) signaling.
  • MAC medium access control
  • RRC radio resource control
  • the set of phase offsets may be same for layers of each one of the at least one first precoding matrix. In some embodiments, the set of phase offsets are layer common.
  • the number of phase offsets in the set of phase offsets may be less than the number of rows or the number of columns in each one of the at least one first precoding matrix. In some embodiments, the number of phase offsets may be one of: 7, 6, 3, or 2.
  • a phase offset in the set of phase offsets may be at least one of: ⁇ 1, j, -1, -j ⁇ .
  • a phase offset in the set of phase offsets may be e j*2 ⁇ *m/M , and wher M is at least one of ⁇ 4, 8, 16 ⁇ , and m is an integer from 0 to M-1.
  • a default value of a phase offset may be a predetermined value.
  • the network device 120 receives a transmission on a physical uplink shared channel (PUSCH) from the terminal device 110.
  • the transmission is based on a second precoding matrix which is determined based on the at least one first precoding matrix and the second information.
  • the network device 120 may transmit to the terminal device 110, a configuration indicating a valid duration for the set of phase offsets.
  • FIG. 10 shows a flowchart of an example method 1000 in accordance with an embodiment of the present disclosure.
  • the method 1000 can be implemented at any suitable terminal devices. Only for the purpose of illustrations, the method 1000 can be implemented at a network device 120 as shown in FIG. 1.
  • the network device 120 transmits first information associated with a subset of precoding matrixes to the terminal device 110.
  • precoding matrixes in the subset may be based on a plurality of discrete Fourier transform (DFT) based precoding matrixes.
  • the precoding matrixes in the subset may be based on first downlink type precoding matrixes and a set of phase offsets between antennas of the terminal device 110.
  • DFT discrete Fourier transform
  • the network device 120 transmits second information indicating a precoding matrix in the subset of precoding matrixes to the terminal device 110.
  • a bit size for indicating the second information is based on the number of precoding matrixes in the subset of first precoding matrixes.
  • a phase offset may be between the first precoding matrixes.
  • the number of candidate values for indicating the codebook subset may be one of: 28, 24, 12, or 8.
  • the network device 120 receives a transmission on a physical uplink shared channel (PUSCH) from the terminal device 110.
  • the transmission is based on the indicated precoding matrix.
  • PUSCH physical uplink shared channel
  • FIG. 11 shows a flowchart of an example method 1100 in accordance with an embodiment of the present disclosure.
  • the method 1100 can be implemented at any suitable terminal devices. Only for the purpose of illustrations, the method 1100 can be implemented at a network device 120 as shown in FIG. 1.
  • the network device 120 transmits downlink control information to the terminal device 110.
  • the DCI comprises a first field and a second field.
  • the first field indicates a first precoding matrix and the second field indicates a parameter that is based on the first field.
  • the network device 120 receives a transmission based on a second precoding matrix that is based on the first precoding matrix and the parameter from the terminal device 110.
  • the second field may indicate at least one phase offset between antennas.
  • the first precoding matrix is a partial coherent precoding matrix or a value of the first field is in at least one of: a second range or a third range
  • the second field may indicate an index of a group of antennas and the first precoding matrix may be mapped on rows or columns corresponding to the group of antennas.
  • the second field may indicate an index of a group of antennas and the first precoding matrix may be mapped on rows or columns corresponding to the group of antennas.
  • the group of antennas may be from 4 groups of antennas and each group may comprise 2 antennas.
  • the group of antennas may be from 2 groups of antennas and each group may comprise 4 antennas.
  • the second field may be ignored.
  • the second field may indicate at least one phase offset between antennas.
  • the second field may indicate an index of a SRS resource.
  • the first precoding matrix may be mapped on rows or columns corresponding to a group of antennas associated with the SRS resource.
  • the second field may indicate an index of a SRS resource.
  • the first precoding matrix may be mapped on rows or columns corresponding to a group of antennas associated with the SRS resource.
  • the second field may be ignored.
  • the second field may indicate an index of SRS resource in each SRS resource set.
  • the second field may indicate an index of a SRS resource set.
  • the first precoding matrix may be mapped on rows or columns corresponding to a group of antennas associated with the SRS resource set.
