WO2021035385A1 - Utilisation de signaux de référence multiples dans une estimation de canal - Google Patents

Utilisation de signaux de référence multiples dans une estimation de canal Download PDF

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Publication number
WO2021035385A1
WO2021035385A1 PCT/CN2019/102178 CN2019102178W WO2021035385A1 WO 2021035385 A1 WO2021035385 A1 WO 2021035385A1 CN 2019102178 W CN2019102178 W CN 2019102178W WO 2021035385 A1 WO2021035385 A1 WO 2021035385A1
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WO
WIPO (PCT)
Prior art keywords
downlink reference
precoder
reference signals
channel
channel estimation
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PCT/CN2019/102178
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English (en)
Inventor
Chenxi Zhu
Bingchao LIU
Wei Ling
Lingling Xiao
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Lenovo (Beijing) Limited
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Application filed by Lenovo (Beijing) Limited filed Critical Lenovo (Beijing) Limited
Priority to PCT/CN2019/102178 priority Critical patent/WO2021035385A1/fr
Publication of WO2021035385A1 publication Critical patent/WO2021035385A1/fr

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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B7/00—Radio transmission systems, i.e. using radiation field
    • H04B7/02—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas
    • H04B7/04—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas
    • H04B7/0413—MIMO systems
    • H04B7/0456—Selection of precoding matrices or codebooks, e.g. using matrices antenna weighting
    • 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
    • H04L5/0048—Allocation of pilot signals, i.e. of signals known to the receiver
    • 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
    • H04L5/0091—Signaling for the administration of the divided path
    • 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

  • the subject matter disclosed herein relates generally to wireless communications and more particularly relates to using multiple downlink reference signals for channel estimation.
  • HARQ-ACK may represent collectively the Positive Acknowledge ( “ACK” ) and the Negative Acknowledge ( “NAK” ) .
  • ACK means that a TB is correctly received while NAK means a TB is erroneously received.
  • a downlink reference signal may be received.
  • the downlink reference signal may be used for channel estimation.
  • the method includes transmitting a plurality of downlink reference signals, wherein: the plurality of downlink reference signals is used for channel estimation for a channel; and the channel is from a set of common antenna ports used for transmissions to a user equipment, wherein the set of common antenna ports are from a single panel.
  • An apparatus for transmitting multiple downlink reference signals for channel estimation includes a transmitter that transmits a plurality of downlink reference signals, wherein: the plurality of downlink reference signals is used for channel estimation for a channel; and the channel is from a set of common antenna ports used for transmissions to a user equipment, wherein the set of common antenna ports are from a single panel.
  • a method for using multiple downlink reference signals for channel estimation includes receiving a plurality of downlink reference signals, wherein: the plurality of downlink reference signals is used for channel estimation for a channel; and the channel is from a set of common antenna ports used for transmissions to a user equipment, wherein the set of common antenna ports are from a single panel.
  • the method includes determining the channel estimation for the channel using the plurality of downlink reference signals.
  • An apparatus for using multiple downlink reference signals for channel estimation includes a receiver that receives a plurality of downlink reference signals, wherein: the plurality of downlink reference signals is used for channel estimation for a channel; and the channel is from a set of common antenna ports used for transmissions to a user equipment, wherein the set of common antenna ports are from a single panel.
  • the apparatus includes a processor that determines the channel estimation for the channel using the plurality of downlink reference signals.
  • Figure 1 is a schematic block diagram illustrating one embodiment of a wireless communication system for using multiple downlink reference signals for channel estimation
  • Figure 2 is a schematic block diagram illustrating one embodiment of an apparatus that may be used for using multiple downlink reference signals for channel estimation
  • Figure 3 is a schematic block diagram illustrating one embodiment of an apparatus that may be used for transmitting multiple downlink reference signals for channel estimation
  • Figure 4 is a schematic block diagram illustrating one embodiment of communications including multiple downlink reference signals for channel estimation
  • Figure 5 is a schematic flow chart diagram illustrating one embodiment of a method for transmitting multiple downlink reference signals for channel estimation.
  • Figure 6 is a schematic flow chart diagram illustrating one embodiment of a method for using multiple downlink reference signals for channel estimation.
