Method for acknowledgement mechanism based on unified TCI for MTRP

Abstract

Systems, methods, and devices are provided for unifying one or more acknowledgement mechanisms for transmitting a configuration indicator (TCI) and one or more transmit-receive points. In one example, a separate acknowledgement may be transmitted for each downlink control information (DCI) transmission of a plurality of downlink control information (DCI) transmissions with a unified TCI, and a separate single acknowledgement may be transmitted for one or more PDSCH transmissions associated with each DCI transmission of the plurality of DCI transmissions. In one or more acknowledgements of the acknowledgements, the HARQ-ACK codebook may include at least one HARQ-ACK bit based on receiving a PDSCH scheduled by the at least one DCI and at least one bit based on successful receiving of the at least one DCI indicating the unified TCI. Reporting the individual acknowledgement may be based on when one or more predetermined and / or configured conditions are satisfied.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of U.S. Provisional Application No. 63 / 335,022, filed on April 26, 2022, and U.S. Provisional Application No. 63 / 445,353, filed on February 14, 2023, the contents of which are incorporated herein by reference. Background Art

[0003] In some wireless systems, devices may transmit transmissions with specific configurations or parameters. The receiving device needs a way to understand those configurations and / or parameters and a way to confirm successful receipt of those transmissions. Summary of the invention

[0004] Systems, methods, and devices are provided for unifying one or more confirmation mechanisms for a transmission configuration indicator (TCI) and one or more transmission reception points. In one example, a separate confirmation may be transmitted for each of a plurality of downlink control information (DCI) transmissions with a unified TCI, and a separate single confirmation may be transmitted for one or more PDSCH transmissions associated with each of the plurality of DCI transmissions. In one or more of these confirmations, the HARQ-ACK codebook may include at least one HARQ-ACK bit based on receiving a PDSCH scheduled by at least one DCI and at least one bit based on successfully receiving at least one DCI indicating the unified TCI. Reporting the separate confirmation may be based on when one or more predetermined and / or configured conditions are met. BRIEF DESCRIPTION OF THE DRAWINGS

[0005] A more detailed understanding may be obtained from the following description given by way of example in conjunction with the accompanying drawings, in which like reference numerals indicate like elements, and in which:

[0006] Figure 1A is a system diagram illustrating an example communication system in which one or more disclosed embodiments may be implemented;

[0007] Figure 1B is an example of an embodiment in which Figure 1A A system diagram of an example wireless transmit / receive unit (WTRU) for use within the illustrated communication system;

[0008] Figure 1C is an example of an embodiment in which Figure 1A a system diagram of an example Radio Access Network (RAN) and an example Core Network (CN) used within the illustrated communication system;

[0009] Figure 1Dis an example of an embodiment in which Figure 1A A system diagram of another example RAN and another example CN used within the illustrated communication system;

[0010] Figure 2 An example of a separate ACK transmission for confirming the reception of a unified TCI is illustrated;

[0011] Figure 3 An example of a separate ACK transmission for confirming the reception of a unified TCI is illustrated;

[0012] Figure 4A An example of a separate ACK transmission for confirming the reception of a unified TCI is illustrated;

[0013] Figure 4B An example of a separate ACK transmission for confirming the reception of a unified TCI is illustrated;

[0014] Figure 5 An example of reliability enhancement for receiving DCI for unified TCI is illustrated; and

[0015] Figure 6 An example process of determining to transmit a DCI-ACK is illustrated. DETAILED DESCRIPTION

[0016] As discussed herein, "a" and "an" and similar phrases should be interpreted as "one or more" and "at least one." Similarly, any term ending with the suffix "(s)" may be interpreted as "one or more" and "at least one." For example, the term "may" may be interpreted as "may, for example."

[0017] Table 1 is a non-exhaustive example of some acronyms used herein.

[0018]

[0019]

[0020] Table 1 Figure 1A1 is a diagram illustrating an example communication system 100 in which one or more disclosed embodiments may be implemented. The communication system 100 may be a multiple access system that provides content such as voice, data, video, messaging, broadcast, etc. to multiple wireless users. The 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 discrete Fourier transform spread OFDM (ZT-UW-DFT-S-OFDM), unique word OFDM (UW-OFDM), resource block filtered OFDM, filter bank multi-carrier (FBMC), etc.

[0021] like Figure 1A As shown, the communication system 100 may include wireless transmit / receive units (WTRUs) 102a, 102b, 102c, 102d, a radio access network (RAN) 104, a core network (CN) 106, a public switched telephone network (PSTN) 108, the Internet 110 and other networks 112, but it should be understood that the disclosed embodiments contemplate any number of WTRUs, base stations, networks, and / or network elements. Each of the 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 (STA)) may be configured to send and / or receive wireless signals and may include user equipment (UE), a mobile station, a fixed or mobile subscriber unit, a subscription-based unit, a pager, a cellular phone, a personal digital assistant (PDA), a smart phone, 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 device, 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 an industrial and / or automated process chain environment), a consumer electronic device, a device operating on a commercial and / or industrial wireless network, etc. Any of the WTRUs 102a, 102b, 102c, and 102d may be interchangeably referred to as a UE.

[0022] The communication system 100 may also include a base station 114a and / or a base station 114b. Each of the base stations 114a, 114b may be any type of device configured to wirelessly interface with at least one of the WTRUs 102a, 102b, 102c, 102d to facilitate access to one or more communication networks, such as the CN 106, 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 evolved Node B (eNB), a Home Node B, a Home evolved Node B, a next generation Node B such as a gNode B (gNB), a new radio (NR) Node B, a site controller, an access point (AP), a wireless router, and the like. While the base stations 114a, 114b are each depicted as a single element, it will be appreciated that the base stations 114a, 114b may include any number of interconnected base stations and / or network elements.

[0023] The base station 114a may be part of the RAN 104, 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), a relay node, etc. The base station 114a and / or the base station 114b may be configured to send and / or receive wireless signals on one or more carrier frequencies, which may be referred to as a cell (not shown). These frequencies may be in a licensed spectrum, an unlicensed spectrum, or a combination of licensed and unlicensed spectrums. A cell may provide coverage of wireless services to a specific geographic area, which may be relatively fixed or may change over time. The cell may be further divided into cell sectors. For example, a cell associated with the base station 114a may be divided into three sectors. Therefore, in one embodiment, the base station 114a may include three transceivers, i.e., one transceiver for each sector of the cell. In an embodiment, the base station 114a may employ multiple-input multiple-output (MIMO) technology and may utilize multiple transceivers for each sector of the cell. For example, beamforming may be used to send and / or receive signals in a desired spatial direction.

[0024] 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).

[0025] More specifically, as noted above, the communication system 100 may be a multiple access system and may employ one or more channel access schemes, such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA, etc. For example, the base station 114a in the RAN 104 and the WTRUs 102a, 102b, 102c may implement a radio technology, such as Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access (UTRA), that may use Wideband CDMA (WCDMA) to establish the air interface 116. WCDMA may include communication protocols, such as High Speed ​​Packet Access (HSPA) and / or Evolved HSPA (HSPA+). HSPA may include High Speed ​​Downlink (DL) Packet Access (HSDPA) and / or High Speed ​​Uplink (UL) Packet Access (HSUPA).

[0026] In an 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) that may establish the air interface 116 using Long Term Evolution (LTE) and / or Advanced LTE (LTE-A) and / or Advanced LTE Pro (LTE-APro).

[0027] In an embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement a radio technology (such as NR radio access) that may establish the air interface 116 using NR.

[0028] In an 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 together implement LTE radio access and NR radio access, for example using the dual connectivity (DC) principle. Thus, the air interface utilized by the WTRUs 102a, 102b, 102c may be characterized by multiple types of radio access technologies and / or transmissions transmitted to / from multiple types of base stations (e.g., eNBs and gNBs).

[0029] In other embodiments, the base station 114a and the WTRUs 102a, 102b, 102c may implement radio technologies such as IEEE 802.11 (i.e., Wireless Fidelity (WiFi)), IEEE 802.16 (i.e., Worldwide Interoperability for Microwave Access (WiMAX)), CDMA2000, CDMA2000 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), etc.

[0030] Figure 1A The base station 114b in the 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 location, a home, a vehicle, a campus, an industrial facility, an air corridor (e.g., for use by drones), a road, and the like. 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 an 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 Figure 1A As shown, the base station 114 b may have a direct connection to the Internet 110. Therefore, the base station 114 b may not need to access the Internet 110 via the CN 106.

[0031] The RAN 104 may be in communication with the CN 106, which may be any type of network configured to provide voice, data, applications, and / or Voice over Internet Protocol (VoIP) services to one or more of the WTRUs 102a, 102b, 102c, 102d. The data may have different quality of service (QoS) requirements, such as different throughput requirements, latency requirements, error tolerance requirements, reliability requirements, data throughput requirements, mobility requirements, etc. The CN 106 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 described in detail in the accompanying drawings, the CN 106 may be configured to provide voice, data, applications, and / or Voice over Internet Protocol (VoIP) services to one or more of the WTRUs 102a, 102b, 102c, 102d. Figure 1AAlthough not shown in the figure, it will be appreciated that the RAN 104 and / or the CN 106 may be in direct or indirect communication with other RANs that employ the same RAT as the RAN 104 or a different RAT. For example, in addition to being connected to the RAN 104, which may utilize NR radio technology, the CN 106 may also be in communication with another RAN (not shown) that employs GSM, UMTS, CDMA 2000, WiMAX, E-UTRA, or WiFi radio technology.

[0032] The CN 106 may also act 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 that provides plain old telephone service (POTS). The Internet 110 may include a global system of interconnected computer networks and devices that use common communication protocols, such as the Transmission Control Protocol (TCP), the User Datagram Protocol (UDP), and / or the Internet Protocol (IP) in the TCP / IP Internet protocol suite. The networks 112 may include wired communication networks and / or wireless communication networks owned and / or operated by other service providers. For example, the networks 112 may include another CN connected to one or more RANs, which may employ the same RAT as the RAN 104 or a different RAT.

[0033] Some or all of the WTRUs 102a, 102b, 102c, 102d in the communication 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 via different wireless links). Figure 1A The illustrated WTRU 102c may be configured to communicate with the base station 114a, which may employ a cellular-based radio technology, and with the base station 114b, which may employ an IEEE 802 radio technology.

[0034] Figure 1B is a system diagram illustrating an example WTRU 102. Figure 1BAs shown, the WTRU 102 may include a processor 118, a transceiver 120, a transmit / receive element 122, a speaker / microphone 124, a keypad 126, a display / touchpad 128, a non-removable memory 130, a removable memory 132, a power supply 134, a global positioning system (GPS) chipset 136 and / or other peripherals 138, etc. It should be understood that the WTRU 102 may include any sub-combination of the foregoing elements while being consistent with an embodiment. As discussed herein, references to transmit or send may mean using one or more of the elements described herein to send a signal or send (e.g., the WTRU may use one or more transceivers or one or more transmitters to send a physical channel transmission; for example, this may inherently require the use of a processor operably connected to a transmitter that transmits a signal via one or more antennas). As discussed herein, transmit and send may be interchangeable.

[0035] The processor 118 may be a general purpose processor, a special purpose processor, a conventional processor, a digital signal processor (DSP), a plurality of microprocessors, one or more microprocessors associated with a DSP core, a controller, a microcontroller, an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), any other type of integrated circuit (IC), a state machine, etc. The processor 118 may perform signal decoding, 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. Although Figure 1B The processor 118 and the transceiver 120 are depicted as separate components, but it is understood that the processor 118 and the transceiver 120 may be integrated together in an electronic package or chip.

