Simultaneous multi-panel transmission of multiple codewords

Abstract

1. A method performed by a base station (BS) in a radio access network (RAN), the method including: receiving uplink (UL) reference signals (RS) transmitted from each of a plurality of transmit / receive points (TRPs), each UL RS being received at each of the plurality of TRPs from each of a plurality of panels; determining a channel quality indicator (CQI) for each of the received UL RSs; selecting a respective panel from the plurality of panels for each of the plurality of TRPs based on the determined CQI for each of the received UL RSs; and transmitting a codeword and the determined respective panel for each of the plurality of TRPs, the codeword for each of the plurality of TRPs having a priority based on the determined CQI for each of the received UL RSs.

Description

[Technical Field]

[0001] (CROSS-REFERENCE TO RELATED APPLICATIONS) This application claims the benefit of U.S. Provisional Patent Application No. 63 / 388,045, filed July 11, 2022, the entire contents of which are incorporated herein by reference. [Background technology]

[0002] The present disclosure relates generally to panel transmission, and more particularly to simultaneous multi-panel transmission using multiple codewords (CWs).

[0003] Mobile communication systems have been designed to provide voice services while guaranteeing user activity. However, the coverage of mobile communication services is expanding to include data services in addition to voice services. The rapid increase in traffic may result in resource shortages and user demand for high-speed services that require advanced mobile communication systems. Requirements for next-generation mobile communication systems may include a significant increase in each user's transmission rate and data traffic, a significant increase in the number of connected devices, the need for low end-to-end delay time, and support for high energy efficiency.

[0004] Improved 5G or pre-5G communication systems that meet these requirements need to be developed. Therefore, 5G or pre-5G communication systems may be referred to as "beyond 4G networks" or "post-LTE systems." Due to higher data rates, 5G communication systems may be implemented in higher frequency (millimeter wave) bands, such as the 60 GHz band. 5G communication systems may implement beamforming, massive multiple-input multiple-output (MIMO), full-dimensional MIMO (FD-MIMO), array antennas, analog beamforming, and large-scale antenna technologies to help reduce radio wave propagation loss and increase transmission distance. Further developments in 5G communication systems may include advanced small cells, cloud radio access networks (RANs), ultra-dense networks, device-to-device (D2D) communications, wireless backhaul, mobile networks, cooperative communications, coordinated multipoint (CoMP), and receiver-end interference cancellation. 5G communication systems may implement hybrid FSK and QAM modulation (FQAM) and sliding window superposition coding (SWSC) as advanced coding modulation (ACM). Furthermore, as advanced access technologies are developed, 5G communication systems may also implement filter bank multi-carrier (FBMC), non-orthogonal multiple access (NOMA), and sparse code multiple access (SCMA). Summary of the Invention

[0005] Methods, systems, and apparatus are provided for receiving retransmissions of transport blocks (TBs) (e.g., codewords) with different priorities through panels and / or transmit / receive points (TRPs) different from those originally scheduled.

[0006] The wireless transmit / receive unit may include a processor. The processor may be configured to receive configuration information indicating one or more rules for determining a panel from among a plurality of panels to be used for receiving a retransmitted codeword. The processor may be further configured to measure downlink (DL) reference signals (RS) transmitted from each of a plurality of transmission / reception points (TRPs), wherein a respective DL RS is received from each of the plurality of TRPs via a panel from the plurality of panels. The processor may be further configured to select a respective TRP for each of the plurality of panels based on the measured DL RS. The processor may be further configured to send feedback indicating the respective TRP selected for each of the plurality of panels, and channel quality indication (CQI) feedback is provided for each combination of the plurality of TRPs and the plurality of panels. The processor may be further configured to receive at least a first codeword from a first TRP from the plurality of TRPs via a first panel from the plurality of panels and a second codeword from a second TRP from the plurality of TRPs via a second panel from the plurality of panels. The processor may be further configured to determine, based on the first codeword being a higher priority than the second codeword and based on one or more rules indicated by the configuration information, that a retransmission of the first codeword from the first TRP should be received via the second panel. The processor may be further configured to receive a retransmission of the first codeword from the first TRP via the second panel.

[0007] The processor may be further configured to receive information indicating an association between each of the plurality of TRPs and each of the plurality of panels, a priority of each TRP-panel association, a modulation and coding scheme (MCS) for each TRP-panel association, or resources used for each TRP-panel association.

[0008] The one or more rules may indicate whether the WTRU is configured for retransmission without downlink control information (DCI) or retransmission with DCI, whether the WTRU should send an acknowledgment (ACK) message for a received codeword, or the number of CQI reports configured per panel of multiple panels.

[0009] The feedback may indicate that the CQI associated with the combination of the first TRP and the first panel is stronger than any other combination of multiple TRPs and multiple panels.

[0010] The processor may be further configured to determine that a retransmission of the first codeword should be received from the first TRP via the second panel based on a CQI associated with a combination of the second TRP and the second panel that is stronger than any other combination of the plurality of TRPs and the plurality of panels except for an association of the first TRP with the first panel.

[0011] The processor may be further configured to review an indication that a retransmission of the first codeword should be received from the first TRP via the second panel.

[0012] The processor may be further configured to detect that a failure occurs when attempting to receive the first codeword from the first TRP via the first panel, and to transmit a negative acknowledgment (NACK) in response to the failure before determining that a retransmission of the first codeword from the first TRP should be received via the second panel.

[0013] The processor may be further configured to detect that a failure occurs when attempting to receive the first codeword from the first TRP via the first panel, send updated CQI feedback for each combination of the plurality of TRPs and the plurality of panels, and receive information indicating an updated association between each of the plurality of TRPs and each of the plurality of panels.

[0014] The processor may be further configured to determine that the CQI feedback provided to each TRP and associated panel meets a block error rate (BLER) threshold.

[0015] The method may be performed by a base station (BS) in a radio access network (RAN). The method may comprise receiving uplink (UL) reference signals (RS) transmitted from each of a plurality of transmission / reception points (TRPs), wherein a respective UL RS is received at each of the plurality of TRPs from each of a plurality of panels. The method may further comprise determining a channel measuring indicator (CQI) for each of the received UL RSs. The method may further comprise selecting a respective panel from the plurality of panels for each of the plurality of TRPs based on the determined CQI for each of the received UL RSs. The method may further comprise transmitting a codeword and the determined respective panel for each of the plurality of TRPs, wherein the codeword for each of the plurality of TRPs has a priority based on the determined CQI for each of the received UL RSs. [Brief explanation of the drawings]

[0016] [Figure 1A] FIG. 1 is a system diagram illustrating an example communication system in which one or more disclosed embodiments may be implemented. [Figure 1B] 1B is a system diagram illustrating an exemplary wireless transmit / receive unit (WTRU) that may be used within the communication system illustrated in FIG. 1A, according to one embodiment. [Figure 1C] 1A is a system diagram illustrating an example radio access network (RAN) and an example core network (CN) that may be used within the communication system illustrated in FIG. 1A, according to one embodiment. [Figure 1D] 1B is a system diagram illustrating a further exemplary RAN and a further exemplary CN that may be used within the communication system illustrated in FIG. 1A, according to one embodiment. [Figure 2] FIG. 1 illustrates an exemplary multiple transmission / reception point (mTRP) uplink (UL) scheme. [Figure 3] 1 is an example of a modulation and coding scheme (MCS) index table for a physical downlink channel (PDSCH). [Figure 4] 1 is an example of a 4-bit bit-width channel quality indicator (CQI) table. [Figure 5] FIG. 1 illustrates an exemplary panel-to-TRP association, including four panels and three transmission / reception points (TRPs). [Figure 6] FIG. 1 illustrates exemplary panel and TRP associations, including four panels and five TRPs. [Figure 7] FIG. 1 illustrates exemplary panel and TRP associations for a single CW of four panels and three TRPs. [Figure 8] FIG. 10 illustrates how to obtain a single CQI value for a single CW for all panels. [Figure 9] FIG. 10 is a procedural diagram illustrating an exemplary panel and TRP association for a downlink (DL) channel. [Figure 10] FIG. 10 is a procedural diagram illustrating an exemplary panel and TRP association for an uplink (UL) channel. [Figure 11] FIG. 10 is a flowchart illustrating an example process for bitwidth reduction based on calculated CQI / MCS values. [Figure 12] FIG. 10 is a procedure diagram illustrating an exemplary panel and TRP association for a DL channel based on priority. [Figure 13]FIG. 10 is a procedure diagram illustrating an exemplary panel and TRP association for UL channels based on priority. [Figure 14] 1 is a table illustrating an exemplary assignment of priorities to transport blocks (TBs). [Figure 15] 10 is a table illustrating an exemplary assignment of MCS indices to CWs. [Figure 16] 10 is a table illustrating an exemplary association of TB to CW. [Figure 17] FIG. 10 is a flowchart illustrating an exemplary process for retransmission on a different panel. DETAILED DESCRIPTION OF THE INVENTION

[0017] 1A is a diagram illustrating an example communication system 100 in which one or more disclosed embodiments may be implemented. Communication system 100 may be a multiple-access system that provides content, such as voice, data, video, messaging, broadcasts, etc., to multiple wireless users. Communication system 100 may enable multiple wireless users to access such content through sharing of system resources, including wireless bandwidth. For example, the communication system 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 DFT-Spread OFDM (ZT UW DTS-s OFDM), unique word OFDM (UW-OFDM), resource block filtered OFDM, filter bank multicarrier (FBMC), etc.