  • embodiments may be embodied as a system, apparatus, method, or program product. Accordingly, embodiments may take the form of an entirely hardware embodiment, an entirely software embodiment (including firmware, resident software, micro-code, etc. ) or an embodiment combining software and hardware aspects that may all generally be referred to herein as a “circuit, ” “module” or “system. ” Furthermore, embodiments may take the form of a program product embodied in one or more computer readable storage devices storing machine readable code, computer readable code, and/or program code, referred hereafter as code. The storage devices may be tangible, non-transitory, and/or non-transmission. The storage devices may not embody signals. In a certain embodiment, the storage devices only employ signals for accessing code.
  • modules may be implemented as a hardware circuit comprising custom very-large-scale integration ( “VLSI” ) circuits or gate arrays, off-the-shelf semiconductors such as logic chips, transistors, or other discrete components.
  • VLSI very-large-scale integration
  • a module may also be implemented in programmable hardware devices such as field programmable gate arrays, programmable array logic, programmable logic devices or the like.
  • Modules may also be implemented in code and/or software for execution by various types of processors.
  • An identified module of code may, for instance, include one or more physical or logical blocks of executable code which may, for instance, be organized as an object, procedure, or function. Nevertheless, the executables of an identified module need not be physically located together, but may include disparate instructions stored in different locations which, when joined logically together, include the module and achieve the stated purpose for the module.
  • a module of code may be a single instruction, or many instructions, and may even be distributed over several different code segments, among different programs, and across several memory devices.
  • operational data may be identified and illustrated herein within modules, and may be embodied in any suitable form and organized within any suitable type of data structure. The operational data may be collected as a single data set, or may be distributed over different locations including over different computer readable storage devices.
  • the software portions are stored on one or more computer readable storage devices.
  • the computer readable medium may be a computer readable storage medium.
  • the computer readable storage medium may be a storage device storing the code.
  • the storage device may be, for example, but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, holographic, micromechanical, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing.
  • a storage device More specific examples (a non-exhaustive list) of the storage device would include the following: 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) , a portable compact disc read-only memory (CD-ROM” ) , an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.
  • a computer readable storage medium may be any tangible medium that can contain, or store a program for use by or in connection with an instruction execution system, apparatus, or device.
  • Code for carrying out operations for embodiments may be any number of lines and may be written in any combination of one or more programming languages including an object oriented programming language such as Python, Ruby, Java, Smalltalk, C++, or the like, and conventional procedural programming languages, such as the "C" programming language, or the like, and/or machine languages such as assembly languages.
  • the code may execute entirely on the user's computer, partly on the user's computer, as a stand-alone software package, partly on the user's computer and partly on a remote computer or entirely on the remote computer or server.
  • the remote computer may be connected to the user's computer through any type of network, including a local area network ( “LAN” ) or a wide area network ( “WAN” ) , or the connection may be made to an external computer (for example, through the Internet using an Internet Service Provider) .
  • LAN local area network
  • WAN wide area network
  • the code may also be stored in a storage device that can direct a computer, other programmable data processing apparatus, or other devices to function in a particular manner, such that the instructions stored in the storage device produce an article of manufacture including instructions which implement the function/act specified in the schematic flowchart diagrams and/or schematic block diagrams block or blocks.
  • the code may also be loaded onto a computer, other programmable data processing apparatus, or other devices to cause a series of operational steps to be performed on the computer, other programmable apparatus or other devices to produce a computer implemented process such that the code which execute on the computer or other programmable apparatus provide processes for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks.
  • each block in the schematic flowchart diagrams and/or schematic block diagrams may represent a module, segment, or portion of code, which includes one or more executable instructions of the code for implementing the specified logical function (s) .
  • Figure 1 depicts an embodiment of a wireless communication system 100 for using multiple downlink reference signals for channel estimation.
  • the wireless communication system 100 includes remote units 102 and network units 104. Even though a specific number of remote units 102 and network units 104 are depicted in Figure 1, one of skill in the art will recognize that any number of remote units 102 and network units 104 may be included in the wireless communication system 100.
  • the remote units 102 may include computing devices, such as desktop computers, laptop computers, personal digital assistants ( “PDAs” ) , tablet computers, smart phones, smart televisions (e.g., televisions connected to the Internet) , set-top boxes, game consoles, security systems (including security cameras) , vehicle on-board computers, network devices (e.g., routers, switches, modems) , IoT devices, or the like.
  • the remote units 102 include wearable devices, such as smart watches, fitness bands, optical head-mounted displays, or the like.
