MAC control elements for multiple transmit or receive point operations in wireless communication systems

Abstract

A wireless communication system includes a terminal that may receive a Media Access Control (MAC) Control Element (CE) from a base station; identifying whether the MAC CE is associated with activation or deactivation of a unified transmission configuration indication (TCI) state based on a MAC sub-header with an extended logical channel identifier (eLCID) in the MAC CE; and receiving, from a base station, data based on the MAC CE associated with activation or deactivation of a unified TCI state, in a case where the MAC CE is associated with activation or deactivation of the unified TCI state, a MAC CE associated with activation or deactivation of a unified TCI state includes information about an identifier associated with a bandwidth portion (BWP), information about an identifier associated with a serving cell, information about an identifier associated with a TCI state, and information about an identifier associated with a control resource set (CORESET) pool.

Description

TECHNICAL FIELD

[0001] The present disclosure relates generally to a wireless communication system, and more particularly, the present disclosure relates to a medium access control (MAC) control element (CE) for multi-transmission / reception point (TRP) operation in a wireless communication system. BACKGROUND

[0002] 5G mobile communication technologies define wide frequency bands so that high transmission rates and new services are possible, and are implemented not only in "Sub 6 GHz" bands but also in "6 GHz and above" bands (including 28 GHz, 39 GHz, and 60 GHz bands). In addition, 6G mobile communication technologies (referred to as Beyond 5G systems) have been discussed, which will implement even greater frequency (for example, 95 GHz to 3 THz bands) to accomplish a faster transmission rate and lower latency than 5G mobile communication technologies.

[0003] At the early stage of 5G mobile communication technologies development, standardization for supporting services and satisfying requirements related to enhanced Mobile Broad Band (eMBB), Ultra-reliable low-latency communications (URLLC), and massive Machine-Type Communications (mMTC) has been completed, and standardization for 5G mobile communication technologies using new technologies such as 6G has been discussed.

[0004] Currently, discussions are underway for improvement and performance enhancement of initial 5G mobile communication technologies in view of services supported by 5G mobile communication technologies, and there has been standardization for physical layers regarding technologies such as Vehicle-to-everything (V2X) for assisting driving decisions by autonomous vehicles based on information about positions and states of vehicles transmitted by the vehicles and improving user convenience, New Radio Unlicensed (NR-U) aiming system operation conforming to various regulatory requirements in unlicensed bands, NR UE power saving, Non-Terrestrial Network (NTN) that is UE-satellite direct communication as a means for securing coverage in areas where terrestrial network communication is unavailable, and positioning.

[0005] In addition, technologies in air interface architecture / protocol aspects are being continuously standardized, such as Industrial Internet of Things (IIoT) for support of new services through interworking and convergence with other industries, IAB (Integrated Access and Backhaul) for network service area expansion providing nodes by supporting wireless backhaul links and access links in an integrated manner, mobility enhancement including conditional handover and DAPS (Dual Active Protocol Stack) handover, and two-step random access (2-step RACH for NR) for simplifying random access procedures. System architecture / services are also being continuously standardized with respect to 5G baseline architecture (e.g., service based architecture or service based interface) for convergence of network functions virtualization (NFV) and software-defined networking (SDN) technologies, as well as mobile edge computing (MEC) for receiving services based on UE location.

[0006] With the commercialization of 5G mobile communication systems, connected devices, which have increased exponentially, will be connected to communication networks, and thus it is expected that the functionality and performance of 5G mobile communication systems and integrated operations of connected devices will be required to be enhanced. For this, new research related to extended reality (XR) is planned in order to efficiently support AR (Augmented Reality), VR (Virtual Reality), MR (Mixed Reality), etc., by utilizing artificial intelligence (AI) and machine learning (ML), AI service support, virtual reality service support, and drone communication to improve 5G performance and reduce complexity.

[0007] In addition, such development of 5G mobile communication systems will serve as a basis for not only developing new waveforms for providing coverage in terahertz bands for 6G mobile communication technologies, multi-antenna transmission technologies such as Full Dimensional MIMO (FD-MIMO), array antennas and large-scale antennas, metamaterials-based lenses and antennas for improving coverage of terahertz band signals, high-dimensional space multiplexing technology using OAM (Orbital Angular Momentum), and RISs (Reconfigurable Intelligent Surfaces), but also developing full-duplex technologies for increasing frequency efficiency of 6G mobile communication technologies and improving system networks, AI-based communication technologies for implementing system optimization by utilizing satellites and AI (Artificial Intelligence) from the design stage and internalizing end-to-end AI support functions, and next-generation distributed computing technologies for implementing services by utilizing communication and computing resources with super-high performance at a level of complexity exceeding the limits of UE operation capabilities.

[0008] The momentum for 5th-Generation (5G) or New Radio (NR) mobile communication is recently increasing with worldwide technology activities for various candidate technologies from industry and academia. Candidate enablers for 5G / NR mobile communication include massive antenna technology, from legacy cellular frequency bands to high frequency, to provide beamforming gain and support increased capacity, new waveform (e.g., new radio access technology (RAT)) for flexible adaptation to various services / applications having different requirements, new multiple access schemes for supporting massive connection, and the like. The momentum for 5th-Generation (5G) or New Radio (NR) mobile communication is recently increasing with worldwide technology activities for various candidate technologies from industry and academia. Candidate enablers for 5G / NR mobile communication include massive antenna technology, from legacy cellular frequency bands to high frequency, to provide beamforming gain and support increased capacity, new waveform (e.g., new radio access technology (RAT)) for flexible adaptation to various services / applications having different requirements, new multiple access schemes for supporting massive connection, and the like. SUMMARY

[0009] TECHNICAL PROBLEM

[0010] According to the development of a communication system, a MAC CE for multi-transmission / reception point operation is needed.

[0011] The technical subject pursued in the disclosure can not be limited to the above-described technical subject, and other technical subjects not mentioned can be clearly understood by those skilled in the art to which the disclosure pertains through the following description.

[0012] TECHNICAL SOLUTION

[0013] The disclosure relates to a wireless communication system, and more particularly, the disclosure relates to a MAC CE for multi-TRP operation in a wireless communication system.

[0014] A method and apparatus for a MAC CE for multi-TRP operation in a wireless communication system are provided. A method of a UE includes receiving, from a BS belonging to a serving cell, a first MAC PDU including a first MAC subheader having a first eLCID and a first MAC CE, identifying, based on the first eLCID, an enhanced unified TCI state activation / deactivation MAC CE for joint TCI state or separate TCI state, the MAC CE including a bitmap of TCI state ID presence indication and TCI state IDs, wherein a bit in the bitmap of TCI state ID presence indication indicates whether a TCI state ID associated with a codepoint of a DCI TCI field exists in a corresponding MAC CE for a TRP, and a maximum number of activated TCI state IDs is 32, and indicating, to a lower layer, information associated with the corresponding MAC CE.

[0015] In one embodiment, a user equipment (UE) in a wireless communication system is provided. The UE includes a transceiver configured to receive, from a base station (BS) belonging to a serving cell, a first medium access control protocol data unit (MAC PDU) including a first MAC subheader having a first enhanced logical channel identifier (eLCID) and a first MAC CE. The UE also includes a processor, operably coupled with the transceiver, configured to: identify, based on the first eLCID, an enhanced unified TCI state activation / deactivation MAC CE for joint or separate TCI states, the MAC CE including a bitmap of transmission configuration indication (TCI) state identifier (ID) present indications and TCI state IDs, wherein a bit in the bitmap of TCI state ID present indications indicates whether a TCI state for a TRP is present in a corresponding MAC CE for a TCI state ID associated with a codepoint of a downlink control information (DCI) TCI field, and wherein a maximum number of activated TCI state IDs is 32; and indicate, to a lower layer, information associated with the corresponding MAC CE.

[0016] In another embodiment, a method of a UE in a wireless communication system is provided. The method includes receiving, from a BS belonging to a serving cell, a first MAC PDU including a first MAC subheader having a first enhanced eLCID and a first MAC CE; identifying, based on the first eLCID, an enhanced unified TCI state activation / deactivation MAC CE for joint or separate TCI states, the MAC CE including a bitmap of TCI state ID present indications and TCI state IDs, wherein a bit in the bitmap of TCI state ID present indications indicates whether a TCI state for a TRP is present in a corresponding MAC CE for a TCI state ID associated with a codepoint of a DCI TCI field, and wherein a maximum number of activated TCI state IDs is 32; and indicating, to a lower layer, information associated with the corresponding MAC CE.

[0017] In yet another embodiment, a BS in a wireless communication system is provided. The BS includes a processor configured to generate a first MAC PDU including a first MAC subheader having a first eLCID and a first MAC CE. The BS further includes a transceiver operably coupled to the processor, the transceiver configured to transmit, to a UE, the first MAC PDU including the first MAC subheader having the first eLCID and the first MAC CE, wherein the BS belongs to a serving cell, wherein an enhanced unified TCI state activation / deactivation MAC CE for joint or separate TCI states is identified based on the first eLCID, the MAC CE including a bitmap of TCI state ID presence indications and TCI state IDs, wherein a bit in the bitmap of TCI state ID presence indications indicates whether a TCI state ID associated with a codepoint of a DCI TCI field exists in the corresponding MAC CE for a TRP, wherein a maximum number of activated TCI state IDs is 32, and wherein information associated with the corresponding MAC CE is indicated to a lower layer.

[0018] A method performed by a terminal in a wireless communication system, the method comprising: receiving, from a base station, a medium access control (MAC) control element (CE); identifying, based on a MAC subheader having an extended logical channel identifier (eLCID) in the MAC CE, whether the MAC CE is associated with a unified transmission configuration indicator (TCI) state activation or deactivation; and in case that the MAC CE is associated with the unified TCI state activation or deactivation, receiving, from the base station, data based on the MAC CE associated with the unified TCI state activation or deactivation; wherein the MAC CE associated with the unified TCI state activation or deactivation includes information on an identifier associated with a bandwidth part (BWP), information on an identifier associated with a serving cell, information on an identifier associated with a TCI state, and information on an identifier associated with a control resource set (CORESET) pool.

[0019] identifying, based on the MAC subheader having the eLCID in the MAC CE, whether the MAC CE is associated with an enhanced unified TCI state activation or deactivation; and in case that the MAC CE is associated with the enhanced unified TCI state activation or deactivation, receiving, from the base station, data based on the MAC CE associated with the enhanced unified TCI state activation or deactivation.

[0020] wherein the MAC CE associated with the enhanced unified TCI state activation or deactivation includes information associated with a presence of a TCI state.