[0018] 1A, communications system 100 may include wireless transmit / receive units (WTRUs) 102a, 102b, 102c, 102d, RANs 104 / 113, CNs 106 / 115, public switched telephone network (PSTN) 108, the Internet 110, and other networks 112, although it will be understood that the disclosed embodiments contemplate any number of WTRUs, base stations, networks, and / or network elements. Each of WTRUs 102a, 102b, 102c, 102d may be any type of device configured to operate and / or communicate in a wireless environment. By way of example, the WTRUs 102a, 102b, 102c, 102d, any of which may be referred to as a "station" and / or "STA," may be configured to transmit and / or receive wireless signals and may include user equipment (WTRU), a mobile station, a fixed or mobile subscriber unit, a subscription-based unit, a pager, a cellular phone, 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, medical devices and applications (e.g., remote surgery), industrial devices and applications (e.g., robots and / or other wireless devices operating in industrial and / or automated processing chain situations), consumer electronics devices, devices operating on commercial and / or industrial wireless networks, etc. Any of the WTRUs 102a, 102b, 102c, 102d may be referred to interchangeably as a WTRU.

[0019] 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 communications networks, such as the CN 106 / 115, the Internet 110, and / or other networks 112. By way of example, the base stations 114a, 114b may be a base transceiver station (BTS), a Node B, an eNodeB, a Home Node B, a Home eNodeB, a gNB, an NR Node B, a site controller, an access point (AP), a wireless router, etc. Although the base stations 114a, 114b are each depicted as a single element, it will be understood that the base stations 114a, 114b may include any number of interconnected base stations and / or network elements.

[0020] 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. The base station 114a and / or base station 114b may be configured to transmit and / or receive radio signals on one or more carrier frequencies, which may be referred to as a cell (not shown). These frequencies may be licensed spectrum, unlicensed spectrum, or a combination of licensed and unlicensed spectrum. A cell may provide wireless service coverage for a particular geographic area, which may be relatively fixed or may change over time. A cell may be further divided into cell sectors. For example, the cell associated with the base station 114a may be divided into three sectors. Thus, in one embodiment, the base station 114a may include three transceivers, i.e., one transceiver for each sector of the cell. In one embodiment, the base station 114a may employ multiple-input multiple output (MIMO) technology and may utilize multiple transceivers per sector of the cell, for example, using beamforming to transmit and / or receive signals in desired spatial directions.

[0021] The base stations 114a, 114b may communicate with one or more of the WTRUs 102a, 102b, 102c, 102d over an air interface 116, which may be any suitable wireless communication link (e.g., radio frequency (RF), microwave, centimeter wave, micrometer wave, infrared (IR), ultraviolet (UV), visible light, etc.). The air interface 116 may be established using any suitable radio access technology (RAT).

[0022] More specifically, as noted above, the communications system 100 may be a multiple-access system, but may employ one or more channel access schemes, such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA, etc. For example, the base station 114 a and the WTRUs 102 a, 102 b, 102 c in the RAN 104 / 113 may implement a radio technology such as Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access (UTRA), which may establish the air interface 115 / 116 / 117 using wideband CDMA (WCDMA). WCDMA may include communications 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 Packet Access (HSUPA).

[0023] In one embodiment, 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 the air interface 116 using Long Term Evolution (LTE) and / or LTE-Advanced (LTE-Advanced, LTE-A) and / or LTE-Advanced Pro (LTE-Advanced Pro, LTE-A Pro).

[0024] In one embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement a radio technology such as NR radio access, which may establish the air interface 116 using New Radio (NR).

[0025] In one embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement multiple radio access technologies. For example, the base station 114a and the WTRUs 102a, 102b, 102c may jointly implement LTE radio access and NR radio access, e.g., using dual connectivity (DC) principles. Thus, the air interface utilized by the WTRUs 102a, 102b, 102c may be characterized by multiple types of radio access technologies and / or transmissions to and from multiple types of base stations (e.g., eNBs and gNBs).

[0026] In other embodiments, the base station 114a and the WTRUs 102a, 102b, 102c may implement a wireless technology such as IEEE 802.11 (i.e., Wireless Fidelity, WiFi), IEEE 802.16 (i.e., Worldwide Interoperability for Microwave Access, WiMAX), CDMA2000, CDMA2000 1X, CDMA2000 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), or the like.

[0027] 1A may be, for example, a wireless router, a Home NodeB, a Home eNodeB, or an access point and may utilize any suitable RAT to facilitate wireless connectivity in a local area such as a business, a home, a vehicle, a campus, an industrial facility, an air corridor (e.g., for use by drones), a road, etc. In one embodiment, 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). In one embodiment, 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). In yet another embodiment, 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 a femtocell. As shown in FIG. 1A, the base station 114b may have a direct connection to the Internet 110. Thus, the base station 114b may not need to access the Internet 110 through the CN 106 / 115.

[0028] The RAN 104 / 113 may communicate with the CN 106 / 115, which may be any type of network configured to provide voice, data, application, and / or voice over internet protocol (VoIP) services to one or more of the WTRUs 102a, 102b, 102c, 102d. The data may have various quality of service (QoS) requirements, such as different throughput, latency, error tolerance, reliability, data throughput, mobility, etc. 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. Although not shown in FIG. 1A , it will be understood that the RAN 104 / 113 and / or the CN 106 / 115 may communicate directly or indirectly with other RANs employing the same RAT as the RAN 104 / 113 or a different RAT. For example, in addition to being connected to the RAN 104 / 113, which may utilize NR radio technology, the CN 106 / 115 may also communicate with another RAN (not shown) employing GSM, UMTS, CDMA2000, WiMAX, E-UTRA, or WiFi radio technology.

[0029] The CN 106 / 115 may also serve as a gateway for the WTRUs 102a, 102b, 102c, 102d to access the PSTN 108, the Internet 110, and / or other networks 112. The PSTN 108 may include a circuit-switched telephone network providing plain old telephone service (POTS). The Internet 110 may include a global system of interconnected computer networks and devices, which use common communication protocols such as the transmission control protocol (TCP), the user datagram protocol (UDP), and / or the internet protocol (IP) of the TCP / IP Internet protocol suite. The network 112 may include wired and / or wireless communication networks owned and / or operated by other service providers. For example, the network 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.

[0030] 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.) For example, the WTRU 102c shown in FIG. 1A may be configured to communicate with a base station 114a, which may employ a cellular-based wireless technology, and a base station 114b, which may employ an IEEE 802.2 wireless technology.

[0031] 1B is a system diagram illustrating an example WTRU 102. As shown in FIG. 1B, the WTRU 102 may include, among other things, 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. It will be understood that the WTRU 102 may include any sub-combination of the foregoing elements while remaining consistent with an embodiment.

[0032] The processor 118 may be a general-purpose processor, a special-purpose processor, a conventional processor, a digital signal processor (DSP), multiple microprocessors, one or more microprocessors associated with a DSP core, a controller, a microcontroller, an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA) circuit, any other type of integrated circuit (IC), a state machine, etc. 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. 1B depicts the processor 118 and the transceiver 120 as separate components, it will be understood that the processor 118 and the transceiver 120 may be integrated together in an electronic package or chip.

[0033] The transmit / receive element 122 may be configured to transmit or receive signals to or from a base station (e.g., base station 114a) over the air interface 116. For example, in one embodiment, the transmit / receive element 122 may be an antenna configured to transmit and / or receive RF signals. In one embodiment, the transmit / receive element 122 may be an emitter / detector configured to transmit and / or receive IR signals, UV signals, or visible light signals, for example. In another embodiment, the transmit / receive element 122 may be configured to transmit and / or receive both RF signals and light signals. It will be understood that the transmit / receive element 122 may be configured to transmit and / or receive any combination of wireless signals.

[0034] 1B as a single element, 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 the air interface 116.

[0035] The transceiver 120 may be configured to modulate signals transmitted by the transmit / receive element 122 and demodulate signals received by the transmit / receive element 122. As noted above, the WTRU 102 may have multi-mode capabilities. Thus, the transceiver 120 may include multiple transceivers to enable the WTRU 102 to communicate via multiple RATs, such as, for example, NR and IEEE 802.11.

[0036] The processor 118 of the WTRU 102 may be coupled to and may receive user-entered data from a speaker / microphone 124, a keypad 126, and / or a display / touchpad 128 (e.g., a liquid crystal display (LCD) display unit or an 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. Additionally, the processor 118 may access information from and store data in any type of suitable memory, such as non-removable memory 130 and / or 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, etc. In other embodiments, 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 home computer (not shown).

[0037] The processor 118 may receive power from the power source 134 and may be configured to distribute and / or control the power to other components within the WTRU 102. The power source 134 may be any suitable device for providing power to the WTRU 102. For example, the power source 134 may include one or more dry batteries (e.g., nickel-cadmium (NiCd), nickel-zinc (NiZn), nickel metal hydride (NiMH), lithium-ion (Li-ion), etc.), solar cells, fuel cells, etc.

[0038] The processor 118 may also be coupled to a GPS chipset 136, which may be configured to provide location information (e.g., longitude and latitude) regarding the current location of the WTRU 102. In addition to, or instead of, information from the GPS chipset 136, the WTRU 102 may receive location information from base stations (e.g., base stations 114a, 114b) over the air interface 116 and / or determine its location based on the timing of signals 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.

[0039] 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. For example, the peripherals 138 may include an accelerometer, an electronic compass, a satellite transceiver, a digital camera (for photos and / or videos), 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, etc. The peripheral device 138 may include one or more sensors, which may be one or more of a gyroscope, an accelerometer, a Hall effect sensor, a magnetometer, a direction 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.

