Method and apparatus for transmitting and receiving channels using a guard band in a carrier in a wireless communication system

Abstract

A method for receiving a downlink channel by a terminal in a wireless communication system includes: receiving from a base station the first information relating to a guard band in a first resource region located in a carrier; receiving from the base station the second information relating to a plurality of resource sets, each of the plurality of resource sets being identified by the guard band in the first resource region based on the first information; and receiving the downlink channel from the base station on resources indicated by the second information as available for reception of the downlink channel.

Description

Technical Field

[0001] This specification relates to wireless communication systems, and more particularly, to methods and apparatus for transmitting or receiving channels using a guard band in a carrier wave. Background Technology

[0002] Following the commercialization of fourth-generation (4G) communication systems, efforts are underway to develop new fifth-generation (5G) communication systems to meet the increasing demand for wireless data services. 5G communication systems are also referred to as post-4G network communication systems, post-LTE systems, or new radio (NR) systems. To achieve high data transmission rates, 5G communication systems include systems operating in 6 GHz or higher millimeter-wave (mmWave) frequency bands, and systems operating in 6 GHz or lower frequency bands are also being considered to ensure coverage. The implementation methods in base stations and terminals are being considered.

[0003] The 3GPP (3rd Generation Partnership Project) NR system improves network spectral efficiency and enables communication providers to offer more data and voice services within a given bandwidth. Therefore, the 3GPP NR system is designed to meet the demand for high-speed data and media transmission in addition to supporting a large volume of voice calls. The advantages of the NR system include higher throughput and lower latency on the same platform, support for both Frequency Division Duplex (FDD) and Time Division Duplex (TDD), and low operating costs due to the enhanced end-user environment and simple architecture.

[0004] For more efficient data processing, the dynamic TDD of the NR system can use a method to change the number of Orthogonal Frequency Division Multiplexing (OFDM) symbols that can be used in the uplink and downlink based on the data traffic direction of cell users. For example, when the downlink traffic of a cell is greater than the uplink traffic, the base station can allocate multiple downlink OFDM symbols to a time slot (or subframe). Information about the time slot configuration should be sent to the terminal.

[0005] To mitigate path loss and increase transmission distance in the mmWave band, beamforming, massive MIMO, full-dimensional MIMO (FD-MIMO), array antennas, analog beamforming, hybrid beamforming combining analog and digital beamforming, and massive MIMO technologies are discussed in 5G communication systems. Furthermore, for network improvements, technologies related to evolved small cells, advanced small cells, cloud radio access networks (cloud RAN), ultra-dense networks, device-to-device (D2D) communication, vehicle-to-everything (V2X) communication, wireless backhaul, non-terrestrial network communication (NTN), mobile networks, cooperative communication, coordinated multipoint (CoMP), and interference cancellation are being developed in 5G communication systems. Additionally, hybrid FSK and QAM modulation (FQAM) and sliding window superposition coding (SWSC) are being developed as advanced coding and modulation (ACM) schemes, while filter bank multicarrier (FBMC), non-orthogonal multiple access (NOMA), and sparse code multiple access (SCMA) are being developed as advanced connectivity technologies.

[0006] Simultaneously, within the human-centric network of interconnected networks where humans generate and consume information, the Internet has evolved into the Internet of Things (IoT) network, which exchanges information between distributed components such as objects. The Internet of Everything (IoE) technology, combining IoT with big data processing through connections to cloud servers, is also emerging. Realizing IoT requires technological elements such as sensing technology, wired / wireless communication and network infrastructure, service interface technology, and security technology. This has led to the recent research into technologies such as sensor networks, machine-to-machine (M2M), and machine-type communication (MTC) to connect objects. In the IoT environment, intelligent Internet of Things (IT) services can be provided, collecting and analyzing data generated from connected objects to create new value in human life. Through the integration and hybridization of existing information technology (IT) with various industries, IoT can be applied to areas such as smart homes, smart buildings, smart cities, smart cars or connected cars, smart grids, healthcare, smart appliances, and advanced medical services.

[0007] Therefore, various attempts have been made to apply 5G communication systems to IoT networks. For example, technologies such as sensor networks, machine-to-machine (M2M), and machine-type communication (MTC) are implemented using techniques such as beamforming, MIMO, and array antennas. The application of cloud RAN as a big data processing technology is an example of the convergence of 5G and IoT technologies. Typically, mobile communication systems are developed to provide voice services while ensuring user activity.

[0008] However, mobile communication systems are not only expanding their voice services but also their data services, and have now evolved to the point of providing high-speed data services. However, due to resource shortages and users' demands for high-speed services, more advanced mobile communication systems are needed within the current mobile communication systems providing services.

[0009] In recent years, with the surge in mobile services due to the proliferation of smart devices, it has become increasingly difficult to cope with the increased data usage for providing cellular communication services using only existing licensed spectrum or licensed bands.

[0010] In this context, methods are being discussed for using unlicensed spectrum or unlicensed frequency bands (e.g., 2.4 GHz band, 5 GHz band, etc.) to provide cellular communication services in order to address the lack of spectrum.

[0011] Unlike licensed frequency bands, where telecommunications operators secure exclusive usage rights through auctions and other procedures, unlicensed frequency bands allow multiple communication devices to be used simultaneously without restriction, provided they comply with certain levels of adjacent frequency band protection regulations. Therefore, when unlicensed frequency bands are used for cellular communication services, it is difficult to guarantee the communication quality at the level provided in licensed frequency bands, and interference with existing wireless communication equipment (e.g., wireless LAN devices) using unlicensed frequency bands is highly likely.

[0012] To utilize LTE and NR technologies in unlicensed frequency bands, prior research will be conducted on coexistence with existing equipment used in unlicensed frequency bands and efficient sharing of wireless channels with other wireless communication devices. Specifically, robust coexistence mechanisms (RCMs) need to be developed to ensure that devices using LTE and NR technologies in unlicensed frequency bands do not affect existing equipment used in unlicensed frequency bands. Summary of the Invention

[0013] Technical issues

[0014] One aspect of this specification is to provide a method and apparatus for transmitting or receiving a channel in a wireless communication system using a guard band in a carrier wave.

[0015] Technical solution

[0016] This specification provides a method for receiving a downlink channel in a wireless communication system.

[0017] Specifically, a method performed by a terminal may include the following operations: receiving from a base station first information relating to a guard band in a first resource region located in a carrier; receiving from the base station second information relating to a plurality of resource sets, each of the plurality of resource sets being identified by a guard band in the first resource region based on the first information; and receiving a downlink channel from the base station on resources indicated by the second information as usable for reception of a downlink channel. The plurality of resource sets may be configured using resources other than those allocated to the guard band based on the first information. The second information may be information indicating whether each of the plurality of resource sets is usable for reception of a downlink channel.

[0018] Furthermore, in conjunction with this specification, the method performed by the terminal may further include the operation of receiving a Physical Downlink Control Channel (PDCCH) from a base station on a portion of a plurality of resource sets. Secondary information may be included in the downlink control information (DCI) of the PDCCH.

[0019] Furthermore, in conjunction with this specification, the method performed by the terminal may further include receiving information from the base station related to a second resource area monitored by the terminal for receiving the PDCCH.

[0020] A terminal for receiving a downlink channel in a wireless communication system may include: a transceiver; a processor; and a memory configured to store instructions for operations to be performed by the processor and connected to the processor. The operations may include: receiving from a base station first information relating to a guard band in a first resource region located in a carrier; receiving from the base station second information relating to a plurality of resource sets, each of the plurality of resource sets being identified by a guard band in the first resource region based on the first information; and receiving the downlink channel from the base station on resources indicated by the second information as available for reception of the downlink channel. The plurality of resource sets may be configured using resources other than those allocated to the guard band based on the first information. The second information may be information indicating whether each of the plurality of resource sets is available for reception of the downlink channel.

[0021] Additionally, the operation may further include receiving a Physical Downlink Control Channel (PDCCH) from a base station on a portion of a plurality of resource sets. Secondary information may be included in the downlink control information (DCI) of the PDCCH.

[0022] Additionally, the operation may further include receiving information from the base station related to a second resource area monitored by the terminal to receive the PDCCH.

[0023] Furthermore, in conjunction with this specification, a DCI can be a group-common DCI.

[0024] Furthermore, in conjunction with this specification, a second resource area may correspond to a portion of a plurality of resource sets, and the second resource area may include resources on which PDCCHs are received.

[0025] Furthermore, in conjunction with this specification, the second resource area may be the resource to which the control resource set (CORESET) is allocated.

[0026] Furthermore, in conjunction with this specification, the second information can be in the form of a bitmap type to indicate whether each of the multiple resource sets is available for transmission in the downlink channel.

[0027] Furthermore, in conjunction with this specification, the downlink channel can be at least one of the Physical Downlink Control Channel (PDCCH) and the Physical Downlink Shared Channel (PDSCH).

[0028] Furthermore, in conjunction with this specification, the first information and information related to the second resource area can be sent via higher-level signaling.

[0029] Furthermore, in conjunction with this specification, a method for transmitting a downlink channel by a base station in a wireless communication system may include the following operations: transmitting to a terminal first information relating to a guard band located in a first resource region within a carrier; transmitting to the terminal second information relating to a plurality of resource sets, each of the plurality of resource sets being identified by a guard band in the first resource region based on the first information; and transmitting the downlink channel to the terminal on resources indicated by the second information as usable for transmission of the downlink channel. The plurality of resource sets may be configured using resources other than those allocated to the guard band based on the first information. The second information may be information indicating whether each of the plurality of resource sets is usable for transmission of the downlink channel.

[0030] Furthermore, in conjunction with this specification, the second information can be in the form of a bitmap type to indicate whether each of the multiple resource sets is available for transmission in the downlink channel.

[0031] Beneficial effects

[0032] The advantage of this specification is that it enables efficient channel transmission by providing a method for configuring resources for uplink and downlink channel transmission when a guard band exists within a single carrier.

[0033] The beneficial effects available in this specification are not limited to those described above, and other beneficial effects not mentioned herein will be clearly understood by those skilled in the art to which this disclosure pertains based on the following description. Attached Figure Description

[0034] Figure 1 This diagram illustrates an example of a wireless frame structure used in a wireless communication system.

[0035] Figure 2 This diagram illustrates an example of a downlink (DL) / uplink (UL) timeslot structure in a wireless communication system.

[0036] Figure 3 This is a diagram used to illustrate the physical channels used in 3GPP systems and typical signal transmission methods using those physical channels.

[0037] Figure 4 The diagram illustrates the SS / PBCH block used for initial cell access in a 3GPP NR system.

[0038] Figure 5 The diagram illustrates a procedure for transmitting control information and control channels in a 3GPP NR system.

[0039] Figure 6 The diagram shows a control resource set (CORESET) in a 3GPP NR system that can transmit the Physical Downlink Control Channel (PUCCH).

[0040] Figure 7 The diagram illustrates a method for configuring the PDCCH search space in a 3GPP NR system.

[0041] Figure 8 This is a conceptual diagram illustrating carrier aggregation.

[0042] Figure 9 This diagram is used to illustrate signal carrier communication and multi-carrier communication.

[0043] Figure 10 This is a diagram illustrating an example of cross-carrier scheduling technology.

[0044] Figure 11 The illustration shows an example of a scenario where the terminal and base station are placed in an LAA service environment.

[0045] Figure 12 The illustration shows an example of a conventional communication scheme operating in an unlicensed frequency band.

[0046] Figure 13 and Figure 14 The illustration shows an example of the Listen-Before-Speak (LBT) process used for DL ​​transmission.

[0047] Figure 15 The illustration shows an example of DL transmission in an unlicensed frequency band.

[0048] Figure 16 The illustration shows an example of a method for adjusting the contention window size (CWS) when accessing a channel in an unlicensed frequency band.

[0049] Figure 17The illustration shows an example of a method for configuring a bandwidth portion (BWP) for a terminal in a 3GPP NR system, where the bandwidth is equal to or less than the bandwidth of the carrier (or cell).

[0050] Figure 18 The illustration shows an example where at least one core set of each BWP is configured or assigned to a terminal when multiple BWPs are assigned to the terminal.

[0051] Figure 19 This illustrates the operation of transmitting PDCCH in a CORESET configured in each basic bandwidth and transmitting PDSCH in a BWP when the base station configuration according to an embodiment of the present disclosure includes one or more basic bandwidths.

[0052] Figure 20 The diagram illustrates the operation in which, when the BWP is configured to include one or more basic bandwidths according to an embodiment of the present disclosure, the base station transmits PDCCH in a CORESET configured in each specified basic bandwidth and transmits PDSCH in the BWP according to its priority.

[0053] Figure 21 The illustration shows the operation of a base station transmitting one or more basic bandwidths when the BWP is configured to include one or more basic bandwidths according to an embodiment of the present disclosure, wherein one or more basic bandwidths for transmitting PDCCH are specified and the base station transmits PDCCH in a CORESET configured in each specified basic bandwidth and transmits PDSCH in the BWP according to the specified basic bandwidth.

[0054] Figure 22 This is a diagram illustrating the in-carrier guard band and carrier guard band in a BWP configured by one or more LBT subbands in a broadband carrier.

[0055] Figure 23 The illustration shows an example of the number of physical resource blocks (RBs) that can be used consecutively when using a BWP with a bandwidth of 20MHz, 40MHz, or 80MHz.

[0056] Figure 24 The illustration shows an embodiment of the number of physical resource RBs that can be continuously used as in-carrier guard bands when using a BWP with a bandwidth of 20MHz, 40MHz, or 80MHz, and an embodiment of the number of physical resource RBs that can be used for each LBT subband according to a BWP with a bandwidth of 20MHz, 40MHz, or 80MHz.

[0057] Figure 25 The illustration shows a block diagram of the configuration of a terminal and a base station according to embodiments of the present disclosure; and

[0058] Figure 26 This is a flowchart of a method for a terminal to receive a downlink channel according to an embodiment of the present disclosure. Detailed Implementation

[0059] The terminology used in this specification adopts, as far as possible, commonly used terms that are currently widely used, taking into account the functions of this invention. However, these terms may be modified according to the intent, habits, and emergence of new technologies of those skilled in the art. Furthermore, in certain cases, there are terms arbitrarily chosen by the applicant, and in such cases, their meaning will be described in the corresponding descriptive section of the invention. Therefore, it is intended to disclose that the terminology used in this specification should not be analyzed solely based on its name, but rather on its substantive meaning throughout the entire specification.

[0060] Throughout the specification and subsequent claims, when an element is described as being “connected” to another element, that element may be “directly connected” to the other element or “electrically connected” to the other element via a third element. Furthermore, unless explicitly stated otherwise, the word “comprising” will be understood to imply the inclusion of the stated element without implying the exclusion of any other elements. Additionally, in some exemplary embodiments, limitations such as “greater than or equal to” or “less than or equal to” based on a specific threshold may be appropriately replaced with “greater than” or “less than”, respectively.

[0061] The following technologies can be used in various wireless 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), and Single Carrier-FDMA (SC-FDMA). CDMA can be implemented using wireless technologies such as Universal Terrestrial Radio Access (UTRA) or CDMA2000. TDMA can be implemented using wireless technologies such as Global System for Mobile Communications (GSM), General Packet Radio Service (GPRS), and Enhanced Data Rate GSM Evolution (EDGE). OFDMA can be implemented using wireless technologies such as IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802-20, and Evolved UTRA (E-UTRA). UTRA is part of the Universal Mobile Telecommunications System (UMTS). The 3rd Generation Partnership Project (3GPP) Long Term Evolution (LTE) is part of Evolved UMTS (E-UMTS) using Evolved UMTS Terrestrial Radio Access (E-UTRA), and LTE Advanced (A) is an evolved version of 3GPP LTE. 3GPP New Radio (NR) is a system designed separately from LTE / LTE-A and is intended to support Enhanced Mobile Broadband (eMBB), Ultra-Reliable Low Latency Communication (URLLC), and Massive Machine-Type Communication (mMTC) services as required by IMT-2020. For clarity, 3GPP NR is described primarily, but the technical concept of this invention is not limited thereto.

[0062] Unless otherwise stated herein, a base station may include a next-generation node B (gNB) as defined in 3GPP NR. Furthermore, unless otherwise stated, a terminal may include a user equipment (UE). In the following description, each embodiment is described separately to aid understanding; however, each embodiment may be used in combination with each other. In this specification, the configuration of the UE may be indicated by the configuration of the base station. More specifically, the base station may configure the values ​​of parameters used in the operation of the UE or the wireless communication system by transmitting channels or signals to the UE.

[0063] Figure 1 This diagram illustrates an example of a wireless frame structure used in a wireless communication system.

[0064] refer to Figure 1 The radio frames (or radio frames) used in 3GPP NR systems can have a duration of 10ms (Δf). max N f / 100)*T c The length of the radio frame is Δf. Furthermore, a radio frame consists of 10 equal-sized subframes (SF). Here, Δf... max =480*10 3 Hz, Nf =4096, T c =1 / (Δf) ref *N f,ref ), Δf ref =15*10 3 Hz, and N f,ref =2048. Numbers from 0 to 9 can be assigned to 10 subframes within a single radio frame. Each subframe is 1ms long and can include one or more time slots depending on the subcarrier spacing. More specifically, in 3GPP NR systems, the usable subcarrier spacing is 15*2. μ The subcarrier spacing can be configured as μ = 0, 1, 2, 3, or 4. That is, 15 kHz, 30 kHz, 60 kHz, 120 kHz, and 240 kHz can be used for the subcarrier spacing. A subframe with a length of 1 ms can include 2... μ There are 2 time slots. In this case, the length of each time slot is 2. -μ ms. This can range from 0 to 2. μ The number -1 is assigned to 2 within a subframe. μ Each time slot. Furthermore, slots from 0 to 10*2 can be allocated. μ The number -1 is assigned to a time slot within a radio frame. Time resources can be distinguished by at least one of the radio frame number (also known as the radio frame index), subframe number (also known as the subframe index), and time slot number (or time slot index).

[0065] Figure 2 This diagram illustrates an example of a downlink (DL) / uplink (UL) timeslot structure in a wireless communication system. Specifically, Figure 2 The diagram illustrates the structure of the resource grid in a 3GPP NR system.

[0066] Each online port has a resource grid. (See reference) Figure 2 A time slot comprises multiple Orthogonal Frequency Division Multiplexing (OFDM) symbols in the time domain and multiple Resource Blocks (RBs) in the frequency domain. An OFDM symbol also refers to a symbol interval. Unless otherwise specified, an OFDM symbol may be simply referred to as a symbol. An RB comprises 12 consecutive subcarriers in the frequency domain. (See reference...) Figure 2 The signal transmitted from each time slot can be composed of N size,μ grid,x *N RB sc Subcarriers and N slot symb The resource grid of OFDM symbols is used for representation. Here, x = DL when the signal is a DL signal, and x = UL when the signal is a UL signal. N size,μ grid,xThis represents the number of resource blocks (RBs) based on the subcarrier spacing component μ (x is either DL or UL), and N slot symb Indicates the number of OFDM symbols in the time slot. N RB sc It is the number of subcarriers that make up an RB and N RB sc =12. OFDM symbols can be referred to as cyclic shift OFDM (CP-OFDM) symbols or discrete Fourier transform extended OFDM (DFT-s-OFDM) symbols according to the multiple access scheme.

