Apparatus and method for performing multicarrier scheduling in wireless communication system

Abstract

An object of the present disclosure is to perform multicarrier scheduling in a wireless communication system, and a method of operating a user equipment (UE) may comprise the steps of: performing an access procedure with a base station; performing a connection establishment process on the base station and the primary cell; performing a connection establishment procedure on the base station and the at least one secondary cell; receiving downlink control information (DCI) from the base station; and receiving data using the resource indicated by the DCI.

Description

Technical Field

[0001] The following description relates to a wireless communication system, and to an apparatus and a method for performing multi-carrier scheduling in the wireless communication system. Background Art

[0002] Wireless communication systems have been widely deployed to provide various types of communication services, such as voice or data. Generally speaking, wireless communication systems are multiple access systems that support communication for multiple users by sharing available system resources (bandwidth, transmission power, etc.). Examples of multiple access systems include code division multiple access (CDMA) systems, frequency division multiple access (FDMA) systems, time division multiple access (TDMA) systems, orthogonal frequency division multiple access (OFDMA) systems, and single carrier frequency division multiple access (SC-FDMA) systems.

[0003] In particular, because a large number of communication devices require a large communication capacity, enhanced mobile broadband (eMBB) communication technology is being proposed compared to conventional radio access technology (RAT). In addition, not only large-scale machine type communication (massive MTC) that provides various services anytime and anywhere by connecting multiple devices and objects is being proposed, but also a communication system that takes into account services / user terminal equipment (UE) that are sensitive to reliability and latency is being proposed. Various technical configurations are proposed for this purpose. Summary of the invention

[0004] Technical issues

[0005] The present disclosure may provide an apparatus and method for more efficiently allocating resources in a wireless communication system.

[0006] The present disclosure may provide an apparatus and method for performing multi-carrier scheduling in a wireless communication system.

[0007] The present disclosure may provide an apparatus and method for allocating resources to a plurality of cells using a Physical Downlink Control Channel (PDCCH) of one cell in a wireless communication system supporting carrier aggregation.

[0008] The present disclosure may provide an apparatus and method for performing scheduling on a Physical Downlink Shared Channel (PDSCH) or a Physical Uplink Shared Channel (PUSCH) of multiple cells using a PDCCH of one cell in a wireless communication system supporting carrier aggregation.

[0009] The present disclosure may provide an apparatus and method for transmitting and receiving DCI (Downlink Control Information) including scheduling information for a plurality of cells through a PDCCH of one cell in a wireless communication system.

[0010] The present disclosure may provide an apparatus and method for configuring an FDRA (Frequency Domain Resource Allocation) field including scheduling information for a plurality of cells in a wireless communication system supporting carrier aggregation.

[0011] The present disclosure may provide an apparatus and method for allocating frequency domain resources to a plurality of cells based on an RB (Resource Block) of a reference cell among the plurality of cells for carrier aggregation in a wireless communication system.

[0012] The present disclosure may provide an apparatus and method for allocating frequency domain resources to a plurality of cells based on a difference between an RB of a reference cell and RBs of other cells among the plurality of cells for carrier aggregation in a wireless communication system.

[0013] The present disclosure may provide an apparatus and method for allocating frequency domain resources of a plurality of cells based on BWP (Bandwidth Part) of the plurality of cells for carrier aggregation in a wireless communication system.

[0014] The present disclosure may provide an apparatus and method for dividing a plurality of cells for carrier aggregation into a plurality of cell groups in a wireless communication system and indicating frequency domain resources through a PDCCH for one cell of each cell group.

[0015] The technical objectives to be achieved by the present disclosure are not limited to the contents mentioned above, and those skilled in the art to which the technical configuration of the present disclosure is applied can consider other technical objectives not mentioned therein from the embodiments of the present disclosure to be described below.

[0016] Technical Solution

[0017] As an example of the present disclosure, a method of operating a user equipment (UE) in a wireless communication system may include: performing an access procedure with a base station, performing a connection establishment procedure with the base station for a primary cell, performing a connection establishment procedure with the base station for at least one secondary cell, receiving downlink control information (DCI) from the base station, and receiving data using resources indicated by the DCI. The DCI may include information indicating resources allocated in a plurality of cells including a primary cell and at least one secondary cell and information indicating at least one cell that is not actually scheduled among the primary cell and the at least one secondary cell.

[0018] As an example of the present disclosure, a method of operating a base station in a wireless communication system may include: performing an access procedure with a user equipment (UE), performing a connection establishment procedure for a primary cell of the UE, performing a connection establishment procedure for at least one secondary cell of the UE, sending downlink control information (DCI) to the UE, and sending data using resources indicated by the DCI. The DCI may include information indicating resources allocated in a plurality of cells including a primary cell and at least one secondary cell and information indicating at least one cell that is not actually scheduled among the primary cell and the at least one secondary cell.

[0019] As an example of the present disclosure, a user equipment (UE) in a wireless communication system may include a transceiver and a processor connected to the transceiver. The processor may perform an access procedure with a base station, perform a connection establishment procedure with a base station for a primary cell, perform a connection establishment procedure with a base station for at least one secondary cell, receive downlink control information (DCI) from the base station, and receive data using resources indicated by the DCI. The DCI may include information indicating resources allocated in a plurality of cells including a primary cell and at least one secondary cell, and information indicating at least one cell that is not actually scheduled among the primary cell and at least one secondary cell.

[0020] As an example of the present disclosure, a base station in a wireless communication system may include a transceiver and a processor connected to the transceiver. The processor may perform an access procedure with a user equipment (UE), perform a connection establishment procedure for a primary cell of the UE, perform a connection establishment procedure for at least one secondary cell of the UE, send downlink control information (DCI) to the UE, and send data using resources indicated by the DCI. The DCI may include information indicating resources allocated in a plurality of cells including a primary cell and at least one secondary cell, and information indicating at least one cell that is not actually scheduled among the primary cell and at least one secondary cell.

[0021] As an example of the present disclosure, a communication device may include: at least one processor; and at least one computer memory, which is connected to the at least one processor to store instructions that guide operations when executed by the at least one processor. The operations may include: performing an access process with a base station, performing a connection establishment process with a base station for a primary cell, performing a connection establishment process with a base station for at least one secondary cell, receiving downlink control information (DCI) from the base station, and receiving data using resources indicated by the DCI. The DCI may include information indicating resources allocated in a plurality of cells including a primary cell and at least one secondary cell, and information indicating at least one cell that is not actually scheduled among the primary cell and at least one secondary cell.

[0022] As an example of the present disclosure, a non-transitory computer-readable medium storing at least one instruction may include at least one instruction executable by a processor. The at least one instruction may instruct a device to perform an access procedure with a base station, perform a connection establishment procedure with a base station for a primary cell, perform a connection establishment procedure with a base station for at least one secondary cell, receive downlink control information (DCI) from the base station, and receive data using resources indicated by the DCI. The DCI may include information indicating resources allocated in a plurality of cells including a primary cell and at least one secondary cell, and information indicating at least one cell that is not actually scheduled among the primary cell and at least one secondary cell.

[0023] The above-mentioned aspects of the present disclosure are only a part of exemplary embodiments of the present disclosure, and those skilled in the art can derive and understand various embodiments reflecting the technical features of the present disclosure based on the following detailed description of the present disclosure.

[0024] Beneficial Effects

[0025] As is apparent from the above description, the embodiments of the present disclosure have the following effects.

[0026] According to the present disclosure, scheduling of multiple cells can be efficiently performed.

[0027] Those skilled in the art will appreciate that the effects that can be achieved by the embodiments of the present disclosure are not limited to the above effects, and other beneficial effects of the present disclosure will be more clearly understood from the following detailed description. That is, those skilled in the art can derive unexpected effects according to the embodiments of the present disclosure from the embodiments of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The accompanying drawings are provided to help understand the present disclosure, and embodiments of the present disclosure may be provided together with the detailed description. However, the technical features of the present disclosure are not limited to specific drawings, and the features disclosed in each drawing may be combined with each other to form new embodiments. The reference numerals in each drawing may refer to structural elements.

[0029] Figure 1 An example of a structure of a wireless communication system to which the present disclosure can be applied is illustrated.

[0030] Figure 2 An example of a wireless device suitable for use with the present disclosure is shown.

[0031] Figure 3 A frame structure in a wireless communication system to which the present disclosure can be applied is illustrated.

[0032] Figure 4 An example of a resource grid in a wireless communication system to which the present disclosure may be applied is illustrated.

[0033] Figure 5 An example of a physical resource block in a wireless communication system to which the present disclosure can be applied is illustrated.

[0034] Figure 6 An example of a slot structure in a wireless communication system to which the present disclosure can be applied is illustrated.

[0035] Figure 7 An example of a physical channel used in a wireless communication system to which the present disclosure can be applied and an example of a general signal transmission and reception method using the physical channel are illustrated.

[0036] Figure 8 An example of an FDRA method based on the maximum number of RBs (G) in a wireless communication system according to an embodiment of the present disclosure is illustrated.

[0037] Fig. 9 An example of an FDRA method based on a minimum number of RBs (G) in a wireless communication system according to an embodiment of the present disclosure is illustrated.

[0038] Fig.10 An example of a shared-common FDRA bit information configuration method in a wireless communication system according to an embodiment of the present disclosure is illustrated.

[0039] Fig.11 An example of a cell group for multi-carrier Physical Downlink Control Channel (PDCCH) scheduling in a wireless communication system according to an embodiment of the present disclosure is illustrated.

[0040] Fig.12 An example of separate-delta FDRA information configuration in a wireless communication system according to an embodiment of the present disclosure is illustrated.

[0041] Fig.13 An example of a process in which a base station performs communication according to multi-carrier scheduling in a wireless communication system according to an embodiment of the present disclosure is illustrated.

[0042] Fig.14 An example of a process in which a terminal performs communication according to multi-carrier scheduling in a wireless communication system according to an embodiment of the present disclosure is illustrated.

[0043] Fig.15 An example of a process for indicating whether to perform scheduling on each cell using FDRA information in a wireless communication system according to an embodiment of the present disclosure is illustrated.

[0044] Fig.16 An example of a process for performing multi-carrier scheduling according to a shared-common method in a wireless communication system according to an embodiment of the present disclosure is illustrated.

[0045] Fig.17An example of a process for performing multi-carrier scheduling according to a separate-incremental method in a wireless communication system according to an embodiment of the present disclosure is illustrated.

[0046] Fig.18 An example of a process for performing multi-carrier scheduling according to a separate-equal method in a wireless communication system according to an embodiment of the present disclosure is illustrated. DETAILED DESCRIPTION

[0047] The embodiment of the present disclosure described below is a combination of elements and features of the present disclosure in a particular form. Unless otherwise mentioned, elements or features may be considered to be selective. Each element or feature may be put into practice without being combined with other elements or features. In addition, embodiments of the present disclosure may be constructed by combining some elements and / or features. The order of operations described in the embodiments of the present disclosure may be rearranged. Some structures or elements of any one embodiment may be included in another embodiment and may be replaced with the corresponding structures or features of another embodiment.

[0048] In the description of the drawings, processes or steps that render the scope of the present disclosure unnecessarily ambiguous will be omitted, and processes or steps that can be understood by those skilled in the art will be omitted.

[0049] Throughout the specification, when a part "includes" or "comprises" a component, this indicates that other components are not excluded and may further be included, unless otherwise specified. The terms "unit", "-or / er" and "module" described in this specification indicate a unit for processing at least one function or operation, which can be implemented by hardware, software or a combination thereof. In addition, "a" or "an", "one", "the", etc. in the context of the present disclosure (more specifically, in the context of the appended claims) may include singular expressions and plural expressions, unless otherwise specified in the specification or unless the context clearly indicates otherwise.

[0050] In the embodiments of the present disclosure, the data transmission and reception relationship between a base station (BS) and a mobile station is mainly described. The BS refers to a terminal node of a network, which directly communicates with the mobile station. A specific operation described as being performed by the BS may be performed by an upper node of the BS.

[0051] That is, it is apparent that in a network composed of a plurality of network nodes including a BS, various operations performed for communication with a mobile station may be performed by the BS or network nodes other than the BS. The term "BS" may be replaced with a fixed station, a Node B, an evolved Node B (eNode B or eNB), an advanced base station (ABS), an access point, etc.

[0052] In an embodiment of the present disclosure, the term terminal may be replaced with UE, mobile station (MS), subscriber station (SS), mobile subscriber station (MSS), mobile terminal, advanced mobile station (AMS), etc.

[0053] A transmitter is a fixed and / or mobile node that provides data services or voice services, and a receiver is a fixed and / or mobile node that receives data services or voice services. Thus, on the uplink (UL), the mobile station can act as a transmitter and the BS can act as a receiver. Similarly, on the downlink (DL), the mobile station can act as a receiver and the BS can act as a transmitter.

[0054] The embodiments of the present disclosure may be supported by at least one of the standard specifications disclosed for wireless access systems including the Institute of Electrical and Electronics Engineers (IEEE) 802.xx system, the 3rd Generation Partnership Project (3GPP) system, the 3GPP Long Term Evolution (LTE) system, the 3GPP Fifth Generation (5G) New Radio (NR) system, and the 3GPP2 system. Specifically, the embodiments of the present disclosure may be supported by the standard specifications 3GPP TS 36.211, 3GPP TS 36.212, 3GPP TS 36.213, 3GPP TS 36.321, and 3GPP TS 36.331.

[0055] In addition, the embodiments of the present disclosure are applicable to other radio access systems and are not limited to the above-mentioned systems. For example, the embodiments of the present invention are applicable to systems applied after the 3GPP 5G NR system and are not limited to a specific system.

[0056] That is, steps or parts that are not described to clarify the technical features of the present disclosure may be supported by those documents. In addition, all terms as proposed herein may be interpreted by standard documents.

[0057] Embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings. The detailed description, which will be given below with reference to the accompanying drawings, is intended to explain exemplary embodiments of the present disclosure, rather than to show the only embodiments that can be implemented according to the present disclosure.

[0058] The following detailed description includes specific terms in order to provide a thorough understanding of the present disclosure. However, it is obvious to those skilled in the art that other terms may be used to replace specific terms without departing from the technical spirit and scope of the present disclosure.

[0059] Embodiments of the present disclosure can be applied to various radio access systems such as code division multiple access (CDMA), frequency division multiple access (FDMA), time division multiple access (TDMA), orthogonal frequency division multiple access (OFDMA), single carrier frequency division multiple access (SC-FDMA), etc.