[0040] The WTRU 102 may include a full-duplex radio where transmission and reception of some or all of the signals associated with a particular subframe (e.g., for both the UL (e.g., for transmission) and downlink (e.g., for reception)) may be parallel and / or simultaneous. The full-duplex radio may include an interference management unit 139 for reducing and or substantially eliminating self-interference either through hardware (e.g., chokes) or signal processing via a processor (e.g., via a separate processor (not shown) or processor 118). In one embodiment, the WTRU 102 may include a half-duplex radio for transmission and reception of either some or all of the signals (e.g., associated with a particular subframe for either the UL (e.g., for transmission) or downlink (e.g., for reception)).

[0041] 1C is a system diagram illustrating the RAN 104 and the CN 106, according to one embodiment. As noted above, the RAN 104 may employ E-UTRA radio technology to communicate with the WTRUs 102a, 102b, 102c over the air interface 116. The RAN 104 may also communicate with the CN 106.

[0042] The RAN 104 may include eNodeBs 160a, 160b, and 160c, although it will be understood that the RAN 104 may include any number of eNodeBs while remaining consistent with an embodiment. The eNodeBs 160a, 160b, and 160c may each include one or more transceivers for communicating with the WTRUs 102a, 102b, and 102c over the air interface 116. In one embodiment, the eNodeBs 160a, 160b, and 160c may implement MIMO technology. Thus, the eNodeB 160a may, for example, use multiple antennas to transmit wireless signals to and / or receive wireless signals from the WTRU 102a.

[0043] Each of the eNodeBs 160a, 160b, and 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, etc. As shown in FIG. 1C, the eNodeBs 160a, 160b, 160c may communicate with one another via an X2 interface.

[0044] 1C may include a mobility management entity (MME) 162, a serving gateway (SGW) 164, and a packet data network (PDN) gateway (or PGW) 166. Although each of the foregoing elements is depicted as part of the CN 106, it will be understood that any of these elements may be owned and / or operated by an entity other than the CN operator.

[0045] The MME 162 may be connected to each of the eNodeBs 162a, 162b, 162c in the RAN 104 via an S1 interface and may function as a control node. For example, the MME 162 may be responsible for authenticating users of the WTRUs 102a, 102b, 102c, activating / deactivating bearers, selecting a particular serving gateway during initial attachment of the WTRUs 102a, 102b, 102c, etc. 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.

[0046] The SGW 164 may be connected to each of the eNodeBs 160a, 160b, and 160c in the RAN 104 via an S1 interface. The SGW 164 may generally route and forward user data packets to and from the WTRUs 102a, 102b, and 102c. The SGW 164 may perform other functions, such as anchoring the user plane during inter-eNodeB handovers, triggering paging when DL data is available to the WTRUs 102a, 102b, and 102c, and managing and storing the context of the WTRUs 102a, 102b, and 102c.

[0047] The SGW 164 may be connected to a PGW 166 that 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.

[0048] The CN 106 may facilitate communications with other networks. For example, 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 landline communications devices. For example, the CN 106 may include or 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. Additionally, the CN 106 may provide the WTRUs 102a, 102b, 102c with access to other networks 112, which may include other wired and / or wireless networks owned and / or operated by other service providers.

[0049] Although the WTRU is illustrated in FIGS. 1A-1D as a wireless terminal, it may be contemplated that in certain representative embodiments, such a terminal may use a wired communication interface with the communication network (e.g., temporarily or permanently).

[0050] In a representative embodiment, the other network 112 may be a WLAN.

[0051] A WLAN in infrastructure Basic Service Set (BSS) mode may have an access point (AP) of the BSS and one or more stations (STAs) associated with the AP. The AP may have access to or interface with a distribution system (DS) or another type of wired / wireless network that carries traffic into and / or out of the BSS. Traffic originating from outside the BSS to a STA may arrive through the AP and be delivered to the STA. Traffic originating from a STA to a destination outside the BSS may be sent to the AP for delivery to the respective destination. Traffic between STAs within the BSS may be sent, for example, through the AP, where the source STA may send traffic to the AP, and the AP may deliver the traffic to the destination STA. Traffic between STAs within the BSS may be considered and / or referred to as peer-to-peer traffic. Peer-to-peer traffic may be sent between (e.g., directly between) a source STA and a destination STA using a direct link setup (DLS). In certain representative embodiments, the DLS may use 802.11e DLS or 802.11z tunneled DLS (TDLS). A WLAN using an Independent BSS (IBSS) mode may not have an AP, and STAs within or using the IBSS (e.g., all of the STAs) may communicate directly with each other. The IBSS communication mode is sometimes referred to herein as an "ad hoc" communication mode.

[0052] When using the 802.11ac infrastructure mode of operation or a similar mode of operation, an AP may transmit beacons on a fixed channel, such as a primary channel. The primary channel may be a fixed width (e.g., a 20 MHz wide bandwidth) or a width that is dynamically set via signaling. The primary channel may be the operating channel of the BSS, but may be used by STAs to establish a connection with the AP. In certain representative embodiments, carrier sense multiple access with collision avoidance (CSMA / CA) may be implemented, for example, in an 802.11 system. With CSMA / CA, STAs (e.g., all STAs), 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 in a given BSS at any given time.

[0053] High Throughput (HT) STAs may use 40 MHz wide channels for communication, which may be formed, for example, through a combination of a primary 20 MHz channel and adjacent or non-adjacent 20 MHz channels.

[0054] A Very High Throughput (VHT) STA may support 20 MHz, 40 MHz, 80 MHz, and / or 160 MHz wide channels. A 40 MHz and / or 80 MHz channel may be formed by combining contiguous 20 MHz channels. A 160 MHz channel may be formed by combining eight contiguous 20 MHz channels or by combining two non-contiguous 80 MHz channels, which may be referred to as an 80+80 configuration. For the 80+80 configuration, after channel encoding, the data may pass through a segment parser, which may separate the data into two streams. Inverse Fast Fourier Transform (IFFT) processing and time-domain processing may be performed separately on each stream. The streams may be mapped to two 80 MHz channels, and the data may be transmitted by the transmitting STA. At the receiver of the receiving STA, the operations described above for the 80+80 configuration may be reversed, and the combined data may be transmitted to the Medium Access Control (MAC).

[0055] Sub-1 GHz operating modes are supported by 802.11af and 802.11ah. Channel operating bandwidths and carriers are reduced in 802.11af and 802.11ah compared to those used in 802.11n and 802.11ac. 802.11af supports 5 MHz, 10 MHz, and 20 MHz bandwidths in the TV White Space (TVWS) spectrum, while 802.11ah supports 1 MHz, 2 MHz, 4 MHz, 8 MHz, and 16 MHz bandwidths using non-TVWS spectrum. According to representative embodiments, 802.11ah may support meter-type control / machine-type communications, such as MTC devices, within a macro coverage area. MTC devices may have limited capabilities, including, for example, support for (e.g., only support for) certain specific and / or limited bandwidths. MTC devices may include batteries with above-threshold battery life (e.g., to maintain very long battery life).

[0056] WLAN systems that can support multiple channels and channel bandwidths, such as 802.11n, 802.11ac, 802.11af, and 802.11ah, include a channel that can be designated as a primary channel. The primary channel can have a bandwidth equal to the maximum common operating bandwidth supported by all STAs in the BSS. The bandwidth of the primary channel can be configured and / or limited by the STAs among all STAs operating in the BSS that support the minimum bandwidth operating mode. In an 802.11ah embodiment, the primary channel can be 1 MHz wide for STAs (e.g., MTC-type devices) that support (e.g., only) the 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) configuration can depend on the status of the primary channel. For example, if the primary channel is busy due to a STA (that only supports 1 MHz mode of operation) transmitting to the AP, the entire available frequency band may be considered busy even though most of the frequency band may remain inactive and available.

[0057] In the United States, the available frequency band that can be used by 802.11ah is 902MHz to 928MHz. In South Korea, the available frequency band is 917.5MHz to 923.5MHz. In Japan, the available frequency band is 916.5MHz to 927.5MHz. The total bandwidth available for 802.11ah is 6MHz to 26MHz depending on the country code.

[0058] 1D is a system diagram illustrating the RAN 113 and the CN 115, according to one embodiment. As mentioned above, the RAN 113 may employ NR radio technology to communicate with the WTRUs 102a, 102b, 102c over the air interface 116. The RAN 113 may also communicate with the CN 115.

[0059] The RAN 113 may include gNBs 180a, 180b, and 180c, although it will be understood that the RAN 113 may include any number of gNBs while remaining consistent with an embodiment. The gNBs 180a, 180b, and 180c may each include one or more transceivers for communicating with the WTRUs 102a, 102b, and 102c over the air interface 116. In an embodiment, the gNBs 180a, 180b, and 180c may implement MIMO technology. For example, the gNB 180a, 180b may transmit signals to and / or receive signals from the gNBs 180a, 180b, and 180c using beamforming. Thus, the gNB 180a may transmit and / or receive wireless signals to and / or from the WTRU 102a using, for example, multiple antennas. In one embodiment, the gNBs 180a, 180b, and 180c may implement carrier aggregation technology. For example, 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. In one embodiment, the gNBs 180a, 180b, and 180c may implement Coordinated Multi-Point (CoMP) technology. For example, the WTRU 102a may receive coordinated transmissions from the gNBs 180a and 180b (and / or 180c).

