WO2018044849A1 - Procédés de codage de longueur de bloc finie dans des systèmes de communication sans fil - Google Patents

Procédés de codage de longueur de bloc finie dans des systèmes de communication sans fil Download PDF

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Publication number
WO2018044849A1
WO2018044849A1 PCT/US2017/049039 US2017049039W WO2018044849A1 WO 2018044849 A1 WO2018044849 A1 WO 2018044849A1 US 2017049039 W US2017049039 W US 2017049039W WO 2018044849 A1 WO2018044849 A1 WO 2018044849A1
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WIPO (PCT)
Prior art keywords
wtru
cqi
blocklength
mcs
codeword
Prior art date
Application number
PCT/US2017/049039
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English (en)
Inventor
Liangping Ma
Cenk Sahin
Lingjia Liu
Erik PERRINS
Byung K. Yi
Original Assignee
Idac Holdings, Inc.
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 Idac Holdings, Inc. filed Critical Idac Holdings, Inc.
Publication of WO2018044849A1 publication Critical patent/WO2018044849A1/fr

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Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L1/00—Arrangements for detecting or preventing errors in the information received
    • H04L1/0001—Systems modifying transmission characteristics according to link quality, e.g. power backoff
    • H04L1/0023—Systems modifying transmission characteristics according to link quality, e.g. power backoff characterised by the signalling
    • H04L1/0026—Transmission of channel quality indication
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L1/00—Arrangements for detecting or preventing errors in the information received
    • H04L1/0001—Systems modifying transmission characteristics according to link quality, e.g. power backoff
    • H04L1/0009—Systems modifying transmission characteristics according to link quality, e.g. power backoff by adapting the channel coding
    • H04L1/0011—Systems modifying transmission characteristics according to link quality, e.g. power backoff by adapting the channel coding applied to payload information

Definitions

  • CQI channel quality indicator
  • MCS modulation and coding scheme
  • a method implemented in a wireless transmit/receive unit includes receiving control information, including a codeword blocklength and a target BLER parameter for the DL transmission, measuring channel state information (CSI), determining a WTRU-based channel quality indicator (CQI) based on the measured CSI, the codeword blocklength, and the target BLER parameter, and transmitting the WTRU-based CQI to a base station.
  • control information including a codeword blocklength and a target BLER parameter for the DL transmission, measuring channel state information (CSI), determining a WTRU-based channel quality indicator (CQI) based on the measured CSI, the codeword blocklength, and the target BLER parameter, and transmitting the WTRU-based CQI to a base station.
  • CSI channel state information
  • CQI channel quality indicator
  • the method may further include receiving a network-based CQI for the DL transmission, the network-based CQI being derived from the WTRU-based CQI, determining an MCS based on the network-based CQI, and receiving the DL transmission using the determined MCS.
  • a WTRU includes a receiver configured to receive control information, including a codeword blocklength and a target block error rate (BLER) parameter for a downlink (DL) transmission, at least one processor configured to measure channel state information (CSI) and determine a WTRU- based channel quality indicator (CQI) based on the measured CSI, the codeword blocklength, and the target BLER parameter, and a transmitter configured to transmit the WTRU-based CQI to a base station.
  • control information including a codeword blocklength and a target block error rate (BLER) parameter for a downlink (DL) transmission
  • BLER target block error rate
  • CQI channel quality indicator
  • the receiver may be further configured to receive a network-based CQI for the DL transmission, the network-based CQI being derived from the WTRU-based CQI.
  • the at least one processor may be further configured to determine an MCS based on the network-based CQI.
  • the receiver may be further configured to receive the DL transmission using the determined MCS.
  • FIG. 1A is a system diagram illustrating an example communications system in which one or more disclosed embodiments may be implemented
  • FIG. IB is a system diagram illustrating an example wireless transmit/receive unit (WTRU) that may be used within the communications system illustrated in FIG. 1 A according to an embodiment;
  • WTRU wireless transmit/receive unit
  • FIG. 1C is a system diagram illustrating an example radio access network
  • RAN and an example core network (CN) that may be used within the communications system illustrated in FIG. 1 A according to an embodiment
  • FIG. ID is a system diagram illustrating a further example RAN and a further example CN that may be used within the communications system illustrated in FIG. 1 A according to an embodiment
  • FIG. 2A is a graph illustrating an effect of blocklength on the block error rate (BER) performance for binary phase shift keying (BPSK) and low-density parity- check (LDPC) according to one or more embodiments;
  • BER block error rate
  • FIG. 2B is a graph illustrating an effect of blocklength on the frame error rate (FER) performance for BPSK and LDPC according to one or more embodiments;
  • FIG. 3 is a graph illustrating of the maximum rate of an additive white
  • FIG. 4 is a graph illustrating the actual coding rate as a function of the blocklength for different modulation and coding scheme (MCS) values (IMCS) in LTE/LTE-A;
  • MCS modulation and coding scheme
  • FIG. 5 A and 5B illustrate a least square method for building an empirical curve that describes the code rate as a function of the blocklength for a given BLER and modulation
  • FIG. 6 is a timing diagram where the e B sends the WTRU information about the size of the new data and waits for the blocklength-specific CQI before data transmission;
  • FIG. 7 is a timing diagram where the eNB sends the WTRU information about resource allocation and waits for the blocklength-specific channel quality indicator (CQI) before data transmission;
  • CQI blocklength-specific channel quality indicator
  • FIG. 8 is a timing diagram where the WTRU feeds back the CQI values for different blocklength ranges proactively so that the additional delay can be eliminated according to one or more embodiments;
  • FIG. 9 is a graph that shows an example of a receiver selecting / parallel channels and reporting channel dispersion parameters of each selected channel according to one or more embodiments;
  • FIG. 10 illustrates a block diagram showing an information exchange between the transmitter and receiver in a wireless communications system according to one or more embodiments
  • FIG. 11 illustrates a block diagram showing an information exchange in a wireless communications system according to one or more embodiments
  • FIG. 12 illustrates a flow diagram of a CQI feedback procedure implemented according to one or more embodiments
  • FIG. 13 is a graph illustrating an average hybrid automatic repeat request
  • HARQ block error rate
  • FIG. 14 is a timing diagram that shows CQI feedback for multiple BLERs for transmitting multiple transport blocks in one transmitting time interval (TTI) in a single layer/stream, with multiple CQFs for each target BLER according to one or more embodiments; and [0027] FIG. 15 is a timing diagram that shows feeding back blocklength-specific
  • CQI's for different target BLER's for transmitting multiple transport blocks in one TTI in one layer/stream according to one or more embodiments.
  • FIG. 1A is a diagram illustrating an example communications system 100 in which one or more disclosed embodiments may be implemented.
  • the communications system 100 may be a multiple access system that provides content, such as voice, data, video, messaging, broadcast, etc., to multiple wireless users.
  • the communications system 100 may enable multiple wireless users to access such content through the sharing of system resources, including wireless bandwidth.
  • the communications systems 100 may employ one or more channel access methods, such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal FDMA (OFDMA), single-carrier FDMA (SC- FDMA), zero-tail unique-word discrete Fourier transform Spread OFDM (ZT UW DTS-s OFDM), unique word OFDM (UW-OFDM), resource block-filtered OFDM, filter bank multicarrier (FBMC), and the like.
  • CDMA code division multiple access
  • TDMA time division multiple access
  • FDMA frequency division multiple access
  • OFDMA orthogonal FDMA
  • SC- FDMA single-carrier FDMA
  • ZT UW DTS-s OFDM zero-tail unique-word discrete Fourier transform Spread OFDM
  • UW-OFDM unique word OFDM
  • FBMC filter bank multicarrier
  • the communications system 100 may include wireless transmit/receive units (WTRUs) 102a, 102b, 102c, 102d, a RAN 104/113, a CN 106/115, a public switched telephone network (PSTN) 108, the Internet 110, and other networks 112, though it will be appreciated that the disclosed embodiments contemplate any number of WTRUs, base stations, networks, and/or network elements.
  • WTRUs 102a, 102b, 102c, 102d may be any type of device configured to operate and/or communicate in a wireless environment.
  • the WTRUs 102a, 102b, 102c, 102d may be configured to transmit and/or receive wireless signals and may include a user equipment (UE), a mobile station, a fixed or mobile subscriber unit, a subscription-based unit, a pager, a cellular telephone, a personal digital assistant (PDA), a smartphone, a laptop, a netbook, a personal computer, a wireless sensor, a hotspot or Mi-Fi device, an Internet of Things (IoT) device, a watch or other wearable, a head-mounted display (HMD), a vehicle, a drone, a medical device and applications (e.g., remote surgery), an industrial device and applications (e.g., a robot and/or other wireless devices operating in an industrial and/or an automated processing chain contexts), a consumer electronics device, a device operating on commercial and/or industrial wireless networks, and the like.
  • UE user equipment
  • PDA personal digital assistant
  • smartphone a laptop
  • a netbook a personal computer
  • the communications system 100 may also include a base station 114a and/or a base station 114b.
  • Each of the base stations 114a, 114b may be any type of device configured to wirelessly interface with at least one of the WTRUs 102a, 102b, 102c, 102d to facilitate access to one or more communication networks, such as the CN 106/115, the Internet 110, and/or the other networks 112.
  • the base stations 114a, 114b may be a base transceiver station (BTS), a Node-B, an eNode B, a Home Node B, a Home eNode B, a next generation (gNB), a new radio (NR) NodeB, a site controller, an access point (AP), a wireless router, and the like.
  • a gNB refers to a 5G base station, also referred to as a new radio (NR) base station.
  • eNB, gNB or any other base station may be used interchangeably.
  • the base stations 114a, 114b are each depicted as a single element, it will be appreciated that the base stations 114a, 114b may include any number of interconnected base stations and/or network elements.
  • the base station 114a may be part of the RAN 104/113, which may also include other base stations and/or network elements (not shown), such as a base station controller (BSC), a radio network controller (RNC), relay nodes, etc.
  • BSC base station controller
  • RNC radio network controller
  • the base station 114a and/or the base station 114b may be configured to transmit and/or receive wireless signals on one or more carrier frequencies, which may be referred to as a cell (not shown). These frequencies may be in licensed spectrum, unlicensed spectrum, or a combination of licensed and unlicensed spectrum.
  • a cell may provide coverage for a wireless service to a specific geographical area that may be relatively fixed or that may change over time. The cell may further be divided into cell sectors.
  • the cell associated with the base station 114a may be divided into three sectors.
  • the base station 114a may include three transceivers, i.e., one for each sector of the cell.
  • the base station 114a may employ multiple-input multiple output (MIMO) technology and may utilize multiple transceivers for each sector of the cell.
  • MIMO multiple-input multiple output
  • beamforming may be used to transmit and/or receive signals in desired spatial directions.
  • the base stations 114a, 114b may communicate with one or more of the
  • WTRUs 102a, 102b, 102c, 102d over a respective air interface 116 which may be any suitable wireless communication link (e.g., radio frequency (RF), microwave, centimeter wave, micrometer wave, infrared (TR), ultraviolet (UV), visible light, etc.).
  • the air interface 116 may be established using any suitable radio access technology (RAT).
  • RAT radio access technology
  • the communications system 100 may be a multiple access system and may employ one or more channel access schemes, such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA, and the like.