[0036] The send / receive element 122 may be configured to send a signal to a base station (e.g., base station 114a) or receive a signal from the base station via an air interface 116. For example, in one embodiment, the send / receive element 122 may be an antenna configured to send and / or receive an RF signal. In an embodiment, the send / receive element 122 may be a transmitter / detector configured to send and / or receive, for example, IR, UV or visible light signals. In another embodiment, the send / receive element 122 may be configured to send and / or receive both RF signals and optical signals. It should be understood that the send / receive element 122 may be configured to send and / or receive any combination of wireless signals.

[0037] Although the transmit / receive element 122 Figure 1B1 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.

[0038] The transceiver 120 may be configured to modulate signals to be transmitted by the transmit / receive element 122 and to demodulate signals received by the transmit / receive element 122. As noted above, the WTRU 102 may have multi-mode capabilities. For example, the transceiver 120 may include multiple transceivers for enabling the WTRU 102 to communicate via multiple RATs, such as NR and IEEE 802.11.

[0039] The processor 118 of the WTRU 102 may be coupled to 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) and may receive user input data therefrom. The processor 118 may also output user data to the speaker / microphone 124, the keypad 126, and / or the display / touchpad 128. In addition, the processor 118 may access information from and store data in any type of suitable memory, such as a non-removable memory 130 and / or a removable memory 132. The non-removable memory 130 may include a random access memory (RAM), a read-only memory (ROM), a hard disk, or any other type of memory storage device. The removable memory 132 may include a subscriber identity module (SIM) card, a memory stick, a secure digital (SD) memory card, and the like. In other embodiments, the processor 118 may access information from and store data in a memory that is not physically located on the WTRU 102, such as on a server or a home computer (not shown).

[0040] The processor 118 may receive power from the power source 134, and may be configured to distribute and / or control power to other components in the WTRU 102. The power source 134 may be any suitable device for powering the WTRU 102. For example, the power source 134 may include one or more dry cell batteries (e.g., nickel-cadmium (NiCd), nickel-zinc (NiZn), nickel-metal hydride (NiMH), lithium-ion (Li-ion), etc.), solar cells, fuel cells, etc.

[0041] The processor 118 may also be coupled to the GPS chipset 136, which may be configured to provide location information (e.g., longitude and latitude) regarding the current location of the WTRU 102. In addition to or in lieu of the information from the GPS chipset 136, the WTRU 102 may receive location information from a base station (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 any suitable location-determination method while remaining consistent with an embodiment.

[0042] The processor 118 may also be coupled to other peripherals 138, which may include one or more software modules 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 video), a universal serial bus (USB) port, a vibration device, a television transceiver, a hands-free headset, module, FM radio unit, digital music player, media player, video game player module, Internet browser, virtual reality and / or augmented reality (VR / AR) device, activity tracker, etc. The peripheral device 138 may include one or more sensors. The sensor may be one or more of the following: a gyroscope, an accelerometer, a Hall effect sensor, a magnetometer, an orientation sensor, a proximity sensor, a temperature sensor, a time sensor; a geolocation sensor, an altimeter, a light sensor, a touch sensor, a magnetometer, a barometer, a gesture sensor, a biometric sensor, a humidity sensor, etc.

[0043] The WTRU 102 may include a full-duplex radio for which transmission and reception of some or all of the signals (e.g., associated with specific subframes for both UL (e.g., for transmission) and DL (e.g., for reception)) may be concurrent and / or simultaneous. The full-duplex radio may include an interference management unit for reducing and or substantially eliminating self-interference via signal processing performed by hardware (e.g., a choke) or via a processor (e.g., a separate processor (not shown) or via the processor 118). In an embodiment, the WTRU 102 may include a half-duplex radio for which transmission and reception of some or all of the signals (e.g., associated with specific subframes for both UL (e.g., for transmission) or DL ​​(e.g., for reception)) may be concurrent and / or simultaneous.

[0044] Figure 1C1 is a system diagram illustrating the RAN 104 and the CN 106 in accordance with an embodiment. As noted above, the RAN 104 may employ an E-UTRA radio technology to communicate with the WTRUs 102a, 102b, 102c over the air interface 116. The RAN 104 may also be in communication with the CN 106.

[0045] The RAN 104 may include evolved Node-Bs 160a, 160b, 160c, though it will be appreciated that the RAN 104 may include any number of evolved Node-Bs while remaining consistent with an embodiment. The evolved Node-Bs 160a, 160b, 160c may each include one or more transceivers for communicating with the WTRUs 102a, 102b, 102c over the air interface 116. In one embodiment, the evolved Node-Bs 160a, 160b, 160c may implement MIMO technology. Thus, the evolved Node-B 160a, for example, may use multiple antennas to transmit wireless signals to and / or receive wireless signals from the WTRU 102a.

[0046] Each of the evolved Node Bs 160a, 160b, 160c may be associated with a particular cell (not shown) and may be configured to handle radio resource management decisions, handover decisions, scheduling of users in UL and / or DL, etc. Figure 1C As shown, the eNode-Bs 160a, 160b, 160c may communicate with one another via an X2 interface.

[0047] Figure 1C The illustrated CN 106 may include a mobility management entity (MME) 162, a serving gateway (SGW) 164, and a packet data network (PDN) gateway (PGW) 166. Although the foregoing elements are depicted as part of the CN 106, it should be understood that any of these elements may be owned and / or operated by an entity other than the CN operator.

[0048] The MME 162 may be connected to each of the evolved Node-Bs 162a, 162b, 162c in the RAN 104 via an S1 interface and may serve as a control node. For example, the MME 162 may be responsible for authenticating users of the WTRUs 102a, 102b, 102c, bearer activation / deactivation, selecting a particular serving gateway during an initial attach of the WTRUs 102a, 102b, 102c, 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.

[0049] The SGW 164 may be connected to each of the evolved Node-Bs 160a, 160b, 160c in the RAN 104 via an S1 interface. The SGW 164 may generally route and forward user data packets to / from the WTRUs 102a, 102b, 102c. The SGW 164 may perform other functions, such as anchoring the user plane during inter-evolved Node-B handovers, triggering paging when DL data is available for the WTRUs 102a, 102b, 102c, managing and storing the context of the WTRUs 102a, 102b, 102c, and the like.

[0050] The SGW 164 may be connected to the PGW 166, which may provide the WTRUs 102a, 102b, 102c with access to packet-switched networks, such as the Internet 110, to facilitate communications between the WTRUs 102a, 102b, 102c and IP-enabled devices.

[0051] 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 land-line communications devices. For example, the CN 106 may include or may be in communication with an IP gateway (e.g., an IP Multimedia Subsystem (IMS) server) that acts as an interface between the CN 106 and the PSTN 108. In addition, the CN 106 may provide the WTRUs 102a, 102b, 102c with access to other networks 112, which may include other wired networks and / or wireless networks owned and / or operated by other service providers.

[0052] Although the WTRU Figures 1A to 1D Although described as wireless terminals, it is contemplated that in certain representative embodiments, such terminals may (eg, temporarily or permanently) use a wired communication interface with a communication network.

[0053] In a representative embodiment, the other network 112 may be a WLAN.

[0054] A WLAN in infrastructure basic service set (BSS) mode may have an access point (AP) for a BSS and one or more stations (STA) associated with the AP. The AP may have access or an interface to a distribution system (DS) or another type of wired / wireless network that carries traffic to and / or carries traffic away from the BSS. Traffic originating from outside the BSS and leading to the STA may be reached by the AP and may be delivered to the STA. Traffic originating from the STA and leading to a destination outside the BSS may be transmitted to the AP to be delivered to the corresponding destination. Traffic between STAs within the BSS may be transmitted by the AP, for example, wherein the source STA may transmit traffic to the AP, and the AP may deliver traffic to the destination STA. Traffic between STAs within the BSS may be considered and / or referred to as point-to-point traffic. Point-to-point traffic may be transmitted between the source STA and the destination STA (e.g., directly between them) using a direct link establishment (DLS). In certain representative embodiments, the DLS may use 802.11e DLS or 802.11z tunnel DLS (TDLS). A WLAN using an independent BSS (IBSS) mode may not have an AP, and STAs within or using the IBSS (eg, all STAs in the STA) may communicate directly with each other. The IBSS communication mode may sometimes be referred to herein as an "ad hoc" communication mode.

[0055] When using the 802.11ac infrastructure operating mode or a similar operating mode, the AP may send 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 dynamically set width. The primary channel may be an operating channel of the BSS and may be used by the STA to establish a connection with the AP. In certain representative embodiments, carrier sense multiple access / collision avoidance (CSMA / CA) may be implemented, for example, in an 802.11 system. For CSMA / CA, a STA (e.g., each STA) (including the AP) may listen to the primary channel. If the primary channel is listened / detected and / or determined to be busy by a particular STA, the particular STA may back off. One STA (e.g., only one station) may transmit at any given time in a given BSS.

[0056] High throughput (HT) STAs may communicate using a 40 MHz wide channel, for example, via a combination of a primary 20 MHz channel and adjacent or non-adjacent 20 MHz channels to form a 40 MHz wide channel.

[0057] Very high throughput (VHT) STA can support 20MHz, 40MHz, 80MHz and / or 160MHz wide channels. 40MHz channels and / or 80MHz channels can be formed by combining continuous 20MHz channels. 160MHz channels can be formed by combining 8 continuous 20MHz channels, or by combining two non-continuous 80MHz channels (this can be called 80+80 configuration). For 80+80 configuration, after channel coding, the data can pass through a segment parser that can divide the data into two streams. Each stream can be processed by inverse fast Fourier transform (IFFT) and time domain processing separately. These streams can be mapped to two 80MHz channels, and data can be sent by the transmitter STA. At the receiver of the receiver STA, the above-mentioned operation for the 80+80 configuration can be reversed, and the combined data can be transmitted to the medium access control (MAC).

[0058] 802.11af and 802.11ah support operating modes below 1GHz. Channel operating bandwidths and carriers are reduced in 802.11af and 802.11ah relative to those used in 802.11n and 802.11ac. 802.11af supports 5MHz, 10MHz, and 20MHz bandwidths in the TV White Space (TVWS) spectrum, and 802.11ah supports 1MHz, 2MHz, 4MHz, 8MHz, and 16MHz bandwidths using non-TVWS spectrum. According to a representative embodiment, 802.11ah may support meter type control / machine type communication (MTC), such as MTC devices in macro coverage areas. MTC devices may have certain capabilities, such as limited capabilities, including support for (e.g., only support for) certain bandwidths and / or limited bandwidths. MTC devices may include batteries with battery life above a threshold (e.g., to maintain very long battery life).

[0059] WLAN systems that can support multiple channels and channel bandwidths (such as 802.11n, 802.11ac, 802.11af, and 802.11ah) include channels that can be designated as primary channels. The primary channel may have a bandwidth equal to the maximum common operating bandwidth supported by all STAs in the BSS. The bandwidth of the primary channel may be set and / or limited by a STA (which supports the minimum bandwidth operating mode) from all STAs operating in the BSS. In the example of 802.11ah, for STAs (e.g., MTC-type devices) that support (e.g., only support) a 1MHz mode, the primary channel may be 1MHz wide, even if the AP and other STAs in the BSS support 2MHz, 4MHz, 8MHz, 16MHz, and / or other channel bandwidth operating modes. Carrier sensing and / or network allocation vector (NAV) settings may depend on the state of the primary channel. If the primary channel is busy, for example, because a STA (which only supports a 1MHz operating mode) is transmitting to the AP, all available bands may be considered busy even if most of the available bands remain idle.