[0067] The number of OFDM symbols included in a time slot can vary depending on the length of the cyclic prefix (CP). For example, with normal CP, a time slot includes 14 OFDM symbols, but with extended CP, a time slot can include 12 OFDM symbols. In certain embodiments, extended CP can only be used with a 60 kHz subcarrier spacing. Figure 2 For ease of description, as an example, a time slot is configured with 14 OFDM symbols; however, embodiments of this disclosure can be applied in a similar manner to time slots with different numbers of OFDM symbols. References Figure 2 Each OFDM symbol includes N in the frequency domain. size,μ grid,x *N RB sc Subcarriers can be categorized into data subcarriers for data transmission, reference signal subcarriers for reference signal transmission, and guard bands. The carrier frequency is also known as the center frequency (fc).

[0068] An RB can be composed of N in the frequency domain RB sc (For example, 12) consecutive subcarriers are defined. For reference, a resource configured with one OFDM symbol and one subcarrier can be called a resource element (RE) or tone. Therefore, an RB can be configured with N slot symb *N RB sc Each resource element in the resource grid can be uniquely defined by a pair of indices (k, l) in a time slot. k can be from 0 to N in the frequency domain. size,μ grid,x *N RB sc -1 is the index assigned, and l can be from 0 to N in the time domain. slot symb -1 is the index assigned.

[0069] To enable the UE to receive or transmit signals from the base station, the UE's time / frequency can be synchronized with the base station's time / frequency. This is because when the base station and the UE are synchronized, the UE can determine the necessary time and frequency parameters to demodulate the DL signal and transmit the UL signal at the correct time.

[0070] Each symbol of a radio frame used in Time Division Duplex (TDD) or unpaired spectrum can be configured with at least one of DL symbol, UL symbol, and flexible symbol. Radio frames used as DL carriers in Frequency Division Duplex (FDD) or paired spectrum can be configured with either DL symbol or flexible symbol, while radio frames used as UL carriers can be configured with either UL symbol or flexible symbol. In DL symbols, DL transmission is possible, but UL transmission is not. In UL symbols, UL transmission is possible, but DL transmission is not. A flexible symbol can be determined as being used as either DL or UL based on the signal.

[0071] Information regarding the type of each symbol—that is, information indicating any one of DL symbols, UL symbols, and flexible symbols—can be configured using cell-specific or public Radio Resource Control (RRC) signals. Furthermore, information regarding the type of each symbol can be additionally configured using UE-specific or dedicated RRC signals. The base station uses cell-specific RRC signals to inform i) the period of the cell-specific time slot configuration, ii) the number of time slots containing only DL symbols from the beginning of the cell-specific time slot configuration period, iii) the number of DL symbols starting from the first symbol of the time slot immediately following a time slot containing only DL symbols, iv) the number of time slots containing only UL symbols from the end of the cell-specific time slot configuration period, and v) the number of UL symbols starting from the last symbol of the time slot immediately preceding a time slot containing only UL symbols. Here, a symbol not configured with either UL or DL ​​symbols is a flexible symbol.

[0072] When information about symbol type is configured using UE-specific RRC signals, the base station can use cell-specific RRC signals to signal whether a flexible symbol is a DL symbol or a UL symbol. In this case, the UE-specific RRC signals cannot change a DL symbol or UL symbol configured using cell-specific RRC signals to another symbol type. The UE-specific RRC signals can signal the corresponding N of each time slot. slot symb The number of DL symbols in each symbol and the corresponding time slot N slot symbThe number of UL symbols among the symbols. In this case, the DL symbols of the time slot can be continuously configured with the first symbol to the i-th symbol of the time slot. In addition, the UL symbols of the time slot can be continuously configured with the j-th symbol to the last symbol of the time slot (where i < j). In a time slot, a symbol that is not configured with any of the UL symbols and DL symbols is a flexible symbol.

[0073] The type of symbol configured with the above RRC signal can be referred to as a semi-static DL / UL configuration. In the previously configured semi-static DL / UL configuration with the RRC signal, a flexible symbol can be indicated as a DL symbol, a UL symbol, or a flexible symbol through dynamic time slot format information (SFI) sent on the physical DL control channel (PDCCH). In this case, a DL symbol or a UL symbol configured with the RRC signal is not changed to another symbol type. Table 1 illustrates the dynamic SFI that a base station can indicate to a UE.

[0074] [Table 1]

[0075]

[0076] In Table 1, D represents a DL symbol, U represents a UL symbol, and X represents a flexible symbol. As shown in Table 1, up to two DL / UL switches in one time slot can be allowed.

[0077] Figure 3 It is a diagram for explaining physical channels used in a 3GPP system (e.g., NR) and a typical signal transmission method using the physical channel.

[0078] If the power of the UE is turned on or the UE camps on a new cell, the UE performs initial cell search (S101). Specifically, the UE can synchronize with the BS during the initial cell search. To this end, the UE can receive a primary synchronization signal (PSS) and a secondary synchronization signal (SSS) from the base station to synchronize with the base station and obtain information such as a cell index. Thereafter, the UE is able to receive a physical broadcast channel from the base station and obtain broadcast information in the cell.

[0079] After the initial cell search is completed, the UE receives a physical downlink shared channel (PDSCH) according to the physical downlink control channel (PDCCH) and the information in the PDCCH, so that the UE can obtain more specific system information than the system information obtained through the initial cell search (S102). Here, the system information received by the UE is cell common system information for the normal operation of the UE in the physical layer in radio resource control (RRC), and is referred to as remaining system information or system information block (SIB) 1.

[0080] When a UE initially accesses a base station or lacks radio resources for signal transmission (i.e., the UE is in RRC_idle mode), the UE can perform a random access procedure (operations S103 to S106) to the base station. First, the UE can send a preamble via the Physical Random Access Channel (PRACH) (S103) and receive a response message for the preamble from the base station via the PDCCH and the corresponding PDSCH (S104). When the UE receives a valid random access response message, the UE sends data, including the UE's identifier, to the base station via the Physical Uplink Shared Channel (PUSCH) indicated by the UL grant sent from the base station via the PDCCH (S105). Next, the UE waits for the reception of the PDCCH as an indication from the base station for conflict resolution. If the UE successfully receives the PDCCH via its identifier (S106), the random access procedure is terminated. During the random access procedure, the UE can obtain UE-specific system information for normal operation in the physical layer of the RRC layer. When the UE obtains the UE-specific system information, the UE enters RRC connected mode (RRC_connected mode).

[0081] The RRC layer is used to generate or manage messages that control the connection between the UE and the Radio Access Network (RAN). More specifically, within the RRC layer, the base station and UE can perform tasks such as broadcasting cell system information required by each UE in the cell, managing mobility and handover, UE measurement reports, and storage management including UE capability management and device management. Typically, because the update cycle of signals transmitted in the RRC layer is longer than the Transmission Time Interval (TTI) in the physical layer, RRC signals remain unchanged and are maintained for considerable intervals.

[0082] Following the above procedures, the UE receives the PDCCH / PDSCH (S107) and transmits the Physical Uplink Shared Channel (PUSCH) / Physical Uplink Control Channel (PUCCH) (S108) as a general UL / DL signal transmission procedure. Specifically, the UE can receive downlink control information (DCI) via the PDCCH. The DCI may include control information for the UE, such as resource allocation information. Furthermore, the format of the DCI can vary depending on the intended purpose. The uplink control information (UCI) transmitted by the UE to the base station via the UL includes DL / UL ACK / NACK signals, Channel Quality Indicator (CQI), Precoding Matrix Index (PMI), Rank Indicator (RI), etc. Here, CQI, PMI, and RI can be included in the Channel State Information (CSI). In 3GPP NR systems, the UE can transmit control information such as the aforementioned HARQ-ACK and CSI via the PUSCH and / or PUCCH.

[0083] Figure 4The diagram illustrates the SS / PBCH block used for initial cell access in a 3GPP NR system.

[0084] When power is on or when the UE wants to connect to a new cell, it can obtain time and frequency synchronization with that cell and perform an initial cell search procedure. The UE can detect the physical cell identifier N of the cell during the cell search procedure. cell ID Therefore, the UE can receive synchronization signals from the base station, such as the primary synchronization signal (PSS) and secondary synchronization signal (SSS), and synchronize with the base station. In this case, the UE can obtain information such as the cell identifier (ID).

[0085] refer to Figure 4 Section (a) describes the synchronization signal (SS) in more detail. Synchronization signals can be classified into PSS and SSS. PSS can be used to obtain time-domain synchronization and / or frequency-domain synchronization, such as OFDM symbol synchronization and slot synchronization. SSS can be used to obtain frame synchronization and cell group ID. (See reference...) Figure 4 According to (a) and Table 2, the SS / PBCH block can be configured with 20 consecutive RBs (=240 subcarriers) on the frequency axis and 4 consecutive OFDM symbols on the time axis. In this case, in the SS / PBCH block, the PSS is transmitted in the first OFDM symbol via subcarriers 56 to 182, and the SSS is transmitted in the third OFDM symbol. Here, the lowest subcarrier index of the SS / PBCH block is numbered starting from 0. In the first OFDM symbol for transmitting the PSS, the base station does not transmit signals via the remaining subcarriers, i.e., subcarriers 0 to 55 and subcarriers 183 to 239. Furthermore, in the third OFDM symbol for transmitting the SSS, the base station does not transmit signals via subcarriers 48 to 55 and subcarriers 183 to 191. The base station transmits the Physical Broadcast Channel (PBCH) via the remaining REs in the SS / PBCH block, excluding the signals mentioned above.

[0086] [Table 2]

[0087]

[0088] The SS allows a total of 1008 unique physical layer cell IDs to be divided into 336 physical layer cell identifier groups through a combination of three PSSs and SSSs. Each group includes three unique identifiers, specifically ensuring that each physical layer cell ID is only a part of one physical layer cell identifier group. Therefore, the physical layer cell ID N cell ID =3N (1) ID +N (2) IDAn index N, ranging from 0 to 335, can be used to indicate the physical layer cell identifier group. (1) ID and an index N indicating the range of physical layer identifiers in the physical layer cell identifier group from 0 to 2. (2) ID Uniquely defined. The UE can detect the PSS and identify one of three unique physical layer identifiers. Furthermore, the UE can detect the SSS and identify one of 336 physical layer cell IDs associated with the physical layer identifier. In this case, the sequence d of the PSS... PSS (n) is as follows.

[0089] d PSS (n) = 1 - 2x(m)

[0090]

[0091] 0≤n<127

[0092] Here, x(i+7) = (x(i+4) + x(i)) mod 2 and is given as

[0093] [x(6) x(5) x(4) x(3) x(2) x(1) x(0)]=[1 1 1 0 1 1 0]

[0094] In addition, the sequence d of SSS SSS (n) is as follows.

[0095] d SSS (n)=[1-2x0((n+m0)mod127)][-2x1((n+m l )mod127)]

[0096]

[0097] 0≤n<127

[0098] here, And it was given as,

[0099] [x0(6) x0(5) x0(4) x0(3) x0(2) x0(1) x0(0)]=[0 0 0 0 0 0 1]

[0100] [x1(6) x1(5) x1(4) x1(3) x1(2) x1(1) x1(0)]=[0 0 0 0 0 0 1]

[0101] A radio frame with a length of 10ms can be divided into two half-frames with a length of 5ms each. (Reference) Figure 4Section (b) describes the time slots for transmitting the SS / PBCH block in each half-frame. The time slot for transmitting the SS / PBCH block can be any of cases A, B, C, D, and E. In case A, the subcarrier spacing is 15 kHz and the start time of the SS / PBCH block is the ({2,8}+14*n)th symbol. In this case, at carrier frequencies of 3 GHz or lower, n = 0 or 1. Furthermore, at carrier frequencies above 3 GHz and below 6 GHz, n can be 0, 1, 2, or 3. In case B, the subcarrier spacing is 30 kHz and the start time of the SS / PBCH block is {4,8,16,20}+28*n. In this case, at carrier frequencies of 3 GHz or lower, n = 0. Furthermore, at carrier frequencies above 3 GHz and below 6 GHz, n can be 0 or 1. In case C, the subcarrier spacing is 30 kHz and the start time of the SS / PBCH block is the ({2,8}+14*n)th symbol. In this case, at carrier frequencies of 3 GHz or lower, n = 0 or 1. Furthermore, at carrier frequencies above 3 GHz but below 6 GHz, n can be 0, 1, 2, or 3. In case D, the subcarrier spacing is 120 kHz and the start time of the SS / PBCH block is the ({4,8,16,20}+28*n)th symbol. In this case, at carrier frequencies of 6 GHz or higher, n = 0, 1, 2, 3, 5, 6, 7, 8, 10, 11, 12, 13, 15, 16, 17, 18. In case E, the subcarrier spacing is 240 kHz and the start time of the SS / PBCH block is the ({8,12,16,20,32,36,40,44}+56*n)th symbol. In this case, at carrier frequencies of 6 GHz or higher, n = 0, 1, 2, 3, 5, 6, 7, 8.

[0102] Figure 5 The diagram illustrates the process of transmitting control information and using the control channel in a 3GPP NR system. (Reference) Figure 5In step (a), the base station can add a Cyclic Redundancy Check (CRC) masked with a Radio Network Temporary Identifier (RNTI) (e.g., XOR operation) to the control information (e.g., downlink control information (DCI)) (S202). The base station can scramble the CRC with an RNTI value determined according to the purpose / objective of each control information. The common RNTI used by one or more UEs can include at least one of System Information RNTI (SI-RNTI), Paging RNTI (P-RNTI), Random Access RNTI (RA-RNTI), and Transmit Power Control RNTI (TPC-RNTI). In addition, UE-specific RNTIs can include at least one of Cell Temporary RNTI (C-RNTI) and CS-RNTI. Thereafter, the base station can perform rate matching according to the amount of resources used for PDCCH transmission after performing channel coding (e.g., polarity coding) (S204) (S206). Thereafter, the base station can multiplex the DCI based on the PDCCH structure based on Control Channel Elements (CCE) (S208). Furthermore, the base station can apply additional processes such as scrambling, modulation (e.g., QPSK), interleaving, etc., to the multiplexed DCI (S210), and then map the DCI to the resources to be transmitted. CCE is the basic resource unit used for PDCCH, and a CCE can include multiple (e.g., six) resource element groups (REGs). A REG can be configured with multiple (e.g., 12) REs. The number of CCEs used for a PDCCH can be defined as the aggregation level. In 3GPPNR systems, aggregation levels of 1, 2, 4, 8, or 16 can be used. Figure 5 (b) is a diagram relating to CCE aggregation levels and PDCCH multiplexing, and illustrates the type of CCE aggregation level used for a PDCCH and the CCEs sent in the control area accordingly.

[0103] Figure 6 The diagram shows a control resource set (CORESET) in a 3GPP NR system that can transmit the Physical Downlink Control Channel (PUCCH).

[0104] A CORESET is a time-frequency resource in which PDCCH (i.e., control signals for the UE) is transmitted. Furthermore, a search space, described later, can be mapped to a CORESET. Therefore, the UE can monitor the time-frequency domain designated as a CORESET instead of all frequency bands used for PDCCH reception, and decode the PDCCH mapped to the CORESET. The base station can configure one or more CORESETs for each cell for the UE. A CORESET can be configured with up to three consecutive symbols on the time axis. Additionally, a CORESET can be configured in units of six consecutive PRBs on the frequency axis. Figure 5 In this embodiment, CORESET#1 is configured with consecutive PRBs, while CORESET#2 and CORESET#3 are configured with discontinuous PRBs. A CORESET can reside in any symbol within a time slot. For example, in... Figure 5 In one embodiment, CORESET#1 begins at the first symbol of the time slot, CORESET#2 begins at the fifth symbol of the time slot, and CORESET#9 begins at the ninth symbol of the time slot.

[0105] Figure 7 The diagram illustrates a method for setting up the PUCCH search space in a 3GPP NR system.

[0106] To transmit PDCCH to a UE, each CORESET may have at least one search space. In embodiments of this disclosure, the search space is the set of all time-frequency resources (hereinafter referred to as PDCCH candidates) capable of being used to transmit a UE's PDCCH. The search space may include a common search space that requires UEs of 3GPP NR to search together and a terminal-specific search space or UE-specific search space that requires a specific UE to search. In the common search space, a UE may monitor a PDCCH that is configured to be searched together by all UEs belonging to the same base station cell. Furthermore, a UE-specific search space may be set for each UE, such that the UE monitors the PDCCH allocated to each UE at search space locations that differ depending on the UE. In the case of a UE-specific search space, the search spaces between UEs may partially overlap and be allocated due to the limited control area that can be allocated PDCCH. Monitoring the PDCCH includes blind decoding of PDCCH candidates in the search space. When blind decoding is successful, it can be expressed as (successfully) detecting / receiving the PDCCH, and when blind decoding fails, it can be expressed as not detecting / receiving or not successfully detecting / receiving the PDCCH.

[0107] For ease of explanation, a PDCCH scrambled with a Group Common (GC) RNTI previously known to one or more UEs to transmit DL control information to one or more UEs is called a Group Common (GC) PDCCH or a common PDCCH. Furthermore, a PDCCH scrambled with a RNTI of a specific terminal already known to a specific UE to transmit UL scheduling information or DL ​​scheduling information to that specific UE is called a UE-specific PDCCH. Common PDCCHs can be included in the common search space, and UE-specific PDCCHs can be included in either the common search space or the UE-specific PDCCH.

[0108] The base station can signal to each UE or group of UEs via the PDSCH information regarding resource allocation for the Paging Channel (PCH) and Downlink Shared Channel (DL-SCH) as transport channels (i.e., DL clearance) or resource allocation for the Uplink Shared Channel (UL-SCH) and Hybrid Automatic Repeat Request (HARQ) (i.e., UL clearance). The base station can transmit PCH transport blocks and DL-SCH transport blocks via the PDSCH. The base station can also transmit data excluding specific control information or specific service data via the PDSCH. Furthermore, the UE can receive data excluding specific control information or specific service data via the PDSCH.

[0109] The base station can include information in the PDCCH about which UE (one or more UEs) the PDSCH data is sent to and how the PDSCH data will be received and decoded by the corresponding UE, and then send the PDCCH. For example, suppose the DCI sent on a particular PDCCH is CRC masked with RNTI "A", and the DCI indicates that the PDSCH is allocated to radio resource "B" (e.g., frequency location) and indicates transmission format information "C" (e.g., transport block size, modulation scheme, coding information, etc.). The UE uses the RNTI information it possesses to monitor the PDCCH. In this case, if there is a UE performing blind decoding of the PDCCH using RNTI "A", then that UE receives the PDCCH and, based on the information in the received PDCCH, receives the PDSCH indicated by "B" and "C".

[0110] Table 3 illustrates an example of the Physical Uplink Control Channel (PUCCH) used in a wireless communication system.

