Channel transmission and reception method using a guard band within one carrier in a wireless communication system and apparatus therefor

Abstract

To provide a method for receiving a downlink channel by a terminal in a wireless communication system.SOLUTION: The method includes: receiving, from a base station, first information related to a guard band in a first resource region located in one carrier; receiving, from the base station, second information related to multiple resource sets in the first resource region, each of which is distinguished by the guard band in the first resource region on the basis of the first information; and receiving, from the base station, a downlink channel on a resource indicated by the second information to be available for reception of the downlink channel.SELECTED DRAWING: Figure 26

Description

[Technical field]

[0001] The present specification relates to a wireless communication system, and to a channel transmission / reception method and device therefor using a guard band within one carrier. [Background technology]

[0002] Following the commercialization of 4G (4th generation) communication systems, efforts are being made to develop new 5G (5th generation) communication systems to meet the increasing demand for wireless data traffic. 5G communication systems are referred to as communication systems beyond 4G networks, systems beyond LTE systems, or new radio (NR) systems. In order to achieve high data transmission rates, 5G communication systems include systems operated using ultra-high frequency (mmWave) bands of 6 GHz or higher, and also include communication systems operated using frequency bands below 6 GHz in terms of ensuring coverage, and implementation in base stations and terminals is being considered.

[0003] The 3GPP (registered trademark) (3rd generation partnership project) NR system improves the efficiency of network spectrum, allowing carriers to provide more data and voice services with a given bandwidth. Thus, the 3GPP NR system is designed to meet the demand for high-speed data and media transmission in addition to supporting large capacity voice. The advantages of the NR system are that it has high throughput, low latency, frequency division duplex (FDD) and time division duplex (TDD) support on the same platform, improved end user environment, and low operating costs with a simple architecture.

[0004] For more efficient data processing, the dynamic TDD of the NR system uses a method of varying the number of OFDM (orthogoal frequency division multiplexing) symbols available for uplink and downlink depending on the data traffic direction of the user of the cell. For example, if the downlink traffic of a cell is greater than the uplink traffic, the base station allocates a number of downlink OFDM symbols to a slot (or subframe). Information regarding the slot configuration should be transmitted to the terminal.

[0005] To mitigate the path loss of radio waves in the ultra-high frequency band and increase the transmission distance of radio waves, beamforming, massive array multiple input / output (massive MIMO), full dimension multiple input / output (FD-MIMO), array antenna, analog beam-forming, hybrid beamforming that combines analog beamforming and digital beamforming, and large scale antenna technologies are being discussed for 5G communication systems. In addition, to improve the system network, technological developments are being conducted for the 5G communication system regarding advanced small cells, improved small cells, cloud radio access network (cloud RAN), ultra-dense networks, device to device communication (D2D), vehicle to everything communication (V2X), wireless backhaul, non-terrestrial network communication (NTN), moving networks, cooperative communication, coordinated multi-points (CoMP), and interference cancellation.In addition, advanced coding modulation (ACM) methods such as hybrid FSK and QAM modulation (FQAM) and sliding window superposition coding (SWSC), as well as advanced access technologies such as filter bank multi-carrier (FBMC), non-orthogonal multiple access (NOMA), and sparse code multiple access (SCMA) are being developed for 5G systems.

[0006] Meanwhile, the Internet is a human-centered network where humans generate and consume information, and is evolving into the Internet of Things (IoT) network that exchanges and processes information between distributed components such as objects. The Internet of Everything (IoE) technology is also emerging, which combines big data processing technology through connection with cloud servers with IoT technology. To realize IoT, technological elements such as sensing technology, wired and wireless communication and network infrastructure, service interface technology, and security technology are required, and recently, technologies such as sensor networks for connecting objects, machine to machine (M2M), and machine type communication (MTC) are being researched. In the IoT environment, intelligent IT (internet technology) services are provided that collect and analyze data generated from connected objects and create new value in human life. IoT is applied to fields such as smart homes, smart buildings, smart cities, smart cars or connected cars, smart grids, healthcare, smart home appliances, and advanced medical services through the fusion and integration of conventional IT technology and various industries.

[0007] Therefore, various attempts are being made to apply 5G communication systems to IoT networks. For example, technologies such as sensor networks, machine-to-machine, and MTC are being embodied by 5G communication technologies such as beamforming, MIMO, and array antennas. The application of cloud radio access network (cloud RAN), as the big data processing technology mentioned above, is also an example of the fusion of 5G technology and IoT technology. In general, mobile communication systems have been developed to provide voice services while ensuring user activity.