[0060] In the United States, the available frequency band for 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.

[0061] Figure 1D 1 is a system diagram illustrating the RAN 104 and the CN 106 in accordance with an embodiment. As noted above, the RAN 104 may employ NR radio technology to communicate with the WTRUs 102a, 102b, 102c over the air interface 116. The RAN 104 may also be in communication with the CN 106.

[0062] The RAN 104 may include gNBs 180a, 180b, 180c, though it will be appreciated that the RAN 104 may include any number of gNBs while remaining consistent with an embodiment. The gNBs 180a, 180b, 180c may each include one or more transceivers for communicating with the WTRUs 102a, 102b, 102c over the air interface 116. In one embodiment, the gNBs 180a, 180b, 180c may implement MIMO technology. For example, the gNBs 180a, 180b may utilize beamforming to send signals to and / or receive signals from the gNBs 180a, 180b, 180c. Thus, the gNB 180a may, for example, use multiple antennas to send wireless signals to and / or receive wireless signals from the WTRU 102a. In an embodiment, the gNBs 180a, 180b, 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 an unlicensed spectrum, while the remaining component carriers may be on a licensed spectrum. In an embodiment, the gNBs 180a, 180b, 180c may implement coordinated multi-point (CoMP) technology. For example, the WTRU 102a may receive coordinated transmissions from the gNB 180a and the gNB 180b (and / or the gNB 180c).

[0063] The WTRUs 102a, 102b, 102c may communicate with the gNBs 180a, 180b, 180c using transmissions associated with a set of parameters that may be scalable. For example, 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, 180c using subframes or transmit time intervals (TTIs) of varying or scalable lengths (e.g., containing varying numbers of OFDM symbols and / or varying absolute time lengths over time).

[0064] The gNBs 180a, 180b, 180c may be configured to communicate with the WTRUs 102a, 102b, 102c in a standalone configuration and / or a non-standalone configuration. In a standalone configuration, the WTRUs 102a, 102b, 102c may communicate with the gNBs 180a, 180b, 180c while not accessing other RANs (e.g., such as the eNodeBs 160a, 160b, 160c). In a standalone configuration, the WTRUs 102a, 102b, 102c may use one or more of the gNBs 180a, 180b, 180c as mobility anchors. In a standalone configuration, the WTRUs 102a, 102b, 102c may communicate with the gNBs 180a, 180b, 180c using signals in an unlicensed band. In a non-standalone configuration, the WTRU 102a, 102b, 102c may communicate / connect with the gNB 180a, 180b, 180c while also communicating / connecting with another RAN, such as the evolved Node-B 160a, 160b, 160c. For example, the WTRU 102a, 102b, 102c may implement the DC principle to communicate with one or more gNBs 180a, 180b, 180c and one or more evolved Node-Bs 160a, 160b, 160c substantially simultaneously. In a non-standalone configuration, the evolved Node-B 160a, 160b, 160c may act as a mobility anchor for the WTRU 102a, 102b, 102c, and the gNB 180a, 180b, 180c may provide additional coverage and / or throughput for serving the WTRU 102a, 102b, 102c.

[0065] Each of the gNBs 180a, 180b, 180c may be associated with a specific cell (not shown) and may be configured to handle radio resource management decisions, handover decisions, scheduling of users in UL and / or DL, support of network slicing, interworking between DC, NR and E-UTRA, routing of user plane data towards user plane functions (UPFs) 184a, 184b, routing of control plane information towards access and mobility management functions (AMFs) 182a, 182b, etc. Figure 1D As shown, gNBs 180a, 180b, and 180c may communicate with each other via an Xn interface.

[0066] Figure 1DThe illustrated CN 106 may include at least one AMF 182a, 182b, at least one UPF 184a, 184b, at least one session management function (SMF) 183a, 183b, and possible data networks (DNs) 185a, 185b. Although the aforementioned elements are depicted as part of the CN 106, it should be understood that any of these elements may be owned and / or operated by an entity other than the CN operator.

[0067] The AMF 182a, 182b may be connected to one or more of the gNBs 180a, 180b, 180c in the RAN 104 via the N2 interface and may act as a control node. For example, the AMF 182a, 182b may be responsible for authenticating users of the WTRU 102a, 102b, 102c, support of network slicing (e.g., handling of different protocol data unit (PDU) sessions with different requirements), selecting a specific SMF 183a, 183b, management of registration areas, termination of non-access stratum (NAS) signaling, mobility management, etc. The AMF 182a, 182b may use network slicing to customize CN support for the WTRU 102a, 102b, 102c based on the type of services utilized by the WTRU 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 MTC access, etc. The AMF 182a, 182b may provide a control plane function for switching between the RAN 104 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.

[0068] The SMF 183a, 183b may be connected to the AMF 182a, 182b in the CN 106 via the N11 interface. The SMF 183a, 183b may also be connected to the UPF 184a, 184b in the CN 106 via the N4 interface. The SMF 183a, 183b may select and control the UPF 184a, 184b, and configure the traffic routing through the UPF 184a, 184b. The SMF 183a, 183b may perform other functions, such as managing and allocating UE IP addresses, managing PDU sessions, controlling policy implementation and QoS, providing DL data notification, etc. The PDU session type may be IP-based, non-IP-based, Ethernet-based, etc.

[0069] The UPF 184a, 184b may be connected to one or more of the gNBs 180a, 180b, 180c in the RAN 104 via the 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 UPF 184, 184b may perform other functions, such as routing and forwarding packets, enforcing user plane policies, supporting multi-homed PDU sessions, handling user plane QoS, buffering DL packets, providing mobility anchoring, etc.

[0070] The CN 106 may facilitate communications with other networks. For example, the CN 106 may include or may communicate with an IP gateway (e.g., an IP Multimedia Subsystem (IMS) server) that acts as an interface between the CN 106 and the PSTN 108. In addition, the CN 106 may provide the WTRUs 102a, 102b, 102c with access to other networks 112, which may include other wired networks and / or wireless networks owned and / or operated by other service providers. In one embodiment, the WTRUs 102a, 102b, 102c may be connected to the DNs 185a, 185b via the UPFs 184a, 184b via the N3 interfaces to the UPFs 184a, 184b and the N6 interfaces between the UPFs 184a, 184b and the local DNs 185a, 185b.

[0071] Given that Figures 1A to 1D as well as Figures 1A to 1D Corresponding to the description of the present invention, one or more or all of the functions described herein with reference to one or more of the following items may be performed by one or more simulation devices (not shown): WTRU102a-d, base station 114a-b, evolved Node B 160a-c, MME 162, SGW 164, PGW 166, gNB 180a-c, AMF182a-b, UPF 184a-b, SMF 183a-b, DN 185a-b and / or any other device described herein. The simulation device may be one or more devices configured to emulate one or more or all of the functions described herein. For example, the simulation device can be used to test other devices and / or simulate network and / or WTRU functions.

[0072] The simulation device may be designed to implement one or more tests of other devices in a laboratory environment and / or in an operator network environment. For example, one or more simulation devices may perform one or more functions or all functions while being fully or partially implemented and / or deployed as part of a wired and / or wireless communication network in order to test other devices within the communication network. One or more simulation devices may perform one or more functions or all functions while being temporarily implemented / deployed as part of a wired and / or wireless communication network. The simulation device may be directly coupled to another device for the purpose of testing and / or performing tests using over-the-air wireless communications.

[0073] One or more simulation devices can perform one or more (including all) functions without being implemented / deployed as part of a wired and / or wireless communication network. For example, the simulation device can be used in a test scenario in a test laboratory and / or a non-deployed (e.g., testing) wired and / or wireless communication network to implement testing of one or more components. One or more simulation devices can be test equipment. Direct RF coupling and / or wireless communication via RF circuits (e.g., which may include one or more antennas) can be used by the simulation device to send and / or receive data.

[0074] The WTRU may transmit or receive a physical channel transmit or reference signal (RS) according to at least one spatial domain filter. As used herein, the term "beam" may be used to refer to a spatial domain filter, and the two terms may be interchangeable. As used herein, unless otherwise specified, RS may be used interchangeably with one or more of an RS resource, an RS resource set, an RS port, and / or an RS port group. As used herein, unless otherwise specified, RS may be used interchangeably with one or more of an SSB, a channel state information reference signal (CSI-RS), a sounding reference signal (SRS), and / or a demodulation reference signal (DM-RS).

[0075] In some cases, the WTRU may transmit a physical channel transmission or signal using the same spatial domain filters used to receive RS (e.g., CSI-RS) or synchronization signal blocks (SS blocks). The WTRU transmission may be referred to as the "target" and the received RS or SS block may be referred to as the "reference" or "source" (e.g., the two transmission types are different). In such cases, the WTRU may be said to transmit the target physical channel or signal based on the spatial relationship of the reference to such RS or SS block.

[0076] In some cases, the WTRU may transmit a first physical channel transmission or signal according to the same spatial domain filter as used to transmit a second physical channel transmission or signal. The first transmission and the second transmission may be referred to as "target" and "reference" (or "source"), respectively (e.g., in the case where the second transmission is transmitted earlier than the first transmission). In such cases, the WTRU may be said to transmit the first (target) physical channel transmission or signal according to a spatial relationship with reference to the second (reference) physical channel or signal.

[0077] The spatial relationship may be implicit, configured by RRC, or signaled by MAC CE or DCI. For example, the WTRU may implicitly transmit the DM-RS for PUSCH transmission and PUSCH according to the same spatial domain filter as the SRS, which is indicated by the SRS resource indicator (SRI) indicated in the DCI or configured by RRC. In another example, the spatial relationship may be configured by RRC for SRI or signaled by MAC CE for PUCCH. As noted herein, "beam (e.g., analog beam)" may be equivalent to "spatial domain (analog) filter / coefficient / information, etc." As used herein, a "beam indication" may be a unidirectional indication (e.g., from a gNB to a WTRU) between two signals (e.g., one is a source and the other is a target); a beam indication may be equivalent to, and may be interchangeable with, a "spatial relationship" or spatial association relationship between two signals, as used herein.

[0078] In some cases, the WTRU may receive a first (target) downlink channel transmission or signal according to the same spatial domain filter or spatial reception parameters as a second (reference) downlink channel or signal, thereby demonstrating an association between the target and the reference; it should be noted that the first transmission / signal may be later in time than the second transmission / signal. For example, such an association may exist between a physical channel such as a PDCCH or PDSCH and its corresponding DM-RS. Such an association may exist when the WTRU is configured with a quasi co-location (QCL) assumption type D between corresponding antenna ports, at least when the first signal and the second signal are reference signals. Such an association may be configured as a transmit configuration indicator (TCI) state. The WTRU may indicate the association between a CSI-RS or SS block and a DM-RS by an index to a TCI state set (configured by RRC and / or signaled by a MAC CE). Such an indication may also be referred to as a "beam indication"; and the TCI state may also be referred to as a spatial relationship. For example, the WTRU may receive a configuration message including a TCI state, which the WTRU may then use to determine the spatial domain filter for the target based on a reference (e.g., receive an RS and then determine the spatial domain filter for transmitting a physical channel transmission based on the configured TCI state).

[0079] In another example, each configured TCI state (e.g., a TCI state information element (IE) in RRC) may include a source RS (e.g., a CSI-RS resource ID or SSB index, etc.). Each TCI state (e.g., IE) may be configured under a physical (target) channel / signal. For example, a CORESET (e.g., for PDCCH) may be configured with a TCI state. This means that the WTRU can monitor the PDCCH via the CORESET using a spatial domain filter derived using the (source / reference) RS indicated in the TCI state. This example may represent a separate spatial relationship. In other examples, there may need to be instances of multiple spatial relationships where a single TCI state (source / reference) applies to multiple targets (e.g., a common TCI state or a unified TCI state).