[0111] [Table 3]

[0112] PUCCH format Length of OFDM symbol Number of bits 0 1-2 ≤2 1 4-14 ≤2 2 1-2 ＞2 3 4-14 ＞2 4 4-14 ＞2

[0113] PUCCH can be used to send the following UL control information (UCI).

[0114] - Scheduling Request (SR): Information used to request UL UL-SCH resources.

[0115] -HARQ-ACK: A response to the PDCCH (indicating DL SPS release) and / or to a DL transport block (TB) on the PDSCH. HARQ-ACK indicates whether information successfully transmitted on the PDCCH or PDSCH has been received. HARQ-ACK responses include positive ACK (abbreviated as ACK), negative ACK (hereinafter NACK), discontinuous transmission (DTX), or NACK / DTX. Here, the terms HARQ-ACK are used interchangeably with HARQ-ACK / NACK and ACK / NACK. Typically, ACK can be represented by a bit value of 1, while NACK can be represented by a bit value of 0.

[0116] - Channel State Information (CSI): Feedback information about the DL channel. The UE generates it based on the CSI-reference signal (RS) transmitted by the base station. MIMO-related feedback information includes the Rank Indicator (RI) and the Precoding Matrix Indicator (PMI). The CSI can be divided into CSI Part 1 and CSI Part 2 based on the information indicated by the CSI.

[0117] In the 3GPP NR system, five PUCCH formats can be used to support various service scenarios, channel environments, and frame structures.

[0118] PUCCH format 0 is a format capable of delivering 1 or 2 bits of HARQ-ACK information or SR. PUCCH format 0 can be transmitted using one or two OFDM symbols on the time axis and one PRB on the frequency axis. When transmitting PUCCH format 0 over two OFDM symbols, the same sequence on both symbols can be transmitted using different RBs. In this case, the sequence can be a cyclically shifted (CS) sequence from the underlying sequence used in PUCCH format 0. Thus, the UE can obtain frequency diversity gain. More specifically, the UE can, according to M... bit Bit UCI (M) bit =1 or 2) to determine the cyclic shift (CS) value m cs Additionally, this can be achieved by using a predetermined CS value m. cs The cyclic shift sequence is mapped to an OFDM symbol and 12 REs of an RB to transmit a base sequence of length 12. When the number of cyclic shifts available to the UE is 12 and M... bit When M = 1, 1-bit UCI 0 and 1 can be mapped to two cyclic shift sequences, with the cyclic shift values ​​of these two sequences differing by 6. Additionally, when M... bitWhen =2, the 2-bit UCI 00, 01, 11 and 10 can be mapped to four cyclic shift sequences with a difference of 3 in the cyclic shift value.

[0119] PUCCH format 1 can deliver 1 or 2 bits of HARQ-ACK information or SR. PUCCH format 1 can be transmitted using consecutive OFDM symbols on the time axis and one PRB on the frequency axis. Here, the number of OFDM symbols occupied by PUCCH format 1 can be one of 4 to 14. More specifically, it can be used for M... bit BPSK modulation is performed using a UCI of 1. The UE can then use Quadrature Phase Shift Keying (QPSK) to modulate the M... bit Modulation is performed using a UCI of 2. The signal is obtained by multiplying the modulated complex-valued symbol d(0) by a sequence of length 12. In this case, the sequence can be the base sequence used for PUCCH format 0. The UE transmits the obtained signal by extending the even-numbered OFDM symbols assigned to PUCCH format 1 with a time-axis orthogonal cover code (OCC). PUCCH format 1 determines the maximum number of different UEs multiplexed in an RB based on the length of the OCC to be used. The demodulation reference signal (DMRS) can be extended with the OCC and mapped to the odd-numbered OFDM symbols of PUCCH format 1.

[0120] PUCCH format 2 can deliver more than 2 bits of UCI. PUCCH format 2 can be transmitted via one or two OFDM symbols on the time axis and one or more RBs on the frequency axis. When transmitting PUCCH format 2 in two OFDM symbols, the sequences transmitted in different RBs through the two OFDM symbols can be identical. Here, the sequence can be multiple modulated complex-valued symbols d(0), ..., d(M). symbol -1). Here, M symbol It can be M bit / 2. Through this, the UE can obtain frequency diversity gain. More specifically, for M... bit One bit UCI (M bit >2) Perform bit-level scrambling, QPSK modulation, and map it to one or two OFDM symbols' RBs. Here, the number of RBs can be one from 1 to 16.

[0121] PUCCH format 3 or PUCCH format 4 can deliver more than 2 bits of UCI. PUCCH format 3 or PUCCH format 4 can be transmitted via consecutive OFDM symbols on the time axis and one PRB on the frequency axis. The number of OFDM symbols occupied by PUCCH format 3 or PUCCH format 4 can be one of 4 to 14. Specifically, the UE utilizes π / 2-binary phase shift keying (BPSK) or QPSK to transmit M... bit One bit UCI (M bit >2) Modulate to generate complex numerical symbols d(0) to d(M) symb -1). Here, when using π / 2-BPSK, M symb =M bit However, when using QPSK, M symb =M bit / 2. The UE may not apply block unit extension to PUCCH format 3. However, the UE may use a 12-length PreDFT-OCC to apply block unit extension to one RB (i.e., 12 subcarriers), allowing PUCCH format 4 to have two or four multiplexing capabilities. The UE performs transmit precoding (or DFT precoding) on ​​the extended signal and maps it to each RE to transmit the extended signal.

[0122] In this scenario, the number of Restricted Blocks (RBs) occupied by PUCCH format 2, PUCCH format 3, or PUCCH format 4 can be determined based on the length of the UCI sent by the UE and the maximum coding rate. When the UE uses PUCCH format 2, it can send HARQ-ACK and CSI information together via PUCCH. When the number of RBs that the UE can send exceeds the maximum number of RBs that can be used with PUCCH format 2, PUCCH format 3, or PUCCH format 4, the UE can choose not to send some UCI information based on the priority of the UCI information, and instead only send the remaining UCI information.

[0123] PUCCH format 1, PUCCH format 3, or PUCCH format 4 can be configured using the RRC signal to indicate frequency hopping in the time slot. When frequency hopping is configured, the index of the RB to be hopped can be configured using the RRC signal. When PUCCH format 1, PUCCH format 3, or PUCCH format 4 is transmitted over N OFDM symbols on the time axis, the first transition can have floor (N / 2) OFDM symbols and the second transition can have ceiling (N / 2) OFDM symbols.

[0124] PUCCH format 1, PUCCH format 3, or PUCCH format 4 can be configured to be repeatedly transmitted in multiple time slots. In this case, the number K of time slots in which the PUCCH is repeatedly transmitted can be configured via an RRC signal. The repeatedly transmitted PUCCH must begin at a constant position in the OFDM symbol within each time slot and have a constant length. When one of the OFDM symbols in the time slot where the UE should transmit the PUCCH is indicated as a DL symbol via an RRC signal, the UE can choose not to transmit the PUCCH in the corresponding time slot and delay the transmission of the PUCCH to the next time slot.

[0125] In 3GPP NR systems, a UE can perform transmission / reception using a bandwidth equal to or less than the carrier (or cell) bandwidth. For this purpose, the UE can receive a bandwidth portion (BWP) of a continuous bandwidth configured with some bandwidth of the carrier bandwidth. A UE operating under TDD or in unpaired spectrum can receive up to four DL / UL BWP pairs on a single carrier (or cell). Additionally, a UE can activate one DL / UL BWP pair. A UE operating under FDD or in paired spectrum can receive up to four DL BWPs on a DL carrier (or cell) and up to four ULBWPs on a UL carrier (or cell). A UE can activate one DL BWP and one UL BWP for each carrier (or cell). The UE may not perform reception or transmission in time-frequency resources other than the activated BWP. The activated BWP can be referred to as the active BWP.

[0126] The base station can indicate the active BWP among those configured by the UE via downlink control information (DCI). The BWP indicated by the DCI is activated, and other configured BWPs are deactivated. In a TDD-operated carrier (or cell), the base station can include a bandwidth portion indicator (BPI) in the DCI used for scheduling PDSCH or PUSCH, which indicates the BWP to be activated to change the UE's DL / UL BWP pair. The UE can receive the DCI used for scheduling PDSCH or PUSCH and can identify the DL / UL BWP pair activated based on the BPI. For a DL carrier (or cell) operating in FDD, the base station can include a BPI in the DCI used for scheduling PDSCH indicating the BWP to be activated to change the UE's DL BWP. For a UL carrier (or cell) operating in FDD, the base station can include a BPI in the DCI used for scheduling PUSCH indicating the BWP to be activated to change the UE's UL BWP.

[0127] Figure 8 This is a conceptual diagram illustrating carrier aggregation.

[0128] Carrier aggregation is a method in which a UE uses multiple frequency blocks or (in a logical sense) cells configured with UL resources (or component carriers) and / or DL ​​resources (or component carriers) as a large logical band so that the wireless communication system can use a wider bandwidth. A component carrier can also be referred to by the terms primary cell (PCell), secondary cell (SCell), or primary SCell (PScell). However, for convenience, the term "component carrier" will be used below.

[0129] refer to Figure 8 As an example of a 3GPP NR system, the entire system bandwidth can include up to 16 component carriers, and each component carrier can have a bandwidth of up to 400 MHz. Component carriers can include one or more physically contiguous subcarriers. Although in Figure 8 The diagram illustrates that each component carrier has the same bandwidth, but this is merely an example, and each component carrier can have a different bandwidth. Furthermore, although each component carrier is illustrated as being adjacent to each other on the frequency axis, the diagram is illustrated conceptually, and each component carrier can be physically adjacent to each other or can be spaced apart.

[0130] Different center frequencies can be used for each component carrier. Alternatively, a common center frequency can be used for physically adjacent component carriers. Assuming in... Figure 8 In one embodiment, all component carriers are physically adjacent, so center frequency A can be used in all component carriers. Alternatively, assuming the component carriers are not physically adjacent to each other, then center frequency A and center frequency B can be used in each component carrier.

[0131] When extending the total system bandwidth through carrier aggregation, the bandwidth used for communication with each UE can be defined on a component carrier basis. UE A can use 100MHz as the total system bandwidth and perform communication using all five component carriers. UEs B1-B5 can perform communication using only 20MHz bandwidth and one component carrier. UEs C1 and C2 can each use 40MHz bandwidth and two component carriers for communication. These two component carriers can be logically / physically adjacent or non-adjacent. UE C1 represents the case of using two non-adjacent component carriers, while UE C2 represents the case of using two adjacent component carriers.

[0132] Figure 9 This is a diagram used to illustrate single-carrier communication and multi-carrier communication. Specifically, Figure 9 The diagram in (a) illustrates the single-carrier subframe structure and Figure 9 The diagram in (b) shows the multi-carrier subframe structure.

[0133] refer to Figure 9 In (a) of the above, in FDD mode, a typical wireless communication system can perform data transmission or reception using a DL band and a corresponding UL band. In another specific embodiment, in TDD mode, the wireless communication system can divide radio frames into UL time units and DL time units in the time domain, and perform data transmission or reception using the UL / DL time units. (See reference...) Figure 9 In (b), three 20MHz component carriers (CCs) can be aggregated into each of the UL and DL, enabling a bandwidth of 60MHz. Each CC can be adjacent to or not adjacent to each other in the frequency domain. Figure 9 Figure (b) illustrates a case where the bandwidth of the UL CC and DL CC are the same and symmetrical, but the bandwidth of each CC can be determined independently. Furthermore, asymmetric carrier aggregation with different numbers of UL CCs and DL CCs is possible. The DL / UL CCs allocated / configured to a specific UE via RRC can be referred to as the serving DL / UL CCs for that specific UE.

[0134] A base station can communicate with a UE by activating some or all of the UE's serving CCs or by deactivating some CCs. The base station can change the CCs to be activated / deactivated, and can change the number of CCs to be activated / deactivated. If the base station allocates CCs available to the UE as cell-specific or UE-specific, at least one of the allocated CCs will not be deactivated unless the CC allocation for the UE is completely reconfigured or the UE is handed over. A CC that is not deactivated by the UE is called the primary CC (PCC) or primary cell (PCell), while CCs that the base station can freely activate / deactivate are called secondary CCs (SCCs) or secondary cells (SCells).

[0135] Meanwhile, 3GPP NR uses the concept of cells to manage radio resources. A cell is defined as a combination of DL resources and UL resources, i.e., a combination of DL CC and UL CC. A cell can be configured with DL resources alone, or it can be configured with a combination of DL resources and UL resources. When carrier aggregation is supported, the link between the carrier frequencies of DL resources (or DL ​​CC) and UL resources (or UL CC) can be indicated by system information. The carrier frequency refers to the center frequency of each cell or CC. The cell corresponding to a PCC is called a PCell, and the cell corresponding to an SCC is called an SCell. The carrier corresponding to a PCell in DL is the DL PCC, and the carrier corresponding to a PCell in UL is the UL PCC. Similarly, the carrier corresponding to an SCell in DL is the DL SCC, and the carrier corresponding to an SCell in UL is the UL SCC. Depending on the UE's capabilities, a serving cell can be configured with one PCell and zero or more SCells. In the case of a UE in the RRC_CONNECTED state but not configured for carrier aggregation or not supporting carrier aggregation, only one serving cell is configured with only a PCell.

[0136] As mentioned above, the term "cell" used in carrier aggregation is distinguished from the term "cell" referring to a geographical area that provides communication services through a base station or an antenna array. That is, a component carrier can also be referred to as a scheduled cell, a scheduled cell, a primary cell (PCell), a secondary cell (SCell), or a primary SCell (PScell). However, to distinguish between cells representing a geographical area and cells in carrier aggregation, in this disclosure, cells in carrier aggregation are referred to as CCs, and cells representing a geographical area are referred to as cells.

[0137] Figure 10 This diagram illustrates an example of cross-carrier scheduling. When cross-carrier scheduling is set up, the control channel transmitted via the first CC can use the Carrier Indicator Field (CIF) to schedule the data channel transmitted via either the first CC or the second CC. The CIF is included in the DCI. In other words, a scheduling cell is set up, and the DL license / UL license transmitted in the PDCCH area of ​​that scheduling cell schedules the PDSCH / PUSCH of the scheduled cell. That is, there is a search area for multiple component carriers in the PDCCH area of ​​the scheduling cell. A PCell can essentially be a scheduling cell, and a specific SCell can be designated as a scheduling cell by a higher layer.

[0138] exist Figure 10In the embodiment, it is assumed that three DL CCs are combined. Here, it is assumed that DL component carrier #0 is a DLPCC (or PCell), and DL component carriers #1 and #2 are DL SCCs (or SCells). Furthermore, it is assumed that the DLPCC is configured as a PDCCH monitoring CC. When cross-carrier scheduling is not configured via UE-specific (or UE group-specific or cell-specific) higher-layer signaling, CIF is disabled, and each DL CC can transmit only the PDCCH for scheduling its PDSCH according to the NR PDCCH rules without CIF (non-cross-carrier scheduling, self-carrier scheduling). Meanwhile, if cross-carrier scheduling is configured via UE-specific (or UE group-specific or cell-specific) higher-layer signaling, CIF is enabled, and a specific CC (e.g., DL PCC) can use CIF to transmit not only the PDCCH for scheduling DL CC A but also the PDCCH for scheduling another CC (cross-carrier scheduling). On the other hand, no PDCCH is transmitted in another DL CC. Therefore, the UE monitors the PDCCH excluding CIF to receive the PDSCH scheduled by the carrier, or monitors the PDCCH including CIF to receive the PDSCH scheduled by the carrier, depending on whether cross-carrier scheduling is configured for the UE.

[0139] on the other hand, Figure 9 and Figure 10 The diagram illustrates the subframe structure of a 3GPP LTE-A system, and the same or similar configuration can be applied to a 3GPP NR system. However, in a 3GPP NR system, Figure 9 and Figure 10 Subframes can be replaced with time slots.

[0140] Furthermore, the NR system uses code block group (CBG) based transmission, which differs from 3GPP LTE(-A). The following description relates to this.

[0141] In 3GPP LTE(-A), a TB Cyclic Redundancy Code (TB-CRC) is appended to a TB for detecting errors in a Transport Block (TB). A TB is a unit of data transmitted in the PDSCH, and for channel coding efficiency, a TB is divided into several Code Blocks (CBs). A CB Cyclic Redundancy Code (CB-CRC) for detecting errors in a CB is appended to each CB. Upon receiving the PDSCH, if no error is detected in the TB-CRC, the terminal sends an ACK; if an error is detected in the TB-CRC, the terminal sends a NACK. That is, a HARQ-ACK is sent for each TB. When a NACK is received, the base station determines that an error has occurred in the previous TB and performs HARQ retransmission of all CBs in the TB. Therefore, in an LTE system, if only one CB is erroneously received, all CBs included in the TB are retransmitted. Thus, there is a possibility of inefficient retransmissions. To address this issue, the NR system employs the following approach: Binding CBs configured with TBs to form code block groups (CBGs), enabling HARQ-ACK transmission at the CBG level; in downlink transmission, notifying the base station whether each CBG was successfully received as CBG-level HARQ-ACK feedback; and having the base station perform HARQ retransmission only for CBGs that were not received. Similarly, in uplink transmission, the NR system can be configured as follows: in addition to configuring HARQ-ACK transmission at the TB level for uplink transmission, binding CBs configured with TBs for uplink transmission to form code block groups (CBGs), thus allowing HARQ-ACK transmission at the CBG level; notifying the terminal whether each CBG was successfully received as CBG-level HARQ-ACK feedback; and having the terminal perform HARQ retransmission only for CBGs that were not received.

[0142] Figure 11 The illustration shows an example of a scenario where a terminal and base station are placed in a Licensed Assisted Access (LAA) service environment. Due to its high-frequency characteristics, the frequency band targeted by the Licensed Assisted Access (LAA) service environment does not have a long wireless communication range. Considering this, in an environment where traditional LTE-L and LAA services coexist, the placement of the terminal and base station can be either a coverage model or a co-location model.

[0143] In the coverage model, the macro base station can perform wireless communication with terminals X and X' in macro area 32 using licensed frequency band carriers, and can connect to multiple Radio Remote Headers (RRHs) via the X2 interface. Each RRH can perform wireless communication with terminal X or terminal X' in predetermined area 31 using unlicensed frequency band carriers. The macro base station and RRHs have different frequency bands, therefore there is no interference between them, but fast data exchange between the macro base station and RRHs is required via the X2 interface to use LAA service as an auxiliary downlink channel for LTE-L service via carrier aggregation.

[0144] In the co-location model, a pico / femto base station can perform wireless communication with terminal Y by simultaneously using both licensed and unlicensed frequency band carriers. However, a pico / femto base station can use both LTE-L and LAA services only when performing downlink transmissions. The coverage area 33 of LTE-L service and the coverage area 34 of LAA service can vary depending on frequency band, transmission power, etc.

