Method and apparatus for clustering and power allocation for multi-TRP joint transmission in wireless communication system

Abstract

The disclosure relates to a 5G or 6G communication system for supporting a higher data transmission rate. A method and device for clustering and power allocation for multi-TRP transmission. A method comprises providing multi-tier clustering to enable joint transmission across multiple transmit-receive-point (TRP) sets. The method includes utilizing one or more 2nd-tier clusters located in an intersection of one or more adjacent 1st-tier clusters to mitigate interference at cluster edges, and providing dynamic cluster selection to enable the joint transmission across the multiple TRPs while mitigating interference at cluster edges based on selecting a tailored cluster with respect to a signal power of each user equipment (UE) within the 1st-tier clusters.

Description

METHOD AND APPARATUS FOR CLUSTERING AND POWER ALLOCATION FOR MULTI-TRP JOINT TRANSMISSION IN WIRELESS COMMUNICATION SYSTEM

[0001] This disclosure relates generally to wireless communication, and more specifically to clustering and power allocation for multi-transmit-receive point (TRP) transmission in wireless communication system.

[0002] 5G mobile communication technologies define broad frequency bands such that high transmission rates and new services are possible, and can be implemented not only in “Sub 6GHz” bands such as 3.5GHz, but also in “Above 6GHz” bands referred to as mmWave including 28GHz and 39GHz. In addition, it has been considered to implement 6G mobile communication technologies (referred to as Beyond 5G systems) in terahertz (THz) bands (for example, 95GHz to 3THz bands) in order to accomplish transmission rates fifty times faster than 5G mobile communication technologies and ultra-low latencies one-tenth of 5G mobile communication technologies.

[0003] At the beginning of the development of 5G mobile communication technologies, in order to support services and to satisfy performance requirements in connection with enhanced Mobile BroadBand (eMBB), Ultra Reliable Low Latency Communications (URLLC), and massive Machine-Type Communications (mMTC), there has been ongoing standardization regarding beamforming and massive MIMO for mitigating radio-wave path loss and increasing radio-wave transmission distances in mmWave, supporting numerologies (for example, operating multiple subcarrier spacings) for efficiently utilizing mmWave resources and dynamic operation of slot formats, initial access technologies for supporting multi-beam transmission and broadbands, definition and operation of BWP (BandWidth Part), new channel coding methods such as a LDPC (Low Density Parity Check) code for large amount of data transmission and a polar code for highly reliable transmission of control information, L2 pre-processing, and network slicing for providing a dedicated network specialized to a specific service.

[0004] Currently, there are ongoing discussions regarding improvement and performance enhancement of initial 5G mobile communication technologies in view of services to be supported by 5G mobile communication technologies, and there has been physical layer standardization regarding technologies such as V2X (Vehicle-to-everything) for aiding driving determination by autonomous vehicles based on information regarding positions and states of vehicles transmitted by the vehicles and for enhancing user convenience, NR-U (New Radio Unlicensed) aimed at system operations conforming to various regulation-related requirements in unlicensed bands, NR UE Power Saving, Non-Terrestrial Network (NTN) which is UE-satellite direct communication for providing coverage in an area in which communication with terrestrial networks is unavailable, and positioning.

[0005] Moreover, there has been ongoing standardization in air interface architecture / protocol regarding technologies such as Industrial Internet of Things (IIoT) for supporting new services through interworking and convergence with other industries, IAB (Integrated Access and Backhaul) for providing a node for network service area expansion by supporting a wireless backhaul link and an access link in an integrated manner, mobility enhancement including conditional handover and DAPS (Dual Active Protocol Stack) handover, and two-step random access for simplifying random access procedures (2-step RACH for NR). There also has been ongoing standardization in system architecture / service regarding a 5G baseline architecture (for example, service based architecture or service based interface) for combining Network Functions Virtualization (NFV) and Software-Defined Networking (SDN) technologies, and Mobile Edge Computing (MEC) for receiving services based on UE positions.

[0006] As 5G mobile communication systems are commercialized, connected devices that have been exponentially increasing will be connected to communication networks, and it is accordingly expected that enhanced functions and performances of 5G mobile communication systems and integrated operations of connected devices will be necessary. To this end, new research is scheduled in connection with eXtended Reality (XR) for efficiently supporting AR (Augmented Reality), VR (Virtual Reality), MR (Mixed Reality) and the like, 5G performance improvement and complexity reduction by utilizing Artificial Intelligence (AI) and Machine Learning (ML), AI service support, metaverse service support, and drone communication.

[0007] Furthermore, such development of 5G mobile communication systems will serve as a basis for developing not only new waveforms for providing coverage in terahertz bands of 6G mobile communication technologies, multi-antenna transmission technologies such as Full Dimensional MIMO (FD-MIMO), array antennas and large-scale antennas, metamaterial-based lenses and antennas for improving coverage of terahertz band signals, high-dimensional space multiplexing technology using OAM (Orbital Angular Momentum), and RIS (Reconfigurable Intelligent Surface), but also full-duplex technology for increasing frequency efficiency of 6G mobile communication technologies and improving system networks, AI-based communication technology 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 technology for implementing services at levels of complexity exceeding the limit of UE operation capability by utilizing ultra-high-performance communication and computing resources.

[0008] The present disclosure provides method and apparatus for method and apparatus for clustering and power allocation for multi-TRP joint transmission in wireless communication system.

[0009] According to an aspect of an exemplary embodiment, there is provided method and apparatus for clustering and power allocation for multi-TRP joint transmission in wireless communication system.

[0010] Aspects of the present disclosure provide efficient communication methods in a wireless communication system.

[0011] 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 reference numerals represent like parts:

[0012] FIG. 1 illustrates an example wireless network according to embodiments of the present disclosure;

[0013] FIG. 2 illustrates an example gNodeB (gNB) according to embodiments of the present disclosure;

[0014] FIG. 3 illustrates an example user equipment (UE) according to embodiments of the present disclosure;

[0015] FIG. 4 illustrates an example of horizontal TRP expansion according to embodiments of the present disclosure;

[0016] FIG. 5 illustrates an example of back-to-back TRP configuration in a bidirectional-cuboid-array (BCA) according to embodiments of the present disclosure;

[0017] FIG. 6 illustrates an example of 3D-massive multiple input multiple output (MMU) in a base station site according to embodiments of the present disclosure;

[0018] FIG. 7 illustrates an example of 3D-MMU tier-1 clustering for a 2-ring hexagonal cell layout according to embodiments of the present disclosure;

[0019] FIG. 8 illustrates an example of cluster-edges of tier-1 clusters according to embodiments of the present disclosure;

[0020] FIG. 9 illustrates an example of a 1-ring hexagonal cell layout covered by both tier-1 clustering and tier-2 clustering according to embodiments of the present disclosure;

[0021] FIGS. 10A and 10B illustrate an example of a UE being offloaded from a tier-1 cluster to a tier-2 cluster according to embodiments of the present disclosure;

[0022] FIG. 11 illustrates an example of a geometric distribution of UEs according to embodiments of the present disclosure;

[0023] FIG. 12 illustrates an example of dynamic tier-1 cluster selection according to embodiments of the present disclosure;

[0024] FIG. 13 illustrates an example of a geometric distribution for UEs connected to a particular cell according to embodiments of the present disclosure; and

[0025] FIG. 14 illustrates an example method for clustering and power allocation for multi-TRP transmission according to embodiments of the present disclosure.

[0026] FIG. 15 is a block diagram of a terminal or user equipment (UE) according to an embodiment of the disclosure.

[0027] FIG. 16 is a block diagram of a base station (BS) according to an embodiment of the disclosure.

[0028] FIG. 17 is a block diagram of a network entity according to an embodiment of the disclosure.

[0029] Hereinafter, embodiments of the disclosure will be described in detail with reference to the accompanying drawings.

[0030] In describing the embodiments, descriptions related to technical contents well-known in the art and not associated directly with the disclosure will be omitted. Such an omission of unnecessary descriptions is intended to prevent obscuring of the main idea of the disclosure and more clearly transfer the main idea.

[0031] For the same reason, in the accompanying drawings, some elements may be exaggerated, omitted, or schematically illustrated. Further, the size of each element does not completely reflect the actual size. In the drawings, identical or corresponding elements are provided with identical reference numerals or different reference numerals.

[0032] The advantages and features of the disclosure and ways to achieve them will be apparent by making reference to embodiments as described below in detail in conjunction with the accompanying drawings. However, the disclosure is not limited to the embodiments set forth below, but may be implemented in various different forms. The following embodiments are provided only to completely disclose the disclosure and inform those skilled in the art of the scope of the disclosure, and the disclosure is defined only by the scope of the appended claims. Throughout the specification, the same or like reference numerals designate the same or like elements. Furthermore, in describing the disclosure, a detailed description of known functions or constitution incorporated herein will be omitted in the case that it is determined that the description may make the subject matter of the disclosure unnecessarily unclear. The terms which will be described below are terms defined in consideration of the functions in the disclosure, and may be different according to users, intentions of the operators, or customs. Therefore, the definitions of the terms should be made based on the contents throughout the specification.

[0033] Herein, it will be understood that each block of the flowchart illustrations, and combinations of blocks in the flowchart illustrations, may be performed based on computer program instructions. These computer program instructions may be loaded collectively onto at least one processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which perform through any one of, or in any combination of, the at least one processor of the computer or other programmable data processing apparatus, create means for performing the functions specified in the flowchart block(s). These computer program instructions may also be stored in a non-transitory computer usable or computer-readable memory that may direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer usable or computer-readable memory produce an article of manufacture including instruction means that perform the function specified in the flowchart block(s). The computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable data processing apparatus to produce a computer executed process such that the instructions that perform on the computer or other programmable data processing apparatus provide steps for executing the functions specified in the flowchart block(s).