[0080] A unified TCI (uTCI) (e.g., uTCI state, common TCI, common beam, common RS, etc.) may refer to a beam / RS to be used for multiple physical channels / signals (e.g., simultaneously). As used herein, the term "TCI" may include a TCI state (e.g., IE) that includes at least one source RS to provide a reference (e.g., WTRU assumption) for determining the QCL and / or spatial filter of a target channel / transmission / signal. As used herein, unless otherwise specified, unified TCI may be used interchangeably with one or more of unified TCI state, TCI, and TCI state, as long as the functionality for applying it to multiple physical channels / signals simultaneously is applied.

[0081] The WTRU may be configured with a first mode for unified TCI (e.g., Separate DLU TCI mode), where the indicated unified TCI (e.g., first unified TCI or second unified TCI) may be applicable to the downlink (e.g., based on the first unified TCI) or the uplink (e.g., based on the second unified TCI).

[0082] In an example of a first mode, a WTRU may receive (e.g., from a base station) an indication of a first unified TCI to be used / applied for both a downlink control channel (e.g., PDCCH) and a downlink shared channel (e.g., PDSCH) (e.g., and a downlink RS). A source reference signal in the first unified TCI may provide common QCL information for at least WTRU-dedicated reception on the PDSCH and / or all or a subset of a control resource set (CORESET) in a component carrier (CC). In an example, a WTRU may receive (e.g., from a base station) an indication of a second unified TCI to be used / applied for both an uplink control channel (e.g., PUCCH) and an uplink shared channel (e.g., PUSCH) (e.g., and an uplink RS). A source reference signal in the second unified TCI may provide a reference for determining a common UL TX spatial filter for at least all or a subset of dedicated PUCCH resources in a PUSCH and CC based on a dynamic grant and / or a configured grant.

[0083] The WTRU may be configured with a second mode for unified TCI (e.g., JointTCI mode), wherein the indicated unified TCI (e.g., a third unified TCI, or in other words, a uTCI that is independent of the first and second unified TCIs referenced above) may be applicable to both the downlink and uplink (e.g., based on the third unified TCI).

[0084] In an example of a second mode, the WTRU may receive (e.g., from a base station) an indication of a second unified TCI to be used / applied commonly to PDCCH, PDSCH, PUCCH and / or PUSCH (e.g., and DL RS and / or UL RS).

[0085] In one case, for these two modes, namely the first mode (Separate DL ULTCI mode) and the second mode (JointTCI mode), only one of these modes can be used (e.g., configured by RRC), so the uTCI used for each mode may not be related to the uTCI of other modes at all.

[0086] The WTRU may determine the TCI state applicable for transmission or reception by first determining the unified TCI state instance applicable for transmission or reception, and then determining the TCI state corresponding to the unified TCI state instance. Transmission may include at least PUCCH, PUSCH and / or SRS. Reception may include at least PDCCH, PDSCH and / or CSI-RS. As used herein, a unified TCI state instance may also be referred to as a TCI state group, a TCI state process, a unified TCI pool, a set of TCI states, a time domain instance / stamp / time slot / symbol set and / or a frequency domain instance / RB / subband set, etc. A unified TCI state instance may be equivalent to or identified as a CORESET pool identifier (e.g., CORESETPoolIndex and / or TRP indicator, etc.).

[0087] As used herein, unless otherwise noted, a transmit and receive point (TRP) may be used interchangeably with one or more of a TP (transmit point), a RP (receive point), a RRH (radio remote head), a DA (distributed antenna), a BS (base station), a sector (of a BS), and / or a cell (e.g., a geographic cell area served by a BS). In the following, unless otherwise noted, multiple TRPs may be used interchangeably with one or more of an MTRP, an M-TRP, and multiple TRPs. In one case, a TRP may be a "remote antenna part / hardware" that may be connected (e.g., fiber optic cable, etc.) to a base station (e.g., a "gNB site"). In one case, if many TRPs are used at one base station, a "virtual cell" may be formed (e.g., per virtual cell per TRP), although those virtual cells may be associated with the same physical cell ID (PCID). In one case, there may be one TRP at a base station (e.g., where each TRP may be considered to be almost equivalent to a base station or a sector of a base station). In one case, the use of TRP can be applicable to a MIMO use case, and more specifically, to a portion of a base station of a wireless system.

[0088] The WTRU may be configured with or may receive configuration of one or more TRPs to which the WTRU may send and / or from which the WTRU may receive. The 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.

[0089] The WTRU may be configured with at least one RS for the purpose of channel measurement. The RS may be denoted as a channel measurement resource (CMR) and may include a CSI-RS, SSB, or other downlink RS sent from a TRP to the WTRU. The CMR may be configured with or associated with a TCI state. The WTRU may be configured with CMR groups, where CMRs sent from the same TRP may be configured. Each group may be identified by a CMR group index (e.g., group 1). The WTRU may be configured to have one CMR group per TRP, and the WTRU may receive a link between a CMR group index and another CMR group index, or a link between an RS index from one CMR group and another RS ​​index from another group.

[0090] The WTRU may be configured with or receive configuration of one or more path loss (PL) reference groups (e.g., sets) and / or one or more SRS groups, SRS resource indicators (SRIs), and / or SRS resource sets. The PL reference group may correspond to or may be associated with a TRP. The PL reference group may include, identify, correspond to, or be associated with one or more TCI states, SRIs, reference signal sets (e.g., CSI-RS sets, SRI sets), CORESET indexes, and or reference signals (e.g., CSI-RS, SSBs).

[0091] The WTRU may receive a configuration (e.g., any configuration described herein). The configuration may be received from a base station (e.g., a gNB or a TRP). For example, the WTRU may receive a configuration of one or more TRPs, one or more PL reference groups, and / or one or more SRI sets. The WTRU may implicitly determine the association between the RS set / group and the TRP. For example, if the WTRU is configured with two SRS resource sets, the WTRU may determine to transmit to TRP1 using the SRS in the first resource set and to transmit to TRP2 using the SRS in the second resource set. The configuration may be via RRC signaling.

[0092] As used herein, TRP, PL reference group, SRI group and / or SRI set may be used interchangeably. For example, a TRP may be identified as a DL transmitting entity associated with an RS belonging to a path loss (PL) reference group. For example, a TRP may be identified as a UL receiving entity associated with an SRS belonging to an SRS resource indicator (SRI) group. For example, a TRP may be identified as a UL receiving entity associated with an SRS resource set belonging to an SRI set.

[0093] The WTRU may report a subset of channel state information (CSI) components, where the CSI components may correspond to one or more of the following: a CSI-RS resource indicator (CRI), an SSB resource indicator (SSBRI), an indication of a panel for reception at the WTRU (e.g., a panel identifier or a group identifier), measurement results such as L1-RSRP, L1-SINR obtained from SSB or CSI-RS (e.g., cri-RSRP, cri-SINR, ssb-Index-RSRP, ssb-Index-SINR), and at least other channel state information such as a rank indicator (RI), a channel quality indicator (CQI), a precoding matrix indicator (PMI) and / or a layer index (LI).

[0094] The attributes of a grant or assignment may include one or more of the following: frequency allocation; aspects of time allocation, such as duration; priority; modulation and coding scheme; transport block size; number of spatial layers; number of transport blocks; TCI state, CRI or SRI; number of repetitions; whether the repetition scheme is type A or type B; whether the grant is a configured grant type 1, type 2 or a dynamic grant; whether the assignment is a dynamic assignment or a semi-persistent scheduled (configured) assignment; a configured grant index or a semi-persistent assignment index; the periodicity of the configured grant or assignment; channel access priority class (CAPC); and / or any parameters provided by the MAC or by the RRC in the DCI for scheduling the grant or assignment.

[0095] The indication through the DCI may include one or more of the following: an explicit indication through a DCI field or through an RNTI used to mask the CRC of the PDCCH; and / or an implicit indication through attributes such as the DCI format, DCI size, Coreset or search space, aggregation level, the first resource element of the received DCI (e.g., the index of the first control channel element), where the mapping between attributes and values ​​may be signaled by RRC or MAC.

[0096] In one method, the WTRU may receive at least one DCI (e.g., a first DCI and / or a second DCI, such as Figure 2The WTRU may generate a HARQ-ACK codebook (as shown), the at least one DCI may indicate at least one unified TCI (e.g., a first unified TCI and / or a second unified TCI). The HARQ-ACK codebook may (e.g., also) include at least one HARQ-ACK bit based on receiving a PDSCH such as scheduled by the first DCI and / or the second DCI. The HARQ-ACK codebook may include a joint HARQ-ACK for the MTRP PDSCH and at least one bit based on receiving at least one DCI indicating a unified TCI. For example, the WTRU may receive a first DCI with a first uTCI, a second DCI with a second uTCI, and an MTRP PDSCH; the WTRU may transmit an acknowledgment (ACK) of all received transmitted HARQ-ACK codebooks. Based on including / inserting / adding at least one separate bit in the HARQ-ACK codebook (e.g., joint HARQ-ACK for MTRP PDSCH), this can improve reliability and robustness by reducing the probability of mismatch between the WTRU and the base station when setting / applying a unified TCI (e.g., a first unified TCI and / or a second unified TCI), wherein the at least one separate bit can indicate whether the unified TCI indicated by at least one DCI is successfully received.

[0097] The WTRU may generate a HARQ-ACK codebook based on receiving at least one DCI that may indicate at least one unified TCI instance. In some cases, the WTRU may be configured to include or append at least one bit in the HARQ-ACK codebook to provide an indication or confirmation of receiving at least one unified TCI indication.

[0098] The WTRU may attach one bit for each configured unified TCI instance. If the WTRU receives at least one DCI containing an indication of a unified TCI instance, the WTRU may set the bit corresponding to the TCI instance to a first value, otherwise to a second value.

[0099] The WTRU may attach at least one bit indicating how many different unified TCI instances are indicated within the at least one DCI. For example, the WTRU may set the bit to a first value if a single unified TCI instance is indicated within the at least one DCI, and to a second value if two or more unified TCI instances are indicated. This may allow the scheduler to detect if the WTRU has missed all DCIs indicating unified TCI instances.

[0100] The WTRU may determine that it missed at least one DCI based on at least one counter downlink assignment index (DAI) and / or a total DAI value received from the at least one DCI. The WTRU may attach a bit to the HARQ-ACK codebook indicating whether the WTRU missed at least one DCI.

[0101] In the event that the WTRU determines that no DCI is missed or in the event that the WTRU receives an indication of more than one unified TCI instance, the WTRU may attach the bit set to the first value. Otherwise, the WTRU may attach the bit set to the second value.

[0102] The WTRU may determine whether to attach at least one bit based on the number of at least one DCI and the received counter DAI and / or total DAI value indicated in the at least one DCI. For example, if the number of at least one DCI is greater than N, the WTRU may attach at least one bit, where N is a predefined or configured number. For example, N may be one (1).

[0103] A WTRU may (e.g., be configured to) communicate with more than one TRP (e.g., MTRP). As used herein, for illustrative purposes, the more than one TRP may include TRP1 and TRP2, however, the proposed methods and processes may be equally (e.g., equivalently, extendedly, etc.) used for situations where more than two TRPs are used to communicate with the WTRU (for DL / UL). In an example, one of the MTRPs may be a primary TRP (e.g., TRP1).