[0145] When LTE communication is performed in unlicensed frequency bands, existing devices communicating in unlicensed frequency bands (e.g., Wi-Fi wireless LAN devices) cannot demodulate LAA messages or data. Therefore, existing devices can determine that the LAA message or data is an energy level and then perform interference avoidance operations using energy detection techniques. That is, if the energy corresponding to the LAA message or data is less than -62 dBm or a specific energy detection (ED) threshold, the wireless LAN device can communicate while ignoring the message or data. Therefore, terminals performing LTE communication in unlicensed frequency bands may be frequently interfered with by wireless LAN devices.

[0146] Therefore, to effectively implement LAA technology / services, specific frequency bands need to be allocated or reserved during specific time intervals. However, peripheral devices communicating via unlicensed frequency bands attempt to access the network based on energy detection technology, making it difficult to effectively provide LAA services. Therefore, to install LAA technology, it is necessary to research methods for coexistence with existing unlicensed frequency band devices and methods for effectively sharing wireless channels. That is, a strong coexistence mechanism for LAA devices that does not affect existing unlicensed frequency band devices needs to be developed.

[0147] Figure 12 The illustration shows an example of a conventional communication scheme (e.g., a wireless LAN) operating in an unlicensed frequency band. Devices operating in unlicensed frequency bands mostly operate based on Listen-Before-Speak (LBT) and therefore perform Clear Channel Assessment (CCA) of the sensing channel before transmitting data.

[0148] Reference Figure 12Before transmitting data, a wireless LAN device (e.g., an AP or STA) performs carrier sensing to check if the channel is in use (busy). When a wireless signal of a predetermined strength or higher is sensed in the channel on which data is to be transmitted, the wireless LAN device determines that the channel is busy and delays access to the channel. This process is called idle channel assessment, and the signal level used to determine whether a signal is sensed is called the CCA threshold. Conversely, when no wireless signal is sensed in the channel, or a wireless signal with a strength less than the CCA threshold is sensed, the device determines that the channel is idle.

[0149] When a terminal determines that the channel is idle, it performs a backoff procedure after a delay period (e.g., Arbitrated Inter-Frame Interval (AIFS), PCF IFS (PCIFS), etc.). The delay period is the minimum time interval the terminal must wait after the channel has become idle. The backoff procedure allows the terminal to wait longer for a predetermined time interval after the delay period. For example, when the channel is idle, the terminal can wait while reducing the slot time interval to the random number assigned to it in the Contention Window (CW), and after all slot times have elapsed, the terminal can attempt to access the channel.

[0150] When a terminal successfully accesses the channel, it can transmit data through the channel. When data transmission is successful, the Channel Warp Size (CWS) is reset to its initial value (CWmin). Conversely, when data transmission fails, the CWS doubles. Therefore, the terminal receives a new random number assigned within twice the previous random number range and then performs a fallback procedure in the next CW. In a wireless LAN, only an ACK is defined as a received response message for data transmission. Therefore, when an ACK for data transmission is received, the CWS is reset to its initial value, and when no feedback message for data transmission is received, the CWS doubles.

[0151] As mentioned above, traditional communication in unlicensed frequency bands mostly operates based on LBT (Local Broadband Access), therefore LTE also considers LBT in LAA (Local Broadband Access Area) to coexist with existing devices. Specifically, based on the presence or absence of LBT, or the LBT application scheme, the methods for accessing channels in unlicensed frequency bands in LTE can be divided into the following four categories.

[0152] Category 1: No LBT

[0153] -Tx entities do not perform the LBT procedure for transmission.

[0154] Category 2: LBT lacking random backoff

[0155] The Tx entity senses whether the channel is idle during the first interval without random backoff in order to perform a transmission. That is, the Tx entity can perform a transmission through the channel immediately after sensing that the channel is idle during the first interval. The first interval is an interval of a pre-configured length immediately preceding the Tx entity's transmission. According to an embodiment, the first interval may have a length of 25 μs, but this disclosure is not limited thereto.

[0156] Category 3: LBT with random backoff performed using a fixed-size CW

[0157] The Tx entity obtains a random number N from a CW of fixed size and configures N as a backoff counter (or backoff timer), and performs backoff using the configured backoff counter N. That is, during the backoff process, whenever the channel is sensed to be idle during a pre-configured time slot interval, the Tx entity decrements the backoff counter by 1. The pre-configured time slot interval can be 9 μs, but this disclosure is not limited to this. The backoff counter decreases from its initial value N, and when the backoff counter reaches 0, the Tx entity can perform transmission. Simultaneously, to perform backoff, the Tx entity first senses whether the channel is idle during a second interval. The second interval can be configured based on the Tx entity's channel access priority level and includes a 16 μs time interval and m consecutive time slot intervals. m is a value configured according to the channel access priority level. When it is determined that the channel is idle during the second interval, the Tx entity performs channel sensing to decrement the backoff counter. Simultaneously, when the channel is sensed to be occupied during the backoff process, the backoff process is stopped. After the backoff process is stopped, the Tx entity can restart the backoff process when the channel is sensed to be idle during the second interval. As described above, if the channel is idle during the time slot interval of the N-fold backoff counter, in addition to the second interval, the Tx entity can perform the transmission. The N-fold backoff counter is obtained within a fixed-size CW.

[0158] Category 4: LBT with random backoff performed using a variable-size CW

[0159] The Tx entity obtains a random number N in a CW of variable size and configures N as a backoff counter (or backoff timer), and performs backoff using the configured backoff counter N. More specifically, the Tx entity can adjust the size of the CW based on previously transmitted HARQ-ACK information and obtain a backoff counter N in a CW of adjusted size. The detailed process of the Tx entity performing backoff is the same as described in Category 3. The Tx entity can perform transmission when the channel is idle during the slot interval of the backoff counter N, except for the second interval. A backoff counter of N is obtained in the variable-size CW.

[0160] The Tx entities described in categories 1 to 4 can be base stations or terminals. According to embodiments of this disclosure, a first type of channel access can indicate channel access of category 4, and a second type of channel access can indicate channel access of category 2.

[0161] Figure 13 and Figure 14 The diagram illustrates an example of a DL transmission process based on Category 4 LBT. Category 4 LBT can be used to ensure fair channel access compared to Wi-Fi. (Reference) Figure 13 and Figure 14 The LBT process includes an Initial CCA (ICCA) and an Extended CCA (ECCA). In ICCA, random backoff is not performed, while in ECCA, random backoff is performed using a CW with a variable size. ICCA is applied when the channel is idle at the point in time when signal transmission is needed, while ECCA is applied when the channel is busy at the point in time when signal transmission is needed, or when there is a DL transmission immediately preceding that point in time. That is, ICCA determines whether the channel is idle, and data transmission is performed after the ICCA period. If interference is identified, and therefore data transmission is impossible, a random backoff counter can be configured, and the data transmission time can then be obtained by delaying the period and using the backoff counter.

[0162] Reference Figure 13 The signal transmission process can be performed as follows.

[0163] Initial CCA

[0164] -S302: The base station has identified that the channel is in an idle state.

[0165] -S304: The base station checks whether signal transmission is required. When signal transmission is not required, the base station returns to operation S302; when signal transmission is required, operation S306 is performed.

[0166] -S306: The base station checks whether the channel is idle during the ICCA delay period (BCCA). The ICCA delay period is configurable. In an embodiment, the ICCA delay period can be configured with a 16μs interval and n consecutive CCA slots. Here, n can be a positive integer, and a CCA slot interval can be 9μs. The number of CCA slots can be configured differently depending on the QoS category. By taking into account the delay period of Wi-Fi (e.g., DIFS or AIFS), the ICCA delay period can be configured to an appropriate value. For example, the ICCA delay period can be 34μs. If the channel is idle during the ICCA delay period, the base station can perform the signal transmission procedure (S308). If it is determined that the channel is busy during the ICCA delay period, operation S312 (ECCA) is performed.

[0167] -S308: The base station can perform a signal transmission procedure. If there is no signal transmission, operation S302 (ICCA) is performed; if there is signal transmission, operation S310 is performed. Even if the backoff counter of N reaches 0 in operation S318, and therefore operation S308 is performed, if there is no signal transmission, operation S302 (ICCA) is performed, and if there is signal transmission, operation S310 is performed.

[0168] -S310: When no additional signal transmission is required, perform operation S302 (ICCA); when additional signal transmission is required, perform operation S312 (ECCA).

[0169] Extended CCA

[0170] -S312: The base station generates a random number N in the CW. N is used as a counter during the back-off process and is generated from [0, q-1]. The CW is configured with q ECCA time slots, and the size of each ECCA time slot can be 9μs or 10μs. The CW size (CWS) is defined as q and can be variable in operation S314. After this, the base station continues with operation S316.

[0171] -S314: The base station can update the CWS. The CWS q can be updated to a value between X and Y. The X and Y values ​​are configurable parameters. CWS updates or adjustments can be performed each time N is generated (dynamic backoff), or they can be performed semi-statically at predetermined time intervals (semi-static backoff). The CWS can be updated or adjusted based on exponential backoff or binary backoff. That is, the CWS can be updated or adjusted to the square of 2 or a multiple of 2. Regarding PDSCH transmission, the CWS can be updated or adjusted based on terminal feedback / reports (e.g., HARQ-ACK / NACK), or it can be updated or adjusted based on base station sensing.

[0172] -S316: The base station checks whether the channel is idle during the ECCA delay period (DeCCA). The ECCA delay period is configurable. In an embodiment, the ECCA delay period can be configured with a 16μs interval and n consecutive CCA slots. n can be a positive integer, and a CCA slot interval can be 9μs. The number of CCA slots can be configured differently depending on the QoS category. The ECCA delay period can be configured to an appropriate value by taking into account the delay period of Wi-Fi (e.g., DIFS or AIFS). For example, the ECCA delay period can be 34μs. If the channel is idle during the ECCA delay period, the base station continues operating S318. If it is determined that the channel is busy during the ECCA delay period, the base station repeats operating S316.

[0173] -S318: The base station checks if N is 0. When N is 0, the base station can execute the signal transmission process (S308). In this case (i.e., N = 0), the base station does not immediately execute the transmission and performs a CCA check during at least one time slot to continue the ECCA process. When N is not equal to 0 (i.e., N > 0), operation S320 is performed.

[0174] -S320: The base station senses the channel during one ECCA time slot interval (T). The ECCA time slot size is 9μs or 10μs, and the actual sensing time interval can be at least 4μs.

[0175] -S322: When it is determined that the channel is idle, proceed with operation S324. When it is determined that the channel is busy, the base station returns to operation S316. That is, an ECCA delay period is applied again after the channel is idle, and N is not counted down during the ECCA delay period.

[0176] -S324: The base station decrements N by 1 (ECCA countdown).

[0177] Figure 14 The transmission process shown is similar to Figure 13 The transmission processes are basically the same or similar, but there are differences between them depending on the type of implementation. Therefore, for details, please refer to... Figure 13 The given description.

[0178] Initial CCA

[0179] -S402: The base station checks whether signal transmission is required. If signal transmission is not required, repeat operation S402; if signal transmission is required, perform operation S404.

[0180] -S404: The base station identifies that the time slot is idle. When the time slot is idle, operation S406 is performed; when the time slot is busy, operation S412 (ECCA) is performed. This time slot can correspond to... Figure 13 The CCA time slot is shown in the figure.

[0181] -S406: The base station checks whether the channel is idle during the delay period (D). D can correspond to... Figure 13 The ICCA delay period is shown in the diagram. If the channel is idle during the delay period, the base station can perform a signal transmission procedure (S408). If it is determined that the channel is busy during the delay period, operation S404 is performed.

[0182] -S408: If a signal transmission process is required, the base station can perform the process.

[0183] -S410: If no signal is transmitted, operation S402 (ICCA) is performed, and if a signal is transmitted, operation S412 (ECCA) is performed. Even if the backoff counter of N reaches 0 in operation S418 and therefore operation S408 is performed, if no signal is transmitted, operation S402 (ICCA) is performed, and if a signal is transmitted, operation S412 (ECCA) is performed.

[0184] Extended CCA

[0185] -S412: The base station generates a random number N in the CW. N is used as a counter during the backoff process and is generated from [0, q-1]. The CW size (CWS) is defined as q and can be variable in operation S414. After this, the base station continues with operation S416.

[0186] -S414: The base station can update the CWS. The CWS q can be updated to a value between X and Y. The X and Y values ​​are configurable parameters. CWS updates or adjustments can be performed each time N is generated (dynamic backoff), or they can be performed semi-statically at predetermined time intervals (semi-static backoff). The CWS can be updated or adjusted based on exponential backoff or binary backoff. That is, the CWS can be updated or adjusted to the square of 2 or a multiple of 2. Regarding PDSCH transmission, the CWS can be updated or adjusted based on terminal feedback / reports (e.g., HARQ-ACK / NACK), or it can be updated or adjusted based on base station sensing.

[0187] -S416: The base station checks whether the channel is idle during the delay period (D). D can correspond to... Figure 13 The ECCA delay period is shown in Figure 406. In operations S406 and S416, the value of D can be the same. If the channel is idle during the delay period, the base station continues with operation S418. If it is determined that the channel is busy during the delay period, the base station repeats operation S416.

[0188] -S418: The base station checks if N is 0. When N is 0, the base station can execute the signal transmission procedure (S408). In this case (N=0), the base station does not immediately execute the transmission, and performs a CCA check during at least one time slot to continue the ECCA procedure. When N is not equal to 0 (i.e., N>0), operation S420 is performed.

[0189] -S420: The base station can choose either to decrement N by 1 (ECCA countdown) or not to decrement N (self-delay). The self-delay operation can be performed by the base station according to the implementation method or selection. During self-delay, the base station neither performs sensing for energy detection nor performs ECCA countdown.

[0190] -S422: The base station can choose to either not perform the sensing operation for energy detection or perform one of the energy detection operations. If the base station does not perform the sensing operation for energy detection, operation S424 is performed. In the case of performing the energy detection operation, operation S424 is performed when the energy level is equal to or lower than the energy detection threshold (i.e., idle). When the energy level exceeds the energy detection threshold (i.e., busy), the base station returns to operation S416. That is, a delay period is applied again after the channel is in an idle state, and N is not counted down during the delay period.

[0191] -S424: Perform operation S418.

[0192] Figure 15 The diagram illustrates an example of a base station performing DL transmission in an unlicensed frequency band. A base station can aggregate one or more licensed frequency band cells (for convenience, these can be referred to as LTE-L cells or NR licensed cells) and one or more unlicensed frequency band cells (for convenience, these can be referred to as LTE-U cells, NR unlicensed cells, or NR-U cells). Figure 15 In this example, we assume an LTE-L cell and an LTE-U cell are aggregated for communication with a terminal. The LTE-L cell can be a PCell, and the LTE-U cell can be an SCell. In the LTE-L cell, the base station can exclusively use frequency resources and perform legacy operations according to LTE. Therefore, radio frames can be configured by each regular subframe (rSF) with a length of 1ms (see [reference]). Figure 2 ), and DL transmissions (e.g., PDCCH or PDSCH) can be performed on a per-subframe basis (see [link]). Figure 1 In LTE-U cells, DL transmission is performed based on LBT (Low-Band Burst) for coexistence with existing devices (e.g., Wi-Fi devices). Furthermore, to effectively implement LTE-U technology / services, specific frequency bands need to be allocated or reserved during specific time intervals. Therefore, in LTE-U cells, DL transmission can be performed over a set of one or more consecutive subframes following an LBT (DL Burst). Depending on the LBT configuration, the DL Burst can be performed as follows: Figure 15 It begins with a regular subframe (rSF) as shown in (a) in the image, or it can begin with, as shown in the image. Figure 15 The partial subframe (pSF) shown in (b) begins. The pSF is a part of the subframe and may include a second time slot of the subframe. Furthermore, a DL transmission burst may end with either an rSF or a pSF.

[0193] The following describes a method for adaptively adjusting Channel Window (CWS) in an unlicensed frequency band during channel access. The CWS can be adjusted based on User Equipment (UE) feedback, and the UE feedback used for CWS adjustment can include HARQ-ACK responses and CQI / PMI / RI. This disclosure presents a method for adaptively adjusting the CWS based on HARQ-ACK responses. HARQ-ACK responses include ACK, NACK, and DTX.

[0194] For reference Figure 12 As shown, CWS in Wi-Fi is also adjusted based on ACK. If an ACK is received, CWS is reset to its minimum value (CWmin), and if no ACK is received, CWS increases. However, in cellular systems (such as LTE), a CWS adjustment method for multiple access points needs to be considered.

[0195] First, the terms are defined as follows for the description of this disclosure.

[0196] - HARQ-ACK Feedback Value Set (HARQ-ACK Feedback Set): This refers to the HARQ-ACK feedback values ​​used for CWS updates / adjustments. The HARQ-ACK feedback set corresponds to HARQ-ACK feedback values ​​that have been decoded and are available at the time point in determining the CWS. The HARQ-ACK feedback set includes HARQ-ACK feedback values ​​for one or more DL (channel) transmissions (e.g., PDSCH) on unlicensed frequency bands (e.g., LTE-U cells). The HARQ-ACK feedback set can include HARQ-ACK feedback values ​​for DL ​​(channel) transmissions (e.g., PDSCH), such as multiple HARQ-ACK feedback values ​​fed back from multiple terminals. HARQ-ACK feedback values ​​indicate receive response information for transport blocks or PDSCH and can indicate ACK, NACK, DTX, and NACK / DTX. Depending on the context, HARQ-ACK feedback values ​​can be used with HARQ-ACK values / bits / responses / information.

[0197] - Reference window: This refers to the time interval during which a DL transmission (e.g., PDSCH) corresponding to the HARQ-ACK feedback set is performed in an unlicensed frequency band (e.g., LTE-U cell). The reference window can be defined in units of fractional units (SF). The reference window will be described and presented in more detail later.

[0198] In LTE, the HARQ-ACK feedback value can indicate only ACK or NACK, or further indicate DTX depending on the HARQ-ACK feedback scheme, PUCCH format, etc. For example, if PUCCH format 3 is configured using the HARQ-ACK feedback method, the HARQ-ACK value can indicate only ACK and NACK. Meanwhile, when using a channel selection scheme with PUCCH format 1b configured by the HARQ-ACK feedback method, the HARQ-ACK value can indicate ACK, NACK, DTX, or NACK / DTX.

[0199] Reference Figure 16 After the base station transmits the nth DL transmission burst in an unlicensed frequency band (e.g., an LTE-U cell) (S502), if additional DL transmission is required, the base station can transmit the (n+1)th DL transmission burst based on ECCA (S512). Specifically, when the channel in the unlicensed frequency band is empty during the ECCA delay period, the base station additionally performs backoff in the CW (S510). The base station can generate a random number N in the CW (e.g., [0, q-1]) (S508) and perform backoff for the same number of time slots as the random number N (S510). In this disclosure, the CWS can be adjusted based on the HARQ-ACK feedback value from the terminal (S506). The HARQ-ACK feedback value used for CWS adjustment includes the HARQ-ACK feedback value associated with the latest DL transmission burst (the nth DL transmission burst). The HARQ-ACK feedback value used for CWS adjustment includes the HARQ-ACK feedback value associated with the DL transmission on the reference window in the DL transmission burst (S504).

