CN116801398A - User equipment and base station communicating with each other and method of operating the same - Google Patents

Abstract

Disclosed are a user equipment and a base station communicating with each other and a method of operating the same. A method of operation of a User Equipment (UE), comprising: receiving a Physical Downlink Control Channel (PDCCH) from a Base Station (BS), wherein the PDCCH corresponds to a cell group comprising a plurality of cells, and wherein the PDCCH is received through a specific cell in the cell group; obtaining Downlink Control Information (DCI) from the PDCCH, identifying whether scheduling has been performed on the cell group based on the DCI, and receiving a Physical Downlink Shared Channel (PDSCH) from the Base Station (BS) based on the DCI, wherein the PDSCH corresponds to the cell group and is received through the plurality of cells.

Description

User equipment and base station communicating with each other and method of operating the same

Cross Reference to Related Applications

The present application is based on and claims priority of korean patent application No. 10-2022-0034941 filed in the korean intellectual property office at 3-21 of 2022 and korean patent application No. 10-2022-007575 filed in 6-21 of 2022, the contents of which are incorporated herein by reference in their entireties.

Technical Field

The present disclosure relates to wireless communication, and in particular, to a User Equipment (UE) and a Base Station (BS) that perform communication with each other based on a specific network, and an operating method thereof.

Background

Due to commercialization of Long Term Evolution (LTE) communication systems and growth of multimedia services, next generation communication systems, such as New Radio (NR) communication systems, have been developed to satisfy increasing use of wireless data services.

Thus, communication in a very high frequency (mmWave) band is proposed for an NR communication system to increase a data rate. In addition, beamforming, massive multiple-input multiple-output, full-dimensional multiple-input multiple-output, array antennas, analog beamforming, and massive antenna techniques are used in NR communication systems to reduce the passing loss of radio waves and increase the propagation distance of radio waves in very high frequency bands.

In some cases, in the next-generation communication system (i.e., NR communication system), communication is performed in a wide range of frequency bands. For example, a frequency band may be divided into multiple frequency bands for efficient use of resources and network flexibility. The BS may communicate with the UE using a plurality of frequency bands, and the BS transmits scheduling information of the frequency bands to the UE through the plurality of frequency bands. The BS may transmit scheduling information of each of the plurality of frequency bands to the UE through efficient and effective resource allocation, and the UE may effectively receive the scheduling information.

Disclosure of Invention

Embodiments of the present disclosure include a Base Station (BS) transmitting scheduling information of each of a plurality of frequency bands to a User Equipment (UE). Thus, less resources are used, which provides for efficient use of resources and network flexibility. Embodiments of the present disclosure include a UE that receives scheduling information transmitted from a BS through reduced resources.

Embodiments of the present disclosure include a serving cell that generates and provides directional information to a UE. In some cases, the UE may identify a region of the region of coreset that matches the narrowband. According to an aspect of the present disclosure, there is provided an operation method of a user equipment, the operation method including: a Physical Downlink Control Channel (PDCCH) is received. In some cases, the physical downlink control channel corresponds to a cell group comprising a plurality of cells and is received from a base station by a particular cell in the cell group. The operation method further comprises the following steps: downlink Control Information (DCI) is acquired from the PDCCH, whether scheduling has been performed on the cell group is identified based on the DCI, and a Physical Downlink Shared Channel (PDSCH) corresponding to the cell group is received from the base station through the plurality of cells based on the DCI.

According to another aspect of the present disclosure, there is provided an operation method of a base station, the operation method including: higher layer signaling for scheduling settings for user equipment and cell groups is performed. In some cases, a user equipment and a cell group generate Downlink Control Information (DCI) including information indicating at least one of a cell group and a plurality of cells included in the cell group based on the higher layer signaling, select one cell from the plurality of cells based on the higher layer signaling, schedule a Physical Downlink Control Channel (PDCCH) including the DCI and corresponding to the cell group based on the selected cell, and transmit the scheduled PDCCH to the user equipment.

There is provided a user equipment comprising: a transceiver configured to receive a Physical Downlink Control Channel (PDCCH). The physical downlink control channel corresponds to a cell group including a plurality of cells and is received from a base station through a specific cell in the cell group. The user equipment further comprises: a controller configured to obtain Downlink Control Information (DCI) from a PDCCH and identify whether scheduling is performed on a cell group based on the DCI. The controller is configured to control the transceiver to receive a Physical Downlink Shared Channel (PDSCH) corresponding to the cell group from the base station through the plurality of cells based on the DCI.

According to another aspect of the present disclosure, there is provided a base station comprising a plurality of transceivers and a controller configured to control the plurality of transceivers to perform higher layer signaling for scheduling settings for user equipment and cell groups. The controller is configured to generate Downlink Control Information (DCI) including information indicating the cell group and at least one of a plurality of cells included in the cell group based on the higher layer signaling, select one of the plurality of cells based on the higher layer signaling, and perform scheduling on a Physical Downlink Control Channel (PDCCH) including the DCI and corresponding to the cell group based on the selected cell.

According to another aspect of the present disclosure, there is provided a User Equipment (UE) configured to: receiving a Physical Downlink Control Channel (PDCCH) from a Base Station (BS) using a first cell of a cell group; obtaining Downlink Control Information (DCI) from the PDCCH, wherein the DCI includes scheduling information for a first cell and a second cell in the cell group; and receiving a Physical Downlink Shared Channel (PDSCH) from the Base Station (BS) based on the DCI using the first cell and the second cell.

Drawings

The embodiments will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings in which:

fig. 1 is a diagram illustrating a wireless communication system according to an embodiment;

fig. 2 and 3 are block diagrams illustrating an implementation of a base station and a user equipment according to an embodiment;

fig. 4A is a diagram showing a structure of a time-frequency domain as a radio resource region in a wireless communication system;

fig. 4B is a diagram showing a slot structure in a wireless communication system;

fig. 4C is a diagram showing an example of implementation of a bandwidth portion in a first frequency band of a wireless communication system;

fig. 4D is a diagram showing an example of coreset in a wireless communication system;

fig. 4E is a diagram showing the structure of coreset in the wireless communication system;

fig. 5 is a flow chart illustrating a method of operating a wireless communication system;

fig. 6A to 6C are diagrams showing a first cell group according to an embodiment;

fig. 6D is a diagram showing a first cell group and a second cell group;

fig. 7A to 9 are diagrams showing scheduling related information for a cell group;

fig. 10A and 10B are flowcharts showing an operation method of a base station for selecting a specific cell;

fig. 11A to 11C are flowcharts showing an operation method for a user equipment for identifying whether scheduling has been performed on a cell group;

Fig. 12A is a diagram showing an operation method of a user equipment for identifying whether scheduling has been performed on a cell group;

fig. 12B is a flowchart illustrating a detailed operation method of the user equipment in operation S420 of fig. 12A;

fig. 13 is a flowchart illustrating an operation method of the user equipment to perform blind decoding;

fig. 14 is a flowchart showing an operation method of a base station to determine a carrier index;

fig. 15 is a flowchart illustrating an operation method of a user equipment to determine the size of a frequency domain resource allocation field; and

fig. 16 is a conceptual diagram illustrating an application in an IoT network system.

Detailed Description

The present disclosure relates to a wireless communication system. Embodiments of the present disclosure include a Base Station (BS) transmitting scheduling information of each of a plurality of frequency bands to a User Equipment (UE). Thus, less resources are used, which provides for efficient use of resources and network flexibility. For example, the UE may receive scheduling information transmitted from the BS through reduced resources. In some cases, a serving cell that generates and provides directional information to a UE is provided. Accordingly, the UE can effectively identify a region matching the narrowband among the regions of the coreset.