[0104] Figure 2 An example of a separate ACK transmission for confirming the reception of a unified TCI is illustrated. In this scenario, there may be three entities: WTRU 203, TRP 201, and TRP 203. The arrows shown may indicate the transmission and the corresponding reception, and time may be shown on the horizontal axis of the figure. As shown in the example, WTRU 203 may receive a first DCI 211 indicating a first unified TCI (e.g., to be applied to multiple channels / signals), wherein the first DCI may (e.g., also) include a scheduling grant for a first PDSCH. The WTRU may receive a second DCI 213 indicating a second unified TCI (e.g., to be applied to multiple channels / signals), wherein the second DCI may (e.g., also) include a scheduling grant for a second PDSCH. WTRU 203 may transmit an ACK for each reception of a DCI including each uTCI (e.g., 212 shows ACK1 for successful reception of the first DCI (including reception of the first uTCI), and 214 shows ACK2 for successful reception of the second DCI (including reception of the second uTCI)). Typically, the ack may be for DCI, uTCI, and / or both.

[0105] The first PDSCH 215a and the second PDSCH 215b may be associated with each other as a MTRP PDSCH 215 (e.g., where the first PDSCH 215a may be sent from TRP 201 and the second PDSCH 215b may be sent from TRP 202). In some examples, the WTRU may send a joint HARQ-ACK 216 (e.g., ACK3) in response to receiving the first PDSCH and the second PDSCH, where the joint HARQ-ACK includes a first bit indicating whether the first PDSCH was successfully received and a second bit indicating whether the second PDSCH was successfully received.

[0106] In an example, sending a joint HARQ-ACK may (also) be interpreted as (e.g., may include / contain / imply) confirmation of successful reception of the first DCI notifying the first unified TCI. Sending a joint HARQ-ACK may (also) be interpreted as (e.g., may include / contain / imply) confirmation of successful reception of the second DCI notifying the second unified TCI. Sending a joint HARQ-ACK may (also) be interpreted as (e.g., may include / contain / imply) confirmation of successful reception of both the first DCI notifying the first unified TCI and the second DCI notifying the second unified TCI (e.g., no need for such a confirmation). Figure 2 212ACK1 and 213ACK2 as shown).

[0107] In an example, the WTRU may fail to receive one of the first DCI and the second DCI (e.g., due to blocking, severe shadowing due to an obstacle, and / or deep fading in the wireless channel, etc.). In response to not receiving (e.g., failing) one of the first DCI and the second DCI, the WTRU may send a joint HARQ-ACK including a bit indicating a NACK. The original sender (e.g., a TRP, a base station, etc.) may receive the joint HARQ-ACK including a bit indicating a NACK, where the sender may interpret the NACK (e.g., erroneously) as a failure to receive one of the first PDSCH and the second PDSCH, but cannot interpret the NACK due to a failure to receive one of the first DCI and the second DCI. Based on this interpretation, the sender may continue to communicate with the WTRU using the first unified TCI and the second unified TCI, but the WTRU may not be aware of one of the first unified TCI and the second unified TCI due to the failure to receive the unified TCI. Such communication errors may cause performance degradation of wireless communication between the sender and the WTRU. Therefore, there is a need to improve the robustness of the unified TCI indication for MTRP by implementing one or more improved and / or new confirmation mechanisms. For example, in the case of MDCI-MTRP with joint HARQ-ACK mode (ackNackFeedbackMode=joint) configured, and / or in the case of PDCCH repetition (e.g., PDSCH repetition is applied together). In addition, it is necessary to determine a reference to the beam application time (BAT) of the application configuration.

[0108] One approach to addressing this issue may be to have the WTRU (e.g., configured to) send a (e.g., separate) acknowledgement (e.g., message) in response to (e.g., successfully) receiving at least one of the first unified TCI and the second unified TCI, such as in conjunction with a joint or data-only HARQ-ACK transmission (e.g., such as Figure 2In an example, the WTRU may (e.g., be configured / instructed to) send a first ACK in response to (e.g., successfully) receiving a first unified TCI (e.g., indicated by a first DCI), which may be independent of a HARQ-ACK (e.g., a joint HARQ-ACK) sent in response to a PDSCH such as scheduled by the first DCI. The WTRU may (e.g., be configured / instructed to) send a second ACK in response to (e.g., successfully) receiving a second unified TCI (e.g., indicated by a second DCI), which may be independent of a HARQ-ACK (e.g., a joint HARQ-ACK) sent in response to a PDSCH such as scheduled by the second DCI. Based on the confirmation for unified TCI reception separate from the HARQ-ACK for data reception, this may improve reliability and robustness by reducing the probability of mismatch between the WTRU and the base station when setting / applying unified TCIs (e.g., the first unified TCI and / or the second unified TCI).

[0109] In some cases, an additional ACK may be used to confirm receipt of a unified TCI indication (e.g., in a DCI), where the additional ACK may have a similar format (e.g., uplink channel, resource, signal) as the HARQ-ACK for a PDSCH or semi-persistent scheduling (SPS) release.

[0110] When the WTRU receives a DCI scheduling a PDSCH, the WTRU may report a HARQ-ACK corresponding to the received PDSCH, and the reported HARQ-ACK may confirm successful reception of the PDSCH and / or the scheduling DCI. As used herein, a DCI scheduling a PDSCH or PUSCH may be used interchangeably with a scheduling DCI.

[0111] In one case, the WTRU may report an additional ACK when the scheduling DCI includes one or more of the following information and / or content, where the additional ACK may be a separate ACK that may be reported earlier than the HARQ-ACK associated with the scheduling data (e.g., PDSCH) from the scheduling DCI: a unified TCI; a unified TCI for more than one TRP; a unified TCI for a primary (or secondary) TRP; and / or a priority indicator (e.g., present when the DCI is for a URLLC use case). The WTRU may (e.g., be configured to) apply or use the indicated unified TCI after a first beam application time (BAT) parameter from receiving the DCI and / or sending the additional ACK. The first BAT parameter may be configured by the base station and / or reported from the WTRU as part of the WTRU capability parameters. The WTRU may (e.g., be configured to) apply or use the indicated unified TCI after a second beam application time (BAT) parameter from receiving the scheduling data and / or sending the HARQ-ACK. The second BAT parameter may be configured by the base station and / or reported from the WTRU as part of the WTRU capability parameters. The first BAT parameter may be the same as the second BAT parameter or the second BAT parameter may be used subsequently. The second BAT parameter may be different from (e.g., shorter than) the first BAT parameter.

[0112] As referenced herein, the additional ACKs may be used interchangeably as separate ACKs, first ACKs, unified TCI acknowledgements, unified TCI acknowledgement indications, DCI-ACKs, DCI acknowledgement ACKs, and / or conditional ACKs.

[0113] When the PDSCH scheduling offset is large, the additional ACK may provide a shorter time duration for applying a unified TCI (e.g., based on the first BAT and / or based on sending the additional ACK) and reduce erroneous reception of confirmation of beam indication.

[0114] In one case, when one or more predetermined (e.g., and / or configured) conditions are met, the WTRU may report an additional ACK, thereby reducing the uplink resource overhead for the additional ACK. These predetermined and / or configured one or more conditions may be used in combination of two or more or individually.

[0115] For example, one condition may include a case where the unified TCI indicated in the scheduling DCI is different from a previous (eg, currently used) unified TCI.

[0116] For example, one condition may include that the beam quality of the current common beam (e.g., unified TCI) is below a threshold. In one instance, the beam quality may be based on a beam measurement of a reference signal associated with the current common beam (e.g., an RS in QCL with the currently used unified TCI). In another instance, the beam quality may be determined based on the number of HARQ-ACKs (e.g., negative ACKs) that occurred in the most recent PDSCH reception or PUSCH transmission. The number of NACKs may be counted within a time window, where the time window may be configured or predetermined.

[0117] For example, a condition may include a situation where different values ​​of a WTRU-panel index (e.g., associated with an indicated uniform TCI) have been reported (e.g., within a time window Z). In one example, the WTRU may report / send a (e.g., preferred) WTRU-panel index and / or a preferred beam index (e.g., among multiple WTRU-panel indexes reported as part of the WTRU capabilities and / or configured from the gNB), such as via a beam reporting instance, where the reported WTRU-panel index may indicate a preferred WTRU-panel for communicating with the base station. For example, similar WTRU-panel related behaviors / indications / reporting may affect this condition.

[0118] For example, a condition may include satisfying at least one BFR-related condition (eg, after the WTRU transmits a BFR request, receives a BFR response, and / or receives a DCI via the BFR-CORESET).

[0119] For example, one condition may include that the PDSCH scheduling offset and / or the PUSCH scheduling offset is greater than a threshold (eg, the thresholds for PDSCH and PUSCH may have different values).

[0120] For example, one condition may include a case where the HARQ-ACK transmission timing (eg, for PDSCH) is greater than a threshold.

[0121] For example, one condition may include a case where the number of repetitions for PDSCH and / or PUSCH is greater than / less than a threshold.

[0122] For example, one condition may include a condition of the status of the HARQ-ACK for the scheduled PDSCH. For example, if a negative ACK (NACK) is determined for the scheduled PDSCH, an additional ACK is reported.

[0123] For example, one condition may include when sub-slot based PDSCH or PUSCH scheduling is used; therefore, low latency high reliability transmission may be required.

[0124] For example, one condition may include a case where a coverage enhancement mode of operation is used (eg, a coverage enhancement scheme including "TB (eg, transmit block) over multiple slots" (TBoMS) and DMRS time domain bundling is used).

[0125] For example, one condition may include a situation where a system parameter (eg, bandwidth, subcarrier spacing, CP length, etc.) is associated with an additional ACK transmission.

[0126] In one case, the WTRU may be instructed (e.g., explicitly / implicitly) to report an additional ACK. In such a case, one or more of the following may apply: the scheduling DCI may be scrambled with two RNTIs, wherein when the scheduling DCI is scrambled with a first RNTI, the WTRU may report an additional ACK, otherwise, the WTRU may skip reporting the additional ACK; an explicit bit field in the scheduling DCI may indicate a request for an additional ACK report; each unified TCI state may be configured to report or not report an additional ACK; and / or each TRP (e.g., based on a TRP indicator, a value of CORSETPoolIndex, etc.) may be associated with (e.g., configured with / indicated with) whether an additional ACK is to be reported by the WTRU when the WTRU receives (e.g., via DCI) a unified TCI indication (e.g., associated with a TRP such as a certain TRP in each TRP).

[0127] Figure 3 An example of a separate ACK transmission for confirming the reception of a unified TCI is illustrated. As shown, at 301, the WTRU may (e.g., be configured to) receive an indication of a first TCI state (e.g., as a unified TCI). At 302, the WTRU may receive a first PDCCH based on the first TCI state. The first PDCCH may carry a first DCI that schedules a first PDSCH and may indicate a second TCI state.

[0128] At 303 and / or 305, the WTRU may send an ACK. If a time duration associated with at least one of reception of the first PDSCH or transmission of HARQ feedback associated with the first PDSCH is determined to be greater than a threshold (e.g., which may be based on one or more predetermined and / or configured conditions as described herein), the WTRU may (e.g., be configured to) send an ACK (e.g., DCI-ACK 303 and / or 305) acknowledging receipt of the first DCI.

[0129] At 304, the WTRU may receive a first PDSCH based on the first TCI state. At 307, the WTRU may send HARQ feedback associated with the first PDSCH. In an example, a DCI-ACK (e.g., 305) may be sent before the HARQ feedback is sent (e.g., 307), which may provide benefits (e.g., in terms of latency reduction and / or robustness of beam or TCI updates) because a receiver (e.g., a base station) receiving the DCI-ACK (e.g., 305) does not need to wait for the HARQ-ACK to ensure that the WTRU successfully received the first DCI. In such a case, the WTRU may receive the second PDCCH before sending the HARQ feedback associated with the first PDSCH - this may be possible as a result of the techniques disclosed herein (e.g., in a conventional scenario, the base station needs to wait for the HARQ-ACK to use the second TCI state).