[0200] In the above description of this disclosure to date, LTE-based LAA cells have been defined as LTE-U cells; however, the same applies to NR. NR licensed cells can be replaced with LTE-L cells, and NR unlicensed cells can also be replaced with LTE-U cells, as applied in this disclosure. However, for any points that differ from the use of NR unlicensed cells, if there is a relevant reference in the details of this disclosure, that reference applies to NR unlicensed cells.

[0201] <BWP operations for wideband operation in NR system>

[0202] Figure 17 The illustration shows an example of a method for configuring a BWP (Band of Power) for a terminal in a 3GPP NR system with a bandwidth equal to or less than the bandwidth of the carrier (or cell).

[0203] Reference Figure 17In 3GPP NR systems, terminals can use bandwidth equal to or less than the carrier (or cell) bandwidth to perform transmission or reception. For this purpose, the terminal can receive configurations for multiple Base Station Warranty (BWPs) from the base station. Each BWP is configured by consecutive Base Station Block (PRBs). (See reference...) Figure 17 In (a), BWPs can be separated into non-overlapping units. One or more of these non-overlapping BWPs can be assigned and configured for a terminal. The terminal can perform transmission or reception with the base station by using the assigned and configured BWPs. (See also...) Figure 17 In (b), BWPs can be separated while overlapping within the carrier bandwidth. One BWP can be configured to be included in another BWP. One or more BWPs that are separated while overlapping can be assigned and configured for the terminal. The terminal can perform transmission or reception with the base station by using one of the assigned and configured BWPs.

[0204] Figure 18 The illustration shows an example of a method for configuring or assigning a CORESET in a BWP assigned to a terminal.

[0205] Reference Figure 18 When multiple BWPs are assigned to a terminal, at least one CORESET can be configured or assigned to each BWP. (See reference...) Figure 18 (a) and Figure In (b) of this document, whether BWPs are configured to not overlap or to overlap, the CORESET for each BWP can be located within the time / frequency resource area occupied by each BWP. In other words, CORESET #1 for bandwidth portion #1 can exist within the PRB of the time / frequency resource area occupied by bandwidth portion #1, and CORESET #2 for bandwidth portion #2 can exist within the PRB of the time / frequency resource area occupied by bandwidth portion #2. (See reference...) ​ In (b), when bandwidth portions are configured to overlap, a PRB occupied by a CORESET can be located in another bandwidth portion, even if the PRB is still within the time / frequency resource area of ​​that CORESET's bandwidth portion. In other words, CORESET #2 for bandwidth portion #2 can overlap with the PRB in the time / frequency resource area occupied by bandwidth portion #1.

[0206] In a Time Division Duplex (TDD) cell, up to four downlink BWPs (DL BWPs) and up to four uplink BWPs (UL BWPs) can be configured per cell. For a terminal, one DL BWP and one ULBWP can be activated simultaneously in a cell. In a Frequency Division Duplex (FDD) cell, up to four DL / UL BWP pairs can be configured per cell. For a terminal, one DL / UL BWP can be activated simultaneously in a cell. The terminal does not expect to receive any signals in the PRB other than the activated DL BWP, and does not expect to transmit any signals in the PRB other than the activated UL BWP. When a terminal moves from one BWP to another, the base station instructs the terminal to deactivate the currently used BWP and activate a new BWP using downlink control information (DCI). More specifically, the DCI scheduling PDSCH includes a Bandwidth Part Indicator (BPI) indicating the BWP to be activated, in order to change the terminal's DL BWP in the TDD cell. That is, if a DCI scheduling PDSCH is received, the terminal can identify the BWP that will transmit PDSCH through it via the BPI. Furthermore, the terminal can identify the PRB of the BWP that will transmit PDSCH through it via the Resource Allocation (RA) information of the DCI. Similarly, the DCI for scheduling PUSCH includes a Bandwidth Part Indicator (BPI) indicating the BWP to be activated to change the UL BWP of the terminal in a TDD cell. That is, if a DCI for scheduling PUSCH is received, the terminal can identify the BWP that will transmit PUSCH through it via the BPI. Additionally, the terminal can identify the PRB of the indicated BWP that will transmit PUSCH through it via the RA information of the DCI. In an FDD cell, the BWP values ​​of the DCIs for scheduling PDSCH and PUSCH can indicate one of the DL / UL BWP pairs.

[0207] A wireless communication device operating in a wireless communication system according to embodiments of this disclosure can perform an LBT process in a pre-specified bandwidth to perform the LBT process in an unlicensed frequency band. The pre-specified bandwidth may be referred to as the LBT bandwidth, LBT subband, or LBT base bandwidth. For ease of explanation, in the following description, the pre-specified bandwidth is referred to as the base bandwidth. Specifically, when accessing a channel, the wireless communication device can determine whether the channel is idle in units of the base bandwidth. In a detailed embodiment, the wireless communication device can determine whether the channel is idle in units of the pre-specified base bandwidth and determine whether to perform a transmission in the channel based on the determination of whether the channel is idle. Furthermore, the base bandwidth can be 20 MHz. The 20 MHz size can be determined considering coexistence with another wireless communication device using an unlicensed frequency band (e.g., a wireless LAN device). In this specification, the wireless communication device may be referred to as a terminal or a base station. Additionally, the wireless communication device may be referred to as both a terminal and a base station. Therefore, both channel access for UL transmission and channel access for DL ​​transmission can be performed in units of the base bandwidth. As described above, when a wireless communication device performs channel access in an unlicensed frequency band in units of basic bandwidth, the method of performing channel access by using a bandwidth greater than the basic bandwidth, or by performing channel access with a BWP having a bandwidth greater than the basic bandwidth, can be problematic. As mentioned above, a BWP corresponds to a consecutive set of PRBs selected from a consecutive subset of RBs for a given carrier and a given set of parameters. A base station can configure one or more DL BWPs for the terminal for downlink, and can perform transmission to the terminal through one of the one or more configured DL BWPs active downlink DLBWPs. Furthermore, a base station can configure one or more UL BWPs for the terminal for uplink, and can schedule resources for uplink transmission to the terminal through one of the one or more configured UL BWPs active uplink UL BWPs. Specifically, the method for accessing a channel by a wireless communication device can be problematic when a frequency resource corresponding to one basic bandwidth is idle but another resource corresponding to the basic bandwidth is in use (busy). This is because, in a BWP, if the wireless communication device cannot transmit data in the BWP when a frequency resource corresponding to one basic bandwidth is idle while another resource corresponding to the basic bandwidth is busy, frequency efficiency (spectral efficiency) may decrease.

[0208] In a detailed embodiment, the base station can assign the bandwidth of the BWP to a basic bandwidth. In this case, the base station can perform downlink transmissions simultaneously in multiple BWPs. The terminal can perform uplink transmissions simultaneously in multiple BWPs. In these embodiments, the specific operations of the base station and the terminal can be the same as the channel access operations in multicarriers defined in 3GPP TS 36.213v14.8.0. In another detailed embodiment, the base station can configure the bandwidth of the BWP to an integer multiple of the basic bandwidth. A detailed method for accessing a channel by a wireless communication device using a BWP in a wireless communication system operating in an unlicensed frequency band will be described.

[0209] A base station can configure multiple Bandwidth Parts (BWPs) for a terminal in unlicensed frequency bands. Specifically, the base station can configure multiple downlink BWPs for the terminal in unlicensed frequency bands. The base station can activate multiple BWPs for the terminal in unlicensed frequency bands. In this embodiment, the operation methods of the base station and the terminal will be described first. The base station can indicate information about the activated BWPs to the terminal by sending Bandwidth Parts (BWP) related signaling. The terminal can receive BWP related signaling from the base station and can determine the BWPs activated for the terminal. Specifically, the base station can configure one or more activated downlink BWPs for the terminal among multiple downlink BWPs through dedicated RRC signaling. Alternatively, as described above, the base station can indicate the activated BWPs among the BWPs configured for the terminal through DCI. The terminal can receive the DCI and determine the activated BWPs based on the DCI.

[0210] When a base station successfully accesses a channel in one or more BWPs, it can transmit PDSCH in those BWPs where channel access has been successful. That is, if multiple BWPs exist where the base station has successfully accessed a channel, the base station can transmit PDSCH in those multiple BWPs. The base station can transmit a PDCCH (Planning Data Center Communication) to schedule the PDSCH in the BWP that is sending the PDSCH, and each PDCCH can include scheduling information for the PDSCH transmitted in the BWP that sent the corresponding PDCCH. The PDSCH scheduling information indicates information about the time and frequency resources used for PDSCH transmission. When multiple BWPs are active among those configured for a terminal, the terminal may not determine which BWP will successfully access the channel from among the multiple active BWPs. Therefore, the terminal can monitor the PDCCH in the CORESET configured in each of the multiple active BWPs to attempt to receive the PDCCH. The terminal can receive the PDSCH in each BWP by using the PDSCH scheduling information included in the received PDCCH. The terminal can monitor the PDCCH in all BWPs configured for the terminal. Specifically, the terminal can monitor the PDCCH in the CORESET of all BWPs configured for the terminal. Additionally, the terminal can receive the PDSCH in the corresponding BWP based on the PDSCH scheduling information included in the received PDCCH. In this embodiment, the terminal needs to monitor the PDCCH in all BWPs configured for the terminal, which may increase the complexity of blind decoding of the PDCCH. Furthermore, it may also increase the power consumed by the terminal in receiving the PDCCH. In this specification, successful channel access can indicate the permission for transmission in the corresponding channel according to the channel access procedure. The channel access procedure can indicate the LBT procedure described above.

[0211] The base station can configure different Base Window (BWP) with different frequency resources. Furthermore, the base station can configure different BWPs with overlapping frequency resources. For example, if different BWPs are configured to overlap, a portion of the frequency resources of the first BWP and a portion of the frequency resources of the second BWP can be the same. Additionally, the frequency resources of the second BWP can be included in the frequency resources of the first BWP. For ease of explanation, if the frequency resources of different BWPs overlap, the BWP is referred to as an overlapping BWP. The base station configures a CoreSet for each BWP, and the terminal monitors the PDCCH in the CoreSet resources of each BWP. If overlapping BWPs exist, the terminal can sequentially monitor the PDCCH in the overlapping BWPs according to their priority. In this embodiment, when the terminal receives the PDCCH in one BWP, the terminal may not monitor the PDCCH in a BWP with a lower priority than the BWP in which the PDCCH is received. Priorities can be configured based on the bandwidth size of the BWP. In a detailed embodiment, a BWP with a wider bandwidth can have a higher priority. When the bandwidth of the first BWP is greater than the bandwidth of the second BWP, the terminal can monitor the PDCCH in the first BWP and then in the second BWP. In another detailed embodiment, a BWP with narrower bandwidth can have higher priority. When the bandwidth of the first BWP is less than that of the second BWP, the terminal can monitor the PDCCH in the first BWP and then in the second BWP. This operation can be efficient when the base station can only perform transmissions in a BWP if it successfully accesses the channel across all the basic bandwidths included in the BWP. This is because, if the base station can only perform transmissions in a BWP if it successfully accesses the channel across all the basic bandwidths included in the BWP, the terminal is likely to send the PDCCH in a BWP with narrower bandwidth.

[0212] In another embodiment, even when the base station successfully accesses the channel in multiple BWPs, it can still transmit a PDSCH in one of the BWPs that have successfully accessed the channel. The base station can determine the BWP that will transmit the PDSCH based on priority among the multiple BWPs that have successfully accessed the channel. The base station can transmit a PDCCH that schedules the PDSCH in the BWP that will transmit the PDSCH. The terminal can determine the sequence of multiple BWPs to monitor the PDCCH based on the priority of the multiple BWPs. If multiple BWPs are activated for the terminal, the terminal can monitor the PDCCH sequentially in the multiple BWPs according to their priority. When the terminal receives a PDCCH in one BWP, it can omit PDCCH monitoring in BWPs other than the BWP that received the PDCCH. Specifically, when the terminal receives a PDCCH that schedules the PDSCH in one BWP, it can omit monitoring the PDCCH that schedules the PDSCH in BWPs other than the BWP that received the PDCCH.

[0213] Priority can be determined based on the index of the BWP. In a detailed embodiment, a BWP with a larger index can have a higher priority. For example, if the base station has successfully accessed the channel in both the first and second BWPs, and the index of the first BWP is greater than the index of the second BWP, the base station can determine the first BWP as the BWP to transmit PDSCH in both the first and second BWPs. The terminal can monitor the PDCCH in the first BWP and then monitor the PDCCH in the second BWP. In another detailed embodiment, a BWP with a smaller index can have a higher priority. For example, if the base station has successfully accessed the channel in both the first and second BWPs, and the index of the first BWP is less than the index of the second BWP, the base station can determine the first BWP as the BWP to transmit PDSCH in both the first and second BWPs. The terminal can monitor the PDCCH in the first BWP and then monitor the PDCCH in the second BWP. When the terminal receives the PDCCH in a high-priority BWP associated with monitoring the PDCCH, the terminal can omit PDCCH monitoring in BWPs other than the BWP that receives the PDCCH. Specifically, when a terminal receives a PDCCH that schedules a PDCCH in a high-priority BWP associated with monitoring the PDCCH, it can omit monitoring the PDCCH that schedules the PDCCH in BWPs other than the BWP that receives the PDCCH.

[0214] In another detailed embodiment, priority can be determined based on the bandwidth of the BWP. Specifically, a BWP with narrower bandwidth can have higher priority. For example, if the base station has successfully accessed the channel in both the first and second BWPs, and the bandwidth of the first BWP is less than that of the second BWP, the base station can determine the first BWP as the BWP to transmit PDSCH in both the first and second BWPs. The terminal can monitor the PDCCH in the first BWP and then in the second BWP. In another detailed embodiment, a BWP with wider bandwidth can have higher priority. For example, if the base station has successfully accessed the channel in both the first and second BWPs, and the bandwidth of the first BWP is greater than that of the second BWP, the base station can determine the first BWP as the BWP to transmit PDSCH in both the first and second BWPs. The terminal can monitor the PDCCH in the first BWP and then in the second BWP. Furthermore, in the above embodiments, if multiple BWPs have the same bandwidth, priority can be determined based on the BWP index.

[0215] In another detailed embodiment, the base station can configure one or more BWPs for the terminal in an unlicensed frequency band, and can be limited to activating only one of the configured BWPs. Therefore, even if multiple BWPs are configured for the terminal in an unlicensed frequency band, the base station can activate only one BWP for the terminal in the unlicensed frequency band. In this embodiment, the operation methods of the base station and the terminal will be described first.

[0216] A base station can only send a PDSCH to a terminal in a BWP if it has successfully accessed the channel in all the basic bandwidths included in the BWP. If the base station has successfully accessed the channel in all the basic bandwidths included in the BWP, it can send a PDCCH (Planning Data Center Communication) to the terminal in the BWP that schedules the PDSCH. The terminal can monitor the PDCCH in an active BWP among the BWPs configured for the terminal. Specifically, the terminal can monitor the PDCCH in the CORESET of an active BWP among the BWPs configured for the terminal. The terminal monitors the PDCCH in only one BWP, thus preventing increased terminal complexity due to operation in unlicensed frequency bands. Furthermore, it prevents a decrease in the terminal's power efficiency in unlicensed frequency bands. However, if the base station only performs transmissions in the BWP when it has successfully accessed the channel in all the basic bandwidths included in the BWP, the spectral efficiency of downlink transmission from the base station to the terminal may be reduced.

[0217] If a base station successfully accesses a channel in even one of the basic bandwidths included in a BWP, the base station can transmit a PDSCH to the terminal in the BWP by using one or more bandwidths where the channel access has been successful. Similarly, if a base station successfully accesses a channel in even one of the basic bandwidths included in a BWP, the base station can transmit a PDCCH that schedules the PDSCH to the terminal in the BWP by using one or more bandwidths where the channel access has been successful. Through this embodiment, the base station can improve the spectral efficiency of PDCCH transmission. However, the terminal cannot identify the basic bandwidths in the one or more basic bandwidths included in the BWP where the base station has successfully accessed a channel. Therefore, the terminal can monitor the PDCCH in the CORESET configured in the BWP. However, if a CORESET is configured on a BWP-by-BWP basis and the base station fails to access a channel in one of the basic bandwidths included in the BWP, the base station cannot use a portion of the CORESET bandwidth and therefore may not be able to transmit the PDCCH in the CORESET. Therefore, the terminal may not be able to receive the PDCCH in the CORESET. Therefore, the base station can configure the CORESET within the basic bandwidth of the BWP. Specifically, if the base station configures the CORESET in the BWP, the base station can configure the CORESET within the basic frequency band. The terminal can assume that the base station can transmit PDCCH within a core set of the basic bandwidth, and then monitor the PDCCH. As the bandwidth size of the BWP configured for the terminal, i.e., the number of core bandwidths, increases, the terminal monitors the PDCCH within an increased number of core sets, since each core set is allowed to be configured within the basic bandwidth. Therefore, there is a drawback: blind decoding of the PDCCH may increase the terminal's complexity and power consumption. Therefore, a method is needed for the terminal to effectively monitor the PDCCH. Specifically, a method is needed whereby the terminal can effectively monitor the PDCCH when the core set is configured within the basic bandwidth, i.e., when the core set has a bandwidth equal to or less than the basic bandwidth. This method will be referred to below. ​ illustrate.

[0218] ​ This illustrates the operation of transmitting PDCCH in a CORESET configured in each basic bandwidth and transmitting PDSCH in a BWP when the base station configuration according to an embodiment of the present disclosure includes one or more basic bandwidths.

[0219] When a base station successfully accesses a channel in each basic bandwidth (including the core set) of a Base Platform Window (BWP), the base station can send a PDCCH (Planned Distribution Message) to the terminal within one of the basic bandwidths where channel access has been successfully achieved. The base station can divide the BWP into multiple basic bandwidths, each including the core set, and can assign a priority to each of these basic bandwidths. Each of the multiple basic bandwidths can have a unique priority. When a base station successfully accesses a channel in each basic bandwidth (including the core set) of a BWP, the base station can determine the basic bandwidth with the highest priority among the basic bandwidths where channel access has been successfully achieved as the bandwidth to send the PDCCH. That is, when a base station successfully accesses a channel in each basic bandwidth (including the core set) of a BWP, the base station can send the PDCCH to the terminal within the basic bandwidth with the highest priority among the basic bandwidths where channel access has been successfully achieved. For ease of explanation, the basic bandwidth with the highest priority among the basic bandwidths where the base station can send the PDCCH and has successfully accessed the channel is called the highest priority basic bandwidth. The terminal can monitor the PDCCH based on the priority of the basic bandwidths. Specifically, the terminal can determine the order in which to monitor the PDCCH based on the priority of the basic bandwidth. When CORESETs are configured within the basic bandwidth, the terminal can monitor the PDCCH sequentially across multiple basic bandwidth CORESETs according to their priorities. For example, if the terminal fails to receive a PDCCH in a CORESET configured in the bandwidth with the highest priority among the basic bandwidths, the terminal monitors the PDCCH in a CORESET configured in the basic bandwidth with the second highest priority. When the terminal receives a PDCCH in one basic bandwidth, monitoring the PDCCH in the remaining basic bandwidths can be omitted. Specifically, when the terminal receives a PDCCH that schedules a PDCCH in one basic bandwidth, monitoring of the PDCCH that schedules a PDCCH can be omitted in the basic bandwidths other than the one where the PDCCH was received.