[0021] wherein the MAC CE associated with the enhanced unified TCI state activation or deactivation includes the information on the identifiers associated with the TCI states, wherein a maximum number of activated TCI states is 32.

[0022] A method performed by a base station in a wireless communication system, the method comprising: transmitting, to a terminal, a medium access control (MAC) control element (CE) associated with unified transmission configuration indicator (TCI) state activation or deactivation; and transmitting, to the terminal, data based on the MAC CE associated with the unified TCI state activation or deactivation; wherein the MAC CE associated with the unified TCI state activation or deactivation includes information on an identifier associated with a bandwidth part (BWP), information on an identifier associated with a serving cell, information on an identifier associated with a TCI state, and information on an identifier associated with a control resource set (CORESET) pool.

[0023] Other technical features can be readily apparent to one skilled in the art from the following figures, descriptions, and claims.

[0024] Before undertaking the below, it can be advantageous to set forth definitions of certain words and phrases used throughout this patent document: the term “couple” and its derivatives refer to any direct or indirect communication between two or more elements, regardless of the nature of the The terms “transmit,” “receive,” and “communicate,” and derivatives thereof, encompass both direct and indirect communication. The term “include” and derivatives thereof, mean inclusion without limitation. The term “or” is inclusive, meaning and / or. The phrase “associated with,” as well as derivatives thereof, means to include, be included within, interconnect with, contain, be contained within, connect to or with, couple to or with, be communicable with, cooperate with, interleave, juxtapose, be proximate to, be bound to or with, have a property of, have relations with, have agreements, among others. The term “controller” means any device, system or part thereof that controls at least one operation. Such a controller can be implemented in hardware or a combination of hardware and software and / or firmware. The functionality associated with any particular controller can be centralized or distributed, whether locally or remotely. The phrase “at least one of,” when used with a list of items, means that different combinations of one or more of the listed items can be used and only one item from the list can be needed. For example, “at least one of A, B, and C” includes: A alone, B alone, C alone, A and B together, A and C together, B and C together, and A and B and C together.

[0025] Moreover, various functions described below can be implemented or supported by one or more computer programs, each of which is formed from computer readable program code. The terms "application" and "program" refer to one or more computer programs, software components, sets of instructions, routines, functions, objects, classes, instances, related data, or a portion thereof, that are suitable for implementation on a suitable computer readable medium (media) and executed by a computer or computing device. The phrase "computer readable medium" includes any medium that is capable of storing the computer readable program code, such as a floppy disk, a ROM, a RAM, a hard disk drive, an optical disk (such as a CD or DVD), or any other medium. The phrase "non-transitory computer readable medium" excludes media that has only transitory signals, but includes media that has non-transitory signals. The phrase "computer readable medium" also includes, but is not limited to, portable and non-portable computer readable medium, tangible and non-tangible computer readable medium, optical and tangible computer readable medium, and analog and digital computer readable medium.

[0026] Definitions for other certain words and phrases are provided throughout this patent document. Those of ordinary skill in the art will understand that such definitions apply not only to the respective words and phrases that they follow, but to instances thereof throughout this document.

[0027] Advantages

[0028] The present disclosure provides efficient and effective methods associated with MAC CE for multi-transmission / reception point operation. Advantageous effects available from the present disclosure can not be limited to the above-mentioned effects, and other effects not mentioned can be clearly understood by those skilled in the art to which the present disclosure pertains from the following description. BRIEF DESCRIPTION OF DRAWINGS

[0029] For a more complete understanding of the present disclosure and its advantages, reference is now made to the following description taken in conjunction with the accompanying drawings in which like parts are marked with like numerals: Figure 1 An example of a wireless network is shown in accordance with an embodiment of the present disclosure; Figure 2 An example of a gNB is shown in accordance with an embodiment of the present disclosure; Figure 3 An example of a UE is shown in accordance with an embodiment of the present disclosure; Figure 4 And Figure 5 An example of a wireless transmit and receive path is shown in accordance with the present disclosure; Figures 6 to 14 An example of a unified TCI state activation / deactivation MAC CE is shown in accordance with an embodiment of the present disclosure; and Figure 15 A flow diagram of a UE method for a MAC CE for multi-TRP operation in a wireless communication system according to embodiments of the disclosure is shown. DETAILED DESCRIPTION

[0030] The Figures 1 to 15 The various embodiments discussed below are merely examples for illustration and should not be construed to limit the scope of the disclosure in any way. It will be appreciated by persons skilled in the art that the principles of the disclosure can be applied in any suitable arrangement of system or device.

[0031] To meet the demand for wireless data traffic having increased since deployment of 4G communication systems and to enable various vertical applications, 5G / NR communication systems have been developed and are currently being deployed. A 5G / NR communication system is considered to be implemented in higher frequency (millimeter wave) bands, e.g., 28 GHz or 60 GHz bands, so as to implement a higher data rate than a 4G communication system. To mitigate a propagation loss of radio waves and increase a transmission distance, beamforming, massive multiple-input multiple-output (MIMO), full dimensional MIMO (FD-MIMO), array antennas, an analog beam forming, large scale antennas techniques are discussed in 5G / NR communication systems.

[0032] In addition, in 5G / NR communication systems, development for system network improvement is under way based on advanced small cells, cloud radio access networks (RANs), ultra-dense networks, a device-to-device (D2D) communication, a wireless backhaul, a mobile network, a cooperative communication, coordinated multi-points (CoMP), reception-end interference cancellation, and the like.

[0033] The discussion of 5G systems and frequency bands associated therewith is for reference because certain embodiments of the disclosure can be implemented in 5G systems. However, the disclosure is not limited to 5G systems or frequency bands associated therewith, and embodiments of the disclosure can be used in conjunction with any frequency band. For example, aspects of the disclosure can also apply to deployments of 5G communication systems that can use terahertz (THz) bands, 6G or even higher versions.

[0034] The following documents are hereby incorporated by reference into this disclosure as if fully set forth at this point: “3GPP, TS 38.300 v17.5.0, 5G; NR; NR and NG-RAN Overall Description; Stage 2”; “3GPP, TS 38.331 v17.5.0, 5G; NR; Radio Resource Control (RRC); Protocol specification”; and “3GPP, TS 38.321 v17.5.0, NR; Medium Access Control (MAC) protocol specification”.

[0035] The following Figures 1 to 3 Various embodiments are described that implement in wireless communication systems and with Orthogonal Frequency Division Multiplexing (OFDM) or Orthogonal Frequency Division Multiple Access (OFDMA) communication technology. Figures 1 to 3 The description of the embodiments of the present disclosure is not intended to suggest that physical or architectural limitations of a manner in which different embodiments can be implemented. Different embodiments of the present disclosure can be implemented in any suitable arrangement.

[0036] Figure 1 An example wireless network according to embodiments of the present disclosure is illustrated. Figure 1 The embodiment of the wireless network shown is for illustration purposes only. Other embodiments of the wireless network 100 can be used without departing from the scope of the present disclosure.

[0037] As Figure 1 illustrated, the wireless network includes a gNB 101 (e.g., base station, BS), a gNB 102, and a gNB 103. The gNB 101 communicates with the gNB 102 and the gNB 103. The gNB 101 also communicates with at least one network 130, such as the Internet, a proprietary Internet Protocol (IP) network, or other data network.

[0038] The gNBs 102 provides wireless broadband access to the network 130 for a first plurality of user equipment units (UEs) within a coverage area 120 of the gNB 102. The first plurality of UEs includes a UE 111, which can be located in a small business; a UE 112, which can be located in a large business; a UE 113, which can be a WiFi hotspot; a UE 114, which can be located in a first residence; a UE 115, which can be located in a second residence; and a UE 116, which can be a mobile device, such as a cell phone, a wireless laptop, a wireless PDA, or the like. The gNB 103 provides wireless broadband access to the network 130 for a second plurality of UEs within a coverage area 125 of the gNB 103. The second plurality of UEs includes the UE 115 and the UE 116. In some embodiments, one or more of the gNBs 101-103 can communicate with each other and with the UEs 111-116 using 5G / NR, Long Term Evolution (LTE), Long Term Evolution-Advanced (LTE-A), WiMAX, WiFi, or other wireless communication techniques.

[0039] Depending on the network type, the term "base station" or "BS" can refer to any component (or collection of components) configured to provide wireless access to a network, such as a transmit point (TP), transmit-receive point (TRP), an enhanced base station (eNodeB or eNB), a 5G / NR base station (gNB), a macrocell, a femtocell, a WiFi access point (AP), or other wirelessly enabled devices. Base stations can provide wireless access to the Internet or to a packet-switched networking core or to other networks. A base station may

[0040] Dotted lines show the approximate extents of the coverage areas 120 and 125, which are shown as approximately circular for the purposes of illustration and explanation only. It is clearly to be understood that the coverage areas associated with gNBs, such as the coverage areas 120 and 125, can have other shapes, including irregular shapes, depending upon the configuration of the gNBs and variations in the radio environment associated with natural and man-made obstructions.

[0041] As described in more detail below, one or more of the UEs 111-116 include circuitry, programing or a combination thereof, to support MAC CEs for multi-TRP operation in a wireless communication system. In certain embodiments, one or more of the gNBs 101-103 includes circuitry, programing or a combination thereof, to support MAC CEs for multi-TRP operation in a wireless communication system.

[0042] Although Figure 1 various changes can be made to Figure 1 the wireless network. For example, the wireless network can include any number of gNBs and any number of UEs in any suitable arrangement. In addition, gNB 101 could communicate directly with any number of UEs and provide those UEs access to network 130. Similarly, gNBs 102-103 could each communicate directly with network 130 and provide UEs access to network 130. Further, gNBs 101, 102, and / or 103 could provide access to other or additional external networks, such as external telephone networks or other types of data networks.

[0043] Figure 2 An example gNB 102 according to embodiments of the present disclosure is illustrated. Figure 2 The illustrated embodiment of the gNB 102 is for illustration only, and Figure 1 The gNBs 101 and 103 can have the same or similar configuration. However, gNBs can have a wide variety of configurations and Figure 2 without limiting the scope of this disclosure to any particular implementation of a gNB.

[0044] As Figure 2 illustrated, gNB 102 includes multiple antennas 205a-205n, multiple transceivers 210a-210n, a controller / processor 225, memory 230, and a backhaul or network interface 235.

[0045] The transceivers 210a-210n receive, from the antennas 205a-205n, incoming RF signals such as signals transmitted by UEs in the network 100. The transceivers 210a-210n down-convert the incoming RF signals to generate IF or baseband signals. The IF or baseband signals are processed by the transceivers 210a-210n and / or by receive (RX) processing circuitry in the controller / processor 225 that generates processed baseband signals by filtering, decoding, and / or digitizing the baseband or IF signals. The controller / processor 225 can further process the baseband signals.