[0130] In some examples, the WTRU may (e.g., be configured to) apply or use a second TCI state (such as a unified TCI applicable to multiple channels and / or signals) based on sending a DCI-ACK after a beam application time (BAT) parameter after sending the DCI-ACK as a new beam application timeline (e.g., instead of after a BAT parameter after sending a HARQ-ACK as an old beam application timeline, which may reduce latency for beam or TCI updates). Explained another way, if the WTRU sends a DCI-ACK at time t1, the WTRU may start using / applying the second TCI state at t2, where t2=t1+BAT. The BAT parameter may be configured by the base station and / or reported from the WTRU as part of the WTRU capability parameters.

[0131] Sending an ACK (e.g., DCI-ACK 303 or 305) confirming receipt of the first DCI may (e.g., also) depend on when at least one of the following conditions is met: the second TCI state is different from the first TCI state; and / or the first TCI state and the second TCI state are unified TCI states, where the indicated unified TCI state applies to more than one channel type (e.g., more than one channel type and / or signal type). In one example, as shown at 310, if the time to receive the PDSCH or send the HARQ-ACK for the PDSCH is greater than a threshold, the WTRU may send an ACK (DCI-ACK) to confirm receipt of the DCI (e.g., the second TCI state).

[0132] At 308, when 306 does not occur, the WTRU may receive a second PDCCH carrying a second DCI, wherein the second PDCCH is received after sending the HARQ feedback and is received based on the second TCI state.

[0133] In some instances, the WTRU may (e.g., be further configured to) use a second PUCCH resource to send HARQ feedback and use a first PUCCH resource (e.g., where the first PUCCH resource may be determined based on a configuration or indication in the first DCI) to send an ACK (e.g., DCI-ACK) to confirm DCI reception.

[0134] Figure 4A An example of a separate ACK transmission for confirming the reception of a unified TCI is illustrated. As shown, at 401, the WTRU may (e.g., be configured to) receive an indication of a first TCI state (e.g., as a unified TCI). At 402, the WTRU may receive a first PDCCH based on the first TCI state, wherein the first PDCCH may carry a first DCI that schedules a first PDSCH and may indicate a second TCI state.

[0135] At 403 and / or 404, an ACK for the DCI may be transmitted, and when it is transmitted may depend on one or more conditions disclosed herein. Figure 4B As shown, in determining whether and when to transmit a DCI-ACK, the WTRU may determine whether the time duration between receiving the first DCI and sending the HARQ feedback associated with the first PDSCH is greater than a threshold (e.g., 411). If not, then no additional ACK may be sent (e.g., 412). If so, then the WTRU may send an ACK confirming the receipt of the first DCI (e.g., 413). In some instances, there may be additional conditions for sending a DCI-ACK (e.g., 414), such as: whether the second TCI state is different from the first TCI state; and / or whether the two TCI states (the first TCI state and the second TCI state) are the same TCI state.

[0136] At 404, the WTRU may receive a first PDSCH based on the first TCI state. At 407, the WTRU may send HARQ feedback associated with the first PDSCH. In an example, the DCI-ACK may be sent before the HARQ feedback is sent, which may provide benefits (e.g., in terms of latency reduction and / or robustness of beam or TCI updates) because a receiver (e.g., a base station) receiving the DCI-ACK does not need to wait for the HARQ-ACK in order to ensure that the WTRU successfully received the first DCI.

[0137] In some examples, the WTRU may (e.g., be configured to) apply or use a second TCI state (such as a unified TCI applicable to multiple channels and / or signals) based on sending a DCI-ACK after a beam application time (BAT) parameter after sending the DCI-ACK as a new beam application timeline (e.g., instead of after a BAT parameter after sending a HARQ-ACK as an old beam application timeline, which may reduce latency for beam or TCI updates). Explained another way, if the WTRU sends a DCI-ACK at time t1, the WTRU may start using / applying the second TCI state at t2, where t2=t1+BAT. The BAT parameter may be configured by the base station and / or reported from the WTRU as part of the WTRU capability parameters.

[0138] At 406, the WTRU may receive a second PDCCH carrying a second DCI, wherein the second PDCCH is received after sending the HARQ feedback and is received based on the second TCI state. It should be noted that 410 illustrates a time partition where the WTRU may use the first TCI state for DL ​​reception (e.g., as a unified TCI) or where the WTRU may use the second TCI state for DL ​​reception (e.g., after 410) (e.g., as a unified TCI).

[0139] The WTRU may (e.g., be further configured to) use a first PUCCH resource to send HARQ feedback and use a second PUCCH resource (e.g., where the second PUCCH resource may be determined based on a configuration or indication in the first DCI) to send an ACK (e.g., DCI-ACK) to confirm DCI reception.

[0140] In some cases, several PUCCH resource sets may be RRC-configured, where each resource set may contain several PUCCH resources (e.g., in NR systems). For example, up to 4 PUCCH resource sets may be configured, each containing at least 8 PUCCH resources. Then, for a PUCCH resource set containing 8 resources, a PUCCH resource indicator (PRI) indicated in the received DCI may select a PUCCH resource for transmission. In addition, for each PUCCH resource, up to 8 different spatial information may be configured, where only one spatial information may be activated for transmission by a MAC CE.

[0141] A WTRU may receive a dynamic indication to configure a common beam (e.g., unified TCI) for future transmission and possible reception. If the received indication is via DCI, the DCI may or may not contain a scheduling grant. From a base station operation perspective, it is important to know whether the WTRU has successfully received the indicated common beam (e.g., unified TCI). Therefore, it is important that the WTRU may be able to transmit an ACK (e.g., DCI-ACK) corresponding to a correctly decoded DCI containing the indicated common beam.

[0142] In multi-TRP operation, the WTRU may receive common beam information (e.g., a unified TCI) corresponding to each TRP link via at least one dynamic indication (such as a DCI).

[0143] In some cases involving a single DCI and multiple TRP indications, the WTRU may receive unified TCI information for each TRP link via a cross-TRP link indication. In a case involving a single DCI and multiple TRP indications, the unified TCI indication mechanism may be based on at least one of: a method in which the WTRU may receive a single DCI, which may include a first (e.g., unified) TCI and a second (e.g., unified) TCI corresponding to a first TRP link and a second TRP link, respectively; a method in which the WTRU may receive a single DCI including a single TCI and another implicit or explicit indication that determines whether the indicated TCI is applicable to the first or second TRP link (e.g., the DCI may include a single bit indication to indicate whether the indicated TCI is applicable to the first or second TRP link); and / or a method in which the WTRU may receive only a single DCI that includes a single TCI information corresponding to a TRP link derived from the DCI, wherein based on the determined TCI for the first link, the WTRU may determine the TCI for the second TRP link based on a pre-configured TCI association table, which TCI association table may be pre-configured by another dynamic indication (such as a MAC CE) or through a semi-static configuration (such as through RRC). In the TCI association table, for each indicated TCI for a first TRP link, a second TCI may correspond to a configured second TRP link.

[0144] In one case involving a single DCI and multiple TRP indications, the WTRU may use configured PUCCH resources (such as the PUCCH resources indicated by the PUCCH resource indicator (PRI) in the received DCI) to transmit an ACK to confirm the receipt of the DCI. For sending the indicated PUCCH resources, the WTRU may perform one or more of the following to select a spatial filter: if the WTRU transitions from a non-uniform TCI (e.g., TCI state, beam index or TCI for a separate channel / signal) to a uniform TCI state, the WTRU may use the most recent TCI state used within a configured time window, where the most recent TCI state may be associated with a most recent uplink transmission (such as PUCCH, SRS and / or PUSCH, etc.); the WTRU may use the TCI state corresponding to the CORESET of the received DCI as a source reference signal for determining the spatial beam (e.g., where the WTRU may use the TCI state associated with the CORESET only after a time window has passed); and / or the WTRU may use a pre-configured reference signal (e.g., CRI, SSBRI, etc.) as a default source reference signal for determining spatial information (e.g., for ACK transmission, such as for PUCCH resources).

[0145] In some cases involving multi-DCI multi-TRP indications, the WTRU may receive unified TCI information for each TRP link with or without cross-TRP link indications. In one case, the unified TCI indication mechanism may be based on at least one of the following: the WTRU may receive unified TCI information for each TRP link through independent indications made by more than one dynamic indication (such as DCI); the WTRU may only receive a single DCI that contains a single TCI information corresponding to the TRP link derived from the DCI (e.g., associated to CORSETPoolIndex=0), where based on the determined TCI for the first link, the WTRU may determine the TCI for the second TRP link based on a pre-configured TCI association table, which may be provided by another dynamic indication (e.g., MAC CE or pre-configured by semi-static configuration, for example, by RRC), wherein in the TCI association table, for each indicated TCI associated to a first CORSETPoolIndex (for example, a first TRP link), a second TCI corresponding to a second CORSETPoolIndex (for example, a second TRP link) is configured (for example, associated); in order to improve reliability, the WTRU may receive an independent dynamic indication (for example, DCI) for each TRP link, wherein each dynamic indication may include a first TCI and a second TCI corresponding to the first TRP link and the second TRP link, respectively, so that in the event of a decoding failure of one of the dynamic indications (for example, DCI), the WTRU may still be able to apply the received indication of a unified TCI state to the two TRP links.

[0146] In a case involving a multi-DCI multi-TRP indication, the WTRU may use one or more of the corresponding configured PUCCH resources to confirm the receipt of each received DCI. In a method where the WTRU may determine a unified TCI state for each TRP link independently of multiple dynamic indications (e.g., DCI), the WTRU may transmit a separate ACK to each TRP associated with each received DCI. In an example, the WTRU may send an ACK using the PUCCH resources indicated by the PRI in the first received DCI and the second received DCI. In an example, the first received DCI (e.g., from the first TRP) may include a first PRI field of the PRI, and the second received DCI (e.g., from the second TRP) may include a second PRI field of the PRI.

[0147] The WTRU may bundle multiple ACKs and send a single ACK as an acknowledgement of successful decoding and determination of the TCI (e.g., unified TCI) for each link. In some cases, the WTRU may be configured with more than one PUCCH resource. For example, the WTRU may be configured with three PUCCH resources, namely a first PUCCH resource, a second PUCCH resource, and a third PUCCH resource, wherein the first PUCCH resource may be used to send a bundled ACK, the second PUCCH resource may be used to send an ACK corresponding to the first DCI, and finally the third PUCCH resource may be used to send an ACK corresponding to the second DCI. After decoding the first DCI and determining the (unified) TCI for the first indication, if the WTRU may receive a second DCI with a TCI indication for other TRP links within a time window, the WTRU may use the first PUCCH resource to send an ACK to confirm successful reception of both TCI states. In some instances, the time window may be fixed or based on the capabilities reported by the WTRU (e.g., and / or configuration / indication from the gNB, e.g., for confirmation). Otherwise, if the WTRU successfully decodes the first DCI and does not receive or successfully decodes the second DCI, the WTRU may use the second PUCCH resource to confirm the TCI indication made by the first DCI. If the WTRU decodes the second DCI outside the time window and determines the TCI associated with the second TCI or fails to decode the first DCI, the WTRU may use the third configured PUCCH resource for ACK transmission.