  • the remote units 102 may be referred to as subscriber units, mobiles, mobile stations, users, terminals, mobile terminals, fixed terminals, subscriber stations, UE, user terminals, a device, or by other terminology used in the art.
  • the remote units 102 may communicate directly with one or more of the network units 104 via UL communication signals and/or the remote units 102 may communicate directly with other remote units 102 via sidelink communication.
  • the network units 104 may be distributed over a geographic region.
  • a network unit 104 may also be referred to as an access point, an access terminal, a base, a base station, a Node-B, an eNB, a gNB, a Home Node-B, a RAN, a relay node, a device, a network device, an IAB node, a donor IAB node, or by any other terminology used in the art.
  • the network units 104 are generally part of a radio access network that includes one or more controllers communicably coupled to one or more corresponding network units 104.
  • the radio access network is generally communicably coupled to one or more core networks, which may be coupled to other networks, like the Internet and public switched telephone networks, among other networks.
  • core networks like the Internet and public switched telephone networks, among other networks.
  • the wireless communication system 100 is compliant with the 5G or NG (Next Generation) standard of the 3GPP protocol, wherein the network unit 104 transmits using NG RAN technology. More generally, however, the wireless communication system 100 may implement some other open or proprietary communication protocol, for example, WiMAX, among other protocols.
  • the present disclosure is not intended to be limited to the implementation of any particular wireless communication system architecture or protocol.
  • the network units 104 may serve a number of remote units 102 within a serving area, for example, a cell or a cell sector via a wireless communication link.
  • the network units 104 transmit DL communication signals to serve the remote units 102 in the time, frequency, and/or spatial domain.
  • a network unit 104 may transmit a plurality of downlink reference signals, wherein: the plurality of downlink reference signals is used for channel estimation for a channel; and the channel is from a set of common antenna ports used for transmissions to a user equipment, wherein the set of common antenna ports are from a single panel. Accordingly, a network unit 104 may be used for transmitting multiple downlink reference signals for channel estimation.
  • a remote unit 102 may receive a plurality of downlink reference signals, wherein: the plurality of downlink reference signals is used for channel estimation for a channel; and the channel is from a set of common antenna ports used for transmissions to a user equipment, wherein the set of common antenna ports are from a single panel.
  • the remote unit 102 may determine the channel estimation for the channel using the plurality of downlink reference signals. Accordingly, a remote unit 102 may be used for using multiple downlink reference signals for channel estimation.
  • Figure 2 depicts one embodiment of an apparatus 200 that may be used for using multiple downlink reference signals for channel estimation.
  • the apparatus 200 includes one embodiment of the remote unit 102.
  • the remote unit 102 may include a processor 202, a memory 204, an input device 206, a display 208, a transmitter 210, and a receiver 212.
  • the input device 206 and the display 208 are combined into a single device, such as a touchscreen.
  • the remote unit 102 may not include any input device 206 and/or display 208.
  • the remote unit 102 may include one or more of the processor 202, the memory 204, the transmitter 210, and the receiver 212, and may not include the input device 206 and/or the display 208.
  • the processor 202 may include any known controller capable of executing computer-readable instructions and/or capable of performing logical operations.
  • the processor 202 may be a microcontroller, a microprocessor, a central processing unit ( “CPU” ) , a graphics processing unit ( “GPU” ) , an auxiliary processing unit, a field programmable gate array ( “FPGA” ) , or similar programmable controller.
  • the processor 202 executes instructions stored in the memory 204 to perform the methods and routines described herein.
  • the processor 202 determines a channel estimation for a channel using a plurality of downlink reference signals.
  • the processor 202 is communicatively coupled to the memory 204, the input device 206, the display 208, the transmitter 210, and the receiver 212.
  • the memory 204 in one embodiment, is a computer readable storage medium.
  • the memory 204 includes volatile computer storage media.
  • the memory 204 may include a RAM, including dynamic RAM ( “DRAM” ) , synchronous dynamic RAM ( “SDRAM” ) , and/or static RAM ( “SRAM” ) .
  • the memory 204 includes non-volatile computer storage media.
  • the memory 204 may include a hard disk drive, a flash memory, or any other suitable non-volatile computer storage device.
  • the memory 204 includes both volatile and non-volatile computer storage media.
  • the memory 204 also stores program code and related data, such as an operating system or other controller algorithms operating on the remote unit 102.
  • the input device 206 may include any known computer input device including a touch panel, a button, a keyboard, a stylus, a microphone, or the like.