[0008] However, the mobile communication system has gradually expanded its service area from voice to data services, and is currently developed to the extent that it provides high-speed data services. However, due to the resource shortage phenomenon in the currently provided mobile communication system and the demand for high-speed services from users, a more advanced mobile communication system is required. The 3GPP NR system uses a dynamic time division duplex (TDD) scheme that can freely change the direction of OFDM symbols that make up a slot depending on the uplink and downlink traffic of a small cell. The base station transmits information about the slot configuration to the terminal to support dynamic TDD. However, there is a risk that the terminal cannot receive the slot configuration information or the terminal cannot operate due to the change in the slot configuration, so a method to improve this is required.

[0009] Recently, as mobile traffic has exploded due to the proliferation of smart devices, it has become difficult for traditional licensed frequency spectrum, or licensed frequency bands alone, to withstand the increasing data usage required to provide cellular communication services.

[0010] In this situation, the use of unlicensed frequency spectrum or unlicensed frequency bands (e.g., 2.4 GHz band, 5 GHz band, etc.) to provide cellular communication services is being discussed as a solution to the spectrum shortage problem.

[0011] Unlike licensed bands, where telecommunications carriers secure exclusive frequency usage rights through procedures such as auctions, unlicensed bands allow a large number of communication devices to be used simultaneously without restrictions, provided that they comply with a certain level of adjacent band protection regulations. Therefore, if unlicensed bands are used for cellular communication services, it will be difficult to guarantee the same level of communication quality as that provided by licensed bands, and there is a risk of interference problems occurring with wireless communication devices (e.g., wireless LAN devices) that have traditionally used unlicensed bands.

[0012] In order to use LTE and NR technologies in unlicensed bands, research should be conducted in advance on coexistence methods with existing unlicensed band devices and methods for efficiently sharing radio channels with other radio channels. In other words, a robust coexistence mechanism (RCM) needs to be developed so that devices using LTE and NR technologies in unlicensed bands do not affect existing unlicensed band devices. Summary of the Invention [Problem to be solved by the invention]

[0013] An object of the present specification is to provide a channel transmission / reception method and an apparatus therefor using a guard band within one carrier in a wireless communication system. [Means for solving the problem]

[0014] The present specification provides a method for receiving a downlink channel in a wireless communication system.

[0015] Specifically, the method performed by the terminal includes the steps of: receiving, from a base station, first information related to a guard band in a first resource region located in one carrier; receiving, from the base station, second information related to a plurality of resource sets separated by the guard band in the first resource region based on the first information; and receiving, from the base station, a downlink channel on resources indicated by the second information as available for receiving the downlink channel; wherein the plurality of resource sets are composed of resources other than resources allocated for the guard band based on the first information, and the second information is information indicating whether each of the plurality of resource sets is available for receiving the downlink channel.

[0016] In addition, in this specification, the method performed by the terminal further includes a step of receiving a Physical Downlink Control Channel (PDCCH) on some of the plurality of resource sets from the base station, and the second information is included in Downlink Control Information (DCI) of the PDCCH.

[0017] In addition, in this specification, the method performed by the terminal is characterized in that it further includes the step of receiving, from the base station, information regarding a second resource region that the terminal monitors for receiving the PDCCH.

[0018] A terminal for receiving a downlink channel in a wireless communication system, the terminal comprising: a transceiver; a processor; and a memory coupled to the processor, storing instructions for operations performed by the processor, the operations including: receiving, from a base station, first information related to a guard band in a first resource region located in one carrier; receiving, from the base station, second information related to a plurality of resource sets separated by the guard band in the first resource region based on the first information; and receiving, from the base station, a downlink channel on resources indicated by the second information as available for transmitting the downlink channel; the plurality of resource sets being configured with resources other than resources allocated for the guard band based on the first information, and the second information being information indicating whether each of the plurality of resource sets is available for receiving the downlink channel.

[0019] The operation may further include receiving a Physical Downlink Control Channel (PDCCH) from the base station on some of the plurality of resource sets, and the second information is included in Downlink Control Information (DCI) of the PDCCH.

[0020] The operation may further include receiving, from the base station, information regarding a second resource region that the terminal monitors for receiving the PDCCH.

[0021] In this specification, the DCI is characterized as being a group-common DCI.

[0022] In the present specification, the second resource region is a part of the plurality of resource sets, and the second resource region includes resources from which the PDCCH is received.

[0023] In this specification, the second resource region is characterized in that it is a resource to which a control resource set (CORESET) is assigned.

[0024] In the present specification, the second information indicates, in a bitmap format, whether each of the plurality of resource sets is available for the downlink channel transmission.

[0025] In the present specification, the downlink channel is at least one of a physical downlink control channel (PDCCH) and a physical downlink shared channel (PDSCH).

[0026] In this specification, the first information and the information regarding the second resource region are characterized in that they are transmitted by higher layer signaling.