[0148] The WTRU may determine the unified TCI state for two TRP links based on a single dynamic indication (e.g., DCI), and the WTRU may transmit a single ACK. For example, when the DCI carries only one TCI information, and the other TCI is determined by association (e.g., a table with CORSETPoolIndex association), or the received DCI contains a first TCI and a second TCI, the WTRU may transmit a single ACK to confirm the successful determination and / or update of the unified TCI state for the two TRP links. The WTRU may use the PUCCH resources indicated by the PRI in the received DCI for ACK transmission.

[0149] In a case involving multiple DCI multiple TRP indications, the WTRU may perform one or more actions for selecting a spatial filter for the transmission of the indicated PUCCH resources.

[0150] For example, for the selection of spatial filters, if the WTRU is transitioning from a non-uniform TCI state to a uniform TCI state, the WTRU may use the most recent TCI state for each TRP link within a configured time window. The most recent TCI state may be associated with the most recent uplink transmission (such as PUCCH, SRS, PUSCH, etc.). In one example, the time window may be fixed or based on the WTRU's reported capabilities.

[0151] For example, for the selection of the spatial filter, the WTRU may use the TCI state corresponding to the CORESET of the received DCI as the source reference signal for determining the spatial beam. In one example, the WTRU may use the TCI state associated to the CORESET only after a time window has passed.

[0152] For example, for the selection of a spatial filter, the WTRU may use a pre-configured reference signal (e.g., CRI, SSBRI, etc.) for each TRP link as a default source reference signal for determining spatial information.

[0153] In some cases, the WTRU may receive more than one PDCCH candidate carrying the same grant (e.g., DCI) content, where each candidate is transmitted in a TDM manner from a different TRP with a different spatial filter. The WTRU may receive each PDCCH candidate individually, or two candidates may be soft combined to improve decoder reliability. The grant may schedule PDSCH transmissions from a single TRP. The WTRU may transmit an ACK to confirm successful reception of the PDSCH. When the unified TCI command / indication is successfully received, the WTRU may transmit an ACK (e.g., a beam confirmation ACK).

[0154] Based on one or more techniques disclosed herein, multi-TRP PDCCH repetition candidates may carry a unified TCI, or carry a grant and a unified TCI. The WTRU may receive a grant from the PDCCH to schedule PDSCH from more than one TRP, where each TRP may be sent using a spatial filter (e.g., TCI). The WTRU may determine that the PDCCH and PDSCH repetitions are paired so that the spatial filters are associated between the repetition indices. For example, the WTRU may receive PDCCH candidate 1 with TCI1 and PDCCH candidate 2 with TCI2. The WTRU may then determine that PDSCH repetition 1 may be received using TCI1 and PDSCH repetition 2 may be received using TCI2.

[0155] In one case, for any PDCCH candidate repetition carrying a unified TCI, the WTRU may determine to transmit a beam acknowledgment ACK to confirm successful reception of the unified TCI. The WTRU may transmit the ACK after the first PDCCH candidate, the second PDCCH candidate, or both PDCCH candidates. The WTRU may receive a configuration for the PDCCH, which may include a configurable time offset K, and the WTRU may transmit the ACK after K seconds (e.g., time slots, symbols, or time units) have passed from the reference PDCCH candidate. The WTRU may use the time offset K as a starting reference to count the beam application time (BAT) for applying the unified TCI, and the WTRU may assume that the unified TCI is applied after the BAT. The WTRU may determine, for example, based on an indication / configuration from a base station (e.g., a gNB) whether the reference (PDCCH) candidate is a PDCCH candidate that starts earlier in time or a PDCCH candidate that ends later in time.

[0156] If the WTRU successfully decodes both PDCCH candidates individually, the WTRU may determine (eg, based on an indication / configuration from a base station) to transmit two ACKs. In this case, both candidates are references for their respective ACK timings.

[0157] Alternatively, the WTRU may transmit two ACKs and one PDCCH candidate may serve as a reference for both ACKs. The WTRU may also receive an inter-ACK timing offset in addition to the timing offset sent with respect to the reference PDCCH. The transmission of the second ACK may be delayed by as much as the inter-ACK timing offset with respect to the first ACK.

[0158] Alternatively, the WTRU may determine (e.g., based on an indication / configuration from a base station) to transmit only one ACK after the first successfully decoded PDCCH candidate (which may be the first PDCCH candidate or the second PDCCH candidate). In this case, the successfully decoded candidate is a reference for the ACK timing. If the WTRU also successfully decodes the second candidate, the WTRU may not transmit a second ACK.

[0159] If the WTRU receives using soft combining, the WTRU may transmit an ACK using a time offset calculated based on using the first candidate or the second candidate as a reference.

[0160] Alternatively, to a WTRU that transmits an ACK for a beam acknowledgement, the WTRU may transmit two ACKs, which may correspond to a unified TCI ACK and a PDSCH ACK. The WTRU may receive a configuration for a PUCCH with two PUCCH resources, where each PUCCH resource is configured for one type of ACK. The WTRU may receive a PUCCH resource indicator (PRI) code point in the DCI indicating two PRIs, or may explicitly indicate two PRI values. The WTRU may determine the frequency location of the PUCCH resource (e.g., RB index, number of RBs) based on the PRI. The network may implicitly determine the type of ACK based on the PRI selected by the WTRU for ACK reporting.

[0161] For example, when the WTRU successfully receives a PDSCH scheduled by a repeated PDCCH, the WTRU may transmit an ACK using the first PRI. When the WTRU successfully receives a unified TCI indication, the WTRU may transmit an ACK using the second PUCCH resource. Each PUCCH may have its own reference PDCCH candidate, or they may all use the same reference PDCCH candidate for timing with different time offsets per PUCCH resource.

[0162] The WTRU may use the second PUCCH resource to send a beam confirmation ACK only when one or more of the following conditions are met: the signal quality (RSRP, RSSI, SNR, SINR) of the current common beam (e.g., unified TCI) is lower than a threshold; the signal quality of the current common beam (e.g., unified TCI) is lower than the signal quality of the new beam; after the WTRU transmits a BFR request, receives a BFR response, and / or receives a DCI via a BFR-CORESET; based on recent (e.g., most recent) beam report content (e.g., if the WTRU's last reported beam measurement result is Y seconds before receiving the unified TCI command, and Y is less than a threshold, the WTRU may only send an ACK for the PDSCH instead of a second ACK for the unified TCI); based on a PDSCH scheduling offset (e.g., if the PDSCH is transmitted at a time greater than a threshold Y, the WTRU may transmit an ACK and apply a new unified TCI to the PDSCH); based on the HARQ-ACK transmission timing; and / or based on the number of PDSCH repetitions.

[0163] For example, if the WTRU determines that the PDSCH is scheduled with more than X (e.g., X=4) repetitions, the WTRU may transmit an ACK and apply a new uniform TCI for the repetitions that occur after the BAT. Each WTRU may receive a configuration of WTRU-specific PUCCH resources for uniform TCI ACK. In this case, no other WTRU may use the same PUCCH resources and collisions may not occur.

[0164] The WTRU may report both ACKs in a pre-configured ordering. For example, the WTRU may include a PDSCH ACK in a first PUCCH resource and a unified TCI ACK in a second PUCCH resource, or vice versa. The WTRU may receive a configured link between the PRI ordering in the DCI and the ACK usage type. Alternatively, the WTRU may dynamically determine the ordering based on one of the conditions highlighted above. For example, if the WTRU determines that the signal quality of the beam is below a threshold, the WTRU may determine to transmit a unified TCI ACK in a first PUCCH resource (e.g., a first PRI); otherwise, a second PRI is used. Similarly, for a time index, the WTRU may select the PUCCH that starts earliest / latest in time (e.g., with the lowest / highest PDCCH to HARQ offset) for the unified TCI ACK based on satisfying one or more of the conditions. In another example, the WTRU may determine to use a PUCCH resource with a repetition number that is higher than a threshold for a unified TCI ACK (e.g., a PRI with the highest repetition number).

[0165] Alternatively, more than one WTRU (e.g., a group of WTRUs within a cell, or all WTRUs within a cell) may receive a configuration for the same second PUCCH resource (e.g., one PUCCH resource for unified TCI ACK). Any WTRU from the group may send an ACK for the unified TCI using the shared PUCCH resource.

[0166] The WTRU may be configured with a timer and the WTRU may be configured with a counter that increments for each unified TCI ACK transmission. The WTRU may be limited to no more than Y unified TCI ACK transmissions within X (e.g., second) time periods. For example, the WTRU may use a PRI resource only Y times during X seconds. If the WTRU uses a PRI resource more than Y times, another PRI resource may be used. This may reduce congestion when multiple users share the same PUCCH resource.

[0167] The network (e.g., node, base station, etc.) may coordinate unified TCI indications to ensure that collisions may not occur on PUCCH resources. For example, one unified TCI indication may be sent to the WTRU. The network may not send a unified TCI indication for another WTRU until the network receives an ACK from the first unified TCI indication. The network may monitor the PUCCH resources for any WTRU configured in the group.

[0168] If the WTRU receives a configuration with only one PUCCH resource, and the WTRU determines that two ACKs (e.g., one for PDSCH and one for TCI indication) conflict (e.g., they have the same time occupancy), the WTRU may determine to transmit one ACK over the other based on a priority rule. For example, the WTRU may apply a priority rule where a unified TCI indication ACK has a higher priority than a PDSCH ACK. If the WTRU cannot multiplex more than one ACK in the UCI report, the WTRU may omit the ACK for the PDSCH and may only send the ACK for the unified TCI.

[0169] Figure 5 An example of reliability enhancement when receiving a DCI for a unified TCI is illustrated. For this example, there may be multiple TRPs (e.g., TRPs 501 and 502), WTRU 503. Time is illustrated on the horizontal axis. There may be coordination between TRP 501 and TRP 502. WTRU 503 may receive one or more configuration parameters for DCI reception behavior / mode when receiving at least one DCI indicating a unified TCI (e.g., to enhance reliability performance of a unified TCI for multiple TRPs (such as TRP 501 and TRP 502), such as having ideal backhaul coordination between the TRPs).

[0170] At 511, the WTRU 503 may (e.g., be configured to) receive a superposition of DCI 1 and DCI 2 from the TRP 501 at a certain time t1. The superposition of DCI 1 and DCI 2 (expressed as DCI 1=a, DCI 2=b) may be performed as DCI 1+DCI 2=a+b (e.g., at the complex baseband modulation level). A power scaling factor p may be used to comply with a transmit power specification / scaling, such as DCI 1+DCI 2=p(a+b).

[0171] At 512, WTRU 503 may also receive the difference of DCI 1 and DCI 2 from TRP2 at a certain time t2, which may be expressed as DCI 1–DCI 2=ρ(ab). The WTRU may perform the following procedure to estimate DCI 1 and DCI 2 as ρ(a+b)+ρ(ab)=(2ρ)a, ρ(a+b)-ρ(ab)=(2ρ)b.

[0172] Based on performing the procedure for estimating DCI 1 and DCI 2, the WTRU may transmit ACK 1 (e.g., 513) and ACK 2 (e.g., 514) (e.g., both on PUSCH, both on PUCCH, one on PUSCH and the other on PUCCH) to confirm the determination of DCI 1 and DCI 2. Alternatively, the WTRU may broadcast / send a common / single ACK (e.g., 515) (e.g., on PUSCH or PUCCH) to confirm the determination of DCI 1 and DCI 2. The common ACK (e.g., 515) may reduce overhead, and the reporting procedure may enhance the reliability performance of the unified TCI. This may reduce the signaling overhead associated with the transmission of an ACK in response to receiving at least one unified TCI. This may improve the reliability of the DCI transmission, such as based on (e.g., time) diversity when receiving DCI 1 and DCI 2.

