Beam switching after listening first and then speaking

Abstract

Apparatus, methods, and systems for beam switching after a LBT process are disclosed. One apparatus (500) includes a processor (505) and a transceiver (525) operable on unlicensed spectrum, wherein the transceiver (525) supports multiple device panels. The processor (505) performs (805) a first Listen-Before-Speak (“LBT”) process using omnidirectional sensing to obtain a first Channel Occupied Time (“COT”), and in response to a successful LBT, performs (810) a first uplink transmission of a first transport block (“TB”) during the first COT using a first device panel. Here, the first uplink transmission uses a first portion of the first COT. The processor (505) performs (815) a directional LBT process for a second device panel to obtain the remainder of the first COT.

Description

[0001] Cross-references to related applications

[0002] This application claims priority to U.S. Provisional Patent Application No. 62 / 987,284, filed March 9, 2020, entitled “DIRECTIONAL LISTEN-BEFORE-TALK PROCEDURE,” which is incorporated herein by reference. This application also claims priority to Ankit Bhamri, Ali Ramadan Ali, Alexander Johann Maria Golitschek Edler von Elbwart, Karthikeyan Ganesan, and Joachim. International patent application PCT / IB2021 / 050693, filed January 29, 2021, entitled “PERFORMING A LISTEN-BEFORE-TALK ON BEAMS AND / OR PANELS,” claims priority to U.S. Provisional Patent Application 62 / 967,269, filed January 29, 2020, entitled “APPARATUSES, METHODS, AND SYSTEMS FOR FAST DIRECTIONAL LBT AT UE IN CONNECTED MODE,” filed by Ankit Bhamri, Ali Ramadan Ali, Alexander Johann Maria Golitschek Edler von Elbwart, Karthikeyan Ganesan, and Joachim Loehr, entitled “Apparatus, methods, and systems for fast directive LBT at UE in connected mode,” which is incorporated herein by reference. Technical Field

[0003] The topics disclosed in this article generally relate to wireless communication, and more specifically to directed listen-before-speak (“LBT”) processes, particularly for autonomous uplink communication using unlicensed spectrum. Background Technology

[0004] In some wireless communication systems, services are supplemented by operations on unlicensed spectrum. However, operations on unlicensed spectrum require a Clear Channel Assessment (“CCA”) prior to transmission, such as involving an LBT process.

[0005] In NR-U, channel access in both the downlink and uplink relies on CCA (e.g., LBT procedure) to obtain channel access. Before any transmission, the gNB and / or UE must first sense the channel to determine if there is any ongoing communication on the channel. In Release 16, beamforming is not considered for LBT in NR-U and only omnidirectional LBT is assumed. Summary of the Invention

[0006] A procedure for beam switching after the LBT process is disclosed. The procedure can be implemented by an apparatus, system, method, or computer program product.

[0007] A method of a user equipment (“UE”) includes performing a Listen-Before-Speak (“LBT”) procedure before a first timing of configured licensed (“CG”) resources, and, in response to a successful LBT during the first timing, performing an uplink (“UL”) transmission of a first transport block (“TB”) using a first beam. The method includes starting a timer in response to the UL transmission, determining that a UL transmission failure has occurred if no Hybrid Automatic Repeat Request (“HARQ”) acknowledgment (“ACK”) feedback is received within the duration of the timer, and, in response to determining that a UL transmission failure has occurred, switching to a second beam for subsequent UL transmissions of the first TB.

[0008] Another approach for the UE includes using omnidirectional sensing to perform a first LBT procedure to obtain a first channel occupancy time (“COT”) and, in response to a successful LBT during the first COT, performing a first UL transmission of a first TB using a first beam, wherein the first UL transmission uses a first portion of the first COT. A second approach includes performing a directional LBT procedure for a second beam to obtain the remainder of the first COT. Attached Figure Description

[0009] A more specific description of the embodiments briefly described above will be presented with reference to the specific embodiments illustrated in the accompanying drawings. It should be understood that these drawings depict only a few embodiments and are therefore not intended to limit the scope; the embodiments will be described and explained with additional specificity and detail using the drawings, in which:

[0010] Figure 1 This is a schematic block diagram illustrating one embodiment of a wireless communication system for beam switching after the LBT process;

[0011] Figure 2 This is a block diagram illustrating one embodiment of the 5G New Radio (“NR”) protocol stack;

[0012] Figure 3 This is a diagram illustrating one embodiment of a directional LBT prior to UL transmission;

[0013] Figure 4 This is a diagram illustrating one embodiment of a radio frame in which the LBT process is performed during its duration;

[0014] Figure 5 This is a diagram illustrating one embodiment of a user equipment apparatus that can be used for beam switching after the LBT process;

[0015] Figure 6 This is a diagram illustrating one embodiment of a network equipment device that can be used for beam switching after the LBT process;

[0016] Figure 7 This is a flowchart illustrating an embodiment of a first method for beam switching after the LBT process; and

[0017] Figure 8 This is a flowchart illustrating an embodiment of a second method for beam switching after the LBT process. Detailed Implementation

[0018] As those skilled in the art will understand, aspects of the embodiments can be embodied as a system, apparatus, method, or program product. Therefore, embodiments can take the form of a completely hardware embodiment, a completely software embodiment (including firmware, resident software, microcode, etc.), or an embodiment combining aspects of both software and hardware.

[0019] For example, the disclosed embodiments can be implemented as hardware circuitry that includes custom-designed very large-scale integration (“VLSI”) circuitry or gate arrays, off-the-shelf semiconductors such as logic chips, transistors, or other discrete components. The disclosed embodiments can also be implemented in programmable hardware devices such as field-programmable gate arrays, programmable array logic, programmable logic devices, etc. As another example, the disclosed embodiments may include one or more physical or logical blocks of executable code, which may, for example, be organized as objects, procedures, or functions.

[0020] Furthermore, embodiments may take the form of a program product embodied in one or more computer-readable storage devices that store machine-readable code, computer-readable code, and / or program code, hereinafter referred to as code. The storage device may be tangible, non-transitory, and / or non-transferable. The storage device may not embody signals. In one embodiment, the storage device employs only signals for accessing the code.

[0021] Any combination of one or more computer-readable media may be used. A computer-readable medium may be a computer-readable storage medium. A computer-readable storage medium may be a storage device for storing code. A storage device may be, for example, but not limited to, electronic, magnetic, optical, electromagnetic, infrared, holographic, micromechanical, or semiconductor systems, apparatuses, or devices, or any suitable combination thereof.

[0022] More specific examples of storage devices (a non-exhaustive list) will include the following: electrical connections having one or more wires, portable computer floppy disks, hard disks, random access memory (“RAM”), read-only memory (“ROM”), erasable programmable read-only memory (“EPROM” or flash memory), portable compact disc read-only memory (“CD-ROM”), optical storage devices, magnetic storage devices, or any suitable combination of the foregoing. In the context of this document, a computer-readable storage medium can be any tangible medium capable of containing or storing a program for use by or in conjunction with an instruction execution system, apparatus, or device.

[0023] The code used to perform the operations of the embodiments can be any number of lines and can be written in any combination of one or more programming languages, including object-oriented programming languages ​​such as Python, Ruby, Java, Smalltalk, and C++, and traditional procedural programming languages ​​such as the "C" programming language, and / or machine languages ​​such as assembly language. The code can be executed entirely on the user's computer, partially on the user's computer, as a standalone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In the latter scenario, the remote computer can be connected to the user's computer via any type of network including a local area network ("LAN"), a wireless LAN ("WLAN"), or a wide area network ("WAN"), or can be connected to an external computer (e.g., via the Internet through an Internet service provider ("ISP").

[0024] Furthermore, the features, structures, or characteristics described in the embodiments can be combined in any suitable manner. Numerous specific details, such as examples of programming, software modules, user selection, network transactions, database queries, database structures, hardware modules, hardware circuits, hardware chips, etc., are provided in the following description to provide a thorough understanding of the embodiments. However, those skilled in the art will recognize that the embodiments can be practiced without one or more of these specific details or using other methods, components, materials, etc. In other instances, well-known structures, materials, or operations have not been shown or described in detail to avoid obscuring aspects of the embodiments.

[0025] Throughout this specification, references to "an embodiment," "embodiment," or similar language mean that a particular feature, structure, or characteristic described in connection with that embodiment is included in at least one embodiment. Therefore, unless expressly stated otherwise, the phrases "in an embodiment," "in an embodiment," and similar language throughout this specification may, but do not necessarily, refer to the same embodiment, but rather mean "one or more, but not all, embodiments." Unless expressly stated otherwise, the terms "comprising," "including," "having," and variations thereof mean "including, but not limited to,". Unless expressly stated otherwise, the list of enumerated items does not imply that any or all items are mutually exclusive. Unless expressly stated otherwise, the terms "a," "an," and "the" also mean "one or more."

[0026] As used herein, a list containing the conjunction “and / or” includes any single item in the list or a combination of items in the list. For example, a list of A, B, and / or C includes only A, only B, only C, a combination of A and B, a combination of B and C, a combination of A and C, or a combination of A, B, and C. As used herein, a list using the term “one or more of…” includes any single item in the list or a combination of items in the list. For example, one or more of A, B, and C includes only A, only B, only C, a combination of A and B, a combination of B and C, a combination of A and C, or a combination of A, B, and C. As used herein, a list using the term “one of…” includes one and only one of any single item in the list. For example, “one of A, B, and C” includes only A, only B, or only C and excludes combinations of A, B, and C. As used herein, “selected from the group consisting of A, B, and C” includes one and only one of A, B, or C and excludes combinations of A, B, and C. As used in this article, “selecting members of a group consisting of A, B, and C and their combinations” includes only A, only B, only C, combinations of A and B, combinations of B and C, combinations of A and C, or combinations of A, B, and C.

[0027] The following description of various aspects of the embodiments is based on schematic flowcharts and / or block diagrams of methods, apparatus, systems, and program products according to the embodiments. It will be understood that individual blocks in the schematic flowcharts and / or block diagrams, as well as combinations of blocks in the schematic flowcharts and / or block diagrams, can be implemented by code. This code can be provided to a processor of a general-purpose computer, special-purpose computer, or other programmable data processing apparatus to produce a machine, such that instructions executed via the processor of the computer or other programmable data processing apparatus create means for implementing the functions / actions specified in the flowcharts and / or block diagrams.

[0028] The code can also be stored in a storage device that can instruct a computer, other programmable data processing device or other device to operate in a particular manner, such that the instructions stored in the storage device produce an article of art including instructions that implement the functions / actions specified in the flowchart and / or block diagram.

[0029] The code may also be loaded onto a computer, other programmable data processing apparatus or other device to cause a series of operational steps to be performed on the computer, other programmable apparatus or other device, thereby producing a computer-implemented process, such that the code executing on the computer or other programmable apparatus provides a process for implementing the functions / actions specified in the flowchart and / or block diagram.

[0030] The flowcharts and / or block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of apparatus, systems, methods, and program products according to various embodiments. In this regard, each block in the flowcharts and / or block diagrams may represent a module, segment, or portion of code, which includes one or more executable instructions for implementing one or more specified logical functions.