[0027] Also in this specification, a method for transmitting a downlink in a wireless communication system, which is performed by a base station, includes a step of transmitting, to a terminal, first information related to a guard band in a first resource region located in one carrier; a step of transmitting, to the terminal, second information related to a plurality of resource sets divided by the guard band in the first resource region based on the first information; and a step of transmitting, to the terminal, a downlink channel on resources indicated by the second information as usable for the downlink channel transmission; wherein the plurality of resource sets are configured with resources other than resources allocated for the guard band based on the first information, and the second information is information indicating whether each of the plurality of resource sets is usable for the downlink channel transmission.

[0028] In the present specification, the second information indicates, in a bitmap format, whether each of the plurality of resource sets is available for the downlink channel transmission. Effect of the Invention

[0029] The present specification provides a method for setting resources for uplink channel and downlink channel transmission when a guard band exists within one carrier, and has an effect of enabling efficient channel transmission.

[0030] An embodiment of the present invention provides a method for efficiently transmitting and receiving physical channels and signals in a wireless communication system, and an apparatus using the same. The effects obtained from the present invention are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art to which the present invention pertains from the following description. [Brief description of the drawings]

[0031] [Figure 1] FIG. 2 is a diagram illustrating an example of a radio frame structure used in a wireless communication system. [Diagram 2] FIG. 1 is a diagram illustrating an example of a downlink (DL) / uplink (UL) slot structure in a wireless communication system. [Diagram 3] 1 is a diagram illustrating physical channels used in the 3GPP system and a general signal transmission method using the corresponding physical channels. [Figure 4] A diagram showing SS / PBCH blocks for initial cell access in a 3GPP NR system. [Diagram 5] A diagram showing a procedure for control information and control channel transmission in a 3GPP NR system. [Figure 6] FIG. 1 is a diagram showing a control resource set (CORESET) in which a physical downlink control channel (PDCCH) is transmitted in a 3GPP NR system. [Figure 7] A diagram showing a method for setting a PDCCH search space in a 3GPP NR system. [Figure 8] FIG. 1 is a conceptual diagram illustrating carrier aggregation. [Figure 9] FIG. 1 is a diagram for explaining single carrier communication and multi-carrier communication. [Figure 10] A diagram showing an example in which a cross-carrier scheduling technique is applied. [Figure 11] Illustrates a deployment scenario of a terminal and a base station in an LAA service environment. [Figure 12] The following are examples of existing communication methods that operate in unlicensed bands. [Figure 13] 1 illustrates a Listen-Before-Talk (LBT) process for DL ​​transmission. [Figure 14] 1 illustrates a Listen-Before-Talk (LBT) process for DL ​​transmission. [Figure 15] 1 illustrates DL transmission in an unlicensed band. [Figure 16]This example illustrates a method for adjusting the Contention Window Size (CWS) when accessing a channel in an unlicensed band. [Figure 17] This is an example of a method for configuring a BWP (BandWidth Part) having a bandwidth smaller than or equal to the bandwidth of a carrier (or cell) in a terminal in a 3GPP NR system. [Figure 18] In this example, when a terminal is assigned multiple BWPs, at least one CORESET is configured or assigned to the terminal in each BWP. [Figure 19] This shows that when a base station in an embodiment of the present invention configures a BWP to include one or more basic bandwidths, it transmits a PDCCH in a CORESET configured for each basic bandwidth based on the priority for each basic bandwidth, and transmits a PDSCH within the BWP. [Figure 20] This shows that when a BWP is configured to include one or more basic bandwidths according to an embodiment of the present invention, the base station transmits a PDCCH in a CORESET configured for each basic bandwidth according to the priority of the specified basic bandwidths, and transmits a PDSCH within the BWP. [Figure 21] This indicates that when a BWP is configured to include one or more basic bandwidths according to an embodiment of the present invention, one or more basic bandwidths in which a base station can transmit a PDCCH are specified, and the base station transmits a PDCCH in a CORESET set within each basic bandwidth according to the specified basic bandwidth, and transmits a PDSCH within the BWP. [Figure 22] FIG. 13 is a diagram showing an in-carrier guard band and a carrier guard band in a BWP composed of one or more LBT subbands on a wideband carrier. [Diagram 23] An embodiment of the number of physical resource blocks (RBs) that can be used consecutively when bandwidths of 20 MHz, 40 MHz, and 80 MHz are used as BWPs will be described below. [Figure 24]An embodiment of the number of physical RBs that can be used as in-carrier guard bands when bandwidths of 20 MHz, 40 MHz, and 80 MHz are used as BWPs is shown, and an embodiment of the number of physical RBs that can be used for each LBT subband by BWPs having bandwidths of 20 MHz, 40 MHz, and 80 MHz is shown. [Diagram 25] 2 is a block diagram showing the configuration of a terminal and a base station according to an embodiment of the present invention. [Figure 26] 5 is a flowchart illustrating a method for receiving a downlink channel performed by a terminal according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0032] The terms used in this specification are selected as common terms currently widely used as much as possible in consideration of the functions in the present invention, but this may vary depending on the intentions, customs, or the emergence of new technologies of the engineers in this field. In addition, in certain cases, the applicant may arbitrarily select some terms, and in this case, the meaning will be described in the description of the relevant invention. Therefore, it is clear that the terms used in this specification should be analyzed based on the substantial meaning of the terms and the contents of this specification as a whole, rather than simply the names of the terms.