  • the base station 114a in the RAN 104/113 and the WTRUs 102a, 102b, 102c may implement a radio technology such as Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access (UTRA), which may establish a respective air interface 116 using wideband CDMA (WCDMA).
  • WCDMA may include communication protocols such as High-Speed Packet Access (HSPA) and/or Evolved HSPA (HSPA+).
  • HSPA may include High-Speed Downlink (DL) Packet Access (HSDPA) and/or High-Speed Uplink (UL) Packet Access (HSUPA).
  • the base station 114a and the WTRUs 102a, 102b, 102c may implement a radio technology such as Evolved UMTS Terrestrial Radio Access (E- UTRA), which may establish a respective air interface 116 using Long Term Evolution (LTE) and/or LTE- Advanced (LTE-A) and/or LTE- Advanced Pro (LTE-A Pro).
  • E- UTRA Evolved UMTS Terrestrial Radio Access
  • LTE Long Term Evolution
  • LTE-A LTE- Advanced
  • LTE-A Pro LTE- Advanced Pro
  • the base station 114a and the WTRUs 102a, 102b, 102c may implement a radio technology such as NR Radio Access, which may establish a respective air interface 116 using NR.
  • a radio technology such as NR Radio Access, which may establish a respective air interface 116 using NR.
  • the base station 114a and the WTRUs 102a, 102b, 102c may implement multiple radio access technologies.
  • the base station 114a and the WTRUs 102a, 102b, 102c may implement LTE radio access and NR radio access together, for instance using dual connectivity principles.
  • the air interface utilized by WTRUs 102a, 102b, 102c may be characterized by multiple types of radio access technologies and/or transmissions sent to/from multiple types of base stations (e.g., a e B and a gNB).
  • radio technologies such as IEEE 802.11 (i.e., Wireless Fidelity (WiFi), IEEE 802.16 (i.e., Worldwide Interoperability for Microwave Access (WiMAX)), CDMA2000, CDMA2000 IX, CDMA2000 Evolution Data Only/Evolution Data Optimized (EV-DO), Interim Standard 2000 (IS-2000), Interim Standard 95 (IS-95), Interim Standard 856 (IS-856), Global System for Mobile communications (GSM), Enhanced Data rates for GSM Evolution (EDGE), GSM EDGE (GERAN), and the like.
  • IEEE 802.11 i.e., Wireless Fidelity (WiFi)
  • WiMAX Worldwide Interoperability for Microwave Access
  • CDMA2000 Code Division Multiple Access 2000
  • CDMA2000 IX CDMA2000 Evolution Data Only/Evolution Data Optimized
  • EV-DO Evolution Data Only/Evolution Data Optimized
  • IS-2000 IS-95
  • IS-856 Interim Standard 856
  • the base station 114b in FIG. 1 A may be a wireless router, Home Node B,
  • the base station 114b and the WTRUs 102c, 102d may implement a radio technology such as IEEE 802.11 to establish a wireless local area network (WLAN).
  • the base station 114b and the WTRUs 102c, 102d may implement a radio technology such as IEEE 802.15 to establish a wireless personal area network (WPAN).
  • WLAN wireless local area network
  • WPAN wireless personal area network
  • the base station 114b and the WTRUs 102c, 102d may utilize a cellular-based RAT (e.g., WCDMA, CDMA2000, GSM, LTE, LTE-A, LTE-A Pro, NR etc.) to establish a picocell or femtocell.
  • a cellular-based RAT e.g., WCDMA, CDMA2000, GSM, LTE, LTE-A, LTE-A Pro, NR etc.
  • the base station 114b may have a direct connection to the Internet 110.
  • the base station 114b may not be required to access the Internet 110 via the CN 106/115.
  • the RAN 104/113 may be in communication with the CN 106/115, which may be any type of network configured to provide voice, data, applications, and/or voice over internet protocol (VoIP) services to one or more of the WTRUs 102a, 102b, 102c, 102d.
  • the data may have varying quality of service (QoS) requirements, such as differing throughput requirements, latency requirements, error tolerance requirements, reliability requirements, data throughput requirements, mobility requirements, and the like.
  • QoS quality of service
  • the CN 106/115 may provide call control, billing services, mobile location-based services, prepaid calling, Internet connectivity, video distribution, etc., and/or perform high-level security functions, such as user authentication.
  • the RAN 104/113 and/or the CN 106/115 may be in direct or indirect communication with other RANs that employ the same RAT as the RAN 104/113 or a different RAT.
  • the CN 106/115 may also be in communication with another RAN (not shown) employing a GSM, UMTS, CDMA 2000, WiMAX, E- UTRA, or WiFi radio technology.
  • the CN 106/115 may also serve as a gateway for the WTRUs 102a, 102b,
  • the PSTN 108 may include circuit-switched telephone networks that provide plain old telephone service (POTS).
  • POTS plain old telephone service
  • the Internet 110 may include a global system of interconnected computer networks and devices that use common communication protocols, such as the transmission control protocol (TCP), user datagram protocol (UDP) and/or the internet protocol (IP) in the TCP/IP internet protocol suite.
  • TCP transmission control protocol
  • UDP user datagram protocol
  • IP internet protocol
  • the networks 112 may include wired and/or wireless communications networks owned and/or operated by other service providers.
  • the networks 112 may include another CN connected to one or more RANs, which may employ the same RAT as the RAN 104/113 or a different RAT.
  • Some or all of the WTRUs 102a, 102b, 102c, 102d in the communications system 100 may include multi-mode capabilities (e.g., the WTRUs 102a, 102b, 102c, 102d may include multiple transceivers for communicating with different wireless networks over different wireless links).
  • the WTRU 102c shown in FIG. 1A may be configured to communicate with the base station 114a, which may employ a cellular-based radio technology, and with the base station 114b, which may employ an IEEE 802 radio technology.
  • FIG. IB is a system diagram illustrating an example WTRU 102.
  • the WTRU 102 may include a processor 118, a transceiver 120, a transmit/receive element 122, a speaker/microphone 124, a keypad 126, a display/touchpad 128, non-removable memory 130, removable memory 132, a power source 134, a global positioning system (GPS) chipset 136, and/or other peripherals 138, among others.
  • GPS global positioning system
  • the processor 118 may be a general purpose processor, a special purpose processor, a conventional processor, a digital signal processor (DSP), a plurality of microprocessors, one or more microprocessors in association with a DSP core, a controller, a microcontroller, Application Specific Integrated Circuits (ASICs), Field Programmable Gate Array (FPGA) circuits, any other type of integrated circuit (IC), a state machine, and the like.
  • the processor 118 may perform signal coding, data processing, power control, input/output processing, and/or any other functionality that enables the WTRU 102 to operate in a wireless environment.
  • the processor 118 may be coupled to the transceiver 120, which may be coupled to the transmit/receive element 122. While FIG. IB depicts the processor 118 and the transceiver 120 as separate components, it will be appreciated that the processor 118 and the transceiver 120 may be integrated together in an electronic package or chip.
  • the transmit/receive element 122 may be configured to transmit signals to, or receive signals from, a base station (e.g., the base station 114a) over a respective air interface 116.
  • the transmit/receive element 122 may be an antenna configured to transmit and/or receive RF signals.
  • the transmit/receive element 122 may be an emitter/detector configured to transmit and/or receive IR, UV, or visible light signals, for example.
  • the transmit/receive element 122 may be configured to transmit and/or receive both RF and light signals. It will be appreciated that the transmit/receive element 122 may be configured to transmit and/or receive any combination of wireless signals.
  • the WTRU 102 may include any number of transmit/receive elements 122. More specifically, the WTRU 102 may employ MIMO technology. Thus, in one embodiment, the WTRU 102 may include two or more transmit/receive elements 122 (e.g., multiple antennas) for transmitting and receiving wireless signals over respective air interfaces 116.
  • the WTRU 102 may include two or more transmit/receive elements 122 (e.g., multiple antennas) for transmitting and receiving wireless signals over respective air interfaces 116.
  • the transceiver 120 may be configured to modulate the signals that are to be transmitted by the transmit/receive element 122 and to demodulate the signals that are received by the transmit/receive element 122.
  • the WTRU 102 may have multi-mode capabilities.
  • the transceiver 120 may include multiple transceivers for enabling the WTRU 102 to communicate via multiple RATs, such as R and IEEE 802.11, for example.
  • the processor 118 of the WTRU 102 may be coupled to, and may receive user input data from, the speaker/microphone 124, the keypad 126, and/or the display/touchpad 128 (e.g., a liquid crystal display (LCD) display unit or organic light- emitting diode (OLED) display unit).
  • the processor 118 may also output user data to the speaker/microphone 124, the keypad 126, and/or the display/touchpad 128.
  • the processor 118 may access information from, and store data in, any type of suitable memory, such as the non-removable memory 130 and/or the removable memory 132.
  • the non-removable memory 130 may include random-access memory (RAM), read-only memory (ROM), a hard disk, or any other type of memory storage device.
  • the removable memory 132 may include a subscriber identity module (SIM) card, a memory stick, a secure digital (SD) memory card, and the like.
  • SIM subscriber identity module
  • SD secure digital
  • the processor 118 may access information from, and store data in, memory that is not physically located on the WTRU 102, such as on a server or a home computer (not shown).
  • the processor 118 may receive power from the power source 134, and may be configured to distribute and/or control the power to the other components in the WTRU 102.
  • the power source 134 may be any suitable device for powering the WTRU 102.
  • the power source 134 may include one or more dry cell batteries (e.g., nickel-cadmium (NiCd), nickel-zinc (NiZn), nickel metal hydride (NiMH), lithium-ion (Li-ion), etc.), solar cells, fuel cells, and the like.
  • the processor 118 may also be coupled to the GPS chipset 136, which may be configured to provide location information (e.g., longitude and latitude) regarding the current location of the WTRU 102.
  • location information e.g., longitude and latitude
  • the WTRU 102 may receive location information over a respective air interface 116 from a base station (e.g., base stations 114a, 114b) and/or determine its location based on the timing of the signals being received from two or more nearby base stations. It will be appreciated that the WTRU 102 may acquire location information by way of any suitable location-determination method while remaining consistent with an embodiment.
  • the processor 118 may further be coupled to other peripherals 138, which may include one or more software and/or hardware modules that provide additional features, functionality and/or wired or wireless connectivity.
  • the peripherals 138 may include an accelerometer, an e-compass, a satellite transceiver, a digital camera (for photographs and/or video), a universal serial bus (USB) port, a vibration device, a television transceiver, a hands free headset, a Bluetooth® module, a frequency modulated (FM) radio unit, a digital music player, a media player, a video game player module, an Internet browser, a Virtual Reality and/or Augmented Reality (VR/AR) device, an activity tracker, and the like.
  • FM frequency modulated
  • the peripherals 138 may include one or more sensors, the sensors may be one or more of a gyroscope, an accelerometer, a hall effect sensor, a magnetometer, an orientation sensor, a proximity sensor, a temperature sensor, a time sensor; a geolocation sensor; an altimeter, a light sensor, a touch sensor, a magnetometer, a barometer, a gesture sensor, a biometric sensor, and/or a humidity sensor.
  • a gyroscope an accelerometer, a hall effect sensor, a magnetometer, an orientation sensor, a proximity sensor, a temperature sensor, a time sensor; a geolocation sensor; an altimeter, a light sensor, a touch sensor, a magnetometer, a barometer, a gesture sensor, a biometric sensor, and/or a humidity sensor.