[0031] It should also be noted that in some alternative implementations, the functions marked in the boxes may not appear in the order shown in the figures. For example, two boxes shown consecutively may actually be executed substantially simultaneously, or these boxes may sometimes be executed in reverse order, depending on the functionality involved. Other steps and methods that are equivalent in function, logic, or effect to one or more boxes or portions thereof shown in the figures can be contemplated.

[0032] While various arrow and line types may be used in flowcharts and / or block diagrams, they are not intended to limit the scope of the corresponding embodiments. In practice, some arrows or other connectors may be used only to indicate the logical flow of the depicted embodiment. For example, an arrow may indicate a waiting or monitoring period of unspecified duration between enumerated steps of a depicted embodiment. It will also be noted that each block in a block diagram and / or flowchart, and combinations of blocks in block diagrams and / or flowcharts, can be implemented by a system based on dedicated hardware or a combination of dedicated hardware and code that performs the specified function or action.

[0033] The description of the elements in each figure can be referenced to the elements in the preceding figures. In all figures, the same reference numerals refer to the same elements, including alternative embodiments of the same elements.

[0034] Generally, this disclosure describes systems, methods, and apparatuses for beam switching after a LBT process. This disclosure addresses, but is not limited to, channel access mechanisms for unlicensed frequency bands in the high-frequency range (i.e., FR2 or FR4). More specifically, since beam-based operation is assumed to be for unlicensed spectrum at and beyond FR2, it is crucial to perform a listen-before-speak (“LBT”) in one or more specific beam directions rather than an omnidirectional LBT.

[0035] This disclosure describes panel handover during LBT failure at the UE side in connected mode and provides a solution for enabling faster channel access for AUL by switching beams / panels based on LBT failure at the UE in connected mode and considering interference / LBT failure at the gNB side. Essentially, it addresses how to facilitate the UE's autonomous handover from one panel / beam to another to perform faster LBT if LBT failure exists in a specific panel / beam direction. Alternatively, it addresses how to enable parallel LBT using multiple panels simultaneously for AUL.

[0036] In NR-U, channel access in both the downlink and uplink relies on LBT (Low-band Beamforming); however, in version 16, NR-U's LBT does not consider beamforming and assumes only omnidirectional LBT. The NR-U LBT process for channel access can be summarized as follows:

[0037] Both gNB-initiated Channel Occupancy Time (“COT”) and UE-initiated COT use Category 4 (“Cat-4”) LBT, where the start of a new transmission burst always executes an LBT with exponential backoff. Exceptions are made only when the duration of the DRS must be at most one ms and not multiplexed with a unicast PDSCH. As used herein, a Cat-4 LBT procedure refers to an LBT with random backoff and a variable-size contention window.

[0038] UL transmissions within a COT initiated by a gNB or subsequent DL transmissions within a COT initiated by a UE or gNB can be transmitted immediately without sensing, provided the interval between transmissions and the end of the previous transmission is no greater than 16 μs. Otherwise, Category 2 (“Cat-2”) LBTs must be used and the interval cannot exceed 25 μs. As used herein, a Cat-2 LBT procedure refers to an LBT without random backoff.

[0039] In various embodiments, the UE may include multiple antenna panels. Identifiers (IDs) that can be used at least to indicate panel-specific UL transmissions are supported. The possibility of reusing / modifying Rel-15 specification-supported IDs or introducing new IDs can be considered when defining IDs. In some embodiments, the UE does not need to explicitly expose its UL antenna panel implementation. In other embodiments, UE capability signaling may be used for panel-specific UL transmissions.

[0040] The panel identifier (panel ID) used to indicate a panel-specific UL transmission may include one of the following: 1) an SRS resource set ID; 2) an ID directly associated with a reference RS resource and / or resource set; 3) an ID that can be assigned to a target RS resource and / or resource set; and 4) an ID additionally configured in the spatial relationship information. The panel ID (excluding the reuse of existing IDs) can be used for panel-selection-based transmissions of PUSCH, PUCCH, and SRS across multiple active panels.

[0041] In some embodiments, multiple panels are implemented on the UE, and only one panel can be activated at a time using a predetermined panel switching / activation delay. In some embodiments, multiple panels are implemented on the UE, and multiple panels can be activated at once, with one or more panels available for transmission. In some embodiments, multiple panels are implemented on the UE, and multiple panels can be activated at once, but only one panel can be used for transmission. Note that this does not require the UE to always activate multiple panels simultaneously. Also note that the UE can control panel activation / deactivation.

[0042] In other embodiments, a new panel ID can be used, which can be implicitly / explicitly applied to transmissions for a target RS resource or resource set, for a PUCCH resource, or for an SRS resource. In such embodiments, the new panel ID is used implicitly (e.g., via DL beam reporting enhancement) or explicitly to perform panel-specific signaling. If explicitly signaled, the ID can be configured in the target RS / channel or reference RS (e.g., in the DL RS resource configuration or in spatial relation information).

[0043] As used herein, "UE panel" refers to a logical entity that can be mapped to a physical UE antenna. Under certain conditions, the gNB can assume that the mapping between the UE's physical antenna and the logical entity "UE panel" activated for transmission will not change. Depending on the UE's own implementation, the "UE panel" can have at least the following functionalities as an operating role of an antenna group unit to independently control its Tx beam.

[0044] The first problem addressed by this disclosure concerns how to handle UL Tx failures during multi-panel operation using spatial LBTs. This disclosure provides several solutions for panel switching during LBT failures on the UE side in connected mode, and provides solutions for allowing faster channel access for Autonomous Uplink (“AUL”) transmissions by switching beams / panels based on LBT failures at the UE in connected mode and considering interference / LBT failures at the gNB side.

[0045] This disclosure provides solutions on how to facilitate a UE's autonomous switching from one panel / beam to another to perform a faster LBT in the event of an LBT failure in a specific panel / beam direction. This disclosure also provides solutions on how to allow parallel LBT using multiple panels simultaneously for AUL (Automatic Power Requirement).

[0046] The second problem addressed by this disclosure concerns beam / panel handover initiated by the UE during the same channel occupancy time (“COT”). This disclosure provides a solution for how to acquire the remainder of the COT during multi-panel operation using spatial LBTs.

[0047] Figure 1 A wireless communication system 100 for beam switching after a LBT process, according to embodiments of the present disclosure, is depicted. In one embodiment, the wireless communication system 100 includes at least one remote unit 105, a radio access network (“RAN”) 120, and a mobile core network 140. The RAN 120 and the mobile core network 140 form a mobile communication network. The RAN 120 may consist of a base station unit 121, and the remote unit 105 communicates with the base station unit 121 using a wireless communication link 123. Although in Figure 1 The document depicts a specific number of remote units 105, base station units 121, wireless communication links 123, RAN 120, and mobile core network 140, but those skilled in the art will recognize that any number of remote units 105, base station units 121, wireless communication links 123, RAN 120, and mobile core network 140 can be included in the wireless communication system 100.

[0048] In one implementation, RAN 120 conforms to the 5G system specified in the 3GPP specification. For example, RAN 120 may be an NG-RAN that implements the NR RAT and / or LTE RAT. In another example, RAN 120 may include a non-3GPP RAT (e.g., Or an IEEE 802.11 series compliant WLAN. In another embodiment, RAN 120 conforms to the LTE system specified in the 3GPP specification. However, more generally, the wireless communication system 100 can implement some other open or proprietary communication networks, such as Global Microwave Access Interoperability (“WiMAX”) or the IEEE 802.16 series standards, as well as other networks. This disclosure is not intended to be limited to any particular wireless communication system architecture or protocol implementation.

[0049] In one embodiment, remote unit 105 may include computing devices such as desktop computers, laptop computers, personal digital assistants (“PDAs”), tablet computers, smartphones, smart TVs (e.g., internet-connected TVs), smart appliances (e.g., internet-connected appliances), set-top boxes, game consoles, security systems (including security cameras), in-vehicle computers, network devices (e.g., routers, switches, modems), etc. In some embodiments, remote unit 105 includes wearable devices such as smartwatches, fitness bands, optical head-mounted displays, etc. Furthermore, remote unit 105 may be referred to as UE, subscriber unit, mobile device, mobile station, user, terminal, mobile terminal, fixed terminal, subscriber station, user terminal, wireless transmit / receive unit (“WTRU”), device, or other terms used in the art. In various embodiments, remote unit 105 includes a subscriber identity and / or identification module (“SIM”) and a mobile device (“ME”) that provides mobile terminal functions (e.g., radio transmission, handover, voice encoding and decoding, error detection and correction, signaling to the SIM, and access). In some embodiments, the remote unit 105 may include a terminal device (“TE”) and / or be embedded in an appliance or device (e.g., a computing device as described above).

[0050] Remote unit 105 can communicate directly with one or more base station units 121 in RAN 120 via uplink (“UL”) and downlink (“DL”) communication signals. Additionally, UL and DL communication signals can be carried on wireless communication link 123. Here, RAN 120 is an intermediate network providing remote unit 105 with access to the mobile core network 140. As described in more detail below, RAN 120 can send measurement and reporting configuration 111 to remote unit 105, wherein remote unit 105 sends measurement reports 113 to RAN 120.

[0051] In some embodiments, remote unit 105 communicates with application server 151 via a network connection to mobile core network 140. For example, application 107 in remote unit 105 (e.g., a web browser, media client, telephone, and / or Voice over Internet Protocol (“VoIP”) application) can trigger remote unit 105 to establish a Protocol Data Unit (“PDU”) session (or other data connection) with mobile core network 140 via RAN 120. Mobile core network 140 then uses the PDU session to relay services between remote unit 105 and application server 151 in the packet data network. The PDU session represents a logical connection between remote unit 105 and user plane function (“UPF”) 141.

[0052] To establish a PDU session (or PDN connection), remote unit 105 must register with mobile core network 140 (also referred to as "attached to mobile core network" in the context of fourth-generation ("4G") systems). Note that remote unit 105 may establish one or more PDU sessions (or other data connections) with mobile core network 140. Therefore, remote unit 105 may have at least one PDU session for communicating with packet data network 150. Remote unit 105 may establish additional PDU sessions for communicating with other data networks and / or other communication peers.

[0053] In the context of a 5G system (“5GS”), the term “PDU session” refers to a data connection that provides end-to-end (“E2E”) user plane (“UP”) connectivity between remote unit 105 and a specific data network (“DN”) via UPF 141. A PDU session supports one or more Quality of Service (“QoS”) streams. In some embodiments, a one-to-one mapping may exist between QoS streams and QoS profiles, such that all packets belonging to a particular QoS stream have the same 5G QoS identifier (“5QI”).

[0054] In 4G / LTE systems, such as Evolved Packet System (“EPS”), a Packet Data Network (“PDN”) connection (also known as an EPS session) provides end-to-end (E2E) connectivity between the remote unit and the PDN. The PDN connectivity process establishes an EPS bearer, i.e., a tunnel between the remote unit 105 and the packet gateway (“PGW”, not shown) in the mobile core network 140. In some embodiments, a one-to-one mapping exists between the EPS bearer and the QoS profile, such that all packets belonging to a particular EPS bearer have the same QoS class identifier (“QCI”).