[0220] Furthermore, the PDCCH can schedule PDCSH transmissions within the basic bandwidth where the base station has already successfully accessed the channel. The PDCCH can also schedule PDCSH transmissions within basic bandwidths other than the highest priority basic bandwidth, and PDSCH transmissions within the highest priority basic bandwidth. The base station can determine one or more basic bandwidths in which to transmit PDSCH based on the highest priority basic bandwidth. The terminal can receive PDSCH based on the PDSCH scheduling information included in the received PDCCH.

[0221] Additionally, the base station can determine the basic bandwidth in which to transmit PDSCH by combining the channel access results in the highest priority basic bandwidth with the channel access results in other basic bandwidths in the corresponding BWP. In a detailed embodiment, when the base station has also successfully accessed a channel in a basic bandwidth adjacent to the highest priority basic bandwidth, the base station can transmit PDSCH based on the highest priority basic bandwidth and the basic bandwidth in which the base station has successfully accessed a channel and which is adjacent to the highest priority basic bandwidth. The base station can transmit PDSCH using a bandwidth that is an integer multiple of the basic bandwidth (e.g., 20MHz*M, where M = {1, 2, 3, 4, ..., N}, and N is a natural number). In another detailed embodiment, the base station can transmit PDSCH using a bandwidth that is obtained by multiplying the basic bandwidth by a power of 2 (e.g., 20MHz*2^L, where L = {0, 1, 2, 3, ..., X}, and X is a natural number). ​ Each LBT unit shown indicates the basic bandwidth.

[0222] ​(a) illustrates a case where a base station transmits PDSCH through a bandwidth that is an integer multiple of the basic bandwidth. Case 1 shows an instance where the base station has successfully accessed the channel in the highest priority basic bandwidth (primary LBT unit) and has failed to access the channel in the second highest priority basic bandwidth (secondary LBT unit). In Case 1, the base station is allowed to transmit PDSCH through one basic bandwidth (first LBT unit). Case 2 shows an instance where the base station has successfully accessed the channel in the highest priority basic bandwidth (primary LBT unit) and the second highest priority basic bandwidth (secondary LBT unit) and has failed to access the channel in the third highest priority basic bandwidth (third-level LBT unit). In Case 2, the base station is allowed to transmit PDSCH through two basic bandwidths (first LBT unit and second LBT unit). Case 3 shows an instance where the base station has successfully accessed the channel in the highest priority basic bandwidth (primary LBT unit), the second highest priority basic bandwidth (secondary LBT unit), and the third highest priority basic bandwidth (third-level LBT unit), and has failed to access the channel in the fourth highest priority basic bandwidth (fourth-level LBT unit). In Case 3, the base station is allowed to transmit PDSCH through three basic bandwidths (first LBT unit, second LBT unit, and third LBT unit). Case 4 shows an instance where the base station has successfully accessed the channel in all (N) basic bandwidths. In Case 4, the base station is allowed to transmit PDSCH through N basic bandwidths (first LBT unit, second LBT unit, third LBT unit, ... and NLBT unit). Case 5 shows an instance where the base station has successfully accessed the channel in the second highest priority basic bandwidth (secondary LBT unit) but failed to access the channel in the highest priority basic bandwidth (primary LBT unit) and the third highest priority basic bandwidth (tertiary LBT unit). In Case 5, the base station is allowed to transmit PDSCH through one basic bandwidth (secondary LBT unit). Case 6 shows an instance where the base station has successfully accessed the channel in the second highest priority basic bandwidth (secondary LBT unit) and the third highest priority basic bandwidth (tertiary LBT unit) but failed to access the channel in the highest priority basic bandwidth (primary LBT unit) and the fourth highest priority basic bandwidth (quadrant LBT unit). In Case 6, the base station is allowed to transmit PDSCH through two basic bandwidths (second LBT unit and third LBT unit). Case 7 shows an instance where the base station has successfully accessed the channel in all basic bandwidths except for the primary LBT unit, which has the highest priority. In this case, PDSCH transmission through (N-1) basic bandwidths (second LBT unit, third LBT unit, NLBT unit) is permitted.Case 8 illustrates an instance where a base station has successfully accessed the channel in the third-highest priority basic bandwidth (Level 3 LBT unit) and failed to access the channel in the highest priority basic bandwidth (Primary LBT unit), the second-highest priority basic bandwidth (Secondary LBT unit), and the fourth-highest priority basic bandwidth (Level 4 LBT unit). In Case 8, the base station is allowed to transmit PDSCH through one basic bandwidth (Level 3 LBT unit). Case 9 illustrates an instance where the base station has successfully accessed the channel in all basic bandwidths except for the highest priority basic bandwidth (Primary LBT unit) and the second-highest priority basic bandwidth (Secondary LBT unit). In Case 9, the base station is allowed to transmit PDSCH through (N-2) basic bandwidths (Level 3 LBT unit, ..., Level N LBT unit). Case 10 illustrates an instance where the base station has successfully accessed the channel only in the lowest priority basic bandwidth (Level N LBT unit). In Case 10, the base station is allowed to transmit PDSCH through one basic bandwidth (Level N LBT unit).

[0223] ​Illustration (b) shows a case where a base station transmits PDSCH through a bandwidth of the size obtained by multiplying the basic bandwidth by a power of 2. Case 1 shows an instance where the base station has successfully accessed the channel in the basic bandwidth with the highest priority (primary LBT unit) and has failed to access the channel in the basic bandwidth with the second highest priority (secondary LBT unit). In Case 1, the base station is allowed to transmit PDSCH through one basic bandwidth (first LBT unit). Case 2 shows an instance where the base station has successfully accessed the channel in both the basic bandwidth with the highest priority (primary LBT unit) and the basic bandwidth with the second highest priority (secondary LBT unit) and has failed to access the channel in at least one of the basic bandwidth with the third highest priority (third-level LBT unit) and the basic bandwidth with the fourth highest priority (fourth-level LBT unit). In Case 2, the base station is allowed to transmit PDSCH through two basic bandwidths (first LBT unit and second LBT unit). Case 3 shows an instance where the base station has successfully accessed the channel in all (N) basic bandwidths. In Case 3, the base station is allowed to transmit PDSCH through N basic bandwidths. Case 4 illustrates an instance where a base station has successfully accessed the channel in the second-highest priority basic bandwidth (secondary LBT unit) but failed to access the channel in the highest priority basic bandwidth (primary LBT unit) and the third-highest priority basic bandwidth (tertiary LBT unit). In Case 4, the base station is allowed to transmit PDSCH through one basic bandwidth (secondary LBT unit). Case 5 illustrates an instance where a base station has successfully accessed the channel in the second-highest priority basic bandwidth (secondary LBT unit) and the third-highest priority basic bandwidth (tertiary LBT unit), failed to access the channel in the highest priority basic bandwidth (primary LBT unit), and failed to access the channel in at least one of the third-highest priority basic bandwidth (tertiary LBT unit) and the fourth-highest priority basic bandwidth (quadrant LBT unit). In Case 5, the base station is allowed to transmit PDSCH through two basic bandwidths (secondary LBT unit and third LBT unit). Case 6 illustrates an instance where a base station has successfully accessed the channel in the third-highest priority basic bandwidth (Level 3 LBT unit) and failed to access the channel in the highest priority basic bandwidth (Primary LBT unit), the second-highest priority basic bandwidth (Secondary LBT unit), and the fourth-highest priority basic bandwidth (Level 4 LBT unit). In Case 6, the base station is allowed to transmit PDSCH through one basic bandwidth (Level 3 LBT unit). Case 7 illustrates an instance where a base station failed to access the channel in the highest priority basic bandwidth (Primary LBT unit) and the second-highest priority basic bandwidth (Secondary LBT unit) and has successfully accessed the channel in (N-2) remaining basic bandwidths (Level 3 LBT units, ..., Level N LBT units).The quantity (N-2) is a power of 2. In case 7, the base station is allowed to transmit PDSCH through (N-2) basic bandwidths (third LBT unit, ..., Nth LBT unit). Case 8 shows an example where the base station has successfully accessed the channel only in the basic bandwidth with the lowest priority (Nth LBT unit). In case 8, the base station is allowed to transmit PDSCH through one basic bandwidth (Nth LBT unit).

[0224] ​ The diagram illustrates the operation in which, when the BWP is configured to include one or more basic bandwidths according to embodiments of the present disclosure, the base station transmits PDCCH in a CORESET configured in each specified basic bandwidth and transmits PDSCH in the BWP according to its priority.

[0225] The base station can divide the BWP into multiple basic bandwidth units, specify multiple priority basic bandwidths for the terminal to monitor the PDCCH, and can transmit the PDCCH only in the specified priority basic bandwidths. The base station can configure CORESET in each specified basic bandwidth. In another detailed embodiment, the base station can specify multiple priority basic bandwidths within the basic bandwidth for configuring CORESET. Furthermore, as mentioned above, the bandwidth of CORESET can be configured separately within the basic bandwidth. The terminal can monitor the PDCCH only in the specified priority basic bandwidth.

[0226] One or more basic bandwidths can be specified in the BWP in which the base station can transmit PDCCH. The base station can transmit PDCCH to the terminal based on the result of channel access within the specified basic bandwidth. Specifically, the base station can transmit PDCCH according to the priority of the specified basic bandwidth based on the result of channel access within the specified basic bandwidth. The base station can transmit PDCCH in the basic bandwidth with the highest priority among the specified basic bandwidths in which channel access has been successful. ​ In the illustrated embodiment, the first basic bandwidth (first LBT unit) and the third basic bandwidth (third LBT unit) are designated as the basic bandwidth capable of transmitting PDCCH. ​ In the illustrated embodiment, when the base station has successfully accessed the channel in the first basic bandwidth (first LBT unit) and the third basic bandwidth (third LBT unit), the base station can transmit PDCCH in the first basic bandwidth (first LBT unit).

[0227] The terminal can monitor the PDCCH within a specified basic bandwidth. The terminal can monitor the PDCCH based on the priority of the specified basic bandwidth. Specifically, the terminal can determine the order of the specified basic bandwidths to monitor the PDCCH based on the priority of the specified basic bandwidth. For example, when the terminal fails to receive the PDCCH in the CORESET configured in the highest priority bandwidth of the specified basic bandwidth, the terminal monitors the PDCCH in the second highest priority specified basic bandwidth. When the terminal receives the PDCCH in one specified basic bandwidth, it can omit monitoring the PDCCH in the remaining specified basic bandwidth. Specifically, when the terminal receives the PDCCH scheduled for PDSCH in one basic bandwidth, it can omit monitoring the PDCCH scheduled for PDSCH in the remaining specified basic bandwidth.

[0228] Furthermore, the PDCCH can schedule PDCSH transmissions within the basic bandwidth where the base station has successfully established channel access. The PDCCH can schedule PDCSH transmissions within basic bandwidths other than the highest priority basic bandwidth, and PDSCH transmissions within the highest priority basic bandwidth. The base station can transmit PDCCHs within the highest priority basic bandwidth, which is the basic bandwidth with the highest priority among the basic bandwidths where the base station has successfully established channel access. Therefore, the highest priority basic bandwidth corresponds to the basic bandwidth with the highest priority among the designated basic bandwidths where the base station has successfully established channel access. The base station can determine the basic bandwidth within which to transmit PDSCHs based on the highest priority basic bandwidth. The terminal can receive PDSCHs based on the PDSCH scheduling information included in the received PDCCH.

[0229] Additionally, the base station can determine the basic bandwidth in which to transmit PDSCH by combining the channel access results in the highest priority basic bandwidth with the channel access results in other basic bandwidths of the corresponding BWP. In a detailed embodiment, when the base station has also successfully accessed a channel in a basic bandwidth adjacent to the highest priority basic bandwidth, the base station can transmit PDSCH based on the highest priority basic bandwidth and the basic bandwidth in which the base station has successfully accessed a channel and which is adjacent to the highest priority basic bandwidth. The base station can transmit PDSCH using a bandwidth that is an integer multiple of the basic bandwidth (e.g., 20MHz*M, where M = {1, 2, 3, 4, ..., N}, and N is a natural number). In another detailed embodiment, the base station can transmit PDSCH using a bandwidth that is obtained by multiplying the basic bandwidth by a power of 2 (e.g., 20MHz*2^L, where L = {0, 1, 2, 3, ..., X}, and X is a natural number). ​ Each LBT unit shown indicates the basic bandwidth. As mentioned above, in ​In the embodiment shown, two basic bandwidths (the first LBT unit and the third LBT unit) are designated as the basic bandwidths that can be used to send PDCCH.

[0230] ​Case (a) illustrates a scenario where a base station transmits PDSCH through a bandwidth that is an integer multiple of the basic bandwidth. Case 1 shows an instance where the base station has successfully accessed the channel in the first basic bandwidth (first LBT unit), which is the highest priority basic bandwidth (primary LBT unit), but failed to access the channel in the second basic bandwidth (secondary LBT unit). In Case 1, the base station is allowed to transmit PDSCH through one basic bandwidth (first LBT unit). Case 2 shows an instance where the base station successfully accesses the channel in the first basic bandwidth (primary LBT unit) and the second basic bandwidth (secondary LBT unit), which are the highest priority basic bandwidths, but failed to access the channel in the third basic bandwidth (third LBT unit). In Case 2, the base station is allowed to transmit PDSCH through two basic bandwidths (first LBT unit and second LBT unit). Case 3 shows an instance where the base station has successfully accessed the channel in the first basic bandwidth (primary LBT unit), the second basic bandwidth (secondary LBT unit), and the third bandwidth (tertiary LBT unit), which are the highest priority basic bandwidths (primary LBT unit), but failed to access the channel in the Nth basic bandwidth (Nth LBT unit). In Case 3, the base station is allowed to transmit PDSCH through three basic bandwidths (first LBT unit, second LBT unit, third LBT unit). Case 4 shows an example where the base station has successfully accessed the channel in all (N) basic bandwidths. In Case 4, the base station is allowed to transmit PDSCH through N basic bandwidths (first LBT unit, second LBT unit, third LBT unit... NLBT unit). The base station transmits PDSCH through N basic bandwidths (first LBT unit, second LBT unit, third LBT unit,... NLBT unit). Case 5 shows an example where the base station has successfully accessed the channel in the third basic bandwidth (third LBT unit), which is the second highest priority basic bandwidth (secondary LBT unit), and has failed to access the channel in the first basic bandwidth (first LBT unit), which is the highest priority basic bandwidth (primary LBT unit), and the Nth basic bandwidth (Nth LBT unit). In Case 5, the base station is allowed to transmit PDSCH through one basic bandwidth (third LBT unit). Case 6 illustrates an instance where a base station has successfully accessed the channel in the third basic bandwidth (third LBT unit), which is the second highest priority basic bandwidth (secondary LBT unit), and in all basic bandwidths from the fourth to the nth basic bandwidth, but has failed to access the channel in the first basic bandwidth (first LBT unit), which is the highest priority bandwidth (primary LBT unit). In Case 6, the base station is allowed to transmit PDSCH through (N-2) basic bandwidths (third LBT unit, ..., NLBT unit). Case 7 illustrates an instance where, when the nth basic bandwidth is configured as the third highest priority basic bandwidth, the base station fails to access the channel in the first and second highest priority basic bandwidths.In case 7, the base station is allowed to transmit PDSCH through a basic bandwidth (Nth LBT unit).

[0231] ​ (b) illustrates a case where a base station transmits PDSCH through a bandwidth of the size obtained by multiplying the basic bandwidth by a power of 2. Case 1 shows an instance where the base station has successfully accessed the channel in the first basic bandwidth (first LBT unit), which is the basic bandwidth with the highest priority (primary LBT unit), and has failed to access the channel in the second basic bandwidth (second LBT unit). In Case 1, the base station is allowed to transmit PDSCH through one basic bandwidth (first LBT unit). Case 2 shows an instance where the base station has successfully accessed the channel in the first basic bandwidth (first LBT unit) and the second basic bandwidth (second LBT unit), which are the basic bandwidths with the highest priority (primary LBT unit), and has failed to access the channel in at least one of the third basic bandwidth (third LBT unit) and the fourth basic bandwidth (fourth LBT unit). In Case 2, the base station is allowed to transmit PDSCH through two basic bandwidths (first LBT unit and second LBT unit). Case 3 shows an instance where the base station has successfully accessed the channel in all (N) basic bandwidths. In Case 3, the base station is allowed to transmit PDSCH through N basic bandwidths. Case 4 illustrates an instance where a base station has successfully accessed the channel in the third basic bandwidth (third LBT unit), which is the second highest priority basic bandwidth (secondary LBT unit), and failed to access the channel in the first basic bandwidth (first LBT unit), which is the highest priority basic bandwidth (primary LBT unit), and the fourth basic bandwidth (fourth LBT unit). In Case 4, the base station is allowed to transmit PDSCH through one basic bandwidth (third LBT unit). Case 5 illustrates an instance where a base station has successfully accessed the channel in the third basic bandwidth (third LBT unit), which is the second highest priority basic bandwidth (secondary LBT unit), and in all basic bandwidths after the third basic bandwidth (third LBT unit), and failed to access the channel in the first basic bandwidth (first LBT unit), which is the highest priority basic bandwidth (primary LBT unit). In Case 5, the base station is allowed to transmit PDSCH through (N-2) basic bandwidths (third LBT unit, ..., NLBT unit). The number (N-2) is a power of 2. Case 6 illustrates an instance where a base station fails to access the channel in both the first and second highest priority basic bandwidths when the Nth basic bandwidth is configured as the third highest priority basic bandwidth. In Case 6, the base station is allowed to transmit PDSCH through one basic bandwidth (NLBT element).

[0232] ​The illustration shows the operation of a base station transmitting PDCCH in a CORESET configured in each specified basic bandwidth according to an embodiment of the present disclosure when the BWP is configured to include one or more basic bandwidths according to an embodiment of the present disclosure. One or more basic bandwidths for transmitting PDCCH are specified and the base station transmits PDCCH in the BWP in a CORESET configured in each specified basic bandwidth according to the specified basic bandwidth.