[0173] In one case, a unified transmit configuration indicator (TCI) (e.g., joint or a pair of separate DL / UL) may be indicated / maintained at the WTRU to apply to both control channels / data channels simultaneously; this may be different from separate beam steering for each channel.

[0174] In one case, there may be a multi-DCI based MTRP (MDCI-MTRP) based on CORESETPoolIndex = 0 or 1 to support eMBB. In addition, based on the TCI state that associates up to two code points for the TCI field in the DCI, there may be a single DCI based MTRP (SDCI-MTRP) for repeated transmission across TRPs and for reliability enhancement.

[0175] In one case, there may be an extension of a unified TCI that may be an indication of multiple DL and UL TCI states focusing on multiple TRP use cases.

[0176] In response to (e.g., successfully) receiving at least one unified TCI indication by a DCI scheduling a PDSCH, the WTRU may send a separate acknowledgement (ACK) based on the HARQ-ACK for the PDSCH, wherein the separate ACK may be used to confirm the reception of the at least one unified TCI. The WTRU may send a separate ACK in response to (e.g., successfully) receiving at least one of a first unified TCI indicated by a first DCI scheduling a first PDSCH and a second unified TCI indicated by a second DCI scheduling a second PDSCH, wherein the separate ACK may be used to confirm the reception of the at least one unified TCI and is separate from the joint HARQ-ACK for the first PDSCH and the second PDSCH.

[0177] The WTRU may generate a HARQ-ACK codebook based on receiving at least one DCI that may indicate at least one unified TCI, wherein the HARQ-ACK codebook may include at least one HARQ-ACK bit based on receiving a PDSCH scheduled by the at least one DCI and at least one bit based on successfully receiving the at least one DCI indicating the unified TCI.

[0178] The WTRU may report a separate ACK when one or more predetermined (and / or configured) conditions are met, where the condition may include at least one of the following: the unified TCI indicated in the scheduling DCI is different from a previous (e.g., currently used) unified TCI; the beam quality of the current common beam (e.g., unified TCI) is below a threshold; at least one BFR-related condition is met; the PDSCH scheduling offset (and / or PUSCH scheduling offset) is greater than a threshold; the HARQ-ACK send timing (e.g., for PDSCH) is greater than a threshold; the number of repetitions for PDSCH (and / or PUSCH) is greater than a threshold; and / or if a negative ACK (NACK) is determined for the scheduled PDSCH.

[0179] In an example, the WTRU may receive an indication of a first TCI state (e.g., as a unified TCI). The WTRU may receive a first PDCCH based on the first TCI state, wherein the first PDCCH may carry a first DCI that schedules a first PDSCH and indicates a second TCI state. If a time duration associated with at least one of reception of the first PDSCH or transmission of HARQ feedback associated with the first PDSCH is determined to be greater than a threshold, the WTRU may send a DCI-ACK, thereby confirming receipt of the first DCI.

[0180] The WTRU may apply or use the second TCI state (as a unified TCI applicable to multiple channels and / or signals) as a new beam application timeline based on sending the DCI-ACK after the BAT parameters after sending the DCI-ACK.

[0181] In one case, a method may be implemented by a WTRU. The WTRU may receive an indication of a first TCI state. The WTRU may receive a first PDCCH transmission based on the first TCI state, wherein the first PDCCH transmission may include a first DCI. The first DCI may indicate scheduling information for a first PDCSCH and a second TCI state. The first DCI may also include timing for HARQ feedback associated with a first PDSCH. Based on determining that a time duration is greater than a threshold, the WTRU may transmit a DCI-ACK; the time duration may be a time period between receiving the PDCCH and receiving a scheduled reception of the first PDSCH reception or transmitting HARQ feedback associated with the first PDSCH. The DCI-ACK may confirm receipt of the first DCI. The DCI-ACK may be transmitted using a first PUCCH resource; the first PUCCH resource may be determined based on an RRC configuration or based on an indication in the first DCI. Transmitting DCI-ACK may also be based on: determining that the second TCI state is different from the first TCI state; and / or determining that the first TCI state and the second TCI state are unified TCI states; and / or determining that the first TCI state and the second TCI state are unified TCI states, wherein each unified TCI state in the unified TCI state may be applicable to more than one channel type. The WTRU may receive a first PDSCH based on the first TCI state. The WTRU may send HARQ feedback associated with the first PDSCH; the HARQ feedback may be transmitted using a second PUCCH resource; after sending the HARQ feedback, the WTRU may receive a second PDCCH based on the second TCI state, wherein the second PDCCH includes a second DCI.

[0182] Figure 6 An example process according to one or more techniques described herein is illustrated. At 601, a wireless transmit / receive unit (WTRU) may receive an indication of a first transmit configuration indicator (TCI) state. At 602, the WTRU may receive a first physical downlink control channel (PDCCH) transmission based on the first TCI state, wherein the first PDCCH transmission includes first downlink control information (DCI), and wherein the first DCI indicates scheduling information for a first physical downlink shared channel (PDSCH) and a second TCI state. Based on determining that a time duration is greater than a threshold (e.g., under this condition), the WTRU may transmit an acknowledgment (DCI-ACK) of the first DCI. In one instance, the DCI-ACK is transmitted to acknowledge receipt of the first DCI. In the same or another instance, the time duration may be a time period between receiving the PDCCH and scheduling reception of the first PDSCH reception and / or transmitting HARQ feedback associated with the first PDSCH.

[0183] As described herein, a higher layer may refer to one or more layers in a protocol stack, or a specific sublayer within a protocol stack. A protocol stack may include one or more layers in a WTRU or a network node (e.g., an eNB, a gNB, other functional entities, etc.), each of which may have one or more sublayers. Each layer / sublayer may be responsible for one or more functions. Each layer / sublayer may communicate directly or indirectly with one or more layers in other layers / sublayers. In some cases, the layers may be numbered, such as layer 1, layer 2, and layer 3. For example, layer 3 may include one or more of the following: non-access stratum (NAS), Internet protocol (IP), and / or radio resource control (RRC). For example, layer 2 may include one or more of the following: packet data convergence control (PDCP), radio link control (RLC), and / or medium access control (MAC). For example, layer 3 may include physical (PHY) layer type operations. The larger the number of a layer, the higher the layer is relative to other layers (e.g., layer 3 is higher than layer 1). In some cases, the foregoing examples may be referred to as layers / sublayers themselves, regardless of the layer number, and may be referred to as higher layers as described herein. For example, from highest to lowest, a higher layer may refer to one or more of the following layers / sublayers: a NAS layer, an RRC layer, a PDCP layer, an RLC layer, a MAC layer, and / or a PHY layer. Any reference to a higher layer in conjunction with a process, device, or system herein will refer to a layer higher than the layer of the process, device, or system. In some cases, references to a higher layer herein may refer to a function or operation performed by one or more layers described herein. In some cases, references to a higher layer herein may refer to information transmitted or received by one or more layers described herein. In some cases, references to a higher layer herein may refer to a configuration transmitted and / or received by one or more layers described herein.

[0184] Although features and elements are described above in specific combinations (e.g., embodiments, methods, examples, etc.), it will be understood by those of ordinary skill in the art that each feature or element may be used alone or in any combination with other features and elements. For example, as disclosed herein, for illustrative purposes, there may be a method described in conjunction with the accompanying drawings, and it will be understood by those of ordinary skill in the art that one or more features or elements from this method may be used alone or in combination with one or more features from another method described elsewhere. The symbol " / " (e.g., forward slash) may be used herein to represent "and / or", where, for example, "A / B" may imply "A and / or B". The terms "set" and "group" may be used interchangeably herein. In addition, the methods described herein may be implemented in a computer program, software, or firmware incorporated in a computer-readable medium for execution by a computer or processor. Examples of computer-readable media include electronic signals (sent via a wired or wireless connection) and 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 internal hard disks and removable disks), magneto-optical media, and optical media (such as CD-ROM disks and digital versatile disks (DVDs)). A processor in association with software may be used to implement a radio frequency transceiver for a WTRU, UE, terminal, base station, RNC, or any host computer.

Claims

1. A method implemented by a wireless transmit / receive unit (WTRU), the method comprising: receiving an indication of a first transmit configuration indicator (TCI) state; receiving a first physical downlink control channel (PDCCH) transmission based on the first TCI state, wherein the first PDCCH transmission includes first downlink control information (DCI), wherein the first DCI indicates scheduling information for a first physical downlink shared channel (PDSCH) and a second TCI state; and Under the condition that the time duration is greater than a threshold, transmitting an acknowledgement (DCI-ACK) for the first DCI, wherein transmitting the DCI-ACK acknowledges receipt of the first DCI, and wherein the time duration is a time period between receiving the PDCCH and scheduling reception of the first PDSCH reception or sending HARQ feedback associated with the first PDSCH.

2. The method according to claim 1, further comprising: The HARQ feedback associated with the first PDSCH is transmitted after transmitting the DCI-ACK, wherein the HARQ feedback is transmitted using a second physical uplink control channel (PUCCH) resource.

3. The method according to claim 1 or 2, wherein the DCI-ACK is transmitted using a first physical uplink control channel (PUCCH) resource, wherein the first PUCCH resource is determined based on an RRC configuration or based on an indication in the first DCI.

4. The method of any one of claims 1 to 3, wherein transmitting the DCI-ACK confirming receipt of the first DCI is further dependent on determining that the second TCI state is different from the first TCI state.

5. The method of any one of claims 1 to 4, wherein transmitting the DCI-ACK confirming receipt of the first DCI is further dependent on determining that the second TCI state is a unified TCI state, wherein the unified TCI state is applicable to more than one channel type.

6. The method according to any one of claims 1 to 5, further comprising: The first PDSCH is received based on the first TCI state.

7. A wireless transmit receive unit (WTRU), the WTRU comprising: means for receiving an indication of a first transmit configuration indicator (TCI) state; means for receiving a first physical downlink control channel (PDCCH) transmission based on the first TCI state, wherein the first PDCCH transmission comprises first downlink control information (DCI), wherein the first DCI indicates scheduling information for a first physical downlink shared channel (PDSCH) and a second TCI state; and means for transmitting an acknowledgment (DCI-ACK) of the first DCI under the condition that the time duration is greater than a threshold, wherein transmitting the DCI-ACK acknowledges receipt of the first DCI, and wherein the time duration is a time period between receiving the PDCCH and scheduling reception of the first PDSCH reception or sending HARQ feedback associated with the first PDSCH.

8. The WTRU of claim 7 further comprising: The HARQ feedback associated with the first PDSCH is transmitted after transmitting the DCI-ACK, wherein the HARQ feedback is transmitted using a second physical uplink control channel (PUCCH) resource.

9. The WTRU of claim 7 or 8, wherein the DCI-ACK is transmitted using a first physical uplink control channel (PUCCH) resource, wherein the first PUCCH resource is determined based on an RRC configuration or based on an indication in the first DCI.

10. The WTRU of any one of claims 7 to 9, wherein transmitting the DCI-ACK confirming receipt of the first DCI is further dependent on determining that the second TCI state is different from the first TCI state.

11. The WTRU of any one of claims 7 to 10, wherein transmitting the DCI-ACK confirming receipt of the first DCI is further dependent on determining that the second TCI state is a unified TCI state, wherein the unified TCI state is applicable to more than one channel type.

12. The WTRU of any one of claims 7 to 11, further comprising a means for receiving the first PDSCH based on the first TCI state.

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