A conventional New Radio (NR) network communication system includes a frequency band divided into a plurality of carrier frequency bands, and communication is performed using the plurality of carrier frequency bands. The carrier frequency band may be referred to as a cell and for data communication through the cell, a control channel is transmitted through each cell. Conventionally, cross-carrier scheduling techniques have been used in Long Term Evolution (LTE). However, a technology suitable for a communication environment using a plurality of cells such as NR is required.

In contrast, the present disclosure describes systems and methods for receiving a Physical Downlink Control Channel (PDCCH) from a Base Station (BS) using a particular cell in a cell group. In some cases, downlink Control Information (DCI) is obtained from the PDCCH. For example, the DCI includes scheduling information for a first cell and a second cell in a cell group. The user equipment receives a Physical Downlink Shared Channel (PDSCH) from a Base Station (BS) based on DCI using a specific cell and a plurality of cells.

Embodiments of the present disclosure include a Base Station (BS), wherein the BS performs scheduling in a cell group unit in communication using a plurality of cells, and transmits a Physical Downlink Control Channel (PDCCH) including Downlink Control Information (DCI) for the plurality of cells in the cell group to a User Equipment (UE) through a specific cell in the cell group. The UE acquires DCI from a PDCCH received through a specific cell, recognizes scheduling for each cell group, and receives a PDSCH corresponding thereto. Thus, the BS can select a cell group as a scheduling unit and cells within the cell group to conform to a network environment in which communication is performed using a large number of cells. In addition, the UE can accurately identify the selected cell group and cells in the cell group, thereby improving efficient use of communication resources and flexibility of the network.

The disclosure may be modified in numerous alternative forms, and thus specific embodiments will be illustrated in the drawings and described in detail. In this specification, when an element (or region, layer, component, etc.) is referred to as being "on," "connected to," or "coupled to" another element, it means that the element can be directly on/connected to/coupled to the other element or a third element can be disposed therebetween.

Like reference numerals may refer to like components throughout the specification and drawings. It should be noted that although the drawings are intended to illustrate actual relative dimensions of certain embodiments of the present disclosure, the present disclosure is not necessarily limited to the illustrated embodiments. The term "and/or" includes all combinations of one or more of which the associated configuration is definable.

It will be understood that, although the terms "first," "second," etc. may be used herein to describe various components, these components are not necessarily limited by these terms. These terms are only used to distinguish one element from another element. For example, a first component may be referred to as a second component, and similarly, a second component may be referred to as a first component, without departing from the scope of the inventive concept. Terms in the singular may include plural unless the context clearly indicates otherwise.

In addition, terms such as "below," "upper," and "above" may be used to describe the relationship between components illustrated in the figures. These terms are used as relative concepts and are described with reference to the directions indicated in the drawings. It should be understood that the terms "comprises," "comprising," or "having" are intended to specify the presence of stated features, integers, steps, operations, elements, components, or groups thereof, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or groups thereof.

Embodiments of the present disclosure include carrier services (NR) based on a New Radio (NR) network. For example, the operator service may be a wholesale operator service (WCS) such as a 3GPP release. The present disclosure is not limited to NR networks, and may be applied to other wireless communication systems, for example, cellular communication systems such as Long Term Evolution (LTE), LTE-advanced (LTE-a), wireless broadband (WiBro), global system for mobile communication (GSM), next-generation communication such as 6G), or short-range communication systems such as bluetooth and Near Field Communication (NFC), and the like.

In addition, the various functions described below may be implemented or supported by artificial intelligence techniques or one or more computer programs, each of which is formed from and embodied in a computer readable medium. The terms "application" and "program" refer to one or more computer programs, software components, sets of instructions, procedures, functions, objects, classes, instances, related data, or a portion thereof adapted for implementation in a suitable computer readable program code. The expression "computer readable program code" includes any type of computer code, including source code, object code, and executable code. The expression "computer-readable medium" includes any type of medium capable of being accessed by a computer, such as Read Only Memory (ROM), random Access Memory (RAM), a hard disk drive, a Compact Disc (CD), a Digital Video Disc (DVD), or any other type of memory. "non-transitory" computer-readable media do not include wired, wireless, optical, or other communication links that transmit transitory electrical or other signals. Non-transitory computer readable media include media that can permanently store data and media that can store data and later rewrite the data, such as rewritable optical disks or erasable memory devices.

In the embodiments described below, a hardware method is described as an example. However, embodiments include techniques that use both hardware and software, and thus, embodiments do not exclude software-based approaches.

The wireless communication system of the embodiment is described with reference to the accompanying drawings, in which the base station BS transmits scheduling information of each frequency band to the user equipment UE through efficient and effective resource allocation, and the UE can efficiently receive the scheduling information.

Fig. 1 is a block diagram illustrating a Wireless Communication System (WCS).

Referring to fig. 1, the wcs may include a Base Station (BS) 12 and a User Equipment (UE) 14.BS 12 refers to a fixed station that communicates with UE 14 and/or other BSs (not shown) and may exchange control information and data through communication with UE 14 and/or other cells (not shown). For example, the BS 12 may be referred to as a node B, an evolved node B (eNB), a next generation node B (gNB), a sector, a site, a Base Transceiver System (BTS), an Access Point (AP), a relay node, a Remote Radio Head (RRH), a Radio Unit (RU), a small cell, a wireless device, a device, and the like.

According to embodiments of the present disclosure, a wireless network may include a plurality of base stations and other network entities. A Base Station (BS) may be a station that communicates with a UE. Each base station may provide communication coverage for a particular geographic area. In 3GPP, the term "cell" can refer to a coverage area of a base station and/or a coverage area depending on the context in which the term is used. In an NR system, the terms "cell" and NB, next generation NB (gNB), 5G NB, access Point (AP), BS, NR BS, or Transmission Reception Point (TRP) may be interchangeable. In some examples, the cells may not necessarily be stationary, and the geographic area of the cells may move according to the location of the mobile base station. In some examples, the base stations may be interconnected with each other and/or to one or more other base stations or network nodes (not shown) in the wireless network through various types of backhaul interfaces, such as direct physical connections, virtual networks, and the like, using any suitable transmission network.

UE 14 may be stationary or mobile and may refer to any device capable of communicating with BS 12 to send data and/or control information to BS 12 and to receive data and/or control information from BS 12. For example, the UE 14 may be referred to as a terminal, a terminal equipment, a Mobile Station (MS), a Mobile Terminal (MT), a User Terminal (UT), a Subscriber Station (SS), a wireless communication device, a wireless device, a handheld device, and so on.

The BS 12 may provide wireless broadband access to UEs 14 within its coverage area 10. As an example shown in fig. 1, the BS 12 may divide the entire frequency band into first to fourth frequency bands b#1 to b#4 and communicate with the UE 14 using at least one of the first to fourth frequency bands b#1 to b#4. The BS 12 may use the first component carrier for communication in the first frequency band b#1, the second component carrier for communication in the second frequency band b#2, the third component carrier for communication in the third frequency band b#3, and the fourth component carrier for communication in the fourth frequency band b#4. The first to fourth frequency bands b#1 to b#4 may have first to fourth carrier bandwidths cbw#1 to cbw#4, and the first to fourth carrier bandwidths cbw#1 to cbw#4 may be the same, partially different, or completely different. However, in fig. 1, four frequency bands b#1 to b#4 are illustrated for understanding, but the scope of the disclosure is not limited thereto, and may be applied using more or less than four frequency bands. In some cases, BS 12 may manage the frequency bands as cells. Thus, the communication using the specific frequency band may be communication using a specific cell corresponding to the specific frequency band. Thus, the frequency band can be understood as the same concept as a cell.