[0055] Base station unit 121 may be distributed over a geographical area. In some embodiments, base station unit 121 may also be referred to as an access terminal, access point, base station, base station, node B (“NB”), evolved Node B (abbreviated as eNodeB or “eNB”, also known as Evolved Universal Terrestrial Radio Access Network (“E-UTRAN”) node B), 5G / NR node B (“gNB”), home node B, relay node, RAN node, or any other term used in the art. Base station unit 121 is typically part of a RAN such as RAN 120, which may include one or more controllers communicatively coupled to one or more corresponding base station units 121. These and other elements of the radio access network are not shown, but are generally known to those skilled in the art. Base station unit 121 is connected to mobile core network 140 via RAN 120.

[0056] Base station unit 121 can serve multiple remote units 105 within its service area, such as a cell or cell sector, via wireless communication link 123. Base station unit 121 can communicate directly with one or more remote units 105 via communication signals. Typically, base station unit 121 transmits DL communication signals to serve remote units 105 in the time, frequency, and / or spatial domains. Furthermore, DL communication signals can be carried on wireless communication link 123. Wireless communication link 123 can be any suitable carrier in licensed or unlicensed radio spectrum. Wireless communication link 123 facilitates communication between one or more remote units 105 and / or one or more base station units 121. Note that during NR-U operation, base station unit 121 and remote units 105 communicate via unlicensed radio spectrum.

[0057] In one embodiment, the mobile core network 140 is a 5GC or Evolved Packet Core (“EPC”), which can be coupled to a packet data network 150, such as the Internet and private data networks, as well as other data networks. The remote unit 105 may have a subscription or other account with respect to the mobile core network 140. Each mobile core network 140 belongs to a single PLMN. This disclosure is not intended to limit implementation to any particular wireless communication system architecture or protocol.

[0058] Mobile core network 140 includes several network functions (“NFs”). As depicted, mobile core network 140 includes at least one UPF 141. Mobile core network 140 also includes multiple control plane functions (“CPs”), which include, but are not limited to, access and mobility management functions (“AMFs”) 143, session management functions (“SMFs”) 145, policy control functions (“PCFs”) 147, and unified data management functions (“UDMs”) serving RAN 120. In some embodiments, the UDM is quasi-co-located with a user data repository (“UDR”), which is described as a combined entity “UDM / UDR” 149. In various embodiments, mobile core network 140 may also include authentication server functions (“AUSFs”), network repository functions (“NRFs”) (used by various NFs to discover and communicate with each other via application programming interfaces (“APIs”), or other NFs defined for 5GC. In some embodiments, mobile core network 140 may include an authentication, authorization, and accounting (“AAA”) server.

[0059] In various embodiments, the mobile core network 140 supports different types of mobile data connections and different types of network slices, wherein each mobile data connection utilizes a specific network slice. Here, a "network slice" refers to a portion of the mobile core network 140 optimized for a specific service type or communication service. A network instance may be identified by a single network slice selection aid information ("S-NSSAI"), while the set of network slices authorized for use by the remote unit 105 is identified by network slice selection aid information ("NSSAI"). Here, "NSSAI" refers to a vector value including one or more S-NSSAI values. In some embodiments, various network slices may include separate instances of network functions, such as SMF 145 and UPF 141. In some embodiments, different network slices may share some common network functions, such as AMF 143. For illustration purposes, Figure 1 Different network slices are not shown, but their support is assumed.

[0060] Despite Figure 1A specific number and type of network functions are described, but those skilled in the art will recognize that any number and type of network functions can be included in the mobile core network 140. Furthermore, in an LTE variant of the EPC where the mobile core network 140 is the EPC, the described network functions can be replaced by appropriate EPC entities, such as a Mobility Management Entity (“MME”), Serving Gateway (“SGW”), PGW, Home Subscriber Server (“HSS”), etc. For example, AMF 143 can be mapped to the MME, SMF 145 can be mapped to the control plane portion of the PGW and / or mapped to the MME, UPF 141 can be mapped to the SGW and the user plane portion of the PGW, UDM / UDR 149 can be mapped to the HSS, etc.

[0061] Although Figure 1 The components of the 5G RAN and 5G core network are described, but the described embodiments for beam switching after the LBT process are applicable to other types of communication networks and RATs, including IEEE 802.11 variants, Global System for Mobile Communications (“GSM”, i.e., 2G digital cellular networks), General Packet Radio Service (“GPRS”), General Mobile Telecommunications System (“UMTS”), LTE variants, CDMA 2000, Bluetooth, ZigBee, Sigfox, and others.

[0062] During initial access or in a connection mode using SRI, remote unit 105 is configured with multiple UE panels. As used herein, "UE panel" refers to a logical entity that can be mapped to a physical UE antenna. Under certain conditions, the gNB can assume that the mapping between the UE's physical antenna and the logical entity "UE panel" activated for transmission will not change. Depending on the implementation of remote unit 105, the "UE panel" can at least have the functionality of operating as an antenna group unit to independently control its Tx beam.

[0063] According to the first solution, remote unit 105 handles UL Tx failures by switching to a different panel / beam and using licensed resources with the same configuration.

[0064] According to the second solution, remote unit 105 handles UL Tx failures by switching to different panels / beams, where different panels / beams have different configured licensed resources.

[0065] According to the third solution, remote unit 105 handles UL Tx failures by performing LBT on multiple panels / beams and selecting only one panel / beam for UL transmission. Here, multiple panels / beams use the same configured licensed resources.

[0066] According to the third solution, remote unit 105 handles UL Tx failures by performing LBT on multiple panels / beams and selecting only one panel / beam for UL transmission. Here, multiple panels / beams use licensed resources with different configurations. Furthermore, remote unit 105 selects multiple panels / beams for UL transmission.

[0067] According to the second solution, remote unit 105 handles UL Tx failures by switching to different panels / beams, where different panels / beams have different configured licensed resources.

[0068] In the following description, the term "RAN node" is used for a base station, but it can be replaced by any other radio access node, such as a gNB, eNB, base station ("BS"), access point ("AP"), etc. Furthermore, the operation is primarily described in the context of 5G NR. However, the proposed solution / method is equally applicable to other mobile communication systems that support measurement reporting in non-public networks.

[0069] Figure 2 An NR protocol stack 200 according to an embodiment of this disclosure is depicted. Although Figure 2 The diagram shows UE 205, RAN node 210, and AMF 215 in the 5G core network (“5GC”), but these represent a collection of remote units 105 that interact with base station unit 121 and mobile core network 140. As depicted, protocol stack 200 includes user plane protocol stack 220 and control plane protocol stack 225. User plane protocol stack 220 includes physical (“PHY”) layer 230, media access control (“MAC”) sublayer 235, radio link control (“RLC”) sublayer 240, packet data convergence protocol (“PDCP”) sublayer 245, and service data adaptation protocol (“SDAP”) layer 250. Control plane protocol stack 225 includes physical layer 230, MAC sublayer 235, RLC sublayer 240, and PDCP sublayer 245. Control plane protocol stack 225 also includes radio resource control (“RRC”) layer 255 and non-access stratum (“NAS”) layer 260.

[0070] The AS layer (also referred to as the "AS protocol stack") for the user plane protocol stack 220 consists of at least SDAP, PDCP, RLC, and MAC sublayers, as well as a physical layer. The AS layer for the control plane protocol stack 225 consists of at least RRC, PDCP, RLC, and MAC sublayers, as well as a physical layer. Layer 2 ("L2") is divided into SDAP, PDCP, RLC, and MAC sublayers. Layer 3 ("L3") includes the RRC sublayer 255 and NAS layer 260 for the control plane and includes, for example, an Internet Protocol ("IP") layer or a PDU layer (not depicted) for the user plane. L1 and L2 are referred to as "lower layers," while L3 and higher layers (e.g., transport layer, application layer) are referred to as "higher layers" or "upper layers."

[0071] Physical layer 230 provides a transport channel to MAC sublayer 235. As described herein, physical layer 230 can perform CCA / LBT procedures. In some embodiments, physical layer 230 can send a notification of UL LBT failure to the MAC entity at MAC sublayer 235. MAC sublayer 235 provides a logical channel to RLC sublayer 240. RLC sublayer 240 provides an RLC channel to PDCP sublayer 245. PDCP sublayer 245 provides radio bearers to SDAP sublayer 250 and / or RRC layer 255. SDAP sublayer 250 provides QoS flows to the core network (e.g., 5GC). RRC layer 255 provides the addition, modification, and release of carrier aggregation and / or dual connectivity. RRC layer 255 also manages the establishment, configuration, maintenance, and release of signaling radio bearers (“SRBs”) and data radio bearers (“DRBs”).

[0072] NAS layer 260 is located between UE 205 and 5GC 515. NAS messages are transparently transmitted through the RAN. NAS layer 260 is used to manage the establishment of communication sessions and to maintain continuous communication with UE 205 when UE 205 moves between different cells in the RAN. Conversely, AS layer is located between UE 205 and the RAN that carries information through the radio portion of the network.

[0073] Figure 3 A scenario 300 for directed LBT according to embodiments of the present disclosure is depicted. Scenario 300 may involve UE 205, RAN node 210 with which UE 205 expects to transmit UL transmissions, and access point (“AP”) 305 representing a potential user with the same communication frequency as UE 205 and RAN node 210. UE 205 may be an implementation of remote unit 105 and RAN node 210 may be an implementation of base station unit 121. UE 205 has generated a UL TB for transmission to RAN node 210, and therefore performs the LBT procedure for the Tx panel / beam configuration set corresponding to the UL transmission.

[0074] As depicted, UE 205 performs an LBT procedure for at least beam #1 at time 't1', i.e., prepares for UL transmission using CG resources. Note that the LBT procedure determines whether RAN node 210, AP 305, or another device is using the channel (i.e., radio frequency) that UE 205 will use for UL transmission. Here, it is assumed that beam #1 is the sensing beam corresponding to the first UE panel and that UE 205 supports multiple panels. As depicted, LBT is successful for sensing beam #1. In cases where the LBT procedure includes evaluating multiple beams, it is assumed here that the Tx beam and / or UE panel corresponding to sensing beam #1 is selected.

[0075] UE 205 performs a UL transmission on CG resources using Tx beam #1 and starts a UL failure timer. However, an uplink transmission failure occurs, so RAN node 210 either does not receive the UL transmission or cannot decode it. Because the UE does not receive a HARQ-ACK from RAN node 210 before the failure timer expires, the UE determines that the UL transmission has failed. As used herein, “HARQ-ACK” can collectively represent a positive acknowledgment (“ACK”) and a negative acknowledgment (“NACK”). ACK means that TB was received correctly, while NACK (or NAK) means that TB was received incorrectly.

[0076] In response to a determination that UL Tx has failed for Tx beam #1, UE 205 switches to the second sensing beam / UE panel and performs LBT for at least beam #2 at time 't2', i.e., prepares for UL transmission at a second timing using CG resources. Here, it is assumed that LBT is successful for sensing panel / beam #2. Therefore, UE 205 performs UL transmission on the corresponding Tx panel / beam #2. However, if LBT fails for Rx panel / beam #2, UE 205 continues to perform the LBT procedure for the configuration set of Tx panels / beams until LBT succeeds or until LBT fails for all configured panels / beams.