[0034] Further, each block may represent a module, segment, or portion of code, which includes one or more executable instructions for executing the specified logical function(s). It should also be noted that in some alternative implementations, the functions noted in the blocks may occur out of the order. For example, two blocks(or functions) shown in succession may in fact be performed substantially concurrently or the blocks may sometimes be performed in the reverse order, depending upon the functionality involved.

[0035] As used in embodiments of the disclosure, a “~unit” may refer to a software element or a hardware element, such as a field programmable gate array (FPGA) or an application specific integrated circuit (ASIC), which performs a predetermined function. However, the term including the word “~unit” does not always have a meaning limited to software or hardware. The “~unit” may be constructed either to be stored in an addressable storage medium or to execute one or more processors. Therefore, the “~unit” includes, for example, software elements, object-oriented software elements, components such as class elements and task elements, processes, functions, properties, procedures, sub-routines, segments of a program code, drivers, firmware, micro-codes, circuits, data, database, data structures, tables, arrays, and parameters. The components and functions provided by the “~unit” may be either combined into a smaller number of components and a “~unit,” or divided into additional components and a “~unit.” Moreover, the components and “~units” may be implemented to reproduce one or more central processing units (CPUs) within a device or a security multimedia card. Further, in the embodiments, the “~unit” may include one or more processors.

[0036] It should be appreciated that the blocks in each flowchart and combinations of the flowcharts may be performed by one or more computer programs which include instructions. The entirety of the one or more computer programs may be stored in a single memory device or the one or more computer programs may be divided with different portions stored in different multiple memory devices.

[0037] Any of the functions or operations described herein can be processed by one processor or a combination of processors. The one processor or the combination of processors is circuitry performing processing and includes circuitry like an application processor (AP, e.g. a CPU), a communication processor (CP, e.g., a modem), a graphics processing unit (GPU), a neural processing unit (NPU) (e.g., an artificial intelligence (AI) chip), a Wi-Fi chip, a Bluetooth® chip, a global positioning system (GPS) chip, a near field communication (NFC) chip, connectivity chips, a sensor controller, a touch controller, a finger-print sensor controller, a display driver integrated circuit (IC), an audio CODEC chip, a universal serial bus (USB) controller, a camera controller, an image processing IC, a microprocessor unit (MPU), a system on chip (SoC), an IC, or the like.

[0038] It will be appreciated that various embodiments of the disclosure according to the claims and description in the specification can be realized in the form of hardware, software or a combination of hardware and software.

[0039] Any such software may be stored in non-transitory computer readable storage media. The non-transitory computer readable storage media store one or more computer programs (software modules), the one or more computer programs include computer-executable instructions that, when executed by one or more processors of an electronic device individually or collectively, cause the electronic device to perform a method of the disclosure.

[0040] Any such software may be stored in the form of volatile or non-volatile storage such as, for example, a storage device like read only memory (ROM), whether erasable or rewritable or not, or in the form of memory such as, for example, random access memory (RAM), memory chips, device or integrated circuits or on an optically or magnetically readable medium such as, for example, a compact disk (CD), digital versatile disc (DVD), magnetic disk or magnetic tape or the like. It will be appreciated that the storage devices and storage media are various embodiments of non-transitory machine-readable storage that are suitable for storing a computer program or computer programs comprising instructions that, when executed, implement various embodiments of the disclosure. Accordingly, various embodiments of the present disclosure may provide a program comprising code for implementing apparatus or a method as claimed in any one of the claims of this specification and a non-transitory machine-readable storage storing such a program.

[0041] Hereinafter, the determination of priority between A and B in the present disclosure may refer to various actions such as selecting the one having a higher priority based on a predefined priority rule and performing an operation corresponding thereto, or omitting or dropping an operation corresponding to the one having a lower priority.

[0042] Hereinafter, "A or B" as described in the present disclosure may be understood as "A and / or B," which may include A, or B, or both A and B.

[0043] In addition, "at least one of A, B, and C" as described in the present disclosure may be understood to include A, or B, or C, or any combination of A, B, and C.

[0044] In addition, "at least one of A, B, or C" as described in the present disclosure may be understood to include A, or B, or C, or any combination of A, B, and C.

[0045] Furthermore, "A / B" as described in the present disclosure may be understood as "A and / or B," which may include A, or B, or both A and B.

[0046] Furthermore, "A, B" as described in the present disclosure may be understood as "A and / or B," which may include A, or B, or both A and B.

[0047] Furthermore, "A and B" as described in the present disclosure may be understood as "A and / or B," which may include A, or B, or both A and B.

[0048] Furthermore, “if condition A and condition B are satisfied,” as described in the present disclosure, may not be limited to a case where both condition A and condition B are satisfied, but may be understood to include a case where either condition A or condition B is individually satisfied, both condition A and condition B are satisfied, or one or more additional conditions are satisfied in combination.

[0049] Furthermore, throughout this disclosure, ordinal terms such as "first," "second," "third," etc., (and similar qualifiers) are used merely to distinguish between different instances, occurrences, configurations, messages, stages, or aspects of elements, operations, or information as described herein. Unless the context clearly dictates otherwise, the use of such ordinal terms does not itself require that the elements, operations, or information distinguished by these terms be structurally different, numerically distinct, or substantively dissimilar. For example, a "first signal" and a "second signal" may refer to instances of the same signal transmitted at different times or containing the same core information despite minor variations, or they may refer to signals with different content or characteristics, depending on the specific context. Similarly, a "first value" and a "second value" may represent the same magnitude but measured or applied in different circumstances, or they may represent different magnitudes. The interpretation should be guided by the specific technical context, function, and relationship described in the relevant portion of the specification and claims.

[0050] Furthermore, the terms “first ~”, “second ~”, etc., as described in the present disclosure with respect to various elements (e.g., information, objects, operation, sequences, or the like), should not limit those elements. These terms may only be intended to distinguish one element from another, and may not be intended to indicate a specific order. For example, a first element could be termed a second element, and, similarly, a second element could be termed a first element.

[0051] Furthermore, even if “first ~” and “second ~” are described in the present disclosure, it may be understood that element(s) referred to by “first ~” and “second ~” may be the same or different. For example, in case of element(s) being information, first information and second information may both be same information and, in some cases, are separate and different information.

[0052] In addition, the terms “if ~” and “in case that ~” as used in the disclosure or claims may be interpreted to include the meanings of “when (or upon) ~,” “in response to ~,” “based on ~,” or “according to ~,” and may be used interchangeably with these expressions. In addition, expressions other than those exemplified herein may also be used, as long as they have substantially the same meaning and do not impair the technical features of the present disclosure.

[0053] For example, the physical layer signaling may be referred to as Layer 1 (L1) signaling and may include downlink control information (DCI). In addition, the higher layer signaling may include a medium access control (MAC) control message, a radio resource control (RRC) signaling message, a non-access stratum (NAS) signaling message, or an application layer message. The RRC signaling message may be referred to as L3 (layer 3) signaling. It should be noted, however, that the higher layer signaling is not limited to the aforementioned examples.

[0054] In addition, the term "not perform" as used in the present disclosure or claims may, in context, be understood to mean that the corresponding step is omitted or skipped. Such a term may be replaced with other terms having the same or substantially equivalent meaning.

[0055] In addition, "transmitting a message including A and B" as described in the present disclosure, may be understood as encompassing both (i) transmitting A and B in a single message, and (ii) transmitting A and B separately via multiple messages (e.g., transmitting a first message including A and a second message including B). This interpretation may also apply to messages that include two or more items (e.g., A, B, C), transmitted either together or separately.

[0056] In addition, "transmitting a message including A and transmitting a message including B" may also be interpreted as transmitting a message including A and B in a single message.

[0057] In the specific embodiments of the present disclosure described below, terms or components included in the disclosure may be expressed in singular or plural form depending on the specific embodiments presented. However, such singular or plural expressions are selected appropriately for convenience of description, and the present disclosure is not limited to a singular or plural number of components. A component expressed in the plural form may be implemented as a single component, and a component expressed in the singular form may be implemented as multiple components.

[0058] The drawings or flowcharts described below illustrate exemplary methods that may be implemented according to the principles of the present disclosure, and various modifications may be made to the methods illustrated in the flowcharts of the present disclosure. For example, although illustrated as a series of steps, various steps in each drawing or flowchart may overlap, occur in parallel, occur in a different order, or be repeated. In other examples, any step may be omitted or replaced with another step.

[0059] The methods and apparatuses proposed in the embodiments of the present disclosure are not limited to each embodiment individually, but may also be applied in combination of all or some of the embodiments proposed in the disclosure. Therefore, the embodiments of the present disclosure may be modified and applied without significantly departing from the scope of the present disclosure, as would be understood by those skilled in the art.

[0060] In this case, even if certain wordings are described differently across embodiments, they may be used interchangeably or in substitution or in combination if their underlying concepts are equivalent. For example, for the same or equivalent concept, even if one embodiment uses the expression "A" and another embodiment uses the expression "B", such expressions may be understood interchangeably, in substitution, or in combination.

[0061] The terms used in the following description to refer to access nodes, network entities, messages, interfaces between network entities, various types of identification information, and the like, are provided merely for the convenience of explanation by way of example. Therefore, the present disclosure is not limited to the terms described below, and other terms having equivalent technical meanings may also be used. Such terms may also be interchangeable with terms defined in any 3rd generation partnership project (3GPP) technical specifications (TS) where appropriate.

[0062] Hereinafter, a base station is an entity that allocates resources to terminals, and may be at least one of a gNode B, an eNode B, a Node B, a base station (BS), a wireless access unit, a BS controller, or a node on a network.