[0233] One or more basic bandwidths in which the base station can transmit PDCCH can be specified in the BWP. The base station can transmit PDCCH to the terminal based on the result of channel access in the specified basic bandwidth. The base station can configure CORESET in each specified basic bandwidth. In another detailed embodiment, the base station can specify one or more basic bandwidths in which PDCCH can be transmitted within the basic bandwidth in which CORESET is configured. Furthermore, as mentioned above, the bandwidth of CORESET can be configured separately within the basic bandwidth. Furthermore, all priorities of the specified basic bandwidth for PDCCH transmission can be the same. Specifically, the base station can transmit PDCCH in one of the specified basic bandwidths in which channel access has been successful. The base station can consider scheduling algorithms, etc., to determine the basic bandwidth to transmit PDCCH. Furthermore, the basic bandwidths that can be used to schedule PDSCH through the specified basic bandwidth may not be adjacent to each other and may not intersect each other. ​ In the illustrated embodiment, the first basic bandwidth (first LBT unit) and the third basic bandwidth (third LBT unit) are designated as the basic bandwidth capable of transmitting PDCCH. ​ In the illustrated embodiment, when the base station has successfully accessed the channel in the first basic bandwidth (first LBT unit) and the third basic bandwidth (third LBT unit), the base station may transmit PDCCH in one of the first basic bandwidth (first LBT unit) and the third basic bandwidth (third LBT unit).

[0234] The terminal can monitor the PDCCH in all specified basic bandwidths. When the terminal has successfully received the PDCCH in one specified basic bandwidth, it can omit monitoring the PDCCH in the remaining specified basic bandwidth. Specifically, when the terminal receives the PDCCH that schedules PDCSH in one basic bandwidth, it can omit monitoring the PDCCH that schedules PDSCH in the remaining specified basic bandwidth.

[0235] Furthermore, the PDCCH can schedule PDCSH transmissions within a specified basic bandwidth where the base station has successfully established channel access. The PDCCH can also schedule PDCSH transmissions within a basic bandwidth other than the specified basic bandwidth, as well as PDCSH transmissions within the specified basic bandwidth. The terminal can receive the PDSCH based on the PDSCH scheduling information included in the received PDCCH.

[0236] Furthermore, the base station can determine the basic bandwidth in which to transmit PDSCH by combining the channel access results in the specified basic bandwidth with the channel access results in other basic bandwidths of the corresponding BWP. In a detailed embodiment, when the base station has also successfully accessed the channel in a basic bandwidth adjacent to the specified basic bandwidth, the base station can transmit PDSCH based on the specified basic bandwidth and the basic bandwidth in which the base station has successfully accessed the channel and which is adjacent to the specified basic bandwidth. The base station can transmit PDSCH with a bandwidth of size obtained by multiplying the basic bandwidth by a power of 2 (e.g., 20MHz * 2^L, where L = {0, 1, 2, 3, ..., X} and X is a natural number). ​ Each LBT unit shown indicates the basic bandwidth. As mentioned above, in ​ In the illustrated embodiment, two basic bandwidths (the first LBT unit and the third LBT unit) are designated as the basic bandwidths capable of transmitting PDCCH. Furthermore, in ​ In the illustrated embodiment, the base station transmits PDSCH using a bandwidth of a size obtained by multiplying the basic bandwidth by a power of 2. Case 1 shows an example where the base station has successfully accessed the channel in a first basic bandwidth (first LBT unit), which is the designated basic bandwidth, and has failed to access the channel in a second basic bandwidth (second LBT unit). In Case 1, the base station is allowed to transmit PDSCH through one basic bandwidth (first LBT unit). Case 2 shows an example where the base station has successfully accessed the channel in both the first and second basic bandwidths (second LBT units), which are designated basic bandwidths, and has failed to access the channel in at least one of the third and fourth basic bandwidths (fourth LBT units). In Case 2, the base station is allowed to transmit PDSCH through both basic bandwidths (first LBT unit and second LBT unit). Case 3 shows an example where the base station has successfully accessed the channel in the third basic bandwidth (third LBT unit), which is the designated basic bandwidth, and has failed to access the channel in both the first and fourth basic bandwidths (fourth LBT units). In Case 3, the base station is allowed to transmit PDSCH through one basic bandwidth (third LBT unit). Case 4 shows an example where the base station has successfully accessed the channel in the third basic bandwidth (third LBT unit) and all basic bandwidths after the third basic bandwidth (third LBT unit), but failed to access the channel in the first basic bandwidth (first LBT unit). In Case 4, the base station is allowed to transmit PDSCH through (N-2) basic bandwidths (third LBT unit, ..., Nth LBT unit). The number (N-2) is a power of 2.

[0237] The base station can configure PDSCH scheduling information based on the active BWP. The terminal can determine the resource allocation (RA) field of the DCI of the PDCCH, which serves as the scheduling PDSCH, based on the active BWP. The terminal can receive the PDSCH based on the above determination. As in the above embodiment, the base station can determine the combination of basic bandwidths for transmitting the PDSCH based on whether channel success exists in each of the multiple basic bandwidths included in the BWP. Therefore, after performing channel access, the base station needs to make a final decision on the RA field value of the DCI. Furthermore, after performing channel access, the base station needs to make a final decision on the size of the resources in which the PDSCH will be transmitted. Therefore, the complexity of the base station's operations in scheduling PDSCH transmission and configuring the PDCCH may be increased. Therefore, a method is needed for indicating the resources used for PDSCH transmission in the PDCCH.

[0238] The base station can configure the RA field of the DCI to be divided into a first field indicating the basic bandwidth including resources assigned to PDSCH transmission and a second field indicating resources assigned to PDSCH transmission within the basic bandwidth indicated by the first field. Specifically, the first field can indicate a basic bandwidth index or a combination of basic bandwidth indices, which identifies the basic bandwidth including resources assigned to PDSCH transmission. Furthermore, the base station can configure the value of the RA field of the DCI such that the RA field indicates a basic bandwidth index or a combination of basic bandwidth indices and resources assigned to PDSCH transmission within the basic bandwidth. Specifically, the terminal can determine the resources assigned to PDSCH transmission based on the location of the basic bandwidth for transmitting PDSCH and the value of the RA field included in the PDCCH. For example, according to... ​ (a) ​ (a) and ​ In the embodiments shown, when a PDCCH is transmitted in a unit bandwidth (primary LBT unit) with the highest priority, the RA field can indicate frequency resources including the unit bandwidth (primary LBT unit) with the highest priority (e.g., cases 1, 2, 3, and 4). When a PDCCH is transmitted in a unit bandwidth (secondary LBT unit) with the second highest priority, the RA field can indicate frequency resources including the unit bandwidth (secondary LBT unit) with the second highest priority (e.g., cases 5, 6, and 7).

[0239] A base station can transmit a PDCCH within a BWP and use the PDCCH to schedule PDSCH transmissions in a different BWP than the one transmitting the PDCCH. This scheduling is called BWP handover. In the event of a BWP handover as described above, the terminal may need time to retune to the BWP from which the base station is transmitting the PDSCH in order to receive the PDSCH according to the BWP handover. Specifically, BWP handover can include changing the center frequency of the BWP, changing the frequency band of the BWP, and changing the bandwidth of the BWP. Depending on the specific situation, the terminal may need a time gap of several hundred μs. When the PDSCH is transmitted in a licensed frequency band, the base station can schedule PDSCH transmission to ensure the aforementioned time gap. However, considering that devices using unlicensed frequency bands, such as Wi-Fi devices, perform CCA in 9 μs intervals, there is a possibility that another wireless communication device may use the frequency resources corresponding to the BWP being switched during the time gap that occurs during the BWP handover when the PDSCH is transmitted in an unlicensed frequency band. Therefore, during a BWP handover, the base station can transmit reserved signals in the changed BWP. Specifically, during BWP handover, the base station can send a reserved signal in the changed BWP for the frequency resources in which PDSCH will be transmitted. In a detailed embodiment, the base station can send the reserved signal in the changed BWP for the frequency resources in which PDSCH will be transmitted during the time slot used for BWP change, based on the Time Domain Resource Allocation (TDRA) of the PDSCH scheduled in the changed BWP during BWP handover. BWP change can include at least one of changing the center frequency of the BWP, changing the frequency band of the BWP, and changing the bandwidth of the BWP. The base station can generate the reserved signal by extending the CP of the OFDM symbols used for the PDSCH to be transmitted by the base station.

[0240] This specification provides a method for receiving downlink control and data channels and a method for transmitting uplink control and data channels, which allows bandwidth-based portion (BWP) operation in a carrier for NR-U. This specification provides a method for receiving downlink control and data channels and a method for transmitting uplink control and data channels, which are performed in a BWP configured with one or more talk-before (LBT) bandwidths present in a carrier. Examples of the methods presented in this specification relate to a method for allocating resources for downlink control channel transmission and resources for downlink data channel transmission according to the configuration of the guard band within the carrier when a base station performs downlink channel transmission to a terminal in a BWP configured with two or more LBT bandwidths (or LBT subbands) present in a carrier, and indicating information related to resource allocation. Furthermore, the method relates to a method for a terminal to receive downlink control and downlink data channels on resources assigned from the base station. Furthermore, the method proposed in this specification relates to a method for allocating resources for the transmission of uplink control channels and uplink data channels according to the configuration of the in-carrier guard band when a terminal performs uplink channel transmission to a base station, and indicating information related to resource allocation. Additionally, the method relates to a method by which a terminal transmits uplink control channels and uplink data channels using resources scheduled (allocated) from the base station.

[0241] ​ This is a diagram illustrating the in-carrier guard band and carrier guard band in a BWP configured by one or more LBT subbands of a broadband carrier according to an embodiment of this specification.

[0242] Reference ​ This specification describes in-carrier guard bands and carrier guard bands according to embodiments thereof. An in-carrier guard band can be a guard band positioned within a predetermined bandwidth according to a pre-configured standard positioned in a BWP within a carrier. For example, an in-carrier guard band can indicate guard bands positioned at 20 MHz intervals in a BWP within a carrier having an 80 MHz bandwidth. A carrier guard band can indicate guard bands positioned at both ends of a wideband carrier. A carrier guard band can be configured not to be allocated as a resource for channel transmission. Conversely, an in-carrier guard band can be configured to be allocated as a resource for channel transmission. If a base station allocates an in-carrier guard band as a resource for channel transmission, the base station is required to notify the terminal that the resource is available for channel transmission. The channels described in this specification can have the meaning of including control channels and data channels, and channel transmission can have the same meaning as data transmission.

[0243] ​This is a diagram illustrating the number of Physical Resource Blocks (PRBs) that can be continuously used in a BWP with a bandwidth of 20MHz, 40MHz, or 80MHz according to embodiments of this specification.

[0244] ​ This is a diagram illustrating the number of physical RBs that can be used as in-carrier guard bands in a BWP having a bandwidth of 20MHz, 40MHz, or 80MHz according to embodiments of this specification.

[0245] Reference ​ In a BWP with a bandwidth of 20 MHz, a sub-band can be configured with 51 PRBs. In a BWP with a bandwidth of 40 MHz, a sub-band can be configured with 50 PRBs, while the in-carrier guard band between two adjacent sub-bands can be configured with six PRBs. In a BWP with a bandwidth of 80 MHz, a sub-band can be configured with 49 or 50 PRBs, while the in-carrier guard band between two adjacent sub-bands can be configured with six or seven PRBs.

[0246] Reference ​ In a BWP with a bandwidth of 20MHz, the number of consecutively available subbands is one, while 51 PRBs can be used as subbands. In a BWP with a bandwidth of 40MHz, the number of consecutively available subbands is two, and 106(50+6+50, see [reference]). ​ ) PRBs can be used for each subband. In a BWP with an 80MHz bandwidth, the number of consecutively available subbands is four, 217(50+6+49+7+49+6+50, see [link]). ​ One PRB can be used for each sub-band.

[0247] also, ​ This is a diagram illustrating the number of physical RBs that can be used for each LBT subband in a BWP with a bandwidth of 20MHz, 40MHz, or 80MHz according to an embodiment of this specification. ​ The intra-carrier protection shown can have the same meaning as the intra-carrier protection band described above.

[0248] When a downlink control channel is received, the terminal may not be able to identify whether the in-carrier guard band has been allocated as a resource for transmitting control channels from the base station. Simultaneously, the terminal can receive an indication of available LBT (Large Bit By) subbands for channel transmission from the base station via a bitmap using the Group Common (GC)-PDCCH. However, before receiving the indication of available LBT subbands from the base station via the GC-PDCCH, the terminal cannot determine whether the in-carrier guard band has been allocated as a resource for both control and data channel transmission. Therefore, when the base station wants to send a downlink control channel (i.e., PDCCH) to the terminal, the base station can allow the terminal to configure a control resource set (CORESET) in resources other than the in-carrier guard band. The base station can send the PDCCH to the terminal on CORESET resources. That is, a CORESET can be allocated in available LBT subbands, and furthermore, a CORESET can be allocated to frequency resources other than the in-carrier guard band in available LBT subbands. The base station can configure the terminal to monitor the PDCCH on CORESETs configured with resources other than the in-carrier guard band. The terminal can monitor the PDCCH on CORESET resources configured by the base station and configured with resources other than the in-carrier guard band, and can perform blind detection of the PDCCH.

[0249] Simultaneously, the base station can indicate the available LBT subbands to the terminal via GC-PDCCH at time points other than the DL burst start time using a bitmap. If the terminal receives the GC-PDCCH, there may be no ambiguity between the terminal and the base station regarding whether to allocate the in-carrier guard band as a resource for channel transmission. However, if the terminal fails to detect the GC-PDCCH even though the base station indicates the availability of consecutive LBT subbands for channel transmission, the terminal cannot know whether the in-carrier guard band is available for channel transmission. Therefore, even if the base station configures the in-carrier guard band as available for channel transmission via GC-PDCCH, the terminal may not recognize this configuration. Thus, ambiguity related to the allocation of resources for the in-carrier guard band (whether the in-carrier guard band is used for channel transmission) may exist between the terminal and the base station.

[0250] In other words, the base station can consider whether the in-carrier guard band can be used for channel transmission and allocate resources (e.g., CORESET) for channel transmission, which allows the terminal to monitor the PDCCH. That is, when the in-carrier guard band is not allowed for channel transmission, resources for channel transmission can be configured on the sub-bands within the BWP identified by the in-carrier guard band. The base station can then instruct the terminal to perform PDCCH monitoring for receiving the PDCCH in the resources for channel transmission. The base station can then transmit the PDCCH using the resources for channel transmission. Subsequently, the terminal can perform blind detection of the PDCCH in the resources for channel transmission. The base station can send information to the terminal related to whether the in-carrier guard band has been allocated as resources for channel transmission by considering whether the in-carrier guard band is available as resources for channel transmission. The base station can then instruct each sub-band in the BWP identified by the in-carrier guard band whether it is used for downlink channel transmission. The bitmap type can indicate information related to whether the in-carrier guard band has been allocated as a resource for channel transmission by taking into account the availability of the in-carrier guard band for channel transmission, and whether each subband is used for downlink channel transmission.

[0251] Therefore, this specification proposes a method for a base station to indicate whether a guard band within a carrier is available as a resource for channel transmission. Specifically, this specification proposes a method for indicating this via downlink control information (DCI) signaling, which is a dynamic scheduling method.

[0252] In downlink transmission, a base station can perform channel access in units of LBT bandwidth within a BWP configured with two or more LBT bandwidths (or LBT subbands). Whether consecutive LBT subbands in a BWP are available for channel transmission can be determined based on whether the in-carrier guard band is available as a resource for channel transmission. Therefore, when the base station successfully performs channel access, it needs to indicate to the terminal whether resource allocation is performed considering whether the in-carrier guard band is available for channel transmission or whether it is performed considering whether the in-carrier guard band is unavailable for channel transmission.

[0253] The terminal can receive Frequency Domain Resource Allocation (FDRA) information from the base station via DCI. However, the terminal cannot know the result of channel access performed by the base station in a downlink BWP configured with two or more LBT bandwidths (or LBT subbands), where the base station configures the LBT bandwidth (or LBT subbands) for the terminal. Therefore, when consecutive LBT subbands in the BWP are available for channel transmission, the terminal cannot know whether the base station performs downlink resource allocation by considering the availability of in-carrier guard bands for channel transmission or based on resources other than the in-carrier guard bands. Therefore, the base station can send signaling to the terminal indicating whether resource allocation for downlink transmission has been performed by considering the availability of in-carrier guard bands for channel transmission. When the terminal receives the signaling, there may be no ambiguity related to whether the in-carrier guard bands were allocated as resources for channel transmission when frequency resources are allocated for downlink transmission between the terminal and the base station. The terminal can receive PDSCH from the base station based on the frequency domain resource allocation information for downlink transmission sent via DCI.

[0254] When a base station performs resource allocation for downlink channel transmission to a terminal, it is required to indicate whether the resource allocation is performed by considering whether the in-carrier guard band is available for channel transmission or by considering whether the in-carrier guard band is unavailable for channel transmission. The indication method can be as follows.

[0255] ​

[0256] Method 1 is a method for a base station to execute signaling from a terminal via RRC configuration related to whether or not an intra-carrier guard band can be allocated as a resource for channel transmission.

[0257] Through RRC configuration, the in-carrier guard band can be configured to be unallocated as a resource for data channel transmission. The base station can allocate frequency resources other than the in-carrier guard band as resources for the data channel. The terminal can assume that frequency resources other than the in-carrier guard band are allocated for data channel transmission. The terminal can receive the data channel by interpreting multiple frequency domain resource allocation information used for the data channel.

[0258] Conversely, through RRC configuration, the in-carrier guard band can be configured to be allocated as a resource for channel transmission. The base station can determine whether the in-carrier guard band is available as a resource for channel transmission. Specifically, the base station can determine whether to use the RBs within which the actual in-carrier guard band is located as resources for channel transmission based on the results of channel access to consecutive LBT subbands. Therefore, a method can be considered whereby the base station indicates via DCI whether the RBs within which the actual in-carrier guard band is located are used as resources for channel transmission. That is, the terminal can assume that frequency resources including the in-carrier guard band are available for channel transmission. The DCI can indicate to the terminal whether the RBs within which the actual in-carrier guard band is located are used as resources for channel transmission. The terminal can interpret the indicated information to receive the data channel by interpreting multiple frequency domain resource allocation information for the data channel.

[0259] The aforementioned RRC configuration can be applied to both downlink and uplink channel transmissions. Specifically, whether the in-carrier guard band is available as a resource for channel transmission can be configured equally for both downlink and uplink channel transmissions via RRC.

[0260] On the other hand, configuration can be applied through separate RRC configurations for downlink and uplink channel transmissions. Alternatively, configurations via RRC can be applied only to downlink channel transmissions.

[0261] In the case of uplink channel transmission, the resources scheduled for the terminal are allocated to consecutive LBT subbands, and all consecutive LBT subbands can successfully access the channel. The terminal can perform uplink channel transmission within the scheduled resources allocated to the consecutive LBT subbands. If the base station schedules resources allocated to consecutive LBT subbands, it is not necessary to indicate to the terminal whether the in-carrier guard band is available as a resource for channel transmission. This is because the base station can perform resource allocation for DCI to the terminal by considering whether the in-carrier guard band is available for channel transmission. Therefore, if the terminal successfully accesses the channel in consecutive LBT subbands, it is expected that the terminal will transmit the uplink channel to the base station using the scheduled resources of consecutive LBT subbands including the in-carrier guard band. Therefore, there is no ambiguity between the terminal and the base station related to the in-carrier guard band. Therefore, in the case of uplink transmission, it is not necessary to configure RRC whether the in-carrier guard band is available as a resource for channel transmission.