[0060] Hereinafter, in order to clarify the following description, the description is based on the 3GPP communication system (e.g., LTE, NR, etc.), but the technical spirit of the present disclosure is not limited to this. LTE may refer to the technology after 3GPP TS 36.xxx version 8. Specifically, the LTE technology after 3GPP TS 36.xxx version 10 may be referred to as LTE-A, and the LTE technology after 3GPP TS 36.xxx version 13 may be referred to as pre-LTE-A. 3GPP NR may refer to the technology after TS 38.xxx version 15. 3GPP 6G may refer to the technology after TS version 17 and / or version 18. "xxx" may refer to the detailed number of the standard document. LTE / NR / 6G may be collectively referred to as the 3GPP system.

[0061] 3GPP 6G may refer to post-3GPP NR technology based on the 3GPP system. 3GPP 6G may not be limited to a version or a specific TS document, and its name may have a different form from 3GPP 6G. That is, 3GPP 6G may refer to a technology introduced after 3GPP NR, and is not limited to a specific form.

[0062] The following description will mainly focus on the 3GPP NR system, but is not limited thereto, and can be applied to 3GPP 6G. In addition, the content described below may be partially modified to be used in consideration of the 3GPP 6G system, and is not limited to a specific form. However, in the following, for ease of explanation, the 3GPP NR system will be mainly described. For the background technology, terms, abbreviations, etc. used in this disclosure, please refer to the matters described in the standard documents published before this disclosure. For example, standard documents 36.xxx and 38.xxx may be referenced.

[0063] Overall system

[0064] As more and more communication devices require greater communication capacity, the demand for mobile broadband communications that are more enhanced than existing radio access technologies (RATs) is rising. In addition, large-scale machine type communications (MTC) that provide various services anytime and anywhere by connecting multiple devices and things is also one of the main issues worth considering in the next generation of communications. In addition, the design of communication systems that consider services / terminals that are sensitive to reliability and latency is also under discussion. Therefore, the introduction of next-generation RATs that consider enhanced mobile broadband communications (eMBB), massive MTC (mMTC), ultra-reliable low-latency communications (URLLC), etc. is under discussion, and for convenience, the corresponding technology is referred to as NR in this disclosure. NR is an expression representing an example of 5G RAT.

[0065] The new RAT system including NR uses an OFDM transmission method or a similar transmission method. The new RAT system may follow OFDM parameters different from those of LTE. Alternatively, the new RAT system may follow the parameter set of the existing LTE / LTE-A as is, but support a wider system bandwidth (e.g., 100MHz). Alternatively, one cell may support multiple parameter sets. In other words, terminals operating according to different parameter sets may coexist in one cell.

[0066] A parameter set corresponds to one subcarrier spacing in the frequency domain. Because the reference subcarrier spacing is scaled by an integer N, different parameter sets can be defined.

[0067] In addition, the new RAT system including 6G may be considered as the next generation RAT. The new RAT system including 6G may consider i) very high data speed per device, ii) a large number of connected devices, iii) global connectivity, iv) very low latency, v) reduced energy consumption of battery-free IoT devices, vi) ultra-high reliability connectivity, and vii) connectivity intelligence with machine learning capabilities, but is not limited thereto. In view of the above, the new RAT system including 6G may consider using the terahertz (THz) band, i.e., a frequency higher than the NR system, for wider bandwidth and higher transmission speed. The RAT system including 6G may overcome existing limitations by applying artificial intelligence / machine learning (AI / ML), but may not be limited thereto.

[0068] Figure 1 The structure of a wireless communication system to which the present disclosure can be applied is illustrated. Figure 1 , NG-RAN consists of gNBs that provide control plane (RRC) protocol terminations for the NG-Radio Access (NG-RA) user plane (i.e., new access stratum (AS) sublayer / packet data convergence protocol (PDCP) / radio link control (RLC) / MAC / PHY) and UE. The gNBs are interconnected through the Xn interface. In addition, the gNBs are connected to the new generation core (NGC) through the N2 interface. More specifically, the gNB is connected to the access and mobility management function (AMF) through the N2 interface and to the user plane function (UPF) through the N3 interface. Figure 1 It can be based on the structure of the NR system. Figure 1 The structure can be used in the 6G system as it is or by being partially modified, and is not limited to a specific form.

[0069] Figure 2 An example of a wireless device suitable for use with the present disclosure is shown.

[0070] refer to Figure 2The wireless device 200 may send / receive radio signals via various wireless access technologies (e.g., LTE, LTE-A, pre-LTE-A, NR, 5G, 5G-A, 6G). The wireless device 200 may include at least one processor 202 and at least one memory 204, and may further include at least one transceiver 206 and / or at least one antenna 208.

[0071] The processor 202 may be configured to control the memory 204 and / or the transceiver 206 and implement the description, function, process, proposal, method and / or operation flow chart disclosed in this document. For example, the processor 202 may generate a first information / signal by processing the information in the memory 204, and then send a radio signal including the first information / signal through the transceiver 206. In addition, the processor 202 may receive a radio signal including a second information / signal through the transceiver 206, and then store information obtained from the signal processing of the second information / signal in the memory 204. The memory 204 may be connected to the processor 202 and store various information associated with the operation of the processor 202. For example, the memory 204 may store software code including instructions for implementing part or all of the processes controlled by the processor 202 or for implementing the description, function, process, proposal, method and / or operation flow chart disclosed in this document. Here, the processor 202 and the memory 204 may be part of a communication modem / circuit / chip designed to implement wireless communication technology. The transceiver 206 may be connected to the processor 202 and transmit and / or receive radio signals through at least one antenna 208. The transceiver 206 may be a transmitter and / or a receiver. The transceiver 206 may be used interchangeably with a radio frequency (RF) unit. In the present disclosure, a wireless device may refer to a communication modem / circuit / chip.

[0072] Hereinafter, the hardware elements of the wireless device 200 will be described in further detail. Although not limited thereto, at least one processor 202 may implement at least one protocol layer (e.g., functional layers such as physical (PHY), medium access control (MAC), radio link control (RLC), packet data convergence protocol (PDCP), radio resource control (RRC), and service data adaptation protocol (SDAP)). At least one processor 202 may generate at least one protocol data unit (PDU) and / or at least one service data unit (SDU) according to the description, function, process, proposal, method, and / or operation flow chart disclosed in this document. At least one processor 202 may generate a message, control information, data, or information according to the description, function, process, proposal, method, and / or operation flow chart disclosed in this document. At least one processor 202 may generate a signal (e.g., a baseband signal) including a PDU, SDU, message, control information, data, or information according to the function, process, proposal, and / or method disclosed in this document, and provide the signal to at least one transceiver 206. At least one processor 202 may receive a signal (eg, a baseband signal) from at least one transceiver 206 and obtain a PDU, SDU, message, control information, data, or information according to the descriptions, functions, processes, proposals, methods, and / or operational flow charts disclosed in this document.

[0073] At least one processor 202 may be referred to as a controller, a microcontroller, a microprocessor, or a microcomputer. At least one processor 202 may be implemented by hardware, firmware, software, or a combination thereof. As an example, at least one application specific integrated circuit (ASIC), at least one digital signal processor (DSP), at least one digital signal processing device (DSPD), at least one programmable logic device (PLD), or at least one field programmable gate array (FPGA) may be included in at least one processor 202. The description, functions, processes, proposals, methods, and / or operational flowcharts disclosed in this document may be implemented using firmware or software, and the firmware or software may be implemented to include modules, processes, or functions. Firmware or software configured to execute the description, functions, processes, proposals, methods, and / or operational flowcharts disclosed in this document may be included in at least one processor 202, or may be stored in at least one memory 204 and executed by at least one processor 202. The description, functions, processes, proposals, methods, and / or operational flowcharts disclosed in this document may be implemented using firmware or software in the form of code, instructions, and / or instruction sets.

[0074] At least one memory 204 may be connected to at least one processor 202 and store various forms of data, signals, messages, information, programs, codes, instructions, and / or instructions. At least one memory 204 may be configured as a read-only memory (ROM), a random access memory (RAM), an erasable programmable read-only memory (EPROM), a flash memory, a hard disk, a register, a cache memory, a computer-readable storage medium, and / or a combination thereof. At least one memory 204 may be located inside and / or outside of at least one processor 202. In addition, at least one memory 204 may be connected to at least one processor 202 via various technologies such as a wired or wireless connection.

[0075] At least one transceiver 206 can send user data, control information, and wireless signals / channels mentioned in the method and / or operation flow chart of this document to at least one other device. At least one transceiver 206 can receive user data, control information, and wireless signals / channels mentioned in the description, function, process, proposal, method, and / or operation flow chart disclosed in this document from at least one other device. For example, at least one transceiver 206 can be connected to at least one processor 202 and send and receive radio signals. For example, at least one processor 202 can control at least one transceiver 206 to send user data, control information, or radio signals to at least one other device. In addition, at least one processor 202 can control at least one transceiver 206 to receive user data, control information, or radio signals from at least one other device. In addition, at least one transceiver 206 can be connected to at least one antenna 208, and at least one transceiver 206 can be configured to send and receive user data, control information, and radio signals / channels mentioned in the description, function, process, proposal, method, and / or operation flow chart disclosed in this document through at least one antenna 208. In this document, at least one antenna may be a plurality of physical antennas or a plurality of logical antennas (e.g., antenna ports). At least one transceiver 206 may convert received radio signals / channels from RF band signals to baseband signals in order to facilitate processing of received user data, control information, and radio signals / channels using at least one processor 202. At least one transceiver 206 may convert user data, control information, and radio signals / channels processed using at least one processor 202 from baseband signals to RF band signals. To this end, at least one transceiver 206 may include an (analog) oscillator and / or a filter.

[0076] refer to Figure 2The components of the described wireless device may be referred to by other terms from the functional aspect. For example, the processor 202 may be referred to as a control unit, the transceiver 206 may be referred to as a communication unit, and the memory 204 may be referred to as a storage unit. In some cases, the communication unit may be used to include at least a portion of the processor 202 and the transceiver 206.

[0077] refer to Figure 2 The structure of the wireless device described may be understood as the structure of at least a portion of various devices. As an example, the structure may be at least a portion of various devices (e.g., a robot, a vehicle, an XR device, a handheld device, a home appliance, an IoT device, an AI device / server, etc.). In addition, according to various embodiments, in addition to Figure 2 In addition to the components illustrated in the figure, the device may further include other components.

[0078] For example, the device may be a handheld device such as a smart phone, a smart tablet, a wearable device (e.g., a smart watch, smart glasses), and a handheld computer (e.g., a laptop computer, etc.). In this case, the device may further include at least one of: a power supply unit that supplies power and includes a wired / wireless charging circuit, a battery, etc.; an interface unit that includes at least one port (e.g., an audio input / output port, a video input / output port) for connecting to another device; and an input / output unit that is used to input and output video information / signals, audio information / signals, data, and / or information input from a user.

[0079] For example, the device may be a mobile device such as a mobile robot, a vehicle, a train, a manned / unmanned aerial vehicle (AV), and a ship. In this case, the device may further include at least one of the following: a drive unit including at least one of an engine, a motor, a power train, wheels, brakes, and a steering device of the device; a power supply unit that supplies power and includes a wired / wireless charging circuit, a battery, etc.; a sensor unit that senses state information, environmental information, and user information of the device or the surroundings of the device; an automatic driving unit that performs functions such as route maintenance, speed control, and destination setting; and a position measurement unit that obtains mobile object position information through a global positioning system (GPS) and various sensors.

[0080] For example, the device may be an XR device such as an HMD, a head-up display (HUD) provided in a vehicle, a TV, a smartphone, a wearable device, a home appliance, a digital signage, a vehicle, and a robot. In this case, the device may further include at least one of: a power supply unit that supplies power and includes a wired / wireless charging circuit, a battery, etc.; an input / output unit that obtains control information and data from the outside and outputs a generated XR object; and a sensor unit that senses state information, environmental information, and user information of the device or the surroundings of the device.

[0081] For example, the device may be a robot, which may be classified according to the purpose or field of use as industrial use, medical use, home use, military use, etc. In this case, the device may further include at least one of: a sensor unit that senses state information, environmental information, and user information of the device or the surroundings of the device; and a drive unit that moves robot joints and performs various other physical operations.

[0082] For example, the device may be an AI device such as a TV, a projector, a smartphone, a PC, a laptop, a digital broadcast terminal, a tablet, a wearable device, a set-top box (STB), a radio, a washing machine, a refrigerator, a digital signage, a robot, and a vehicle. In this case, the device may further include at least one of: an input unit that obtains various types of data from the outside; an output unit that generates an output associated with vision, hearing, or touch; a sensor unit that senses state information, environmental information, and user information of the device or the surroundings of the device; and a training unit that uses learning data to learn a model composed of an artificial neural network. Figure 2 The structure of the wireless device illustrated in the example can be understood as a part of a RAN node (eg, a base station, a DU, a RU, a RRH, etc.). That is, Figure 2 The device illustrated in the example may be a RAN node. In this case, the device may further include a wired transceiver for fronthaul and / or backhaul communication. However, in the case where the fronthaul and / or backhaul communication is based on wireless communication, Figure 2 The at least one transceiver 206 illustrated in FIG. 2 may be used for fronthaul and / or backhaul communications and may not include a wired transceiver.

[0083] Figure 3 A frame structure in a wireless communication system to which the present disclosure can be applied is illustrated.

[0084] The NR system may support multiple parameter sets. Here, the parameter set may be defined by subcarrier spacing and cyclic prefix (CP) overhead. Here, multiple subcarrier spacings may be derived by scaling the default (reference) subcarrier spacing by an integer N (or μ). In addition, although it is assumed that very low subcarrier spacing is not used in very high carrier frequencies, the parameter set used herein may be selected independently of the frequency band. In addition, various frame structures according to multiple parameter sets may be supported in the NR system.

[0085] In the following, OFDM parameter sets and frame structures that can be considered in the NR system will be described. The various OFDM parameter sets supported in the NR system can be defined as shown in Table 1 below.

[0086] [Table 1]

[0087]

[0088] NR supports multiple parameter sets (or subcarrier spacing (SCS)) to support various 5G services. For example, when the SCS is 15kHz, it supports wide areas of traditional cellular bands, and when the SCS is 30kHz / 60kHz, it supports dense urban areas, lower latency and wider carrier bandwidth, and when the SCS is 60kHz or higher, it supports bandwidth greater than 24.25GHz to overcome phase noise.

[0089] The NR frequency band is defined as two types (FR1, FR2) of frequency ranges. FR1 and FR2 can be configured as shown in Table 2 below. In addition, FR2 may mean millimeter wave (mmW).

[0090] [Table 2]

[0091]

[0092] Regarding the frame structure in the NR system, the sizes of various fields in the time domain are Here, 480·10 3 Hz, and is 4096. Downlink and uplink transmissions are configured (organized) with =10ms duration radio frame. Here, the radio frames are respectively configured with = 10 subframes of duration 1ms. In this case, there is one set of frames for uplink and one set of subframes for downlink. In addition, the transmission in uplink frame number i from the terminal should start earlier than the corresponding downlink frame in the corresponding terminal. For the subcarrier spacing configuration μ, the time slots in the subframe are ∈ The time slots in a radio frame are numbered in ascending order of ∈ A time slot is configured with A continuous OFDM symbol configuration is determined based on the CP . Time slot in subframe The start time is the same as the OFDM symbol in the same subframe It is impossible for all terminals to perform transmission and reception at the same time, which means that not all OFDM symbols of a downlink time slot or an uplink time slot are available.