[0063] Furthermore, the base station of the present disclosure may include a split architecture comprising a central unit (CU) and a distributed unit (DU). In this structure, the CU is configured to process the higher layers of the control and user planes, while the DU is configured to process lower-layer radio resource functions. The embodiments of the present disclosure may be equally applicable to 5G base station architectures in which such CU and DU functional splits are implemented.

[0064] A terminal may include a UE, a mobile station (MS), a cellular phone, a smartphone, a computer, or a multimedia system capable of performing communication functions.

[0065] In the disclosure, a downlink (DL) refers to a radio link through which a BS transmits a signal to a UE, and an uplink (UL) refers to a radio link through which a UE transmits a signal to a BS.

[0066] Furthermore, hereinafter, 5th generation (5G) mobile communication technologies (e.g., 5G new radio (NR)), 6th generation (6G) mobile communication technologies may be described by way of example, but the embodiments of the present disclosure may also be applied to other communication systems having similar technical backgrounds or channel types. For example, newly evolved mobile communication systems developed after 5G and 6G may be included. Furthermore, based on determinations by those skilled in the art, the embodiments of the present disclosure may also be applied to other communication systems (e.g., Wi-Fi systems) through some modifications without significantly departing from the scope of the present disclosure

[0067] In the following description, the terms physical channel and signal may be used interchangeably with data or control signal. For example, the term physical downlink shared channel (PDSCH) refers to a physical channel through which data is transmitted, but the term PDSCH may also be used to refer to the data itself. That is, in the present disclosure, the expression "transmit a physical channel" may be interpreted as being equivalent to the expression "transmit data or a signal via a physical channel."

[0068] Hereinafter, in the context of the present disclosure, higher layer signaling may refer to signaling corresponding to at least one or any combination of the following: master information block (MIB), system information block (SIB) or SIB M (M = 1, 2, ...), radio resource control (RRC), or medium access control (MAC) control element (CE), or a non-access stratum (NAS) signaling message, or an application layer message. The RRC signaling message may be referred to as L3 (layer 3) signaling.

[0069] In addition, L1 signaling may refer to signaling corresponding to at least one or any combination of signaling techniques using the at least one or any combination of the following physical layer channels or signaling: physical downlink control channel (PDCCH), downlink control information (DCI), user equipment (UE)-specific DCI, group-common DCI, common DCI, scheduling DCI (e.g., DCI used for scheduling downlink or uplink data), non-scheduling DCI (e.g., DCI not used for scheduling downlink or uplink data) physical uplink control channel (PUCCH), or uplink control information (UCI). The L1 signaling message may be referred to as a physical layer signaling.

[0070] Hereinafter, the expression that information is configured by the BS, as used in the present disclosure or claims, may, in context, be understood to mean that the terminal receives the corresponding information from the BS via a physical layer signaling or a higher layer signaling. Such an expression may be replaced with other terms having the same or substantially equivalent meaning.

[0071] This application claims priority under 35 U.S.C. § 119(e) to U.S. Provisional Patent Application No. 63 / 657,665 filed on June 7, 2024, which is hereby incorporated by reference in its entirety.

[0072] Hereinafter, the operational principle of the present disclosure will be described in detail with reference to the accompanying drawings.

[0073] 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. The 5G / NR communication system is considered to be implemented in higher frequency (mmWave) bands, e.g., 28 GHz or 60 GHz bands, so as to accomplish higher data rates or in lower frequency bands, such as 6 GHz, to enable robust coverage and mobility support. To decrease propagation loss of the radio waves and increase the transmission distance, the beamforming, massive multiple-input multiple-output (MIMO), full dimensional MIMO (FD-MIMO), array antenna, an analog beam forming, large scale antenna techniques are discussed in 5G / NR communication systems.

[0074] 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, device-to-device (D2D) communication, wireless backhaul, moving network, cooperative communication, coordinated multi-points (CoMP), reception-end interference cancelation and the like.

[0075] The discussion of 5G systems and frequency bands associated therewith is for reference as certain embodiments of the present disclosure may be implemented in 5G systems. However, the present disclosure is not limited to 5G systems, or the frequency bands associated therewith, and embodiments of the present disclosure may be utilized in connection with any frequency band. For example, aspects of the present disclosure may also be applied to deployment of 5G communication systems, 6G or even later releases which may use terahertz (THz) bands.

[0076] One way to further improve the performance of wireless communication systems is by increasing the number of available transceiver units (TXRUs). However, the two adjacent antennas are anticipated to maintain a critical spacing of at least a half-wavelength to overcome the space correlation at two neighboring elements with regard to small-scale fading in deployment environments. Due to the aforementioned factors, increasing the number of antenna elements may be practically infeasible, and may cause challenges in deployment.

[0077] Embodiments of the present disclosure provide methods and apparatuses for clustering and power allocation for multi-TRP transmission.

[0078] Other technical features may be readily apparent to one skilled in the art from the following figures, descriptions, and claims.

[0079] Before undertaking the DETAILED DESCRIPTION below, it may 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, whether or not those elements are in physical contact with one another. The terms “transmit”, “receive”, and “communicate”, as well as derivatives thereof, encompass both direct and indirect communication. The terms “include” and “comprise”, as well as 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, have a property of, have a relationship to or with, or the like. The term “controller” means any device, system or part thereof that controls at least one operation. Such a controller may be implemented in hardware or a combination of hardware and software and / or firmware. The functionality associated with any particular controller may 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 may be used, and only one item in the list may be needed. For example, “at least one of: A, B, and C” includes any of the following combinations: A, B, C, A and B, A and C, B and C, and A and B and C.

[0080] 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 and embodied in a computer readable medium. The terms “application” and “program” refer to one or more computer programs, software components, sets of instructions, procedures, functions, objects, classes, instances, related data, or a portion thereof adapted for implementation in a suitable computer readable program code. The phrase “computer readable program code” includes any type of computer code, including source code, object code, and executable code. The phrase “computer readable medium” includes any type of medium capable of being accessed by a computer, such as read only memory (ROM), random access memory (RAM), a hard disk drive, a compact disc (CD), a digital video disc (DVD), or any other type of memory. A “non-transitory” computer readable medium excludes wired, wireless, optical, or other communication links that transport transitory electrical or other signals. A non-transitory computer readable medium includes media where data can be permanently stored and media where data can be stored and later overwritten, such as a rewritable optical disc or an erasable memory device.

[0081] Definitions for other certain words and phrases are provided throughout this patent document. Those of ordinary skill in the art should understand that in many if not most instances, such definitions apply to prior as well as future uses of such defined words and phrases.

[0082] FIGS. 1 through 17, discussed below, and the various embodiments used to describe the principles of the present disclosure in this patent document are by way of illustration only and should not be construed in any way to limit the scope of the disclosure. Those skilled in the art will understand that the principles of the present disclosure may be implemented in any suitably arranged system or device.

[0083] The following documents and standards descriptions are hereby incorporated by reference into the present disclosure as if fully set forth herein: [1] 3GPP TS 36.211 v16.4.0, “E-UTRA, Physical channels and modulation”; [2] 3GPP TS 36.212 v16.4.0, “E-UTRA, Multiplexing and Channel coding”; [3] 3GPP TS 36.213 v16.4.0, “E-UTRA, Physical Layer Procedures”; [4] 3GPP TS 36.321 v16.3.0, “E-UTRA, Medium Access Control (MAC) protocol specification”;[5] 3GPP TS 36.331 v16.3.0, “E-UTRA, Radio Resource Control (RRC) Protocol Specification”; [6] 3GPP TS 38.211 v16.4.0, “NR, Physical channels and modulation;” [7] 3GPP TS 38.212 v16.4.0, “NR, Multiplexing and Channel coding”; [8] 3GPP TS 38.213 v16.4.0, “NR, Physical Layer Procedures for Control”; [9] 3GPP TS 38.214 v16.4.0, “NR, Physical Layer Procedures for Data”;

[0010] 3GPP TS 38.215 v16.4.0, “NR, Physical Layer Measurements”;

[0011] 3GPP TS 38.321 v16.3.0, “NR, Medium Access Control (MAC) protocol specification”; and

[0012] 3GPP TS 38.331 v16.3.1, “NR, Radio Resource Control (RRC) Protocol Specification”.

[0084] Embodiments of the present disclosure recognize that to increase the number of TXRUs, one may choose to horizontally append two TRPs. However, this expansion results in a significant increase in form factor size. To reduce massive MIMO unit (MMU) size, two layers of MMU antenna panels facing the same direction can be stacked; however, this may not be feasible due to the signal from the rear TRP attenuating significantly because of the ground-plane blockage issue from the front TRP. One may choose to reduce the antenna spacing to employ more ports in the same form factor size; however, this triggers loss in peak gain.

[0085] In addition, embodiments of the present disclosure recognize that a cellular network is based on the concept of dividing the geographic area into smaller regions or sectors, where user devices in each region are served by at least one TRP. Assuming each antenna element has the radiation power pattern with 65° half-power beamwidth, each gNodeB deploys three TRPs, each of which primarily handles a fixed 120° sector. This type of sectorization needs to be evolved such that flexible sectorization is available.

[0086] Further, embodiments of the present disclosure recognize that when dividing the cell layout with a finer granularity, a more diversified antenna angle orientation can be observed. While being compatible with other cell associations, a set of coordination TRPs, i.e., cluster, can be developed to jointly operate UEs. This results in both a higher signal power and a lower interference level; however, some UEs may suffer from inter-cluster interference. In addition, the precoders used from cooperating TRPs need to be normalized such that one or multiple system requirement are satisfied.