According to an embodiment, when communication is performed using a plurality of cells, the BS 12 may perform scheduling in units of cell groups. In some cases, cells may be classified into at least one cell group, and BS 12 may perform scheduling on the cell group. In some embodiments, multiple cell groups may be configured, and BS 12 may perform scheduling on the cell groups. In some examples, scheduling of a cell group includes an operation of generating Downlink Control Information (DCI) by performing resource scheduling on a cell of the cell group and transmitting a Physical Downlink Control Channel (PDCCH) including the generated DCI through a specific cell. In addition, the specific cell refers to a cell selected for transmitting the PDCCH among a plurality of cells of a cell group, and may be selected according to various embodiments, details of which are described below.

According to an embodiment, the UE 14 may acquire DCI from the received PDCCH and identify whether scheduling of a cell group has been performed based on the acquired DCI. When the UE 14 recognizes that scheduling of a cell group has been performed, the UE 14 may receive a Physical Downlink Shared Channel (PDSCH) corresponding to the cell group through a plurality of cells based on the acquired DCI.

As an example shown in fig. 1, first to fourth cells respectively corresponding to the first to fourth frequency bands b#1 to b#4 are included in one cell group, and the BS 12 performs communication with the UE 14 using the first to fourth frequency bands b#1 to b#4. The BS 12 may transmit a PDCCH including DCI for the first to fourth cells to the UE 14 through a specific cell of the first to fourth cells. The UE 14 may identify that scheduling of a cell group has been performed based on DCI included in the received PDCCH, and may receive PDSCH transmitted through the first to fourth frequency bands b#1 to b#4 based on the DCI.

According to an embodiment, BS 12 and UE 14 may perform higher layer signaling (e.g., radio Resource Control (RRC) signaling or medium access control element (MAC CE)) for scheduling settings for a group of cells. In some cases, the scheduling settings for a cell group may be defined as settings between the BS 12 and the UE 14 for the UE 14 to identify at least one cell group, a plurality of cells included in the cell group, whether scheduling has been performed on the cell group, or the like. In some cases, higher layer signaling for scheduling settings for a cell group may include operations to receive performance information of the UE 14 by the BS 12. For example, the performance information of the UE 14 may include at least one of cells that the UE 14 can support, the number of cells that can support, and a method of selecting a particular cell. The performance information of the UE 14 may relate to scheduling for a group of cells. BS 12 may perform scheduling on the cell group based on the performance information of UE 14.

According to an embodiment, when communicating with the UE 14 using a plurality of cells, the BS 12 may transmit a PDCCH including DCI for the plurality of cells to a user through a specific cell among the plurality of cells, thereby efficiently using resources and improving network flexibility.

According to an embodiment, the UE 14 may recognize DCI included in a PDCCH received through a specific cell for a plurality of cells and receive PDSCH transmitted through the plurality of cells based on the DCI, thereby effectively supporting scheduling of a cell group by the BS 12.

Fig. 2 and 3 are block diagrams showing implementation methods of the BS 100 and the UE 150, respectively. The implementation methods of BS 100 and UE 150 of fig. 2 and 3 may be applied to BS 12 and UE 14 of fig. 1, respectively.

Referring to fig. 2, the bs 100 may include a controller 110, a memory 120, a processing circuit 130, a plurality of transceivers 142_1 to 142_j, and a plurality of antennas 144_1 to 144_j.

Memory 120 refers to a memory device. Examples of memory devices include Random Access Memory (RAM), read Only Memory (ROM), or a hard disk. Examples of memory devices include solid state memory and hard drives. In some examples, memory is used to store computer-readable, computer-executable software comprising instructions that, when executed, cause a processor to perform the various functions described herein. In some cases, the memory contains, among other things, a basic input/output system (BIOS), where the BIOS controls basic hardware or software operations, such as interactions with peripheral components or devices. In some cases, the memory controller operates the memory cells. For example, the memory controller may include a row decoder, a column decoder, or both. In some cases, memory cells within a memory store information in the form of logical states.

The transceiver 142 may communicate bi-directionally via an antenna, a wired link, or a wireless link. For example, a transceiver may represent a wireless transceiver and may be in two-way communication with another wireless transceiver. The transceiver may also include or be connected to a modem to modulate packets and provide modulated packets for transmission and demodulate received packets. In some examples, the transceiver may be tuned to operate at a specified frequency. For example, the modem may configure the transceiver to operate at a specified frequency and power level based on the communication protocol used by the modem. Accordingly, the transceivers 142_1 to 142_j may receive RF signals transmitted from UEs within coverage through the antennas 144_1 to 144_j. The transceivers 142_1 to 142_j may down-convert the received RF signals to generate Intermediate Frequency (IF) signals or baseband signals.

The antennas 144_1 to 144_j refer to wireless devices that may include a single antenna or more than one antenna. For example, an antenna may be capable of concurrently transmitting or receiving multiple wireless transmissions. In some cases, the wireless communication device may include an antenna array.

The processing circuit 130 may generate the data signal by filtering, decoding, and/or digitizing the IF signal or the baseband signal. The controller 110 may perform additional processing on the data signal. In addition, the processing circuit 130 may receive data signals from the controller 110. In some cases, processing circuitry 130 may encode, multiplex, and/or convert the received data signals to analog.

The transceivers 142_1 to 142_j may up-convert the IF signals or baseband signals output from the processing circuit 130 and transmit the signals as RF signals to the UE through the antennas 144_1 to 144_j.

According to some embodiments of the present disclosure, the controller 110 may control the BS 100 to perform NR network-based communication, and may include a scheduler 112 that performs scheduling on a cell group including a plurality of cells.

According to an embodiment, the scheduler 112 may perform resource scheduling for transmitting PDSCH for each cell, and may generate DCI including a resource scheduling result. The scheduler 112 may control the processing circuit 130, the transceivers 142_1 to 142_j, and the antennas 144_1 to 144_j to transmit a PDCCH including DCI to the UE through a specific cell of the plurality of cells.

According to an embodiment, the scheduler 112 may include scheduling related information for a cell group in at least one of a plurality of fields of the DCI. The UE may identify whether scheduling has been performed on at least one of the cell group and a plurality of cells included in the cell group based on the scheduling related information for the cell group. In some cases, at least one field of DCI for transmitting scheduling-related information for a cell group may include a reserved field and/or a field that is not used in the current case, and thus the field does not transmit information. In some cases, the DCI may include a newly defined field to transmit scheduling-related information for a cell group. In addition, the DCI may be configured to have an optimized format for providing scheduling related information for a cell group.

The controller 110 may execute programs and/or processes stored in the memory 120 to perform overall control operations for the BS 100. In some cases, the scheduler 112 may be stored in the memory 120 as program code that is executed to perform scheduling operations. When the operation of the scheduler 112 can be performed, the controller 110 accesses the memory 120 to execute the stored program code, according to some embodiments of the present disclosure.

Referring to fig. 3, the ue 150 may include a controller 160, a memory 170, a processing circuit 180, a transceiver 192, and a plurality of antennas 194_1 to 194_h.

The transceiver 192 may receive RF signals transmitted by the BS through the antennas 194_1 to 194—h. In some cases, the BS includes operations as described with reference to fig. 1 and 2. Transceiver 192 may down-convert the received RF signal to an IF signal or a baseband signal. The processing circuit 180 may generate the data signal by filtering, decoding, and/or digitizing the IF signal or the baseband signal. In some cases, the controller 160 may perform additional processing on the data signals.

In addition, the processing circuit 180 may receive data signals from the controller 160. The processing circuitry 180 may encode, multiplex, and/or convert the received data signals to analog. The transceiver 192 up-converts the IF signal or the baseband signal output from the processing circuit 180 and transmits the signal as an RF signal through the antennas 194_1 to 194_h.

According to an embodiment, the controller may control the UE to communicate over the NR network and may include a decoding circuit 162 that identifies whether scheduling has been performed on the cell group. In some cases, the identification is based on a PDCCH received from the BS, and DCI included in the PDCCH is processed based on the identification result.