[0033] Throughout the specification, when a certain component is "connected" to another component, this includes not only "direct connection" but also "electrical connection" through other components in between. Furthermore, when a certain component is "included" in a certain component, this does not mean excluding other components, but further includes other components, unless otherwise specified to the contrary. In addition, limitations such as "more than" or "less than" based on a specific threshold may be appropriately replaced with "more than" or "less than", respectively, depending on the embodiment.

[0034] The following technologies are 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), single carrier frequency division multiple access (SC-FDMA), etc. CDMA is implemented in radio technologies such as Universal Terrestrial Radio Access (UTRA) and CDMA2000. TDMA is implemented in radio technologies such as Global System for Mobile communications (GSM), General Packet Radio Service (GPRS), and Enhanced Data Rates for GSM Evolution (EDGE). OFDMA is implemented in radio technologies such as IEEE802.11 (Wi-Fi), IEEE802.16 (WiMAX), IEEE802-20, Evolved UTRA (E-UTRA), etc. UTRA is part of the Universal Mobile Telecommunication System (UMTS). 3GPP LTE (Long term evolution) is a part of E-UMTS (Evolved UMTS) using E-UTRA, and LTE-A (Advanced) is an evolved version of 3GPP LTE. 3GPP NR is a system designed separately from LTE / LTE-A, and is a system for supporting eMBB (enhanced Mobile BroadBand), URLLC (Ultra-Reliable and Low Latency Communication), and mMTC (massive Machine Type Communication) services, which are requirements of IMT-2020. For clarity of explanation, the following description will focus on 3GPP NR, but the technical idea of ​​the present invention is not limited thereto.

[0035] Unless otherwise specified in this specification, a base station may refer to a next generation node B (gNB) as specified in 3GPP NR. Furthermore, unless otherwise specified, a terminal may refer to a user equipment (UE). In the following, in order to facilitate understanding of the description, each content will be described separately as an embodiment, but each embodiment may be used in combination with each other. In this disclosure, the configuration of a terminal may represent a configuration by a base station. Specifically, a base station may transmit a channel or a signal to a terminal and configure the operation of the terminal or the value of a parameter used in a wireless communication system.

[0036] FIG. 1 is a diagram illustrating an example of a radio frame structure used in a wireless communication system.

[0037] Referring to FIG. 1, the radio frame used in the 3GPP NR system is 10 ms (Δf max N f / 100)*T c ) and the radio frame consists of 10 equally sized subframes (SF). Here, Δf max =480*103Hz, N f =4096, T c =1 / (Δf ref *N f,ref ), Δf ref =15*103Hz, N f,ref= 2048. The 10 subframes in one frame are numbered from 0 to 9. Each subframe has a length of 1 ms and consists of one or more slots depending on the subcarrier spacing. More specifically, the subcarrier spacing that can be used in the 3GPP NR system is 15*2μkHz. μ is the subcarrier spacing configuration, and μ has values ​​of 0 to 4. That is, 15 kHz, 30 kHz, 60 kHz, 120 kHz, or 240 kHz are used as the subcarrier spacing. A 1 ms long subframe has 2 slots. μ Each slot has a length of 2-μms. μ The slots range from 0 to 2 μ The slots in a radio frame are numbered from 0 to 10*2. μ The time resources are assigned numbers up to -1. The time resources are divided by at least one of a radio frame number (also called a radio frame index), a subframe number (also called a subframe index), and a slot number (or a slot index).

[0038] FIG2 illustrates an example of a downlink (DL) / uplink (UL) slot structure in a wireless communication system, and in particular, illustrates a resource grid structure in a 3GPP NR system.

[0039] Specifically, FIG. 2 shows the structure of a resource grid in a 3GPP NR system. There is one resource grid per antenna port. Referring to FIG. 2, a slot includes multiple orthogonal frequency division multiplexing (OFDM) symbols in the time domain and multiple resource blocks (RBs) in the frequency domain. An OFDM symbol also means one symbol section. Unless otherwise specified, an OFDM symbol may simply be referred to as a symbol. One RB includes 12 consecutive subcarriers in the frequency domain. Referring to FIG. 2, a signal transmitted from each slot may be represented by a resource grid including Nsize,μgrid,x*NRBsc subcarriers and Nslotsymb OFDM symbols, where x=DL when the signal is a DL signal and x=UL when the signal is a UL signal. Nsize,μgrid,x represents the number of resource blocks (RBs) according to the subcarrier spacing, which is a component of μ (x is DL or UL), and Nslotsymb represents the number of OFDM symbols in a slot. NRBsc is the number of subcarriers that make up one RB, and NRBsc = 12. Depending on the multiple access method, OFDM symbols may be called cyclic shift OFDM (CP-OFDM) symbols or discrete Fourier transform spread OFDM (DFT-s-OFDM) symbols.