[0087] Accordingly, various embodiments of the present disclosure can provide methods and apparatuses for clustering and power allocation schemes of 3D-MMU architecture that enhances TXRU plurality without further increasing the horizontal dimension. To enable joint transmission across multi-TRPs while avoiding cell-edge problems, various embodiments of the present disclosure provide the notion of multi-tier clustering and dynamic cluster selection. Further, various embodiments of the present disclosure can provide power allocation schemes across multiple TRPs such that one or multiple significant constraints are satisfied. Further still, various embodiments of the present disclosure can provide multi-tier clustering to enable joint transmission across multiple TRPs while avoiding cell-edge problems by utilizing 2nd-tier clusters located in an intersection of adjacent 1st-tier clusters. In addition, various embodiments of the present disclosure can provide dynamic cluster selection to enable joint transmission across multiple TRPs while avoiding cell-edge problems by selecting a tailored cluster with respect to each UE’s signal power. Further still, various embodiments of the present disclosure can provide mechanisms for handling one or more power allocation schemes across multiple TRPs to satisfy one or more constraints.

[0088] FIGS. 1-3 below describe various embodiments implemented in wireless communications systems and with the use of orthogonal frequency division multiplexing (OFDM) or orthogonal frequency division multiple access (OFDMA) communication techniques. The descriptions of FIGS. 1-3 are not meant to imply physical or architectural limitations to the manner in which different embodiments may be implemented. Different embodiments of the present disclosure may be implemented in any suitably arranged communications system.

[0089] FIG. 1 illustrates an example wireless network according to embodiments of the present disclosure. The embodiment of the wireless network shown in FIG. 1 is for illustration only. Other embodiments of the wireless network 100 could be used without departing from the scope of this disclosure.

[0090] As shown in FIG. 1, 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.

[0091] The gNB 102 provides wireless broadband access to the network 130 for a first plurality of user equipments (UEs) within a coverage area 120 of the gNB 102. The first plurality of UEs includes a UE 111, which may be located in a small business; a UE 112, which may be located in an enterprise; a UE 113, which may be a WiFi hotspot; a UE 114, which may be located in a first residence; a UE 115, which may be located in a second residence; and a UE 116, which may 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 may 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.

[0092] 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 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 may provide wireless access in accordance with one or more wireless communication protocols, e.g., 5G / NR 3rd generation partnership project (3GPP) NR, long term evolution (LTE), LTE advanced (LTE-A), high speed packet access (HSPA), Wi-Fi 802.11a / b / g / n / ac, etc. For the sake of convenience, the terms “BS” and “TRP” are used interchangeably in this patent document to refer to network infrastructure components that provide wireless access to remote terminals. Also, depending on the network type, the term “user equipment” or “UE” can refer to any component such as “mobile station”, “subscriber station”, “remote terminal”, “wireless terminal”, “receive point”, or “user device”. For the sake of convenience, the terms “user equipment” and “UE” are used in this patent document to refer to remote wireless equipment that wirelessly accesses a BS, whether the UE is a mobile device (such as a mobile telephone or smartphone) or is normally considered a stationary device (such as a desktop computer or vending machine).

[0093] 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 should be clearly understood that the coverage areas associated with gNBs, such as the coverage areas 120 and 125, may 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.

[0094] Although FIG. 1 illustrates one example of a wireless network, various changes may be made to FIG. 1. For example, the wireless network could include any number of gNBs and any number of UEs in any suitable arrangement. Also, the gNB 101 could communicate directly with any number of UEs and provide those UEs with wireless broadband access to the network 130. Similarly, each gNB 102-103 could communicate directly with the network 130 and provide UEs with direct wireless broadband access to the network 130. Further, the 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.

[0095] FIG. 2 illustrates an example gNB 102 according to embodiments of the present disclosure. The embodiment of the gNB 102 illustrated in FIG. 2 is for illustration only, and the gNBs 101 and 103 of FIG. 1 could have the same or similar configuration. However, gNBs come in a wide variety of configurations, and FIG. 2 does not limit the scope of this disclosure to any particular implementation of a gNB.

[0096] As shown in FIG. 2, the gNB 102 includes multiple antennas 205a-205n, multiple transceivers 210a-210n, a controller / processor 225, a memory 230, and a backhaul or network interface 235.

[0097] 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 receive (RX) processing circuitry in the transceivers 210a-210n and / or controller / processor 225, which generates processed baseband signals by filtering, decoding, and / or digitizing the baseband or IF signals. The controller / processor 225 may further process the baseband signals.

[0098] Transmit (TX) processing circuitry in the transceivers 210a-210n and / or 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 up-convert the baseband or IF signals to RF signals that are transmitted via the antennas 205a-205n.

[0099] The controller / processor 225 can include one or more processors or other processing devices that control the overall operation of the gNB 102. For example, the controller / processor 225 could control the reception of UL channel signals and the transmission of DL channel signals by the transceivers 210a-210n in accordance with well-known principles. The controller / processor 225 could support additional functions as well, such as more advanced wireless communication functions. For instance, the controller / processor 225 could support beam forming or directional routing operations in which outgoing / incoming signals from / to multiple antennas 205a-205n are weighted differently to effectively steer the outgoing signals in a desired direction. Any of a wide variety of other functions could be supported in the gNB 102 by the controller / processor 225.

[0100] The controller / processor 225 or the transceivers 210a-210n may include circuitry and / or programming for facilitating clustering and power allocation for multi-TRP transmission. The controller / processor 225 is also capable of executing programs and other processes resident 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 an executing process.

[0101] 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. The interface 235 could support communications over any suitable wired or wireless connection(s). For example, when the gNB 102 is implemented as part of a cellular communication system (such as one supporting 5G / NR, LTE, or LTE-A), the interface 235 could allow the gNB 102 to communicate with other gNBs over a wired or wireless backhaul connection. When the gNB 102 is implemented as an access point, the interface 235 could allow the gNB 102 to communicate over a wired or wireless local area network or over a wired or wireless connection to a larger network (such as the Internet). The interface 235 includes any suitable structure supporting communications over a wired or wireless connection, such as an Ethernet or transceiver.

[0102] The memory 230 is coupled to the controller / processor 225. Part of the memory 230 could include a RAM, and another part of the memory 230 could include a Flash memory or other ROM.

[0103] Although FIG. 2 illustrates one example of gNB 102, various changes may be made to FIG. 2. For example, the gNB 102 could include any number of each component shown in FIG. 2. Also, various components in FIG. 2 could be combined, further subdivided, or omitted and additional components could be added according to particular needs.

[0104] FIG. 3 illustrates an example UE 116 according to embodiments of the present disclosure. The embodiment of the UE 116 illustrated in FIG. 3 is for illustration only, and the UEs 111-115 of FIG. 1 could have the same or similar configuration. However, UEs come in a wide variety of configurations, and FIG. 3 does not limit the scope of this disclosure to any particular implementation of a UE.

[0105] As shown in FIG. 3, the UE 116 includes antenna(s) 305, a transceiver(s) 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.

[0106] The transceiver(s) 310 receives, from the antenna 305, an incoming RF signal transmitted by a gNB of the network 100. The transceiver(s) 310 down-converts the incoming RF signal to generate an intermediate frequency (IF) or baseband signal. The IF or baseband signal is processed by RX processing circuitry in the transceiver(s) 310 and / or processor 340, which generates a processed baseband signal by filtering, decoding, and / or digitizing the baseband or IF signal. The RX processing circuitry sends the processed baseband signal to the speaker 330 (such as for voice data) or is processed by the processor 340 (such as for web browsing data).

[0107] TX processing circuitry in the transceiver(s) 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(s) 310 up-converts the baseband or IF signal to an RF signal that is transmitted via the antenna(s) 305.

[0108] The processor 340 can include one or more processors or other processing devices and execute the OS 361 stored in the memory 360 in order to control the overall operation of the UE 116. For example, the processor 340 could control the reception of DL channel signals and the transmission of UL channel signals by the transceiver(s) 310 in accordance with well-known principles. In some embodiments, the processor 340 includes at least one microprocessor or microcontroller.

[0109] The processor 340 can include circuitry and / or programming for facilitating clustering and power allocation for multi-TRP transmission. The processor 340 is also capable of executing other processes and programs resident in the memory 360. The processor 340 can move data into or out of the memory 360 as required by an executing process. 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 also coupled to the 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.

[0110] The processor 340 is also coupled to the input 350, which includes for example, a touchscreen, keypad, 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 may 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.

[0111] The memory 360 is coupled to the processor 340. Part of the memory 360 could include a random-access memory (RAM), and another part of the memory 360 could include a Flash memory or other read-only memory (ROM).

[0112] Although FIG. 3 illustrates one example of UE 116, various changes may be made to FIG. 3. For example, various components in FIG. 3 could be combined, further subdivided, or omitted and additional components could be added according to particular needs. As a particular example, the processor 340 could 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(s) 310 may include any number of transceivers and signal processing chains and may be connected to any number of antennas. Also, while FIG. 3 illustrates the UE 116 configured as a mobile telephone or smartphone, UEs could be configured to operate as other types of mobile or stationary devices.

[0113] FIG. 4 illustrates an example of horizontal TRP expansion 400 according to embodiments of the present disclosure. The embodiment of the horizontal TRP expansion 400 shown in FIG. 4 is for illustration only. Other embodiments of the horizontal TRP expansion 400 could be used without departing from the scope of this disclosure.

[0114] As illustrated in FIG. 4, the TRP 405 may increase the number of TXRUs horizontally in order to produce the horizontally expanded TRP 410 shown in FIGURE 4. Both the TRP 405 and the TRP 410 are denoted as two-dimensional (2D)-MMU because each TRP can be conceptually perceived as a uniform-rectangular-array.