  • the WTRU 102 may include a full duplex radio for which transmission and reception of some or all of the signals (e.g., associated with particular subframes for both the UL (e.g., for transmission) and downlink (e.g., for reception) may be concurrent and/or simultaneous.
  • the full duplex radio may include an interference management unit 139 to reduce and or substantially eliminate self-interference via either hardware (e.g., a choke) or signal processing via a processor (e.g., a separate processor (not shown) or via processor 118).
  • the WTRU 102 may include a half-duplex radio for which transmission and reception of some or all of the signals (e.g., associated with particular subframes for either the UL (e.g., for transmission) or the downlink (e.g., for reception)).
  • a half-duplex radio for which transmission and reception of some or all of the signals (e.g., associated with particular subframes for either the UL (e.g., for transmission) or the downlink (e.g., for reception)).
  • FIG. 1C is a system diagram illustrating the RAN 104 and the CN 106 according to an embodiment.
  • the RAN 104 may employ an E-UTRA radio technology to communicate with the WTRUs 102a, 102b, 102c over respective air interfaces 116.
  • the RAN 104 may also be in communication with the CN 106.
  • the RAN 104 may include eNode-Bs 160a, 160b, 160c, though it will be appreciated that the RAN 104 may include any number of eNode-Bs while remaining consistent with an embodiment.
  • the eNode-Bs 160a, 160b, 160c may each include one or more transceivers for communicating with the WTRUs 102a, 102b, 102c over the respective air interfaces 116.
  • the eNode-Bs 160a, 160b, 160c may implement MIMO technology.
  • the eNode-B 160a for example, may use multiple antennas to transmit wireless signals to, and/or receive wireless signals from, the WTRU 102a.
  • Each of the eNode-Bs 160a, 160b, 160c may be associated with a particular cell (not shown) and may be configured to handle radio resource management decisions, handover decisions, scheduling of users in the UL and/or DL, and the like. As shown in FIG. 1C, the eNode-Bs 160a, 160b, 160c may communicate with one another over an X2 interface.
  • the CN 106 shown in FIG. 1C may include a mobility management entity
  • MME Mobility Management Entity
  • SGW serving gateway
  • PDN packet data network gateway
  • the MME 162 may be connected to each of the eNode-Bs 162a, 162b,
  • the MME 162 may be responsible for authenticating users of the WTRUs 102a, 102b, 102c, bearer activation/deactivation, selecting a particular serving gateway during an initial attach of the WTRUs 102a, 102b, 102c, and the like.
  • the MME 162 may provide a control plane function for switching between the RAN 104 and other RANs (not shown) that employ other radio technologies, such as GSM and/or WCDMA.
  • the SGW 164 may be connected to each of the eNode Bs 160a, 160b,
  • the SGW 164 may generally route and forward user data packets to/from the WTRUs 102a, 102b, 102c.
  • the SGW 164 may perform other functions, such as anchoring user planes during inter-eNode B handovers, triggering paging when DL data is available for the WTRUs 102a, 102b, 102c, managing and storing contexts of the WTRUs 102a, 102b, 102c, and the like.
  • the SGW 164 may be connected to the PGW 166, which may provide the
  • WTRUs 102a, 102b, 102c with access to packet-switched networks, such as the Internet 110, to facilitate communications between the WTRUs 102a, 102b, 102c and IP-enabled devices.
  • packet-switched networks such as the Internet 110
  • the CN 106 may facilitate communications with other networks.
  • the CN 106 may provide the WTRUs 102a, 102b, 102c with access to circuit- switched networks, such as the PSTN 108, to facilitate communications between the WTRUs 102a, 102b, 102c and traditional land-line communications devices.
  • the CN 106 may include, or may communicate with, an IP gateway (e.g., an IP multimedia subsystem (IMS) server) that serves as an interface between the CN 106 and the PSTN 108.
  • IMS IP multimedia subsystem
  • the CN 106 may provide the WTRUs 102a, 102b, 102c with access to the other networks 112, which may include other wired and/or wireless networks that are owned and/or operated by other service providers.
  • the WTRU is described in FIGS. 1A-1D as a wireless terminal, it is contemplated that in certain representative embodiments that such a terminal may use (e.g., temporarily or permanently) wired communication interfaces with the communication network.
  • the other network 112 may be a WLAN.
  • a WLAN in Infrastructure Basic Service Set (BSS) mode may have an
  • the AP may have an access or an interface to a Distribution System (DS) or another type of wired/wireless network that carries traffic in to and/or out of the BSS.
  • Traffic to STAs that originates from outside the BSS may arrive through the AP and may be delivered to the STAs.
  • Traffic originating from STAs to destinations outside the BSS may be sent to the AP to be delivered to respective destinations.
  • Traffic between STAs within the BSS may be sent through the AP, for example, where the source STA may send traffic to the AP and the AP may deliver the traffic to the destination STA.
  • DS Distribution System
  • the traffic between STAs within a BSS may be considered and/or referred to as peer-to-peer traffic.
  • the peer-to-peer traffic may be sent between (e.g., directly between) the source and destination STAs with a direct link setup (DLS).
  • the DLS may use an 802.1 le DLS or an 802.1 lz tunneled DLS (TDLS).
  • a WLAN using an Independent BSS (IBSS) mode may not have an AP, and the STAs (e.g., all of the STAs) within or using the IBSS may communicate directly with each other.
  • the IBSS mode of communication may sometimes be referred to herein as an "ad-hoc" mode of communication.
  • the AP may transmit a beacon on a fixed channel, such as a primary channel.
  • the primary channel may be a fixed width (e.g., 20 MHz wide bandwidth) or a dynamically set width via signaling.
  • the primary channel may be the operating channel of the BSS and may be used by the STAs to establish a connection with the AP.
  • Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA) may be implemented, for example in in 802.11 systems.
  • the STAs e.g., every STA, including the AP, may sense the primary channel. If the primary channel is sensed/detected and/or determined to be busy by a particular STA, the particular STA may back off.
  • One STA (e.g., only one station) may transmit at any given time in a given BSS.
  • High Throughput (HT) STAs may use a 40 MHz wide channel for communication, for example, via a combination of the primary 20 MHz channel with an adjacent or nonadjacent 20 MHz channel to form a 40 MHz wide channel.
  • VHT Very High Throughput STAs may support 20MHz, 40 MHz, 80
  • the 40 MHz, and/or 80 MHz, channels may be formed by combining contiguous 20 MHz channels.
  • a 160 MHz channel may be formed by combining 8 contiguous 20 MHz channels, or by combining two non-contiguous 80 MHz channels, which may be referred to as an 80+80 configuration.
  • the data after channel encoding, may be passed through a segment parser that may divide the data into two streams. Inverse Fast Fourier Transform (IFFT) processing, and time domain processing, may be done on each stream separately.
  • IFFT Inverse Fast Fourier Transform
  • the streams may be mapped on to the two 80 MHz channels, and the data may be transmitted by a transmitting STA.
  • the above described operation for the 80+80 configuration may be reversed, and the combined data may be sent to the Medium Access Control (MAC).
  • MAC Medium Access Control
  • Sub 1 GHz modes of operation are supported by 802.11af and 802.1 lah.
  • the channel operating bandwidths, and carriers, are reduced in 802.11af and 802.1 lah relative to those used in 802.11 ⁇ , and 802.1 lac.
  • 802. l laf supports 5 MHz, 10 MHz and 20 MHz bandwidths in the TV White Space (TVWS) spectrum
  • 802.1 lah supports 1 MHz, 2 MHz, 4 MHz, 8 MHz, and 16 MHz bandwidths using non-TVWS spectrum.
  • 802.1 lah may support Meter Type Control/Machine-Type Communications, such as MTC devices in a macro coverage area.
  • MTC devices may have certain capabilities, for example, limited capabilities including support for (e.g., only support for) certain and/or limited bandwidths.
  • the MTC devices may include a battery with a battery life above a threshold (e.g., to maintain a very long battery life).
  • WLAN systems which may support multiple channels, and channel bandwidths, such as 802.11 ⁇ , 802.1 lac, 802.11af, and 802.1 lah, include a channel which may be designated as the primary channel.
  • the primary channel may have a bandwidth equal to the largest common operating bandwidth supported by all STAs in the BSS.
  • the bandwidth of the primary channel may be set and/or limited by a STA, from among all STAs in operating in a BSS, which supports the smallest bandwidth operating mode.
  • the primary channel may be 1 MHz wide for STAs (e.g., MTC type devices) that support (e.g., only support) a 1 MHz mode, even if the AP, and other STAs in the BSS support 2 MHz, 4 MHz, 8 MHz, 16 MHz, and/or other channel bandwidth operating modes.
  • Carrier sensing and/or Network Allocation Vector (NAV) settings may depend on the status of the primary channel. If the primary channel is busy, for example, due to a STA (which supports only a 1 MHz operating mode), transmitting to the AP, the entire available frequency bands may be considered busy even though a majority of the frequency bands remains idle and may be available.
  • STAs e.g., MTC type devices
  • NAV Network Allocation Vector
  • 802.11 ah are from 902 MHz to 928 MHz. In Korea, the available frequency bands are from 917.5 MHz to 923.5 MHz. In Japan, the available frequency bands are from 916.5 MHz to 927.5 MHz. The total bandwidth available for 802.11 ah is 6 MHz to 26 MHz depending on the country code.
  • FIG. ID is a system diagram illustrating the RAN 113 and the CN 115 according to an embodiment.
  • the RAN 113 may employ an NR radio technology to communicate with the WTRUs 102a, 102b, 102c over respective air interfaces 116.
  • the RAN 113 may also be in communication with the CN 1 15.
  • the RAN 113 may include gNBs 180a, 180b, 180c, though it will be appreciated that the RAN 113 may include any number of gNBs while remaining consistent with an embodiment.
  • the gNBs 180a, 180b, 180c may each include one or more transceivers for communicating with the WTRUs 102a, 102b, 102c over the respective air interfaces 116.
  • the gNBs 180a, 180b, 180c may implement MFMO technology.
  • gNBs 180a, 108b may utilize beamforming to transmit signals to and/or receive signals from the gNBs 180a, 180b, 180c.
  • the gNB 180a may use multiple antennas to transmit wireless signals to, and/or receive wireless signals from, the WTRU 102a.
  • the gNBs 180a, 180b, 180c may implement carrier aggregation technology.
  • the gNB 180a may transmit multiple component carriers to the WTRU 102a (not shown). A subset of these component carriers may be on unlicensed spectrum while the remaining component carriers may be on licensed spectrum.
  • the gNBs 180a, 180b, 180c may implement Coordinated Multi -Point (CoMP) technology.
  • WTRU 102a may receive coordinated transmissions from gNB 180a and gNB 180b (and/or gNB 180c).
  • CoMP Coordinated Multi -Point
  • the WTRUs 102a, 102b, 102c may communicate with gNBs 180a, 180b,
  • the WTRUs 102a, 102b, 102c may communicate with gNBs 180a, 180b, 180c using subframe or transmission time intervals (TTIs) of various or scalable lengths (e.g., containing varying number of OFDM symbols and/or lasting varying lengths of absolute time).