[0040] The number of OFDM symbols included in one slot may vary according to the length of a cyclic prefix (CP). For example, in the case of a normal CP, one slot may include 14 OFDM symbols, while in the case of an extended CP, one slot may include 12 OFDM symbols. In a particular embodiment, the extended CP may be used only in a 60 kHz subcarrier spacing. In FIG. 2, for convenience of explanation, one slot is configured with 14 OFDM symbols as an example, but the embodiments of the present disclosure may be similarly applied to slots having different numbers of OFDM symbols. Referring to FIG. 2, each OFDM symbol is N size,μ grid,x *N RB sc The subcarrier type may be divided into data subcarriers for data transmission, reference signal subcarriers for the transmission of reference signals, and guard bands. The carrier frequency is also called the center frequency (fc).

[0041] One RB is N RB sc A RB may be defined by N (e.g., 12) consecutive subcarriers. For reference, a resource consisting of one OFDM symbol and one subcarrier may be referred to as a resource element (RE) or tone. Thus, one RB may be defined by N slot symb *N RB sc Each resource element in the resource grid may be uniquely defined in one slot by a pair of indices (k, l), where k ranges from 0 to N in the frequency domain. size,μ grid,x *N RB sc -1, and l is an index ranging from 0 to N in the time domain. slot symb It may be an index that scales down to -1.

[0042] In order for a UE to receive signals from or transmit signals to a base station, the time / frequency of the UE may be synchronized to the time / frequency of the base station, since when the base station and the UE are synchronized, the UE can determine the necessary time and frequency parameters to demodulate DL signals and transmit UL signals at the appropriate time.

[0043] Each symbol of a radio frame used in time division duplex (TDD), i.e., unpaired spectrum, may be configured with at least one of DL symbols, UL symbols, and flexible symbols. A radio frame used as a DL carrier in frequency division duplex (FDD), i.e., paired spectrum, may be configured with DL symbols or flexible symbols, and a radio frame used as a UL carrier may be configured with UL symbols or flexible symbols. A DL symbol allows DL transmission but not UL transmission. A UL symbol allows UL transmission but not DL transmission. A flexible symbol may be determined to be used as DL or UL according to a signal.

[0044] Information about the type of each symbol, i.e., information representing any one of DL symbols, UL symbols, and flexible symbols, can be configured using cell-specific or common radio resource control (RRC) signals. Additionally, information about the type of each symbol can be configured additionally using UE-specific or dedicated RRC signals. The base station notifies, by using the cell-specific RRC signal, i) the period of the cell-specific slot configuration, ii) the number of slots with only DL symbols from the beginning of the period of the cell-specific slot configuration, iii) the number of DL symbols from the first symbol of the slot immediately following the slot with only DL symbols, iv) the number of slots with only UL symbols from the end of the period of the cell-specific slot configuration, and v) the number of UL symbols from the last symbol of the slot immediately preceding the slot with only UL symbols. Here, a symbol that is not configured using either UL symbols or DL symbols is a flexible symbol.

[0045] When information about the symbol type is configured using the UE-specific RRC signal, the base station can signal in the cell-specific RRC signal whether the flexible symbol is a DL symbol or a UL symbol. In this case, the UE-specific RRC signal cannot change a DL symbol or a UL symbol configured using the cell-specific RRC signal to another symbol type. The UE-specific RRC signal can signal the number of DL symbols among the Nslotsymb symbols of the corresponding slot for each slot, and the number of UL symbols among the Nslotsymb symbols of the corresponding slot. In this case, the DL symbols of the slot can be continuously configured using the first symbol to the i-th symbol of the slot. Additionally, the UL symbols of the slot can be continuously configured using the j-th symbol to the last symbol of the slot (where i < j). Among the slots, a symbol that is not configured using either UL symbols or DL symbols is a flexible symbol.

[0046] The type of symbols consisting of the RRC signal is called a semi-static DL / UL configuration. In the semi-static DL / UL configuration consisting of the RRC signal, the flexible symbol is designated as a downlink symbol, an uplink symbol, or a flexible symbol through dynamic slot format information (SFI) transmitted on a physical downlink control channel (PDCCH). In this case, the downlink symbol or the uplink symbol consisting of the RRC signal is not changed to another symbol type. Table 1 shows an example of dynamic SFI designated by the base station to the terminal.

[0047] [Table 1]

[0048] In Table 1, D indicates a downlink symbol, U indicates an uplink symbol, and X indicates a flexible symbol. As shown in Table 1, up to two DL / UL switchings are allowed in one slot.