[0115] FIG. 5 illustrates an example of back-to-back TRP configuration in a BCA 500 according to embodiments of the present disclosure. The embodiment of the back-to-back TRP configuration in a BCA 500 shown in FIG. 5 is for illustration only. Other embodiments of the back-to-back TRP configuration in a BCA 500 could be used without departing from the scope of this disclosure.

[0116] In some embodiments as illustrated in FIG. 5, TRP 505 and TRP 510 can be disposed in a back-to-back configuration in which antenna elements of the TRP 505 are positioned to radiate in an opposite direction from antenna elements of the TRP 510 in one BCA 515 and maintain a certain difference in facing angle. In some embodiments, the difference in facing angle is 180°.

[0117] FIG. 6 illustrates an example of 3D-MMU in a base station site 600 according to embodiments of the present disclosure. The embodiment of the example of 3D-MMU in a base station site 600 shown in FIG. 6 is for illustration only. Other embodiments of the example of 3D-MMU in a base station site 600 could be used without departing from the scope of this disclosure.

[0118] A cellular network is based on the concept of dividing the geographic area into smaller regions where a user equipment (UE) in each region is served by at least one associated TRP. The pair of back-to-back TRPs are deployed in one 3D-MMU package as shown in FIG. 5. Since two TRPs are facing the opposite direction, the inter-TRP mutual coupling within each 3D-MMU package is marginal.

[0119] As illustrated in FIG. 6, multiple 3D-MMU packages are used in one particular site. In this embodiment, to make 3D-MMU compatible with other cell associations, each site is divided into three 120° cells where each cell i includes two adjacent 60° sub-cells i(1)and i(2). Considering the sub-cell separation, the initial cell association relates the k-th UE to cell skwhen skis determined as: where is the reference signal received power (RSRP) received at UE k from sub-cell i(l)and Mkis the set of measurable cells of UE k. The prime TRP of UE k refers to the TRP from which UE k receives the highest RSRP.

[0120] FIG. 7 illustrates an example of 3D-MMU tier-1 clustering for a 2-ring hexagonal cell layout 700 according to embodiments of the present disclosure. The embodiment of the example of 3D-MMU tier-1 clustering for a 2-ring hexagonal cell layout 700 shown in FIG. 7 is for illustration only. Other embodiments of the example of 3D-MMU tier-1 clustering for a 2-ring hexagonal cell layout 700 could be used without departing from the scope of this disclosure.

[0121] In some embodiments, when a distributed unit (DU) is connected to multiple sites, separate sites can optionally cooperate to form a coordination TRP set. Since each coordination TRP set needs to be compatible with other cell associations in equation (1) while delivering diversified angle orientation, each tier-1 cluster can be defined as the union of three cells (equivalently, six sub-cells) as shown in FIG. 7. For example, cells 1, 6, and 20 (equivalently, sub-cells 1(1),1(2),6(1),6(2),20(1), and 20(2)) in FIG. 7 are configured to jointly support UEs initially attached to either cell 1, 6, or 20. This clustering can be expanded to the entire hexagonal grid as shown in FIG. 7. By performing coherent joint transmission (CJT) over six neighboring TRPs, the newly attached TRPs are converted from dominant interfering cells to serving cells, thereby significantly improving the signal quality in most cases. In some embodiments, each tier-1 cluster includes adjacent sub-cells from three different cell site sectors.

[0122] FIG. 8 illustrates an example of cluster-edges of tier-1 clusters 800 according to embodiments of the present disclosure. The embodiment of the example of cluster-edges of tier-1 clusters 800 shown in FIG. 8 is for illustration only. Other embodiments of the example of cluster-edges of tier-1 clusters 800 could be used without departing from the scope of this disclosure.

[0123] As illustrated in FIG. 8, in some embodiments, due to the fixed shape of tier-1 clusters, cluster-edge regions are inevitably introduced. UEs located in such fixed shape tier-1 clusters (e.g., triangle) may receive high interference from neighboring tier-1 cluster sub-cells. Cells expected to locate in the cluster-intersection typically have an even sub-cell number, i.e., i(2)as shown in FIG. 7 and FIG. 8.

[0124] FIG. 9 illustrates an example of a 1-ring hexagonal cell layout covered by both tier-1 clustering and tier-2 clustering 900 according to embodiments of the present disclosure. The embodiment of the example of a 1-ring hexagonal cell layout covered by both tier-1 clustering and tier-2 clustering 900 shown in FIG. 9 is for illustration only. Other embodiments of the example of a 1-ring hexagonal cell layout covered by both tier-1 clustering and tier-2 clustering 900 could be used without departing from the scope of this disclosure.

[0125] As illustrated in FIG. 9, in some embodiments, a tier-1 cluster is defined with six neighboring TRPs whereas a tier-2 cluster is defined with three neighboring TRPs which form a triangular shape.

[0126] FIGS. 10A and 10B illustrate an example of a UE being offloaded from a tier-1 cluster 1010 to a tier-2 cluster 1020 according to embodiments of the present disclosure. The embodiment of the example of a UE being offloaded from a tier-1 cluster 1010 to a tier-2 cluster 1020 shown in FIGS. 10A and 10B is for illustration only. Other embodiments of the example of a UE being offloaded from a tier-1 cluster 1010 to a tier-2 cluster 1020 could be used without departing from the scope of this disclosure.

[0127] In some embodiments, although the tier-1 clustering is beneficial to most UEs, a UE located close to the boundary of tier-1 clusters is likely to observe high inter-cluster interference since the prime TRP is far away from the UE. In this case, the second highest RSRP can be obtained from the neighboring tier-1 cluster and its value can be as high as the RSRP from the prime TRP as shown in FIG. 10A. Accordingly, a triangular tier-2 cluster as shown in FIG. 10B can be defined to offload the UE and mitigate severe inter-cluster interference in a user-centric manner.

[0128] In some embodiments, noting that is anchored between tier-1 and tier-2 clusters, a determination can be made whether to offload to tier-2 cluster by comparing the sum RSRP of the associated tier-2 cluster where the anchor sub-cell acts as the pivot between two tiers.

[0129] FIG. 11 illustrates an example of a geometric distribution of UEs 1100 according to embodiments of the present disclosure. The embodiment of the example of a geometric distribution of UEs 1100 shown in FIG. 11 is for illustration only. Other embodiments of the example of a geometric distribution of UEs 1100 could be used without departing from the scope of this disclosure.

[0130] As illustrated, FIG. 11 shows the distribution of UEs that are transferred to tier-2 clusters since the sum RSRP of the associated tier-2 cluster is higher than the one of the associated tier-1 cluster. It can be shown that most of such UEs are located in the highlighted triangles which are the collection of tier-2 clusters.

[0131] FIG. 12 illustrates an example of dynamic tier-1 cluster selection 1200 according to embodiments of the present disclosure. The embodiment of the example of dynamic tier-1 cluster selection 1200 shown in FIG. 12 is for illustration only. Other embodiments of the example of dynamic tier-1 cluster selection 1200 could be used without departing from the scope of this disclosure.

[0132] 3D-MMU Dynamic Cluster Selection for Multi-TRP CJT

[0133] As illustrated in FIG. 12, in some embodiments, dynamic tier-1 cluster selection may be provided. Dynamic tier-1 cluster selection is a mechanism in which the initially associated cell has freedom to be attached to either a 1st tier-1 cluster or a 2nd tier-1 cluster, where both of the 1st tier-1 cluster and the 2nd tier-1 cluster are configured to contain six neighboring TRPs. In one embodiment, the 2nd tier-1 cluster is a superset of a tier-2 cluster. This can eventually remove the cluster-edge issue described herein.

[0134] FIG. 13 illustrates an example of a geometric distribution for UEs connected to a particular cell 1300 according to embodiments of the present disclosure. The embodiment of the example of a geometric distribution for UEs connected to a particular cell 1300 shown in FIG. 13 is for illustration only. Other embodiments of the example of a geometric distribution for UEs connected to a particular cell 1300 could be used without departing from the scope of this disclosure.

[0135] As illustrated, FIG. 13 shows the distribution of UEs that are initially attached to a particular cell, for example cell 3. Some UEs have higher sum RSRP from the 1sttier-1 cluster of cell 3 whereas other UEs have higher sum RSRP from the 2ndtier-1 cluster of cell 3. Since it tends to divide the two groups with respect to the border between sub-cell 3(1)and 3(2), dynamic cluster selection provides a fair opportunity to both clusters, thereby improving a UEs’ signal quality due to the enhanced flexibility.

[0136] Power Allocation

[0137] Let the stacked channel between the k-th UE and a specific 3D-MMU cluster with N∈{3,6} TRPs with each having M TXRUs be

[0138] Subsequently, the channel matrix from N TRPs to K associated UEs can be combined as:

[0139] Note that H can be acquired through sounding reference signal for time division duplex or precoding matrix indicator for frequency division duplex. Assuming the use of a multi-user precoder, for example, a zero-forcing precoder of , an unnormalized precoders can be constructed from N TRPs toward the k-th UE as: where is the k-column of .

[0140] In some embodiments, the unnormalized primitive precoders need to be normalized. A normalization factor can be variously defined where appears in the normalized precoder as:

[0141] Then, the normalized stacked precoder from N TRPs toward the k-th UE is defined as:

[0142] needs to be carefully designed such that the transmit power from each TRP is uniformly or ununiformly shared across K UEs. On top of that, the normalized precoder needs to satisfy one or multiple conditions of the following: 1) precoder structure is preserved for interference nulling, i.e., for an arbitrary scalar η; 2) total TRP power constraint of is preserved; 3) per-TRP power constraint of is met for all n; and 4) per-TRP per-UE power constraint of is satisfied for all n and k. A system operator may choose one particular scheme based on their system requirement.