[0093] Table 3 shows the number of OFDM symbols per time slot in a normal CP ( ), the number of time slots per radio frame ( ) and the number of time slots per subframe ( ), and Table 4 represents the number of OFDM symbols per slot, the number of slots per radio frame, and the number of slots per subframe in the extended CP.

[0094] [Table 3]

[0095]

[0096] [Table 4]

[0097]

[0098] Figure 3 It is an example about μ=2 (SCS is 60 kHz), and referring to Table 3, 1 subframe may include 4 slots. Figure 3 1 subframe = {1, 2, 4} slots shown in is an example, and the number of slots that may be included in 1 subframe is as defined in Table 3 or Table 4. In addition, a mini-slot may include 2, 4, or 7 symbols or more or less symbols.

[0099] Regarding the physical resources in the NR system, antenna ports, resource grids, resource elements, resource blocks, carrier parts, etc. can be considered. Hereinafter, the physical resources that can be considered in the NR system will be described in detail.

[0100] First, with respect to antenna ports, antenna ports are defined so that a channel carrying a symbol in an antenna port can be inferred from a channel carrying another symbol in the same antenna port. When large-scale characteristics of a channel carrying a symbol in one antenna port can be inferred from a channel carrying a symbol in another antenna port, the two antenna ports can be said to be in a quasi-co-located or quasi-co-sited (QC / QCL) relationship. In this case, the large-scale characteristics include one or more of delay spread, Doppler spread, frequency offset, average received power, and receive timing.

[0101] In the 6G system, communication can be performed at the above-mentioned THz frequency band higher than the millimeter wave (mmW) frequency, and the same Figure 3 The same frame structure as shown, or a separate frame structure for the 6G system may be used, but is not limited to a specific form.

[0102] Figure 4 A resource grid in a wireless communication system to which the present disclosure may be applied is illustrated.

[0103] refer to Figure 4 , as an illustrative description, the resource grid is configured in the frequency domain with subcarriers, and one subframe is configured with 14·2 μ OFDM symbols, but the resource grid and subframe are not limited to this. In the NR system, the transmitted signal consists of OFDM symbols and One or more resource grids for each subcarrier. Here, ≤ . represents the maximum transmission bandwidth, which may differ between uplink and downlink and between parameter sets. In this case, one resource grid can be configured for each μ and antenna port p. Each element of the resource grid for μ and antenna port p is called a resource element and is uniquely identified by an index pair (k, l'). Here, k = 0, ..., is an index in the frequency domain, and l'=0,..., refers to the position of a symbol in a subframe. When referring to a resource element in a slot, an index pair (k, l) is used. Here, l = 0, ..., The resource element (k, l') for μ and antenna port p corresponds to the complex value When there is no risk of confusion or no specific antenna port or parameter set is specified, the indices p and μ can be discarded and the complex value can be or In addition, a resource block (RB) is defined as =12 consecutive subcarriers.

[0104] Point A plays the role of a common reference point for the resource block grid and is obtained as follows.

[0105] -OffsetToPointA for the primary cell (PCell) downlink represents the frequency offset between point A and the lowest subcarrier of the lowest resource block overlapping with the SS / PBCH block used by the terminal for initial cell selection. It is expressed in resource blocks, assuming a subcarrier spacing of 15kHz for FR1 and 60kHz for FR2.

[0106] - absoluteFrequencyPointA represents the frequency position of point A, as expressed in terms of an absolute radio frequency channel number (ARFCN).

[0107] For subcarrier spacing configuration μ, the common resource blocks are numbered from 0 upwards in the frequency domain. The center of subcarrier 0 of common resource block 0 for subcarrier spacing configuration μ is the same as "point A". Number of common resource blocks for subcarrier spacing configuration μ in the frequency domain The relationship between and resource element (k, l) is given by the following equation 1.

[0108] [Equation 1]

[0109]

[0110] In Equation 1, k is defined relative to point A, so that k = 0 corresponds to a subcarrier centered at point A. Physical resource blocks are spaced from 0 to 1 in a bandwidth part (BWP). The physical resource blocks in BWP i are and common resource blocks The relationship between is given by the following equation 2.

[0111] [Equation 2]

[0112]

[0113] , is the common resource block where BWP starts relative to common resource block 0.

[0114] Figure 5 The physical resource blocks in the wireless communication system to which the present disclosure can be applied are illustrated. Figure 6 The following illustrates a time slot structure in a wireless communication system to which the present disclosure can be applied.

[0115] refer to Figure 5 and Figure 6 , a slot includes a plurality of symbols in the time domain. For example, for a normal CP, a slot includes 7 symbols, but for an extended CP, a slot includes 6 symbols.

[0116] A carrier includes multiple subcarriers in the frequency domain. A resource block (RB) is defined as multiple (e.g., 12) consecutive subcarriers in the frequency domain. A bandwidth part (BWP) is defined as multiple consecutive (physical) resource blocks in the frequency domain and may correspond to one parameter set (e.g., SCS, CP length, etc.). A carrier may include up to N (e.g., 5) BWPs. Data communication may be performed through activated BWPs, and only one BWP may be activated for one terminal. In a resource grid, each element is called a resource element (RE) and may map one complex symbol.

[0117] In the NR system, each component carrier (CC) can support up to 400MHz. If the terminal working in such a wideband CC always operates with the radio frequency (FR) chip for the entire CC turned on, the terminal battery consumption may increase. Alternatively, when considering several application scenarios (e.g., eMBB, URLLC, Mmtc, V2X, etc.) operating in one wideband CC, different parameter sets (e.g., subcarrier spacing, etc.) can be supported in each frequency band in the corresponding CC. Alternatively, each terminal may have a different maximum bandwidth capability. In this regard, the base station may instruct the terminal to operate only in part of the bandwidth instead of the total bandwidth of the wideband CC, and for convenience, the corresponding part of the bandwidth is defined as a bandwidth part (BWP). BWP can be configured with continuous RBs on the frequency axis and can correspond to a parameter set (e.g., subcarrier spacing, CP length, slot / microslot duration).

[0118] At the same time, even in one CC configured for the terminal, the base station can configure multiple BWPs. For example, a BWP occupying a relatively small frequency domain can be configured in the PDCCH monitoring time slot, and the PDSCH indicated by the PDCCH can be scheduled in a larger BWP. Alternatively, when the UE is congested in a specific BWP, some terminals can be configured with another BWP for load balancing. Alternatively, considering the frequency domain inter-cell interference elimination between adjacent cells, etc., some middle spectrum of the entire bandwidth can be excluded, and the BWP on both edges can be configured in the same time slot. In other words, the base station can configure at least one DL / UL BWP for the terminal associated with the broadband CC. The base station can activate at least one DL / UL BWP in the configured DL / UL BWP at a specific time (through L1 signaling or MAC control unit (CE) or RRC signaling, etc.). In addition, the base station can indicate switching to another configured DL / UL BWP (through L1 signaling or MAC CE or RRC signaling, etc.). Alternatively, based on a timer, when the timer value expires, it can switch to the determined DL / UL BWP. Here, the activated DL / UL BWP is defined as the active DL / UL BWP. However, when the terminal performs the initial access process or has not yet established an RRC connection, the configuration of the DL / UL BWP may not be received, so the DL / UL BWP assumed by the terminal in this case is defined as the initial active DL / UL BWP.

[0119] Figure 7 A physical channel used in a wireless communication system to which the present disclosure can be applied and a general signal transmission and reception method using the physical channel are illustrated.

[0120] In a wireless communication system, a terminal receives information from a base station via a downlink, and a terminal sends information to a base station via an uplink. The information sent and received by the base station and the terminal includes data and various control information, and there are various physical channels according to the type / purpose of the information they send and receive.

[0121] When the terminal is turned on or newly enters a cell, the terminal performs an initial cell search, which includes synchronization with a base station (S701). To this end, the terminal can synchronize with the base station by receiving a primary synchronization signal (PSS) and a secondary synchronization signal (SSS) from the base station, and obtain information such as a cell identifier (ID). Next, the terminal can obtain broadcast information in the cell by receiving a physical broadcast channel (PBCH) from the base station. At the same time, the terminal can check the downlink channel status by receiving a downlink reference signal (DL RS) in the initial cell search step.

[0122] The terminal that has completed the initial cell search may obtain more detailed system information by receiving a physical downlink control channel (PDCCH) and a physical downlink shared channel (PDSCH) according to information carried in the PDCCH (S702).

[0123] Meanwhile, if the terminal accesses the base station for the first time or does not have radio resources for signal transmission, the terminal may perform a random access procedure (RACH) on the base station (S703 to S706). To this end, the terminal may send a specific sequence as a preamble through a physical random access channel (PRACH) (S703 and S705), and receive a response message to the preamble through a PDCCH and a corresponding PDSCH (S704 and S706). In the case of a contention-based RACH, a contention resolution process may be additionally performed.

[0124] The terminal having performed the above process may then perform PDCCH / PDSCH reception (S707) and physical uplink shared channel (PUSCH) / physical uplink control channel (PUCCH) transmission (S708) as a general uplink / downlink signal transmission process. Specifically, the terminal receives downlink control information (DCI) through PDCCH. Here, DCI includes control information such as resource allocation information for the terminal, and has different formats depending on its purpose of use.

[0125] At the same time, the control information sent by the terminal to the base station through the uplink or received by the terminal from the base station includes downlink / uplink confirmation / non-confirmation (ACK / NACK) signal, channel quality indicator (CQI), precoding matrix indicator (PMI), rank indicator (RI), etc. For the 3GPP LTE system, the terminal can send the above-mentioned CQI / PMI / RI and other control information through PUSCH and / or PUCCH.

[0126] Specific embodiments of the present disclosure

[0127] Hereinafter, the present disclosure describes a technology for simultaneously controlling multiple cells using a single physical downlink control channel (PDCCH) in a base station supporting carrier aggregation (CA). Specifically, the present disclosure describes various embodiments in which a base station controls the scheduling of data transmission of a physical downlink shared channel (PDSCH) for multiple cells through a single PDCCH. The multiple cells may include at least one of a primary cell (Pcell), a secondary cell (Scell), a secondary-secondary cell (secondary Scell ​​or sScell), or a primary-secondary cell (primary Scell ​​or pScell).

[0128] 5G NR (New Radio) is a technology that provides services mainly through major technologies such as eMBB (enhanced mobile broadband), URLLC (ultra-reliable low latency communication), and mMTC (massive machine type communication). eMBB is a technology that focuses mainly on speed improvement and transmits a large amount of information by extending the spectrum from LTE (Long Term Evolution). eMBB is an important frequency aggregation technology widely used in 5GNR.

[0129] Currently, 5G NR is based on the principle that the PDCCH of a cell performs scheduling on the PDSCH responsible for data transmission for the cell on a cell-by-cell basis. That is, the base station generally has to perform scheduling once through the PDCCH to trigger a PDSCH transmission. In addition, in the case of carrier aggregation, that is, in the case of sending PDSCH through multiple cells to improve data throughput from the perspective of eMBB, the base station has to notify the terminal of scheduling information through the PDCCH for each cell for simultaneous transmission of PDSCH through multiple cells. This is the basic operation performed since 4G LTE.

[0130] However, as the number of frequency bands that can be supported in 5G NR increases, the number of cells used for carrier aggregation in 5G NR may be greater than the number of cells used for carrier aggregation in LTE. Therefore, if the existing method of performing scheduling on a cell-by-cell basis through PDCCH in 5G NR is applied without change, the terminal consumes a large amount of resources to decode the scheduling information. Therefore, if the existing method of performing scheduling on a cell-by-cell basis through PDCCH in 5G NR is applied without change, the terminal consumes a large amount of resources to decode the scheduling information.

[0131] Therefore, the present disclosure proposes a method for performing PDSCH scheduling of multiple cells using a single PDCCH in one cell. Specifically, the present disclosure proposes a technology for indicating frequency allocation of PDSCHs of multiple cells in a single PDCCH information of a specific cell, so as to send PDSCH scheduling information of multiple cells to a terminal.

[0132] FDRA (Frequency Domain Resource Allocation) indicating frequency allocation within PDCCH is the field that uses the most bits among various fields in PDCCH. Therefore, when indicating frequency allocation to multiple cells, as many bits as a multiple of the multiple cells are used, which may lead to the problem of excessive increase in the amount of information of PDCCH. Currently, the minimum transmission payload of PDCCH is 140 bits, but because the minimum transmission payload of PDCCH in 5G NR is greater than 140 bits, it is impossible to operate FDRA for multiple cells in principle. Therefore, for multiple cells, L2 MAC (Media Access Control) CE (Control Element) with less restrictions on payload size can be utilized instead of using as many bits as a multiple of the multiple cells in a single PDCCH. Alternatively, it is possible to send FDRA information indication to multiple cells to the terminal in a manner that minimizes the increase in the number of bits in one FDRA by sharing common features within the existing Layer 1 PDCCH. Therefore, it is expected to solve the performance degradation problem caused by PDCCH decoding of the terminal in eMBB and increase the availability of resource elements.

[0133] Hereinafter, the present disclosure describes a method for performing simultaneous scheduling of PDSCH transmissions of multiple cells using a single PDCCH for a specific cell in a carrier aggregation situation. Specifically, the present disclosure will describe a method for expressing FDRA information of multiple cells using a small amount of information or a small amount of bits by utilizing a commonly sharable feature, instead of using an amount of information or a number of bits that is a multiple of the cells for frequency allocation related information called FDRA in the PDCCH. That is, the present disclosure will describe a method for indicating an FDRA field to express FDRA information for multiple cells in a single PDCCH.

[0134] Typically, the size of FDRA is about 14 to 18 bits, and the size of FDRA may vary depending on the frequency band or bandwidth. When the size of FDRA is 18 bits, in a carrier aggregation scenario, when FDRA is used in one PDCCH to allocate frequencies for multiple cells, a number of bits (e.g., 72 bits) corresponding to 18 bits × the number of scheduled cells (e.g., 4 CCs (component carriers)) is required. In this case, a situation may arise in which the FDRA field, as one of dozens of fields transmitted through the PDCCH, occupies about 50% or more of the total available payload size of 140 bits of the PDCCH. Therefore, it may not be possible to schedule the PDSCHs of multiple cells in a single PDCCH in a manner using the existing FDRA. Therefore, the present disclosure will propose various techniques that enable PDSCH scheduling for multiple cells (e.g., 4 CCs) using much fewer bits than the aforementioned number of bits. In the proposed technology, depending on which method is selectively applicable relative to FDRA, it is possible to distinguish how the DCI (downlink control information) field information of the PDCCH is applied to the scheduled CC.