  • the input device 206 may be integrated with the display 208, for example, as a touchscreen or similar touch-sensitive display.
  • the input device 206 includes a touchscreen such that text may be input using a virtual keyboard displayed on the touchscreen and/or by handwriting on the touchscreen.
  • the input device 206 includes two or more different devices, such as a keyboard and a touch panel.
  • the display 208 may include any known electronically controllable display or display device.
  • the display 208 may be designed to output visual, audible, and/or haptic signals.
  • the display 208 includes an electronic display capable of outputting visual data to a user.
  • the display 208 may include, but is not limited to, an LCD display, an LED display, an OLED display, a projector, or similar display device capable of outputting images, text, or the like to a user.
  • the display 208 may include a wearable display such as a smart watch, smart glasses, a heads-up display, or the like.
  • the display 208 may be a component of a smart phone, a personal digital assistant, a television, a table computer, a notebook (laptop) computer, a personal computer, a vehicle dashboard, or the like.
  • the display 208 includes one or more speakers for producing sound.
  • the display 208 may produce an audible alert or notification (e.g., a beep or chime) .
  • the display 208 includes one or more haptic devices for producing vibrations, motion, or other haptic feedback.
  • all or portions of the display 208 may be integrated with the input device 206.
  • the input device 206 and display 208 may form a touchscreen or similar touch-sensitive display.
  • the display 208 may be located near the input device 206.
  • the transmitter 210 is used to provide UL communication signals to the network unit 104 and the receiver 212 is used to receive DL communication signals from the network unit 104.
  • the receiver 212 receives a plurality of downlink reference signals, wherein: the plurality of downlink reference signals is used for channel estimation for a channel; and the channel is from a set of common antenna ports used for transmissions to a user equipment, wherein the set of common antenna ports are from a single panel.
  • the remote unit 102 may have any suitable number of transmitters 210 and receivers 212.
  • the transmitter 210 and the receiver 212 may be any suitable type of transmitters and receivers.
  • the transmitter 210 and the receiver 212 may be part of a transceiver.
  • Figure 3 depicts one embodiment of an apparatus 300 that may be used for transmitting multiple downlink reference signals for channel estimation.
  • the apparatus 300 includes one embodiment of the network unit 104.
  • the network unit 104 may include a processor 302, a memory 304, an input device 306, a display 308, a transmitter 310, and a receiver 312.
  • the processor 302, the memory 304, the input device 306, the display 308, the transmitter 310, and the receiver 312 may be substantially similar to the processor 202, the memory 204, the input device 206, the display 208, the transmitter 210, and the receiver 212 of the remote unit 102, respectively.
  • the transmitter 310 transmits a plurality of downlink reference signals, wherein: the plurality of downlink reference signals is used for channel estimation for a channel; and the channel is from a set of common antenna ports used for transmissions to a user equipment, wherein the set of common antenna ports are from a single panel.
  • the network unit 104 may have any suitable number of transmitters 310 and receivers 312.
  • the transmitter 310 and the receiver 312 may be any suitable type of transmitters and receivers.
  • the transmitter 310 and the receiver 312 may be part of a transceiver.
  • channel estimation and/or CSI feedback may be an important part of a MIMO scheme.
  • channel estimation for DL may be determined using SSB and/or CSI-RS.
  • CSI feedback may be based on a channel measurement conducted on SSB and/or CSI-RS.
  • SSB may be transmitted from a single port and a UE may only conduct an L1-RSRP measurement from the SSB.
  • CSI-RS may be transmitted for channel measurement or interference measurement with zero power (e.g., CSI-IM) or non-zero power (e.g., NZP-CSI-RS) .
  • all SSBs and non-zero power CSI-RSs may be transmitted by a gNB with the same set of antenna elements, sometimes with zero power from some of the antennas, but they are unrelated from a UE point of view.
  • SSBs may be single port signals used for synchronization and MIB information acquisition by UEs.
  • a gNB may transmit up to 64 SSB resource sets and each set may contain 64 SSBs.
  • different CSI-RS resources may be estimated separately.
  • no correlation may be assumed between different SSBs, between SSB and CSI-RS, and/or between CSI-RS resources, even if they are transmitted from the same set of antenna elements. This may limit an accuracy of a channel estimation and/or a CSI feedback quality.