[0143] In some embodiments, equal power allocation is defined as . This scheme guarantees uniform per-TRP per-UE power of and total TRP power of for all TRPs, thereby utilizing the full resource of each TRP. However, since normalization factors are heterogeneously defined across TRPs, precoder structure is altered and interference may exist.

[0144] In some embodiments, flexible power allocation is defined as . Since the normalization factor is defined regardless of n for a certain UE k, this scheme guarantees that precoder structure is preserved. Also, total TRP power of is always met since normalization is obtained through the 2-norm of the stacked channel. However, the per-TRP per-UE power is unbalanced and biased toward the prime TRP of each UE. This means that the per-TRP per-UE power constraint is violated unless the exception case of for all n and m where n≠m, is met, which is not feasible. Note that, in the exception case, the flexible power allocation is equivalent to the equal power allocation. Because of the per-TRP per-UE power violation, it can be inferred that the per-TRP power constraint is not guaranteed where the extreme case happens when all UEs select the same TRP as their prime TRP.

[0145] In some embodiments, prime power allocation is defined as . Since is actually defined without reference to n, N TRPs associated with one particular UE k use the same scaling factor, thereby the precoder structure is unaltered. Note that the prime TRP of each UE k reports the transmit power of whereas the rest of the TRPs consume less power to operate in a more power-efficient manner. Therefore, this scheme satisfies total TRP transmit power, per-TRP transmit power, and per-TRP per-UE transmit power constraints. When all UEs designate the same TRP as their prime TRP as an extreme case, the highest total TRP power becomes which is still acceptable.

[0146] In some embodiments, two-stage prime power allocation is defined. An intermediate precoder is derived by following the prime power allocation as: where . Noting that UEs are randomly distributed across the field and choose their prime TRP based on the reported RSRP, it is straightforward that one particular TRP is elected as the prime TRP by a small subset of UEs. This means that, under the original prime power allocation, each TRP does not fully utilize its power resource. To further reinforce power utilization, the second-stage of the two-stage prime power allocation is defined as: where . Note that is less than or equal to 1 where the equality holds when all UEs identify the same TRP as their prime TRP. This additional process can guarantee that the TRP with the highest transmit power consumes a total TRP transmit power of 1. Since both steps are defined regardless of n, it is possible to maintain the precoder structure. Note that the total TRP power and per-TRP power constraints are preserved whereas the per-TRP per-UE power constraint is violated at a few TRPs, which results in non-uniform power allocation across UEs.

[0147] FIG. 14 illustrates an example method 1400 for clustering and power allocation for multi-TRP transmission according to embodiments of the present disclosure. The embodiment of an example method 1400 for clustering and power allocation for multi-TRP transmission shown in FIG. 14 is for illustration only. Other embodiments of an example method 1400 for clustering and power allocation for multi-TRP transmission could be used without departing from the scope of this disclosure.

[0148] As illustrated in FIG. 14, the method 1400 begins at step 1402, and includes providing multi-tier clustering to enable joint transmission across multiple transmit-receive-point (TRP) sets. At step 1404, the method includes utilizing one or more 2nd-tier clusters located in an intersection of one or more adjacent 1st-tier clusters to mitigate interference at cluster edges. At step 1406, the method includes providing dynamic cluster selectionto enable the joint transmission across the multiple TRPs while mitigating interference at cluster edges based on selecting a tailored cluster with respect to a signal power of each user equipment (UE)within the 1st-tier clusters.

[0149] FIG. 15 is a block diagram of a terminal or user equipment (UE) 1500 according to an embodiment of the disclosure. FIG. 15 corresponds to the example of the UE of FIG. 3.

[0150] The terminal is an electronic device capable of wireless communication, may include a User Equipment (UE), a portable phone, a smartphone, a tablet, an Internet of things (IoT) device, etc., having various form factors, and may perform wireless communication with a base station (BS) through a wireless channel.

[0151] Referring to FIG. 15, the UE 1500 may include at least one transceiver (hereinafter, referred to as simply "transceiver") 1501, at least one processor (hereinafter, referred to as simply "processor") 1502, and at least one memory (hereinafter, referred to as simply "memory") 1503. According to at least one or a combination of methods corresponding to the embodiments described in the present disclosure, the transceiver 1501, the processor 1502, and the memory 1503 of the UE 1500 may operate. However, components of the UE 1500 are not limited to the exemplary components illustrated in FIG. 15. In another embodiment, the UE 1500 may further include additional components in addition to the above-mentioned components, or some components may be omitted. Further, in some embodiments, any combination of the transceiver 1501, the processor 1502, or the memory 1503 may be integrated in the form of one component.

[0152] The transceiver 1501 may be a communication circuit or communication circuitry that enables the UE 1500 to perform wireless communication with a node or an entity of a network. For example, the transceiver 1501 may enable the UE 1500 to transmit or receive a signal to or from a BS through cellular communication, or to transmit or receive a signal to or from another UE through cellular communication. For example, the transceiver 1501 may support at least one of various cellular communication technologies including 3rd generation (3G), 4thgeneration (4G), long term evolution (LTE), 5th generation (5G) NR, 6thgeneration (6G), and various cellular wireless communication technologies supported by the transceiver (1501) may include all subsequent generations of evolved wireless communications.

[0153] According to an embodiment, the UE 1500 may include a plurality of transceivers. For example, in the case of supporting evolved-universal terrestrial radio access-new radio (E-UTRA-NR) sual connectivity (EN-DC), the UE 1500 may include a first transceiver supporting the 4G LTE wireless communication and a second transceiver supporting the 5G NR wireless communication. According to another embodiment, in the case of supporting NR-dual connectivity (NR-DC), the UE 1500 may include a plurality of transceivers supporting the 5G NR wireless communication. According to still another embodiment, in the case of supporting near field wireless communication, the UE 1500 may separately include a transceiver supporting at least one standard in the group of wireless communication protocol standards as defined in the protocol standards for Bluetooth®, wireless local area network (WLAN) network (including institute of electrical and electronics engineers (IEEE) 802.11-2016 standard or its amendments, e.g., 802.11ah, 802.11ad, 802.11ay, 802.11ax, 802.11az, 802.11ba, and 802.11be, without being limited thereto).

[0154] According to an embodiment, the transceiver 1501 may include various circuit structures used to transmit or receive signals to or from a BS through a wireless channel. The signals may include control information and data. For example, the transceiver 1501 may include a radio frequency (RF) transmitter for up-converting and amplifying the frequency of a transmitted signal and an RF receiver for low-noise-amplifying a received signal and down-converting the frequency thereof. The transceiver 1501 may output a signal received through a wireless channel to the processor 1502 and may transmit, through a wireless channel, a signal output from the processor 1502.

[0155] The processor 1502 may control general operations of the UE 1500 according to embodiments of the disclosure. The processor 1502 may be implemented by one or more integrated circuit (or circuitry) (IC) chips and may execute various data processings. The processor 1502 may include at least one electric circuit, and may execute instructions (or a program, codes, data, etc.) stored in the memory 1503, individually, collectively or in any combination thereof. Further, the processor 1502 may include a single-core processor or multi-core processor, and may include a processor assembly including a plurality of processing circuits (circuitry) according to a specific implementation scheme.

[0156] The processor 1502 may be electrically, operatively, or communicatively coupled to the transceiver 1501 to control the transceiver 1501.

[0157] The processor 1502 may include at least one processor (or processing circuitry), and the at least one processor may perform the following operations individually, collectively or in any combination thereof. For example, the processor 1502 may include a communication processor (CP) configured to control communication operations and an application processor (AP) configured to control execution of an upper layer (for example, an application layer) . In a specific embodiment, at least a part of the processor 1502 may be included in one chip and the other part of the processor 1502 may be included in another chip. Otherwise, at least one processor may be included in another component, for example, the transceiver 1501 or the memory 1503.

[0158] The processor 1502 may perform or control or cause an operation of the UE 1500 for executing at least one or a combination of methods according to embodiments of the disclosure. For example, the processor 1502 may control operations of the UE 1500 for processing a downlink signal received from a BS or generating and transmitting an uplink signal to a BS. To this end, the processor 1502 may execute a computer program, codes, or instructions stored in the memory 1503, so as to control other components of the UE 1500 to enable execution of various operations.

[0159] The memory 1503 corresponds to a hardware storage device capable of temporarily or permanently storing information and may include one or more storage media. For example, the memory 1503 may include a memory assembly including one or more storage media. For example, the one or more storage media may include permanent memory, such as a hard drive, flash memory, or read-only memory (ROM), semipermanent memory, such as random access memory (RAM), cache memory, or a combination thereof.

[0160] The memory 1503 may be electrically, operatively, or communicatively coupled to the processor 1502 and may be accessed by the processor 1502.

[0161] The memory 1503 may store a computer program, codes, or instructions executable by the processor 1502. According to an embodiment, a computer program, codes, or instructions executable by the processor 1502 may be either stored in a single memory device or separated and distributedly stored in two or more memory devices. By executing the instructions stored in the memory 1503, the processor 1502 may perform various functions according to an embodiment of the disclosure.

[0162] According to an embodiment of the disclosure, operations of the UE 1500 may be caused to be performed based on execution of instructions (or a computer program or codes) stored in the memory 1503 by at least one processor (or processing circuitry) configured to execute the same individually, collectively, or in any combination thereof, based on processing circuitry that is not configured to execute instructions, and / or based on components of processing circuitry that is not configured to execute instructions.

[0163] FIG. 16 is a block diagram of a base station (BS) 1600 according to an embodiment of the disclosure. FIG. 16 corresponds to the example of the gNB of FIG. 2.