[0077] Figure 4 An LBT process 400 for a radio frame 405 for unlicensed communication according to an embodiment of this disclosure is depicted. When the communication channel is a wide-bandwidth unlicensed carrier 410 (e.g., several hundred megahertz), the CCA / LBT process relies on detecting the energy levels on multiple subbands 415 of the communication channel, such as... Figure 4 As shown in the diagram. LBT parameters (such as type / duration, idle channel assessment parameters, etc.) are configured in UE 205 by RAN node 210. In one embodiment, the LBT procedure is performed at PHY layer 230.

[0078] Figure 4 The frame structure of radio frame 405 for unlicensed communication between UE 205 and RAN node 210 is also depicted. Radio frame 405 can be divided into subframes (indicated by subframe boundary 420) and can be further divided into time slots (indicated by time slot boundary 425). Radio frame 405 uses a flexible arrangement in which uplink and downlink operation are on the same frequency channel but are separated in time. However, subframes are not configured as downlink subframes or uplink subframes, and a particular subframe can be used by either UE 205 or RAN node 210. As previously discussed, LBT is performed before transmission. In the event of a misalignment between LBT and time slot boundary 425, a reservation signal 430 can be transmitted to reserve the channel until the time slot boundary is reached and data transmission begins.

[0079] As discussed above, according to the first solution, UE 205 is configured with the same CG resources for different panels / beams. When UE 205 performs CCA / LBT in one of the configured sensing beams and transmits TB in one of the configured Tx beams after the success of LBT, UE 205 initiates (i.e., starts) a timer. If UE 205 does not receive HARQ feedback within a specified time (e.g., when the timer expires), UE 205 detects (i.e., declares) a UL Tx failure. In one embodiment, this timer is a CG retransmission timer. In another embodiment, this timer is a new timer introduced to detect UL Tx failure.

[0080] Note that the CG retransmission timer is implicitly associated with decoding failures at the RAN node due to interference during transmission at the RAN node, channel conditions, or short LBT failures. However, in another implementation of the first solution, a new timer—distinct from the CG retransmission timer—is introduced, which can be an LBT / CCA-specific timer that can be associated with a certain channel access priority class. Regardless of the implementation, the timer is started after a TB transmission in the uplink and stops after receiving the corresponding HARQ feedback. Additionally, the expiration of the timer triggers autonomous panel / beam switching, as discussed below.

[0081] As used herein, UE autonomous behavior refers to an action initiated by the UE, whereby the UE responds to an internal trigger and performs the action without waiting for (and receiving) instructions from the network (e.g., RAN and / or CN). Therefore, UE205 autonomously switching to a different panel / beam refers to a handover initiated by a UE to a different panel / beam, whereby UE 205 performs the handover without receiving instructions from the network to switch panels / beams.

[0082] Upon detecting (i.e., determining) a UL Tx failure, UE 205 is allowed to autonomously switch to a different panel / beam to perform CCA / LBT for (re)transmission of the same TB within the same CG resource. In one embodiment, UE 205 autonomously switches to a different sensing beam—from a configured sensing beam—to perform CCA / LBT. In another embodiment, UE 205 autonomously switches to a different Tx beam—from a configured Tx beam—for retransmission of the TB.

[0083] In an embodiment of the first solution, RAN node 210 (e.g., gNB) uses the same spatial filter used for CG transmission to report HARQ feedback. Aperiodic uplink control information (“A-UCI”) indicates the panel / beam ID used by UE 205 in the CG resources. Here, UE 205 can select a first panel for LBT-UL transmission from the configured set of panels / beams based on the DL channel signal strength, where the selection can be based on measurements of SSB, CSI-RS, etc.

[0084] According to the second solution, UE 205 is configured with different CG resources for different panels / beams. As in the first solution, UE 205 performs CCA / LBT for each TX panel / beam and transmits TB after a successful LBT. If UE 205 does not receive HARQ feedback within a specified time period (i.e., when the CG retransmission timer discussed above or the new LBT / CCA-specific timer expires), UE 205 declares UL Tx failure.

[0085] Secondly, RAN node 210 uses the same spatial filter for CG transmission to report HARQ feedback, and the A-UCI indicates the panel / beam ID used by the UE in the CG resource. Upon detecting / claiming a UL Tx failure, UE 205 can autonomously switch to a different panel / beam to perform CCA / LBT to transmit the same TB in different CG resources. However, in the second solution, each CG resource is associated with the UE 205's TX panel / beam.

[0086] In one embodiment of the second solution, UE 205 starts a CG retransmission timer after the TB transmission and declares UL Tx failure when the CG retransmission timer expires. As mentioned above, the CG retransmission timer can be implicitly associated with decoding failure at the RAN node due to interference or channel conditions or short LBT failure during transmission at the RAN node.

[0087] In another embodiment of the second solution, UE 205 starts a new timer—different from the CG retransmission timer—after the transmission of the TB, and declares UL Tx failure upon the expiration of the CG retransmission timer. As mentioned above, the new timer can be an LBT / CCA-specific timer that can be associated with a certain channel access priority class. Alternatively, the new timer can be a CG-specific timer. Regardless of the implementation, the timer is started after the transmission of the TB in the uplink and stops upon receiving the corresponding HARQ feedback. The expiration of the timer triggers autonomous panel / beam switching.

[0088] According to the second solution, UE 205 can select a first panel from the panel / beam set for LBT-UL transmission based on the DL channel signal strength. Here, the selection can be based on measurements of SSB, CSI-RS, etc. UE 205 then selects a CG resource with the same TBS for retransmission. Alternatively, UE 205 can first select a CG resource with the same TBS and then select a UE panel for UL transmission. UE 205 can choose to use the same HARQ process for transmission in different CG resources, as long as the TBS is the same.

[0089] According to the third solution, UE 205 can be configured with the same CG resources for multiple panels / beams. Furthermore, UE 205 performs LBT for multiple panels / beams, where only one panel / beam is selected for UL transmission.

[0090] UE 205 performs a first LBT / CCA using one panel / beam and transmits a TB after a successful LBT / CCA procedure. Then, if no HARQ-ACK is received, after the CG retransmission timer (or the new LBT / CCA-specific timer introduced above) expires, UE 205 performs a second LBT on the same CG resource using another set of panels / beams. In some embodiments, multiple panels / beams can be used simultaneously on the same CG resource to perform the second LBT. After a successful LBT / CCA procedure, UE 205 performs UL transmission on the panel / beam based on LBT-ED, i.e., where ED is compared for different panels / beams and the panel / beam is selected based on the minimum ED value.

[0091] In another implementation, a first LBT can be performed on one panel / beam, and if it fails, a second LBT can be performed simultaneously on two panels / beams from the configuration set of panels / beams, and if that fails, a third LBT can then be performed simultaneously on three panels / beams from the configuration set of panels / beams, and so on.

[0092] According to the fourth solution, UE 205 can be configured with different CG resources for different panels / beams. UE 205 performs LBT on multiple panels / beams. In addition, the UE can select multiple panels / beams for UL transmission on different CG resources.

[0093] UE 205 can simultaneously perform LBT / CCA on a set of panel / beam configurations and repeat the same TB across different CG resources after a successful LBT. Here, CG resources are assigned to each TX panel / beam individually. The RAN node provides HARQ feedback in the same spatial filter used to receive the CG resources. UE 205 stops retransmission of the initial transmission in all CG resources and also flushes the HARQ buffers of all HARQ processes after it receives at least one HARQ-ACK feedback. In one implementation, HARQ feedback can be transmitted from the RAN node from one or more panels after a short LBT.

[0094] The strategies described above for handling directional LBT and UL failures can be extended to other channels used in wireless communication systems.

[0095] According to the fifth solution, when LBT fails for the first panel / beam, UE 205 can use another panel / beam to perform RACH preamble transmission. When UE 205 fails to transmit the RACH preamble from the panel associated with the highest DL signal reception quality of the SSB due to LBT failure, UE 205 can then autonomously switch to another panel / beam for RACH preamble transmission. Here, UE 205 can select the panel / beam selected based on the next best DL signal reception quality of the SSB. In some embodiments, UE 205 does not increment the preamble transmission counter and preamble ramp counter when autonomously switching to another panel / beam for RACH preamble transmission.

[0096] In an alternative implementation, multiple panels / beams can be used to perform CCA / LBT simultaneously, and only one panel / beam can be used to perform RACH preamble transmission, wherein the panel / beam is selected for RACH preamble transmission based on DL signal strength and reception quality. In another implementation, after successful CCA / LBT, RACH preamble transmission + MsgA is performed on multiple panels, wherein MsgA (i.e., the first message of the two-step random access procedure) contains the UE identity and panel ID / beam ID, and RAN node 210 can transmit only one RAR based on the reception quality of the RACH preamble.

[0097] According to the sixth solution, UE 205 performs CCA for omnidirectional transmission and short LBT for directional transmission. Here, UE 205 can perform a "first LBT" in an omnidirectional manner for, for example, a counter-based access with exponential backoff, such as CAT-4 LBT, and it may successfully or unsuccessfully acquire a channel or wish to switch to another panel / beam for directional transmission. UE 205 can then perform a "second LBT" using a CAT-2 LBT type, which uses a shorter LBT such as energy sensing for 25μs or 16μs. The sixth solution is applicable to data channels, control channels, and RACH / SRS transmissions. In another embodiment of the sixth solution, multiple panels / beams can also be used to perform the second LBT simultaneously.

[0098] According to the seventh solution, the Group Common Downlink Control Information (“DCI”) from RAN node 210 (e.g., gNB) indicates that multiple panels / beams have been successfully executed for DL-initiated COT sharing, whereby CCA / LBT is successful. Here, RAN node 210 may indicate multiple panels / beams in the DCI via a “from panel / beam ID” element, a “CSI-RS configuration” element, a “SSB configuration” element, a Transmission Configuration Indicator (“TCI”) status, or a QCL-TypeD, whereby CCA / LBT is successfully executed for DL-initiated COT sharing. In this case, the COT sharing field in the DCI contains multiple COT sharing indicators, each represented by a TCI status or a QCL-TypeD relationship with one or more semi-statically configured transmission beams. After receiving this DCI information containing the DL COT sharing indicators, UE 205 can then choose to execute CCA / LBT for UL transmission using a shorter LBT (e.g., CAT-2 LBT type) in any one of the indicated beams / panels or all simultaneously. One or more beams / panels may be used to perform UL transmissions, which may be further scheduled in the configured CG resources via DCI or via autonomous uplink, as illustrated in the previous embodiments.

[0099] Regarding the quasi-co-location (“QCL”) assumption, in some embodiments, UE 205 is configured with a list of up to M TCI state configurations within the higher-layer parameter PDSCH-Config to decode the PDSCH based on the detected PDSCH having DCI intended for use by the UE and a given serving cell, where the value of M depends on the UE capability maxNumberConfiguredTCIstatesPerCC.