[0049] FIG. 3 is a diagram illustrating physical channels used in a 3GPP system (e.g., NR) and a general signal transmission method using the physical channels.

[0050] When the UE is powered on or camps on a new cell, the UE performs an initial cell search (S101). Specifically, the UE may synchronize to a BS during the initial cell search. For this, the UE may receive a primary synchronization signal (PSS) and a secondary synchronization signal (SSS) from a base station to synchronize to the base station and obtain information such as a cell ID. After that, the UE may receive a physical broadcast channel from the base station and obtain broadcast information in the cell.

[0051] Upon completion of the initial cell search, the UE receives a physical downlink shared channel (PDSCH) according to a physical downlink control channel (PDCCH) and information in the PDCCH, so that the UE can acquire system information that is more specific than the system information acquired through the initial cell search (S102). Here, the system information acquired by the UE is cell-common system information for the UE to operate correctly in a physical layer in a Radio Resource Control (RRC), and is also called remaining system information or system information block (SIB) 1.

[0052] When the UE first accesses a base station or does not have radio resources for signal transmission, the UE may perform a random access procedure to the base station (operations S103 to S106). First, the UE may transmit a preamble through a physical random access channel (PRACH) (S103) and may receive a response message to the preamble from the base station through a PDCCH and a corresponding PDSCH (S104). When a valid random access response message is received by the UE, the UE transmits data including the UE's identifier and the like to the base station through a physical uplink shared channel (PUSCH) indicated by a UL grant transmitted from the base station through the PDCCH (S105). Next, the UE waits to receive a PDCCH as an indication of the base station for collision resolution. If the UE successfully receives the PDCCH through the UE's identifier (S106), the random access process is terminated. During the random access process, the UE may obtain UE-specific system information required for the UE to operate correctly at the physical layer in the RRC layer. Once the UE has acquired UE-specific system information at the RRC layer, the UE enters the RRC connected mode (RRC_CONNECTED mode).

[0053] The RRC layer is used to generate and manage messages for control between a terminal and a radio access network (RAN). More specifically, the base station and the terminal can perform storage management including broadcasting of cell system information required for all terminals in a cell, delivery management of paging messages, mobility management and handover, terminal measurement reports and control therefor, terminal capability management, and device management in the RRC layer. In general, an update of a signal transmitted in the RRC layer (hereinafter, an RRC signal) is longer than a transmission / reception period (i.e., a transmission time interval, TTI) in the physical layer, so that the RRC signal can be maintained unchanged for a long period.

[0054] After the above-described procedure, the UE receives the PDCCH / PDSCH (S107) and transmits the physical uplink shared channel (PUSCH) / physical uplink control channel (PUCCH) as a general UL / DL signal transmission procedure (S108). Specifically, the UE may receive downlink control information (DCI) through the PDCCH. The DCI may include control information such as resource allocation information for the UE. The format of the DCI may also vary depending on the intended use. The uplink control information (UCI) that the UE transmits to the base station through the UL includes DL / UL ACK / NACK signals, a channel quality indicator (CQI), a precoding matrix index (PMI), a rank indicator (RI), etc. Here, the CQI, PMI, and RI may be included in the channel state information (CSI). In a 3GPP NR system, the UE may transmit control information, such as HARQ-ACK and CSI, described above, via the PUSCH and / or PUCCH.

[0055] FIG. 4 shows an SS / PBCH block for initial cell access in a 3GPP NR system.

[0056] When powered on or when wanting to access a new cell, the UE may obtain time and frequency synchronization with the cell and perform an initial cell search procedure. The UE may detect the physical cell identity NcellID of the cell during the cell search procedure. For this, the UE may receive synchronization signals, such as a primary synchronization signal (PSS) and a secondary synchronization signal (SSS), from the base station and may synchronize to the base station. In this case, the UE may obtain information such as a cell identity (ID).

[0057] With reference to FIG. 4a, the synchronization signal (SS) will be described in more detail. The synchronization signal may be classified into PSS and SSS. The PSS may be used to obtain time domain synchronization and / or frequency domain synchronization, such as OFDM symbol synchronization and slot synchronization. The SSS may be used to obtain frame synchronization and cell group ID. With reference to FIG. 4a and Table 1, the SS / PBCH block may be configured using 20 consecutive RBs (=240 subcarriers) in the frequency axis and may be configured using 4 consecutive OFDM symbols in the time axis. In this case, in the SS / PBCH block, the PSS is transmitted in the first OFDM symbol, and the SSS is transmitted in the third OFDM symbol through the 56th to 182nd subcarriers. Here, the smallest subcarrier index of the SS / PBCH block is numbered from 0. In the first OFDM symbol in which the PSS is transmitted, the base station does not transmit signals through the remaining subcarriers, i.e., subcarriers 0 to 55 and 183 to 239. In addition, in the third OFDM symbol in which the SSS is transmitted, the base station does not transmit signals through subcarriers 48 to 55 and 183 to 191. The base station transmits a physical broadcast channel (PBCH) through the remaining REs in the SS / PBCH block excluding the above signals.