  • the second field may indicate an index of a SRS resource set.
  • the first precoding matrix may be mapped on rows or columns corresponding to a group of antennas associated with the SRS resource set.
  • a terminal device comprises a circuitry configured to perform: the above methods.
  • a network device comprises a circuitry configured to perform the above methods.
  • circuitry used herein may refer to hardware circuits and/or combinations of hardware circuits and software.
  • the circuitry may be a combination of analog and/or digital hardware circuits with software/firmware.
  • the circuitry may be any portions of hardware processors with software including digital signal processor (s) , software, and memory (ies) that work together to cause an apparatus, such as a terminal device or a network device, to perform various functions.
  • the circuitry may be hardware circuits and or processors, such as a microprocessor or a portion of a microprocessor, that requires software/firmware for operation, but the software may not be present when it is not needed for operation.
  • the term circuitry also covers an implementation of merely a hardware circuit or processor (s) or a portion of a hardware circuit or processor (s) and its (or their) accompanying software and/or firmware.
  • a device of communication comprises: a processor configured to cause the device to perform any of the methods above.
  • 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 any of the methods above.
  • various embodiments of the present disclosure may be implemented in hardware or special purpose circuits, software, logic or any combination thereof. Some aspects may be implemented in hardware, while other aspects may be implemented in firmware or software which may be executed by a controller, microprocessor or other computing device. While various aspects of embodiments of the present disclosure are illustrated and described as block diagrams, flowcharts, or using some other pictorial representation, it will be appreciated that the blocks, apparatus, systems, techniques or methods described herein may be implemented in, as non-limiting examples, hardware, software, firmware, special purpose circuits or logic, general purpose hardware or controller or other computing devices, or some combination thereof.
  • the present disclosure also provides at least one computer program product tangibly stored on a non-transitory computer readable storage medium.
  • the computer program product includes computer-executable instructions, such as those included in program modules, being executed in a device on a target real or virtual processor, to carry out the process or method as described above with reference to FIGs. 1 to 4.
  • program modules include routines, programs, libraries, objects, classes, components, data structures, or the like that perform particular tasks or implement particular abstract data types.
  • the functionality of the program modules may be combined or split between program modules as desired in various embodiments.
  • Machine-executable instructions for program modules may be executed within a local or distributed device. In a distributed device, program modules may be located in both local and remote storage media.
  • Program code for carrying out methods of the present disclosure may be written in any combination of one or more programming languages. These program codes may be provided to a processor or controller of a general purpose computer, special purpose computer, or other programmable data processing apparatus, such that the program codes, when executed by the processor or controller, cause the functions/operations specified in the flowcharts and/or block diagrams to be implemented.
  • the program code may execute entirely on a machine, partly on the machine, as a stand-alone software package, partly on the machine and partly on a remote machine or entirely on the remote machine or server.
  • the above program code may be embodied on a machine readable medium, which may be any tangible medium that may contain, or store a program for use by or in connection with an instruction execution system, apparatus, or device.
  • the machine readable medium may be a machine readable signal medium or a machine readable storage medium.
  • a machine readable medium may include but not limited to an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing.
  • machine readable storage medium More specific examples of the machine readable storage medium would include an electrical connection having one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM) , a read-only memory (ROM) , an erasable programmable read-only memory (EPROM or Flash memory) , an optical fiber, a portable compact disc read-only memory (CD-ROM) , an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.
  • RAM random access memory
  • ROM read-only memory
  • EPROM or Flash memory erasable programmable read-only memory
  • CD-ROM portable compact disc read-only memory
  • magnetic storage device or any suitable combination of the foregoing.