[0100] Each TCI state configuration contains parameters for configuring the QCL relationship between one or two downlink reference signals and one or more CSI-RS ports of the PDSCH DM-RS port, PDCCH DM-RS port, or CSI-RS resource(s). The QCL relationship is configured by the higher-layer parameter 'qcl-Type1' for the first DL RS and the higher-layer parameter 'qcl-Type2' (if configured) for the second DL RS. For the two DL RSs, the QCL types are different, regardless of whether the reference is to the same DL RS or different DL RSs. The quasi-co-address type corresponding to each DL RS is given by the higher-layer parameter qcl-Type in QCL-Info and can take one of the following values:

[0101] 'QCL-TypeA': {Doppler frequency shift, Doppler spread, average delay, delay spread}

[0102] 'QCL-TypeB': {Doppler frequency shift, Doppler spread}

[0103] 'QCL-TypeC': {Doppler shift, average delay}

[0104] 'QCL-TypeD': {space Rx parameter}

[0105] In some embodiments, UE 205 receives an activation command, either in a single CC / DL BWP or in a group of CC / DL BWPs, for mapping up to eight TCI states to code points in the DCI field 'Transmission Configuration Indication'. When activating a set of TCI state IDs for a group of CC / DL BWPs, the same set of TCI state IDs is applied to all DL BWPs in the indicated CC, provided that the applicable list of component carriers (“CCs”) is determined by the CCs indicated in the activation command.

[0106] When UE 205 supports two TCI states in the code point of the DCI field 'Transmission Configuration Indicator', UE 205 can receive an activation command, which is then used to map up to eight combinations of one or two TCI states to the code point of the DCI field 'Transmission Configuration Indicator'.

[0107] When UE 205 transmits a PUCCH with HARQ-ACK information in slot n corresponding to the PDSCH carrying the activation command, the mapping indicated between the TCI state and the code point of the DCI field 'Transmission Configuration Indication' should be applied starting from the first slot, in the slot... Subsequently, μ is the SCS configuration for PUCCH. If the parameter tci-PresentInDCI is set to "enabled" or tci-PresentInDCI-ForFormat1_2 is configured for the control resource set ("CORESET") for scheduling PDSCH, and the time offset between the reception of DL DCI and the corresponding PDSCH is equal to or greater than timeDurationForQCL (if applicable), then after UE 205 receives the initial higher-layer configuration of the TCI state and before receiving the activation command, UE 205 may assume that the DM-RS port of the serving cell's PDSCH is quasi-co-located with the SS / PBCH block determined during the initial access process relative to 'QCL-TypeA' and, where applicable, also relative to 'QCL-TypeD'.

[0108] If UE 205 has a higher-layer parameter tci-PresentInDCI configured as 'enabled' for the CORESET that schedules PDSCH, then UE 205 assumes that the TCI field exists in DCI format 1_1 of the PDCCH transmitted on the CORESET. If UE has a higher-layer parameter tci-PresentInDCI-ForFormat1_2 configured for the CORESET that schedules PDSCH, then UE assumes that the TCI field with the DCI field size indicated by tci-PresentInDCI-ForFormat1_2 exists in DCI format 1_2 of the PDCCH transmitted on the CORESET. If the PDSCH is scheduled by a DCI format that does not have a TCI field, and the time offset between the reception of the DL DCI and the corresponding PDSCH is equal to or greater than the threshold timeDurationForQCL (if applicable), where the threshold is based on the reported UE capability for determining the quasi-co-addressable PDSCH antenna port, then UE 205 assumes that the TCI state or QCL assumption of the PDSCH is the same as the TCI state or QCL assumption for the CORESET application used for PDCCH transmission.

[0109] If the PDSCH is scheduled by a DCI format with a TCI field present, and the TCI field in the DCI of the scheduled component carrier points to an activated TCI state in the scheduled component carrier or DL ​​BWP, UE 205 will use the TCI state based on the value of the 'Transmission Configuration Indication' field in the detected PDCCH with a DCI used to determine the quasi-co-addressable PDSCH antenna port. UE 205 may assume that if the time offset between the reception of the DL DCI and the corresponding PDSCH is equal to or greater than the threshold timeDurationForQCL, where the threshold is based on the reported UE capability, then the DM-RS port of the serving cell's PDSCH is quasi-co-addressable with respect to one or more QCL type parameters given by the indicated TCI state and is in TCI state.

[0110] When UE 205 is configured with a single-slot PDSCH, the indicated TCI state should be based on the active TCI state in the slot with the scheduled PDSCH. When UE 205 is configured with a multi-slot PDSCH, the indicated TCI state should be based on the active TCI state in the first slot with the scheduled PDSCH, and UE 205 expects the active TCI state to be the same across the slots with the scheduled PDSCH.

[0111] Regardless of the configuration of tci-PresentInDCI and tci-PresentInDCI-ForFormat1_2 in RRC connection mode, if all TCI code points are mapped to a single TCI state and the offset between the received DL DCI and the corresponding PDSCH is less than the threshold timeDurationForQCL, UE 205 may assume that the DM-RS port of the serving cell's PDSCH is quasi-co-located with (one or more) RS quasi-co-located in the latest time slot relative to (one or more) QCL parameters for the PDCCH quasi-co-location indication of the CORESET associated with the monitoring search space having the lowest controlResourceSetId, in which one or more CORESETs within the active BWP of the serving cell are monitored by UE 205. In this case, if the 'QCL-TypeD' of the PDSCH DM-RS is different from the 'QCL-TypeD' of the PDCCH DM-RS that overlaps with it in at least one symbol, UE 205 is expected to prioritize the reception of the PDCCH associated with that CORESET. This also applies to in-band CA (when PDSCH and CORESET are in different component carriers).

[0112] If none of the TCI states configured for the serving cell of the scheduled PDSCH contain 'QCL-TypeD', then UE 205 will obtain other QCL assumptions from the TCI states indicated for its scheduled PDSCH, regardless of the time offset between the received DL DCI and the corresponding PDSCH. If UE 205 is configured by the higher-layer parameter PDCCH-Config, which contains two different values ​​of CORESETPoolIndex in the ControlResourceSet, then for both cases—when tci-PresentInDCI is set to 'enabled' and when tci-PresentInDCI is not configured in RRC connection mode—if the offset between the received DL DCI and the corresponding PDSCH is less than the threshold timeDurationForQCL, then UE 205 205 may assume that the DM-RS port of the PDSCH associated with the value of the CORESETPoolIndex of the serving cell is monitored by UE 205 in the latest time slot relative to one or more QCL parameters and RS quasi-co-address of the PDCCH of the CORESET associated with the monitoring search space that has the lowest CORESET-ID in the CORESET (which is configured with the same CORESETPoolIndex value as the PDCCH that schedules the PDSCH).

[0113] If the offset between the received DL DCI and the corresponding PDSCH is less than the threshold timeDurationForQCL and at least one configured TCI state of the serving cell for the scheduled PDSCH contains 'QCL-TypeD', and at least one TCI code point indicates two TCI states, then UE 205 may assume that the DM-RS port of the serving cell's PDSCH is quasi-co-located with (one or more) RS quasi-co-located relative to the QCL parameter(s) associated with the TCI state corresponding to the lowest code point among the TCI code points containing two different TCI states.

[0114] For periodic CSI-RS resources in a non-zero power CSI-RS resource set (“NZP-CSI-RS-ResourceSet”) configured with higher-level parameter trs-Info, UE 205 will expect the TCI state to indicate one or more of the following quasi-co-address types:

[0115] 'QCL-TypeC' with an SS / PBCH block, and, where applicable, 'QCL-TypeD' with the same SS / PBCH block, or

[0116] 'QCL-TypeC' with an SS / PBCH block, and 'QCL-TypeD', where applicable, with a CSI-RS resource in an NZP-CSI-RS-ResourceSet configured with the higher-level parameter repetition, or

[0117] For non-periodic CSI-RS resources in the NZP-CSI-RS-ResourceSet configured with higher-level parameter trs-Info, UE 205 will expect the TCI state to indicate 'QCL-TypeA' with periodic CSI-RS resources in the NZP-CSI-RS-ResourceSet configured with higher-level parameter trs-Info, and, where applicable, 'QCL-TypeD' with the same periodic CSI-RS resources.

[0118] For CSI-RS resources in an NZP-CSI-RS-ResourceSet that are configured with no higher-level parameter trs-Info and no higher-level parameter repetition, UE 205 will expect the TCI status to indicate one or more of the following quasi-co-address types:

[0119] 'QCL-TypeA' has CSI-RS resources in an NZP-CSI-RS-ResourceSet configured with the higher-level parameter trs-Info, and, where applicable, 'QCL-TypeD' has the same CSI-RS resources, or

[0120] 'QCL-TypeA' has CSI-RS resources in an NZP-CSI-RS-ResourceSet configured with the higher-level parameter trs-Info, and 'QCL-TypeD', where applicable, has an SS / PBCH block, or

[0121] 'QCL-TypeA' has CSI-RS resources in an NZP-CSI-RS-ResourceSet configured with the higher-level parameter trs-Info, and, where applicable, 'QCL-TypeD' has CSI-RS resources in an NZP-CSI-RS-ResourceSet configured with the higher-level parameter repetition, or

[0122] When 'QCL-TypeD' is not applicable, it has 'QCL-TypeB', which has CSI-RS resources in the NZP-CSI-RS-ResourceSet configured with the higher-level parameter trs-Info.

[0123] For CSI-RS resources in an NZP-CSI-RS-ResourceSet configured with the higher-level parameter repetition, UE 205 will expect the TCI status to indicate one or more of the following quasi-co-location types:

[0124] 'QCL-TypeA' has CSI-RS resources in an NZP-CSI-RS-ResourceSet configured with the higher-level parameter trs-Info, and, where applicable, 'QCL-TypeD' has the same CSI-RS resources, or

[0125] 'QCL-TypeA' has CSI-RS resources in an NZP-CSI-RS-ResourceSet configured with the higher-level parameter trs-Info, and, where applicable, 'QCL-TypeD' has CSI-RS resources in an NZP-CSI-RS-ResourceSet configured with the higher-level parameter repetition, or

[0126] 'QCL-TypeC' has an SS / PBCH block, and 'QCL-TypeD', where applicable, has the same SS / PBCH block.

[0127] For DM-RS of PDCCH, UE 205 expects the TCI status to indicate one or more of the following quasi-co-location types:

[0128] 'QCL-TypeA' has CSI-RS resources in an NZP-CSI-RS-ResourceSet configured with the higher-level parameter trs-Info, and, where applicable, 'QCL-TypeD' has the same CSI-RS resources, or

[0129] 'QCL-TypeA' has CSI-RS resources in an NZP-CSI-RS-ResourceSet configured with the higher-level parameter trs-Info, and 'QCL-TypeD', where applicable, has CSI-RS resources in an NZP-CSI-RS-ResourceSet configured with the higher-level parameter repetition, or

[0130] 'QCL-TypeA' has a CSI-RS resource in an NZP-CSI-RS-ResourceSet that has no higher-level parameter trs-Info and no higher-level parameter repetition, and 'QCL-TypeD', where applicable, has the same CSI-RS resource.