[0164] The BS 1600 may perform wireless communication with at least one user equipment (UE) located within the area of the BS 1600 through a wireless channel.

[0165] Referring to FIG. 16, the BS 1600 may include at least one transceiver (hereinafter, referred to as simply "transceiver") 1601, at least one processor (hereinafter, referred to as simply "processor") 1602, and at least one memory (hereinafter, referred to as simply "memory") 1603. According to at least one or a combination of methods corresponding to the embodiments described in the present disclosure, the transceiver 1601, the processor 1602, and the memory 1603 of the BS 1600 may operate. However, components of the BS 1600 are not limited to the exemplary components illustrated in FIG. 16. In another embodiment, the BS 1600 may further include additional components in addition to the above-mentioned components, or some components may be omitted. Further, in some embodiments, any combination of the transceiver 1601, the processor 1602, or the memory 1603 may be integrated in the form of one component.

[0166] The transceiver 1601 may be a communication circuit or communication circuitry that enables the BS 1600 to perform wireless communication with a node or an entity of a network. For example, the transceiver 1601 may enable the BS 1600 to transmit or receive a signal to or from the UE X00 through cellular communication, or to transmit or receive a signal to or from another network entity through wireless communication. For example, the transceiver 1601 may support various cellular communication technologies including 3rd generation (3G), 4th generation (4G), long term evolution (LTE), 5th generation (5G) NR, 6th generation (6G), and various cellular wireless communication technologies supported by the transceiver (1601) may include all subsequent generations of evolved wireless communications.. According to an embodiment, the transceiver 1601 may include various circuit structures used to transmit or receive signals to or from a UE through a wireless channel. The signals may include control information and data. For example, the transceiver 1601 may include a radio frequency (RF) transmitter for up-converting and amplifying the frequency of a transmitted signal and an RF receiver for low-noise-amplifying a received signal and down-converting the frequency thereof. The transceiver 1601 may output a signal received through a wireless channel to the processor 1602 and may transmit, through a wireless channel, a signal output from the processor 1602.

[0167] Meanwhile, according to an embodiment of the present disclosure, the BS 1600 may perform communication with a node or an entity of a network through wired or wireless communication. For example, the BS 1600 may perform wired or wireless communication with an adjacent BS, or a node or an entity of a core network through a backhaul network. Although not illustrated in FIG. 16, when the BS 1600 performs wired communication, the BS 1600 may further include a separate network interface for wired communication in addition to the transceiver 1601. The network interface may be referred to as network interface circuitry or communication interface circuitry.

[0168] The processor 1602 may control general operations of the BS 1600 according to embodiments of the disclosure. The processor 1602 may be implemented by one or more integrated circuit (or circuitry) (IC) chips and may execute various data processings. The processor 1602 may include at least one electric circuit, and may execute instructions (or a program, codes, data, etc.) stored in the memory 1603, individually, collectively or in any combination thereof. Further, the processor 1602 may include a single-core processor or multi-core processor, and may include a processor assembly including a plurality of processing circuits (circuitry) according to a specific implementation scheme.

[0169] The processor 1602 may be electrically, operatively, or communicatively coupled to the transceiver 1601 to control the transceiver 1601.

[0170] The processor 1602 may include at least one processor (or processing circuitry), and the at least one processor may perform the following operations individually, collectively or in any combination thereof. In a specific embodiment, at least a part of the processor 1602 may be included in one chip and the other part of the processor 1602 may be included in another chip. Otherwise, at least one processor may be included in another component, for example, the transceiver 1601 or the memory 1603.

[0171] The processor 1602 may perform or control or cause an operation of the BS 1600 for executing at least one or a combination of methods according to embodiments of the disclosure. For example, the processor 1602 may control operations of the BS 1600 for generating and transmitting a downlink signal to a UE or processing an uplink signal received from a UE. Otherwise, the BS 1600 may transmit or receive a signal to or from a neighboring BS, transfer a signal received from a UE to an upper node of the network, or transmit a signal transferred from an upper node of the network to a UE. To this end, the processor 1602 may execute a computer program, codes, or instructions stored in the memory 1603, so as to control other components of the BS 1600 to enable execution of various operations.

[0172] The memory 1603 corresponds to a hardware storage device capable of temporarily or permanently storing information and may include one or more storage media. For example, the memory 1603 may include a memory assembly including one or more storage media. For example, the one or more storage media may include permanent memory, such as a hard drive, flash memory, or read-only memory (ROM), semipermanent memory, such as random access memory (RAM), cache memory, or a combination thereof.

[0173] The memory 1603 may be electrically, operatively, or communicatively coupled to the processor 1602 and may be accessed by the processor 1602.

[0174] The memory 1603 may store a computer program, codes, or instructions executable by the processor 1602. According to an embodiment, a computer program, codes, or instructions executable by the processor 1602 may be either stored in a single memory device or separated and distributedly stored in two or more memory devices. By executing the instructions stored in the memory 1603, the processor 1602 may perform various functions according to an embodiment of the disclosure.

[0175] According to an embodiment of the disclosure, operations of the BS 1600 may be caused to be performed based on execution of instructions (or a computer program or codes) stored in the memory 1603 by at least one processor (or processing circuitry) configured to execute the same individually, collectively, or in any combination thereof, based on processing circuitry that is not configured to execute instructions, and / or based on components of processing circuitry that is not configured to execute instructions.

[0176] The UE or the base station may perform various communication procedures related to the control plane or the user plane by cooperating with one or more network entities based on wireless communication. For example, the UE may communicate with network entity such as an Access and Mobility Management Function (AMF) or a Session Management Function (SMF) via the base station, or the base station may perform at least one communication procedure by directly transmitting and receiving signals to / from, or relaying signals between, the network entities.

[0177] The structure of the above-described network entity will be described in more detail with reference to the drawings.

[0178] FIG. 17 is a block diagram of a network entity 1700 according to an embodiment of the disclosure.

[0179] The network entity 1700 may include an entity (apparatus, device, or server, etc.) that performs one or more network functions (NFs) or a part of a network function constituting a core network (e.g., a 5th generation (5G) core (5GC)) in a communication system. In this case, multiple NFs may be implemented within a single network entity, or a single NF may be distributed and implemented across a plurality of network entities. In addition, when an NF is implemented within the network entity, the NF may be implemented in the form of software, and in such a case, a program for operating the NF may be stored in memory of the network entity 1700.

[0180] A single NF may be implemented by one or more instances, which may be deployed on the same network entity or distributed across multiple network entities to operate. The instance may be a software unit that logically executes a specific network function, and may be implemented in a form that is decoupled from physical hardware resources. Further, one or more NFs may be implemented in the form of one network slice to operate to satisfy specifications required by a particular service.

[0181] The NF may include at least one of an access and mobility management function (AMF), a session management function (SMF), a local session management function (L-SMF), a user plane function (UPF), a local user plane function (L-UPF), a policy control function (PCF), a unified data management (UDM), a unified data repository (UDR), a network exposure function (NEF), a network repository function (NRF), an application function (AF), a network slice selection function (NSSF), a network data analytics function (NWDAF), a network slice admission control function (NSACF), an authentication server function (AUSF), or a data network (DN).

[0182] Referring to FIG. 17, the network entity 1700 may include at least one network interface 1701, at least one processor 1702 (hereinafter, "processor"), and at least one memory 1703 (hereinafter, "memory"). As described above, a NF may be implemented in the form of a physical device such as the network entity 1700, or may be virtualized and executed in the form of an instance. When implemented as an instance, the NF need not necessarily include physical components as illustrated in FIG. 17. In such a case, the instance may be logically represented as comprising one or more logical functional elements.

[0183] According to at least one or a combination of methods corresponding to the embodiments described in the present disclosure, the network interface 1701, the processor 1702, and the memory 1703 of the network entity 1700 may operate. However, components of the network entity 1700 are not limited to the exemplary components illustrated in FIG. 17. In another embodiment, the network entity 1700 may further include additional components in addition to the above-mentioned components, or some components may be omitted. Further, in an embodiment, the network interface 1701, the processor 1702, or the memory 1703 may be integrated in the form of one component.

[0184] The network interface 1701 is a collective term for a transmitter part of the network entity 1700 and a receiver part of the network entity 1700, and may be a communication circuit for transmitting or receiving a signal to or from a user equipment (UE), a base station (BS), or another network entity. Here, the communication circuit may include both a communication circuit for wireless communication and a communication circuit for a wired communication. For example, the network interface 1701 may include a circuit, logic, hardware, etc., configured to exchange a control plane message or a user plane message with a UE, a BS, or other core network entities through wireless communication or wired communication. The network interface 1701 may operate using various protocols (e.g., non-access stratum (NAS) protocol). The network interface 1701 may also be referred to, for convenience of description or depending on implementation, as communication circuitry, network interface circuitry, or a communication interface circuitry.

[0185] The processor 1702 may control general operations of the network entity 1700 according to embodiments of the disclosure. The processor 1702 may be implemented by one or more integrated circuit (or circuitry) (IC) chips and may execute various data processings. The processor 1702 may include at least one electric circuit, and may execute instructions (or a program, codes, data, etc.) stored in the memory 1703, individually, collectively or in any combination thereof. Further, the processor 1702 may include a single-core processor or multi-core processor, and may include a processor assembly including a plurality of processing circuits (circuitry) according to a specific implementation scheme. Further, it should be noted that, according to another embodiment, in a case where NF is implemented in the form of an instance, the network function may be not necessarily configured by physical hardware.

[0186] According to an embodiment, the processor 1702 may be electrically, operatively, or communicatively coupled to the network interface 1701 to control the network interface 1701.