[0060] The WTRUs 102a, 102b, 102c may communicate with the gNBs 180a, 180b, and 180c using transmissions associated with a scalable numerology. For example, the OFDM symbol spacing and / or OFDM subcarrier spacing may vary for different transmissions, different cells, and / or different portions of the wireless transmission spectrum. The WTRUs 102a, 102b, 102c may communicate with the gNBs 180a, 180b, and 180c using subframes or transmission time intervals (TTIs) of different or scalable lengths (e.g., including different numbers of OFDM symbols and / or lasting different lengths of absolute time).

[0061] The gNBs 180a, 180b, and 180c may be configured to communicate with the WTRUs 102a, 102b, and 102c in a standalone configuration and / or a non-standalone configuration. In a standalone configuration, the WTRUs 102a, 102b, and 102c may communicate with the gNBs 180a, 180b, and 180c without accessing another RAN (e.g., eNodeBs 160a, 160b, 160c, etc.). In a standalone configuration, the WTRUs 102a, 102b, and 102c may utilize one or more of the gNBs 180a, 180b, and 180c as mobility anchor points. In a standalone configuration, the WTRUs 102a, 102b, and 102c may communicate with the gNBs 180a, 180b, and 180c using signals in unlicensed bands. In a non-standalone configuration, the WTRUs 102a, 102b, 102c may communicate with and connect to gNBs 180a, 180b, and 180c while also communicating with and connecting to another RAN, such as eNodeBs 160a, 160b, and 160c. For example, the WTRUs 102a, 102b, 102c may implement DC principles to communicate with one or more gNBs 180a, 180b, 180c and one or more eNodeBs 160a, 160b, 160c substantially simultaneously. In a non-standalone configuration, the eNodeBs 160a, 160b, 160c may act as mobility anchors for the WTRUs 102a, 102b, 102c, and the gNBs 180a, 180b, and 180c may provide additional coverage and / or throughput for serving the WTRUs 102a, 102b, 102c.

[0062] Each of the gNBs 180a, 180b, and 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 for network slicing, dual connectivity, interworking between NR and E-UTRA, routing of user plane data to User Plane Functions (UPFs) 184a, 184b, routing of control plane information to Access and Mobility Management Functions (AMFs) 182a, 182b, etc. As shown in FIG. 1D , the gNBs 180a, 180b, and 180c may communicate with each other via an Xn interface.

[0063] 1D 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 is depicted as part of the CN 115, it will be understood that any of these elements may be owned and / or operated by an entity other than the CN operator.

[0064] The AMF 182a, 182b may be connected to one or more of the gNBs 180a, 180b, 180c in the RAN 113 via an N2 interface and may function as a control node. For example, the AMF 182a, 182b may be responsible for authenticating users of the WTRUs 102a, 102b, 102c, supporting network slicing (e.g., handling different PDU sessions with different requirements), selecting a particular SMF 183a, 183b, managing registration areas, terminating NAS signaling, mobility management, etc. Network slicing may be used by the AMF 182a, 182b to customize the CN support of the WTRUs 102a, 102b, 102c based on the type of service utilizing the WTRUs 102a, 102b, 102c. For example, different network slices may be established for different use cases, such as services relying on ultra-reliable low latency (URLLC) access, services relying on enhanced massive mobile broadband (eMBB) access, services for machine type communication (MTC) access, etc. The AMF 162 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.

[0065] The SMFs 183a, 183b may be connected to the AMFs 182a, 182b in the CN 115 via an N11 interface. The SMFs 183a, 183b may also be connected to the UPFs 184a, 184b in the CN 115 via an N4 interface. The SMFs 183a, 183b may select and control the UPFs 184a, 184b and configure the routing of traffic through the UPFs 184a, 184b. The SMFs 183a, 183b may perform other functions, such as managing and allocating WTRU IP addresses, managing PDU sessions, controlling policy enforcement and QoS, providing downlink data notification, etc. The PDU session type may be IP-based, non-IP-based, Ethernet-based, etc.

[0066] The UPFs 184a, 184b may be connected to one or more of the gNBs 180a, 180b, 180c in the RAN 113 via an N3 interface, 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. The UPFs 184, 184b may perform other functions such as routing and forwarding packets, enforcing user plane policy, supporting multi-homed PDU sessions, handling user plane QoS, buffering downlink packets, providing mobility anchoring, etc.

[0067] The CN 115 may facilitate communication with other networks. For example, the CN 115 may include or communicate with an IP gateway (e.g., an IP multimedia subsystem (IMS) server) that acts as an interface between the CN 115 and the PSTN 108. In addition, the CN 115 may provide the WTRUs 102a, 102b, 102c with access to other networks 112, which may include other wired and / or wireless networks owned and / or operated by other service providers. In one embodiment, the WTRUs 102a, 102b, 102c may be connected to local data networks (DNs) 185a, 185b through the UPFs 184a, 184b via an N3 interface to the UPFs 184a, 184b and an N6 interface between the UPFs 184a, 184b and the DNs 185a, 185b.

[0068] 1A-1D and the corresponding descriptions thereof, one or more or all of the functions described herein with respect to one or more of the WTRUs 102a-d, base stations 114a-b, eNode-Bs 160a-c, MME 162, SGW 164, PGW 166, gNBs 180a-c, AMFs 182a-ab, UPFs 184a-b, SMFs 183a-b, DNs 185a-b, and / or any other devices 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. For example, the emulation devices may be used to test other devices and / or simulate network and / or WTRU functions.

[0069] The emulation devices may be designed to implement one or more tests of other devices in a lab environment and / or a carrier network environment. For example, one or more emulation devices may perform one or more or all functions while fully or partially implemented and / or deployed as part of a wired and / or wireless communication network to test other devices in the communication network. One or more emulation devices may perform one or more or all functions while temporarily implemented / deployed as part of a wired and / or wireless communication network. The emulation devices may be directly coupled to another device for testing purposes and / or may perform testing using wireless communication over the air.

[0070] One or more emulation devices may perform one or more functions, inclusive, while not being implemented / deployed as part of a wired and / or wireless communication network. For example, the emulation devices may be utilized in test scenarios in a test lab and / or in an undeployed (e.g., test) wired and / or wireless communication network to implement testing of one or more components. One or more emulation devices may be test equipment. Direct RF coupling and / or wireless communication via RF circuitry (which may include, e.g., one or more antennas) may be used by the emulation devices to transmit and / or receive data.

[0071] The WTRU may transmit or receive a physical channel or reference signal according to at least one spatial domain filter. The term "beam" may refer to a spatial domain filter. The WTRU may transmit a physical channel or signal using the same spatial domain filter as that used to receive an RS (e.g., CSI-RS) or SS block.

[0072] The WTRU may receive the first downlink channel or signal according to the same spatial domain filter or spatial reception parameters as the second downlink channel or signal. For example, such an association may exist between a physical channel, such as a PDCCH or PDSCH, and its respective DM-RS. When at least the first and second signals are reference signals, such an association may exist when the WTRU is configured with a quasi-colocation (QCL) assumption between the corresponding antenna ports. Such an association may be configured as a transmission configuration indicator (TCI) state. The WTRU may indicate the association between the CSI-RS or SS block and the DM-RS by an index into a set of TCI states configured by RRC and / or signaled by MAC CE. Such an index may also be referred to as a "beam index."

[0073] An aggregate TCI (e.g., common TCI, common beam, common RS, etc.) may refer to a beam / RS used (simultaneously) for multiple physical channels / signals. The term "TCI" may comprise at least a TCI state including at least one source RS to provide a basis (e.g., UE assumption) for determining a QCL and / or spatial filter. An aggregate TCI state instance may be equivalent to or identified with a Coreset pool identification (e.g., CORESETPoolIndex, TRP index, etc.).

[0074] A TRP (e.g., a transmitting and receiving point) may be used interchangeably with one or more of a TP (transmission point), an RP (receiving point), an RRH (radio remote head), a DA (distributed antenna), a BS (base station), a sector (a sector of a BS), and a cell (e.g., a geographical cell area served by a BS). A WTRU may be configured (or may receive a configuration) with one or more TRPs (i.e., multi-TRP, mTRP) that the WTRU may transmit and / or receive. A WTRU may be configured with one or more TRPs for one or more cells. A cell may be a serving cell or a secondary cell.

[0075] The WTRU may be configured with at least one RS for channel measurement purposes. This RS may be denoted as a Channel Measurement Resource (CMR) and may comprise a CSI-RS, an SSB, or another downlink RS transmitted from the TRP to the WTRU. The CMR may be configured with or associated with a TCI state.

[0076] Multi-panel studies for multiple transmission and reception points (mTRPs) have focused on panels and two TRPs. As an example, an mTRP (two TRPs) for the uplink (UL) may be defined to improve reliability in a time division multiplexing (TDM)-based repetition scheme. In such a configuration, the WTRU may use the same codeword (CW) for each physical uplink shared channel (PUSCH) on both TRP links.

[0077] The WRTU may support multiple codewords for the link between the panel and the TRP. For such a configuration, the WRTU may support one CW per panel and one CW for all panels. As an example, the WRTU may support one or more selected CWs between the base station (BS) and the WTRU. In scenarios where multiple codewords support association of multiple panels with the mTRP, a bitwidth reduction method may be implemented to reduce the overhead of channel quality indicator (CQI) and modulation and coding scheme (MCS) information exchange between the BS and the WTRU.

[0078] The data flow between the WTRU and the BS may follow different priorities in multiple codeword configurations. In scenarios where the priorities are known to the BS and the WTRU, a method may be implemented that enables the priority-aware transport block to perform codeword association for multi-panel to mTRP association. In multiple codeword configurations, there may be multiple transmission and reception points (mTRPs), multiple panels, modulation and coding scheme (MCS) indices, and channel state information (CSI) feedback.