[0046] Transmit (TX) processing circuitry in the transceivers 210a-210n and / or the controller / processor 225 receives analog or digital data, such as voice data, web data, e-mail, or interactive video game data from the controller / processor 225. The TX processing circuitry encodes, multiplexes, and / or digitizes the outgoing baseband data to generate processed baseband or IF signals. The transceivers 210a-210n

[0047] The controller / processor 225 can include one or more processors or other processing devices to manage the overall operation of the gNB 102. For example, the controller / processor 225 can control the reception of

[0048] The controller / processor 225 can further perform programmable functions residing in the memory 230, such as an OS. The controller / processor 225 can move data into or out of the memory 230 as required by the processes being executed. The controller / processor 225 can also perform program and other processes resident in the memory 230, such as processes for supporting MAC CEs for multi-TRP operation in a wireless communication system.

[0049] The controller / processor 225 is also coupled to the backhaul or network interface 235. The backhaul or network interface 235 allows the gNB 102 to communicate with other devices or systems over a backhaul connection or over a network. It should be appreciated that the interface 235 could be used to support communications with many types of devices, including but not limited to other gNBs, UEs, AMFs, etc. The interface 235 could support communications through a wired or wireless connection. For example, the interface 235 could allow the gNB 102 to communicate with other gNBs of the network over a wired or wireless backhaul connection. When the gNB 102 is implemented as part of a cellular communication system, such as a cellular communication system supporting 5G / NR, LTE, or LTE-A, the interface 235 can allow the gNB 102 to communicate with other gNBs of the network over a wired or wireless backhaul connection. When the gNB 102 is implemented as an access point, the interface 235 can allow the gNB 102 to communicate with other gNBs of the network, or to a larger network such as the Internet, through a wired or wireless local area network, or through a wired or wireless connection. The interface 235 includes any suitable structure supporting communications over a wired or wireless connection, such as an Ethernet or coaxial connection, a wireless transceiver, etc.

[0050] The memory 230 is coupled to the controller / processor 225. Part of the memory 230 could include RAM, and another part of the memory 230 could include flash memory or other ROM.

[0051] Although Figure 2 various changes can be made to the gNB 102 Figure 2 could include any number of Figure 2 the components shown. Additionally, Figure 2 various components of the gNB 102 could be combined, further subdivided, or omitted and additional components could be added according to particular needs.

[0052] Figure 3 An example UE 116 according to embodiments of the present disclosure is shown. Figure 3 The embodiment of the UE 116 shown is for illustration only, and Figure 1 The UEs 111-115 could have the same or similar configuration. However, UEs come in a wide variety of configurations, and Figure 3 the scope of the present disclosure is not limited to any particular implementation of a UE.

[0053] As Figure 3 shown, the UE 116 includes an antenna 305, a transceiver 310, and a microphone 320. The UE 116 also includes a speaker 330, a processor 340, an input / output (I / O) interface (IF) 345, an input 350, a display 355, and a memory 360. The memory 360 includes an operating system (OS) 361 and one or more applications 362.

[0054] The transceiver 310 receives, from the antenna 305, an incoming RF signal transmitted by a gNB of the network 100. The transceiver 310 down-converts the incoming RF signal to generate a raw intermediate frequency (IF) or baseband signal. The IF or baseband signal is processed by the RX processing circuitry in the transceiver 310 and / or the processor 340, which generates a processed baseband signal by filtering, decoding, and / or digitizing the baseband or IF signal. The RX processing circuitry transmits the processed baseband signal to the speaker 330 (such as for voice data) or to the processor 340 (such as for web browsing data) to be processed.

[0055] The TX processing circuitry in the transceiver 310 and / or processor 340 receives analog or digital voice data from the microphone 320 or other outgoing baseband data (such as web data, e-mail, or interactive video game data) from the processor 340. The TX processing circuitry encodes, multiplexes, and / or digitizes the outgoing baseband data to generate a processed baseband or IF signal. The transceiver 310 up-converts the baseband or IF signal to an RF signal that is transmitted via the antenna 305.

[0056] The processor 340 can include one or more processors or other processing devices and execute instructions stored in memory 360 to control the overall operation of the UE 116. For example, the processor 340 can control the reception of DL channel signals and the transmission of UL channel signals by the transceiver 310, according to well-known principles. In some embodiments, the processor 340 includes at least one microprocessor or microcontroller.

[0057] The processor 340 is also capable of executing other processes and programs stored in memory 360, such as a process for MAC CE for multi-TRP operation in a wireless communication system. The processor 340 can move data into or out of memory 360 as required by the processes it executes. In some embodiments, the processor 340 is configured to execute the applications 362 based on the OS 361 or in response to signals received from gNBs or an operator. The processor 340 is further coupled to an I / O interface 345, which provides the UE 116 with the ability to connect to other devices such as laptop computers and handheld computers. The I / O interface 345 is the communication path between these accessories and the processor 340.

[0058] The processor 340 is also coupled to the input 350 (which includes, e.g., a touchscreen, a keyboard, etc.) and the display 355. The operator of the UE 116 can use the input 350 to enter data into the UE 116. The display 355 can be a liquid crystal display, light emitting diode display, or other display capable of rendering text and / or at least limited graphics, such as from web sites.

[0059] Memory 360 is coupled to the processor 340. Part of the memory 360 can include random access memory (RAM), and another part of the memory 360 can include non-volatile memory such as flash memory or other read-only memory (ROM).

[0060] Although Figure 3 various changes can be made to Figure 3 the TRP 116 as Figure 3 illustrated. For example, Figure 3 various components in the UE 116 can be combined, further subdivided, or omitted and additional components can be added according to particular needs. As a particular example, the processor 340 can be divided into multiple processors such as one or more central processing units (CPUs) and one or more graphics processing units (GPUs). In another example, the transceiver 310 can include any number of transceivers and signal processing chains and can be connected to any number of antennas. In addition, while the UE 116 is illustrated as a mobile telephone or smartphone, a UE can be configured to operate as other types of mobile or stationary devices.

[0061] Figure 4 and Figure 5 An exemplary wireless transmit and receive path is illustrated in accordance with the present disclosure. In the following description, the transmit path 400 can be described as implemented in a gNB (such as gNB 102), while the receive path 500 can be described as implemented in a UE (such as UE 116). It will be understood, however, that the receive path 500 can be implemented in a gNB and the transmit path 400 can be implemented in a UE. In some embodiments, the receive path 500 is configured to support MAC CEs for multi-TRP operation in a wireless communication system.

[0062] As Figure 4 illustrated, the transmit path 400 includes a channel coding and modulation block 405, a serial-to-parallel (S-to-P) block 410, a size N inverse fast Fourier transform (IFFT) block 415, a parallel-to-serial (P-to-S) block 420, an add cyclic prefix block 425, and a frequency up-converter (UC) 430. As Figure 5 illustrated, the receive path 500 includes a frequency down-converter (DC) 555, a remove cyclic prefix block 560, a serial-to-parallel (S-to-P) block 565, a size N fast Fourier transform (FFT) block 570, a parallel-to-serial (P-to-S) block 575, and a channel decoding and demodulation block 580.

[0063] As Figure 4As shown, the channel coding and modulation block 405 receives a set of information bits, applies coding (such as a low-density parity check (LDPC) coding), and modulates the input bits (such as with quadrature phase shift keying (QPSK) or quadrature amplitude modulation (QAM)) to generate a sequence of frequency-domain modulation symbols.

[0064] The serial-to-parallel block 410 converts (such as de-multiplexes) the serial modulated symbols into parallel data to generate N parallel symbol streams, where N is the IFFT / FFT size used in the gNB 102 and the UE 116. The size N IFFT block 415 performs an IFFT operation on the N parallel symbol streams to generate time-domain output signals. The parallel-to-serial block 420 converts (such as multiplexes) the parallel time-domain output symbols from the size N IFFT block 415 to generate a serial time-domain signal. The add cyclic prefix block 425 inserts a cyclic prefix to the time-domain signal. The up-converter 430 modulates (such as up-converts) the output of the add cyclic prefix block 425 to an RF frequency to be transmitted on a wireless channel. The signal can also be filtered at baseband before conversion to the RF frequency.

[0065] The RF signal transmitted from the gNB 102 arrives at the UE 116 after passing through the wireless channel, and the reverse operation to that performed at the gNB 102 is performed at the UE 116.

[0066] As Figure 5 shown, the down-converter 555 down-converts the received signal to baseband frequency and the remove cyclic prefix block 560 removes the cyclic prefix to generate a serial time-domain baseband signal. The serial-to-parallel block 565 converts the time-domain baseband signal to parallel time-domain signals. The size N FFT block 570 performs the FFT algorithm to generate N parallel frequency-domain signals. The parallel-to-serial block 575 converts the parallel frequency-domain signals to a sequence of modulated data symbols. The channel decoding and demodulation block 580 demodulates and decodes the modulated symbols to recover the original input data stream.

[0067] Each of the gNBs 101-103 can implement a transmit path 400 similar to that shown in FIG. 4 for transmitting in the downlink to UEs 111-116, and can implement a receive path 500 similar to that shown in FIG. 5 for receiving in the uplink from UEs 111-116. Figure 4 As shown, the transmit path 400 receives data bits from a data source 405, modulates and encodes the data bits to generate a sequence of symbols, and outputs the modulated and encoded symbols to a transmitter and antenna for transmission. Figure 5 Similarly, each of the UEs 111-116 can implement the transmit path 400 for transmitting in the uplink to the gNBs 101-103, and can implement the receive path 500 for receiving in the downlink from the gNBs 101-103.

[0068] Each of the components in Figure 4 and Figure 5 may be implemented using only hardware or using a combination of hardware and software / firmware. As a particular example, Figure 4 and Figure 5 at least some of the components in may be implemented in software, while others can be implemented by configurable hardware or a mixture of software and configurable hardware. For example, the FFT block 570 and the IFFT block 415 can be implemented as configurable software algorithms, where the value of the size N can be modified according to the implementation.

[0069] Moreover, while described as using FFTs and IFFTs, this is by way of illustration only and can not be construed as limiting the scope of the disclosure. Other types of transforms can be used, such as discrete Fourier transform (DFT) and inverse discrete Fourier transform (IDFT) functions. It can be appreciated that the value of the variable N can be any integer (such as 1, 2, 3, 4, etc.) for DFT and IDFT functions, while the value of the variable N can be any integer that is a power of two (such as 1, 2, 4, 8, 16, etc.) for FFT and IFFT functions.