[0135] [Table 5] shows the characteristics of the fields in the PDCCH for multi-CC scheduling. [Table 5] shows seven processing methods.

[0136] [Table 5]

[0137]

[0138] Hereinafter, the present disclosure proposes various option methods using the following processing methods for the FDRA field among several fields in the PDCCH.

[0139] 1) Option 1: Shared - Public

[0140] -Method of applying one FDRA information to multiple CCs or cells

[0141] 2) Option 2: Single - Incremental

[0142] - Bitmap (resource allocation type 0): A method of adding or subtracting some RBGs (resource block groups) based on reference information

[0143] -RIV (Resource Indication Value) (Resource Allocation Type 1): A method for indicating the difference in RIV length value based on reference information

[0144] 3) Option 3: Separate - Equal

[0145] - A method to determine the FDRA size based on the number of scheduled CCs (component carriers or cells).

[0146] 4) Option -4: Omit

[0147] In the present disclosure, in order to reduce the DCI overhead required for scheduling PDSCH and / or PUSCH (Physical Downlink Shared Channel) in a carrier aggregation scenario in which multiple cells are configured, a multi-cell scheduling method for simultaneously scheduling multiple serving cells and / or CCs and PDSCH / PUSCH transmissions through them using a single DCI may be considered based on a reasonable interpretation as shown in the following Table 6 of Release 18.

[0148] [Table 6]

[0149]

[0150] Hereinafter, the present disclosure describes various embodiments for the configuration and interpretation of the FDRA field in DCI, for performing the structural design of DCI for multi-cell scheduling as described above, that is, MC-DCI (multi-cell DCI). The multi-cell scheduling operation for PDSCH transmission or PUSCH transmission described in the present disclosure may be applied identically or similarly to multi-cell scheduling for PUSCH transmission or PDSCH transmission, respectively. In addition, in the present disclosure, CC (component carrier) may be understood as an active bandwidth part (active BWP), a cell, etc., set and / or indicated to a CC. In the present disclosure, a scheduled CC may be referred to as a co-scheduled CC. In addition, in the present disclosure, when cell grouping is performed on multiple cells included in a scheduled CC, one group may be referred to as a cell subgroup.

[0151] Hereinafter, the present disclosure proposes several options for enabling PDSCH scheduling for multiple CCs by effectively utilizing the minimum number of bits without adding a DCI field for PDCCH for multi-carrier scheduling through multiple CCs in the DCI field structure of the traditional PDCCH where the FDRA field of each CC occupies 13 to 18 bits. In this case, the following multiple basic operations can be assumed. The basic operations according to various embodiments of the present disclosure are as follows.

[0152] A. Determining a group of CCs, i.e., a subset, that will share information of FDRA may be implemented at a higher layer (e.g., RRC layer or MAC layer). For example, a group of CCs may be determined by intra-band CCs, inter-band CCs, the same subcarrier spacing (SCS), or resource allocation (RA) type.

[0153] B. For multiple options, the basic information of the shared FDRA can be provided semi-statically from the MAC layer and can be pre-configured in the RRC layer. In addition, DCI can be used to indicate incremental information or additional information of this information.

[0154] C. In the present disclosure, in principle, the maximum number of CCs that can be scheduled simultaneously is not limited. However, hereinafter, for the convenience of description, the present disclosure assumes that the maximum number of CCs is 4. However, even when the number of CCs is 4 or more, the present disclosure can be equally applied. In addition, the maximum number of CCs that can be scheduled for downlink and uplink is the same.

[0155] D. If the base station is operable, the base station may inform the terminal which options to use depending on the situation through RRC signaling. Therefore, if the number of CCs is dozens, the base station may consider grouping CCs per option.

[0156] E. In the present disclosure, the entire bandwidth of a CC may be used as an RB or an RBG, but if a BWP (bandwidth part) is set, the RB or RBG may be used within the corresponding BWP range.

[0157] F. In the present disclosure, CIF may be mainly used to indicate the validity of a cell or a cell group or the number of cells. In the present disclosure, a separate field named XXX may be defined based on CIF, and the size of the field may be 3 bits or more. In the present disclosure, the validity of a cell or a cell group is related to whether resources are allocated to the cell or the cell group through MC-DCI, and the state of resource allocation may be expressed as valid. In addition, in the present disclosure, the state in which resources are allocated may be expressed as an "actually scheduled" state.

[0158] 1. Option-1: Shared-common FDRA bit information configuration

[0159] The shared-common FDRA bit information configuration method is a method of applying the FDRA information and / or value indicated by one FDRA field to multiple cells in common by configuring only one FDRA field in DCI for multiple cells scheduled by the same MC-DCI. In this way, when multiple carriers or cells share the same FDRA field, that is, the FDRA information and / or the value indicated by the FDRA field, the FDRA field and / or the FDRA information can be configured and / or indicated by considering the different bandwidths and / or different subcarrier spacings (SCS) of the multiple cells. For example, the information of the FDRA field can be configured and / or indicated based on the number of RBs (G) of the cell with the maximum or minimum number of RBs (G) among the scheduled CCs, or based on the number of RBs (G) of a specific reference cell. In the present disclosure, RB (G) means RB (resource block) or RBG (resource block group). That is, the criterion for determining the maximum / minimum bandwidth can be the number of RBs or the number of RBGs in the BWP of each CC that is actually scheduled and determined based on the SCS, rather than the size of the BWP. Based on the shared-common FDRA bit information configuration method, the FDRA field in the MC-DCI can be configured for each cell subgroup belonging to the co-scheduled cell set. That is, an FDRA field is configured for each cell subgroup, and the value indicated by the FDRA field can be commonly applied to the cells belonging to the corresponding cell subgroup. At this time, the FDRA field and / or FDRA information for each cell subgroup can be configured and / or indicated based on the cell with the maximum number of RBs (G), the cell with the minimum number of RBs (G), or a specific reference cell among the cells belonging to the corresponding cell subgroup, the co-scheduled cell set to which the cell subgroup belongs, or the number or size of RBs (G) of the cells in the entire scheduled cell set.

[0160] According to one embodiment of the present disclosure, if a specific reference cell is determined and / or set in each cell subgroup or co-scheduled cell set, the reference cell changes at each scheduling time point. In this case, adaptive and / or efficient resource allocation can be achieved, but the complexity of the terminal that must reconfigure and reinterpret the FDRA field and / or information and match the retransmission TB size may increase.

[0161] According to one embodiment of the present disclosure, if a specific reference cell is determined and / or set within the entire set of scheduled cells, the reference cell is fixed and does not change at each scheduling time point. In this case, the efficiency of resource allocation will be reduced, but because the configuration and interpretation of the FDRA field and / or information are the same and it is easy to match the retransmission TB size, the increase in terminal complexity can be minimized.

[0162] According to one embodiment of the present disclosure, if only one cell is scheduled via MC-DCI, one cell is exceptionally determined as a reference cell. In this case, the FDRA field and / or FDRA information may be configured and / or indicated based on the number and / or size of RB(G) set for the corresponding cell.

[0163] According to one embodiment of the present disclosure, if the FDRA information indicated for a specific cell subgroup via MC-DCI is invalid, the terminal may operate in a state where it is considered or assumed that there is no scheduling information of all cells belonging to the corresponding cell subgroup to perform PDSCH / PUSCH transmission and reception. The case where the FDRA information is invalid may include a case where all bits of the bitmap are indicated as "0", or a case where all bits of the RIV are indicated as 1.

[0164] 1-1. Cell-based FDRA method with maximum number of RB(G) based on BWP

[0165] The FDRA field and / or FDRA information may be configured and / or indicated based on the maximum number N_max of RBs (G) set for a cell scheduled by the same MC-DCI. For example, if the number of RBs (G) on a specific reference cell is the maximum value among the number of RBs (G) of a cell scheduled by the same MC-DCI, the FDRA field and / or FDRA information may be configured and / or indicated based on the number and / or size of RBs (G) set for the specific reference cell. Here, a cell scheduled by the same MC-DCI may mean a cell belonging to a co-scheduled cell set, a cell subgroup belonging to a co-scheduled cell set, or the entire scheduled cell set. At this time, for a cell in which N_less (which is less than N_max) RBs (G) are set, the first N_less RBs (G) index indications and / or allocated RB (G) allocation information among the RBs (G) indicated by the FDRA field may be used as information about the N_less RB (G) index region of the corresponding cell. That is, when the FDRA field indicating whether RBs (G) indexed 0 to N_max-1 are allocated is applied to a cell set having N_less RBs (G), information about RBs (G) indexed 0 to N_less-1 is used, and information about RBs (G) indexed N_less to N_max-1 is not used. For ease of explanation, the method of configuring the FDRA field and / or FDRA information based on the maximum number N_max of RBs (G) as described above may be referred to as "FDRA based on the maximum number of RBs (G), or FDRA based on the maximum value".

[0166] Figure 8 An example of a FDRA method based on the maximum number of RBs (G) in a wireless communication system according to an embodiment of the present disclosure is illustrated. For ease of explanation, Figure 8 The figure shows a case where two CCs are included in one cell subgroup. Figure 8 The FDRA method based on the maximum number of RB(G) described in may also be applied to a case where three or more CCs are included in a cell subgroup.

[0167] refer to Figure 8 , CC1 801 and CC2 802 may be set to a cell subgroup scheduled by the same MC-DCI. Figure 8 In the example, since the number of RBGs of CC1 801 is greater than the number of RBGs of CC2 802, the FDRA field and / or FDRA information may be configured based on the number or size of RBGs of CC1 801. For example, the information of the FDRA field may indicate only information about CC1 801. At this time, for frequency resource allocation for CC2 801, no additional bit allocation is required in the FDRA field, and the value of the lower-indexed RBG among the information about CC1 801 may be reused. In this way, when the FDRA information configured based on the maximum number N_max of RBs (G) is reused in another CC within a cell subgroup, the cell subgroup may be set by a higher RRC layer or MAC layer, or may be changed semi-statically.

[0168] 1-2. Cell-based FDRA method with minimum number of RB(G) based on BWP

[0169] The FDRA field and / or FDRA information may be configured and / or indicated based on the minimum number N_min of RBs (G) set for a cell scheduled by the same MC-DCI. For example, if the number of RBs (G) set for a specific reference cell is the minimum value among the number of RBs (G) of cells scheduled by the same MC-DCI, the FDRA field and / or FDRA information may be configured and / or indicated based on the number and / or size of RBs (G) set for the reference cell. Here, the cell scheduled by the same MC-DCI may mean a cell belonging to a co-scheduled cell set, a cell subgroup belonging to a co-scheduled cell set, or the entire scheduled cell set. At this time, for a cell that sets N_more (which is greater than N_min) RBs (G), the FDRA information indicated by the FDRA field, that is, information about at least one RB (G) indicated and / or allocated for an area indexed by N_miN RBs (G), may be applied to an index area of ​​N_miN RBs (G) among N_more RBs (G). At this time, it can be interpreted as omitting resource allocation for some remaining RBs (G) (i.e., N_more-N_miN RBs (G)) of the corresponding cell. For ease of explanation, the above method of configuring the FDRA field and / or FDRA information based on the minimum number N_min of RBs (G) can be referred to as "FDRA based on the minimum number of RBs (G) or FDRA based on the minimum value".

[0170] Fig. 9 An example of an FDRA method based on the minimum number of RBs (G) in a wireless communication system according to an embodiment of the present disclosure is illustrated. For ease of explanation, Fig. 9 The case where two CCs are included in one cell subgroup is shown. Fig. 9 The FDRA method based on the minimum number of RB(G) described in may also be applied to a case where three or more CCs are included in a cell subgroup.

[0171] refer to Fig. 9 , CC1 901 and CC2 902 may be set to a cell subgroup scheduled by the same MC-DCI. Fig. 9 In the example, since the number of RBGs of CC2 902 is less than the number of RBGs of CC1 801, the FDRA field and / or FDRA information may be configured based on the number or size of RBGs of CC2 802. In this case, RBG4 and RBG5 of CC1 901 are not indicated by the FDRA field. Therefore, according to various embodiments, whether to allocate RBG4 and RBG5 may be indicated based on one of the following methods.

[0172] A. It may be determined that RBG4 and RBG5 are not used in CC1. This can lead to an advantage of operating a DCI field of a PDCCH having a minimum number of bits.

[0173] B. Whether to use RBG4 and RBG5 can be determined in advance by reconfiguration of the RRC layer or in a semi-static manner in the MAC layer. Compared with the aforementioned method A, this provides an effect of improving frequency utilization.

[0174] C. The terminal may determine whether to use RBG4 and RBG5 by referring to whether RBGs (eg, RBG2, RBG3) with lower indexes than RBG4 and RBG5 are used. That is, by estimating whether to use RBG4 and RBG5 based on the similarity of adjacent channels, the utilization of RBG4 and RBG5 can be improved.

[0175] According to one embodiment of the present disclosure, the FDRA field and / or FDRA information may be configured and / or indicated based on the number of RBs (G) N_mid among the number of RBs (G) set for the cell scheduled by the same MC-DCI, not the maximum number of RBs (G) N_max and the minimum number of RBs (G) N_min. For example, the FDRA field and / or FDRA information may be configured and / or indicated based on the number and / or size of RBs (G) set for a specific reference cell. Here, the cell scheduled by the same MC-DCI may mean a cell belonging to a co-scheduled cell set, a cell subgroup belonging to a co-scheduled cell set, or the entire scheduled cell set. For cells having a number of set RBs (G) less than N_mid, the above-mentioned maximum value-based FDRA method may be applied, while for cells having a number of set RBs (G) greater than N_mid, a minimum value-based FDRA method may be applied.

[0176] As described above, when the FDRA field is configured based on the cell with the smallest RB(G) or the largest RB(G), it can be as follows Fig.10 The illustrated diagram shows that cells are grouped based on N_min or N_max in MAC CE or RRC. The base station can perform multi-carrier scheduling based on the group. At this time, it can be determined in a higher layer of the base station whether to group cells based on N_min or based on N_max.

[0177] Fig.10 An example of a method for configuring shared-common FDRA bit information in a wireless communication system according to an embodiment of the present disclosure is illustrated. Fig.10, N_max group 1 1010 includes Pcell, Scell ​​5 and Scell ​​1, N_min group 2 1020 includes Scell ​​2, Scell ​​3 and Scell ​​4, and N_max group 3 1030 includes Scell ​​6, Scell ​​7 and Scell ​​8. Fig.10 When a plurality of cells are grouped into a plurality of groups as shown in , a group ID may be added to the FDRA. Therefore, as many FDRA fields as the number of groups may all be included in one PDCCH (ie, MC-DCI). However, when a plurality of cells are grouped into a single group, the group ID may not be included in the FDRA.