Landscapes

  • Engineering & Computer Science (AREA)
  • Signal Processing (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Mobile Radio Communication Systems (AREA)

Abstract

Des modes de réalisation de la présente divulgation concernent des procédés, des dispositifs et un support lisible par ordinateur à des fins de communication. Selon des modes de réalisation de la présente divulgation, un dispositif de réseau transmet des premières informations associées à au moins une première matrice de précodage. Le dispositif de réseau fournit également des secondes informations associées à des informations de décalage de phase. Le dispositif terminal détermine une seconde matrice de précodage sur la base de la ou des premières matrices de précodage et des informations de décalage de phase. Le dispositif terminal effectue une transmission vers le dispositif de réseau sur un PUSCH sur la base de la seconde matrice de précodage. Il est ainsi possible de réduire le surdébit.
PCT/CN2022/128807 2022-10-31 2022-10-31 Procédé, dispositif et support d'enregistrement informatique de communication WO2024092470A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
PCT/CN2022/128807 WO2024092470A1 (fr) 2022-10-31 2022-10-31 Procédé, dispositif et support d'enregistrement informatique de communication

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/CN2022/128807 WO2024092470A1 (fr) 2022-10-31 2022-10-31 Procédé, dispositif et support d'enregistrement informatique de communication

Publications (1)

Publication Number Publication Date
WO2024092470A1 true WO2024092470A1 (fr) 2024-05-10

Family

ID=90929051

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2022/128807 WO2024092470A1 (fr) 2022-10-31 2022-10-31 Procédé, dispositif et support d'enregistrement informatique de communication

Country Status (1)

Country Link
WO (1) WO2024092470A1 (fr)

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20100061477A1 (en) * 2006-06-22 2010-03-11 Lg Electronics Inc. Data transfer method using phase-shift based precoding and transmitter implementing the same
CN114124176A (zh) * 2020-08-27 2022-03-01 华为技术有限公司 预编码方法及通信装置
WO2022067866A1 (fr) * 2020-10-03 2022-04-07 Qualcomm Incorporated Indication d'une matrice de précodage pour des répétitions de canal partagé de liaison montante physique

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20100061477A1 (en) * 2006-06-22 2010-03-11 Lg Electronics Inc. Data transfer method using phase-shift based precoding and transmitter implementing the same
CN114124176A (zh) * 2020-08-27 2022-03-01 华为技术有限公司 预编码方法及通信装置
WO2022067866A1 (fr) * 2020-10-03 2022-04-07 Qualcomm Incorporated Indication d'une matrice de précodage pour des répétitions de canal partagé de liaison montante physique

Similar Documents

Publication Publication Date Title
US10511365B2 (en) Linear combination codebook for CSI reporting in advanced wireless communication systems
US10659118B2 (en) Method and apparatus for explicit CSI reporting in advanced wireless communication systems
CN108023624B (zh) 一种预编码矩阵指示方法、装置和系统
JP7097385B2 (ja) 送信ビーム情報を取得する方法と装置、および送信ビーム情報をフィードバックする方法と装置
JP6325652B2 (ja) 無線通信システムにおいてチャネル状態情報送信方法及び装置
JP2019525637A (ja) プリコーディング行列決定方法およびプリコーディング行列決定装置
WO2021217328A1 (fr) Techniques de rapport csi pour stations de base en duplex intégral à panneaux multiples
US20180367193A1 (en) Determination of sub-band allocation parameters for wireless networks
JP2022529124A (ja) 通信効率の向上
US20180367196A1 (en) Efficient techniques to signal codebook subset restriction bit map in wireless communication systems
KR20100133883A (ko) 다중 안테나 시스템에서의 코드북 설계 방법 및 데이터 전송 방법
US10461823B2 (en) Aperture constraint for new radio uplink multiple-input multiple-output
WO2022027625A1 (fr) Précodage dans le domaine fréquentiel pour réciprocité fdd
WO2024092470A1 (fr) Procédé, dispositif et support d'enregistrement informatique de communication
WO2023123379A1 (fr) Procédés, dispositifs et support lisible par ordinateur destinés à des communications
WO2023039713A1 (fr) Systèmes, procédés et supports non transitoires lisibles par un processeur pour déterminer des informations de précodage pour des transmissions en liaison montante
WO2023184555A1 (fr) Procédés, dispositifs, et support lisible par ordinateur pour des communications
WO2022205066A1 (fr) Procédés, dispositifs et supports de stockage informatiques de communication
CN117461342A (zh) 用于通信的方法、设备和计算机存储介质
WO2023206284A1 (fr) Procédés, dispositifs, et support lisible par ordinateur pour des communications
WO2023206291A1 (fr) Procédés, dispositifs, et support lisible par ordinateur pour communication
WO2024152370A1 (fr) Procédé, dispositif et support de stockage informatique de communication
WO2024031580A1 (fr) Procédés, dispositifs et support lisible par ordinateur pour des communications
WO2024152374A1 (fr) Procédé, dispositif et support de stockage informatique de communication
WO2024130611A1 (fr) Procédé, dispositif et support de stockage informatique de communication

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 22963789

Country of ref document: EP

Kind code of ref document: A1