  • SSBs and CSI-RS resources or other DL RSs transmitted from a same set of TX antenna ports jointly for DL channel estimation. Accordingly, many signals (e.g., SSB and/or CSI-RS) may be used together for joint DL channel estimation to improve a channel estimation quality. Moreover, CSI information may be computed based on the estimated channel.
  • SSBs are single port signals used for synchronization and MIB information acquisition by UEs.
  • a gNB may transmit up to 64 SSB resource sets and each set may contain 64 SSBs. The total number of SSBs may be up to 64.
  • a UE may only measure L1-RSRP based on an SSB and may provide the measurement results to a gNB in its CSI feedback.
  • a UE may be configured with a list of SSBs for CSI measurement by RRC in an SSB-ToMeasure IE.
  • the SSB-ToMeasure IE may be used to configure a pattern of SSBs. Table 1 shows one embodiment of an SSB-ToMeasure IE and Table 2 shows one embodiment of field descriptions corresponding to the SSB-ToMeasure IE.
  • CSI-RS resources may be used for certain types of CSI feedback.
  • a CSI report may be configured by RRC using a CSI-ReportConfig IE.
  • the CSI-ReportConfig IE may define resources used for channel measurement and interference measurement, a report CSI quantity (e.g., RSRP, SSB index, CRI, RI, PMI, CQI, LI) , a reporting granularity, and/or a reporting type (e.g., periodic, semi-persistent, aperiodic) .
  • a UE measures CSI-RS resources configured by RRC in a CSI-MeasConfig IE.
  • a CSI-MeasConfig IE may be used to configure CSI-RS (e.g., reference signals) belonging to a serving cell in which the CSI-MeasConfig IE is included, channel state information reports to be transmitted on PUCCH on the serving cell in which CSI-MeasConfig IE is included, and/or channel state information reports on PUSCH triggered by DCI received on the serving cell in which CSI-MeasConfig IE is included. See TS 38.214 [19], clause 5.2, for example. Table 3 shows one embodiment of a CSI-MeasConfig IE and Table 4 shows one embodiment of field descriptions corresponding to the CSI-MeasConfig IE.
  • CSI-RS e.g., reference signals
  • a CSI report configuration in RRC may be defined by a CSI-ReportConfig IE.
  • the CSI-ReportConfig IE may be used to configure a periodic or semi-persistent report sent on PUCCH on a cell in which the CSI-ReportConfig IE is included, or to configure a semi-persistent or aperiodic report sent on PUSCH triggered by DCI received on the cell in which the CSI-ReportConfig IE is included (e.g., the cell on which the report is sent may be determined by received DCI) . See TS 38.214 [19] , clause 5.2.1, for example. Table 5 shows one embodiment of a CSI-ReportConfig IE and Table 6 shows one embodiment of field descriptions corresponding to the CSI-ReportConfig IE.
  • a UE may only use SSB or CSI-RS resources that are configured. It should be noted that for CSI feedback based on CSI-RS, although there may be two non-zero-power CSI-RS resources, they are used for different purposes including channel measurement and interference measurement. Moreover, in some embodiments, channel estimation for a source gNB (e.g., CSI-RS for channel measurement) and an interfering gNB (e.g., NZP-CSI-RS for interference measurement) may be done separately, and may be used together only when calculating PMI, RI, and/or CQI.
  • CSI-RS for channel measurement
  • an interfering gNB e.g., NZP-CSI-RS for interference measurement
  • DL codebooks for PMI feedback in CSI may be defined in section 5.2.2.2 of TS 38.214. Certain embodiments of codebooks are shown in Tables 7-10.
  • Table 7 Codebooks for 1-layer and 2-layer CSI Reporting Using Antenna Ports 3000 to 3001
  • FIG. 4 is a schematic block diagram illustrating one embodiment of communications 400 including multiple downlink reference signals for channel estimation.
  • the communications 400 include communications between antenna ports 402 (e.g., a set of antenna ports from a single panel of the network unit 104, common antenna ports) and a UE 404 (e.g., a remote unit 102) .
  • each communication of the communications 400 may include one or more messages.
  • a first communication 406 is transmitted from the antenna ports 402 to the UE 404.
  • the first communication 406 may include multiple downlink reference signals that may all be used for channel estimate for a channel from the antenna ports 402 from a single panel.
  • a second communication 408 is transmitted from one or more of the antenna ports 402 to the UE 404.
  • the second communication 408 includes information indicating precoders corresponding to the multiple downlink reference signals. As may be appreciated, the second communication 408 may occur before, after, or during the first communication 406.