[0070] Although Figure 4 and Figure 5 exhibit examples of wireless transmit and receive paths, Figure 4 and Figure 5 may be made. For example, Figure 4 and Figure 5 various components in Figure 4 and Figure 5 are intended to exhibit examples of types of transmit and receive paths that can be used in a wireless network. Any other suitable architecture can be used to support wireless communication in a wireless network.

[0071] 3GPP has developed technical specifications and standards for defining a new 5G radio access technology, referred to as 5G New Radio (NR). Multiple Input Multiple Output (MIMO) is one of the key technologies in NR systems and has been successful in commercial deployments. In multi-TRP (multi-TRP) operation, a serving cell can schedule a UE from two TRPs in order to provide better coverage, reliability, and data rates for transmission / reception of downlink and uplink. Two modes of operation are supported to schedule multi-TRP transmission: single-DCI, where a UE is scheduled by the same DCI for both TRPs; and multi-DCI, where a UE is scheduled by independent DCIs from each TRP.

[0072] In Rel-17, a unified transmission configuration indication (TCI) framework is supported to indicate unified TCI states for DL / UL transmission and reception.

[0073] In Rel-17, a unified TCI state activation / deactivation MAC CE is introduced for unified TCI state activation and deactivation. It is expected to apply the unified TCI framework to multi-TRP operation. It is expected to enhance the MAC CE to support unified TCI state activation and deactivation for multi-TRP operation.

[0074] In Rel-17, inter-cell multi-TRP operation is introduced, where one TRP is from the serving cell and the other TRP can be from a cell with PCI other than the serving cell, i.e., a non-serving cell, without changing the serving cell. For downlink multi-DCI transmission, one or multiple TCI states can be associated with SSBs from non-serving cells. An activated TCI state can be associated with at most one non-serving cell at a time. For uplink transmission, the UE transmits the same content towards two TRPs with corresponding beam directions associated with different spatial relations.

[0075] In Rel-18 NTN enhancements, a satellite without PCI change is considered, where beam-level mobility is needed without L3 mobility. However, when switching to a target satellite, the UE needs to perform UL synchronization by a random access procedure or by a RACH-less procedure when the target satellite is available.

[0076] In the present disclosure, enhancements to the unified TCI state activation / deactivation MAC CE are provided to support unified TCI state activation and deactivation for multi-TRP operation.

[0077] The UE receives a MAC CE (e.g., an enhanced unified TCI state activation / deactivation MAC CE) in a MAC PDU on the serving cell and indicates information about the received MAC CE to lower layers.

[0078] In an embodiment, some reserved bits can be used for new indications in the existing unified TCI state activation / deactivation MAC CE. In another embodiment, a new MAC CE, e.g., an enhanced unified TCI state activation / deactivation MAC CE, can be introduced, which can be identified by an LCID or eLCID included in a MAC subheader contained in the MAC PDU. In the present disclosure, the enhanced unified TCI state activation / deactivation MAC CE can be dedicated to joint TCI states or to individual TCI states for the unified TCI state framework.

[0079] Figure 4 Examples of unified TCI state activation / deactivation MAC CEs 600-1200 according to embodiments of the present disclosure are shown. As shown in FIG. 6, the unified TCI state activation / deactivation MAC CE 600 includes a MAC subheader 610 and a payload 620. The MAC subheader 610 includes a MAC subheader type 611, a MAC subheader length 612, and an LCID 613. The payload 620 includes a reserved bit 621, a number of activated TCI states 622, and a TCI state ID 623.Figure 5 The illustrated embodiments are for illustration only.

[0080] As Figure 6 to 12 shown, an example of (enhanced) unified TCI state activation / deactivation MAC CE is shown. The fields in the MAC CE are described as follows.

[0081] The (enhanced) unified TCI state activation / deactivation MAC CE is identified by a MAC subheader with eLCID as specified in 3GPP standard specifications. The MAC CE includes a variable size including the following fields.

[0082] In one example, the MAC CE includes a CORESET pool ID. The field indicates that the mapping between activated TCI states and codepoints of DCI transmission configuration indication set by field TCI State ID (TCI State ID) is specific to ControlResourceSetId configured with CORESET pool ID as specified in TS 38.331. The field set to 1 indicates that the MAC CE can be applied to DL transmissions scheduled by CORESET with CORESET pool ID equal to 1, otherwise, the MAC CE can be applied to DL transmissions scheduled by CORESET with CORESET pool ID equal to 0. If no CORESET in the corresponding BWP is configured with CORESET pool ID Figures 6 to 12 , or if no more than one Figure 6 is configured for any CORESET in the corresponding BWP, or if the value of coresetPoolIndex is configured for any CORESET in the corresponding BWP, the MAC entity can ignore the CORESET pool ID field in the MAC CE upon reception of the MAC CE. If the serving cell in the MAC CE is configured in a cell list containing more than one serving cell, the CORESET pool ID field can be ignored upon reception of the MAC CE.

[0083] In one example, the MAC CE includes a M / S field. When the field CORESET pool ID is ignored, this field indicates whether the TCI state IDs indicated in this MAC CE are for a single TRP or for two TRPs (i.e., a TCI state ID for a second TRP is present in this MAC CE). The field set to 0 indicates that the TCI state IDs are for a single TRP. The field set to 1 indicates that the TCI state IDs are for two TRPs (i.e., a TCI state ID for a second TRP is present in this MAC CE).

[0084] In one example, the MAC CE includes a serving cell ID. This field indicates the identity of the serving cell to which the MAC CE applies. The length of the field is 5 bits. If the indicated serving cell is configured as part of a coresetPoolIndex , coresetPoolIndex , simultaneousU-TCI-UpdateList1 simultaneousU-TCI-UpdateList2 or simultaneousU- , then the MAC CE applies to all serving cells in the set TCI-UpdateList3 , simultaneousU-TCI-UpdateList4 , simultaneousU-TCI-UpdateList1 simultaneousU-TCI-UpdateList2 or simultaneousU- , respectively.

[0085] In one example, the MAC CE includes a DL BWP ID field. This field indicates the DL BWP to which the MAC CE applies as a codepoint of the DCI TCI-UpdateList3 field as specified in TS 38.212. The length of the BWP ID field is 2 bits.

[0086] In one example, the MAC CE includes a UL BWP ID field. This field indicates the UL BWP to which the MAC CE applies as a codepoint of the DCI simultaneousU-TCI-UpdateList4 field as specified in TS 38.212. If the value bandwidth part indicator of the serving cell indicated by the serving cell ID is , bandwidth part indicator , the field is considered as a reserved bit. The length of the BWP ID field is 2 bits.

[0087] In one example, the MAC CE includes a P i field. This field indicates whether each TCI codepoint has multiple TCI states or a single TCI state. As shown in unifiedTCI-StateType and unified , there is one octet of the Pi field. If the M / S field is set to 0 and if the P i field is set to 1, this indicates that the ith TCI codepoint includes DL TCI states and UL TCI states for a single TRP. If the M / S field is set to 0 and if the P i field is set to 0 for i = 1, …, 8, this indicates that the ith TCI codepoint includes only DL / joint TCI states or UL TCI states for a single TRP. If the M / S field is set to 1 and if the P iIf the M / S field is set to 1, and if for i = 1,..., 8, the P i field is set to 0, this indicates that the ithTCI codepoint includes one DL / joint TCI state or one UL TCI state for the first TRP and another DL / joint TCI state or another UL TCI state for the second TRP.

[0088] Optionally, as shown in Figure 6 , Figure 7 and Figure 8 , there can be two octets of the Pi field. Only in the case that the M / S field is set to 1, there are octets of the P i field for i = 9,..., 16. If the M / S field is set to 0, and if for i = 1,..., 8, the P i field is set to 1, this indicates that the ithTCI codepoint includes a DL TCI state and a UL TCI state for a single TRP. If the M / S field is set to 0, and if for i = 1,..., 8, the P i field is set to 0, this indicates that the ithTCI codepoint includes only a DL / joint TCI state or a UL TCI state for a single TRP. If the M / S field is set to 1, for i = 1,..., 8, the P i field is set to 1 indicates that the ithTCI codepoint includes a pair of DL TCI state and UL TCI state for the first TRP; for i = 9,..., 16, the P i field is set to 1 indicates that the (i-8)thTCI codepoint includes another pair of DL TCI state and UL TCI state for the second TRP; for i = 1,..., 8, the P i field is set to 0 indicates that the ithTCI codepoint includes one DL / joint TCI state or one UL TCI state for the first TRP; for i = 9,..., 16, the P i field is set to 0 indicates that the (i-8)thTCI codepoint includes another DL / joint TCI state or another UL TCI state for the second TRP.

[0089] In one example, the MAC CE includes a D / U field. This field indicates whether the TCI state ID in the same octet is for joint / downlink or uplink TCI state. If this field is set to 1, the TCI state ID in the same octet is for joint / downlink. If this field is set to 0, the TCI state ID in the same octet is for uplink; In one example, the MAC CE includes a TCI state ID field. This field indicates the TCI state identified as specified in TS 38.331 Figure 9 If D / U is set to 1, a 7-bit length TCI state ID as specified in TS 38.331 Figure 10 is used. If D / U is set to 0, the most significant bit of the TCI state ID is considered as a reserved bit and the remaining 6 bits indicate the TCI-StateId .

[0090] For the examples shown in TCI-StateId and UL-TCIState-Id , if the field M / S is set to 0, the TCI state ID for a single TRP is indicated by N octets. If the field M / S is set to 1, the TCI state ID for the first TRP is indicated in the first N octets and the TCI state ID for the second TRP is indicated in the subsequent M octets containing the TCI state ID. The TCI state ID in the first N octets for different codepoints is indicated in ascending order of i. The TCI state ID in the subsequent M octets for different codepoints is indicated in ascending order of i. Optionally (as shown in Figure 6 ), if the field M / S is set to 0, the TCI state ID for a single TRP is indicated by N octets. If the field M / S is set to 1, the TCI state ID for codepoint i of the first TRP is followed by the TCI state ID for codepoint i of the second TRP, i.e., if Pi is set to 1, TCI state ID n+1 is for the first TRP and TCI state ID n+2 is for the second TRP, there is no TCI state n+3 and TCI state n+4, and so on; if Pi is set to 0, TCI state ID n+1 and TCI state ID n+2 are for the first TRP, TCI state n+3 and TCI state n+4 are for the second TRP, and so on. The TCI state ID for different codepoints is indicated in ascending order of i.