[0187] The processor 1702 may include at least one processor (or processing circuitry), and the at least one processor may perform the following operations individually, collectively or in any combination thereof. In a specific embodiment, at least a part of the processor 1702 may be included in one chip and the other part of the processor 1702 may be included in another chip. Otherwise, at least one processor may be included in another component, for example, the network interface 1701 or the memory 1703.

[0188] The processor 1702 may perform or control or cause an operation of the network entity 1700 for executing at least one or a combination of methods according to embodiments of the disclosure. For example, the processor 1702 may control operations of the network entity 1700 for exchanging a control plane message or a user plane message with a UE, a BS, or other core network entities through wireless or wired communication, using various protocols (e.g., NAS protocol). To this end, the processor 1702 may execute a computer program, codes, or instructions stored in the memory 1703, so as to control other components of the network entity 1700 to enable execution of various operations.

[0189] The memory 1703 corresponds to a hardware storage device capable of temporarily or permanently storing information and may include one or more storage media. For example, the memory 1703 may include a memory assembly including one or more storage media. For example, the one or more storage media may include permanent memory, such as a hard drive, flash memory, or read-only memory (ROM), semipermanent memory, such as random access memory (RAM), cache memory, or a combination thereof.

[0190] The memory 1703 may be electrically, operatively, or communicatively coupled to the processor 1702 and may be accessed by the processor 1702.

[0191] The memory 1703 may store a computer program, codes, or instructions executable by the processor 1702. According to an embodiment, a computer program, codes, or instructions executable by the processor 1702 may be either stored in a single memory device or separated and distributedly stored in two or more memory devices. By executing the instructions stored in the memory 1703, the processor 1702 may perform various functions according to an embodiment of the disclosure.

[0192] According to an embodiment of the disclosure, operations of the network entity 1700 may be caused to be performed based on execution of instructions (or a computer program or codes) stored in the memory 1703 by at least one processor (or processing circuitry) configured to execute the same individually, collectively, or in any combination thereof, based on processing circuitry that is not configured to execute instructions, and / or based on components of processing circuitry that is not configured to execute instructions.

[0193] In one embodiment, a method for clustering and power allocation for multi-TRP transmission providing multi-tier clustering to enable joint transmission across multiple transmit-receive-point (TRP) sets. The method includes utilizing one or more 2nd-tier clusters located in an intersection of one or more adjacent 1st-tier clusters to mitigate interference at cluster edges, and providing dynamic cluster selectionto enable the joint transmission across the multiple TRPs while mitigating interference at cluster edges based on selecting a tailored cluster with respect to a signal power of each user equipment (UE)within the 1st-tier clusters.

[0194] In another embodiment, a system comprises one or more 2nd-tier clusters located in an intersection of one or more adjacent 1st-tier clusters to mitigate interference at cluster edges. The system is configured to: provide multi-tier clustering to enable joint transmission across multiple transmit-receive-point (TRP) sets; and provide dynamic cluster selectionto enable the joint transmission across the multiple TRP sets while mitigating interference at cluster edges based on selecting a tailored cluster with respect to a signal power of each user equipment (UE)within the 1st-tier clusters.

[0195] In one embodiment, each TRP set comprises a first TRP and a second TRP in a back-to-back configuration in which antenna elements of the first TRP are positioned to radiate in an opposite direction from antenna elements of the second TRP.

[0196] In one embodiment, each 1st-tier cluster is defined as a union of three cell site sectors from three different cell sites to provide 1st-tier clustering; each cell site sector comprises two sub-cells; and each 1st-tier cluster does not overlap with another 1st-tier cluster.

[0197] In one embodiment, 2nd-tier clustering is defined to allow cooperation of cell site sectors not facilitated by the 1st-tier clustering; each 2nd-tier cluster comprises a single sub-cell from each of three cell site sectors; and each 2nd-tier cluster is within an intersection of three 1st-tier clusters.

[0198] In one embodiment, the method includes defining a first set of 1st-tier clusters and a second set of 1st-tier clusters; each of the first set of 1st-tier clusters and the second set of 1st-tier clusters has six neighboring TRPs; an initially associated cell site is configured to be attached to either one of the first set of 1sttier clusters or one of the second set of 1sttier clusters by choosing which other cell sites to append; and each of the second set of 1st-tier clusters is a superset of an associated 2nd-tier cluster.

[0199] In one embodiment, the method includes utilizing one or more power allocation schemes across multiple TRPs to satisfy one or more constraints.

[0200] In one embodiment, the one or more power allocation schemes comprises equal power allocation across TRPs or weighted equal power allocation across TRPs.

[0201] In one embodiment, the one or more power allocation schemes comprises flexible power allocation across TRPs.

[0202] In one embodiment, the one or more power allocation schemes comprises prime power allocation or local prime allocation across TRPs.

[0203] In one embodiment, the one or more power allocation schemes comprises two-stage prime power allocation across TRPs.

[0204] The above flowchart illustrates an example method or process that can be implemented in accordance with the principles of the present disclosure and various changes could be made to the methods or processes illustrated in the flowcharts.　For example, while shown as a series of steps, various steps could overlap, occur in parallel, occur in a different order, or occur multiple times. In another example, steps may be omitted or replaced by other steps.

[0205] Although the present disclosure has been described with an exemplary embodiment, various changes and modifications may be suggested to one skilled in the art. It is intended that the present disclosure encompass such changes and modifications as fall within the scope of the appended claims. None of the description in this application should be read as implying that any particular element, step, or function is an essential element that must be included in the claims scope. The scope of patented subject matter is defined by the claims.

[0206] Meanwhile, although specific embodiments of the present disclosure have been described in detail, various modifications may be made without departing from the scope of the present disclosure. Therefore, the scope of the present disclosure should not be limited to the described embodiments, but should be defined by the claims and equivalents thereof.

Claims

1.A method comprising:providing multi-tier clustering to enable joint transmission across multiple transmit-receive-point (TRP) sets, including:utilizing one or more 2nd-tier clusters located in an intersection of one or more adjacent 1st-tier clusters to mitigate interference at cluster edges; andproviding dynamic cluster selectionto enable the joint transmission across the multiple TRP sets while mitigating interference at cluster edges based on selecting a tailored cluster with respect to a signal power of each user equipment (UE)within the 1st-tier clusters.2.The method of claim 1, wherein each TRP set comprises a first TRP and a second TRP in a back-to-back configuration in which antenna elements of the first TRP are positioned to radiate in an opposite direction from antenna elements of the second TRP.3.The method of claim 1, wherein:each 1st-tier cluster is defined as a union of three cell site sectors from three different cell sites to provide 1st-tier clustering;each cell site sector comprises two sub-cells; andeach 1st-tier cluster does not overlap with another 1st-tier cluster.4.The method of claim 3, wherein:2nd-tier clustering is defined to allow cooperation of cell site sectors not facilitated by the 1st-tier clustering;each 2nd-tier cluster comprises a single sub-cell from each of three cell site sectors; andeach 2nd-tier cluster is within an intersection of three 1st-tier clusters.5.The method of claim 1, wherein:providing dynamic cluster selection comprises defining a first set of 1st-tier clusters and a second set of 1st-tier clusters;each of the first set of 1st-tier clusters and the second set of 1st-tier clusters has six neighboring TRPs;an initially associated cell site is configured to be attached to either one of the first set of 1sttier clusters or one of the second set of 1sttier clusters by choosing which other cell sites to append; andeach of the second set of 1st-tier clusters is a superset of an associated 2nd-tier cluster.6.The method of claim 1, further comprising utilizing one or more power allocation schemes across multiple TRPs to satisfy one or more constraints.7.The method of claim 6, wherein the one or more power allocation schemes comprises equal power allocation across TRPs or weighted equal power allocation across TRPs.8.The method of claim 6, wherein the one or more power allocation schemes comprises flexible power allocation across TRPs.9.The method of claim 6, wherein the one or more power allocation schemes comprises prime power allocation or local prime allocation across TRPs.10.The method of claim 6, wherein the one or more power allocation schemes comprises two-stage prime power allocation across TRPs.11.A system comprising:one or more 2nd-tier clusters located in an intersection of one or more adjacent 1st-tier clusters to mitigate interference at cluster edges, the system configured to:provide multi-tier clustering to enable joint transmission across multiple transmit-receive-point (TRP) sets; andprovide dynamic cluster selectionto enable the joint transmission across the multiple TRP sets while mitigating interference at cluster edges based on selecting a tailored cluster with respect to a signal power of each user equipment (UE)within the 1st-tier clusters.12.The system of claim 11, wherein each TRP set comprises a first TRP and a second TRP in a back-to-back configuration in which antenna elements of the first TRP are positioned to radiate in an opposite direction from antenna elements of the second TRP.13.The system of claim 11, wherein:each 1st-tier cluster is defined as a union of three cell site sectors from three different cell sites to provide 1st-tier clustering;each cell site sector comprises two sub-cells; andeach 1st-tier cluster does not overlap with another 1st-tier cluster.14.The system of claim 13, wherein:2nd-tier clustering is defined to allow cooperation of cell site sectors not facilitated by the 1st-tier clustering;each 2nd-tier cluster comprises a single sub-cell from each of three cell site sectors; andeach 2nd-tier cluster is within an intersection of three 1st-tier clusters.15.The system of claim 11, wherein:the system is further configured to define a first set of 1st-tier clusters and a second set of 1st-tier clusters;each of the first set of 1st-tier clusters and the second set of 1st-tier clusters has six neighboring TRPs;an initially associated cell site is configured to be attached to either one of the first set of 1sttier clusters or one of the second set of 1sttier clusters by choosing which other cell sites to append; andeach of the second set of 1st-tier clusters is a superset of an associated 2nd-tier cluster.

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