[0058] [Table 2]

[0059] The SS allows a total of 1008 unique physical layer cell IDs to be grouped into 336 physical layer cell identifier groups, each group specifically including three unique identifiers through a combination of three PSSs and SSSs such that each physical layer cell ID is only part of one physical layer cell identifier group. Thus, a physical layer cell ID NcellID=3N(1)ID+N(2)ID can be uniquely defined by an index N(1)ID ranging from 0 to 335 indicating a physical layer cell identifier group, and an index N(2)ID ranging from 0 to 2 indicating a physical layer identifier in the physical layer cell identifier group. The UE can detect the PSS and identify one of the three unique physical layer identifiers. In addition, the UE can detect the SSS and identify one of the 336 physical layer cell IDs associated with the physical layer identifiers. In this case, the sequence of PSSs dPSS(n) is as follows:

[0060]

number

[0061] Furthermore, the sequence of SSSs dSSS(n) is as follows:

number

[0062] A radio frame with a length of 10 ms may be divided into two half frames with a length of 5 ms. With reference to FIG. 4b, a description of the slots in which the SS / PBCH block is transmitted in each half frame is provided. The slot in which the SS / PBCH block is transmitted may be any one of cases A, B, C, D, and E. In case A, the subcarrier spacing is 15 kHz, and the start of the SS / PBCH block is the ({2,8}+14*n)th symbol. In this case, n=0 or 1 for carrier frequencies below 3 GHz. Additionally, n=0,1,2,3 may be used for carrier frequencies above 3 GHz and below 6 GHz. In case B, the subcarrier spacing is 30 kHz, and the start of the SS / PBCH block is {4,8,16,20}+28*n. In this case, n=0 for carrier frequencies below 3 GHz. Additionally, n=0,1 may be used for carrier frequencies above 3 GHz and below 6 GHz. In case C, the subcarrier spacing is 30 kHz and the start of the SS / PBCH block is the ({2,8}+14*n)th symbol, where n=0 or 1 for carrier frequencies below 3 GHz. Additionally, n=0,1,2,3 for carrier frequencies above 3 GHz and below 6 GHz. In case D, the subcarrier spacing is 120 kHz and the start of the SS / PBCH block is the ({4,8,16,20}+28*n)th symbol, where n=0,1,2,3,5,6,7,8,10,11,12,13,15,16,17,18 for carrier frequencies above 6 GHz. In case E, the subcarrier spacing is 240 kHz and the start of the SS / PBCH block is the ({8,12,16,20,32,36,40,44}+56*n)th symbol. In this case, n=0,1,2,3,5,6,7,8 for carrier frequencies above 6GHz.

[0063] Figure 5 shows a procedure for transmitting control information and control channels in a 3GPP NR system. Referring to Figure 5a, a base station may add a cyclic redundancy check (CRC) masked (e.g., XORed) with a radio network temporary identifier (RNTI) to the control information (e.g., downlink control information (DCI)) (S202). The base station may scramble the CRC with an RNTI value determined according to the purpose / target of each control information. The common RNTI used by one or more UEs may include at least one of a system information RNTI (SI-RNTI), a paging RNTI (P-RNTI), a random access RNTI (RA-RNTI), and a transmit power control RNTI (TPC-RNTI). In addition, the UE-specific RNTI may include at least one of a cell temporary RNTI (C-RNTI) and a CS-RNTI. Then, the base station may perform rate matching according to the amount of resources used for PDCCH transmission after performing channel coding (e.g., polar coding) (S204). Then, the base station may multiplex DCI based on a control channel element (CCE)-based PDCCH structure (S208). In addition, the base station may apply additional processes such as scrambling, modulation (e.g., QPSK), interleaving, etc. to the multiplexed DCI (S210), and then map the DCI to resources to be transmitted. A CCE is a basic resource unit for a PDCCH, and one CCE may include multiple (e.g., 6) resource element groups (REGs). One REG may be configured with multiple (e.g., 12) REs. The number of CCEs used for one PDCCH may be defined as an aggregation level.In a 3GPP NR system, aggregation levels of 1, 2, 4, 8, or 16 may be used. Figure 5b is a diagram relating to CCE aggregation levels and PDCCH multiplexing, showing the type of CCE aggregation level used for one PDCCH and the CCEs transmitted in the control area accordingly.

[0064] FIG. 6 illustrates a control resource set (core set) in which a physical downlink control channel (PDCCH) may be transmitted in a 3GPP NR system.