[0091] Optionally, as shown in Figure 8 and Figure 5As shown, if the field M / S is set to 0, the TCI state IDs for a single TRP are indicated by N octets. If the field M / S is set to 1, the TCI state ID for codepoint i of the first TRP is followed by the TCI state ID for codepoint i of the second TRP, i.e., if for i = 1,..., 8, P i is set to 1 and P i+8 is set to 1, then TCI state ID n+1 is for the first TRP and TCI state ID n+2 is for the second TRP, there is no TCI state n+3 and TCI state n+4; if for i = 1,..., 8, P i is set to 1 and P i+8 is set to 0, then TCI state ID n+1 is for the first TRP and TCI state ID n+2 and TCI state ID n+3 are for the second TRP, there is no TCI state n+4; if for i = 1,..., 8, P i is set to 0 and P i+8 is set to 1, then TCI state ID n+1 and TCI state ID n+2 are for the first TRP and TCI state ID n+3 is for the second TRP, there is no TCI state n+4; if for i = 1,..., 8, P i is set to 0 and P i+8 is set to 0, then TCI state ID n+1 and TCI state ID n+2 are for the first TRP and TCI state ID n+3 and TCI state n+4 are for the second TRP; and so on. The TCI state IDs for different codepoints are indicated in ascending order of i.

[0092] In one example, the maximum number of activated TCI states is 32.

[0093] In one example, the MAC CE includes an R field. This field is a reserved bit set to 0.

[0094] In another embodiment, as Figure 9 shown, the (enhanced) unified TCI state activation / deactivation MAC CE is identified by a MAC subheader with eLCID as specified in 3GPP standard specification. The MAC CE includes a variable size, which is composed of one or more of the following fields.

[0095] In one example, the MAC CE includes a M / S field. This field indicates whether the TCI state ID indicated in this MAC CE is for a single TRP or for two TRPs. This field is set to 0 to indicate that the TCI state ID is for a single TRP. This field is set to 1 to indicate that the TCI state ID is for two TRPs (i.e., there is a TCI state ID for the second TRP).

[0096] In one example, the MAC CE includes a CORESET pool ID field. When the M / S field is set to 0, this field indicates that the TCI state ID indicated in this MAC CE is specific to the ControlResourceSetId configured with a CORESET pool ID as specified in TS 38.331. When the M / S field is set to 1, this field is considered as a reserved bit. This field is set to 1 to indicate that the TCI state ID indicated in this MAC CE is specific to CORESET pool ID 1, otherwise, the TCI state ID indicated in this MAC CE is specific to CORESET pool ID 0. The MAC entity can ignore this field if Figure 10 , or if no more than one Figure 11 , or if the value is only zero coresetPoolIndex is configured for any CORESET in the corresponding BWP. The CORESET pool ID field can be ignored when receiving the MAC CE if the serving cell in the MAC CE is configured in a list of cells containing more than one serving cell.

[0097] In one example, the MAC CE includes a serving cell ID field. This field indicates the identity of the serving cell to which the MAC CE applies. The length of the field is 5 bits. If the indicated serving cell is configured as part of coresetPoolIndex , coresetPoolIndex , simultaneousU-TCI-UpdateList1 simultaneousU-TCI-UpdateList2 or simultaneousU- , this MAC CE applies to all serving cells in the set TCI-UpdateList3 , simultaneousU-TCI-UpdateList4 , simultaneousU-TCI-UpdateList1 simultaneousU-TCI-UpdateList2 or simultaneousU- , respectively; In one example, the MAC CE includes a DL BWP ID field. This field indicates the DL BWP to which the MAC CE applies as the codepoint of the DCI TCI-UpdateList3 field as specified in TS 38.212. The length of the BWP ID field is 2 bits; In one example, the MAC CE includes a UL BWP ID field. This field indicates the UL BWP to which the MAC CE applies as a codepoint of the DCI simultaneousU-TCI-UpdateList4 field as specified in TS 38.212. If there is no serving cell with the serving cell ID indicated in the field bandwidth part indicator , the value is bandwidth part indicator , the field is considered as a reserved bit. The length of the BWP ID field is 2 bits.

[0098] In one example, the MAC CE includes a C i-k field. This field indicates whether there is a TCI state ID for the i-th TCI codepoint for the k-th TRP corresponding to the CORESET pool ID k-1, where k = 1, 2 and i = 1, …, 8. The field is set to 1 to indicate that there is a TCI state ID for the i-th TCI codepoint for the k-th TRP; the field is set to 0 to indicate that there is no TCI state ID for the i-th TCI codepoint for the k-th TRP. Here, the TCI state ID is for joint TCI state, DL TCI state or separate TCI state. If the M / S field is set to 0 and the CORESET pool ID is set to 0, there are eight octets for C i-1 and eight octets for P i-1 , there are no eight octets for C i-2 and eight octets for P i-2 ; if the M / S field is set to 0 and the CORESET pool ID is set to 1, there are no eight octets for C i-1 and eight octets for P i-1 , there are eight octets for C i-2 and eight octets for P i-2 . If the M / S field is set to 1, there are all eight octets for C i-k and P i-1 .

[0099] In one example, the MAC CE includes a P i-k field. This field indicates for the k-th TRP corresponding to the CORESET pool ID k-1, if C i-k is set to 1, it indicates whether the i-th TCI codepoint is with two TCI state IDs or a single TCI state ID. If the unified TCI state is configured by the upper layer parameter to be unifiedTCI-StateType , there is no this field. If the unified TCI state is configured by the upper layer parameter to be unified , there is this field. If C i-k is set to 0, P i-k is considered as a reserved bit.i-k It is set to 1, and if P i-k If the field is set to 0, this indicates a TCI status ID for the i-th TCI code point of the k-th TRP. If C i-k It is set to 1, and if P i-k If the field is set to 1, this indicates that two TCI status IDs are indicated for the i-th TCI code point of the k-th TRP.

[0100] In one example, the MAC CE includes a D / U field. This field indicates whether the TCI status ID in the same octet is used for the union / downlink or uplink TCI status. If this field is set to 1, the TCI status ID in the same octet is used for the union / downlink. If this field is set to 0, the TCI status ID in the same octet is used for the uplink.

[0101] In one example, the MAC CE includes a TCI status ID field. This field indicates the status ID specified as in TS 38.331. unified The TCI status identifier. If D / U is set to 1, the 7-bit TCI status ID, as specified in TS 38.331, can be... separate If D / U is set to 0, the most significant bit of the TCI status ID is treated as a reserved bit, and the remaining 6 bits indicate as specified in TS 38.331. TCI-StateId .for TCI-StateId and UL-TCIState-Id The example shown illustrates that if the M / S field is set to 0, the TCI status ID for a single TRP is indicated by N octets. If the M / S field is set to 1, the TCI status ID for the first TRP is indicated in the first N octets, and the TCI status ID for the second TRP is indicated in the subsequent M octets containing the TCI status ID. The TCI status IDs for different code points are indicated in ascending order of i in the first N octets. The TCI status IDs for different code points are also indicated in ascending order of i in the subsequent M octets.

[0102] In one example, the maximum number of active TCI states is 32.

[0103] In one example, the MAC CE includes an R field. The R field is a reserved bit that is set to 0.

[0104] In another embodiment, such as Figure 6As shown, the (enhanced) unified TCI state activation / deactivation MAC CE is identified by a MAC subheader with eLCID as specified in 3GPP standard specifications. The MAC CE includes a variable size, which includes one or more of the following fields.

[0105] In one example, the MAC CE includes a serving cell ID field. This field indicates the identity of the serving cell to which the MAC CE applies. The length of the field is 5 bits. If the indicated serving cell is configured as part of a Figure 8 , Figure 12 simultaneousU-TCI-UpdateList1 simultaneousU-TCI-UpdateList2 , simultaneousU- TCI-UpdateList3 or simultaneousU-TCI-UpdateList4 , then the MAC CE applies to all serving cells in the set simultaneousU-TCI-UpdateList1 , simultaneousU-TCI-UpdateList2 , simultaneousU- TCI-UpdateList3 or simultaneousU-TCI-UpdateList4 , respectively.

[0106] In one example, the MAC CE includes a DL BWP ID field. This field indicates the DL BWP to which the MAC CE applies as a codepoint of the DCI bandwidth part indicator field as specified in TS 38.212. The length of the BWP ID field is 2 bits.

[0107] In one example, the MAC CE includes a UL BWP ID field. This field indicates the UL BWP to which the MAC CE applies as a codepoint of the DCI bandwidth part indicator field as specified in TS 38.212. If the value of unifiedTCI-StateType for the serving cell indicated by the serving cell ID field is , unified then the field is considered as a reserved bit. The length of the BWP ID field is 2 bits.

[0108] In one example, the MAC CE includes a C i-k field. This field indicates whether there is a TCI state ID for the i-th TCI codepoint for the k-th TRP corresponding to the CORESET pool ID k-1, where k = 1, 2 and i = 1, …, 8. The field is set to 1 to indicate that there is a TCI state ID for the i-th TCI codepoint for the k-th TRP; the field is set to 0 to indicate that there is no TCI state ID for the i-th TCI codepoint for the k-th TRP. Here, the TCI state ID is for joint TCI state, DL TCI state or separate TCI state.

[0109] In one example, the MAC CE includes a P i-kField. This field indicates if, for the k-th TRP corresponding to the CORESET pool ID k-1, the i-th TCI codepoint indicates one or two TCI state IDs. i-k If set to 1, it indicates if the i-th TCI codepoint has two TCI state IDs or a single TCI state ID. If the unified TCI state is configured through upper layer parameter unified , this field is not present. If the unified TCI state is configured through upper layer parameter separate , this field is present. If C i-k is set to 0, P i-k (if present) is considered as reserved bits. If C i-k is set to 1, and if P i-k field is set to 0, this indicates that the i-th TCI codepoint for the k-th TRP indicates one TCI state ID. If C i-k is set to 1, and if P i-k field is set to 1, this indicates that the i-th TCI codepoint for the k-th TRP indicates two TCI state IDs.

[0110] In one example, the MAC CE includes a D / U field. This field indicates if the TCI state IDs in the same octet are for joint / downlink or uplink TCI states. If this field is set to 1, the TCI state IDs in the same octet are for joint / downlink. If this field is set to 0, the TCI state IDs in the same octet are for uplink.

[0111] In one example, the MAC CE includes a TCI state ID field. This field indicates the TCI state identified as TCI-StateId as specified in TS 38.331. If D / U is set to 1, a 7-bit length TCI state ID as specified in TS 38.331, i.e. TCI-StateId is used. If D / U is set to 0, the most significant bits of the TCI state ID are considered as reserved bits and the remaining 6 bits indicate the UL-TCIState-Id as specified in TS 38.331. In one example, the TCI state IDs for one TRP are indicated in the first N octets in ascending order of i. The TCI state IDs for other TRPs are indicated in the subsequent M octets in ascending order of i. In another example, the TCI state IDs are indicated in ascending order of codepoint index I, where for each codepoint, the TCI state ID for the first TRP is followed by the TCI state ID for another TRP. The maximum number of activated TCI states per TRP is 16.