[0079] 2 is a diagram 200 illustrating an example multiple transmission and reception point (mTRP) uplink (UL) scheme. As shown in FIG. 2, the mTRP method may enable data transmission to and / or from a WTRU using different TRPs of a gNB. The mTRP method may be used, for example, to increase throughput among cell-edge users, improve data rates, improve system capacity, and / or as a means to improve link diversity gain for scenarios such as URLLC and high-speed trains. The mTRP UL method may be limited to PUSCH repetitions to improve reliability.

[0080] As shown in 210, PUSCH repetitions may be sent for two TRPs scheduled by one PDCCH (e.g., a single DCI). As an example, two schemes may be supported for UL two TRPs. For example, the first scheme may be inter-slot repetition (e.g., repetition type A) as shown in 220. For example, the second scheme may be intra-slot repetition (e.g., repetition type B) as shown in 230.

[0081] The WTRU may transmit PUSCH repetitions to the mTRPs using different beams. To support two TRP UL beams from the WTRU, up to two SRS resource indicator (SRI) and / or two transmit precoder matrix indicator (TPMI) fields may be defined within a single downlink control information (DCI) field.

[0082] The WTRU may transmit TDM-based PUSCH repetitions. As an example, the BS may schedule UL transmissions over one PDCCH without being aware of the existence of any panel. Thus, the panels may be transparent to the BS, and it may be up to the WTRU to decide which panel to use. The WTRU may select a panel based on CQI calculations from both of the two TRPs. For example, each transmission instant panel may be activated by the WTRU for each TDM scheme. A mechanism for handling simultaneous multi-panel WTRU transmissions may not be defined.

[0083] The channel coding rate may determine the number of output bits and input bits for the channel decoding process. As the channel coding rate increases, the spectral efficiency may increase, but on the other hand, the protection against errors may decrease.

[0084] The modulation index may determine the number of bits per transmitted symbol used. As the modulation index increases, the spectral efficiency may increase, while the error protection decreases.

[0085] A modulation and coding scheme (MCS) index table may define modulation orders and channel coding rates that may jointly increase spectral efficiency. For example, as channel quality increases, higher MCS indices may be used.

[0086] Figure 3 is an example of an MCS index table for the PDSCH. As shown in Figure 3, the MCS index may consist of 5 bits and may be indicated for one or more or all codewords to the WTRU via the PDCCH. The codewords may be indicated for one or both of the DL and UL. The MCS index may be transmitted by the gNB to the WTRU in the DCI field of the PDCCH. The maximum number of MCS indices supported in the DCI may be 2, corresponding to two codewords for DL transmission. One CW may be defined for UL transmission, and the maximum number of layers may be 4.

[0087] 4 is an example of a 4-bit bit-width CQI table. CSI feedback from the WTRU may inform the gNB of parameters such as CQI, precoding matrix indicator (PMI), and / or rank indicator (RI). The CSI feedback may be sent on the PUCCH or PUSCH in UCI, and each field of the CSI may occupy a different bit-width.

[0088] As shown in Figure 4, the spectral efficiency may increase as the CQI index increases. As an example, the CQI value may range from 0 to 15, and the CQI value indicates the maximum MCS value that may be suitable for transmission to meet a certain block error rate.

[0089] The PMI may define one or more recommended indices from a codebook of precoding matrices.

[0090] The RI may define a recommended number of layers suitable for transmission.

[0091] A configuration that supports mTRP may increase the throughput and / or reliability of downlink and / or uplink transmissions.

[0092] In one embodiment, uplink mTRP may be applied to TDM-based repetition transmission. The TDM-based repetition scheme may increase reliability by exploiting channel diversity without increasing throughput. Furthermore, TDM-based transmission may limit the spectral efficiency of mTRP-based transmission.

[0093] For example, the number of codewords supported in DL and UL may be limited to 2 and 1, respectively. In an mTRP scenario, where links between the WTRU and TRP may exhibit significantly different channel qualities, using the same codeword may limit throughput. In this scenario, the same codeword may be used for different channels, and the resulting links may be assigned the same modulation and coding parameters. As a result, although the channel qualities may differ, the throughput of a high-quality link may be reduced due to the assignment of lower-order modulation and coding.

[0094] The number of supported codewords may be increased to match the number of TRPs to take advantage of spatial diversity. A WTRU that supports multiple panels may increase the impact of spatial diversity when different data may be transmitted from different panels.

[0095] As an example, when the same data is transmitted from multiple panels, the reliability of the transmission may be increased, as unrecoverable transport blocks on one link may be recovered on another link.

[0096] Schemes to support multiple panels may include repetitive transmission and TDM-based transmission, while keeping the panel information transparent to the BS.

[0097] Additionally, the increased throughput resulting from multiple panels may be limited by a limited number of codewords, which may prevent the exploitation of spatial diversity based on, for example, panel-TRP association. The number of supported codewords may be increased to match the number of panels, thereby realizing the benefits of panel spatial diversity over TRP association.

[0098] There may be a need or requirement to use a single codeword for all panel-TRP links. In this scenario, associating the same MCS index for all panel-TRP links may not be well-defined and / or straightforward. As a result, in this scenario, new methods, procedures, and / or signaling may be required to support linking multiple panels to mTRPs.

[0099] Maximizing throughput when allocating one or more panels to an mTRP may require defining multiple codewords for each link. However, the use of multiple codewords may result in significant signaling overhead, including MCS index and / or CSI feedback. This signaling overhead may require new, efficient methods to reduce this overhead.

[0100] The methods and procedures may be implemented to support multiple codewords for transmission, including multiple panels and / or mTRPs. For example, a different codeword may be used for each panel. For example, a single codeword may be used for all panels.

[0101] In one embodiment, the method for indicating the association of a panel between a WTRU and a TRP with a TRP may be performed by covering both downlink and uplink transmissions. Furthermore, the method may be implemented to reduce the overhead caused by additional CQI and / or MCS fields in the UCI and / or DCI.

[0102] In one embodiment, one or more panels may be presented and associated with one or more TRPs, and the method may be implemented to process the association of panels with TRPs and / or the indices of multiple panels and TPRs.

[0103] The association of panels with TRPs may also apply to FR2 and higher frequency bands where narrow beams may exist, and / or lower frequencies with Subscriber Data Management (SDM).

[0104] In a WTRU and mTRP configuration where the WTRU may be equipped with multiple panels, the association of panels with TRPs may not be straightforward: for example, each panel may receive CSI-RS from each TRP, and a panel may be associated with and / or mapped to multiple TRPs.

[0105] In one embodiment, there may be a different CW for each panel. For example, when one CW is supported per panel, each panel may be associated with one or more TRPs. For example, when one CW is supported per panel, each panel may be associated with at most one TRP.

[0106] The channel quality of the links between panels and TRPs may differ, for example, due to different orientations of the panels. In such cases, assigning each panel to the TRP with the best link quality and using resources for all links may lead to higher throughput. Associating each panel with one TRP may relax the synchronization requirements of the TRPs when panels receive and / or transmit different layers with different TRPs.

[0107] The association may depend on the number of available TRPs and panels. For example, the number of TRPs may define the number of potential TRPs with which the WTRU may establish a connection. The number of panels may indicate the number of (all) active TRPs.

[0108] Figure 5 is a diagram 500 illustrating an exemplary panel-TRP association, including four panels and three TRPs. Figure 6 is a diagram 600 illustrating an exemplary panel-TRP association, including four panels and five TRPs.

[0109] As shown in Figure 5, the number of TRPs (N TRP ) is the number of panels (N P ), size N TRP A subset of panels of size N may be used. As shown in Figure 6, if the number of TRPs is greater than the number of panels, P A subset of the TRPs may be used. The method for selecting the panel and / or subset of TRPs may be performed at the BS for the uplink. The method for selecting the panel and / or subset of TRPs may be performed at the WTRU for the downlink.

[0110] In one embodiment, the association between panels and TRPs may be formulated as a throughput maximization function. In the exemplary throughput maximization function shown below, x_(i, j) may be a binary decision variable indicating the link from panel i to TRP-j. TRPs may be distinguished using the coresetPoolIndex in the DCI. The x_(i, j) variable may be equal to 1 if the link from panel i to TRP-j is selected, and may be equal to 0 otherwise.

[0111] The throughput maximization function may ensure that the highest throughput can be selected by calculating the sum of the products of the CQI (CQI_(i,j)) and the rank (R_(i,j)) for the selected (i,j) link. For example, a constraint in the throughput maximization function may ensure that a panel and a TRP are connected to at most one link, and that the maximum number of links is equal to the minimum number of panels (N_P) and TRPs (N_TRP).

[0112]

number

[0113] In one embodiment, multiple codewords may be assigned per panel, and the multiple codewords per panel may use the same modulation and coding parameters because the channel characteristics between the panel TRPs may be the same.

[0114] FIG. 7 is a diagram 700 illustrating an example panel-TRP association for a single CW with four panels and three TRPs. In one embodiment, a single CW may be used for all panels. When the WTRU is required to use one CW for all panel-TRP links, as shown in FIG. 7, the same channel protection may be applied to all links, such that the same CQI may be reported for all links. For example, using only one codework may be important for low-complexity devices that conserve processing power. In such cases, an iterative optimization problem may be formulated to obtain the CQI that results in the highest throughput given an average block error rate (BLER). The formulated solution may be adapted to various numbers of panels and TRPs.