  • the second communication 408 occurs, then the first communication 406 occurs; in other embodiments, the first communication 406 occurs, then the second communication 408 occurs; while in yet other embodiments, the first communication 406 and the second communication 408 overlap in time.
  • the UE 404 determines 410 the channel estimation for the channel using the multiple downlink reference signals.
  • a third communication 412 is transmitted from the UE 404 to the network unit 104 that includes the antenna ports 402. The third communication 412 may include CSI feedback.
  • a set of antenna ports from which SSBs and CSI-RSs are transmitted may be defined.
  • the set of antenna ports may be physical antenna elements and/or logical antenna ports transmitted from a set of antenna elements (e.g., possibly with a fixed beamforming vector) .
  • channel estimation from the set of antenna ports may be conducted through different signals (e.g., including SSB and/or CSI-RS) with precoders known to UEs and used for CSI feedback.
  • a gNB used to transmit the SSBs from antenna ports may provide corresponding precoders that are used to the UE.
  • precoders that are used may be from a DL codebook defined in TS 38.214, or they may be from another DL codebook (or otherwise determined) .
  • SSB precoder information may be provided to UEs in one or more RRC messages.
  • different SSB resources may use different precoders.
  • a set of antenna ports with K ports P 0 [p 0 , p 1 , ...p K-1 ] , and SSB resource i is transmitted from a set of antenna ports with a precoder W i SSB .
  • W i SSB is a vector of length K.
  • antenna ports of a CSI-RS resource may be defined in association with other antenna ports using precoder information that is provided to the UE in one or more RRC messages.
  • a received signal vector of length M at UE is given by:
  • j 0...J-1, where is the jth CSI-RS sequence in a corresponding RE with a TX power incorporated. is the receiver noise when receiving the jth CSI-RS signal.
  • a CSI-RS resource may also be defined by a precoder matrix with respect to another CSI-RS resource (other than the original K ports) .
  • CSI-RS resource l is defined with respect to CSI-RS resource n with precoder and is the precoder of CSI-RS resource n based on ports P 0
  • the precoder of CSI-RS resource l with respect to ports P 0 is:
  • CSI-RS resource l may be a 2 port CSI-RS resource based on a 4 port CSI-RS resource n with a 4 port 2-layer precoder
  • a receiver may estimate a channel matrix H from I SSB signals and J CSI-RS resources jointly as follows:
  • a channel matrix H may be estimated by a ZF estimator as follows:
  • a channel matrix H may be estimated by an MMSE estimator as follows: where is the SNR of the received signals.
  • a single port channel for an ith SSB may be derived as: and the channel for the jth CSI-RS resource can be derived as:
  • a CSI-RS resource p if a CSI-RS resource p is not transmitted, but its precoder is known, its channel may be derived as based on an estimated channel H from ports P 0 .
  • using multiple downlink reference signals for channel estimation may not affect the usage of SSB for synchronization and/or cell detection.
  • the UE may estimate an ith SSB signal as a single port channel. The UE may re-estimate a channel after it has acquired more reference signals with precoder information, as described herein.
  • the methods described herein do not prevent a UE from using individual CSI-RS resources for channel estimation.
  • an SSB or CSI-RS channel may be estimated individually or jointly with other signals, depending on an availability of precoder information and depending on whether the set of signals fall into a coherent time corresponding to the channel.
  • a coherent time may be a time in which a channel does not change significantly. Outside of the coherent time, a channel may change too much to make a joint estimation using multiple signals. It should be noted that only signals within a coherent time for a corresponding channel may be used together for joint estimation.
  • CSI feedback e.g., CRI, RI, PMI, CQI, LI
  • the methods described herein may be used to increase channel estimation accuracy.
  • Figure 5 is a schematic flow chart diagram illustrating one embodiment of a method 500 for transmitting multiple downlink reference signals for channel estimation.
  • the method 500 is performed by an apparatus, such as the network unit 104.
  • the method 500 may be performed by a processor executing program code, for example, a microcontroller, a microprocessor, a CPU, a GPU, an auxiliary processing unit, a FPGA, or the like.
  • the method 500 may include transmitting 502 a plurality of downlink reference signals, wherein: the plurality of downlink reference signals is used for channel estimation for a channel; and the channel is from a set of common antenna ports used for transmissions to a user equipment, wherein the set of common antenna ports are from a single panel.