[0112] In one example, the maximum number of activated TCI states is 32.

[0113] In one example, the MAC CE includes an R field. This field is a reserved bit set to 0.

[0114] For dual connectivity, the UE needs to handle the maximum UL timing difference between PCell and PSCell as specified in TS 38.133. That is, given that the UE indicates that the UE is capable of asynchronous NR DC, the UE can be able to handle the maximum uplink transmission timing difference between PCell and PSCell as shown in Table 1.

[0115] Table 1. Maximum uplink transmission timing difference requirement for inter-band asynchronous NR DC

[0116] In TS 38.321, the related requirement for TAT expiry is specified as follows. When the MAC entity stops uplink transmission for a SCell due to the fact that the maximum uplink transmission timing difference between TAGs of the MAC entity or the maximum uplink transmission timing difference between TAGs of any MAC entity of the UE is exceeded, the MAC entity considers the timeAlig nmentTimer associated with the SCell as expired.

[0117] For multi-TRP operation with more than one TA, more than one TAG can be configured for a serving cell. For SpCell, 2 TAGs can be the primary TAG (PTAG). The question is which TAG of the serving cell’s TAT is considered as expired when the maximum uplink transmission timing difference between TAGs of the MAC entity is exceeded.

[0118] In this disclosure, an embodiment for handling TA and TAT is provided.

[0119] In one embodiment, when the MAC entity stops uplink transmission for a SCell due to the fact that the maximum uplink transmission timing difference between TAGs of the MAC entity or the maximum uplink transmission timing difference between TAGs of any MAC entity of the UE is exceeded, the MAC entity considers all timeAlignmentTimer timeAlig nmentTimers associated with the SCell as expired.

[0120] In another embodiment, when the MAC entity stops uplink transmission associated with a STAG due to the fact that the maximum uplink transmission timing difference between TAGs of the MAC entity or the maximum uplink transmission timing difference between TAGs of any MAC entity of the UE is exceeded, the MAC entity considers all timeAlignmentTimer timeAlig nmentTimers associated with the STAG as expired.

[0121] In yet another embodiment, when the MAC entity stops uplink transmissions associated with a PTAG due to the fact that the maximum uplink transmission timing difference between 2 PTAGs of the same MAC entity of the UE is exceeded, the MAC entity considers the TAT of the TAGs of the SCells of the MAC entity to be expired. timeAlignmentTimer is considered expired.

[0122] In one embodiment, for each STAG, the TAT of the STAG is considered expired if the difference between the TA of the STAG and the TA of the first PTAG of the MAC entity or of any MAC entity is greater than the maximum uplink transmission timing difference.

[0123] In another embodiment, for each STAG, the TAT of the STAG is considered expired if the difference between the TA of the STAG and the TA of the second PTAG of the MAC entity or of any MAC entity is greater than the maximum uplink transmission timing difference.

[0124] In yet another embodiment, for each STAG, the TAT of the STAG is considered expired if the difference between the TA of the STAG and the TA of any of the PTAGs of the MAC entity or of any MAC entity is greater than the maximum uplink transmission timing difference.

[0125] In yet another embodiment, for each STAG, the TAT of the STAG is considered expired if the difference between the TA of the STAG and the TA of each PTAG of the MAC entity or of any MAC entity (e.g. N PTAGs if N TAGs are configured, N being an integer equal to or greater than 2) is greater than the maximum uplink transmission timing difference.

[0126] In yet another embodiment, in case two or more PTAGs are configured in the MAC entity, the TAT of the TAGs of the SCells of the MAC entity is considered expired if the difference between the TA of a PTAG and the TA of another PTAG of the MAC entity or of any MAC entity is greater than the maximum uplink transmission timing difference.

[0127] In yet another embodiment, in case two or more PTAGs are configured in the MAC entity, the TAT of the TAGs of the SCells of the MAC entity is considered expired if the difference between the TA of a PTAG of the MAC entity and the TA of another PTAG of another MAC entity is greater than the maximum uplink transmission timing difference.

[0128] In yet another embodiment, in case two or more PTAGs are configured in the MAC entity, the TAT of the PTAG of the MAC entity is considered expired if the difference between the TA of a PTAG and the TA of another PTAG of the MAC entity or of any MAC entity is greater than the maximum uplink transmission timing difference.

[0129] In yet another embodiment, in case two or more PTAGs are configured in a MAC entity, the TAT of a PTAG of the MAC entity is considered expired if the difference between the TA of the PTAG and the TA of another PTAG of another MAC entity is greater than the maximum uplink transmission timing difference.

[0130] In yet another embodiment, in case two PTAGs are configured in a MAC entity, for a PTAG, the TAT of the second PTAG is considered expired if the difference between the TA of the first PTAG and the TA of the second PTAG of the MAC entity is greater than the maximum uplink transmission timing difference.

[0131] In yet another embodiment, in case two PTAGs are configured in a MAC entity, for a PTAG, the TAT of the first PTAG is considered expired if the difference between the TA of the first PTAG and the TA of the second PTAG of the MAC entity is greater than the maximum uplink transmission timing difference.

[0132] In yet another embodiment, in case two PTAGs are configured in a MAC entity, for a PTAG, the TAT of the PTAG configured with tag-Id2 is considered expired if the difference between the TA of the first PTAG and the TA of the second PTAG of the MAC entity is greater than the maximum uplink transmission timing difference.

[0133] In yet another embodiment, in case two PTAGs are configured in a MAC entity, for a PTAG, the TAT of the first PTAG configured with tag-Id is considered expired if the difference between the TA of the first PTAG and the TA of the second PTAG of the MAC entity is greater than the maximum uplink transmission timing difference.

[0134] In yet another embodiment, in case two PTAGs are configured in a MAC entity, for a PTAG, the TAT of both the PTAGs are considered expired if the difference between the TA of the first PTAG and the TA of the second PTAG of the MAC entity is greater than the maximum uplink transmission timing difference.

[0135] In yet another embodiment, in case more than two PTAGs are configured in a MAC entity, for a PTAG, the TAT of the kth PTAG is considered expired if the difference between the TA of the first PTAG and the TA of the kth PTAG (e.g., k is an integer greater than 1) of the MAC entity is greater than the maximum uplink transmission timing difference.

[0136] If any of the above cases occur, the UE stops any UL transmission.

[0137] The absolute timing advance command MAC CE includes TA in TS 38.213 for controlling the amount of timing adjustment that the MAC entity can apply.

[0138] In one embodiment, if 2 TAGs are configured for a serving cell (e.g., SpCell), one reserved bit (renamed as TAG indication field) can be used to indicate one of the 2 TAGs (i.e., first TAG or second TAG). In another embodiment, if 2 or more TAGs are configured for a serving cell, 2 reserved bits (renamed as TAG ID field) can be used to indicate the TAG ID of the TAGs. If only one TAG is configured for a serving cell (i.e., SpCell), there is a reserved bit instead of the TAG indication / ID field.

[0139] Table 2 shows the MAC entity.

[0140] Table 2. MAC entity

[0141] A serving cell in NTN can provide a configuration for satellite handover without PCI change, which can be broadcasted in system information or sent to UE via dedicated signaling (e.g., RRC reconfiguration message).

[0142] When the UE performs RRC resume, the 2 TAG configuration for multi-TRP operation can be released upon initiation of RRC resume. In one embodiment, upon initiation of the RRC resume procedure, the UE releases the configuration of 2 TAGs, which can include tag-Id2, and / or the mapping between TAG ID and TAG index (i.e., first TAG / second TAG) within a cell, and / or the second N_TAoffset parameter, and / or the list of RACH configuration of additional PCIs associated with the serving cell. If the mapping is configured in the TAG configuration and / or joint / DL / UL TCI state configuration, the mapping is released.

[0143] When the UE performs RRC reestablishment, the 2 TAG configuration for multi-TRP operation can be released upon initiation of RRC reestablishment. In one embodiment, upon initiation of the RRC reestablishment procedure, if the UE is not configured with attemptCondReconfig , the UE releases the configuration of 2 TAGs, which can include tag-Id2, and / or the mapping between TAG ID and TAG index (i.e., first TAG / second TAG) within a cell, and / or the second N_TAoffset parameter, and / or the list of RACH configuration of additional PCIs associated with the serving cell. If the mapping is configured in the TAG configuration and / or joint / DL / UL TCI state configuration, the mapping is released.

[0144] In another embodiment, when the UE performs RRC setup and / or RRC resume and / or RRC reestablishment, if the configuration of 2 TAGs and / or the configuration of multi-TRP operation with 2 TAs is configured / stored / resumed / applied by the UE, the UE applies the TAG associated with the tag-Id (i.e., mandatory parameter in Rel-15) included in the serving cell configuration and / or starts the associated time alignment timer.

[0145] In one example, when performing RRC resume or RRC reestablishment, the UE can perform operations as shown in Table 3.

[0146] Table 3.

[0147] In one embodiment, the SSB information for the target satellite for satellite handover can be included in the configuration. The SSB information can include the SSB index broadcasted by the target satellite and / or the SSB index broadcasted by the serving satellite and / or the associated timing information (e.g., the start time when the SSB from the target satellite becomes available). The SSB information can include the parameter ssb-PositionsInBurst, which indicates the time-domain positions of the transmitted SS blocks in the SS burst.

[0148] If the UE supports satellite handover with no PCI change, after initiating the satellite handover or after the start time of the target satellite becomes available, the UE applies the SSB information when performing DL and / or UL synchronization with the target satellite. In an example, the UE searches for the SSB broadcasted by the target satellite and performs DL synchronization, and initiates a RACH procedure or a RACH-less procedure. The UE selects from the indicated SSBs for PRACH preamble transmission.

[0149] In another embodiment, if the UE supports satellite handover with no PCI change, after initiating the satellite handover or after the start time of the target satellite becomes available, the UE acquires the MIB and / or SIB1 of the serving cell, reads the SSB information of the target satellite included in the SIB1 and applies the SSB information for DL and / or UL synchronization with the target satellite. In an example, the UE searches for the SSB broadcasted by the target satellite and performs DL synchronization, and initiates a RACH procedure or a RACH-less procedure.