[0115] 8 is a diagram illustrating a procedure 800 for obtaining a single CQI value for a single CW for all panels. The method may be performed at the BS for the UL and at the WTRU for the DL. At 810, the WTRU (or BS) may select an initial CQI. For example, CQI * The variable is the link between all panels and TRP (max i、j CQI i、j ) can be set to the maximum CQI value defined for

[0116] At 820, the WTRU (or BS) can be configured to determine panel-TRP associations with CQIs. For example, a maximum objective function can be used to maximize the CQI for all panel-TRP links. *At 830, the WTRU (or BS) may determine (e.g., calculate) the average BLER of all panel-TRP links, e.g., as previously determined by a maximum objective function.

[0117] The WTRU (or BS) may determine whether the calculated average BLER is greater than a defined threshold at 840. If the WTRU (or BS) determines at 840 that the calculated average BLER is not greater than the threshold, the WTRU (or BS) may assign a CQI to all panel-to-TRP links at 850. * If the WTRU (or BS) determines at 840 that the calculated average BLER is greater than a threshold, the WTRU (or BS) may apply a CQI * The variables may be reduced by a specified amount. * The variable may be reduced by a value of 1. If the WTRU (or BS) determines in 840 that the calculated average BLER is greater than the threshold, the procedure may return to 820. For example, the maximum objective function may be a reduced CQI for all panel-TRP links. * It can be reimplemented iteratively using variables.

[0118] 9 is a diagram illustrating an example procedure 900 performed by a WTRU and one or more TRPs. The example procedure 900 may be applied to the downlink PDSCH. The WTRU may share capability information regarding its multi-panel and mTRP capabilities with the BS. The BS may then configure the WTRU to use these multi-panel and mTRP capabilities.

[0119] In the association of panels with TRPs for DL, the BS (e.g., TRP) may not need to recognize the panels. As shown in FIG. 9, TRP-1 may be a (e.g., master) BS from which a control channel may be transmitted. At 902, TRP-1 (e.g., BS) may transmit control information regarding CSI-RS from each TRP to the WTRU link. The WTRU may receive CSI-RS from each panel and calculate CSI (e.g., CQI and RI) for each TRP-to-panel link. The WTRU may then calculate panel-to-TRP association at 904. The WTRU may report the best CQI for each TRP in the UCI at 906. For example, this solution may require a CSI field (e.g., CQI and RI) for each TRP in the UCI.

[0120] In some examples, the WTRU may not report panel-level CSI. If the WTRU does not report panel-level CSI, the WTRU panel may be transparent to the BS (902). For example, the BS may receive CSI feedback from the WTRU and check the availability of resources in the TRP.

[0121] The BS may acknowledge the TRPs indicated by the WTRU, or the BS may indicate a subset of the TRPs to the WTRU, at 908. In either case, the BS may send the MCS index of each of the TRPs in the DCI to the WTRU, at 910.

[0122] In some examples, a coresetPoolIndex parameter may be utilized. For example, a new field in the DCI may be the number of TRPs, an MCS index for every TRP, and / or a corresponding TRP index (e.g., coresetPoolIndex). This configuration may be an example of explicit signaling associated with a DCI for a multi-panel mTRP.

[0123] The WTRU may receive the DCI including the MCS for each TRP information. In this configuration, once the WTRU receives the DCI including the MCS for each TRP information, the WTRU may update 912 the association between the panel and the TRP.

[0124] The indicated TRP may be the same as that indicated by the WTRU (eg, at 906). If the TRP indicated by the BS is the same as that indicated by the WTRU, no update may be necessary.

[0125] The TRP index indicated by the BS may be a subset of those indicated by the WTRU. If the TRP index indicated by the BS is a subset of those indicated by the WTRU, the WTRU may update the association of panels with TRPs to include those indicated by the BS. As an example, if the TRP index indicated by the BS is a subset of those indicated by the WTRU, the WTRU may update the association of panels with TRPs by including only those indicated by the BS. Following this update, the WTRU may receive 914 a PDSCH via the panel associated with the TRP.

[0126] 10 is a diagram illustrating an example procedure 1000 performed by a WTRU and one or more TRPs. The example procedure 1000 may be applied to an uplink PUSCH. Before determining and / or establishing any association, the WTRU may share capability information regarding multi-panel and mTRP capabilities with the BS. The BS may configure the WTRU to use these capabilities.

[0127] If a panel-TRP association for the UL is indicated, the BS (e.g., the TRP) may need to recognize the panel. As shown in FIG. 10, TRP-1 may be the BS from which the control channel may be transmitted (e.g., the master). At 1002, the WTRU may transmit an SRS to all TRPs from each panel. If TRP-1 is the BS from which the control channel is transmitted (e.g., the master), the WTRU may transmit an SRS to all TRPs from each panel. In response to the transmitted SRS, the BS may receive one or more reference signals from all panels to all TRPs. After receiving the reference signals from all panels to all TRPs, the BS may calculate the channel quality between all panels and the TRPs. Based on the calculated channel quality, the BS may calculate the panel-TRP association at 1004. The BS may then transmit an MCS for each TRP-panel association in the DCI at 1006. An additional MCS field for each TRP may be required, which may include, for example, the TRP and / or panel index for each MCS. This DCI configuration may be an example of explicit signaling associated with a DCI for a multi-panel mTRP. The WTRU may receive 1008 the DCI with MCS information and, in response, prepare for a PUSCH transmission.

[0128] In one embodiment, a CQI / MCS bitwidth reduction may be performed. A bitwidth reduction method may be performed to handle the increase in MCS information in multiple codeword scenarios.

[0129] In a single DCI mode of operation with multi-panel transmission in the DL, the CQI for each panel may be transmitted in the UCI transmitted from the WTRU to the BS. In a single DCI mode of operation with multi-panel transmission in the DL, the CQI for each WTRU panel may be transmitted in the UCI from the WTRU to the BS. For multi-panel transmission in the UL, the MCS for each panel may be transmitted in the DCI from the BS to the WTRU. As an example, for multi-panel transmission in the UL, the MCS for each panel may be transmitted in the DCI from the BS to the WTRU. The required CQI / MCS indicator bit width may increase linearly with the number of CWs. For example, transmitting the CQI / MCS for each codeword may require 4 / 5 bits per codeword in the UCI / DCI.

[0130] 11 is a flowchart illustrating an example procedure 1100 for bitwidth reduction based on calculated CQI / MCS values. Procedure 1100 may be implemented to determine the CQI of a single CW for all panels. Procedure 1100 may be implemented in the WTRU and / or the BS. Whether example process 1100 is implemented in the WTRU or the BS may depend on whether the process occurs during DL or UL transmission.

[0131] As shown in FIG. 11 , during DL transmission, the WTRU may receive a CSI-RS from each TRP to each panel at 1102. Once the CSI-RS signal is received, the WTRU may calculate an association between the panel and the TRP at 1104. For example, the WTRU may calculate a CQI for the link between each panel and the TRP. The WTRU may first receive a CSI-RS from each TRP to each panel during DL transmission. Then, the WTRU may calculate the association between the panel and the TRP. The WTRU may also calculate a CQI for the link between each panel and the TRP. Furthermore, among the calculated CQIs, a CQI value may be determined to calculate a differential CQI.

[0132] The WTRU may calculate a median CQI at 1106. The WTRU may calculate a differential CQI value for each CQI relative to the median CQI at 1108. The bit width of the differential CQI values may be less than or equal to the bit width of the actual CQI values. Furthermore, in some examples, the bit width of the differential CQI values may always be less than or equal to the bit width of the actual CQI values. The WTRU may calculate the total bit width of the median CQI and all differential CQIs.

[0133] At 1110, the WTRU may determine whether the total bit width is greater than a predetermined threshold. If the WTRU determines at 1110 that the total bit width is above the predetermined threshold, the WTRU may reduce the number of codewords at 1112 and the WTRU may return to 1104. For example, if the WTRU determines at 1110 that the total bit width is above the predetermined threshold, the WTRU may reduce the number of codewords at 1112 and iteratively recalculate the association between panels and TRPs using the reduced number of codewords. If the WTRU determines at 1110 that the bit width is less than the threshold, the WTRU may transmit the median CQI and accompanying differential CQI along with the TRP and / or panel index at 1114.

[0134] For CQI transmission, the associated UCI field may first include the median CQI and the corresponding TRP index, followed by the subsequent TRP-to-panel link and the differential CQI for the TRP index.

[0135] For MCS transmission, the relevant DCI fields may first include the median MCS, the corresponding TRP, and the panel index, followed by the subsequent TRP-to-panel link, the TRP, and the differential MCS for the panel index.

[0136] In one embodiment, an association of priority-aware CS / panels with TRPs may be performed. Different data streams (e.g., logical channels) may relate to different use cases and priorities. Each of the different data streams may apply different coding rates and / or modulations, which may themselves depend on the type / priority of the stream. As an example, the priority may be related to the QoS of the data and / or traffic class.

[0137] The application may be executed on the WTRU side, and the DL / UL priority may depend on the application / stream that the WTRU may request. The panel and TRP association method may be priority-based. If data stream priorities are available for use at the BS and / or WTRU PHY and / or MAC layers, the panel and TRP association method may be priority-based. For example, the availability of priority information at the MAC / PHY layer may be achieved by a cross-layer block that may transfer information between different protocol stack layers.

[0138] Figure 12 illustrates an example procedure 1200 performed by a WTRU and one or more TRPs to associate panels with TRPs for DL channels based on priority. The procedure disclosed in Figure 12 may be similar to that disclosed in Figure 9 for the association of DL panels with TRPs with the addition of modifications performed on the PDSCH data before transmission. In procedure 1200, an additional procedure may be performed to associate transport blocks (or logical channels) with codewords before initiating the PDSCH. This association may be based on priority for the transport blocks (or logical channels).