  • TTIs subframe or transmission time intervals
  • the gNBs 180a, 180b, 180c may be configured to communicate with the
  • WTRUs 102a, 102b, 102c in a standalone configuration and/or a non- standalone configuration.
  • WTRUs 102a, 102b, 102c may communicate with gNBs 180a, 180b, 180c without also accessing other RANs (e.g., such as eNode-Bs 160a, 160b, 160c).
  • WTRUs 102a, 102b, 102c may utilize one or more of gNBs 180a, 180b, 180c as a mobility anchor point.
  • WTRUs 102a, 102b, 102c may communicate with gNBs 180a, 180b, 180c using signals in an unlicensed band.
  • WTRUs 102a, 102b, 102c may communicate with/connect to gNBs 180a, 180b, 180c while also communicating with/connecting to another RAN such as eNode-Bs 160a, 160b, 160c.
  • WTRUs 102a, 102b, 102c may implement dual connectivity principles to communicate with one or more gNBs 180a, 180b, 180c and one or more eNode-Bs 160a, 160b, 160c substantially simultaneously.
  • eNode-Bs 160a, 160b, 160c may serve as a mobility anchor for WTRUs 102a, 102b, 102c and gNBs 180a, 180b, 180c may provide additional coverage and/or throughput for servicing WTRUs 102a, 102b, 102c.
  • Each of the gNBs 180a, 180b, 180c may be associated with a particular cell (not shown) and may be configured to handle radio resource management decisions, handover decisions, scheduling of users in the UL and/or DL, support of network slicing, dual connectivity, interworking between NR and E-UTRA, routing of user plane data towards User Plane Function (UPF) 184a, 184b, routing of control plane information towards Access and Mobility Management Function (AMF) 182a, 182b and the like. As shown in FIG. ID, the gNBs 180a, 180b, 180c may communicate with one another over an Xn interface.
  • UPF User Plane Function
  • AMF Access and Mobility Management Function
  • the CN 115 shown in FIG. ID may include at least one AMF 182a, 182b, at least one UPF 184a, 184b, at least one Session Management Function (SMF) 183a, 183b, and possibly a Data Network (DN) 185a, 185b. While each of the foregoing elements are depicted as part of the CN 115, it will be appreciated that any of these elements may be owned and/or operated by an entity other than the CN operator.
  • SMF Session Management Function
  • the AMF 182a, 182b may be connected to one or more of the gNBs 180a,
  • the AMF 182a, 182b may be responsible for authenticating users of the WTRUs 102a, 102b, 102c, support for network slicing (e.g., handling of different PDU sessions with different requirements), selecting a particular SMF 183a, 183b, management of the registration area, termination of NAS signaling, mobility management, and the like.
  • Network slicing may be used by the AMF 182a, 182b in order to customize CN support for WTRUs 102a, 102b, 102c based on the types of services being utilized WTRUs 102a, 102b, 102c.
  • the AMF 182a, 182b may provide a control plane function for switching between the RAN 113 and other RANs (not shown) that employ other radio technologies, such as LTE, LTE-A, LTE-A Pro, and/or non-3GPP access technologies such as WiFi.
  • the SMF 183a, 183b may be connected to an AMF 182a, 182b in the CN
  • the SMF 183a, 183b may also be connected to a UPF 184a, 184b in the CN 115 via an N4 interface.
  • the SMF 183a, 183b may select and control the UPF 184a, 184b and configure the routing of traffic through the UPF 184a, 184b.
  • the SMF 183a, 183b may perform other functions, such as managing and allocating UE IP address, managing PDU sessions, controlling policy enforcement and QoS, providing downlink data notifications, and the like.
  • a PDU session type may be IP-based, non-IP based, Ethernet-based, and the like.
  • the UPF 184a, 184b may be connected to one or more of the gNBs 180a,
  • the UPF 184, 184b may perform other functions, such as routing and forwarding packets, enforcing user plane policies, supporting multi-homed PDU sessions, handling user plane QoS, buffering downlink packets, providing mobility anchoring, and the like.
  • the CN 115 may facilitate communications with other networks.
  • the CN 115 may include, or may communicate with, an IP gateway (e.g., an IP multimedia subsystem (IMS) server) that serves as an interface between the CN 115 and the PSTN 108.
  • IP gateway e.g., an IP multimedia subsystem (IMS) server
  • IMS IP multimedia subsystem
  • the CN 115 may provide the WTRUs 102a, 102b, 102c with access to the other networks 112, which may include other wired and/or wireless networks that are owned and/or operated by other service providers.
  • the WTRUs 102a, 102b, 102c may be connected to a local Data Network (DN) 185a, 185b through the UPF 184a, 184b via the N3 interface to the UPF 184a, 184b and an N6 interface between the UPF 184a, 184b and the DN 185a, 185b.
  • DN local Data Network
  • 1D one or more, or all, of the functions described herein with regard to one or more of: WTRU 102a-d, Base Station 114a-b, eNode-B 160a-c, MME 162, SGW 164, PGW 166, g B 180a-c, AMF 182a-ab, UPF 184a-b, SMF 183a-b, DN 185a-b, and/or any other device(s) described herein, may be performed by one or more emulation devices (not shown).
  • the emulation devices may be one or more devices configured to emulate one or more, or all, of the functions described herein.
  • the emulation devices may be used to test other devices and/or to simulate network and/or WTRU functions.
  • the emulation devices may be designed to implement one or more tests of other devices in a lab environment and/or in an operator network environment.
  • the one or more emulation devices may perform the one or more, or all, functions while being fully or partially implemented and/or deployed as part of a wired and/or wireless communication network in order to test other devices within the communication network.
  • the one or more emulation devices may perform the one or more, or all, functions while being temporarily implemented/deployed as part of a wired and/or wireless communication network.
  • the emulation device may be directly coupled to another device for purposes of testing and/or may performing testing using over-the-air wireless communications.
  • the one or more emulation devices may perform the one or more, including all, functions while not being implemented/deployed as part of a wired and/or wireless communication network.
  • the emulation devices may be utilized in a testing scenario in a testing laboratory and/or a non-deployed (e.g., testing) wired and/or wireless communication network in order to implement testing of one or more components.
  • the one or more emulation devices may be test equipment. Direct RF coupling and/or wireless communications via RF circuitry (e.g., which may include one or more antennas) may be used by the emulation devices to transmit and/or receive data.
  • RF circuitry e.g., which may include one or more antennas
  • a codeword represents the user data before it is formatted for transmission.
  • codewords are simply separate streams of data that contain the information to be sent through a physical channel.
  • at least one or two code words e.g., CW0 and CW1 may be used depending on the conditions of the channel and the use case.
  • Each codeword has a blocklength (i.e., the length of a codeword in symbols), also referred to as a transport blocklength.
  • codeword blocklength may significantly affect the performance of the code.
  • bit error rate (BER) and the frame error rate (FER) may be examined as functions of the signal-to-noise ratio per bit E /No, respectively, for a low-density parity-check (LDPC) code.
  • the LDPC code may be a regular LDPC code, with rate 1/2 and column weight 3.
  • the modulation scheme may be binary phase shift keying (BPSK), and the channel model may be Additive White Gaussian Noise (AWGN).
  • BPSK binary phase shift keying
  • AWGN Additive White Gaussian Noise
  • blocklength may be varied from 200 to 2000 symbols.
  • FIG. 2A is a graph illustrating an effect of blocklength on the block error rate (BER) performance for binary phase shift keying (BPSK) and low-density parity- check (LDPC) using the aforementioned conditions (e.g., with rate 1/2, column weight 3, etc.).
  • BER block error rate
  • BPSK binary phase shift keying
  • LDPC low-density parity- check
  • FIG. 2B is a graph illustrating an effect of blocklength on the frame error rate (FER) performance for BPSK and LDPC using the aforementioned conditions (e.g., with rate 1/2, column weight 3, etc.).
  • the maximum achievable rate for a given blocklength and an FER has been characterized mathematically where the formulation shows that the maximum achievable rate for a blocklength n for a given FER ⁇ is less than the channel capacity (i.e., the maximum rate at n ⁇ ) by an amount inversely proportional to the square root of n.
  • the maximum rate is approximately:
  • Equation 1 n is the blocklength, ⁇ is the frame error probability, Q _1 () is the inverse of the Q function, C is the channel capacity, and V is a parameter called the channel dispersion that is independent of n and ⁇ . It is clear that in order to keep the same frame error probability, as the blocklength decreases, the maximum rate should decrease as well. [0088] The implication is that when short packets are considered, for example, in ultra-low-latency communication, then the coding rate may have to be lowered. A normal approximation ⁇ line h), along with the upper bound (line g) and the lower bound (line / ' ), is shown in FIG. 3.
  • channel state information including channel quality indicator (CQI), Precoding Matrix Index (PMI), Rank Indicator (RI), may be fed back from the WTRU to the e B without considering the difference in performance for different blocklengths.
  • the modulation scheme may be conveyed from the eNB to the WTRU via the Downlink Control Information (DCI) field through the Physical Downlink Control Channel (PDCCH).
  • DCI Downlink Control Information
  • PDCCH Physical Downlink Control Channel
  • the actual coding rate may be determined by the transport block size and the allocated resource blocks minus the resource elements used for reference and control purposes. It is noted that rate matching may be used to fill out all the resource elements available for data transmission by taking a subset of bits from the output of a fixed-rate mother code.
  • the modulation and coding scheme may be determined by the effective signal-to-interference-plus-noise ratio (SINR).
  • SI M CS effective signal-to-interference-plus-noise ratio
  • the eNB may determine the MCS and send an MCS index (I M CS) corresponding to the determined MCS to the WTRU.
  • I M CS MCS index
  • BLER target block error rate
  • the coding rate at a shorter blocklength should be lower.
  • the MCS which reflects the desired coding rate, should be adjusted to account for different codeword blocklengths and/or different target BLER.
  • this is not the case in current LTE and LTE-A systems.
  • FIG. 4 is a graph illustrating the actual coding rate as a function of the blocklength for different modulation and coding scheme (MCS) values (I M CS) in current LTE/LTE-A systems.
  • MCS modulation and coding scheme
  • the cyclic redundancy check is 24 bits, and the percentage of resource blocks being used for the information bits (i.e., the size of which is the transport block size) is 90%.
  • the coding rate as depicted in FIG. 4 will lead to higher BLER for shorter blocklengths, which may be undesirable because in order to maximize the useful throughput for automatic repeat request (ARQ) under some channel conditions, a fixed target BLER such as 10% is near optimal.
  • each embodiment may include one or more channel feedback schemes for adjusting the coding rate (e.g., MCS) based on codeword blocklength that may vary across different downlink (DL) data transmissions.
  • each embodiment may include one or more channel feedback schemes for adjusting the coding rate based one or more transmission parameters that may vary across different DL data transmissions, including but not limited to codeword blocklength, channel code type, and/or a target BLER, which may include a target BLER range.
  • different codeword blocklengths, different channel code types, different target BLERs, and/or different target BLER ranges may be implemented by an eNB or a gNB, and a particular set of DL transmission parameters (e.g., codeword blocklength, channel code type, a target BLER, and/or target BLER range) may be selected by the eNB or the gNB depending on the type of data transmission and other transmission conditions.
  • DL transmission parameters may also be referred to as target performance criteria or DL reception parameters, and may include one or more QoS requirements (e.g., a target BLER).