[0150] In one embodiment, the configuration for satellite handover without PCI change can include a time window and / or SSB information of the time window for satellite handover. The time window can indicate a duration that both source satellite and target satellite are available to serve the cell. The SSB information can indicate SSB indices broadcasted by the source satellite and / or SSB indices broadcasted by the target satellite within the time window. After initiating satellite exchange or after the start time of the time window, the UE applies the SSB information when performing DL and / or UL synchronization with the target satellite. In an example, the UE searches for SSBs broadcasted by the target satellite and performs DL synchronization, and initiates a RACH procedure or a RACH-less procedure.

[0151] In another embodiment, information about SSBs to be broadcasted by the source satellite during the indicated duration and information about SSBs that can be broadcasted by the target satellite during the indicated duration can be signaled in system information (e.g., SIB19). In one example, the information includes SSB indices, which can be a subset of SSBs initially broadcasted before the handover. The SSB indices of the subset SSBs can be indicated by one or more bitmaps, where a bit set to zero means that there is no corresponding SSB in the satellite, and a bit set to 1 means that the corresponding SSB is broadcasted by the satellite. If the SSB indices associated with the source satellite are signaled, the UE measures / searches the indicated SSBs from the source satellite during the indicated duration. If the SSB indices associated with the target satellite are signaled, the UE measures / searches / synchronizes to the indicated SSBs from the target satellite during the indicated duration. If the SSB indices associated with the target satellite are signaled, the UE applies the indicated SSBs to perform a random access procedure to the target satellite. The UE selects from the indicated SSBs for PRACH preamble transmission.

[0152] The duration can refer to a time period that both the source satellite and the target satellite serve the cell. In one example, the duration can be indicated by a start time and an end time, the start time can be indicated by t-Start, and the end time can be indicated by t-Service. In another example, the duration can be indicated by a duration and a reference time, such that the start time can be derived based on the reference time and the duration. If the duration is positive, the start time is before the reference time, and if the duration is negative, the reference time is the start time.

[0153] After the duration, the UE releases the configuration of the SSB indices for satellite handover. The UE can start searching all SSBs to measure / search / synchronize to the serving cell.

[0154] In one embodiment, the reference / start / end / service stop time is indicated by absolute time. The time can be in the format of UTC time, indicating time in multiples of 10 ms after 00:00:00 on the Gregorian calendar date of 1 January 1900 (midnight between Sunday 31 December 1899 and Monday 1 January 1900). The UE considers the reference point of the indicated time at the UL synchronization reference time and considers the propagation delay between the UE and the reference point when determining the reference / start / end / service stop time at the UE.

[0155] In the no RACH procedure in satellite handover without PCI change, after the start time of the satellite handover, the UE applies the SSB information to start DL synchronization with the target satellite, starts RRC timer T430 when performing UL synchronization, indicates T430 start to lower layers (e.g., MAC entity), and starts TAT of PTAG of the MAC entity after the MAC entity receives the upper layer indication.

[0156] In the no RACH procedure in satellite handover without PCI change, after the start time of the satellite handover, the UE applies the SSB information to start DL synchronization with the target satellite, starts RRC timer T430 when performing UL synchronization, indicates T430 start to lower layers (e.g., MAC entity), and starts TAT of PTAG of the MAC entity after the MAC entity receives the upper layer indication.

[0157] In one other embodiment, as shown in Figure 13 The (enhanced) unified TCI state activation / deactivation MAC CE is identified by a MAC subheader with eLCID as specified in 3GPP standard specifications. The MAC CE includes one or more of the following fields.

[0158] In one example, the MAC CE includes an M / S field. This field indicates whether the TCI state ID indicated in this MAC CE is for a single TRP or for two TRPs. The field is set to 0 to indicate that the TCI state ID is for a single TRP. The field is set to 1 to indicate that the TCI state ID is for two TRPs (i.e., there is a TCI state ID for the second TRP).

[0159] In one example, the MAC CE includes a CORESET pool ID field. When the M / S field is set to 0, this field indicates that the TCI state ID indicated in this MAC CE is specific to the ControlResourceSet with CORESET pool ID as specified in TS 38.331 configured. When the M / S field is set to 1, this field is considered as a reserved bit. The field being set to 1 indicates that the TCI state ID indicated in this MAC CE is specific to CORESET pool ID 1, otherwise, the TCI state ID indicated in this MAC CE is specific to CORESET pool ID 0. The MAC entity shall ignore this field if none of the CORESETs in the corresponding BWP is configured with coresetPoolIndex , or if no more than one coresetPoolIndex is configured for any CORESET in the corresponding BWP, or if the value is only zero for any CORESET in the corresponding BWP. The CORESET pool ID field shall be ignored when the serving cell in the MAC CE is configured in a list of cells containing more than one serving cell upon reception of the MAC CE. coresetPoolIndex

[0160] In one example, the MAC CE includes a serving cell ID field. This field indicates the identity of the serving cell to which the MAC CE applies. The length of the field is 5 bits. If the indicated serving cell is configured as part of simultaneousU-TCI-UpdateList1 , simultaneousU-TCI-UpdateList2 , simultaneousU- TCI-UpdateList3 or simultaneousU-TCI-UpdateList4 as specified in TS 38.331, this MAC CE applies to all serving cells in the set simultaneousU-TCI-UpdateList1 , simultaneousU-TCI-UpdateList2 , simultaneousU- TCI-UpdateList3 or simultaneousU-TCI-UpdateList4 respectively.

[0161] In one example, the MAC CE includes a DL BWP ID field. This field indicates the DL BWP to which the MAC CE applies as the codepoint of the DCI bandwidth part indicator field as specified in TS 38.212. The length of the BWP ID field is 2 bits.

[0162] In one example, the MAC CE includes a UL BWP ID field. This field indicates the UL BWP to which the MAC CE applies as the codepoint of the DCI bandwidth part indicator field as specified in TS 38.212. If the value of unifiedTCI-StateType in the serving cell indicated by the serving cell ID is , unified ​If the field is not present, the field is considered as reserved bits. The length of the BWP ID field is 2 bits.

[0163] In one example, the MAC CE includes a C i-k field. The field indicates whether there is a TCI state ID for the i-th TCI codepoint for the k-th TRP corresponding to the CORESET pool ID k-1, where k = 1, 2 and i = 1, …, 8. The field is set to 1 indicates that there is a TCI state ID for the i-th TCI codepoint for the k-th TRP; the field is set to 0 indicates that there is no TCI state ID for the i-th TCI codepoint for the k-th TRP. If the M / S field is set to 0 and the CORESET pool ID is set to 0, there are eight octets for C i-1 and eight octets for P i-1 ; if the M / S field is set to 0 and the CORESET pool ID is set to 1, there are no eight octets for C i-2 and no eight octets for P i-2 ; if the M / S field is set to 1, there are all eight octets for C i-1 and P i-1 . i-2 i-2 i-k i-1

[0164] In one example, the MAC CE includes a P i-k field. The field indicates for the k-th TRP corresponding to the CORESET pool ID k-1, if C i-k is set to 1, it indicates whether the i-th TCI codepoint is with two TCI state IDs or a single TCI state ID. If the unified TCI state is configured by upper layer parameter as unified , the field is not present. If the unified TCI state is configured by upper layer parameter as separate , the field is present. If C i-k is set to 0, P i-k is considered as reserved bits. If C i-k is set to 1, and if P i-k field is set to 0, it indicates that one TCI state ID is indicated for the i-th TCI codepoint for the k-th TRP. If C i-k is set to 1, and if P i-k field is set to 1, it indicates that two TCI state IDs are indicated for the i-th TCI codepoint for the k-th TRP.

[0165] ​​​​In one example, the MAC CE includes a D / U field. This field indicates whether the TCI state ID in the same octet is for joint / downlink or uplink TCI state. If this field is set to 1, the TCI state ID in the same octet is for joint / downlink. If this field is set to 0, the TCI state ID in the same octet is for uplink.

[0166] In one example, the MAC CE includes a TCI state ID field. This field indicates the TCI state identified by the TCI state ID as specified in TS 38.331. If D / U is set to 1, a 7-bit length TCI state ID as specified in TS 38.331 is used, i.e., TCI-StateId TCI-StateId If D / U is set to 0, the most significant bit of the TCI state ID is considered as a reserved bit and the remaining 6 bits indicate the TCI state ID as specified in TS 38.331. UL-TCIState-Id Figure 4 Figure 6 For the examples shown in

[0167] The maximum number of activated TCI states is 32.

[0168] In one example, the MAC CE includes an R field. This field includes a reserved bit set to 0.

[0169] In one further embodiment, as shown in Figure 14 , the (enhanced) unified TCI state activation / deactivation MAC CE is identified by a MAC subheader with eLCID as specified in 3GPP standard specifications. The MAC CE includes a variable size field consisting of one or more of the following fields.

[0170] In one example, the MAC CE includes a serving cell ID field. This field indicates the identity of the serving cell to which the MAC CE applies. The length of the field is 5 bits. If the indicated serving cell is configured as a joint downlink TCI state as specified in TS 38.331, simultaneousU-TCI-UpdateList1 simultaneousU-TCI-UpdateList2 simultaneousU- TCI-UpdateList3 or simultaneousU-TCI-UpdateList4 ​​​​​If the MAC CE is part of a MAC CE that applies to all serving cells in the set simultaneousU-TCI-UpdateList1 , simultaneousU-TCI-UpdateList2 , simultaneousU- TCI-UpdateList3 or simultaneousU-TCI-UpdateList4 , then the MAC CE applies to all serving cells in the set

[0171] In one example, the MAC CE includes a DL BWP ID field. This field indicates the DL BWP to which the MAC CE applies as a codepoint of the DCI bandwidth part indicator field as specified in TS 38.212. The length of the BWP ID field is 2 bits.

[0172] In one example, the MAC CE includes a UL BWP ID field. This field indicates the UL BWP to which the MAC CE applies as a codepoint of the DCI bandwidth part indicator field as specified in TS 38.212. If the value unifiedTCI-StateType of is unified for a serving cell indicated by the serving cell ID, then this field is considered as a reserved bit. The length of the BWP ID field is 2 bits.

[0173] In one example, the MAC CE includes a C i-k field. This field indicates whether there is a TCI state ID for the i-th TCI codepoint for the k-th TRP corresponding to the CORESET pool ID k-1, where k = 1, 2 and i = 1, …, 8. The field is set to 1 to indicate that there is a TCI state ID for the i-th TCI codepoint for the k-th TRP; the field is set to 0 to indicate that there is no TCI state ID for the i-th TCI codepoint for the k-th TRP.