[0139] TRP-1 may be a (e.g., master) BS to which a control channel may be transmitted. TRP-1 (e.g., BS) may transmit control information regarding CSI-RS from each TRP to the WTRU link at 1202. The WTRU may receive CSI-RS from each panel and calculate CSI (e.g., CQI and RI) for each TRP-to-panel link. The WTRU may then calculate panel-to-TRP associations at 1204. The WTRU may report the best CQI for each TRP in the UCI at 1206. For example, this solution may require a CSI field (e.g., CQI and RI) for each TRP in the UCI.

[0140] The BS may acknowledge the TRPs indicated by the WTRU, or the BS may indicate a subset of the TRPs to the WTRU, at 1208. In either case, the BS may send the MCS index of each of the TRPs in the DCI to the WTRU, at 1210.

[0141] Once the WTRU receives the DCI including the MCS per TRP information, the WTRU may update the association between the panel and the TRP at 1212. The TRP-1 may associate a transport block (or logical channel) with a codeword at 1214. This association may be based on a priority for the transport block (or logical channel). Following the association of the transport block with the codeword, the WTRU (1208) may receive a PDSCH transmission at 1216 via the panel associated with the TRP.

[0142] Figure 13 illustrates an example procedure 1300 performed by a WTRU and one or more TRPs to associate panels with TRPs for UL channels based on priority. The procedure disclosed in Figure 13 may be similar to that disclosed in Figure 10 for associating UL panels with TRPs with the addition of modifications performed on PUSCH data before transmission. In procedure 1300, an additional procedure may be performed to associate transport blocks (or logical channels) with codewords before initiating a PUSCH. This association may be based on priority for the transport blocks (or logical channels).

[0143] The WTRU may transmit an SRS to all TRPs from each panel at 1302. If TRP-1 is the BS from which the control channel is transmitted (e.g., the master), the WTRU may transmit an SRS to all TRPs from each panel. In response to the transmitted SRS, the BS may receive one or more reference signals from all panels to all TRPs. After receiving the reference signals from all panels to all TRPs, the BS may calculate channel qualities between all panels and the TRPs. Based on the calculated channel qualities, the BS may calculate panel-TRP associations at 1304. The BS may then transmit an MCS for each TRP-panel association in the DCI at 1306. An additional MCS field for each TRP may be required, which may include, for example, the TRP and / or panel index for each MCS. This DCI configuration may be an example of explicit signaling associated with a DCI for a multi-panel mTRP. The WTRU may receive the DCI with the MCS information. After receiving the DCI, the WTRU may associate a transport block (or logical channel) with a codeword, at 1308. This association may be based on a priority for the transport block (or logical channel). Following the association of the transport block with the codeword, the WTRU may prepare for PUSCH transmission accordingly, at 1310.

[0144] The association of transport blocks (TBs) (or logical channels) to both UL and DL codewords may be performed based on a ranking of the priorities in descending order. For example, the highest priority may be assigned to the channel with the best quality based on having the highest MCS. If the priorities are the same, no action may be performed on that block.

[0145] In one embodiment, different CWs, and possibly associated CSI / MCSs, may be associated with different QoS targets (eg, different target BLERs, latencies, etc.).

[0146] In one embodiment, the block for associating transport blocks (or logical channels) to codewords (e.g., based on priority) may be an additional new block between DL-SCH / UL-SCH and PDSCH / PUSCH before the start of PDSCH / PUSCH processing.

[0147] Figure 14 is a table illustrating an example of TB priority. Figure 15 is a table illustrating an example of CW MCS index. Figures 14 and 15 may disclose exemplary TB priority and CW MCS index.

[0148] 16 is a table illustrating an example of an association of TBs with CWs. Based on FIGS. 14 and 15, FIG. 16 may disclose an example association of TBs with CWs.

[0149] In one embodiment, the WTRU may perform panel-TRP association. The WTRU may receive a DL reference signal for channel quality measurement from each TRP to each panel. The WTRU may calculate panel-TRP association. If one CW is allowed per panel, the WTRU may calculate an optimization to solve the optimal panel-TRP association, taking into account the link quality of all panel-TRP links.

[0150] If only one CW is allowed for every panel, the WTRU may compute an iterative optimization to find the best CQI value for all CW-TRP links to satisfy the BLER constraint or any other related constraints. The WTRU may transmit a CQI for each requested TRP association with the BS. If CQI bitwidth reduction is used, the WTRU may use the CQI bitwidth reduction mechanism to transmit a CQI for each TRP in the UCI. The WTRU may receive a grant for its requested TRP and / or an indication of a new MCS for the TRP association. In one embodiment, the WTRU may update the panel-TRP association. If priority-aware CW-TRP association is used, the BS may perform TB-CW association before the WTRU receives the PDSCH. The WTRU may then start receiving the PDSCH.

[0151] In one embodiment, the BS may perform panel-TRP association. The WTRU may transmit a UL reference signal for channel quality measurement from each panel to each TRP to the BS. The BS may calculate the panel-TRP association. If only one CW is allowed per panel, the BS may calculate an optimization to solve the optimal panel-TRP association, taking into account the link quality of all panel-TRP links.

[0152] If only one CW is allowed for every panel, the WTRU may calculate an iterative optimization to find the best CQI value of the link between all CWs and TRPs to satisfy the BLER constraint. The WTRU may receive an MCS index for each TRP (e.g., along with the panel index). If MCS bitwidth reduction is used, the BS may use the MCS bitwidth reduction mechanism to transmit an MCS for each TRP in the DCI. If priority-aware CW-TRP association is used, the WTRU may perform association of the TB with the CW before the WTRU transmits the PUSCH. The WTRU may then start transmitting the PUSCH.

[0153] The present disclosure provides methods and procedures for a multi-panel WTRU with mTRP access capability to receive retransmissions of TBs (e.g., codewords) with different priorities through panels and / or TRPs different from those originally scheduled. The WTRU may determine the best panel-TRP link according to CSI-RS measurements. The WTRU may then report the CSI of the top K TRPs for each panel to the NW. In the event of a decoder failure in one of the TBs received on a panel, the WTRU may apply a configured procedure to handle the retransmission.

[0154] A WTRU capable of associating multiple panels with an mTRP may have one or more features. The WTRU may be configured with rules for determining which panel to use for retransmission in the event of a decoding failure. The WTRU may be configured to use the next best panel-TRP link to receive packet retransmissions. The WTRU may stop processing through the panel that failed to decode and continue to receive DL data from all other panels. This first configuration may provide retransmissions without DCI.

[0155] The WTRU may be configured to receive retransmissions from another TRP to the corresponding panel when a decoding failure occurs. The association of the new TRP may be determined according to the previous CSI report. For example, a new DCI may be defined to allocate new resources to the panel from the new TRP (e.g., the next best TRP reported by the panel). This configuration of rules may require retransmission of the DCI.

[0156] The WTRU may be configured to omit ACK / NACK messages for low priority codewords.

[0157] The WTRU may be configured with a number of CSI reports per panel K. The WTRU may report the top K TRPs for CSI support for L1-RSRP.

[0158] The WTRU may receive and process the CSI-RS and may calculate CSI feedback for each panel. In calculating CSI feedback for each panel, the WTRU may receive CSI-RS from each TRP to each panel and may calculate CQI / PMI for the channel measurements from each TRP to the panel. The WTRU may then determine K TRPs for each panel that provide the top K CQI values. The WTRU may then generate K CSI feedback for each panel (e.g., per panel ID) including the TRP-ID, CQI, and PMI. The total number of CSI feedbacks is N p K, where N p indicates the number of panels. The WTRU will then p K CSI feedback messages may be fed back to the NW.

[0159] The WTRU may receive semi-persistent scheduling (SPS) on the TRP for the panel association. The WTRU may receive the SPS configuring the link between each TRP and the panel. The SPS may provide the WTRU with information on the TRP associated with each panel, the priority of the TRP for the panel association, the MCS for each TRP for the panel association, and the corresponding resources for each TRP for the panel association. The WTRU may receive scheduling information for each panel ID, including the TRP-ID, MCS, and resources.

[0160] The WTRU may receive a DCI to activate the CS. The WTRU may start receiving DL data on each panel simultaneously with different priorities.

[0161] The WTRU may detect a decoding failure on the TB. If a decoding failure is detected on the codeword with the highest priority, the WTRU may feed back a NACK to the NW and may determine which panel to use for retransmission.

[0162] The WTRU may determine which panel to use for retransmission based on the rule configuration. For example, as described above, the WRU may stop processing DL data from the panel receiving the highest priority TB. The WTRU may receive a retransmission of the packet from another panel with the next best CQI using the same resource allocation indicated by the SPS.

[0163] The WTRU may receive an indication in the DCI on the new TRP resources for the highest priority panel that has a decoding failure. After receiving the DCI, the WTRU may receive DL data on the panel from another TRP using the resources indicated in the DCI. The WTRU may already report CSI of the top K TRPs of the panel.

[0164] If a decoding failure is detected on a codeword with a lower priority, the WTRU may omit transmitting a NACK according to the configuration to prevent retransmissions on the low priority TB.

[0165] The WTRU may be triggered to update the TRP-panel associations. The NW may indicate to the WTRU to update the TRP-panel associations. The WTRU may then feed back a new CSI report for each panel and receive the new TRP-panel associations. After sending a NACK on the highest priority packet, the WTRU may receive the CSI-RS and update the TRP-panel associations. The WTRU may then feed back a new CSI report for each panel and receive the new TRP-panel associations.