According to embodiments of the present disclosure, the decoding circuit may perform blind decoding on the PDCCH to obtain DCI. In some cases, the decoding circuit 162 identifies whether scheduling has been performed on the cell group based on the acquired DCI. As described with reference to fig. 2, the DCI may include scheduling-related information for a cell group. The decoding circuit 162 can identify whether scheduling has been performed on the cell group by interpreting scheduling related information for the cell group based on the scheduling setting for the cell group. Further, the decoding circuitry 162 may identify a cell group and/or a plurality of cells for which the DCI is acquired based on the scheduling related information for the cell group being valid.

According to an embodiment, the controller 160 may receive PDSCH corresponding to a cell group (or PDSCH corresponding to a plurality of cells respectively) based on the acquired DCI control processing circuit 180, transceiver 192, and antennas 194_1 to 194_h.

The controller 160 may execute programs and/or processes stored in the memory 170 to perform control operations for the UE 150. According to some embodiments, the decoding circuit 162 may be stored in the memory 170 as program code that is executed to support scheduling for cell groups according to embodiments, and the controller 160 may access the memory 170 to execute the stored program code to perform the operations of the decoding circuit 162.

Fig. 4A shows a structure of a time-frequency domain as a radio resource region in a wireless communication system. Fig. 4B illustrates a slot structure in a wireless communication system. Fig. 4C shows an implementation example of the bandwidth parts bwp#1 to bwp#3 in the first frequency band b#1 of the wireless communication system. Fig. 4D is an example of coreset in a wireless communication system. Fig. 4E shows the structure of coreset in the wireless communication system.

Referring to fig. 4A, a horizontal axis may indicate a time domain and a vertical axis may indicate a frequency domain. The smallest transmission unit in the time domain is an Orthogonal Frequency Division Multiplexing (OFDM) symbol (symbol). As in the example shown in fig. 4A, N may be aggregated _symb The OFDM symbols 202 to configure one slot 206 and two slots may be aggregated to configure one subframe 205. For example, the length of the slot 206 may be 0.5ms and the length of the subframe 205 may be 1.0ms. However, this is an exemplary embodiment, the length of the slot 206 may vary according to the configuration of the slot 206, and the number of slots 206 included in the subframe 205 may vary according to the length of the slot 206. In addition, a time-frequency domain may be defined in the NR network based on the slot 206. In addition, the radio frame 214 may be a time domain unit consisting of 10 subframes 205.

According to an embodiment, the smallest transmission unit in the frequency domain is a subcarrier. In some cases, the system transmission bandwidth may include N _BW Subcarriers 204. The basic unit of resources in the time-frequency domain is a Resource Element (RE) 212 that can be represented by an OFDM symbol index and a subcarrier index. Resource Block (RB) 208 may be defined by N in the time domain _symb Each successive OFDM symbol 202 and N in the frequency domain _RB And successive subcarriers 210. Thus, one RB 208 may include (N _symb *N _RB ) And RE 212. The RB pair is a unit of two cascaded RBs on the time axis, and may include (N _symb *2N _RB ) And RE 212.

As an example shown in fig. 4A, resources in the time-frequency domain may be divided into a plurality of cells, and the cells may be classified into at least one cell group. When the BS performs scheduling for a cell group, a PDCCH including DCI with scheduling information for a plurality of cells in the cell group may be transmitted to the UE through a specific cell in the cell group. The UE may receive PDSCH transmitted through the plurality of cells based on DCI in the PDCCH received from the specific cell. The BS transmits DCI including scheduling-related information for a cell group to the UE through a specific cell so that the UE can accurately recognize scheduling of the cell group performed in the BS and adaptively perform operations suitable therefor.

As an example shown in fig. 4B, one radio frame 300 may be defined as 10ms, a subframe 301 may be defined as 1ms, and the radio frame 300 may include a total of ten subframes 301. In some examples, slots 302 or 303 may be defined by 14 OFDM symbols (i.e., the number of symbols per slot). Subframe 301 may include a slot 302 or a plurality of slots 303. The number of slots 302 and 303 of each subframe 301 may be different according to the set value μ (304 and 305) of the subcarrier spacing and the number of symbols included in the slots 302 and 303. According to fig. 4B, the setting values 304 and 305 are subcarrier spacing setting values. For example, one subframe 301 includes one slot 302 when the subcarrier spacing setting value is 304, and one subframe 301 may include two slots 303 when the subcarrier spacing setting value is 305.

According to an embodiment of the present disclosure, the number of slots per subframe may vary according to a set value of a subcarrier interval, and the number of slots per frame may vary. The number of slots per subframe and the number of slots per frame according to the set value for each subcarrier spacing may be defined by table 1.

TABLE 1

In addition, the number of slots per subframe may vary according to the number of symbols included in one slot. For example, the set value may be any one of 0, 1, 2, 3, 4, and the value may refer to frequencies of 15kHz, 30kHz, 60kHz, 120kHz, and 240 kHz.

According to an embodiment, the plurality of frequency bands and the number of frequency bands may vary according to the set value of the subcarrier spacing. As a result, the cell group used to divide the plurality of cells may also vary. The BS may perform scheduling setting with the UE for a cell group to appropriately perform scheduling for a plurality of cells that vary according to the set value of the subcarrier interval. In some cases, the BS includes operations as described with reference to fig. 1 and 2. In some cases, the UE includes operations as described with reference to fig. 1 and 3.

Referring to fig. 4C, the first carrier bandwidth cbw#1 of the first band b#1 may include first to third bandwidth parts bwp#1 to bwp#3. However, this is merely an example, and the first carrier bandwidth b#1 may include more or less than three bandwidth portions. In addition, the first frequency band b#1 may correspond to the first frequency band b#1 (as shown in fig. 1), and each of the first to fourth frequency bands b#1 to b#4 may include the same number or different numbers of bandwidth parts. The description of the first frequency band b#1 given below may also be applied to the second to fourth frequency bands b#2 to b#4 as described with reference to fig. 1.

In addition, information including a bandwidth part identifier, a bandwidth part position, a subcarrier spacing, a cyclic prefix, and the like may be separately set for the first to third bandwidth parts bwp#1 to bwp#3. The BS may provide the UE with information about the first to third bandwidth parts bwp#1 to bwp#3 of the first frequency band b#1 through higher layer signaling (e.g., RRC signaling). Therefore, any one of the first to third bandwidth parts bwp#1 to bwp#3 may be activated. The decision to activate the set bandwidth portion may be provided semi-statically from the BS to the UE through RRC signaling or may be provided dynamically from the BS to the UE through MAC CE or DCI.

According to an embodiment, the BS may activate any one of the first to third bandwidth parts bwp#1 to bwp#3 included in the first frequency band b#1 and transmit a PDCCH including DCI for a cell group to the UE through a sub-band matched with the activated bandwidth part according to an embodiment.

Referring to fig. 4D, two CORESETs (i.e., CORESET #1 and CORESET # 2) may be fully set in bandwidth 410 on the frequency axis and in time slot 420 on the time axis. CORESET #1 and CORESET #2 may be set in a certain frequency resource 403 within bandwidth 410 on the frequency axis. CORESET #1 and CORESET #2 may be set as one or more OFDM symbols on a time axis, which may be defined as the duration 404 of CORESET #1 and CORESET #2. For example, the first CORESET coreset#1 may be set to have a length of two symbols, and the second CORESET coreset#2 may be set to have a length of one symbol.

Reference to fig. 4E,coreset CORESET may include "x" physical resource blocks (i.e., PRBs) on the frequency axis and two OFDM symbols on the time axis. In some cases, coreset may include multiple Resource Element Groups (REGs). For example, one Resource Element Group (REG) bundle may include two REGs. As an example, the REG may include 12 resource elements on the frequency axis and 1 OFDM symbol on the time axis. For example, a Control Channel Element (CCE) may include six REGs. In some examples, the REGs included in CCE #1 through CCE #16 may be "non-interleaved CCE-to-REG mapped". In some examples, the REGs included in CCE #1 through CCE #16 may be "interleaved CCE-to-REG mapped".