[0178] The above-mentioned option-1 may be applied to a resource allocation method using a bitmap of RA (resource allocation) type 0, but is not limited thereto, and may also be applied to a resource allocation method using RIV of RA type 1. For example, when the number of RBs of a plurality of CCs is the same and the frequency characteristics between CCs are similar due to frequency aggregation within a frequency band, option-1 may be applied to the RIV method of RA type 1.

[0179] According to an embodiment of the present disclosure, multiple cell groups or cell subgroups including multiple cells scheduled by the same MC-DCI, i.e., cells that share a single FDRA field together, may be established. In this case, the FDRA field and / or FDRA information may be configured and / or indicated for each cell group or cell subgroup through MC-DCI. In this case, a single cell group may be established to include only cells for which the same RA type is established and / or indicated, and cells for which different RA types are established and / or indicated may be established to belong to different cell groups.

[0180] 1-3. RB(G)-based FDRA method based on reference CC

[0181] The resource allocation method of multiple carriers can be applied based on a designated reference cell instead of the aforementioned maximum bandwidth or minimum bandwidth. According to one embodiment, the scheduled CCs can be grouped by FR (frequency range) or by CCs within a frequency band, and a reference CC can be designated for each group. In this case, the grouping can be based on the configuration of the base station and can be determined in advance without a specific principle.

[0182] If the reference CC specified in the group has N RBs (G), the RA information can refer to a specific RB (G) index in the form of an RB (G) bitmap or RB (G) level RIV for the N RBs (G). In this case, if the RA information is applied to another CC in the group other than the reference CC, it can be interpreted as allocating the same RBG index based on the RBG included in the RA information, or it can be interpreted as allocating the RB index indicated by the RA information.

[0183] According to one embodiment, the reference CC can be implicitly, explicitly, dynamically, statically or semi-statically specified and / or changed in the form of MAC CE, RRC reconfiguration or DCI. According to one embodiment, the reference CC may be predetermined as the CC with the lowest index or the CC with the highest index among the CCs in the group. The reference CC may be a designated CC that representatively provides a specific DCI field and indicates one of the scheduled CCs. If the group includes only one CC, the CC may be designated as the reference CC, and the reference CC may be indicated by the designated RNTI (Radio Network Temporary Identifier) ​​or C-RNTI (Cell RNTI) of the CC. According to one embodiment, MC-RNTI (Multi-cell RNTI) for MC-DCI may be used.

[0184] [Table 7] shows an example of RB(G) configuration of a reference CC within a CC group.

[0185] [Table 7]

[0186]

[0187] [Table 7] shows that when Cell 2 is designated as a reference CC in a CC group including Cell 1, Cell 2, and Cell 3, resources for the CC group are allocated based on RBG size 5. At this time, it is possible to consider using a separate-incremental FDRA method to indicate an index for an RBG. When a single cell is scheduled using MC-DCI, the following two methods can be applied.

[0188] - Method 1: Ignore the FDRA of the indicated reference cell, or indicate the FDRA of a single cell without indicating the reference CC using MC-DCI.

[0189] - Method 2: Even if only one CC is scheduled, the FDRA of the cell is interpreted based on the existing reference CC.

[0190] In addition, in the shared-common FDRA field indication method, the resource allocation information of FDRA can be used as indication information of the cell scheduled using MC-DCI as an indication of the cell group. In other words, the FDRA field provided for each cell group can also be used as validity information, in which case the FDRA field can indicate whether at least one of the cells belonging to the group has been actually scheduled. At this time, if the CIF bit is insufficient, the base station can group CC group 1 and CC group 2 into one group by grouping the cells, and use one CIF value to indicate the configuration related to the CIF. In the case where CC group 1 and CC group 2 are grouped into one group and share one CIF, if scheduling is performed only for CC group 1, the base station can intentionally indicate that the FDRA value of CC group 2 is invalid. For example, the base station can set all bitmap values ​​of FDRA to "0" or set all RIV values ​​of FDRA to "1". This method can be equally applied when the cell consists of one group, or when it is assumed that there is only one group in the scheduled CC. The reference CC can be one of the scheduled CCs or one of the grouped CCs. In this case, each bit of the CIF may be used to indicate the validity of the remaining CCs or CC groups except for the reference CC.

[0191] Option-2: Single-incremental FDRA bit information configuration

[0192] According to the separate-incremental FDRA bit information configuration method, other CCs can refer to increments based on the FDRA bit information of the reference CC. For cells using one MC-DCI group, a separate-incremental FDRA method can be set based on one reference CC, and the application of the separate-incremental method can be set at a higher RRC layer or MAC layer.

[0193] like Fig.11 As shown in the figure, when one PDCCH is used to schedule PDSCHs of multiple cells, the base station may divide the multiple cells or multiple CCs into multiple groups in consideration of frequency characteristics. Fig.11 An example of a cell group for multi-carrier PDCCH scheduling in a wireless communication system according to an embodiment of the present disclosure is illustrated. Fig.11, the cells reversed within CC group 1 1110 and CC group 2 1120 (for example, Scell ​​5 and Scell ​​2) are the reference CCs of the corresponding CC groups. In the case of the aforementioned option 1, the cell with the maximum RB (G) or the minimum RB (G) is set as the reference CC. In the case of option 2, any cell can be a reference CC. In this case, the FDRA information of the corresponding arbitrary cell can be used as the reference FDRA information of the corresponding CC group. Therefore, the base station can indicate only incremental information to other cells in the CC group, and the incremental information indicates the difference from the reference FDRA information. At this time, the group ID, the reference FDRA information, or the incremental information can increase the number of CC groups. If the CC group includes only one cell, the incremental information indicating the difference from the reference FDRA information can be set to the entire FDRA field information of the MC-DCI.

[0194] Compared with Option 1, Option 2 has the disadvantage of increasing the total number of bits related to frequency allocation in PDCCH, that is, the amount of information, but has the advantage of increasing the flexibility of frequency allocation. In other words, Option 2 can make more efficient use of frequency in the case of inter-band carrier aggregation. Fig.12 Describes specific operations based on the reference CC.

[0195] Fig.12 An example of a separate-incremental FDRA information configuration in a wireless communication system according to an embodiment of the present disclosure is illustrated. Fig.12, a reference CC 1109 may be determined for each group. When two RBGs are set in the reference CC 1109, they may be indexed as RBG1, RBG2, RBG3, and RBG4, in sequence. At this time, CC1 1101 further includes RBG5, and CC2 1102 does not include RBG4. The difference in the RGB structure compared with the reference CC 1109 may be indicated by additional information. Additional information indicating the RGB structure compared with the reference CC 1109 may be transmitted in advance from a higher layer. For example, the additional information may have a form such as “LIST{… -2, -1, 0, 1, 2, …}”. If the additional information for the CC is -1, it indicates that the remaining RBGs except RBG4, i.e., RBG1, RBG2, RBG3, are allocated, such as CC2 1102. If the additional information for the CC is 1, this indicates that one more RBG, i.e., RBG5, is allocated in addition to RBG1, RBG2, RBG3, and RBG4, such as CC1 1101. Similarly, if the additional information is -2, this indicates that the remaining RBGs, i.e., RBG1 and RBG2, are allocated in addition to RBG3 and RBG4, and if the additional information is 2, this indicates that RBG5 and RBG6 are further allocated in addition to RBG1, RBG2, RBG3, and RBG4. In this case, the number of additionally allocated RBG units can be variably preconfigured. This operation can be equally applied regardless of whether multiple cells using PDSCH scheduled by one MC-DCI are included in one group or multiple groups.

[0196] In the above description, a method of allocating the frequency of FDRA mainly using the bitmap of RA type 0 is described. Unlike RA type 0, the method of using RIV of RA type 1 allocates frequency by utilizing length and start information. When RA type 1 is applied, for CCs other than the reference CC, an increment can be indicated by the FDRA field, which indicates the difference from the length information of the reference CC. That is, the FDRA field may include an increment value indicating a decrease (e.g., -X or -Y) or an increase (e.g., +X or +Y) in the length information of the reference CC. According to this method, scheduling of multiple cells and carriers in one PDCCH is possible. According to one embodiment, a group ID may be added depending on whether the CC belongs to one group or multiple groups, such as RA type 0. The method of allocating frequency resources using RIV can also be used for the DCI X_2 format of the PDCCH introduced in Release 16. For example, the K2 value determined by a higher layer parameter such as L3 RRC resourceAllocationType1GranularityDCI-1-2 can be applied to all cells or to each group in common.

[0197] Option 3: Single-Equal FDRA Bit Information Configuration

[0198] The size of FDRA can be variably increased or decreased depending on the number of scheduled CCs. When N cells are configured for carrier aggregation, the N cells are not always scheduled simultaneously. That is, the number of CCs scheduled simultaneously may vary depending on the amount of data, channel and / or frequency conditions. In such a case, according to option 3, unlike option 1 and option 2, the number of bits of the FDRA field can be the same regardless of how many cells are scheduled on the current PDCCH. In other words, the number of bits of the FDRA field can be the same when the number of CCs scheduled in a PDCCH is 1 and when it is MAX. In summary, when one CC is scheduled in a PDCCH, the size of the FDRA field for one CC is N bits, and when multiple CCs are scheduled in a PDCCH, the size of the FDRA field is also N bits, and in such a case, the size of the FDRA field for each of the multiple CCs can be M, P, ..., K bits. Here, N>M, P, ..., K, and N=M+P+...+K.

[0199] When the PDSCHs of multiple cells are scheduled in one PDCCH, multiple CCs are not always scheduled equally with the same number of bits. For example, when the number of CCs is 1, the bits of the FDRA field of the CC are 12 bits, and when the number of CCs is 2, the bits of the FDRA field of each CC are 6 bits, but in the bitmap form of RA type 0, the RBG size can be set larger. As another example, when the number of CCs is 3, the number of bits of the FDRA field can be divided into 4 bits and allocated to the CCs, or the bits can be allocated to the CCs differently by assigning weights to each CC, such as 3 bits or 6 bits, according to the size of the BWP. In this case, the weights can be determined as follows.

[0200] (1) The number of bits used for each CC can be determined using 1 CC BWP size / (1 CC BWP size+2 CC BWP size) and 2 CC BWP size / (1 CC BWP size+2 CC BWP size).

[0201] (2) The total number of bits is determined according to the number of CCs, and the number of bits used for each CC can be determined according to a method specified based on the BWP size. In this case, the RBG size can be operated more coarsely.

[0202] Similar to Option-1 and Option-2, the base station can form multiple groups by grouping cells with similar characteristics and add the group ID of each group to the FDRA field. This enables scheduling multiple cells in one PDCCH. However, if the number of groups is 1, the group ID information can be excluded.

[0203] According to one embodiment, in the case of RA type 0, for BWP#A of CC1, "the number of RBs for each RBG during 1-CC scheduling = 3, the number of RBs for each RBG during 2-CC scheduling = 5, and the number of RBs for each RBG during 3-CC scheduling = 10" can be preset; for BWP#B of CC2, "the number of RBs for each RBG during 1-CC scheduling = 5, the number of RBs for each RBG during 2-CC scheduling = 10, and the number of RBs for each RBG during 3-CC scheduling = 15" can be preset; and for BWP#C of CC3, "the number of RBs for each RBG during 1-CC scheduling = 4, the number of RBs for each RBG during 2-CC scheduling = 6, and the number of RBs for each RBG during 3-CC scheduling = 12" can be set. At this time, when MC-DCI is used to schedule {1-CC, 2-CC, 3-CC}, the size of the FDRA field can be determined by the number of bits of the combination with the largest number of bits required for the FDRA field among the combinations of {CC1 only, CC2 only, CC3 only, CC1+CC2, CC1+CC3, CC2+CC3, CC1+CC2+CC3}.

[0204] According to one embodiment, in the case of RA type 1, for BWP#A of CC1, "1-CC scheduling period K2 (RIV granularity) = 1, 2-CC scheduling period K2 = 3, 3-CC scheduling period K2 = 5" may be preset, for BWP#B of CC2, "1-CC scheduling period K2 = 1, 2-CC scheduling period K2 = 2, 3-CC scheduling period K2 = 3" may be preset, and for BWP#C of CC3, "1-CC scheduling period K2 = 2, 2-CC scheduling period K2 = 3, 3-CC scheduling period K2 = 4" may be set. At this time, when {1-CC, 2-CC, 3-CC} is scheduled using MC-DCI, the size of the FDRA field may be determined by the number of bits of the combination of {CC1 only, CC2 only, CC3 only, CC1+CC2, CC1+CC3, CC2+CC3, CC1+CC2+CC3} that requires the most bits for the FDRA field.

[0205] For cells scheduled via MC-DCI, individual FDRA fields and / or FDRA information may be configured and / or indicated for each cell. Hereinafter, for ease of explanation, for cells whose bandwidth is set to N RBs, the RBG size defined and / or set by the existing DCI-based scheduling is referred to as K. Here, the existing DCI-based scheduling means the existing DCI-based scheduling for a single cell, and K is the maximum number of RBs for configuring the corresponding RBG. At this time, when a cell whose bandwidth is set to N RBs is scheduled via MC-DCI, the RBG size corresponding to the corresponding cell may be set to L greater than K. At this time, depending on the L value, an FDRA field and / or FDRA information having a size smaller than the FDRA size based on the K value may be configured and / or indicated. If the RBG size defined and / or set by the existing DCI-based scheduling is K=1, L, which is the RBG size in the case of MC-DCI-based scheduling, is set to a value greater than 1, so that a continuous RBG allocation method based on RIV is applied. The above method may be applied in the case of scheduling multiple cells via MC-DCI. That is, in the case of scheduling only one cell through MC-DCI, K, which is the RBG size defined and / or set in the existing DCI-based scheduling, may be applied.

[0206] In addition, whether to apply the FDRA bit information configuration method based on Option-1 or the FDRA field bit information configuration method based on Option-3 may be indicated by a specific indicator within the MC-DCI. Here, the specific indicator may consist of 1 bit.

[0207] Meanwhile, for the RA type indicator indicating whether the RIV-based contiguous RB (G) allocation method or the RB (G) unit bitmap-based allocation method is applied, the following bit information configuration may be considered to be included in the MC-DCI. The RA type indicator may consist of 1 bit.

[0208] -Configuration A: When only one field indicating the RA type is configured for cells scheduled by the same MC-DCI, the RA type indicated by the field may be commonly applied to all cells, i.e., cells in which the RA type indicator is set in the existing DCI (e.g., DCI scheduled by a single cell) (hereinafter referred to as "configured cells"). In this case, the default RA type may always be applied to cells in which the RA type indicator is not set in the existing DCI-based scheduling (hereinafter referred to as "unconfigured cells"). Here, the cells scheduled by MC-DCI may include a co-scheduled cell set or cells of each cell subgroup belonging thereto. In addition, the configured cell means a cell in which the RA type indicator is set through the existing DCI-based scheduling among the cells belonging to the co-scheduled cell set or each cell subgroup belonging to the cell set. For example, the default RA type may be defined by a RIV-based continuous RB (G) allocation method.