[0166] 17 is a flowchart illustrating an example procedure 1700 for retransmission on different panels. A WTRU may perform procedure 1700, for example, in response to receiving a configuration rule from a network. At 1702, the WTRU may receive configuration information regarding dynamic retransmission of transport blocks on different panels. For example, the WTRU may receive configuration information indicating one or more rules for determining which panel from multiple panels to use for reception of a retransmitted codeword.

[0167] At 1704, the WTRU may measure a received DL reference signal (RS). For example, the WTRU may measure a DL RS transmitted from each of a plurality of TRPs, each DL RS being received from each of the plurality of TRPs via a panel of the plurality of panels.

[0168] The WTRU may select an association of TRPs with panels at 1706. For example, the WTRU may select a respective TRP for each of a plurality of panels based on the measured DL RS.

[0169] At 1708, the WTRU may transmit an association of the selected TRP with the panel. For example, the WTRU may transmit feedback indicating the selected respective TRP for each of the multiple panels. Channel quality (CQI) feedback may be provided for each combination of the multiple TRPs and multiple panels.

[0170] At 1710, the WTRU may receive DL data comprising different codewords having different priorities. For example, the WTRU may receive at least a first codeword from a first TRP of the plurality of TRPs via a first panel of the plurality of panels and a second codeword from a second TRP of the plurality of TRPs via a second panel of the plurality of panels.

[0171] At 1712, the WTRU may determine whether a retransmission is necessary. For example, the WTRU may determine that a retransmission of the first codeword from the first TRP should be received over the second TRP based on the first codeword being a higher priority than the second codeword. The determination may be based on one or more rules indicated by the configuration information.

[0172] If it is determined that a retransmission is necessary, the WTRU may receive the retransmission at 1714. For example, the WTRU may receive a retransmission of the first codeword from the first TRP via the second panel. Once the retransmission is received, the WTRU may repeatedly receive a downlink (DL) reference signal (RS) at 1704.

[0173] If it is determined that retransmission is not necessary, the WTRU may continue to receive DL data 1710 comprising different codewords with different priorities.

[0174] The processes described above may be implemented in a computer program, software, and / or firmware embodied in a computer-readable medium for execution by a computer and / or processor. Examples of computer-readable media include, but are not limited to, electronic signals (transmitted via wired and / or wireless connections) and / or computer-readable storage media. Examples of computer-readable storage media include, but are not limited to, read-only memory (ROM), random access memory (RAM), registers, cache memory, semiconductor memory devices, magnetic media such as, but not limited to, internal hard disks and removable disks, magneto-optical media, and / or optical media such as CD-ROM disks and / or digital versatile disks (DVDs). A processor in association with software may be used to implement a radio frequency transceiver for use in a WTRU, UE, terminal, base station, RNC, and / or any host computer.

Claims

1. 1. A method performed by a wireless transmit / receive unit (WTRU), the method comprising: receiving configuration information indicating one or more rules for determining which panel from among a plurality of panels should be used for receiving the retransmitted codeword; measuring a downlink (DL) reference signal (RS) transmitted from each of a plurality of transmit / receive points (TRPs), each DL RS being received from each of the plurality of TRPs via a panel of the plurality of panels; selecting a respective TRP for each of the plurality of panels based on the measured DL RS; transmitting feedback indicating the respective TRP selected for each of the plurality of panels, wherein channel quality indicator (CQI) feedback is provided for each combination of the plurality of TRPs and the plurality of panels; receiving at least a first codeword from a first TRP of the plurality of TRPs via a first panel of the plurality of panels and a second codeword from a second TRP of the plurality of TRPs via a second panel of the plurality of panels; determining, based on the first codeword being a higher priority than the second codeword and based on the one or more rules indicated by the configuration information, that a retransmission of the first codeword from the first TRP should be received via the second panel; receiving a retransmission of the first codeword from the first TRP via the second panel.

2. 2. The method of claim 1, further comprising receiving information indicating an association between each of the plurality of TRPs and each of the plurality of panels, a priority of the association between each TRP and a panel, a modulation and coding scheme (MCS) for the association between each TRP and a panel, or resources used for the association between each TRP and a panel.

3. The one or more rules: whether the WTRU is configured for retransmission without downlink control information (DCI) or retransmission with DCI; whether the WTRU should send an acknowledgement (ACK) message for the received codeword; or The method of claim 1 , further comprising indicating a number of configured CQI reports for each panel of a plurality of panels.

4. 2. The method of claim 1, wherein the feedback indicates that a CQI associated with a combination of the first TRP and the first panel is stronger than any other combination of the plurality of TRPs and the plurality of panels.

5. 2. The method of claim 1, further comprising: determining that a retransmission of the first codeword should be received from the first TRP via the second panel based on a CQI associated with a combination of the second TRP and the second panel that is stronger than any other combination of the plurality of TRPs and the plurality of panels except for the combination of the first TRP and the first panel.

6. 2. The method of claim 1, further comprising receiving an indication that the retransmission of the first codeword should be received from the first TRP via the second panel.

7. Detecting that a failure occurs when attempting to receive the first codeword from the first TRP via the first panel; 2. The method of claim 1, further comprising: transmitting a negative acknowledgement (NACK) in response to the failure before determining that the retransmission of the first codeword from the first TRP should be received via the second panel.

8. detecting that a failure has occurred when attempting to receive the first codeword from the first TRP via the first panel; transmitting updated CQI feedback for each combination of the plurality of TRPs and the plurality of panels; 10. The method of claim 1, further comprising: receiving information indicating an updated association between each of the plurality of TRPs and each of the plurality of panels.

9. The method of claim 1 , further comprising determining whether the CQI feedback provided to each TRP and associated panel meets a block error rate (BLER) threshold.

10. The method of claim 1 , further comprising applying bit width reduction to the CQI feedback provided to each TRP and associated panel.

11. 1. A wireless transmit / receive unit (WTRU), comprising: a processor, the processor comprising: receiving configuration information indicating one or more rules for determining which panel from among a plurality of panels should be used for receiving the retransmitted codeword; measuring a downlink (DL) reference signal (RS) transmitted from each of a plurality of transmit / receive points (TRPs), each DL RS being received from each of the plurality of TRPs via a panel of the plurality of panels; selecting a respective TRP for each of the plurality of panels based on the measured DL RS; transmitting feedback indicating the respective TRP selected for each of the plurality of panels, wherein channel quality indicator (CQI) feedback is provided for each combination of the plurality of TRPs and the plurality of panels; receiving at least a first codeword from a first TRP of the plurality of TRPs via a first panel of the plurality of panels, and receiving a second codeword from a second TRP of the plurality of TRPs via a second panel of the plurality of panels; determining, based on the first codeword being a higher priority than the second codeword and based on the one or more rules indicated by the configuration information, that a retransmission of the first codeword from the first TRP should be received via the second panel; a wireless transmit / receive unit (WTRU) configured to receive the retransmission of the first codeword from the first TRP via the second panel;

12. The processor:

12. The WTRU of claim 11, further configured to receive information indicating an association between each of the plurality of TRPs and each of the plurality of panels, a priority of the association between each TRP and a panel, a modulation and coding scheme (MCS) for the association between each TRP and a panel, or resources used for the association between each TRP and a panel.

13. The one or more rules: whether the WTRU is configured for retransmission without downlink control information (DCI) or retransmission with DCI; whether the WTRU should send an acknowledgement (ACK) message for the received codeword; or The WTRU of claim 11 , wherein the WTRU indicates a number of configured CQI reports for each panel of a plurality of panels.

14. 12. The WTRU of claim 11, wherein the feedback indicates that a CQI associated with a combination of the first TRP and the first panel is stronger than any other combination of the plurality of TRPs and the plurality of panels.

15. The processor: The WTRU of claim 11, further configured to determine that a retransmission of the first codeword should be received from the first TRP via the second panel based on a CQI associated with a combination of the second TRP and the second panel that is stronger than any other combination of the plurality of TRPs and the plurality of panels except for the combination of the first TRP and the first panel.

16. The processor: The WTRU of claim 11 , further configured to receive an indication that the retransmission of the first codeword should be received from the first TRP via the second panel.

17. The processor: Detecting that a failure occurs when attempting to receive the first codeword from the first TRP via the first panel; 12. The WTRU of claim 11, further configured to: transmit a negative acknowledgement (NACK) in response to the failure prior to the determination that the retransmission of the first codeword from the first TRP should be received via the second panel.

18. The processor: Detecting that a failure occurs when attempting to receive the first codeword from the first TRP via the first panel; transmitting updated CQI feedback for each combination of the plurality of TRPs and the plurality of panels; The WTRU of claim 11 , further configured to receive information indicating an updated association between each of the plurality of TRPs and each of the plurality of panels.

19. The processor: The WTRU of claim 11 , further configured to determine whether the CQI feedback provided to each TRP and associated panel meets a block error rate (BLER) threshold.

20. 1. A method performed by a base station (BS) in a radio access network (RAN), comprising: receiving a received uplink (UL) reference signal (RS) transmitted from each of a plurality of transmit / receive points (TRPs), each UL RS being received at each of the plurality of TRPs from each of a plurality of panels; determining a channel quality indicator (CQI) for each of the received UL RSs; selecting a respective panel from the plurality of panels for each of the plurality of TRPs based on the CQI determined for each of the received UL RSs; and transmitting a codeword and the selected respective panel for each of the plurality of TRPs, the codeword for each of the plurality of TRPs having a priority based on the CQI determined for each of the received UL RSs.

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