According to an embodiment, an Aggregation Level (AL) may indicate the number of CCEs allocated to the PDCCH. In addition, the number of candidates may vary according to the aggregation level AL. For example, in case the aggregation level AL is 1, the first CCE (# 1), the fifth CCE (# 5), the ninth CCE (# 9), and the thirteenth CCE (# 13) may correspond to the first to fourth PDCCH candidates c#1, c#2, c#3, and c#4, respectively. Similarly, when the aggregation level AL is 2, the first and second CCEs (# 1 and # 2) may correspond to the fifth PDCCH candidate c#5, and the ninth and tenth CCEs (# 9 and # 10) may correspond to the sixth PDCCH candidate c#6. In addition, when the aggregation level AL is 4, the first to fourth CCEs #1, #2, #3, and #4 may correspond to the seventh PDCCH candidate c#7. The PDCCH candidates may refer to targets for blind decoding of the PDCCH transmitted from the BS (or DCI acquired from the PDCCH) by the UE, and the aggregation level AL may be related to the search space configuration. The search space may refer to PDCCH candidates that may exist in one aggregation level AL. There may be multiple search spaces in one coreset, and multiple coresets may be configured in the UE.

According to embodiments of the present disclosure, the UE may determine PDCCH candidates in consideration of scheduling of the BS for a cell group. For example, the UE may determine the PDCCH candidates by using CCEs existing in at least one coreset configured for a specific cell among a plurality of cells included in the cell group. In some cases, the UE may exclude CCEs present in CORESET configured in other cells than the specific cell from the monitoring target for blind decoding, thereby improving the blind decoding efficiency of the UE.

According to an embodiment, the UE may determine PDCCH candidates to blindly decode a coreset having a specific index in a specific cell of a cell group, a coreset associated with a search space having a specific index, or a PDCCH including DCI having a specific search space type or a specific format.

According to an embodiment, the BS may generate DCI by selecting any one of carrier indexes respectively corresponding to cells included in a cell group, and transmit a PDCCH including the generated DCI to the UE through a specific cell in the cell group. The UE may determine CCE indexes in the search space based on carrier indexes included in the DCI. Fig. 5 depicts a BS selecting a carrier index.

Fig. 5 is a flow chart illustrating a method of operating a wireless communication system. The wireless communication system may include a BS 510 and a UE 520. In some cases, the BS includes operations as described with reference to fig. 1 and 2. In some cases, the UE includes operations as described with reference to fig. 1 and 3.

Referring to fig. 5, in operation S100, a BS 510 and a UE 520 may perform higher layer signaling for scheduling settings for a cell group. In some cases, the BS 510 may perform setup for the UE 520 through higher layer signaling to identify at least one schedulable cell group, a plurality of cells included in the cell group, and whether scheduling has been performed on the cell group. In some cases, the UE 520 may provide the performance information of the UE 520 to the BS 510 through higher layer signaling. The performance information of the UE 520 may include at least one of cells supportable by the UE 520, the number of supportable cells, and a method of selecting a specific cell. In addition, the performance information of the UE 520 may also include information about the UE 520 that the BS 510 may consider for scheduling cell groups.

In operation S110, the BS 510 may perform scheduling on the cell group. According to an embodiment, the BS 510 may perform scheduling including resource allocation for PDSCH to be transmitted through cells in the cell group. In some cases, the BS 510 may perform scheduling on the cell group based on the performance information of the UE 520 provided in operation S100. BS 510 may perform scheduling on cells that UE 520 may support or cell groups that match the number of supportable cells based on the performance information of UE 520. Further, the BS 510 may select a specific cell in the cell group based on the performance information of the UE 520, and the BS 510 may generate DCI including the scheduling result of operation S110 and scheduling related information for the cell group. According to an embodiment, the BS 510 may schedule a PDCCH including DCI and corresponding to a cell group based on a selected cell. Optionally, scheduling the PDCCH may include scrambling the PDCCH with a particular Radio Network Temporary Identifier (RNTI), wherein the RNTI indicates that the scheduling is used on scheduling for the group of cells.

In operation S120, the BS 510 may transmit a PDCCH including DCI for a plurality of cells to the UE 520 through a specific cell of the cell group. According to an embodiment, the BS 510 may select any cell among cells in the cell group as a specific cell through the first cell selection method. In some cases, the BS 510 may select a predefined cell among cells in the cell group as a specific cell through the second cell selection method. In some cases, there may be a plurality of predefined cells, and a particular cell may be selected from among the predefined cells. For example, the BS 510 may select a specific cell by using any one of the first cell selection method and the second cell selection method based on the performance information of the UE 520. For example, a first cell selection method may be selected when the performance of the UE 520 is good, and a second cell selection method may be selected when the performance of the UE 520 is relatively poor.

In operation S130, the UE 520 may acquire DCI for a cell group from the PDCCH. According to an embodiment, the UE 520 may obtain DCI for a cell group by performing blind decoding on PDCCH candidates in at least one coreset configured for a specific cell. As described above, DCI for a cell group may include scheduling information for cells in the cell group.

In operation S140, the UE 520 may identify whether scheduling has been performed on the cell group based on the DCI. In an embodiment, the DCI may include scheduling-related information for a cell group, and the UE 520 may identify whether the BS has performed scheduling for the cell group based on the scheduling-related information for the cell group. In addition, the UE 520 may identify a cell group on which scheduling has been performed and at least one of a plurality of cells in the cell group based on scheduling related information for the cell group. In some cases, the UE 520 may identify whether scheduling has been performed on the cell group based on a Radio Network Temporary Identifier (RNTI) used when blind decoding of the PDCCH performed in operation S130 is successful. Thus, when the corresponding RNTI is identical to the specific RNTI, the UE 520 may identify that scheduling for the cell group has been performed, and thereafter, the UE 520 may identify the cell group for which scheduling has been performed and at least one of a plurality of cells in the cell group based on scheduling related information about the cell group.

In operation S150, the BS 510 may transmit a PDSCH through a cell of the cell group. In operation S160, the UE 520 may receive a PDSCH based on the DCI acquired in operation S130.

Fig. 6A to 6C show the first cell group cg#1, and fig. 6D shows the first cell group cg#1 and the second cell group cg#2. However, fig. 6A to 6D are only exemplary embodiments, and the embodiments are not limited thereto. The cell group and the plurality of cells included in the cell group may be set in various manners.

Referring to fig. 6A, the first Cell group cg#1 may include first cell#1 to fourth cell#4. The BS may transmit a PDCCH including DCI generated by performing scheduling on the first Cell group cg#1 to the UE through the first Cell cell#1, which is a specific Cell, at the nth Slot slot#n. The DCI may include scheduling-related information so that the UE may identify scheduling for the first cell group cg#1. The scheduling-related information may include at least one of information indicating the first Cell group cg#1 and information indicating the first Cell cell#1 to the fourth Cell cell#4 included in the first Cell group cg#1.

The BS may transmit PDSCH to the UE through the first to fourth cells cell#1 to cell#4 in the (n+k) th Slot slot# (n+k). In some cases, the operations of the BS and the UE have been described with reference to fig. 1 to 3. The UE may receive PDSCH through the first cell#1 to the fourth cell#4 based on DCI acquired from the PDCCH of the nth slot#n.

Referring to fig. 6b, the bs may perform scheduling on remaining cells cell#1 to cell#3 except for the fourth Cell cell#4 among the first Cell group cg#1 to the fourth Cell cell#4. According to an embodiment, when the BS performs scheduling on the first Cell group cg#1, a portion of the first Cell group cg#1 (e.g., the fourth Cell cell#4) may be excluded from the scheduling. The BS may perform scheduling on the fourth Cell #4 separately from scheduling on the first Cell group CG # 1.