[0209] According to one embodiment, when both configured cells and unconfigured cells are included in a co-scheduled cell set or the same cell subgroup, the field for the RA type indicator may be omitted in the MC-DCI and a default RA type may always be applied.

[0210] According to one embodiment, when both the configured cell and the unconfigured cell are included in a co-scheduled cell set or the same cell subgroup, a field of an RA type indicator may be included in the MC-DCI. At this time, the field indicates the RA type applicable only to the configured cell, and PDSCH / PUSCH transmission and reception may be performed in consideration and / or under the assumption that there is no scheduling for the unconfigured cell. For example, the RA type applicable only to the configured cell may be a bitmap-based RB(G) allocation method.

[0211] According to one embodiment, configured cells and unconfigured cells may be restricted to be included in the same cell subgroup. For example, a cell subgroup may be restricted to only contain configured cells or unconfigured cells.

[0212] -Configuration B:When only one RA type indicator field is configured for cells scheduled by the same MC-DCI, the RA type indicated by the field is applied only to the specified reference cell, and the default RA type set and / or defined in advance may be applied to the remaining cells. Here, the cells scheduled by the same MC-DCI may include a set of cells scheduled together or cells belonging to each cell subgroup of the cell set. In addition, the reference cell may be a cell with the highest or lowest cell index among the cells for which the RA type indicator is set by the existing DCI-based scheduling, a cell with the maximum or minimum SCS, a cell sending MC-DCI, a cell indicated by the CIF field, or a cell directly specified by the RRC. Here, a default RA type may be set and / or defined to indicate a RIV-based continuous RB (G) allocation method.

[0213] -Configuration C : The RA type indicator field may be included in the DCI only when one cell is scheduled by MC-DCI. That is, when multiple cells are scheduled by MC-DCI, the field of the RA type indicator may be omitted in the DCI. When the field of the RA type indicator is included, the RA type indicated by the field may be applied to the cell. On the other hand, when the field of the RA type indicator is not included, a preset and / or defined default RA type may be applied to multiple cells. For example, the default RA type may be set to indicate a RIV-based contiguous RB(G) allocation method.

[0214] -Configuration D : The field for the RA type indicator is not included in the MC-DCI and may be omitted. In this case, a preset and / or defined default RA type may be applied to cells scheduled via MC-DCI. For example, the default RA type may be set to indicate a RIV-based contiguous RB (G) allocation scheme.

[0215] Option 4: Various other indication and scheduling configurations

[0216] As described above, the FDRA field information occupies the largest number of bits among the various information included in the PDCCH (e.g., MIMO (Multiple Input Multiple Output), MCS (Modulation and Coding Scheme), HARQ (Hybrid Automatic Repeat Request), TDRA (Time Domain Resource Allocation), etc.). The above-mentioned options 1, 2, and 3 can be applied to situations where multiple CCs have frequency correlation and shareable characteristics. However, there may be situations where there is no frequency correlation between multiple CCs. In this case, there may be a situation where the FDRA of approximately 14 to 18 bits must be increased by a multiple of the number of multiple CCs. At this time, if a considerable number of cells or carriers are activated at the same time, it is difficult to increase the FDRA by a multiple of the number of CCs. However, if only a small number of CCs are activated, a method of increasing the FDRA by a multiple of the number of CCs can be applied.

[0217] For example, if the number of activated cells is less than N (e.g., 2 or 3), a field in which the FDRA bits are concatenated in a conventional manner may be included in one PDCCH for each cell. However, in the case of the parallel concatenation method, the number of CCs that can be scheduled by MC-DCI may be significantly limited. Therefore, a method of adding all RBs (Gs) of the BWP of all CCs and then roughly controlling the RB (G) size and allocating resources according to the number of RBs (Gs) added (i.e., the total length) may be applied. That is, a new RBG size table may be used that defines RB (G) size values ​​that increase in proportion to the total number of RBs.

[0218] [Table 8] shows an example of an RBG size table when the RBG sizes of all cells are equal.

[0219] [Table 8]

[0220]

[0221] According to one embodiment, the RBG size may be set differently according to the number of RBs or the bandwidth of multiple CCs, and the total number of RBs may be calculated by considering the number of different RBs for each RBG according to the differently set RBG sizes. For example, as shown in [Table 9], the RBG size of CC1 may be set to 5, and the RBG size of CC2 may be set to 3, and then added. That is, the RBG size may be considered before adding the RBs of each CC. In other words, the bandwidth may be considered before adding the RBs of each CC to calculate the total RBG. [Table 9] shows an example of an RBG size table when the RBG sizes of all cells are different.

[0222] [Table 9]

[0223]

[0224] However, when the number of CCs exceeds a certain level, the application of the above method may not be easy. Therefore, the FDRA related information of each carrier or each cell can be transmitted semi-statically in the MAC CE, and the incremental value indicating the difference can be sent using the DCI of the PDCCH. The method of using the MAC CE is as follows.

[0225] 4-1. MAC CE can be used to indicate FDRA information per cell. In this case, the FDRA field of MC-DCI can be omitted. In addition, in some cases, it can be applied to other DCI fields besides FDRA.

[0226] 4-2. Similar to Option 3, the group ID may be added to the information of the reference CC in the MAC CE. At this time, an incremental value indicating the difference from the reference CC may be transmitted using MC-DCI.

[0227] 4-3. A specific flag bit is added to the DCI, and the flag bit indicates one of two options among the predefined options-1, option-2, and option-3, so that the option used between the two options can be changed in real time using the DCI. Therefore, information applicable to option-1, option-2, and option-3 can be added to the DCI in real time.

[0228] 4-4. The maximum size of the FDRA field that can be used in the entire MC-DCI, that is, the number of bits, can be determined in advance. The maximum number of bits of the FDRA field can be preset in a higher layer and can also be determined as a specific value by the standard. In addition, whether the FDRA information of several units within the maximum number of bits of the FDRA field is connected in parallel can be determined in various ways.

[0229] For example, if the maximum number of bits of the FDRA field is 50, the FDRA information of one cell is at most 18 bits based on the maximum BWP of FR1, so it is impossible to connect and send the FDRA information of three cells in parallel through MC-DCI. However, if the size of the BWP is small and the FDRA information of each cell is 10 bits, it is possible to connect the FDRA information of five cells in parallel and send them through MC-DCI. The FDRA information can be used for one cell or for a cell group. In the present disclosure, the FDRA information sent through MC-DCI may include multiple fields. In this case, because the maximum number of bits of the FDRA field in MC-DCI is limited, the number of FDRA fields may vary depending on the BWP. That is, the number of FDRA fields sent through MC-DCI is flexible depending on the size of the BWP. This is because the number of bits of the FDRA information is not fixed like other DCI fields, but varies depending on the BWP. That is, if the maximum number of bits of the FDRA field that can be used in the entire MC-DCI is determined in advance, there may be an advantage that the number of FDRA fields varies within the specified maximum number of bits. This method can be applied not only to the FDRA field, but also to other fields. For example, if multiple values ​​of a specific field need to be sent in MC-DCI as the number of cells increases, the maximum number of bits of the corresponding field can be preset, and the number of fields can be flexibly adjusted within the preset maximum number of bits depending on the situation. According to one embodiment, if the number of FDRA fields to be sent exceeds the maximum number of bits, at least some of the fields exceeding the maximum number of bits can be discarded.

[0230] 4-5. The RA type may be omitted from the DCI and preset in a higher layer. For example, if a 1-bit RA type field is configured for each CC group, the default RA type not indicated by the RA type field may be regarded as only a CC of the default RA type may exist in the unscheduled CC group. The validity of the cell may be distinguished by the 1-bit RA type field. That is, a cell designated as an RA type other than the RA type preset in the cell group or the CC to be scheduled may be regarded as unscheduled.

[0231] In addition, for multiple cells scheduled by the same MC-DCI, the RB (G) index set for each cell can be cascaded in sequence according to the cell index order. That is, a complete RB (G) index set corresponding to the total number of RB (G) set for multiple cells scheduled by the same MC-DCI can be configured. A complete RB (G) index set can be set for each RA type of multiple cells. The RB (G) for each cell can be indicated and / or allocated through an FDRA field based on the entire RB (G) or the entire RB (G) index set. In the RIV-based continuous RB (G) allocation method, a combination of the starting RB (G) index, the ending RB (G) index, or the number of allocated RB (G) can be indicated for each cell, that is, as many as the number of cells.

[0232] In addition, the meaning of sequentially cascading according to the cell index order can be extended as follows. That is, among the CCs in the CC combination that can be co-scheduled in RRC, only the CC activated by the MAC CE can be scheduled using MC-DCI, and at this time, information indicating the validity of the corresponding cell can also be included in the DCI.

[0233] Option 5: Multiple Scheduling Operations of MC-DCI

[0234] As described in Option 1 and Option 2, the reference cell or reference CC means a cell that serves as a scheduling reference among the cells in the group. The resource allocation information of the remaining cells can be interpreted or expressed based on the FDRA information or other DCI field information of the reference cell in the group. The reference cell can be fixedly configured by RRC and can be variable depending on the scheduled CC. If the reference cell is predetermined in a higher layer, the cell preconfigured in the higher layer can be used as a reference cell regardless of the scheduled CC. However, if the reference cell is determined based on the cell index or the number of RB (G), resource allocation can be performed variably depending on the situation. For example, if PCell is included in the scheduled CC, PCell can be designated as the reference cell, and resource allocation can be performed based on PCell.

[0235] There may be a case where the reference CC is not included in the scheduled CC. Therefore, a rule may be set in advance so that the reference CC is always included in the scheduled CC. In addition, a rule may be defined so that only one cell is included in each group, or so that all scheduled CCs are grouped into one group. If a cell configured in a higher layer is determined as a reference cell, the RA efficiency is reduced, but the complexity for generating a retransmission TBS (transport block size) and the complexity of the UE can be reduced. On the other hand, if the reference cell is determined based on the scheduled CC, the RA efficiency is increased, but the complexity for generating a retransmission TBS and the complexity of the UE can increase.

[0236] 5-1: The reference cell may be designated as a cell pre-configured in RRC.

[0237] - The reference cell may indicate a group CC in the MC-DCI, or may indicate all scheduled CCs. This method may be applied to the aforementioned Option-1, Option-2, and Option-3.

[0238] - The reference cell may be designated as one cell indicated by a specific DCI field among a set of values ​​preset in RRC based on FDRA.

[0239] - In addition to the reference cell, multiple cells in the scheduled CC can be grouped into multiple groups, and the reference cell group can be specified among the groups. The cells in the group can share not only FDRA but also all shared common fields. Other cell groups except the reference cell group can be operated using the increment or individual DCI fields of the corresponding cells.

[0240] 5-2: The reference cell may be designated as the cell having the lowest or highest cell ID among the scheduled cells. Alternatively, if multiple CC groups are formed from the scheduled cells, one reference cell may be designated for each group.

[0241] 5-3: When scheduling using the actual MC-DCI, the cell set in the RRC to schedule using one MC-DCI may be in an inactive state. Therefore, in the case of multi-carrier scheduling, the cell can be controlled to be activated simultaneously with the RRC configuration. In addition, the base station can operate the activation / deactivation of the uplink MAC CE SCell and the activation / deactivation of the downlink MAC CE SCell separately depending on the situation.

[0242] 5-4: Which scheduled CC combination is scheduled in the corresponding MC-DCI can be distinguished by a dedicated RNTI for MC-DCI. The base station can group the scheduled CCs, assign different RNTIs (e.g., MC-RNTI1, MC-RNTI2, MC-RNTIx, etc.) to each group, and use different RNTIs to signal them. In this case, various MC-DCIs can be scheduled. The terminal will have to check all RNTIs of the corresponding MC-DCI. In this case, the reference CC for each group or for all scheduled CCs can be determined in advance in a higher layer.

[0243] 5-5: Depending on the type of RNTI, the value of the field applied to MC-DCI may be set differently. For example, the value of the field applied to MC-DCI, such as FDRA, MIMO, TDRA, MCS, or PUCCH transmission, may be set differently. If a table of values ​​of DCI fields whose indexes are applicable is defined and the indexes are mapped to MC-DCI, it may be indicated which value the field uses.

[0244] 5-6: Multiple RNTIs corresponding to MC-DCI may be set in RRC. For example, in the case of scheduling only one cell, C-RNTI may be set, and in the case of scheduling two or more cells, at least one MC-RNTI may be set. According to one embodiment, a different MC-RNTI may be set for each cell. In this case, the number of MC-RNTIs may be determined according to the number of CCs scheduled using MC-DCI.

[0245] When a single cell is scheduled using MC-DCI, C-RNTI may be used. At this time, the CIF indicating the scheduled single cell may be used to indicate the validity of the cell. At this time, according to another embodiment, when a single cell is scheduled using MC-DCI, MC-RNTI may be used instead of C-RNTI.

[0246] MC-DCI scrambled with MC-RNTI may be used to indicate which cell is the reference cell. In this case, MC-RNTI may be selected differently depending on the cell designated as the reference cell. The remaining scheduled CCs other than the reference cell may be identified based on the state of the CIF bit.

[0247] In MC-DCI, CIF may be interpreted differently for single cell and multi-cell.

[0248] When scheduling cells or cell groups of MC-DCI using MC-RNTI scheduling, multiple MC-RNTIs may be allocated, and all cells using MC-DCI scheduled by each MC-RNTI may follow option 1. That is, FDRA is applied as shared-common. For example, in a carrier aggregation scenario including three cells in FR1 and three cells in FR2, a base station may schedule three cells in FR1 using one MC-DCI, and simultaneously schedule three cells in FR2 using another MC-DCI. In this case, different MC-RNTIs may be used to process the two MC-DCIs. The terminal may use fields such as CFI to verify the validity of each cell or cell group. In one embodiment, which cells are mapped to the CC for scheduling of MC-RNTI may be configured in a higher layer. Some cells may be mapped to two MC-DCIs. That is, the cells mapped to MC-DCI may include only cells that may share a common shared DCI field, and may be assigned a specific MC-RNTI suitable for the corresponding MC-DCI.

[0249] 5-7: As an example of RNTI for MC-DCI, it is possible to perform multi-cell scheduling using CS (Configured Scheduling)-RNTI that can be triggered once. In this case, it is preferable to pre-configure the CS of the cell scheduled by RRC.

[0250] When cells scheduled using DCI (eg, dynamically scheduled cells) and unscheduled cells (eg, cells scheduled according to CS or configured grant (CG)) are included in a co-scheduled CC, the validity of the cells may be determined according to the RNTI.