[0131] For DM-RS of PDSCH, UE 205 will expect the TCI status to indicate one or more of the following quasi-co-location types:

[0132] 'QCL-TypeA' has CSI-RS resources in an NZP-CSI-RS-ResourceSet configured with the higher-level parameter trs-Info, and 'QCL-TypeD', where applicable, has the same CSI-RS resources, or

[0133] 'QCL-TypeA' has CSI-RS resources in an NZP-CSI-RS-ResourceSet configured with the higher-level parameter trs-Info, and, where applicable, 'QCL-TypeD' has CSI-RS resources in an NZP-CSI-RS-ResourceSet configured with the higher-level parameter repetition, or

[0134] 'QCL-TypeA' has a CSI-RS resource in an NZP-CSI-RS-ResourceSet that has no higher-level parameter trs-Info and no higher-level parameter repetition, and 'QCL-TypeD', where applicable, has the same CSI-RS resource.

[0135] Figure 5 User equipment device 500, which can be used for beam switching after a LBT process, is depicted according to embodiments of the present disclosure. In various embodiments, user equipment device 500 is used to implement one or more of the solutions described above. User equipment device 500 may be an embodiment of the remote unit 105 and / or UE 205 described above. Furthermore, user equipment device 500 may include processor 505, memory 510, input device 515, output device 520, and transceiver 525.

[0136] In some embodiments, input device 515 and output device 520 are combined into a single device, such as a touchscreen. In some embodiments, user equipment device 500 may not include any input device 515 and / or output device 520. In various embodiments, user equipment device 500 may include one or more of the following: processor 505, memory 510, and transceiver 525, and may not include input device 515 and / or output device 520.

[0137] As depicted, transceiver 525 includes at least one transmitter 530 and at least one receiver 535. In some embodiments, transceiver 525 communicates with one or more cells (or radio coverage areas) supported by one or more base station units 121. In various embodiments, transceiver 525 may operate on unlicensed spectrum. Furthermore, transceiver 525 may include multiple UE panels supporting one or more beams. Additionally, transceiver 525 may support at least one network interface 540 and / or application interface 545. One or more application interfaces 545 may support one or more APIs. One or more network interfaces 540 may support 3GPP reference points such as Uu, N1, PC5, etc. Other network interfaces 540 may be supported, as will be understood by those skilled in the art.

[0138] In one embodiment, processor 505 may include any known controller capable of executing computer-readable instructions and / or performing logical operations. For example, processor 505 may be a microcontroller, microprocessor, central processing unit (“CPU”), graphics processing unit (“GPU”), auxiliary processing unit, field-programmable gate array (“FPGA”), or similar programmable controller. In some embodiments, processor 505 executes instructions stored in memory 510 to perform the methods and routines described herein. Processor 505 is communicatively coupled to memory 510, input device 515, output device 520, and transceiver 525. In some embodiments, processor 505 may include an application processor (also referred to as a “main processor”) that manages application domain and operating system (“OS”) functions, and a baseband processor (also referred to as a “baseband radio processor”) that manages radio functions.

[0139] In various embodiments, processor 505 controls user equipment device 500 to implement the UE behavior described above. For example, processor 505 may perform an LBT procedure at a first UE panel prior to a first timing of the CG resource. Processor 505, in response to a successful LBT during the first timing, performs a first TB UL transmission using the first UE panel. In some embodiments, the UL transmission during the first timing is accompanied by uplink control information (“UCI”) that identifies the UE panel used for transmission on the CG resource. Note that while user equipment device is described in terms of performing an LBT procedure for a “set of UE panels,” in other embodiments, LBT may be performed for a “set of beams.” As used herein, the term “panel / beam” (or similar notation) indicates that this description applies to UE panels and / or beams.

[0140] In some embodiments, performing the LBT process includes performing an idle channel assessment for a plurality of sensed UE panels. In such embodiments, performing the first TB UL transmission further includes transmitting the first TB using at least one additional TX UE panel from the plurality of sensed UE panels that have successfully performed the LBT, wherein each TX UE panel is associated with a different CG resource.

[0141] In some embodiments, performing a first TB of UL transmission during a first timing period includes selecting a single TX UE panel from a plurality of TX UE panels and using the selected TX UE panel to transmit the first TB. In some embodiments, a single TX UE panel from a plurality of TX UE panels is selected based on the lowest energy detection value from an idle channel assessment of the sensing UE panel. In such embodiments, a QC type-D relationship exists between the plurality of sensing UE panels and the plurality of TX UE panels.

[0142] Processor 505 initiates a timer in response to a UL transmission. In some embodiments, the timer includes a CG retransmission timer or a panel failure timer different from the CG retransmission timer. In some embodiments, the panel failure timer is associated with a channel access priority class. In some embodiments, the value of the timer corresponds to the channel access priority class used for UL transmission.

[0143] In some embodiments, processor 505 determines that a UL transmission has failed due to the lack of HARQ-ACK feedback received within the duration of the timer. In other embodiments, processor 505 receives at least one HARQ-ACK feedback for the first TB and terminates the timer in response to the HARQ-ACK feedback. Here, processor 505 further flushes the HARQ buffer associated with the transmission of the first TB in response to receiving HARQ-ACK feedback for the first TB. In some embodiments, processor further terminates the retransmission of the first TB and flushes all HARQ buffers associated with the transmission of the first TB in response to receiving at least one HARQ-ACK feedback.

[0144] Processor 505 switches to a second UE panel for subsequent UL transmissions for the first TB in response to determining that a UL transmission failure has occurred. In some embodiments, the UL transmission during the first timing is associated with a first HARQ process. In such embodiments, performing the UL transmission during a second timing and using the second UE panel includes reusing the first HARQ process.

[0145] In some embodiments, the UE is configured with multiple sensing UE panels. In such embodiments, a first sensing UE panel is used to perform the LBT process, wherein switching to a second UE panel includes switching from the first sensing UE panel to the second sensing UE panel. In some embodiments, the UE is configured with multiple TX UE panels. In such embodiments, a first TB UL transmission is performed for the first TX UE panel, wherein switching to a second UE panel includes switching from the first TX UE panel to the second TX UE panel.

[0146] In some embodiments, the second UE panel is associated with the same CG resource as the first UE panel. In such embodiments, subsequent UL transmissions are performed using a time-frequency resource that is the same as the first timing of the CG resource. In other embodiments, each TX UE panel is associated with a different CG resource. In such embodiments, subsequent UL transmissions are performed using a time-frequency resource that is different from the first timing of the CG resource. In some embodiments, performing subsequent UL transmissions includes selecting a CG resource with the same TB size as the first timing of the CG resource.

[0147] In various embodiments, user equipment device 500 supports time-domain multiplexing (“TDM”) of DL / UL transmissions in different panels / beams within the same COT. Here, processor 505 may perform LBT (i.e., directional or omnidirectional LBT) at the start of the COT. In some embodiments, processor 505 performs additional directional LBT with sensing panels / beams covering the next TX panel / beam for each panel / beam switching in the middle of the COT, as described herein. Note that when performing additional directional LBT, the first LBT may cover all TDM panels / beams or may cover only the first TX panel / beam. In other embodiments, processor 505 does not perform additional LBT before each panel / beam switching in the middle of the COT, wherein one or more sensing panels / beams(s) for the (first) LBT process cover all TDM panels / beams.

[0148] In various embodiments, processor 505 uses omnidirectional sensing to perform a first LBT process to obtain a first COT. Via transceiver 525, processor 505 performs a first UL transmission of a first TB during the first COT and using a first TX panel / beam in response to a successful LBT. Here, the first UL transmission uses a first portion of the first COT (i.e., not the entire first COT). Processor 505 performs a directional LBT process for a second UE panel to obtain the remaining portion of the first COT.

[0149] In some embodiments, processor 505 performs a first LBT procedure to obtain a first COT (i.e., an LBT with random backoff and a variable-size contention window) using a Category 4 (“Cat-4”) LBT procedure. In such embodiments, processor 505 also performs a directed LBT procedure using a Category 2 (“Cat-2”) LBT procedure (i.e., an LBT without random backoff). In some embodiments, performing the first LBT procedure includes concurrently performing the directed LBT procedure for all configured UE panels.

[0150] In one embodiment, memory 510 is a computer-readable storage medium. In some embodiments, memory 510 includes volatile computer storage media. For example, memory 510 may include RAM, including dynamic RAM (“DRAM”), synchronous dynamic RAM (“SDRAM”), and / or static RAM (“SRAM”). In some embodiments, memory 510 includes non-volatile computer storage media. For example, memory 510 may include a hard disk drive, flash memory, or any other suitable non-volatile computer storage device. In some embodiments, memory 510 includes both volatile and non-volatile computer storage media.

[0151] In some embodiments, memory 510 stores data related to beam switching after the LBT process. For example, memory 510 may store various parameters, panel / beam configurations, resource assignments, strategies, etc., as described above. In some embodiments, memory 510 also stores program code and related data, such as an operating system or other controller algorithms operating on device 500.

[0152] In one embodiment, input device 515 may include any known computer input device, including a touch panel, button, keyboard, stylus, microphone, etc. In some embodiments, input device 515 may be integrated with output device 520, for example, as a touchscreen or similar touch-sensitive display. In some embodiments, input device 515 includes a touchscreen, allowing text to be entered using a virtual keyboard displayed on the touchscreen and / or by handwriting on the touchscreen. In some embodiments, input device 515 includes two or more different devices, such as a keyboard and a touch panel.

[0153] In one embodiment, output device 520 is designed to output visual, auditory, and / or tactile signals. In some embodiments, output device 520 includes an electronically controllable display or display device capable of outputting visual data to a user. For example, output device 520 may include, but is not limited to, LCD displays, LED displays, OLED displays, projectors, or similar display devices capable of outputting images, text, etc., to a user. As another non-limiting example, output device 520 may include a wearable display, such as a smartwatch, smart glasses, head-up display, etc., that is separate from but communicatively coupled to the rest of user equipment device 500. Furthermore, output device 520 may be a component of a smartphone, personal digital assistant, television, desktop computer, laptop computer, personal computer, vehicle dashboard, etc.

[0154] In some embodiments, output device 520 includes one or more speakers for generating sound. For example, output device 520 may generate an auditory alarm or notification (e.g., a beep or ringtone). In some embodiments, output device 520 includes one or more haptic devices for generating vibration, motion, or other haptic feedback. In some embodiments, all or part of output device 520 may be integrated with input device 515. For example, input device 515 and output device 520 may form a touchscreen or similar touch-sensitive display. In other embodiments, output device 520 may be located near input device 515.

[0155] Transceiver 525 communicates with one or more network functions of a mobile communication network via one or more access networks. Transceiver 525 operates under the control of processor 505 to transmit and receive messages, data, and other signals. For example, processor 505 may selectively activate transceiver 525 (or a portion thereof) at specific times to send and receive messages.