  • the method 500 further comprises transmitting information indicating a first precoder for a first downlink reference signal of the plurality of downlink reference signals. In some embodiments, the method 500 further comprises transmitting information indicating a second precoder for a second downlink reference signal of the plurality of downlink reference signals. In some embodiments, transmitting information indicating the first precoder and/or the second precoder comprises transmitting a precoding vector (w) or transmitting an index of a codeword in a codebook. In various embodiments, the first precoder is selected from a predefined codebook or the second precoder is selected from the predefined codebook.
  • first information corresponding to the first precoder is transmitted in a radio resource control message
  • second information corresponding to the second precoder is transmitted in the radio resource control message, or a combination thereof.
  • the plurality of downlink reference signals comprises synchronization signals, broadcast channels, channel state information reference signals, or some combination thereof.
  • Figure 6 is a schematic flow chart diagram illustrating one embodiment of a method 600 for using multiple downlink reference signals for channel estimation.
  • the method 600 is performed by an apparatus, such as the remote unit 102.
  • the method 600 may be performed by a processor executing program code, for example, a microcontroller, a microprocessor, a CPU, a GPU, an auxiliary processing unit, a FPGA, or the like.
  • the method 600 may include receiving 602 a plurality of downlink reference signals, wherein: the plurality of downlink reference signals is used for channel estimation for a channel; and the channel is from a set of common antenna ports used for transmissions to a user equipment, wherein the set of common antenna ports are from a single panel.
  • the method 600 includes determining 604 the channel estimation for the channel using the plurality of downlink reference signals.
  • the method 600 further comprises receiving information indicating a first precoder for a first downlink reference signal of the plurality of downlink reference signals. In some embodiments, the method 600 further comprises receiving information indicating a second precoder for a second downlink reference signal of the plurality of downlink reference signals. In some embodiments, transmitting information indicating the first precoder and/or the second precoder comprises transmitting a precoding vector (w) or transmitting an index of a codeword in a codebook. In various embodiments, the first precoder is selected from a predefined codebook or the second precoder is selected from the predefined codebook.
  • first information corresponding to the first precoder is received in a radio resource control message
  • second information corresponding to the second precoder is received in the radio resource control message, or a combination thereof.
  • determining the channel estimation comprises using the first precoder, the first downlink reference signal, the second precoder, and the second downlink reference signal to determine the channel estimation.
  • the plurality of downlink reference signals comprises synchronization signals, broadcast channels, channel state information reference signals, or some combination thereof.
  • the channel estimation is used to derive channel state information.
  • a method comprises: transmitting a plurality of downlink reference signals, wherein: the plurality of downlink reference signals is used for channel estimation for a channel; and the channel is from a set of common antenna ports used for transmissions to a user equipment, wherein the set of common antenna ports are from a single panel.
  • the method further comprises transmitting information indicating a first precoder for a first downlink reference signal of the plurality of downlink reference signals.
  • the method further comprises transmitting information indicating a second precoder for a second downlink reference signal of the plurality of downlink reference signals.
  • the first precoder is selected from a predefined codebook or the second precoder is selected from the predefined codebook.
  • first information corresponding to the first precoder is transmitted in a radio resource control message
  • second information corresponding to the second precoder is transmitted in the radio resource control message, or a combination thereof.
  • the plurality of downlink reference signals comprises synchronization signals, broadcast channels, channel state information reference signals, or some combination thereof.
  • an apparatus comprises: a transmitter that transmits a plurality of downlink reference signals, wherein: the plurality of downlink reference signals is used for channel estimation for a channel; and the channel is from a set of common antenna ports used for transmissions to a user equipment, wherein the set of common antenna ports are from a single panel.
  • the transmitter transmits information indicating a first precoder for a first downlink reference signal of the plurality of downlink reference signals.
  • the transmitter transmits information indicating a second precoder for a second downlink reference signal of the plurality of downlink reference signals.
  • the first precoder is selected from a predefined codebook or the second precoder is selected from the predefined codebook.
  • first information corresponding to the first precoder is transmitted in a radio resource control message
  • second information corresponding to the second precoder is transmitted in the radio resource control message, or a combination thereof.
  • the plurality of downlink reference signals comprises synchronization signals, broadcast channels, channel state information reference signals, or some combination thereof.