  • the coding rate may be adjusted according to the blocklength such that a substantially constant BLER (i.e., within an acceptable margin) is achieved at all blocklengths.
  • a receiver may inform a transmitter (e.g., an eNB, gNB, etc.) of one or more channel code types that the receiver can support when the transmitter and the receiver first establish a connection.
  • a model may be used to generate the coding rate as a function of the blocklength for a target BLER.
  • the model may be a combination of theoretical results and empirical results.
  • This model may consider the characteristics of practical channel codes such as Reed-Muller code, convolutional code, Turbo code, LDPC or Polar code.
  • This function may be an increasing function of the blocklength such that coding rate increases as blocklength increases and may capture the effect of finite blocklength on the channel coding performance.
  • Each curve may be characterized by the modulation scheme, the target BLER, and the type of channel code.
  • the transport block size (i.e., the defined number of bits in a Transport Block (TB)) may be determined for various amounts of resource to be allocated, and a table may be formed, which may have sub-tables associated with the modulation scheme, the target BLER, and the channel code type.
  • the table may be agreed upon between the transmitter and the receiver.
  • the transmitter may inform the receiver about the modulation scheme, target BLER, and the channel code in addition to the resource allocation so that the receiver can identify the correct sub-tables from the table.
  • the receiver In order to generate the model of the coding rate as a function of the blocklength for a target BLER, the receiver (e.g., the WTRU) may observe the signal reception over an unrestricted amount of time and construct curves that are similar to the normal approximation line shown in FIG. 3.
  • a curve may be denoted as r(n, ⁇ , M), where n is the blocklength, ⁇ is the BLER, and M denotes the modulation scheme (e.g., BPSK, Quadrature Phase Shift Keying (QPSK), 16 Quadrature Amplitude Modulation (QAM), 64 QAM).
  • a model may be generated by the receiver to approximate the channel dispersion using methods such as a least squares method which generates a best fit result for representing the collected data points.
  • FIGS. 5A and 5B An example of a curve is shown in FIGS. 5A and 5B, which provide both the channel dispersion J 7 and the capacity C.
  • FIGS. 5 A and 5B shows a least square method for building an empirical curve that describes the code rate as a function of the blocklength for a given BLER and modulation scheme, where the crosses are empirical data and the solid line is the least squares result.
  • the receiver observes previous transmissions and records the rate and blocklength information for a fixed channel quality, modulation scheme, and BLER, resulting in m pairs (n 1? Ri), (n 2 , R 2 ), (n K , R k ), where ni...n K are blocklengths, and Ri...R k are coding rates.
  • Equation (2) A matrix A and a vector R are respectively formed as follows: Equation (2)
  • V ( ⁇ 3 ⁇ 4) 2 Equation (7)
  • X(l) and X(2) are the first and second component of vector X
  • Q _1 () is the inverse of the Q function
  • ⁇ is the frame error probability
  • blocklength may be taken into account for CSI feedback.
  • the WTRU may measure the channel quality (i.e., CSI) corresponding to the channel on which control information (e.g., reference signal, pilot signal, etc.) is received and recommend an MCS in the form of a CQI to the eNB (or gNB) based on the CSI and target performance criteria (i.e., control information) received from the base station over a control channel (e.g., PDCCH).
  • CSI channel quality
  • control information e.g., reference signal, pilot signal, etc.
  • the WTRU may determine an optimal CQI (i.e., a WTRU-based CQI) based on the CSI and the target performance criteria, and transmit the (optimal) WTRU-based CQI back to the base station over a control channel (e.g., PUCCH).
  • a control channel e.g., PUCCH
  • the eNB may receive the WTRU-based CQI, and conduct its own final determination on a CQI, taking into account the WTRU-based CQI from the WTRU. That is, the eNB may use the WTRU-based CQI received from the WTRU or select a different CQI after considering the WTRU-based CQI, where the WTRU-based CQI may be used as a reference point for selecting the different CQI. After determining the final CQI (i.e., the network-based CQI), the eNB may use the final, network-based CQI to determine the MCS and the TBS to be used.
  • the final CQI i.e., the network-based CQI
  • the eNB may then convey the determined MCS (e.g., in the form of the final, network-based CQI) and TBS to the WTRU, and finally transmit the downlink data thereafter (e.g., after the WTRU receives the determined MCS and TBS).
  • the eNB selects an MCS without the impact of the transport blocklength on the link performance being considered, it may either use a conservative MCS (more robust than necessary), in which case network resource may be wasted, or may use an aggressive MCS (less robust than necessary), in which case the link performance (e.g., the BLER) may not be achieved.
  • CSI feedback may be important to the link performance because the receiver (e.g., the WTRU for downlink) conveys the quality of the effective communication channel, including the effects of the radio frequency (RF) and baseband processing such as RF impairments, precision of the Analog-to-Digital (AID) conversion, the equalization capability and the channel decoding algorithm which may not be known to the transmitter.
  • RF radio frequency
  • AID Analog-to-Digital
  • there may be a blocklength-specific CQI reporting where the eNB (or gNB) notifies the WTRU of the amount of data (i.e., the transport block size) for a future transmission.
  • the WTRU determines the MCS and the blocklength needed for the eNB to deliver the data with a target performance (e.g., a target BLER), based on one or more assumptions, such as, an assumption that the transport block will be transmitted on the resources that have the best channel condition to that WTRU.
  • the WTRU may then determine the CQI corresponding to the MCS.
  • the MCS implicitly corresponds to the blocklength determined by the WTRU and this is referred to as a blocklength-specific CQI to distinguish it from blocklength-agonistic CQI' s.
  • the WTRU then transmits the blocklength-specific CQI to the eNB as a recommendation for the MCS.
  • the WTRU may indicate to the eNB which resource blocks the
  • the WTRU may send the blocklength information to the eNB.
  • the eNB may derive the blocklength from the amount of data to transmit and the MCS corresponding to the received CQI when the blocklength information is not sent to the eNB by the WTRU, or it may read the blocklength information when the WTRU has optionally sent the blocklength information to the eNB. Based on the received CQI and the determined or read blocklength, the eNB may select an MCS that is the same or different from the MCS corresponding to the CQI recommended by the WTRU.
  • the eNB determines the final MCS to be used, allocates the resource needed to serve the amount of data, which may also be based on the resource blocks indicated by the WTRU, and sends the final MCS and the resource allocation information to the WTRU. After n Time Transmission Intervals (TTFs), the eNB transmits the data on the downlink to the WTRU, where n is a natural number.
  • TTFs Time Transmission Intervals
  • This approach may allow the blocklength information to be fully utilized in determining the MCS, resulting in the highest possible spectral efficiency while meeting the target link requirements.
  • this may change the current CSI feedback paradigm of LTE/LTE-A systems. For example, periodic CSI feedback may not work since DL resource assignments are not periodically sent by the eNB.
  • feeding back the blocklength-specific CQI only after the transport block size is determined may incur additional delay, which may be at least 4 TTIs long as shown in FIG. 6.
  • FIG. 6 is a timing diagram of a data transmission procedure
  • the eNB sends the WTRU information indicating the size of the new data and waits for the blocklength-specific CQI before data transmission.
  • data to be transmitted to WTRU k arrives at the eNB at 605, where WTRU k is one of multiple WTRUs that are served by the eNB.
  • the eNB determines a TBS for a data transmission for sending the data, and notifies WTRU k of the TBS at 610.
  • WTRU k Upon receiving the TBS, WTRU k determines the blocklength and the blocklength-specific CQI (i.e., corresponding to an MCS) needed for the eNB to deliver the data with a target performance, and sends the blocklength-specific CQI to the eNB at 615.
  • the eNB Upon receiving the blocklength-specific CQI, the eNB processes the blocklength-specific CQI, determines a final, network-based CQI, and determines an MCS that corresponds to the final, network-based CQI based on CQI-MCS mapping information (e.g., CQI-MCS table). The eNB also determines a resource allocation needed to serve the amount of data.
  • the eNB transmits the MCS and the resource allocation information to WTRU k.
  • the eNB transmits the data to WTRU k.
  • the eNB may determine a resource allocation first based on prior knowledge about the CSI of the WTRU. The WTRU may then feed back the blocklength-specific CQI. This approach is shown in FIG. 7.
  • FIG. 7 is a timing diagram of a data transmission procedure
  • the eNB sends WTRU k resource allocation information and waits for the blocklength-specific CQI before a data transmission.
  • data to be transmitted to WTRU k arrives at the eNB.
  • the eNB determines a resource allocation and, at 710, transmits the resource allocation information to WTRU k.
  • WTRU k is triggered to determine the blocklength and the blocklength-specific CQI (i.e., corresponding to an MCS) needed for the eNB to deliver the data with a target performance on the resource indicated in the resource allocation information.
  • WTRU k sends the blocklength-specific CQI to the eNB.
  • the eNB Upon receiving the blocklength-specific CQI, the eNB processes the blocklength-specific CQI, determines a final CQI, and determines an MCS that corresponds to the final CQI based on CQI-MCS mapping information (e.g., CQI-MCS table). At 720, the eNB transmits the data to WTRU k.
  • CQI-MCS mapping information e.g., CQI-MCS table
  • FIG. 8 is a timing diagram of a data transmission procedure 800 where the
  • FIG. 8 shows a third embodiment where the receiver (e.g., a WTRU) may proactively send multiple CQIs, each associated with a different range of blocklengths, to the eNB.
  • the receiver e.g., a WTRU
  • WTRU k may assume that its best resources are used by the eNB to transmit transport blocks of various hypothetical sizes.
  • WTRU k determines a CQI for each range of blocklengths, and sends the CQIs to the eNB, along with information that indicates to which blocklength range each CQI corresponds.
  • the eNB may not need to go through the process of notifying the WTRU of the transport block size and waiting for the WTRU to feed back a blocklength- specific CQI before the data transmission. Instead, when the new data arrives at 810, the eNB may determine a blocklength based on the data, and determine a final CQI/MCS by referring to a CQI among the multiple CQIs received from WTRU k.
  • the CQI referred to is the CQI that corresponds to the blocklength range that contains the blocklength determined by the eNB.
  • the eNB sends resource assignment information and the final CQI or MCS (e.g., via the control channel), and, subsequently, sends the data (e.g., via the data channel) to WTRU k.
  • the control information including resource allocation and the final CQI or MCS, is sent at the beginning of a TTI, and the data follows but still in the same TTI.
  • a CQI table may be created for each blocklength range.
  • the blocklength range specifies a range of blocklengths. As an example, two ranges may be used: 1 ⁇ blocklength ⁇ 150, and blocklength > 150.
  • FEC forward error correction
  • the receiver e.g., a WTRU
  • the transmitter e.g., a base station
  • the receiver sends a single CQI for a particular blocklength known to both the receiver and the transmitter
  • the transmitter e.g., a base station
  • the transmitter adjusts the MCS based on the actual blocklength to be used.
  • the transmitter may adjust the CQI based on the difference of the blocklength used by the receiver in deriving the reported CQI and the blocklength of the actual transmission.
  • the WTRU uses blocklength ni to derive a CQI, which gives a rate R n ⁇ ⁇ ) .
  • the eNB then proceeds to determine the MCS, informs the WTRU of the
  • the CQI report may contain multiple CQI values, each of which corresponds to a particular modulation scheme (i.e., MCS).