[0156] Transceiver 525 includes at least a transmitter 530 and at least one receiver 535. One or more transmitters 530 can be used to provide UL communication signals to base station unit 121, such as UL transmissions described herein. Similarly, as described herein, one or more receivers 535 can be used to receive DL communication signals from base station unit 121. Although only one transmitter 530 and one receiver 535 are illustrated, user equipment device 500 can have any suitable number of transmitters 530 and receivers 535. Furthermore, the transmitter(s) 530 and receiver(s) 535 can be of any suitable type. In one embodiment, transceiver 525 includes a first transmitter / receiver pair for communicating with a mobile communication network on licensed radio spectrum and a second transmitter / receiver pair for communicating with a mobile communication network on unlicensed radio spectrum.

[0157] In some embodiments, a first transmitter / receiver pair for communicating with a mobile communication network on licensed radio spectrum and a second transmitter / receiver pair for communicating with a mobile communication network on unlicensed radio spectrum may be combined into a single transceiver unit, such as a single chip performing functions for both licensed and unlicensed radio spectrum. In some embodiments, the first transmitter / receiver pair and the second transmitter / receiver pair may share one or more hardware components. For example, certain transceivers 525, transmitters 530, and receivers 535 may be implemented as physically separate components that access shared hardware and / or software resources, such as network interface 540.

[0158] In various embodiments, one or more transmitters 530 and / or one or more receivers 535 may be implemented and / or integrated into a single hardware component, such as a multi-transceiver chip, system-on-a-chip, ASIC, or other type of hardware component. In some embodiments, one or more transmitters 530 and / or one or more receivers 535 may be implemented and / or integrated into a multi-chip module. In some embodiments, other components such as network interface 540 or other hardware components / circuitets may be integrated with any number of transmitters 530 and / or receivers 535 into a single chip. In such embodiments, transmitters 530 and receivers 535 may be logically configured as a transceiver 525 using a more common control signal or as modular transmitters 530 and receivers 535 implemented in the same hardware chip or multi-chip module.

[0159] Figure 6 A network device apparatus 600, which can be used for beam switching after an LBT process, is depicted according to embodiments of the present disclosure. In one embodiment, the network device apparatus 600 may be an implementation of a RAN node, such as base station unit 121, RAN node 210, or gNB as described above. Furthermore, the base station network device apparatus 600 may include a processor 605, a memory 610, an input device 615, an output device 620, and a transceiver 625.

[0160] In some embodiments, input device 615 and output device 620 are combined into a single device, such as a touchscreen. In some embodiments, network device device 600 may not include any input device 615 and / or output device 620. In various embodiments, network device device 600 may include one or more of the following: processor 605, memory 610, and transceiver 625, and may not include input device 615 and / or output device 620.

[0161] As depicted, transceiver 625 includes at least one transmitter 630 and at least one receiver 635. Here, transceiver 625 communicates with one or more remote units 105. Additionally, transceiver 625 may support at least one network interface 640 and / or application interface 645. The application interface(s) 645 may support one or more APIs. The network interface(s) 640 may support 3GPP reference points such as Uu, N1, N2, and N3. Other network interfaces 640 may be supported, as will be understood by those skilled in the art.

[0162] In one embodiment, processor 605 may include any known controller capable of executing computer-readable instructions and / or performing logical operations. For example, processor 605 may be a microcontroller, microprocessor, CPU, GPU, auxiliary processing unit, FPGA, or similar programmable controller. In some embodiments, processor 605 executes instructions stored in memory 610 to perform the methods and routines described herein. Processor 605 is communicatively coupled to memory 610, input device 615, output device 620, and transceiver 625.

[0163] In various embodiments, network device apparatus 600 is a RAN node (e.g., gNB) that transmits UE configuration and receives measurement reports, as described herein. In such embodiments, processor 605 controls network device apparatus 600 to perform the aforementioned actions. When operating as a RAN node, processor 605 may include an application processor (also referred to as the "main processor") that manages application domain and operating system ("OS") functions, and a baseband processor (also referred to as the "baseband radio processor") that manages radio functions.

[0164] In one embodiment, memory 610 is a computer-readable storage medium. In some embodiments, memory 610 includes volatile computer storage media. For example, memory 610 may include RAM, including dynamic RAM (“DRAM”), synchronous dynamic RAM (“SDRAM”), and / or static RAM (“SRAM”). In some embodiments, memory 610 includes non-volatile computer storage media. For example, memory 610 may include a hard disk drive, flash memory, or any other suitable non-volatile computer storage device. In some embodiments, memory 610 includes both volatile and non-volatile computer storage media.

[0165] In some embodiments, memory 610 stores data related to beam switching after the LBT process. For example, memory 610 may store parameters, configurations, resource assignments, strategies, etc., as described above. In some embodiments, memory 610 also stores program code and related data, such as an operating system or other controller algorithms operating on remote unit 65.

[0166] In one embodiment, input device 615 may include any known computer input device, including a touch panel, buttons, keyboard, stylus, microphone, etc. In some embodiments, input device 615 may be integrated with output device 620, for example, as a touchscreen or similar touch-sensitive display. In some embodiments, input device 615 includes a touchscreen, allowing text to be entered using a virtual keyboard displayed on the touchscreen and / or by handwriting on the touchscreen. In some embodiments, input device 615 includes two or more different devices, such as a keyboard and a touch panel.

[0167] In one embodiment, output device 620 is designed to output visual, auditory, and / or tactile signals. In some embodiments, output device 620 includes an electronically controllable display or display device capable of outputting visual data to a user. For example, output device 620 may include, but is not limited to, an LCD display, an LED display, an OLED display, a projector, or similar display devices capable of outputting images, text, etc., to a user. As another non-limiting example, output device 620 may include a wearable display, such as a smartwatch, smart glasses, a head-up display, etc., separate from but communicatively coupled to the rest of network device device 600. Furthermore, output device 620 may be a component of a smartphone, personal digital assistant, television, desktop computer, laptop computer, personal computer, vehicle dashboard, etc.

[0168] In some embodiments, output device 620 includes one or more speakers for generating sound. For example, output device 620 may generate an auditory alarm or notification (e.g., a buzzer or ring). In some embodiments, output device 620 includes one or more haptic devices for generating vibration, motion, or other haptic feedback. In some embodiments, all or part of output device 620 may be integrated with input device 615. For example, input device 615 and output device 620 may form a touchscreen or similar touch-sensitive display. In other embodiments, output device 620 may be located near input device 615.

[0169] Transceiver 625 includes at least a transmitter 630 and at least one receiver 635. As described herein, one or more transmitters 630 can be used to communicate with a UE. Similarly, as described herein, one or more receivers 635 can be used to communicate with network functions in a PLMN and / or RAN. Although only one transmitter 630 and one receiver 635 are illustrated, the network device apparatus 600 can have any suitable number of transmitters 630 and receivers 635. Furthermore, the transmitter(s) 630 and receiver(s) 635 can be of any suitable type.

[0170] Figure 7 An embodiment of a method 700 for beam switching after an LBT process, according to embodiments of the present disclosure, is described. In various embodiments, method 700 is performed by a UE, such as remote unit 105, UE 205, and / or user equipment device 800 as described above. In some embodiments, method 700 is performed by a processor, such as a microcontroller, microprocessor, CPU, GPU, auxiliary processing unit, FPGA, etc.

[0171] Method 700 begins and executes a Listen-Before-Talk ("LBT") procedure 705 before the first timing of the configured licensed ("CG") resource. Method 700 includes, in response to a successful LBT during the first timing, performing an uplink ("UL") transmission of the first transport block ("TB") 710 using the first beam. Method 700 includes starting a timer 715 in response to the UL transmission. Method 700 includes determining a failure of the UL transmission 720 if no HARQ-ACK feedback is received within the duration of the timer. Method 700 includes switching 725 to a second beam for subsequent UL transmissions of the first TB in response to determining a failure of the UL transmission. Method 700 ends.

[0172] Figure 8 An embodiment of a method 800 for beam switching after an LBT process, according to embodiments of the present disclosure, is described. In various embodiments, method 800 is performed by a UE, such as remote unit 105, UE 205, and / or user equipment device 800 as described above. In some embodiments, method 800 is performed by a processor, such as a microcontroller, microprocessor, CPU, GPU, auxiliary processing unit, FPGA, etc.

[0173] Method 800 begins and performs a first LBT process 805 using omnidirectional sensing to obtain a first COT. Method 800 includes performing a first UL transmission 810 using a first TB during the first COT in response to a successful LBT. Here, the first UL transmission uses only a first portion of the first COT. Method 800 includes performing a directional LBT process 815 for a second beam to obtain the remainder of the first COT. Method 800 ends.

[0174] This document discloses a first apparatus for beam switching after an LBT process according to embodiments of the present disclosure. The first apparatus may be implemented by a UE, such as remote unit 105, UE 205, and / or user equipment apparatus 800 as described above. The first apparatus includes a processor and a transceiver operable on unlicensed spectrum, wherein the transceiver supports multiple UE panels. The processor performs the LBT process at a first UE panel prior to a first timing of CG resources. In response to a successful LBT during the first timing and using the first UE panel, the processor performs a UL transmission for a first TB and initiates a timer in response to the UL transmission. In response to not receiving any HARQ-ACK feedback within the duration of the timer, the processor determines that a UL transmission failure has occurred and switches to a second UE panel for subsequent UL transmissions for the first TB in response to determining that a UL transmission failure has occurred. Note that while the first apparatus is described in terms of performing the LBT process and transmission aspects for a set of “UE panels,” in other embodiments, the LBT process and transmission may be performed for a set of “beams.”

[0175] In some embodiments, the UE is configured with multiple sensing UE panels. In such embodiments, a first sensing UE panel is used to perform the LBT process, wherein switching to a second UE panel includes switching from the first sensing UE panel to the second sensing UE panel. In some embodiments, the UE is configured with multiple TX UE panels. In such embodiments, a first TB UL transmission is performed for the first TX UE panel, wherein switching to a second UE panel includes switching from the first TX UE panel to the second TX UE panel.

[0176] In some embodiments, the second UE panel is associated with the same CG resource as the first UE panel. In such embodiments, subsequent UL transmissions are performed using a time-frequency resource that is the same as the first timing of the CG resource. In other embodiments, each TX UE panel is associated with a different CG resource. In such embodiments, subsequent UL transmissions are performed using a time-frequency resource that is different from the first timing of the CG resource. In some embodiments, performing subsequent UL transmissions includes selecting a CG resource with the same TB size as the first timing of the CG resource.

[0177] In some embodiments, the timer includes a CG retransmission timer or a panel failure timer different from the CG retransmission timer. In some embodiments, the panel failure timer is associated with a channel access priority class. In some embodiments, UL transmission during a first timing period is associated with a first HARQ process. In such embodiments, performing UL transmission during a second timing period and using a second UE panel includes reusing the first HARQ process.

[0178] In some embodiments, performing the LBT process includes performing an idle channel assessment for a plurality of sensing UE panels. In such embodiments, performing a first TB UL transmission during a first timing period includes selecting a single TX UE panel from a plurality of TX UE panels and using the selected TX UE panel to transmit the first TB. In some embodiments, a single TX UE panel from a plurality of TX UE panels is selected based on the lowest energy detection value from the idle channel assessment of the sensing UE panels. In such embodiments, a QCLtype-D relationship exists between the plurality of sensing UE panels and the plurality of TX UE panels.