  • a method comprises: receiving a plurality of downlink reference signals, wherein: the plurality of downlink reference signals is used for channel estimation for a channel; and the channel is from a set of common antenna ports used for transmissions to a user equipment, wherein the set of common antenna ports are from a single panel; and determining the channel estimation for the channel using the plurality of downlink reference signals.
  • the method further comprises receiving information indicating a first precoder for a first downlink reference signal of the plurality of downlink reference signals.
  • the method further comprises receiving information indicating a second precoder for a second downlink reference signal of the plurality of downlink reference signals.
  • the first precoder is selected from a predefined codebook or the second precoder is selected from the predefined codebook.
  • first information corresponding to the first precoder is received in a radio resource control message
  • second information corresponding to the second precoder is received in the radio resource control message, or a combination thereof.
  • determining the channel estimation comprises using the first precoder, the first downlink reference signal, the second precoder, and the second downlink reference signal to determine the channel estimation.
  • the plurality of downlink reference signals comprises synchronization signals, broadcast channels, channel state information reference signals, or some combination thereof.
  • the channel estimation is used to derive channel state information.
  • an apparatus comprises: a receiver that receives a plurality of downlink reference signals, wherein: the plurality of downlink reference signals is used for channel estimation for a channel; and the channel is from a set of common antenna ports used for transmissions to a user equipment, wherein the set of common antenna ports are from a single panel; and a processor that determines the channel estimation for the channel using the plurality of downlink reference signals.
  • the receiver receives information indicating a first precoder for a first downlink reference signal of the plurality of downlink reference signals.
  • the receiver receives information indicating a second precoder for a second downlink reference signal of the plurality of downlink reference signals.
  • the first precoder is selected from a predefined codebook or the second precoder is selected from the predefined codebook.
  • first information corresponding to the first precoder is received in a radio resource control message
  • second information corresponding to the second precoder is received in the radio resource control message, or a combination thereof.
  • the processor determining the channel estimation comprises the processor using the first precoder, the first downlink reference signal, the second precoder, and the second downlink reference signal to determine the channel estimation.
  • the plurality of downlink reference signals comprises synchronization signals, broadcast channels, channel state information reference signals, or some combination thereof.
  • the channel estimation is used to derive channel state information.

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

Abstract

L'invention concerne des appareils, des procédés et des systèmes de transmission de signaux de référence de liaison descendante multiples pour une estimation de canal. Un procédé (500) selon l'invention consiste à transmettre (502) une pluralité de signaux de référence de liaison descendante. La pluralité de signaux de référence de liaison descendante est utilisée pour une estimation de canal pour un canal donné. Le canal provient d'un ensemble de ports d'antenne communs utilisés pour des transmissions vers un équipement utilisateur. L'ensemble de ports d'antenne communs provient d'un panneau unique.
PCT/CN2019/102178 2019-08-23 2019-08-23 Utilisation de signaux de référence multiples dans une estimation de canal WO2021035385A1 (fr)

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2024067251A1 (fr) * 2022-09-30 2024-04-04 华为技术有限公司 Procédé de communication et dispositif associé

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Publication number Priority date Publication date Assignee Title
US20140192768A1 (en) * 2013-01-04 2014-07-10 Electronics And Telecommunications Research Institute Method for transmitting signal using multiple antennas
CN108023624A (zh) * 2016-11-03 2018-05-11 华为技术有限公司 一种预编码矩阵指示方法、装置和系统
WO2018128498A1 (fr) * 2017-01-09 2018-07-12 엘지전자(주) Procédé de notification d'informations d'état de canal dans un système de communications sans fil et dispositif associé
CN109391296A (zh) * 2017-08-11 2019-02-26 索尼公司 用于无线通信的电子设备、方法和介质

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Publication number Priority date Publication date Assignee Title
US20140192768A1 (en) * 2013-01-04 2014-07-10 Electronics And Telecommunications Research Institute Method for transmitting signal using multiple antennas
CN108023624A (zh) * 2016-11-03 2018-05-11 华为技术有限公司 一种预编码矩阵指示方法、装置和系统
WO2018128498A1 (fr) * 2017-01-09 2018-07-12 엘지전자(주) Procédé de notification d'informations d'état de canal dans un système de communications sans fil et dispositif associé
CN109391296A (zh) * 2017-08-11 2019-02-26 索尼公司 用于无线通信的电子设备、方法和介质

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2024067251A1 (fr) * 2022-09-30 2024-04-04 华为技术有限公司 Procédé de communication et dispositif associé

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