  • MCS modulation scheme
  • C(ji) and V(y ) are the channel capacity and the channel dispersion of the AWGN channel, respectively, with SNR Yi and PAM input signals under equiprobable input constraint.
  • C(ji) and V( t) are provided as: c(yd log 7 Equation (10) V y0 Equation (1 1)
  • the modulation scheme is a rectangular QAM, such as 16QAM or
  • a QAM constellation may be decomposed into two independent PAM constellations, and aspects of the fourth embodiment described herein may be applied.
  • Equation (9) In the case where the noise may not be Gaussian, but independent across the channels, the bound according to Equation (9) still holds, except that the distributions VY i ⁇ x i in equations (10) and (1 1) may no longer be Gaussian. If the noises are not independent across the channels, a whitening transformation may be applied to the received signals on the channels to transform the noises into independent random variables before any further processing.
  • each stream/layer can be considered as one of the
  • a subcarrier or a group of subcarriers with similar SINR can be considered as one of the / parallel channels.
  • the parallel channels are agreed upon between the transmitter and the receiver.
  • FIG. 9 shows the parallel channels in an OFDMA system.
  • the blocklength n for each parallel channel may be equal to the number of subcarriers per resource block multiplied by the number of resource blocks on the channel.
  • the receiver may select / parallel channels and report the channel dispersion parameters of these selected channels.
  • a channel may consist of multiple resource blocks, each of which in turn may consist of multiple subcarriers. [0124]
  • the receiver can notify the transmitter of the parameters n, y y t .
  • the transmitter may determine the target BLER ⁇ , the modulation scheme, and which subset of the parallel channels to use for transmission to that receiver (assuming the first s parallel channels are selected), and then uses Equations (9), (10) and (11) to calculate an estimate of R * (ns, ⁇ , y y s ).
  • the transmitter informs the receiver about the MCS and the resource allocation, and transmits the data.
  • the receiver may notify the transmitter of the parameters C(ji) and V(y ), l ⁇ i ⁇ l.
  • FIG. 10 illustrates a block diagram showing an information exchange between a transmitter and receiver in a wireless communications system 1000 according to one or more embodiments.
  • the wireless communications system 1000 includes transmitter 1010 and receiver 1020 that exchange information over respective control channels (e.g., PUCCH 1005 and PDCCH 1015).
  • the receiver 1020 e.g., a WTRU
  • the transmitter 1010 may be configured to determine an MCS from the received channel dispersion and channel capacity to meet a target BLER for one or more of the parallel channels.
  • receiver 1020 may send channel dispersions, channel capacities, CSIs and/or CQIs of the parallel channels on PUCCH 1005, and, in response, the transmitter 1010 may send resource allocation information, target BLER, channel code type and/or MCS on PDCCH 1015.
  • the channel dispersions may be fed back from the receiver
  • the transmitter 1010 may also inform the receiver on the types of channel code (e.g., convolutional code, Turbo code, LDPC, Polar code) to be used because at a given blocklength one channel code may perform better than the others.
  • the target BLER may also be sent to the receiver 1020, for example, to help the receiver 1020 correctly identify the transport block size table that corresponds to the target BLER.
  • feeding back quantized CSI may be performed.
  • the receiver estimates the channel, and feeds back quantized CSI.
  • the CSI may be in the form of a quantized version of the channel matrix. For example, if for the transmission from the eNB to the WTRU there are M transmit antennas and N receive antennas, the channel matrix may be an MxN matrix. This way, the transmitter may have more accurate information about the channel than it can get in the current CSI feedback approach where CQI, RI and PMI are fed back to the transmitter. Additionally, given the actual CSI, the transmitter may use the transport block size (that is known to the transmitter) to determine the MCS, resource allocation, and codeword blocklength for an upcoming data transmission. This may result in performance gain because the MCS is made to match the codeword blocklength.
  • the formulas in Equations (1), (9), (10) and (11) or variants of them may be used to take into account the effect of the blocklength.
  • a hybrid approach may be taken in which the transmitter may send a multi-bit information to the receiver that indicates the channel feedback scheme.
  • the multi-bit information may be expressed by three bits.
  • x may refer to any other feedback scheme disclosed herein, for example, those described in subsequent paragraphs or those derived from combining two or more embodiments disclosed herein, or may be reserved for a fallback scheme developed in the future. Furthermore, more or less than three bits may be used for the channel feedback scheme indicator.
  • a decision on which channel feedback scheme to use may depend on the quality of service (QoS) requirement of the data to be served. For example, for low- latency traffic, the second embodiment described herein may be selected, while for high- throughput traffic without stringent latency constraints, the first embodiment described herein may be a better choice.
  • QoS quality of service
  • FIG. 11 illustrates a block diagram showing an information exchange in a wireless communications system 1100 according to one or more embodiments.
  • the wireless communications system 1100 includes a g B 1110 and a WTRU 1120 in communication with each other.
  • the gNB 1110 may send DL transmission parameters (i.e., target performance criteria) over a PDCCH as control information in one or more transmissions.
  • the DL transmission parameters including channel code type, (e.g., LDPC, Polar code, Turbo code, etc.), codeword blocklength, target BLER or target BLER range, and/or other information, may be included in DCI sent to the WTRU 1 120.
  • the WTRU 1120 may send a recommended CQI corresponding to (e.g., mapped to) a recommended MCS to the gNB 1110 over a PUCCH.
  • Sending DL transmission parameters may include the gNB 1110 sending the channel code type used for the next or scheduled data transmission, the codeword blocklength of the next or scheduled data transmission, the target BLER for the next or scheduled data transmission, and possibly other information to the WTRU 1120 so that the WTRU 1120 can better estimate (i.e., optimize) the CQI that achieves the expected performance for the downlink data transmission.
  • the WTRU 1120 Upon receiving the DL transmission parameters, the WTRU 1120 measures the CSI corresponding to the channel on which the control information (e.g., the reference signal) is received, and uses the measured CSI and at least one of the DL transmission parameters to determine the optimized CQI. It is also possible that the WTRU 1120 measures the CSI prior to receiving the DL transmission parameters, if, for instance, the reference signal is a cell-specific reference signal (CRS), which is common to all WTRUs.
  • CRS cell-specific reference signal
  • the WTRU 1120 may use at least the codeword blocklength and the target BLER or range to determine the optimized CQI, along with the measured CSI. In addition, when determining the optimized CQI, the WTRU 1120 may also take into account its own capabilities (e.g., channel estimation method, equalizer, analogue-to-digital conversion granularity, channel decoding algorithm, etc.). Once the optimized CQI is determined, the WTRU 1120 may send the optimized CQI as a recommended CQI to the gNB 1110, which may be translated by the gNB 1110 into a recommended MCS. For example, each CQI may be mapped to an MCS in a table. The g B 1 1 10 may then send the final CQI to the WTRU 1 120 over the control channel (e.g., the PDCCH), which is then translated by the WTRU 1 120 into the final MCS, used for receiving the corresponding data transmission.
  • the control channel e.g., the PDCCH
  • the WTRU 1 120 need not wait for the DL transmission parameters to measure the CSI, and that the CSI may be measured prior to receiving the DL transmission parameters. However, the proximity in time in measuring the CSI to receiving the DL transmission parameters may be taken into account to ensure the measured CSI is not out dated. Thus, the WTRU 1 120 may decide to use a previously measured CSI on a condition the DL transmission parameters are received within a predetermined time interval from the time the CSI was measured.
  • the gNB may jointly encode the control information.
  • two encoding schemes may be considered.
  • the individual encoding scheme each type of control information is encoded separately.
  • the number of channel code types be Ni
  • the number of ranges for the codeword blocklength be N 2
  • the number of target BLERs be N 3
  • the choices of other information be N 4 .
  • the gNB 1 1 10 may consider the recommended CQI along with any historical data collected from the WTRU 1 120. For example, the gNB 1 1 10 may consider one or more previously recommended CQIs received from the WTRU 1 120, and determine that the current recommended CQI deviates outside of a normal range from the historical data. Instead, the gNB 1 1 10 may determine that the target BLER is too high for the WTRU 1 120 and may select a more robust CQI (than the recommended CQI) that is mapped to a more robust MCS for the allocated resource.
  • the blocklength may be assigned by the gNB 1 1 10 for a particular set of resources.
  • the blocklength may be assigned on a TTI-by-TTI basis or may be assigned for a chunk of consecutive TTI (e.g., 10 TTI, 100 TTI, or more) for a certain type of traffic.
  • the CQI determination can be performed on a dynamic basis based on the blocklength assignment for a particular (anticipated or scheduled) resource allocation for one or more scheduled DL transmissions.
  • the blocklength may be dynamically adjusted by the gNB 1110 based on certain communication conditions or target performance criteria that may vary for one or more DL data transmissions (e.g., based on a communication type, such as, massive machine-type communication (mMTC) or ultra- reliable and low latency communication (uRLLC)).
  • mMTC massive machine-type communication
  • uRLLC ultra- reliable and low latency communication
  • the WTRU 1120 is configured to determine an optimal
  • CQI as a recommendation to the gNB 1110 and transmit the CQI to the gNB 1110 for processing (i.e., for a final CQI determination/confirmation).
  • the WTRU 1120 may select a CQI based on a threshold test that includes a comparison of the codeword blocklength to one or more thresholds or threshold ranges. For example, the WTRU 1120 may select a first CQI corresponding to a short codeword blocklength if the codeword blocklength received from the network is below a lower threshold.
  • the first CQI may indicate (e.g., implicitly via a CQI-MCS mapping) a more or a most robust MCS among different MCSs available.
  • the WTRU 1120 may select a second CQI corresponding to an intermediary codeword blocklength if the codeword blocklength received from the network is greater than the lower threshold but less than an upper threshold.
  • the second CQI may indicate (e.g., via a CQI-MCS mapping) that an intermediary robust MCS is available among different MCSs.
  • the WTRU 1120 may select a third CQI corresponding to a large codeword blocklength if the codeword blocklength received from the network is greater than the upper threshold.
  • the third CQI may indicate (e.g., via a CQI-MCS mapping) a less robust or a least robust MCS among different MCSs available.
  • the WTRU 1120 may use any number of thresholds and threshold ranges for selecting from any number of available CQI, and that other DL transmission parameters other than or in conjunction with codeword blocklength may be used during the threshold test.
  • the WTRU 1120 may select a CQI based on a threshold test that includes a comparison of a target BLER to one or more thresholds or threshold ranges in a similar manner described above with respect to the codeword blocklength.
  • a CQI corresponding to a more robust MCS may be selected on a condition that the DL transmission has a target BLER below a lower threshold
  • a CQI corresponding to a less robust MCS may be selected on a condition that the DL transmission has a target BLER between the lower threshold and an upper threshold
  • a CQI corresponding to a least robust MCS may be selected on a condition that the DL transmission has a target BLER above the upper threshold.
  • the threshold tests for codeword blocklength and target BLER may be used in combination to select a CQI based on different threshold test combinations. For example, if both the codeword blocklength and the target BLER are below their respective lower thresholds, then a CQI corresponding to the most robust MCS among the MCSs may be selected. Alternatively, if both the codeword blocklength and the target BLER are greater than their respective upper thresholds, then a CQI corresponding to the least robust MCS among the MCSs may be selected. Furthermore, other intermediary (mixed) level variations are possible based on one parameter being less than a threshold and another parameter being above a threshold such that a CQI corresponding to an intermediary robust MCS is selected.