[0251] i. When an RNTI called MC-CS-RNTI is defined and DCI for CS is transmitted using MC-CS-RNTI, only CCs configured with CS can be considered valid. If DCI is processed using MC-RNTI, only CCs not applied with CS can be considered valid.

[0252] ii. CCs scheduled using one MC-DCI may include only cells configured with CS or only cells not configured.

[0253] 5-8: For each cell, at least one remaining field exists except for fields such as FDRA, TDRA, MCS, RA type, and PUCCH-related configuration that may be shared. The field that exists for each cell may be referred to as a "separate field". In the separate field, the value of the reference CC may be placed in front. Depending on the field, the value of the reference CC may be omitted. For example, when indicating the validity for each CC, validity mapping may be performed on the CIF bits of the remaining cells except the reference CC (for example, if it consists of 3 bits, 0 means no scheduling), and the mapping order (for example, ascending or descending) may be determined according to the cell ID.

[0254] In case of separate fields, each bit of one CIF can indicate the validity of a cell group and a single cell.

[0255] 5-9: When only MC-RNTI is used in MC-DCI, MC-RNTI can be used to indicate which CC in the CC is the reference CC. Specifically, it can be checked which CC is the reference CC depending on whether MC-DCI is scheduled for the corresponding cell. For example, the reference CC can be specified in RRC. In this case, the MC-DCI that schedules a specific CC combination can be mapped to one RNTI. And, the configuration reconfigured in RRC for the reference CC can become the basis for interpreting the DCI fields of other cells.

[0256] According to one embodiment, if a cell scheduled using MC-DCI (e.g., a cell that transmits MC-DCI) is not included in a scheduled CC (e.g., a cell corresponding to resources allocated by MC-DCI), cell-related information preset in RRC (e.g., FDRA, MCS, or PUCCH-related information) may be used. Alternatively, if a cell scheduled using MC-DCI is not included in a scheduled CC, cell-related information based on the scheduled cell (e.g., FDRA, MCS, or PUCCH-related information) may be used, and the cell scheduled using MC-DCI may not be considered a scheduled cell.

[0257] The cell that sends the MC-DCI scrambled with the MC-RNTI may be a specific cell or a designated cell among the scheduled cells. The cell may be preconfigured in a higher layer. At this time, the cell that schedules the MC-DCI may not send the legacy DCI provided for the C-RNTI usage of the existing conventional USS (User Specific Search Space).

[0258] Scheduling MC-DCI for a single cell may be limited to only the cell that transmits the MC-DCI. That is, cross-carrier scheduling is not used, and only self-scheduling is possible.

[0259] 5-10: FDRA can be used to indicate which scheduled CC is actually scheduled (for example, whether it is valid). At this time, the order of the indicated cells can be determined by the cell index. In this case, the value of the actually scheduled cell or cell group can be set to the FDRA information, and the value of the unscheduled cell or cell group can be set to a specified 1-bit value (for example, "0"). When FDRA is set for each cell group, the FDRA field can follow the shared-common method as described in Option-1.

[0260] 5-11: CIF may indicate the number of currently scheduled CCs, and the number of scheduled CCs may be up to 8. At this time, all scheduled CCs follow the shared-common method, and the order of scheduled CCs may be mapped in the order of low or high cell indexes.

[0261] 5-12: Among the 3-bit CIF, one bit can indicate the reference CC, the FDRA of the current MC-DCI, or another DCI field available in a shared-common manner, and the remaining two bits can indicate the number of scheduled CCs or the number of groups. At this time, up to 2 FDRA fields can be transmitted.

[0262] 5-13: The number of groups that can be scheduled using MC-DCI is set to 1, 2, or 3, and each group may include multiple cells. It is possible to check which cells in the group are valid or invalid based on whether the value indicated by the reference cell is the same as the value predetermined by the higher layer, for example, using the RA field or the VRB to PRB mapping bit. That is, if the value indicated by the reference cell is the same as the value predetermined by the higher layer, the cell is a valid cell for scheduling, and if not, the cell can be considered as an unscheduled invalid cell. Here, there may be only one cell in a cell group, or there may be only one cell group.

[0263] 5-14: When a reference cell is specified in a cell group or a scheduled CC, the FDRA information may be located at the front of the field, and the validity of the reference cell may be indicated in the first bit of the CIF. In other words, the FDRA information of the reference CC may be located at the front of the FDRA field, and the validity of the reference CC may be located at the front of the CIF.

[0264] 5-15: MC-RNTI may be set differently depending on the number of cells or cell groups scheduled using MC-DCI. When one cell or cell group is scheduled using MC-DCI, C-RNTI may be used.

[0265] 5-16: Some DCI fields among the DCI fields can be used in a common-shared manner in multiple cells, but some DCI fields must be used individually among multiple cells. The individual use and common use of each DCI field can be preset in a higher layer. When used individually, the maximum total number of available bits for each field is determined, and if the total number is exceeded, the cell can be considered invalid in scheduling.

[0266] According to an embodiment of the present disclosure, through the above method, the convenience of scheduling can be improved by clearly indicating which cell or which cell group the scheduling is for.

[0267] As carrier aggregation evolves and develops to 5G NR, the frequency band that can be transmitted simultaneously has increased to 6GHz or higher, 20GHz, 30GHz, 60GHz or 100GHz millimeter waves, and therefore, the number of cells operating simultaneously has been rapidly increased. Since the previous 4G LTE, whether the self-scheduling method or the cross-carrier scheduling method is used, PDCCH, that is, DCI, has to be sent once in order to send one PDSCH in one cell. When the number of PDSCHs that have to be sent simultaneously is small, the terminal does not bring a great burden by decoding PDCCH multiple times. However, when the number of PDSCHs that have to be sent simultaneously is large and the terminal has to decode a large number of PDCCHs, it will affect the performance of the terminal and occupy a large amount of frequency and time resource unit areas, which may also have a negative impact on the availability of resource elements for service transmission. Therefore, a method of scheduling PDSCHs of multiple cells using one PDCCH may be effective. However, because the maximum amount of bit information that can be used as a payload in 5G NR is limited, and the FDRA information for each cell requires a large number of bits, it is difficult to use multiples of the number of CCs for the bits of FDRA information in one PDCCH.

[0268] Therefore, the present disclosure proposes a method capable of scheduling multiple cells without using many bits in PDCCH. That is, according to an embodiment of the present disclosure, scheduling for multiple carriers in one PDCCH is possible, and an option suitable for the number of CCs can be adaptively selected and operated depending on the situation.

[0269] As described above, multi-carrier scheduling may be performed according to various embodiments. MC-DCI may be used for multi-carrier scheduling, and MC-DCI includes at least one field including frequency resource allocation information for multiple CCs, i.e., FDRA values. Hereinafter, the operations of a base station and a terminal performing multi-carrier scheduling according to the above-described embodiments will be described with reference to the accompanying drawings.

[0270] Fig.13 An example of a frequency domain resource information acquisition process in a wireless communication system according to an embodiment of the present disclosure is illustrated. Fig.13 The diagram illustrates the operation method of the base station.

[0271] refer to Fig.13 In step S1301, the base station performs a connection establishment process for the primary cell. After the terminal accesses the base station, the base station performs a connection establishment process with the terminal. To this end, the base station may receive a connection establishment request message from the terminal and send a connection establishment completion message. Fig.13 Not shown in the figure, before step S1301, the base station may perform an initial access procedure by receiving a random access preamble from the terminal and sending a random access response (RAR) message.

[0272] In step S1303, the base station performs a connection establishment process for at least one secondary cell. After establishing a connection to the primary cell of the terminal, the base station performs an additional connection establishment process with the terminal. To this end, the base station may receive a reconfiguration message for the connection from the terminal and send a reconfiguration completion message. Therefore, a primary cell and at least one secondary cell may be configured between the base station and the terminal. In addition, although Fig.13 Although not shown in the figure, the base station may send a MAC CE for activating at least one secondary cell.

[0273] In step S1305, the base station sends DCI. Here, the DCI may include information for multi-carrier scheduling. That is, the base station allocates resources of multiple cells to the terminal, generates DCI indicating the allocated resources, and sends the DCI to the terminal through one of the multiple cells. For example, the DCI may include information indicating resources allocated in multiple cells including a primary cell and at least one secondary cell. At this time, the frequency resources used for each cell may be indicated according to the various embodiments described above. In some cases, resources may not be allocated in some of the multiple cells. In this case, the DCI may include information indicating that no resources are allocated to it, that is, at least one cell that is not actually scheduled.

[0274] In step S1307, the base station sends or receives data on multiple cells. The base station can send or receive data through the resources of multiple cells indicated by the DCI. If the downlink resources are allocated by the DCI, the base station sends the data. To this end, the base station can perform channel coding, scrambling, rate matching, constellation mapping, resource mapping, layer mapping, waveform modulation, etc. If the uplink resources are allocated by the DCI, the base station receives the data. To this end, the base station can perform waveform demodulation, constellation demapping, channel decoding, etc.

[0275] Fig.14 An example of a frequency domain resource information transmission process in a wireless communication system according to an embodiment of the present disclosure is illustrated. Fig.14 Illustrated terminal operation method.

[0276] refer to Fig.14 In step S1401, the terminal performs a connection establishment process for the primary cell. After the terminal accesses the base station, the terminal performs a connection establishment process with the base station. To this end, the terminal can send a connection request message to the base station and receive a setup completion message. Fig.14 Although not shown in the figure, before step S1401, the terminal may perform an initial access procedure by sending a random access preamble to the base station and receiving a random access response message.

[0277] In step S1403, the terminal performs a connection establishment process for at least one secondary cell. After the connection to the primary cell of the terminal is established, the terminal performs an additional connection establishment process with the base station. To this end, the terminal may send a reconfiguration message for the connection to the base station and receive a reconfiguration completion message. Therefore, a primary cell and at least one secondary cell may be configured between the base station and the terminal. In addition, although Fig.14 Although not shown in the figure, the terminal may receive a MAC CE for activating at least one secondary cell.

[0278] In step S1405, the terminal receives DCI. Here, the DCI may include information for multi-carrier scheduling. That is, the terminal may check the result of multi-carrier scheduling through the DCI. For example, the DCI may include information indicating resources allocated in multiple cells including a primary cell and at least one secondary cell. At this time, the frequency resources used for each cell may be indicated according to the various embodiments described above. In some cases, resources may not be allocated in some of the multiple cells. In this case, the DCI may include information indicating that no resources are allocated to it, that is, at least one cell is not actually scheduled.

[0279] In step S1407, the terminal receives or sends data on multiple cells. The terminal can receive or send data through the resources of multiple cells indicated by the DCI. If the downlink resources are allocated by the DCI, the terminal receives the data. To this end, the terminal can perform waveform demodulation, constellation demapping, channel decoding, etc. If the uplink resources are allocated by the DCI, the terminal sends the data. To this end, the terminal can perform channel coding, scrambling, rate matching, constellation mapping, resource mapping, layer mapping, waveform modulation, etc.

[0280] Fig.15 An example of a process for indicating whether to perform scheduling on each cell using FDRA information in a wireless communication system according to an embodiment of the present disclosure is illustrated. Fig.15 The diagram shows signal exchange between terminal 1510 and base station 1520. Fig.15 In the embodiment, the base station 1520 is described as providing two cells 1522-1 and 1522-2, but the process described below may also be applied to the case of providing three or more cells.

[0281] refer to Fig.15 In step S1501, the base station 1520 allocates resources of the first cell 1522-1 to the terminal 1510, and does not allocate resources of the second cell 1522-2. Here, the first cell 1522-1 and the second cell 1522-2 are CCs provided to the terminal 1510 through carrier aggregation, and one of the first cell 1522-1 and the second cell 1522-2 is a primary cell and the other is a secondary cell.

[0282] In step S1503, the base station 1520 sends a DCI to the terminal 1510. That is, the base station 1520 sends information related to the resources allocated in step S1501. At this time, the DCI includes information indicating that the resources of the second cell 1522-2 are not allocated, that is, no actual scheduling is performed in the second cell 1522-2. According to one embodiment, the DCI includes FDRA information for the second cell 1522-2, and the FDRA information for the second cell 1522-2 may be set to all 0s. That is, the bits indicating the FDRA information for the second cell 1522-2 may be set to all 0s. Here, all 0s are an example of a value that is not used when allocating resources, and in other embodiments, a value other than all 0s may be used to indicate that resources are not allocated.

[0283] In step S1505, the terminal 1510 identifies that the resources of the second cell 1522-2 are not allocated. That is, the terminal 1510 receives the DCI and identifies the information in the DCI indicating that the actual scheduling is not performed in the second cell 1522-2 (for example, the FDRA information is set to all 0s), thereby checking that the actual scheduling is not performed in the second cell 1522-2. Then, the terminal 1510 identifies the resources allocated in the first cell 1522-1 through the DCI.

[0284] In step S1507, base station 1520 transmits data to terminal 1510 through resources of first cell 1522-1. In other words, base station 1520 transmits a signal including data to terminal 1510 through PDSCH of first cell 1522-1. Here, PDSCH is mapped to resources indicated by DCI transmitted in step S1503.

[0285] Fig.16 An example of a process for performing multi-carrier scheduling according to a shared-common method in a wireless communication system according to an embodiment of the present disclosure is illustrated. Fig.16 The diagram shows signal exchange between terminal 1610 and base station 1620.

[0286] refer to Fig.16 In step S1601, the base station 1620 performs scheduling. The base station 1620 provides the first cell 1622-1 to the Nth cell 1622-N to the terminal 1610 using carrier aggregation, and performs scheduling to perform communication using resources of the first cell 1622-1 to the Nth cell 1622-N. Therefore, resources of each of the first cell 1622-1 to the Nth cell 1622-N can be allocated to the terminal 1610.

[0287] In step S1603, the base station 1620 generates a common FDRA value for all cells. The common FDRA value indicates the allocation result of frequency resources for all cells to be scheduled by using one value. To this end, the base station 1620 can determine a group of cells to be scheduled together using one PDCCH, and select a reference cell among the cells belonging to the group. In this embodiment, the first cell 1622-1 to the Nth cell 1622-N are grouped into a group. For example, the reference cell can be selected based on at least one of the number of RBs (G) set in the cell and the cell index. Then, the base station 1620 can generate an FDRA value indicating the scheduling result based on the RBs (G) of the reference cell.

[0288] In step S1605, the base station 1620 sends DCI through the resources of the first cell 1622-1. In other words, the base station 1620 sends DCI through the PDCCH of the first cell 1622-1. Here, the DCI includes the FDRA value generated in step S1603. That is, the DCI may include an FDRA value indicating the scheduling result of the RB (G) based on the reference cell. Alternatively, when multiple groups are formed, the DCI may further include identification information of the group. If at least one cell among the cells 1622-1 to 1622-N included in the group is not actually scheduled, the DCI may further include information indicating at least one cell that is not actually scheduled, i.e., invalid. In addition, the DCI may further include information indicating the reference cell.