[0179] In some embodiments, performing the LBT process includes performing an idle channel assessment for multiple sensed UE panels. In such embodiments, performing the UL transmission of the first TB further includes transmitting the first TB using at least one additional TX UE panel from the multiple sensed UE panels that has successfully undergone LBT, wherein each TX UE panel is associated with a different CG resource. In some embodiments, the processor further terminates the retransmission of the first TB and flushes all HARQ buffers associated with the transmission of the first TB in response to receiving at least one HARQ-ACK feedback.

[0180] In some embodiments, UL transmission during the first timing period is accompanied by a UCI identifying the UE panel used for transmission on CG resources. In some embodiments, the value of the timer corresponds to the channel access priority class for UL transmission. In some embodiments, the processor further terminates the timer in response to receiving at least one HARQ-ACK feedback for the first TB and refreshes the HARQ buffer associated with the transmission of the first TB in response to receiving HARQ-ACK feedback for the first TB.

[0181] This document discloses a first method for beam switching after an LBT process according to embodiments of the present disclosure. The first method can be performed by a UE, such as the aforementioned remote unit 105, UE 205, and / or user equipment device 800. The first method includes receiving a first message containing a first indication of the UE's access mode, wherein the UE is connected to a non-public radio cell, and transmitting a second message from a RAN node to the user specifying at least one measurement configuration. The first method includes performing an LBT process before a first timing of CG resources and, in response to a successful LBT, performing a UL transmission for a first TB during the first timing and using a first beam. The first method includes starting a timer in response to the UL transmission, determining that a UL transmission failure has occurred in response to no HARQ-ACK feedback being received within the duration of the timer, and switching to a second beam for subsequent UL transmissions for the first TB in response to determining that a UL transmission failure has occurred. Note that while the first method is described in terms of performing the LBT process and transmission for a set of "beams," in other embodiments, the LBT process and transmission can be performed for a set of "UE panels."

[0182] In some embodiments, the UE is configured with multiple sensing beams. In such embodiments, a first sensing beam is used to perform the LBT procedure, wherein switching to a second beam includes switching from the first sensing beam to the second sensing beam. In some embodiments, the UE is configured with multiple TX beams. In such embodiments, a first TB UL transmission is performed for the first TX beam, wherein switching to a second beam includes switching from the first TX beam to the second TX beam.

[0183] In some embodiments, the second beam is associated with the same CG resource as the first beam. In such embodiments, subsequent UL transmissions are performed using the same time-frequency resource as the first timing of the CG resource. In other embodiments, each TX beam is associated with a different CG resource. In such embodiments, subsequent UL transmissions are performed using a different time-frequency resource than the first timing of the CG resource. In some embodiments, performing subsequent UL transmissions includes selecting a CG resource with the same TB size as the first timing of the CG resource.

[0184] In some embodiments, the timer includes a CG retransmission timer or a beam failure timer different from the CG retransmission timer. In some embodiments, the beam failure timer is associated with a channel access priority class. In some embodiments, UL transmission during a first timing period is associated with a first HARQ process. In such embodiments, performing UL transmission during a second timing period and using a second beam includes reusing the first HARQ process.

[0185] In some embodiments, performing the LBT process includes performing an idle channel assessment for a plurality of sensing beams. In such embodiments, performing a first TB UL transmission during a first timing period includes selecting a single TX beam from a plurality of TX beams and using the selected TX beam to transmit the first TB. In some embodiments, a single TX beam from a plurality of TX beams is selected based on the lowest energy detection value from the idle channel assessment of the sensing beams. In such embodiments, a QCL type-D relationship exists between the plurality of sensing beams and the plurality of TX beams.

[0186] In some embodiments, performing the LBT process includes performing an idle channel assessment for multiple sensing beams, wherein performing the UL transmission of the first TB further includes transmitting the first TB using at least one additional TX beam from the multiple sensing beams that has successfully undergone LBT, wherein each TX beam is associated with a different CG resource. In some embodiments, the first method further includes terminating the retransmission of the first TB and flushing all HARQ buffers associated with the transmission of the first TB in response to receiving at least one HARQ-ACK feedback.

[0187] In some embodiments, the UL transmission during the first timing period is accompanied by a UCI identifying the beam used for transmission on the CG resource. In some embodiments, the value of the timer corresponds to the channel access priority class for the UL transmission. In some embodiments, the first method further includes terminating the timer in response to receiving at least one HARQ-ACK feedback for the first TB and refreshing the HARQ buffer associated with the transmission of the first TB in response to receiving HARQ-ACK feedback for the first TB.

[0188] This document discloses a second apparatus for beam switching after an LBT process, according to embodiments of this disclosure. The second apparatus may be implemented by a UE, such as the aforementioned remote unit 105, UE 205, and / or user equipment apparatus 800. The second apparatus includes a processor and a transceiver that can operate on unlicensed spectrum, wherein the transceiver supports multiple UE panels. The processor uses omnidirectional sensing to perform a first LBT process to obtain a first COT and, in response to a successful LBT, performs a first UL transmission of a first TB during the first COT and using the first UE panel. Here, the first UL transmission uses a first portion of the first COT [i.e., not the entire first COT]. The processor performs a directional LBT process for a second UE panel to obtain the remaining portion of the first COT. Note that while the second apparatus is described in terms of performing the LBT process and transmission for a set of “UE panels,” in other embodiments, the LBT process and transmission may be performed for a set of “beams.”

[0189] In some embodiments, performing the first LBT procedure includes obtaining a first COT using a Category 4 (“Cat-4”) LBT procedure, wherein performing the directed LBT procedure includes using a Category 2 (“Cat-2”) LBT procedure. In some embodiments, performing the first LBT procedure includes performing the directed LBT procedure concurrently for all configured UE panels.

[0190] This document discloses a second method for beam switching after an LBT process, according to embodiments of this disclosure. The second method can be performed by a UE, such as the aforementioned remote unit 105, UE 205, and / or user equipment device 800. The second method includes performing a first LBT process using omnidirectional sensing to obtain a first COT and, in response to a successful LBT, performing a first UL transmission of a first TB during the first COT and using a first beam, wherein the first UL transmission uses a first portion of the first COT [i.e., not the entire first COT]. The second method includes performing a directional LBT process for a second beam to obtain the remaining portion of the first COT. Note that while the second method is described in terms of performing the LBT process and transmission for a set of “beams,” in other embodiments, the LBT process and transmission can be performed for a set of “UE panels.”

[0191] In some embodiments, performing the first LBT procedure includes obtaining a first COT using a Category 4 (“Cat-4”) LBT procedure, wherein performing the directional LBT procedure includes using a Category 2 (“Cat-2”) LBT procedure. In some embodiments, performing the first LBT procedure includes performing the directional LBT procedure concurrently for all configured beams.

[0192] The embodiments may be practiced in other specific forms. The described embodiments are to be considered in all respects as illustrative rather than restrictive. Therefore, the scope of the invention is indicated by the appended claims rather than by the foregoing description. All variations within the equivalent meaning and scope of the claims should be covered within their scope.

Claims

1. A method performed by a user equipment, UE, the method comprising: performing a listen before talk, LBT, procedure prior to a first occasion of configured grant, CG, resources; performing an uplink, UL, transmission of a first transport block, TB, during the first occasion and using a first beam in response to a successful LBT; starting a timer in response to the UL transmission; determining a failure of the UL transmission if no HARQ-ACK feedback is received within a duration of the timer; and switching to a second beam for a subsequent UL transmission of the first TB in response to determining a failure of the UL transmission.

2. The method of claim 1, wherein, the UE is configured with a plurality of sensing beams, wherein the LBT procedure is performed using a first sensing beam, and wherein switching to the second beam comprises switching from the first sensing beam to a second sensing beam.

3. The method of claim 1, wherein, the UE is configured with a plurality of transmit, TX, beams, wherein the UL transmission of the first TB is performed for a first TX beam, and wherein switching to the second beam comprises switching from the first TX beam to a second TX beam.

4. The method of claim 1, the second beam is associated with a same CG resource as the first beam, wherein, the subsequent UL transmission is performed using a same time-frequency resource as the first occasion of CG resources.

5. The method of claim 1, wherein, each TX beam is associated with a different CG resource, wherein the subsequent UL transmission is performed using a different time-frequency resource than the first occasion of CG resources.

6. The method of claim 5, wherein, performing the subsequent UL transmission comprises selecting a CG resource having a same TB size as the first occasion of CG resources.

7. The method of claim 1, wherein, the timer comprises one of: a CG retransmission timer; and a beam failure timer different from the CG retransmission timer.

8. The method of claim 7, wherein, the beam failure timer is associated with a certain channel access priority class.

9. The method of claim 1, wherein, the UL transmission during the first occasion is associated with a first HARQ process, wherein performing an UL transmission during a second occasion and using the second beam comprises reusing the first HARQ process.

10. The method of claim 1, wherein, performing the LBT procedure comprises performing a clear channel assessment for a plurality of sensing beams, wherein performing the UL transmission of the first TB during the first occasion comprises selecting a single TX beam from a plurality of TX beams and transmitting the first TB using the selected TX beam.

11. The method of claim 10, wherein, the single TX beam from the plurality of TX beams is selected based on a lowest energy detection value from the clear channel assessment of the sensing beams; wherein there is a QCL type-D relationship between the plurality of sensing beams and the plurality of TX beams.

12. The method of claim 1, wherein, performing the LBT procedure comprises performing a clear channel assessment for a plurality of sensing beams, wherein performing the UL transmission of the first TB further comprises transmitting the first TB using at least one additional TX beam from the plurality of sensing beams that is LBT successful, wherein each TX beam is associated with a different CG resource.

13. The method of claim 12, further comprising: terminating retransmission of the first TB in response to receiving at least one HARQ-ACK feedback; and flushing all HARQ buffers associated with transmission of the first TB.

14. The method of claim 1, wherein, The UL transmission during the first occasion is accompanied by first uplink control information (UCI) that identifies a beam used for transmission on the CG resources.

15. The method of claim 1, wherein, A value of the timer corresponds to a channel access priority class used for the UL transmission.

16. The method of claim 1, further comprising: terminating the timer in response to receiving at least one HARQ-ACK feedback for the first TB; and flushing a HARQ buffer associated with transmission of the first TB in response to receiving the HARQ-ACK feedback for the first TB.

17. A user equipment (UE) apparatus, comprising: a transceiver capable of operating on unlicensed spectrum, wherein the transceiver comprises a plurality of UE panels; and a processor that: performs a listen before talk (LBT) procedure at a first UE prior to a first occasion of configured grant (CG) resources; performs an uplink (UL) transmission of a first transport block (TB) during the first occasion and using a first UE panel in response to a successful LBT; starts a timer in response to the UL transmission; determines a failure of the UL transmission if HARQ-ACK feedback is not received within a duration of the timer; and switches to a second UE panel for a subsequent UL transmission of the first TB in response to determining the failure of the UL transmission.

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