The BS may transmit a PDCCH including DCI generated by performing scheduling on the first Cell group cg#1 to the UE through the first Cell cell#1, which is a specific Cell, in the nth Slot slot#n. In some examples, the BS may transmit a PDCCH including DCI generated by performing scheduling on the fourth cell#4 to the UE through the fourth cell#4 in the nth Slot slot#n. The UE may identify scheduling of the first Cell group cg#1 excluding the fourth Cell cell#4 from DCI in the PDCCH received through the first Cell cell#1.

The BS may transmit PDSCH to the UE through the first to fourth cells cell#1 to cell#4 in the (n+k) th Slot slot# (n+k). The UE may receive PDSCH through the first to third cells cell#1 to cell#3 based on DCI acquired from the PDCCH through the first Cell cell#1, and may receive PDSCH through the fourth cell#4 based on DCI acquired from the PDCCH through the fourth Cell cell#4.

Referring to fig. 6c, the bs may perform scheduling on remaining cells cell#1 to cell#3 except for the fourth Cell cell#4 among the first Cell cell#1 to the fourth Cell cell#4 of the first Cell group cg#1. According to an embodiment, when scheduling is performed on the first cell group cg#1, the BS may exclude a portion of the first cell group cg#1 by considering at least one of a communication environment between the BS and the UE, an amount of data to be transmitted, and a supportable frequency band of the UE. As an example shown in fig. 6C, the fourth Cell cell#4, which is a Cell excluded from scheduling, may be a dormant Cell. In contrast to fig. 6B, the BS may not perform scheduling on the fourth Cell cell#4.

Referring to fig. 6D, the first Cell group cg#1 may include a first Cell cell#1 and a second Cell cell#2, and the second Cell group cg#2 may include a third Cell cell#3 and a fourth cell#4. The BS may transmit a PDCCH including DCI generated by performing scheduling on the first Cell group cg#1 to the UE through the first Cell cell#1, which is a specific Cell, in the nth Slot slot#n. The BS may transmit a PDCCH including DCI generated by performing scheduling on the second Cell group cg#2 to the UE through the third Cell cell#3, which is a specific Cell, in the nth Slot slot#n.

According to an embodiment of the present disclosure, DCI of a PDCCH through a first Cell cell#1 may include scheduling-related information for a first Cell group cg#1, and DCI of a PDCCH through a third Cell cell#3 may include scheduling-related information for a second Cell group cg#2. The UE may identify the schedule for the first cell group cg#1 and the second cell group cg#2 based on the corresponding schedule-related information.

As an example shown in fig. 6D, the BS may transmit PDSCH to the UE through the first to fourth cells cell#1 to cell#4 in the (n+k) th slot# (n+k). The UE may receive PDSCH through the first Cell cell#1 and the second Cell cell#2 based on DCI acquired from the PDCCH through the first Cell cell#1, and may receive PDSCH through the third Cell cell#3 and the fourth Cell cell#4 based on DCI acquired from the PDCCH through the third Cell cell#3.

Fig. 7A to 7D show scheduling related information for a cell group. However, fig. 7A to 7D show examples of scheduling related information for a cell group, but the embodiment is not limited thereto.

Referring to fig. 7a, dci may include a cell group indicator field. For example, the cell group indicator field may include y bits of information. According to an embodiment, the BS may set a plurality of cell groups in a scheduling setting with the UE for the cell groups, wherein each cell group includes a plurality of cells. The cell group indicator field according thereto is described with reference to fig. 7B. According to an embodiment, the BS may set a plurality of cells in a scheduling setting with the UE for a cell group, and a cell group indicator field according thereto is described with reference to fig. 7C. According to an embodiment, the BS may set a plurality of cell groups and a plurality of cells included in each of the plurality of cell groups in a scheduling setting with the UE for the cell groups. The cell group indicator field according thereto is described with reference to fig. 7D.

As an example shown in fig. 7B, the first cell group cg#11 to the fourth cell group cg#41 may be configured by a scheduling setting for cell groups between the BS and the UE. Although not shown in fig. 7B, a plurality of cells included in each of the first cell group cg#11 to the fourth cell group cg#41 may also be configured by a scheduling setting for cell groups between the BS and the UE. For example, the information of the cell group indicator field may be in the form of a code, and may be composed of 2 bits to indicate four cell groups cg#11 to cg#41.

As in the example in fig. 7B, a code having a value of 00 may indicate the first cell group cg#11, a code having a value of 01 may indicate the second cell group cg#21, a code having a value of 10 may indicate the third cell group cg#31, and a code having a value of 11 may indicate the fourth cell group cg#41.

According to an embodiment of the present disclosure, the BS may select any one of the cell groups cg#11 to cg#41 and perform scheduling on the cell group. In some cases, the BS may inform the UE of the scheduled cell group. The UE may identify a cell group scheduled from the BS by referring to a code of a cell group indicator field of the DCI.

Referring further to fig. 7C, the first through sixth cells c#11 through c#61 may be configured by scheduling settings for cell groups between the BS and the UE. The information of the cell group indicator field may be in a bitmap format and may be composed of 6 bits to indicate six cells c#11 to c#61.

As an example in fig. 7C, bits of the bitmap may indicate the first cell c#1 to the sixth cell c#6, respectively. The bitmap having a value of 000111 may indicate the first to third cells c#11 to c#31, and the first to third cells c#11 to c#31 may be included in the first cell group cg#12. A bitmap of value 111000 may indicate the fourth cell c#41 to the sixth cell c#61, and the fourth cell c#41 to the sixth cell c#61 may be included in the second cell group cg#22.

According to an embodiment, the BS may select at least two of the cells c#11 to c#61 and perform scheduling on cell groups cg#12 and cg#22 including the selected cells, and may individually notify the UE of the scheduled cells. The UE may identify a cell group scheduled from the BS by referring to a bitmap of a cell group indicator field of the DCI.

Referring to fig. 7D, the first cell group cg#13 and the second cell group cg#23 may be set by scheduling settings for cell groups between the BS and the UE, and the first cell c#12 to the fourth cell c#42 included in the first cell group cg#13 are set. In addition, the fifth cell c#52 to the seventh cell c#72 included in the second cell group cg#23 may be set. The information of the cell group indicator field takes the form of a combination of a code and a bitmap. For example, the information may be composed of 5 bits to indicate the cells c#12 to c#72 included in each of the two cell groups cg#13 and cg#23. In some cases, the most significant bits may indicate a cell group as a code, while the least significant bits may indicate a cell as a bitmap.

For example, information of the cell group indicator field having a value of "01111" may indicate that the first to fourth cells c#12 to c#42 are scheduled in the first cell group cg#13, and information of the cell group indicator field having a value of 00111 may indicate that the first to third cells c#12 to c#32 are scheduled in the first cell group cg#13. In addition, information of the cell group indicator field having a value 10111 may indicate that the fifth cell c#52 to the seventh cell c#72 are scheduled in the second cell group cg#23, and information of the cell group indicator field having a value 10011 may indicate that the fifth cell c#52 and the sixth cell c#62 are scheduled in the second cell group cg#23.

As an example shown in fig. 7D, the BS may select at least two of the cell groups cg#13 and cg#23 and the plurality of cells c#12 to c#42 and c#52 to c#72 in the cell group, perform scheduling thereon, and may notify the UE of the scheduled cell in the cell group. Cells not selected from the cell group may be cells excluded from scheduling for the cell group. The UE may identify a cell in a cell group scheduled from the BS by referring to a combination of a code and a bitmap of a cell group indicator field of the DCI.