  • MCS Physical channels coding
  • BPSK BPSK
  • QPSK and QAM (e.g., 16QAM, 64QAM, 256QAM, etc.).
  • QPSK 1 bit is sent per transmission
  • QPSK 2 bits are sent per transmission
  • 16QAM 4 bits are sent per transmission
  • 64QAM 6 bits are sent per transmission
  • 256QAM 8 bits are sent per transmission.
  • BPSK is more robust than QPSK
  • QPSK is more robust than QAM
  • 16QAM is more robust than 256QAM, and so on.
  • the WTRU 1120 may receive multiple target BLERs or multiple target BLER ranges, and perform a CQI selection, based also on measured CSI, for each of the multiple target BLERs or each of the multiple target BLER ranges. The WTRU 1120 may then feed back the multiple CQIs to the g B 11 10.
  • the WTRU 1120 may further provide association information (e.g., an indication or a mapping) for associating a particular CQI to one of the multiple target BLERs or multiple target BLER ranges.
  • association information e.g., an indication or a mapping
  • the WTRU 1120 may link each CQI to one of the multiple target BLERs or one of the multiple target BLER ranges, and the gNB 1110 may determine the association via the association information provided by the WTRU 1120.
  • two or more CQIs may be determined by the WTRU 1120, one for each target BLER or each target BLER range, and transmitted to the gNB 1110.
  • the gNB 1110 may then determine which CQI to use or which CQI to consider for its final CQI determination based on a BLER of a scheduled data transmission. Therefore, the g B 1110 may determine a BLER for a next transmission, select a CQI from the multiple CQIs received from the WTRU 1120 based on a match to the BLER for a next transmission, and apply an MCS corresponding to the selected CQI.
  • the CQIs provided by the WTRU 1120 for multiple target BLER or BLER ranges may be applied over multiple DL data transmissions on a dynamic basis based on a BLER of an upcoming (i.e., next) DL data transmission.
  • the gNB 1110 informs the gNB 1110
  • WTRU 1120 of the final determined CQI to be used for the data transmission from which the WTRU 1120 can interpret the MCS to be applied for receiving the data transmission. It will also be appreciated that multiple tiers of BLER thresholds may be used for selecting among multiple CQIs.
  • the WTRU 1120 may receive multiple target codeword blocklengths or multiple target codeword blocklength ranges, and perform a CQI selection, based also on measured CSI, for each of the multiple target codeword blocklengths or each of the multiple target codeword blocklength ranges. The WTRU 1120 may then feed back the multiple CQIs to the network. The WTRU 1120 may further provide association information (e.g., an indication or a mapping) for associating a particular CQI to one of the multiple target codeword blocklengths or multiple target codeword blocklength ranges. Thus, the WTRU 1120 may link each CQI to one of the multiple target codeword blocklengths or one of the multiple target codeword blocklength ranges, and the gNB 1110 may determine the association via the association information provided by the WTRU 1120.
  • association information e.g., an indication or a mapping
  • Codeword blocklength ranges may be, for example, for any packet or transport block below a block size threshold (e.g., 100 bits) or equal to and above the block size threshold.
  • a block size threshold e.g. 100 bits
  • two (or more) CQIs may be determined by the WTRU 1120 and transmitted to the gNB 1110. The gNB 1110 may then determine which CQI to use or which to consider for its final CQI determination based on a codeword blocklength of a scheduled data transmission.
  • the gNB 1110 may determine a codeword blocklength for a next transmission, select a CQI from the multiple CQIs received from the WTRU 1120 based on a match to the codeword blocklength for a next transmission, and apply an MCS corresponding to the selected CQI.
  • the CQIs provided by the WTRU for multiple targets and ranges may be applied over multiple DL data transmissions on a dynamic basis based on a codeword blocklength of an upcoming (i.e., next) DL data transmission.
  • the g B 1110 informs the
  • WTRU 1120 of the final determined CQI to be used for the data transmission from which the WTRU 1120 can interpret the MCS to be applied for receiving the data transmission. It will also be appreciated that multiple tiers of block size thresholds may be used for selecting among multiple CQIs.
  • each of the multiple target BLERs or multiple target BLER ranges may be applied to a codeword blocklength, such that the WTRU receives a single codeword blocklength along with the multiple target BLERs or multiple target BLER ranges for determining the multiple CQIs.
  • each of the multiple target codeword blocklengths or multiple target codeword blocklength ranges may be applied to a target BLER, such that the WTRU receives a single target BLER along with the multiple target codeword blocklengths or multiple target codeword blocklength ranges for determining the multiple CQIs.
  • multiple target BLERs or multiple target BLER ranges may be used in combination with multiple target codeword blocklengths or multiple target codeword blocklength ranges for determining the multiple CQIs.
  • the gNB 1110 may use the CQIs and one or more transmission parameters of an upcoming DL data transmission to select a CQI for the upcoming DL data transmission.
  • the WTRU 1120 may also transmit mapping information to the gNB 1110, along with the CQIs, to indicate which CQI corresponds to a specific target BLER and/or target codeword blocklength.
  • FIG. 12 illustrates a flow diagram of a CQI feedback procedure 1200 implemented by a WTRU according to one or more embodiments.
  • the CQI feedback procedure 1200 includes, receiving target performance criteria (e.g., channel code type, a codeword blocklength, and/or a target BLER) (operation 1205) and determining a CQI that is optimized according to the received target performance criteria (operation 1210). Once the CQI is determined, the determined CQI is fed back to the network (operation 1215), and a final CQI from the network is received (operation 1220).
  • target performance criteria e.g., channel code type, a codeword blocklength, and/or a target BLER
  • the network e.g., e B or gNB
  • the network determines the MCS and the resource allocation for the WTRU
  • the network may still need to take into account the impact of a finite/short blocklength on the performance of the channel code.
  • Equations (1), (9), (10), and (11) are still applicable, in addition to Equation (12) discussed below.
  • the MCS and maximum HARQ rounds may be adapted to QoS requirements while considering the effect of the codeword blocklength, and may be applied to any of the embodiments discussed herein.
  • the MCS (with the consideration of the codeword blocklength) and the maximum HARQ rounds may be adapted to meet the QoS requirements (e.g., target BLER and delay) of a variety of traffic types.
  • the eNB or gNB may need to serve different types of traffic with different QoS requirements.
  • one traffic type may be for remote robotic control, which requires ultra-high reliability and ultra-low delay
  • another traffic type may be for Hypertext Transfer Protocol (HTTP) web access, which has very relaxed requirements on reliability or delay.
  • HTTP Hypertext Transfer Protocol
  • the robotic control traffic may be assigned a very robust MCS that eliminates the need for retransmissions and achieves lxlO "6 BLER, while the HTTP web traffic may be assigned a less robust MCS that achieves lxlO "2 BLER and assigned a maximum number of retransmissions of 4.
  • the MCS used to achieve a preset link performance depends on the blocklength, for example, as shown in Equations (1) and (9).
  • a transmitter may use the CSI feedback from the receiver to read out or estimate the effective SINRs at the receiver. Inserting the effective SINRs into Equation (9) may provide the maximum rate R * (nl, ⁇ , fi, yi) as a function of n, I, and ⁇ , where n is the blocklength, / is the number of parallel AWGN channels, and ⁇ is the frame error probability.
  • the transmitter can set ⁇ to the target BLER, and determine the values of n or / based on the available resources and the amount of data to serve, which in turn determine R*, which in turn determines the coding rate.
  • R* which in turn determines the coding rate.
  • the average HARQ rate may be defined as the effective coding rate at HARQ round 1 (i.e., the mother code rate divided by the number of HARQ rounds), denoted by R, divided by the average number of HARQ rounds per message (i.e., per HARQ transmission) denoted by E[L HARQ (i?)], where E[L HARQ (i?)] is a function of the coding rate R :
  • the coding rate and the average communication rate are identical. If there is a constraint on the BLER the maximum rate may occur at the boundary of the region of feasible rates. In other words, coding rate may be increased until the BLER constraint is satisfied with an equality.
  • the average communication rate is the coding rate divided by the average number of HARQ rounds, which may increase with the coding rate. For this reason, increasing the coding rate within the feasible range of coding rates may not necessarily increase the average communication rate. It is possible that the increase in the average number of HARQ rounds has a larger negative effect than the increase in the coding rate.
  • FIG. 13 is a graph illustrating an average hybrid automatic repeat request
  • HARQ block error rate
  • FIG. 13 is a graph illustrating an average HARQ rate (in bits/symbol) as a function of the mother code coding rate R/2 (in bits/symbol) for a BLER constraint of 10 "2 according to one or more embodiments.
  • the coding rate values shown in FIG. 13 are feasible, i.e., with these rates the HARQ system satisfies the BLER constraint of l .OxlO "2 .
  • the modulation scheme may be QPSK
  • the mother code length may be 1024 QPSK symbols (2048 bits)
  • the average SNR may be 10 dB.
  • the capacity of the GOOD state may be approximately 1 while the capacity of the BAD state may be approximately 0.6 (the capacity values are actually 2 and 1.2 but because the mother code rate may be over two rounds it makes sense to use 1 and 0.6 for a comparison with the mother code rate).
  • the results may be a HARQ process that never goes to round 2, and a fixed blocklength system is achieved. Accordingly, the average HARQ rate increases linearly with the coding rate.
  • the behavior may be different. For example, when a rate meets this criteria, the HARQ system always goes to round 2 if it starts in the BAD state, and never goes to round 2 if it starts in the GOOD state. It follows that in this region the average number of HARQ rounds may be constant and, as the coding rate is increased, the average HARQ rate increases linearly as well.
  • the HARQ system begins to go to round 2 even if it starts in the GOOD state.
  • a local maximum/global maximum may be observed. Again above this local maximum, the effect of the rate on the average number of HARQ rounds offset the incremental rate increase.
  • a mother code that is slightly less than 1 bits/symbol e.g., 0.9-0.95 bits/symbol
  • a mother code around 0.5 bits/symbol may be a better choice.
  • the transmitter may leverage the ACK/NACK received for previous transmissions to predict the channel state for the upcoming transmission. For example, the transmitter may consider whether an ACK or a NACK was received for a previous transmission, or a number of NACKs received before an ACK was received via multiple rounds of HARQ feedback. In addition, for different traffic types, the transmitter may choose different target BLERs, using the MCS chosen and ACK/NACK historical information for a previous transmission, and possibly combining these information with some theoretical/empirical model.
  • the feeding back of CSI takes the effect of infinite blocklength for carrying multiple transport blocks within one TTI in a single layer/stream into account. This concept extends aspects of embodiments discussed above.
  • the network may need to deliver different types of traffic to the same WTRU that have drastically different QoS requirements.
  • an e B delivers both video and commands (for video rendering) to a WTRU.
  • Both traffic types require stringent latency, but differ in the reliability requirements.
  • a BLER of lxlO "3 may be good enough, while for commands, a BLER of lxlO "5 may be needed. Due to similar latency requirements, it may be preferable to serve both traffic types in the same TTI rather than to serve the one traffic type in one TTI and then serve the other traffic type in the next TTI.
  • the distinct BLER requirements means that there may be a significant difference in spectral efficiency (i.e., the coding rate for commands should be much lower than that for video).