[0262] However, in the case of downlink transmission, even if not all consecutive LBT subbands are successfully accessed in the channel, downlink transmission can still be performed using a portion of the LBT subbands that have already been successfully accessed. Therefore, an RRC configuration indicating whether the in-carrier guard band is available as a resource for downlink channel transmission may be necessary. Similar to the downlink transmission case, also in the case of uplink channel transmission, if the scheduled resources are allocated to consecutive LBT subbands, and not all consecutive LBT subbands are successfully accessed in the channel, uplink channel transmission is possible within a portion of the already successful LBT subbands. In this case, even in the case of uplink channel transmission, an RRC configuration indicating whether the in-carrier guard band is available as a resource for uplink transmission may be necessary.

[0263] ​

[0264] Method 2 employs dynamic signaling, specifically, it involves the base station using DCI to signal whether the guard band within the carrier is available for allocation as a resource for channel transmission.

[0265] a) As an explicit signaling method, the base station can indicate whether an in-carrier guard band is included in the resources used to receive the PDSCH through a field having one bit included in the DCI of the PDSCH scheduling. Specifically, the base station can indicate information related to all RBs in which the in-carrier guard band is located being included in the resources of the scheduled PDSCH through the DCI of the PDSCH scheduling. The terminal can receive the DCI, interpret the Frequency Domain Resource Allocation (FDRA) information indicated from the DCI, and ultimately identify the frequency domain resource allocation information through which the PDSCH is transmitted.

[0266] (b) As an implicit signaling method, the base station can notify the terminal of frequency domain resource allocation information assigned for PDSCH transmission based on the result of channel access performed by the base station. Specifically, the base station can individually indicate to the terminal the LBT subbands allocated for PDSCH transmission. Alternatively, the base station can send frequency domain resource allocation information jointly encoded with DCI including information on the LBT subbands. When the base station sends frequency domain resource allocation information to the terminal, the terminal can use this information to determine that the allocation is for consecutive LBT subbands. The terminal can determine that the base station has performed resource allocation for PDSCH transmission by considering that the in-carrier guard band is available for channel transmission. Simultaneously, when the base station sends frequency domain resource allocation information to the terminal, the terminal can determine that the allocation is not for consecutive LBT subbands by using this information. When the terminal receives frequency domain resource allocation information via DCI, the terminal can determine that the base station has performed resource allocation for PDSCH transmission by considering that the in-carrier guard band is unavailable for channel transmission.

[0267] ​

[0268] The base station can use RRC configuration to indicate whether the in-carrier guard band is available as a resource for channel transmission. If the in-carrier guard band is indicated to be available as a resource for channel transmission, then when the base station allocates resources for downlink transmission, it can include the RBs for the in-carrier guard band based on the BWP configured for the terminal. Whether the RBs for the in-carrier guard band are used for actual downlink transmission frequency resource allocation can be determined by the FDRA value of the DCI. An RB index is required to allocate frequency resources for downlink transmission, which can be indicated by the FDRA value of the DCI. The RB indexing method can be to index the RBs for the in-carrier guard band last, rather than to index the RBs that include the RBs for the in-carrier guard band consecutively. The reason for using the RB indexing method is that the FDRA value of the DCI allows the base station to indicate whether the actual in-carrier guard band is available for channel transmission to the terminal, and allows the terminal to determine whether the in-carrier guard band was used when performing actual resource allocation scheduling. In other words, if the base station fails to successfully access the channel in consecutive LBT subbands even after indicating to the terminal via RRC signaling that the in-carrier guard band is available as a resource for channel transmission, then the in-carrier guard band is not allowed to be allocated to the terminal. Since the terminal cannot know whether the base station has successfully accessed the channel, the terminal cannot be allocated the in-carrier guard band to prevent the terminal from interpreting the FDRA differently based on whether the base station has successfully accessed the channel. For example, as... ​As shown in the two LBT subbands of the 40MHz carrier, the first LBT subband can be configured with 50 RBs, the second LBT subband can be configured with 50 RBs, and the in-carrier guard band can be configured with six RBs. The 50 RBs included in the first LBT subband and the 50 RBs included in the second LBT subband can be indexed from index number 0 to 99, and the six RBs included in the in-carrier guard band can be indexed from index number 100 to 105. As a method for the base station to allocate resources for downlink transmission, there are two methods: one for sending the start position and length of the RB to the terminal using the Resource Indication Value (RIV) field of the DCI and allocating resources for PDSCH transmission; and another for binding one or more RBs to configure an RB group (RBG) and notifying the location of the allocated resources using a bitmap. In these methods, regardless of whether the base station successfully accesses the channel, the base station can individually send information (FDRA information) to the terminal related to the RBs included in the in-carrier guard band being allocated as resources for PDSCH transmission. Terminals can receive PDSCH by jointly interpreting FDRA information using the above indexing method, regardless of whether the base station has successfully accessed the channel.

[0269] ​ This is a block diagram illustrating the configuration of a UE and a base station according to an embodiment of the present invention. In embodiments of this disclosure, the UE can be implemented using various types of wireless communication devices or computing devices that ensure portability and mobility. The UE can be referred to as User Equipment (UE), Station (STA), Mobile Subscriber (MS), etc. Furthermore, in embodiments of the present invention, the base station controls and manages cells (e.g., macro cells, femtocells, picocells, etc.) corresponding to the service area, and performs functions such as signal transmission, channel designation, channel monitoring, self-diagnosis, and relaying. The base station can be referred to as a Next Generation Node B (gNB) or Access Point (AP).

[0270] As shown in the accompanying drawings, the UE 100 according to an embodiment of the present disclosure may include a processor 110, a communication module 120, a memory 130, a user interface 140, and a display unit 150.

[0271] First, the processor 110 can execute various instructions or programs and process data within the UE 100. Furthermore, the processor 110 can control the overall operation of each unit including the UE 100 and can control the transmission / reception of data between the units. Here, the processor 110 can be configured to perform operations according to the embodiments described herein. For example, the processor 110 can receive time slot configuration information, determine a time slot configuration based on the time slot configuration information, and perform communication according to the determined time slot configuration.

[0272] Next, the communication module 120 can be an integrated module that uses a wireless communication network to perform wireless communication and uses a wireless LAN to perform wireless LAN access. For this purpose, the communication module 120 can include multiple network interface cards (NICs), such as cellular communication interface cards 121 and 122 and an unlicensed band communication interface card 123, either internally or externally. In the accompanying drawings, the communication module 120 is shown as a monolithic integrated module; however, unlike the drawings, each network interface card can be arranged independently depending on the circuit configuration or usage.

[0273] Cellular communication interface card 121 can transmit or receive radio signals with at least one of base station 200, external device, and server using a mobile communication network and provide cellular communication services in a first frequency band based on instructions from processor 110. According to an embodiment, cellular communication interface card 121 may include at least one NIC module using a frequency band less than 6 GHz. At least one NIC module of cellular communication interface card 121 can independently perform cellular communication with at least one of base station 200, external device, and server in accordance with cellular communication standards or protocols in the sub-6 GHz frequency band supported by the corresponding NIC module.

[0274] Cellular communication interface card 122 can transmit or receive radio signals with at least one of base station 200, external device, and server using a mobile communication network and provide cellular communication services in a second frequency band based on instructions from processor 110. According to an embodiment, cellular communication interface card 122 may include at least one NIC module using a frequency band greater than 6 GHz. At least one NIC module of cellular communication interface card 122 can independently perform cellular communication with at least one of base station 200, external device, and server in accordance with cellular communication standards or protocols in a frequency band above 6 GHz supported by the corresponding NIC module.

[0275] The unlicensed frequency band communication interface card 123 transmits or receives radio signals with at least one of the base station 200, external devices, and servers by using a third frequency band that is an unlicensed frequency band, and provides unlicensed frequency band communication services based on instructions from the processor 110. The unlicensed frequency band communication interface card 123 may include at least one NIC module using an unlicensed frequency band. For example, the unlicensed frequency band may be a 2.4 GHz or 5 GHz band. At least one NIC module of the unlicensed frequency band communication interface card 123 can independently or non-independently perform wireless communication with at least one of the base station 200, external devices, and servers according to the unlicensed frequency band communication standard or protocol supported by the corresponding NIC module.

[0276] The memory 130 stores the control program used in the UE 100 and its various data. Such a control program may include a prescribed program required to perform wireless communication with at least one of the base station 200, external devices, and servers.

[0277] Next, the user interface 140 includes various input / output means configured in the UE 100. In other words, the user interface 140 can use various input means to receive user input, and the processor 110 can control the UE 100 based on the received user input. Furthermore, the user interface 140 can use various output means to execute output based on instructions from the processor 110.

[0278] Next, the display unit 150 outputs various images on the display screen. The display unit 150 can output various display objects, such as content executed by the processor 110 or a user interface, based on control instructions from the processor 110.

[0279] Furthermore, the base station 200 according to an embodiment of the present invention may include a processor 210, a communication module 220, and a memory 230.

[0280] First, the processor 210 can execute various instructions or programs and process the internal data of the base station 200. Furthermore, the processor 210 can control the overall operation of each unit in the base station 200 and control the transmission and reception of data between the units. Here, the processor 210 can be configured to perform operations according to the embodiments described in this invention. For example, the processor 210 can notify time slot configurations with signals and perform communication based on the time slot configurations notified by the used signals.

[0281] Next, the communication module 220 can be an integrated module that uses a wireless communication network to perform wireless communication and uses a wireless LAN to perform wireless LAN access. For this purpose, the communication module 220 can include multiple network interface cards, such as cellular communication interface cards 221 and 222 and an unlicensed frequency band communication interface card 223, either internally or externally. In the accompanying drawings, the communication module 220 is illustrated as a monolithic integrated module; however, unlike the drawings, each network interface card can be arranged independently depending on the circuit configuration or usage.

[0282] Cellular communication interface card 221 can transmit or receive radio signals with at least one of UE 100, external devices, and servers using a mobile communication network and provide cellular communication services in a first frequency band based on instructions from processor 210. According to an embodiment, cellular communication interface card 221 may include at least one NIC module using a frequency band less than 6 GHz. At least one NIC module of cellular communication interface card 221 can independently perform cellular communication with at least one of UE 100, external devices, and servers in accordance with cellular communication standards or protocols in a frequency band less than 6 GHz supported by the corresponding NIC module.

[0283] Cellular communication interface card 222 can transmit or receive radio signals with at least one of UE 100, external devices, and servers using a mobile communication network and provide cellular communication services in a second frequency band based on instructions from processor 210. According to an embodiment, cellular communication interface card 222 may include at least one NIC module using a 6 GHz or higher frequency band. At least one NIC module of cellular communication interface card 222 can independently perform cellular communication with at least one of UE 100, external devices, and servers in accordance with cellular communication standards or protocols in a 6 GHz or higher frequency band supported by the corresponding NIC module.

[0284] The unlicensed frequency band communication interface card 223 transmits or receives radio signals with at least one of the UE 100, external devices, and servers by using a third frequency band that is an unlicensed frequency band, and provides unlicensed frequency band communication services based on instructions from the processor 210. The unlicensed frequency band communication interface card 223 may include at least one NIC module using an unlicensed frequency band. For example, the unlicensed frequency band may be a 2.4 GHz or 5 GHz band. At least one NIC module of the unlicensed frequency band communication interface card 223 can independently or dependently perform wireless communication with at least one of the UE 100, external devices, and servers in accordance with the unlicensed frequency band communication standards or protocols of the frequency band supported by the corresponding NIC module.

[0285] ​ This is a block diagram illustrating a UE 100 and a base station 200 according to an embodiment of the present invention, and the blocks shown individually are logically divided elements of the device. Therefore, the aforementioned elements of the device can be installed in a single chip or multiple chips depending on the device design. Furthermore, a portion of the configuration of the UE 100, such as a user interface 140, a display unit 150, etc., may be selectively provided in the UE 100. Additionally, the user interface 140, display unit 150, etc., may be additionally provided in the base station 200 if necessary.

[0286] The embodiments of this disclosure can be implemented by various means. For example, the embodiments of this disclosure can be implemented by hardware, firmware, software, or a combination thereof.

[0287] When implemented in hardware, the methods according to embodiments of this disclosure can be implemented by one or more of the following: application-specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field-programmable gate arrays (FPGAs), processors, controllers, microcontrollers, and microprocessors.

[0288] When implemented via firmware or software, the methods according to embodiments of this disclosure can be implemented as modules, programs, or functions for performing the aforementioned functions or operations. Software code can be stored in memory and operated by a processor. The memory can be located inside or outside the processor and can exchange data with the processor through various previously known means.

[0289] ​ This is a flowchart of a method for a terminal to receive a downlink channel according to an embodiment of the present disclosure.

[0290] Reference ​ The terminal receives the description as shown in the reference. ​ The method for transmitting downlink channels from a base station.

[0291] The terminal can receive first information related to the guard band located in the first resource area of ​​a carrier from the base station (S2610).

[0292] The terminal can receive second information related to multiple resource sets from the base station, wherein each resource set is identified by a guard band in a first resource area based on the first information (S2620).

[0293] The terminal can receive the downlink channel from the base station on resources indicated by the second information as available for receiving the downlink channel (S2630).

[0294] Multiple resource sets can be configured using resources other than those allocated to the protected frequency band based on the first information.

[0295] The second information may be information indicating whether each of the multiple resource sets is available for downlink channel reception. The first information may be information related to whether the resources allocated for the guard band are available for downlink channel reception. When the resources allocated for the guard band are not available for downlink channel reception according to the first information, operation S2620 can be performed.

[0296] After operating S2610, the terminal can receive the Physical Downlink Control Channel (PDCCH) from the base station on a portion of multiple resource sets. Secondary information can be included in the downlink control information (DCI) of the PDCCH.

[0297] A DCI can be a group-common DCI. In other words, a DCI can be a format 2_0 DCI.

[0298] Additionally, after operating S2610, the terminal can receive information from the base station related to the second resource area received by the terminal monitoring PDCCH.

[0299] The second resource region may correspond to a portion of multiple resource sets, and the second resource region may include resources on which PDCCHs are received.

[0300] The second resource region may include the resources to which the control resource set (CORESET) is allocated.

[0301] The second piece of information can be in bitmap form indicating whether each of the multiple resource sets is available for transmission in the downlink channel.

[0302] The downlink channel operating S2630 can be at least one of the Physical Downlink Control Channel (PDCCH) and the Physical Downlink Shared Channel (PDSCH).

[0303] The first information and information related to the second resource area can be sent via higher-level signaling (e.g., RRC configuration).

[0304] A terminal that receives downlink channels from a base station can be configured to include a transceiver, a processor functionally connected to the transceiver, and a memory that stores instructions for operations to be performed by the processor and is connected to the processor.

[0305] The operations performed by the processor can be compared with the reference. ​ The operations described are the same.

[0306] Some embodiments may also be implemented in the form of a recording medium including computer-executable instructions, such as computer-executable program modules. Computer-readable media can be any available medium accessible to a computer and includes volatile and non-volatile media, removable and non-removable media. Furthermore, computer-readable media can include both computer storage media and communication media. Computer storage media includes volatile and non-volatile, removable and non-removable media implemented using any method or technology for storing information such as computer-readable instructions, data structures, program modules, or other data. Communication media typically include computer-readable instructions, data structures, other data in modulated data signals such as program modules, or other transmission mechanisms, and includes any information delivery medium.

[0307] The description of the invention above is merely exemplary, and those skilled in the art to which this invention pertains will understand that various modifications and changes can be made without altering the technical spirit or essential features of the invention. Therefore, it should be understood that the above embodiments are illustrative in all respects and not restrictive. For example, each component described as a single type can be implemented in a distributed manner, and similarly, components described as distributed can also be implemented in a composite manner.

[0308] The scope of this invention is indicated by the appended claims rather than the detailed description, and it should be interpreted that all changes or modifications derived from the meaning and scope of the claims and their equivalents are included within the scope of this invention.

Claims

1. A method used by a user equipment in a wireless communication system, the method comprising: Receive information related to the guard band for at least one of the uplink channel transmission and downlink channel reception; Receive downlink control information (DCI) including a bitmap. Each bit of the bitmap indicates whether each of one or more first subbands is available for downlink channel reception; Receive downlink channel on the first resource. Wherein, the first resource includes at least one subband of one or more first subbands of the channel available for the downlink as indicated by the bitmap, and the first resource does not include resources allocated for the first guard band based on information related to the guard band; and Transmit uplink channels on the second resource. The second resource includes one or more second sub-bands, and resources for the second protection band are allocated based on information related to the protection band.

2. The method according to claim 1, in, The second guard band is located between adjacent sub-bands in the frequency domain.

3. The method according to claim 1, in, The DCI is a group common DCIGC DCI.

4. The method according to claim 1, in, The information related to the protected frequency band is received via Radio Resource Control (RRC) signaling.

5. The method according to claim 1, in, Each of the one or more first sub-bands is a unit for channel access in unlicensed frequency bands.

6. A user equipment (UE) in a wireless communication system, the UE comprising, transceiver; as well as A processor, which is functionally connected to the transceiver, in, The processor is configured to: Receive information related to the guard band for at least one of the uplink channel transmission and downlink channel reception; Receive downlink control information (DCI) including a bitmap. Each bit of the bitmap indicates whether each of one or more first subbands is available for downlink channel reception; Receive downlink channel on the first resource. Wherein, the first resource includes at least one subband of one or more first subbands of the channel available for the downlink as indicated by the bitmap, and the first resource does not include resources allocated for the first guard band based on information related to the guard band; and Transmit uplink channels on the second resource. The second resource includes one or more second sub-bands, and resources for the second protection band are allocated based on information related to the protection band.

7. The UE according to claim 6, in, The second guard band is located between adjacent sub-bands in the frequency domain.

8. The UE according to claim 7, in, The DCI is a group common DCIGC DCI.

9. The UE according to claim 7, in, The information related to the protected frequency band is received via Radio Resource Control (RRC) signaling.

10. The UE according to claim 7, in, Each of the one or more first sub-bands is a unit for channel access in an unlicensed frequency band.

11. A method used by a base station in a wireless communication system, the method comprising: Transmit information related to the guard band of at least one of the uplink channel reception and downlink channel transmission; Send downlink control information (DCI) including a bitmap. Each bit of the bitmap indicates whether each of one or more first subbands is available for transmission in the downlink channel; Send downlink channels on the first resource. Wherein, the first resource includes at least one subband of one or more first subbands available for channel transmission in the downlink as indicated by the bitmap, and the first resource does not include resources allocated for the first guard band based on information related to the guard band; and Receive the uplink channel on the second resource. The second resource includes one or more second sub-bands, and resources for the second protection band are allocated based on information related to the protection band.

12. The method according to claim 11, in, The second guard band is located between adjacent sub-bands in the frequency domain.

13. The method according to claim 11, in, Each of the one or more first sub-bands is a unit for channel access in unlicensed frequency bands.

14. The method according to claim 11, in, The DCI is a group common DCIGC DCI.

15. The method according to claim 11, in, The information related to the protected frequency band is transmitted via Radio Resource Control (RRC) signaling.

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