Fig. 8 and 9 are diagrams showing scheduling related information for a cell group. Referring to fig. 8, dci may include a carrier indicator field. The carrier indicator field may include a cell group indicator. In some cases, the BS may generate a cell group indicator indicating a plurality of cells or a cell group including the plurality of cells scheduled together with a specific cell, wherein the specific cell is a cell transmitting a PDCCH including DCI. The BS may include the generated cell group indicator in a carrier indication field of the DCI. The UE may refer to a carrier indicator field of the DCI to identify a scheduled cell or a scheduled cell group. The embodiments described above with reference to fig. 7A to 7D may be applied to a cell group indicator to be included in a carrier indicator field.

With further reference to fig. 9, the dci may include a time domain resource allocation field. The table of time domain resource allocation fields may be configured by higher layer signaling. According to an embodiment, the time domain resource allocation field may be set based on a schedule for the cell group. In some cases, the time domain resource allocation field may include information indicating a scheduled cell group or a scheduled cell. In addition, the time domain resource allocation field may include time domain resource allocation information corresponding to scheduling for a cell group. The UE may refer to a time domain resource allocation field of the DCI to identify a scheduled cell or a set of scheduled cells.

Fig. 10A and 10B are flowcharts illustrating an operation method of the BS for selecting a specific cell. In fig. 10A and 10B, it is assumed that the BS performs scheduling on the cell group.

Referring to fig. 10A, in operation S200A, the BS may select a specific cell for transmitting the PDCCH among a cell group. In order to transmit a PDCCH including DCI generated by scheduling a cell group, the BS may select any one of cells included in the cell group as a specific cell. In some cases, the cells included in the cell group do not include cells excluded from scheduling (i.e., dormant cells). Various embodiments of a cell selection method in which a BS selects a specific cell may exist.

For example, the BS may select any cell among cells of the cell group as a specific cell based on the first cell selection method. As an example, based on the second cell selection method, the BS may select, as the specific cell, any one of a plurality of cells set as the specific cell through scheduling settings or any one of a plurality of cells set as the specific cell candidate. The BS may select a specific cell based on any one of the first cell selection method and the second cell selection method.

In operation S210a, the BS may transmit a PDCCH to the UE using a specific cell.

Referring to fig. 10B, in operation S200B, the BS may receive performance information of the UE indicating a cell selection method. In some cases, the BS may receive performance information of the UE indicating a cell selection method suitable for the UE's own performance through higher layer signaling.

In operation S210b, the BS may select a specific cell for transmitting the PDCCH from the cell group based on a cell selection method indicated by the performance information of the UE. The BS may select a cell selection method indicated in the performance information of the UE among the first cell selection method and the second cell selection method described with reference to fig. 10A and select a specific cell based thereon. In operation S220b, the BS may transmit the PDCCH to the UE using a specific cell.

Fig. 11A to 11C are flowcharts showing an operation method for a UE to recognize whether scheduling has been performed on a cell group. In fig. 11A to 11C, it is assumed that the BS performs scheduling on the cell group.

Referring to fig. 11A, in operation S300a, the UE may acquire information on resources allocated for PDCCH transmission from DCI. According to an embodiment, the information on the allocated resources may include at least one of an index of a coreset to which the PDCCH is transmitted and an index of a search space associated with the coreset to which the PDCCH is transmitted.

In operation S310a, the UE may identify scheduling for a cell group based on the information acquired in operation S300 a. In some cases, the UE may identify scheduling of the cell group based on at least one of whether an index of coreset included in the acquired information corresponds to a particular index of coreset and whether an index of the search space corresponds to a particular index of the search space. At least one of the specific index of coreset and the specific index of the search space may be set by a scheduling setting for a cell group. Thus, when the index of coreset included in the acquired information corresponds to a specific index of coreset, or when the index of search space corresponds to a specific index of search space, the UE may recognize that scheduling has been performed on the cell group.

In operation S320a, the UE may receive a PDCSH corresponding to a cell group by considering scheduling for the cell group. That is, the UE may receive PDSCH transmitted from a plurality of cells of a cell group based on DCI.

With further reference to fig. 11B, in operation S300B, the UE may acquire a format of DCI from the DCI. In operation S310b, the UE may identify scheduling for a cell group based on the format of the acquired DCI. In some cases, the UE may identify a schedule for the cell group based on whether the format of the acquired DCI corresponds to a particular format of the DCI. The specific index of DCI may be set by a scheduling setting for a cell group. Thus, when the format of the acquired DCI corresponds to a specific format of the DCI, the UE may recognize that scheduling has been performed on the cell group. In operation S320b, the UE may receive a PDCSH corresponding to the cell group by considering scheduling for the cell group.

Referring further to fig. 11C, in operation S300C, the UE may perform blind decoding on a PDCCH transmitted from the BS through a specific cell. In operation S310c, the UE may identify scheduling for a cell group based on an RNTI used when blind decoding is successful. In some cases, the UE may identify a schedule for a cell group based on whether the corresponding RNTI corresponds to a particular RNTI. The specific RNTI may be configured by a scheduling setting for a cell group. When the corresponding RNTI corresponds to the specific RNTI, the UE may recognize that scheduling has been performed on the cell group. In operation S320c, the UE may receive a PDCSH corresponding to the cell group by considering scheduling for the cell group.

Fig. 12A is a flowchart showing an operation method of the UE for identifying whether scheduling for a cell group is performed, and fig. 12B is a flowchart showing a detailed operation method of the UE in operation S420 of fig. 12A.

Referring to fig. 12A, in operation S400, the UE may determine whether a PDCCH is received through a primary cell. The primary cell may refer to a cell used in an initial connection establishment procedure or a connection re-establishment procedure with the BS.

When operation S400 is yes, the UE may identify whether scheduling is for a cell group in operation S410. Thus, when receiving a PDCCH through a primary cell, the UE may identify whether the corresponding PDCCH includes DCI conforming to scheduling for a cell group. Operation S410 may be configured to be performed when a PDCCH is received through a primary cell through scheduling settings for a cell group.

When operation S410 is yes, the UE may receive a PDCSH corresponding to the cell group by considering scheduling of the cell group in operation S420.

When operation S400 or operation S410 is no, the UE may receive PDSCH from each cell by considering scheduling for each cell in operation S430. Thus, the UE may receive PDCCHs from the respective cells, acquire DCI from the received PDCCHs, and receive PDCSH from the respective cells based on the acquired DCI.

Referring to fig. 12B, in operation S421, the UE may identify secondary cells included in a cell group. In operation S422, the UE may simplify the PDCCH monitoring operation by considering the identified secondary cell. In some cases, the UE may recognize that the PDCCH is not transmitted from the BS through the secondary cell included in the cell group, and thus, the UE may exclude CCEs existing in coreset configured in the secondary cell from the monitoring target for blind decoding. Thus, the UE may perform blind decoding on at least one coreset configured in the primary cell.

Fig. 13 is a flowchart illustrating an operation method of the UE performing blind decoding. In fig. 13, it is assumed that the BS performs scheduling on a cell group.

Referring to fig. 13, in operation S500, the UE may determine PDCCH candidates by considering scheduling for a cell group. Because the PDCCH is transmitted through a specific cell of a cell group scheduled by the BS, the UE may determine a PDCCH candidate based on at least one coreset configured for the specific cell. In some cases, the UE may count the number of non-overlapping CCEs to determine PDCCH candidates.

In operation S510, the UE may perform blind decoding using the determined PDCCH candidate. The UE may acquire DCI from the PDCCH through a specific cell upon successful blind decoding.

Fig. 14 is a flowchart illustrating an operation method of the BS for determining the carrier index. In fig. 14, it is assumed that the BS performs scheduling on a cell group.

Referring to fig. 14, in operation S600, the BS may select a cell for determining a carrier index among a cell group. Carrier indexes may be used when determining CCE indexes in a search space for blind decoding. According to an embodiment, the BS may select a specific cell among the cell groups as a cell for determining the carrier index. In some cases, the BS may select a cell having the largest carrier index or the smallest carrier index among a plurality of cells of a cell group as a cell for determining the carrier index in the cell group.