  • a reasonable approach may be to have two transport blocks in the same TTI: one for video and the other for commands, where the two transport blocks are delivered with different MCS.
  • This approach may reduce latency for multiplexed low latency traffic streams and may improve spectral efficiency because the same MCS for all RBs allocated to a single TTI may not be efficient.
  • the channel state feedback described previously may be modified to account for the need of reporting the MCS that targets different link performance, e.g., different BLER.
  • the WTRU may receive multiple target BLER or multiple target BLER ranges, and provide CSI and CQI for each BLER target parameter.
  • FIG. 14 is a timing diagram that shows CQI feedback procedure 1400 for multiple BLERs for transmitting multiple transport blocks in one transmitting time interval (TTI) in a single layer/stream, with multiple CQIs for each target BLER.
  • TTI time interval
  • FIG. 14 shows how the embodiment shown in FIG. 8 may be adapted to accommodate transmitting multiple transport blocks in one TTI in a single layer/stream.
  • FIG. 14 further illustrates the possibility of two target BLERs, referred to as BLER 1 and BLER 2. For each target BLER value, multiple CQI values are provided, each one corresponding to a blocklength range.
  • WTRU k Prior to a data transmission at 1405, WTRU k determines two CQIs for each target BLER, and sends the CQIs to the e B, along with information that indicates to which blocklength range each CQI corresponds.
  • Each blocklength range 1, 2, 3 and 4 may be different, or arranged in pairs such that, for example, blocklength range 1 and 3 are the same and blocklength range 2 and 4 are the same.
  • each target BLER and blocklength range may be provided to the WTRU k via control information received from the eNB.
  • the eNB may not need to notify the eNB
  • the eNB may determine a blocklength based on the data, determine a BLER based on the traffic type of the data, and determine a final CQI/MCS by referring to a CQI among the multiple CQIs received from WTRU k.
  • the CQI selected is the CQI that corresponds to the blocklength range that contains the determined blocklength and has a BLER that matches the determined BLER.
  • the eNB sends resource assignment information, the MCS and the data to WTRU k.
  • the control information including resource allocation and the final CQI or MCS, is sent at the beginning of a TTI, and the data follows but still in the same TTI.
  • FIG. 15 is a timing diagram that shows a procedure 1500 for feeding back blocklength-specific CQFs for different target BLER's for transmitting multiple transport blocks in one TTI in one layer/stream.
  • FIG. 15 shows an example, where two transport blocks that have different TBS and target BLERs are implemented.
  • data unit 1 and data unit 2 arrive at the eNB, respectively, and, based on each data unit, the eNB may determine a TBS and a BLER for each data unit 1 and 2.
  • the eNB sends the determined TBS (e.g., TBS 1 and TBS 2) and the determined BLER (e.g., BLER 1 and BLER 2) to WTRU k.
  • BLER 1 and TBS 2 Upon receiving the TBS 1, BLER 1 and TBS 2, BLER 2, WTRU k determines the blocklength-specific CQI (i.e., corresponding to an MCS) needed for the eNB to deliver the data with a target performance, and sends each blocklength-specific CQI for each parameter pair (e.g., CQI for data unit 1 and CQI for data unit 2) to the eNB at 1520.
  • blocklength-specific CQI i.e., corresponding to an MCS
  • the eNB Upon receiving the blocklength-specific CQIs from transmission 1520, the eNB processes the blocklength-specific CQIs, determines final, network-based CQIs, and determines an MCS that corresponds to each of the final, network-based CQIs based on CQI-MCS mapping information (e.g., CQI-MCS table). The eNB also determines a resource allocation needed to serve the amount of data for data unit 1 and data unit 2. At 1525, the eNB transmits the MCS and the resource allocation information for data unit 1 and the MCS and the resource allocation information for data unit 2 to WTRU k. Finally, at 1530, after n TTFs the eNB transmits the data (data unit 1 and data unit 2) to WTRU k.
  • CQI-MCS mapping information e.g., CQI-MCS table
  • LTE/LTE-A standards such as, but not limited to: for resource allocation, the DCI format now may need to specify not only which WTRU a resource block (RB) may be mapped to, but also which transport block (TB) of that WTRU the RB would be mapped to; the DCI format may need to specify the TBS for each of the TBs; the DCI format may need to contain multiple MCS values from the eNB to the WTRU in a single TTI; and, for power control, the TB with higher reliability (e.g., lower BLER) requirement may be allocated more power than transport blocks with lower reliability (e.g., higher BLER).
  • RB resource block
  • TB transport block
  • the codeword blocklength may be a consideration in determining the codeword blocklength
  • Equation (1) may be used for different types of traffic having different BLER requirements, say, Sj and ⁇ 2 .

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

Abstract

L'invention concerne des procédés, des appareils et des systèmes pour déterminer un indicateur de qualité du canal (CQI) et régler un mécanisme de modulation et de codage (MCS) pour une transmission de liaison descendante (DL). Plus particulièrement, un procédé mis en œuvre dans une unité d'émission/réception sans fil (WTRU) comprend la réception d'informations de commande, comprenant une longueur de bloc de mot de code et un paramètre de BLER cible pour la transmission DL, la mesure d'informations d'état de canal (CSI), la détermination d'un CQI fondé sur la WTRU en fonction des CSI mesurées, de la longueur de bloc de mot de code et du paramètre de BLER cible et la transmission du CQI fondé sur la WTRU à une station de base. Le procédé comprend en outre la réception d'un CQI fondé sur un réseau pour la transmission DL, le CQI fondé sur un réseau étant dérivé du CQI fondé sur la WTRU, la détermination d'un MCS en fonction du CQI fondé sur un réseau et la réception de la transmission DL à l'aide du MCS déterminé.
PCT/US2017/049039 2016-08-29 2017-08-29 Procédés de codage de longueur de bloc finie dans des systèmes de communication sans fil WO2018044849A1 (fr)

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CN113766425A (zh) * 2021-09-26 2021-12-07 深圳金信诺高新技术股份有限公司 一种网络传输性能调节方法
CN113905446A (zh) * 2020-06-22 2022-01-07 中国移动通信有限公司研究院 一种下行调制编码方式估计方法、装置及网络设备
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WO2024016898A1 (fr) * 2022-07-20 2024-01-25 大唐移动通信设备有限公司 Procédé de transmission d'informations, appareil, dispositif de réseau et terminal

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Cited By (31)

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Publication number Priority date Publication date Assignee Title
WO2018127765A1 (fr) * 2017-01-06 2018-07-12 Telefonaktiebolaget Lm Ericsson (Publ) Signalement d'indicateurs de qualité de canal correspondant à des taux d'erreur cibles dans des réseaux de communication sans fil
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US11108526B2 (en) 2018-04-02 2021-08-31 Qualcomm Incorporated Channel quality indicator (CQI) reporting for ultra-reliable low latency communications (URLLC)
WO2019195161A1 (fr) * 2018-04-02 2019-10-10 Qualcomm Incorporated Notification d'indicateur de qualité de canal (cqi) pour des communications à faible latence ultra-fiables (urllc)
US11728952B2 (en) 2018-04-02 2023-08-15 Qualcomm Incorporated Channel quality indicator (CQI) reporting for ultra-reliable low latency communications (URLLC)
CN111919412B (zh) * 2018-04-02 2023-10-27 高通股份有限公司 用于超可靠低时延通信（urllc）的信道质量指示符（cqi）报告的方法和设备
US11469810B2 (en) * 2018-04-02 2022-10-11 Datang Mobile Communications Equipment Co., Ltd. Channel quality indicator sending method, and data sending method and device
CN111919412A (zh) * 2018-04-02 2020-11-10 高通股份有限公司 用于超可靠低时延通信（urllc）的信道质量指示符（cqi）报告
US10797774B2 (en) 2018-05-11 2020-10-06 Qualcomm Incorporated Ultra-reliable low latency communication with multiple transmission-reception points
CN112088518B (zh) * 2018-05-11 2022-03-08 高通股份有限公司 用于具有多个发送接收点的超可靠低延时通信的方法、装置
CN112088518A (zh) * 2018-05-11 2020-12-15 高通股份有限公司 具有多个发送接收点的超可靠低延时通信
WO2019217702A1 (fr) * 2018-05-11 2019-11-14 Qualcomm Incorporated Communication ultra-fiable à faible latence avec de multiples points de transmission-réception
US11705951B2 (en) 2018-05-11 2023-07-18 Qualcomm Incorporated Ultra-reliable low latency communication with multiple transmission-reception points
US11190258B2 (en) 2018-05-11 2021-11-30 Qualcomm Incorporated Ultra-reliable low latency communication with multiple transmission-reception points
US10715275B2 (en) 2018-05-11 2020-07-14 At&T Intellectual Property I, L.P. Configuring channel quality indicator for communication service categories in wireless communication systems
US11218245B2 (en) 2018-05-11 2022-01-04 At&T Intellectual Property I, L.P. Configuring channel quality indicator for communication service categories in wireless communication systems
CN114531217A (zh) * 2018-05-11 2022-05-24 高通股份有限公司 用于具有多个发送接收点的超可靠低延时通信的方法、装置
CN114531217B (zh) * 2018-05-11 2023-09-19 高通股份有限公司 用于具有多个发送接收点的超可靠低延时通信的方法、装置
US10492212B1 (en) 2018-06-22 2019-11-26 At&T Intellectual Property I, L.P. Scheduling ultra-reliable low latency communications in wireless communication systems
US11191089B2 (en) 2018-06-22 2021-11-30 At&T Intellectual Property I, L.P. Scheduling ultra-reliable low latency communications in wireless communication systems
CN113056882A (zh) * 2018-09-07 2021-06-29 三星电子株式会社 在无线通信系统中使用多个mcs的数据通信方法和设备
KR102648869B1 (ko) * 2018-09-07 2024-03-19 삼성전자주식회사 무선 통신 시스템에서 다중 mcs를 이용한 데이터 통신 방법 및 장치
KR20200028787A (ko) * 2018-09-07 2020-03-17 삼성전자주식회사 무선 통신 시스템에서 다중 mcs를 이용한 데이터 통신 방법 및 장치
EP3843302A4 (fr) * 2018-09-07 2021-10-27 Samsung Electronics Co., Ltd. Procédé et dispositif de communication de données utilisant un mcs multiple dans un système de communication sans fil
CN113905446A (zh) * 2020-06-22 2022-01-07 中国移动通信有限公司研究院 一种下行调制编码方式估计方法、装置及网络设备
US20230059139A1 (en) * 2021-08-16 2023-02-23 Qualcomm Incorporated Multiple data channel based channel state information reports
WO2023022808A1 (fr) * 2021-08-16 2023-02-23 Qualcomm Incorporated Rapports d'informations d'état de canal reposant sur des canaux de données multiples
US11909681B2 (en) * 2021-08-16 2024-02-20 Qualcomm Incorporated Multiple data channel based channel state information reports
CN113766425B (zh) * 2021-09-26 2023-10-27 深圳金信诺高新技术股份有限公司 一种网络传输性能调节方法
CN113766425A (zh) * 2021-09-26 2021-12-07 深圳金信诺高新技术股份有限公司 一种网络传输性能调节方法
WO2024016898A1 (fr) * 2022-07-20 2024-01-25 大唐移动通信设备有限公司 Procédé de transmission d'informations, appareil, dispositif de réseau et terminal

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