[0289] In step S1607, the base station 1620 uses the resources of the first cell 1622-1 to the Nth cell 1622-N to transmit data. The terminal 1610 can check the resources allocated from the first cell 1622-1 to the Nth cell 1622-N based on the FDRA value included in the DCI. At this time, because the FDRA value is determined based on the RB (G) of the reference cell, the terminal 1610 can check the resources allocated from the reference cell explicitly indicated by the FDRA value, and can check the resources allocated from at least one other cell other than the reference cell by interpreting the FDRA value according to the established rules. Here, the rule for interpreting the FDRA value can be set in advance by separate signaling (e.g., higher layer signaling of the physical layer).

[0290] As reference Fig.16 As described above, resources allocated from multiple cells are indicated using a common FDRA value. Therefore, during the scheduling step, i.e., the scheduling operation in step S1601, resources of other cells can be allocated by considering the RB (G) structure of the reference cell. That is, resources of each cell can be allocated within the range indicated using the common FDRA value.

[0291] Fig.17An example of a process for performing multi-carrier scheduling according to a separate-incremental method in a wireless communication system according to an embodiment of the present disclosure is illustrated.

[0292] refer to Fig.17 In step S1701, the base station 1720 performs scheduling. The base station 1720 provides the first cell 1722-1 to the Nth cell 1722-N to the terminal 1710 using carrier aggregation, and performs scheduling to perform communication using resources of the first cell 1722-1 to the Nth cell 1722-N. Therefore, resources of each of the first cell 1722-1 to the Nth cell 1722-N can be allocated to the terminal 1710.

[0293] In step S1703, the base station 1720 generates an FDRA value for the reference cell. To this end, the base station 1720 may determine a group of cells co-scheduled using one PDCCH and select a reference cell among the cells belonging to the group. In this embodiment, the first cell 1722-1 to the Nth cell 1722-N are grouped into one group. For example, the reference cell may be selected based on at least one of the number of RBs (G) set in the cell and the cell index. Then, the base station 1720 may generate an FDRA value indicating the resources allocated in the reference cell.

[0294] In step S1705, the base station 1720 generates an incremental value for at least one remaining cell. That is, the base station 1720 generates information that can indicate resources allocated in another cell by combining with the FDRA value of the reference cell generated in step S1703. An incremental value is generated for each cell except the reference cell, and can indicate resources to be added or excluded compared to the reference cell.

[0295] In step S1707, the base station 1720 sends DCI through the resources of the first cell 1722-1. In other words, the base station 1720 sends DCI through the PDCCH of the first cell 1722-1. Here, the DCI includes the FDRA value generated in step S1703 and at least one incremental value generated in step S1705. Alternatively, if multiple groups are formed, the DCI may further include identification information of the group. If at least one cell among the cells 1722-1 to 1722-N included in the group is not actually scheduled, the DCI may further include information indicating at least one cell that is not actually scheduled, i.e., invalid. In addition, the DCI may further include information indicating a reference cell.

[0296] In step S1709, the base station 1720 uses resources of the first cell 1722-1 to the Nth cell 1722-N to send data. The terminal 1710 can check the resources allocated in the first cell 1722-1 to the Nth cell 1722-N based on at least one incremental value and the FDRA value included in the DCI. At this time, because the incremental value is determined based on the FDRA value of the reference cell, the terminal 1710 can check the resources allocated in the reference cell indicated by the FDRA value, and check the resources allocated in at least one other cell other than the reference cell based on the incremental value. Here, the rules for interpreting the FDRA value and the incremental value can be set in advance through separate signaling (e.g., higher layer signaling of the physical layer).

[0297] Fig.18 An example of a process for performing multi-carrier scheduling according to a separate-equal method in a wireless communication system according to an embodiment of the present disclosure is illustrated.

[0298] refer to Fig.18 In step S1801, the base station 1820 performs scheduling. The base station 1820 provides the first cell 1822-1 to the Nth cell 1822-N to the terminal 1810 using carrier aggregation, and performs scheduling to perform communication using resources of the first cell 1822-1 to the Nth cell 1822-N. Therefore, the resources of each of the first cell 1822-1 to the Nth cell 1822-N can be allocated to the terminal 1810.

[0299] In step S1803, the base station 1820 distributes the bits of the FDRA field to multiple cells 1822-1 to 1822-N. To this end, the base station 1820 can determine a group of cells that are co-scheduled using one PDCCH. In this embodiment, the first cell 1822-1 to the Nth cell 1822-N are grouped into a group. The base station 1820 can distribute the bits evenly to the cells. Alternatively, the base station 1820 can distribute the bits unevenly to the cells according to a predefined or set rule. For example, the base station 1820 can distribute the bits based on at least one of the BWP size, the number of RB(G), and the RB(G) size of each cell.

[0300] In step S1805, the base station 1820 generates a FDRA value for each of the plurality of cells 1822-1 to 1822-N. The FDRA value for each cell can be determined within a range expressible by bits allocated to the corresponding cell. That is, one FDRA field can include a plurality of FDRA values.

[0301] In step S1807, the base station 1820 sends DCI through the resources of the first cell 1822-1. In other words, the base station 1820 sends DCI through the PDCCH of the first cell 1822-1. Here, the DCI includes the FDRA value generated in step S1805. Alternatively, if multiple groups are formed, the DCI may further include identification information of the group. If at least one cell among the cells 1822-1 to 1822-N included in the group is not actually scheduled, the DCI may further include information indicating at least one cell that is not actually scheduled, i.e., invalid. In addition, the DCI may further include information indicating the RA type.

[0302] In step S1809, the base station 1820 transmits data using resources of the first cell 1822-1 to the Nth cell 1822-N. The terminal 1810 may check the resources allocated in the first cell 1822-1 to the Nth cell 1822-N based on the FDRA value included in the DCI. At this time, the FDRA value may be interpreted based on the RA type. Therefore, the terminal 1810 may check the RA type applied to each of the plurality of cells 1822-1 to 1822-N based on at least one of the DCI or separate signaling, and interpret the FDRA value.

[0303] Multi-carrier scheduling can be performed according to the various processes described above. Fig.16 , Fig.17 and Fig.18 The described processes are examples of processes according to the shared-common method, the separate-incremental method, and the separate-equal method, respectively. However, the above processes may be applied jointly. In addition, the various embodiments described in the above various options (e.g., options 1 to 4) can be combined with the above processes. Therefore, the multi-carrier scheduling according to various embodiments of the present disclosure can be modified in more different ways.

[0304] With the evolution and development of 5G NR, the frequency bands that can be transmitted simultaneously using carrier aggregation have increased to 6GHz or higher or 20GHz, 30GHz, 60GHz and 100GHz of millimeter waves, and the number of cells operating simultaneously has increased significantly. Since the previous 4G system, regardless of whether it is a self-scheduling method or a cross-carrier scheduling method, it has been a rule to send at least one PDCCH, i.e., DCI, for a PDSCH transmission in a cell. If the number of PDSCHs sent at the same time is small, the burden of decoding PDCCH multiple times will not be great. However, if a certain number of PDCCHs must be decoded, it will not only affect the performance of the terminal, but also consume a lot of frequency and time resources. Therefore, the resources used for service transmission may be reduced.

[0305] Therefore, a method of scheduling the PDSCH of multiple cells using a single PDCCH is more desirable. However, due to the limitation of the maximum amount of available information in the 5G NR system, it is difficult to send a FDRA that requires a large number of bits as many as the number of CCs. Therefore, the present disclosure proposes a control method that is capable of scheduling many cells without using a number of bits that increases proportionally with the number of CCs for the FDRA in the PDCCH, i.e., DCI. According to the various embodiments described above, multi-carrier scheduling using a single PDCCH is possible, and from an operational perspective, it will be possible to selectively apply appropriate options according to the number of CCs.

[0306] The example of the above-mentioned proposed method may be included as one of the implementation methods of the present disclosure, and thus may be regarded as a kind of the proposed method. In addition, the above-mentioned proposed method may be implemented independently, or some proposed methods may be combined (or merged). The rule may be defined so that the base station notifies the UE of information on whether to apply the proposed method (or information on the rule of the proposed method) through a predefined signal (e.g., a physical layer signal or a higher layer signal).

[0307] Those skilled in the art will appreciate that the present disclosure can be implemented in other specific ways than those described herein without departing from the spirit and essential characteristics of the present disclosure. Therefore, the above exemplary embodiments should be interpreted in all respects as illustrative and not restrictive. The scope of the present disclosure should be determined by the appended claims and their legal equivalents, rather than by the above description, and it is intended that all changes that come within the meaning and equivalent range of the appended claims are covered therein. In addition, it will be apparent that some claims that refer to specific claims can be combined with another claim that refers to other claims other than the specific claims to constitute an embodiment, or new claims can be added by means of amendments after the application is submitted.

[0308] Industrial Applicability

[0309] Embodiments of the present disclosure are applicable to various radio access systems. Examples of various radio access systems include the 3rd Generation Partnership Project (3GPP) or 3GPP2 system.

[0310] The embodiments of the present disclosure are applicable not only to various radio access systems but also to all technical fields to which various radio access systems are applied. In addition, the proposed method is applicable to millimeter wave and terahertz wave communication systems using ultra-high frequency bands.

[0311] Additionally, embodiments of the present disclosure are applicable to various applications, such as autonomous vehicles, drones, and the like.

Claims

1. A method of operating a user equipment (UE) in a wireless communication system, the method comprising: Execute access process with base station; executing, for a primary cell, a connection establishment process with the base station; performing, for at least one secondary cell, a connection establishment process with the base station; receiving downlink control information (DCI) from the base station; as well as receiving data using resources indicated by the DCI, The DCI includes information indicating resources allocated in a plurality of cells including the primary cell and the at least one secondary cell and information indicating at least one cell that is not actually scheduled among the primary cell and the at least one secondary cell.

2. The method according to claim 1, wherein: The information indicating the at least one cell that is not actually scheduled includes frequency domain resource allocation (FDRA) information set to a value defined as indicating that resources are not allocated.

3. The method according to claim 2, wherein: The value defined to indicate that a resource is not allocated includes a value that is not used when the resource is allocated.

4. The method according to claim 2, wherein: The value defined to indicate that resources are not allocated comprises all zeros.

5. The method according to claim 1, wherein: The DCI indicates the resources based on the number of resource block groups (RBGs) of the plurality of cells.

6. The method according to claim 5, wherein: The number of the RBGs is determined based on an RBG size according to a bandwidth part (BWP) size of each of the plurality of cells.

7. The method according to claim 1, wherein: The DCI includes an FDRA value commonly applied to the plurality of cells, the FDRA value being generated based on a resource structure of a reference cell among the plurality of cells.

8. The method according to claim 1, wherein: The DCI includes an FDRA value generated from a resource structure of a reference cell among the plurality of cells and commonly applied to the plurality of cells.

9. The method according to claim 1, further comprising: receiving information related to a reference cell among the plurality of cells, The information related to the reference cell is received through a medium access control element (MAC) control element (CE), a radio resource control (RRC) message or the DCI.

10. The method according to claim 1, wherein: The DCI includes a reference FDRA value generated based on a resource structure of a reference cell among the plurality of cells and an incremental value compared to the reference FDRA value applied to at least one cell other than the reference cell.

11. The method according to claim 1, wherein: The DCI includes a FDRA value for each of the plurality of cells.

12. A method for operating a base station in a wireless communication system, the method comprising: Perform access procedures with user equipment (UE); Performing a connection establishment process on a primary cell of the UE; Performing a connection establishment process on at least one secondary cell of the UE; Sending downlink control information (DCI) to the UE; as well as sending data using the resources indicated by the DCI, The DCI includes information indicating resources allocated in a plurality of cells including the primary cell and the at least one secondary cell and information indicating at least one cell that is not actually scheduled among the primary cell and the at least one secondary cell.

13. The method according to claim 12, wherein: The information indicating the at least one cell that is not actually scheduled includes frequency domain resource allocation (FDRA) information set to a value defined as indicating that resources are not allocated.

14. The method according to claim 13, wherein: The value defined to indicate that a resource is not allocated includes a value that is not used when the resource is allocated.

15. The method according to claim 13, wherein: The value defined to indicate that resources are not allocated comprises all zeros.

16. The method according to claim 12, in, The DCI indicates the resources based on the number of resource block groups (RBGs) of the plurality of cells, and The number of the RBGs is determined based on an RBG size according to a bandwidth part (BWP) size of each of the plurality of cells.

17. A user equipment (UE) in a wireless communication system, the UE comprising: Transceiver; as well as a processor connected to the transceiver, Wherein, the processor is configured to: Execute access process with base station; executing, for a primary cell, a connection establishment process with the base station; performing, for at least one secondary cell, a connection establishment process with the base station; receiving downlink control information (DCI) from the base station; and receiving data using the resources indicated by the DCI, The DCI includes information indicating resources allocated in a plurality of cells including the primary cell and the at least one secondary cell and information indicating at least one cell that is not actually scheduled among the primary cell and the at least one secondary cell.

18. A base station in a wireless communication system, the base station comprising: Transceiver; as well as a processor connected to the transceiver, Wherein, the processor is configured to: Perform access procedures with user equipment (UE); Performing a connection establishment process on a primary cell of the UE; Performing a connection establishment process on at least one secondary cell of the UE; sending downlink control information (DCI) to the UE; and sending data using the resources indicated by the DCI, The DCI includes information indicating resources allocated in a plurality of cells including the primary cell and the at least one secondary cell and information indicating at least one cell that is not actually scheduled among the primary cell and the at least one secondary cell.

19. A communication device, comprising: at least one processor; as well as at least one computer memory connected to the at least one processor to store instructions that direct operations when executed by the at least one processor, The operations include: Execute access process with base station; executing, for a primary cell, a connection establishment process with the base station; performing, for at least one secondary cell, a connection establishment process with the base station; receiving downlink control information (DCI) from the base station; and receiving data using the resources indicated by the DCI, The DCI includes information indicating resources allocated in a plurality of cells including the primary cell and the at least one secondary cell and information indicating at least one cell that is not actually scheduled among the primary cell and the at least one secondary cell.

20. A non-transitory computer-readable medium storing at least one instruction, the non-transitory computer-readable medium comprising the at least one instruction executable by a processor, in, The at least one instruction instructs the device to: Execute access process with base station; executing, for a primary cell, a connection establishment process with the base station; performing, for at least one secondary cell, a connection establishment process with the base station; receiving downlink control information (DCI) from the base station; as well as receiving data using the resources indicated by the DCI, The DCI includes information indicating resources allocated in a plurality of cells including the primary cell and the at least one secondary cell and information indicating at least one cell that is not actually scheduled among the primary cell and the at least one secondary cell.

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