In operation S610, the UE may generate DCI including a carrier index having a value corresponding to the selected cell.

Fig. 15 is a flowchart illustrating an operation method of the UE for determining the size of the frequency domain resource allocation field. According to an embodiment, the BS performs scheduling on the cell group.

Referring to fig. 15, in operation S700, the UE may determine a size of a frequency domain resource allocation field in DCI for a cell group. In some cases, the UE may determine the size of the frequency domain resource allocation field based on a cell having a largest bandwidth portion or carrier bandwidth among a plurality of cells of the cell group. According to an embodiment, the UE may determine the size of the frequency domain resource allocation field based on a cell having a maximum bandwidth portion or carrier bandwidth among a plurality of cells of the cell group and at least one cell (not included in the cell group) transmitting the PDCCH. In operation S710, the UE may receive PDSCH transmitted from a plurality of cells of a cell group or at least one cell (not included in the cell group) and transmit PDCCH based on the determined size of the frequency domain resource allocation field.

Fig. 16 is a conceptual diagram illustrating an internet of things (IoT) network system 1000 to which embodiments are applied.

Referring to fig. 16, ioT network system 1000 may include multiple IoT devices (e.g., home accessory 1100, home appliance 1120, entertainment apparatus 1140, and vehicle 1160), access point AP 1200, gateway 1250, wireless network 1300, and server 1400.IoT may refer to a network that uses wired/wireless communication between objects.

Each of IoT devices 1100, 1120, 1140, and 1160 may form a group according to the characteristics of each IoT device. For example, ioT devices may be grouped into a home accessory group 1100, a home appliance/furniture group 1120, an entertainment device group 1140, or a vehicle group 1160. The plurality of IoT devices 1100, 1120, and 1140 may connect to a communication network or to other IoT devices through the AP 1200. AP 1200 may be embedded in one IoT device. Gateway 1250 may change protocols to connect AP 1200 to an external wireless network. IoT devices 1100, 1120, and 1140 may connect to external communication networks through gateway 1250. The wireless network 1300 may include the internet and/or a public network. IoT devices 1100, 1120, 1140, and 1160 may connect to server 1400 providing predefined services over wireless network 1300, and a user may use the services through at least one of IoT devices 1100, 1120, 1140, and 1160.

According to embodiments, ioT devices 1100, 1120, 1140, and 1160 may perform scheduling on a cell group including a plurality of cells corresponding to a plurality of frequency bands, and thus IoT devices 1100, 1120, 1140, and 1160 may identify scheduling for the cell group and perform communication based on the identification results.

The processes discussed above are intended to be illustrative and not limiting. Those of skill in the art will appreciate that the steps of the processes discussed herein may be omitted, modified, combined, and/or rearranged, and that any additional steps may be performed without departing from the scope of the invention. More generally, the above disclosure is intended to be illustrative and not limiting. Only the appended claims are intended to set forth the metes and bounds of the invention. Furthermore, it is to be noted that features and limitations described in any one embodiment may be applied to any other embodiment herein, and that flowcharts or examples relating to one embodiment may be combined with any other embodiment in a suitable manner, done in a different order, or done in parallel. Furthermore, the systems and methods described herein may be performed in real time. It should also be noted that the above-described systems and/or methods may be applied to or used in accordance with other systems and/or methods.

Claims (20)

1. A method of wireless communication, the method comprising:

receiving a Physical Downlink Control Channel (PDCCH) from a Base Station (BS), wherein the PDCCH corresponds to a cell group comprising a plurality of cells, and wherein the PDCCH is received through a specific cell in the cell group;

acquiring Downlink Control Information (DCI) from the PDCCH;

identifying, based on the DCI, whether scheduling has been performed on the cell group; and

a Physical Downlink Shared Channel (PDSCH) is received from the Base Station (BS) based on the DCI, wherein the PDSCH corresponds to the set of cells and is received by the plurality of cells.

2. The method of claim 1, further comprising:

higher layer signaling for scheduling settings for a User Equipment (UE) and the cell group is performed.

3. The method of claim 2, wherein the scheduling settings for the cell group comprise settings for a plurality of cell groups, wherein the plurality of cell groups comprises the cell group and cells included in each of the plurality of cell groups.

4. The method of claim 2, wherein performing the higher layer signaling comprises: performance information of the UE associated with scheduling for the cell group is sent to the BS.

5. The method of claim 4, wherein the performance information includes at least one of cells that the UE can support, the number of cells that can support, and a method of selecting the particular cell.

6. The method of claim 1, wherein identifying whether scheduling has been performed on the cell group further comprises:

the cell group is identified based on a cell group indicator field included in the DCI.

7. The method of claim 6, wherein identifying the group of cells comprises: the cell group is identified based on the value of the code of the cell group indicator field.

8. The method of claim 6, wherein identifying the group of cells comprises: the plurality of cells is identified based on a value of a bitmap of the cell group indicator field.

9. The method of claim 6, wherein identifying the group of cells comprises:

the cell group is identified based on some bits of the cell group indicator field and the plurality of cells are identified based on remaining bits of the cell group indicator field.

10. The method of claim 1, wherein identifying whether scheduling has been performed on the cell group comprises: based on information on resources allocated for transmitting the PDCCH included in the DCI, it is identified whether scheduling has been performed on the cell group.

11. The method of claim 1, wherein identifying whether scheduling has been performed on the cell group comprises: whether scheduling has been performed on the cell group is identified based on the format of the DCI.

12. The method of claim 1, wherein identifying whether scheduling has been performed on the cell group comprises: whether scheduling has been performed on the cell group is identified based on a Radio Network Temporary Identifier (RNTI) used when blind decoding for the PDCCH is successful.

13. The method of claim 1, further comprising:

the PDCCH candidates are determined taking into account the scheduling for the cell group.

14. The method of claim 1, wherein the DCI includes a carrier index having a value corresponding to any one of the plurality of cells.

15. The method of claim 1, wherein receiving PDSCH corresponding to the cell group by the plurality of cells comprises: determining a size of a frequency domain resource allocation field included in the DCI based on a cell having a largest bandwidth part or matching a largest frequency band among the plurality of cells.

16. A method of a Base Station (BS), the method comprising:

Performing higher layer signaling for scheduling settings for User Equipment (UE) and cell groups;

based on the higher layer signaling, generating Downlink Control Information (DCI) including information indicating at least one of: the cell group and a plurality of cells included in the cell group;

selecting any one of the plurality of cells based on the higher layer signaling;

scheduling a Physical Downlink Control Channel (PDCCH) including the DCI and corresponding to the cell group based on the selected cell; and

and sending the scheduled PDCCH to the UE.

17. The method of claim 16, wherein performing the higher layer signaling comprises: receiving performance information of the UE associated with scheduling for the cell group from the UE, and

the step of generating the DCI includes: the set of cells including the plurality of cells that match the performance information is selected.

18. The method of claim 17, wherein performing the higher layer signaling comprises: receiving performance information of the UE associated with scheduling for the cell group from the UE, and

the step of selecting any one of the plurality of cells comprises: one of the plurality of cells is selected based on a cell selection method corresponding to the performance information.

19. The method of claim 17, wherein the number of the plurality of cells is at least two.

20. A method of wireless communication, the method comprising:

receiving a Physical Downlink Control Channel (PDCCH) from a Base Station (BS) using a first cell in a cell group;

obtaining Downlink Control Information (DCI) from the PDCCH, wherein the DCI includes scheduling information for the first and second cells of the cell group; and

a Physical Downlink Shared Channel (PDSCH) is received from the Base Station (BS) based on the DCI using the first cell and the second cell.