[0174] In one example, the MAC CE includes a P i-k field. This field indicates for the k-th TRP corresponding to the CORESET pool ID k-1, whether the i-th TCI codepoint is with two TCI state IDs or a single TCI state ID if C i-k is set to 1. If the unified TCI state is configured by upper layer parameter to be unified , then this field is not present. If the unified TCI state is configured by upper layer parameter to be separate , then this field is present. If C i-k is set to 0, then P i-k (if present) is considered as a reserved bit. If C i-k is set to 1, and if P i-k field is set to 0, then this indicates that one TCI state ID is indicated for the i-th TCI codepoint for the k-th TRP. If Ci-k is set to 1, and if P i-k If the field is set to 1, this indicates that the i-th TCI state ID for the k-th TRP is indicated.

[0175] In one example, the MAC CE includes a D / U field. This field indicates whether the TCI state IDs in the same octet are for joint / downlink or uplink TCI states. If this field is set to 1, the TCI state IDs in the same octet are for joint / downlink. If this field is set to 0, the TCI state IDs in the same octet are for uplink.

[0176] In one example, the MAC CE includes a TCI state ID field. This field indicates the TCI state identified by the TCI state ID as specified in TS 38.331 TCI-StateId If D / U is set to 1, a 7-bit length TCI state ID as specified in TS 38.331 is used, i.e., TCI-StateId If D / U is set to 0, the most significant bit of the TCI state ID is considered as a reserved bit and the remaining 6 bits indicate the UL-TCIState-Id In one example, the TCI state IDs for one TRP are indicated in the first N octets in ascending order of i. The TCI state IDs for other TRPs are indicated in the subsequent M octets in ascending order of i. In another example, the TCI state IDs are indicated in ascending order of codepoint index I, where for each codepoint, the TCI state ID for the first TRP is followed by the TCI state ID for another TRP. The maximum number of activated TCI states for each TRP is 16.

[0177] The maximum number of activated TCI states is 32; In one example, the MAC CE includes an R field. This includes a reserved bit set to 0.

[0178] Figure 15 A flowchart of a UE method 1500 for a MAC CE for multi-TRP operation in a wireless communication system according to embodiments of the present disclosure is shown. The method 1500 can be performed by a UE (e.g., as shown in Figure 1 The method 15 shown is for illustration only. Figure 15 Embodiments of the method 15 shown are for illustration only. Figure 15 The one or more components shown can be implemented in specialized circuitry configured for performing the recited functions, or one or more components can be implemented by one or more processors executing instructions to perform the recited functions.

[0179] As Figure 15As shown, the method 1500 begins at step 1502. In step 1502, the UE receives, from a BS belonging to a serving cell, a first MAC PDU including a first MAC subheader having a first eLCID and a first MAC CE.

[0180] In step 1504, the UE identifies, based on the first eLCID, an enhanced unified TCI state activation / deactivation MAC CE for joint or separate TCI states, the MAC CE including a bitmap of TCI state ID present indications and TCI state IDs, wherein a bit in the bitmap of TCI state ID present indications indicates whether a TCI state for a TRP associated with a codepoint of a DCI TCI field is present in a corresponding MAC CE, and wherein a maximum number of TCI state IDs activated is 32.

[0181] In step 1506, the UE indicates, to a lower layer, information associated with the corresponding MAC CE.

[0182] In one embodiment, the UE receives a second MAC PDU including a second MAC subheader having a second eLCID and a second MAC CE; identifies, based on the second eLCID, a unified TCI state activation / deactivation MAC CE; determines whether a CORESET pool ID is configured for a control resource set; and identifies, based on a determination that the CORESET pool ID is configured for the control resource set, that the unified TCI state activation / deactivation MAC CE includes the CORESET pool ID.

[0183] In such an embodiment, the CORESET pool ID indicates that a TCI state ID field is dedicated for a control resource set configured by the CORESET pool ID, and the TCI state ID field indicates a mapping between activated TCI states and codepoints of a DCI TCI.

[0184] In one embodiment, when no CORESET pool ID is configured for a control resource set, the UE identifies that the unified TCI state activation / deactivation MAC CE includes a reserved bit field.

[0185] In such an embodiment, the enhanced unified TCI state activation / deactivation MAC CE for joint or separate TCI states further includes at least one of a serving cell ID, a DL BWP ID, or a UL BWP ID.

[0186] In one embodiment, when the indicated serving cells are included in the list of serving cells, the UE applies the corresponding MAC CE to the entire serving cell identified in the list of serving cells, where the serving cell ID is five bits long and indicates the serving cell to which the corresponding MAC CE applies.

[0187] In such an embodiment, the DL BWP ID and the UL BWP ID indicate a DL BWP and a UL BWP, respectively, where the corresponding MAC CE applies as a codepoint of the DCI BWP indicator, and the DL BWP ID field is two bits long and the UL BWP ID field is two bits long.

[0188] In such an embodiment, a bit set to 1 in the bitmap of the indication of the TCI state ID indicates that there is a TCI state of a TRP associated with the codepoint, and set to 0 indicates that there is no TCI state of a TRP associated with the codepoint.

[0189] The above flowcharts illustrate example methods that can be implemented in accordance with the principles of the present disclosure, and various changes can be made to the methods illustrated in the flowcharts herein. For example, while shown as a series of steps, various steps in each figure could overlap, occur in parallel, occur in a different order, or occur multiple times. In another example, steps can be omitted or replaced by other steps.

[0190] While this disclosure has been described with example embodiments, the person of ordinary skill in the art can think of various changes and modifications. This disclosure is intended to encompass such changes and modifications as fall within the scope of the appended claims. None of the description in this application should be read in the limitations of any specific embodiment described. The scope of the patent subject matter is defined by the claims.

Claims

1. A method performed by a terminal in a wireless communication system, the method comprising: receiving, from a base station, a medium access control (MAC) control element (CE); identifying whether the MAC CE is associated with unified transmission configuration indicator (TCI) state activation or deactivation based on a MAC subheader with an extended logical channel identifier (eLCID) in the MAC CE; and in case that the MAC CE is associated with the unified TCI state activation or deactivation, receiving, from the base station, data based on the MAC CE associated with the unified TCI state activation or deactivation; wherein the MAC CE associated with the unified TCI state activation or deactivation includes information on an identifier associated with a bandwidth part (BWP), information on an identifier associated with a serving cell, information on an identifier associated with a TCI state, and information on an identifier associated with a control resource set (CORESET) pool. 2.The method of claim 1, further comprising: identifying whether the MAC CE is associated with enhanced unified TCI state activation or deactivation based on the MAC subheader with the eLCID in the MAC CE; and in case that the MAC CE is associated with the enhanced unified TCI state activation or deactivation, receiving, from the base station, data based on the MAC CE associated with the enhanced unified TCI state activation or deactivation. 3.The method of claim 2, wherein, the MAC CE associated with the enhanced unified TCI state activation or deactivation includes information associated with a presence of a TCI state. 4.The method of claim 2, wherein the MAC CE associated with the enhanced unified TCI state activation or deactivation includes the information on the identifier associated with the TCI state, wherein a maximum number of activated TCI states is 32. 5.A method performed by a base station in a wireless communication system, the method comprising: transmitting, to a terminal, a medium access control (MAC) control element (CE) associated with unified transmission configuration indicator (TCI) state activation or deactivation; and transmitting, to the terminal, data based on the MAC CE associated with the unified TCI state activation or deactivation; wherein the MAC CE associated with the unified TCI state activation or deactivation includes information on an identifier associated with a bandwidth part (BWP), information on an identifier associated with a serving cell, information on an identifier associated with a TCI state, and information on an identifier associated with a control resource set (CORESET) pool. 6.The method of claim 5, further comprising: transmitting, to the terminal, a MAC CE associated with enhanced unified TCI state activation or deactivation; and transmitting, to the terminal, data based on the MAC CE associated with the enhanced unified TCI state activation or deactivation. 7.The method of claim 6, wherein the MAC CE associated with the enhanced unified TCI state activation or deactivation includes information associated with a presence of a TCI state and the information about the identifier associated with the TCI state, wherein a maximum number of activated TCI states is 32. 8.A terminal in a wireless communication system, the terminal comprising: a transceiver; and at least one processor coupled with the transceiver and configured to: receive, from a base station, a medium access control (MAC) control element (CE), identify, based on a MAC subheader with an extended logical channel identifier (eLCID) in the MAC CE, whether the MAC CE is associated with a unified transmission configuration indicator (TCI) state activation or deactivation, and in a case that the MAC CE is associated with the unified TCI state activation or deactivation, receive, from the base station, data based on the MAC CE associated with the unified TCI state activation or deactivation, wherein the MAC CE associated with the unified TCI state activation or deactivation includes information about an identifier associated with a bandwidth part (BWP), information about an identifier associated with a serving cell, information about an identifier associated with a TCI state, and information about an identifier associated with a control resource set (CORESET) pool.

9. The terminal according to claim 8, wherein the at least one processor is configured to: identify, based on the MAC subheader with the eLCID in the MAC CE, whether the MAC CE is associated with an enhanced unified TCI state activation or deactivation, and in a case that the MAC CE is associated with the enhanced unified TCI state activation or deactivation, receive, from the base station, data based on the MAC CE associated with the enhanced unified TCI state activation or deactivation. 10.The terminal of claim 9, wherein the MAC CE associated with the enhanced unified TCI state activation or deactivation includes information associated with a presence of a TCI state. 11.The terminal of claim 9, wherein the MAC CE associated with the enhanced unified TCI state activation or deactivation includes the information about the identifier associated with the TCI state, wherein a maximum number of activated TCI states is 32. 12.A base station in a wireless communication system, the base station comprising: a transceiver; and at least one processor coupled with the transceiver and configured to: transmit, to a terminal, a medium access control (MAC) control element (CE) associated with a unified transmission configuration indicator (TCI) state activation or deactivation, and transmit, to the terminal, data based on the MAC CE associated with the unified TCI state activation or deactivation, wherein the MAC CE associated with the unified TCI state activation or deactivation includes information about an identifier associated with a bandwidth part, BWP, information about an identifier associated with a serving cell, information about an identifier associated with a TCI state, and information about an identifier associated with a control resource set, CORESET, pool.

13. The base station of claim 12, wherein, the at least one processor is configured to: transmit, to the terminal, a MAC CE associated with an enhanced unified TCI state activation or deactivation, and transmit, to the terminal, data based on the MAC CE associated with the enhanced unified TCI state activation or deactivation.

14. The base station of claim 13, wherein, the MAC CE associated with the enhanced unified TCI state activation or deactivation includes information associated with a presence of a TCI state.

15. The base station of claim 13, wherein, the MAC CE associated with the enhanced unified TCI state activation or deactivation includes the information about the identifier associated with the TCI state, wherein a maximum number of activated TCI states is 32.

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