[0065] A core set is a time-frequency resource in which the PDCCH, i.e., the control signal for the UE, is transmitted. In addition, a search space, which will be described later, may be mapped to one core set. Thus, instead of monitoring all frequency bands for PDCCH reception, the UE may monitor a time-frequency region designated as a core set and decode the PDCCH mapped to the core set. The base station may configure one or more core sets per cell for the UE. A core set may be configured with up to three consecutive symbols on the time axis. In addition, a core set may be configured in units of six consecutive PRBs on the frequency axis. In the embodiment of FIG. 6, core set #1 is configured with consecutive PRBs, and core set #2 and core set #3 are configured with non-consecutive PRBs. A core set may be located in any symbol in a slot. For example, in the embodiment of FIG. 6, core set #1 starts in the first symbol of the slot, core set #2 starts in the fifth symbol of the slot, and core set #9 starts in the ninth symbol of the slot.

[0066] FIG. 7 illustrates a method for configuring a PUCCH search space in a 3GPP NR system.

[0067] To transmit the PDCCH to the UE, each core set may have at least one search space. In an embodiment of the present disclosure, the search space is a set of all time-frequency resources through which the PDCCH of the UE can be transmitted (hereinafter, PDCCH candidates). The search space may include a common search space that 3GPP NR UEs are required to search in common, and a terminal-specific or UE-specific search space that a specific UE is required to search. In the common search space, the UE may monitor the PDCCH that all UEs in a cell belonging to the same base station are set to search in common. In addition, a UE-specific search space may be configured for each UE, such that the UE monitors the PDCCH allocated to each UE at different search space positions according to the UE. In the case of the UE-specific search space, the search spaces between UEs may be partially overlapped and allocated due to the limited control area in which the PDCCH is allocated. Monitoring the PDCCH includes blind decoding for PDCCH candidates in the search space. When blind decoding is successful, it may be expressed that the PDCCH is (successfully) detected / received, and when blind decoding fails, it may be expressed that the PDCCH is not detected / received or is not successfully detected / received.

[0068] For ease of description, 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 referred to as a group common (GC) PDCCH or a common PDCCH. In addition, a PDCCH scrambled with a terminal-specific RNTI already known by a particular UE to transmit UL or DL ​​scheduling information to the particular UE is referred to as a UE-specific PDCCH. The common PDCCH may be included in a common search space, and the UE-specific PDCCH may be included in a common search space or a UE-specific PDCCH.

[0069] The base station may signal to each UE or a group of UEs via the PDCCH about information related to resource allocation of the transmission channels paging channel (PCH) and downlink shared channel (DL-SCH) (i.e., DL grants), or information related to resource allocation of the uplink shared channel (UL-SCH) and hybrid automatic repeat request (HARQ) (i.e., UL grants). The base station may transmit the PCH transport block and the DL-SCH transport block via the PDSCH. The base station may transmit data, except for specific control information or specific service data, via the PDSCH. In addition, the UE may receive data, except for specific control information or specific service data, via the PDSCH.

[0070] A base station may include in a PDCCH information about where the PDSCH data is transmitted to a UE (one or more UEs) and how the PDSCH data is to be received and decoded by the corresponding UE, and may transmit the PDCCH. For example, assume that the DCI transmitted on a certain PDCCH is CRC masked with an RNTI of "A", and the DCI indicates that the PDSCH is allocated to a radio resource (e.g., a frequency location) of "B", and indicates transmission format information (e.g., transport block size, modulation scheme, coding information, etc.) of "C". The UE monitors the PDCCH using the RNTI information that the UE has. In this case, if a UE performs blind decoding of the PDCCH using the RNTI of "A", the UE receives the PDCCH and receives the PDSCH indicated by "B" and "C" through the received PDCCH information.

[0071] Table 3 illustrates one embodiment of a physical uplink control channel (PUCCH) for use in a wireless communication system.

[0072] [Table 3]

[0073] The PUCCH may be used to transmit the following UL control information (UCI):

[0074] -Scheduling Request (SR): Information used to request UL UL-SCH resources.

[0075] -HARQ-ACK: A response to the PDCCH (indicating DL SPS release) and / or a response to a DL transport block (TB) on the PDSCH. The HARQ-ACK indicates whether information transmitted on the PDCCH or PDSCH has been received. The HARQ-ACK response includes a positive ACK (simply ACK), a negative ACK (hereinafter NACK), a discontinuous transmission (DTX), or a NACK / DTX. Here, the term HARQ-ACK is used in conjunction with HARQ-ACK / NACK and ACK / NACK. In general, an ACK may be represented by a bit value of 1 and a NACK may be represented by a bit value of 0.

[0076] -Channel State Information (CSI): Feedback information on the DL channel. The UE generates it based on the CSI reference signal (RS) transmitted by the base station. Multiple-input multiple-output (MIMO) related feedback information includes a rank indicator (RI) and a precoding matrix indicator (PMI). The CSI may be divided into CSI part 1 and CSI part 2 according to the information indicated by the CSI.

[0077] In the 3GPP NR system, five PUCCH formats may be used to support different service scenarios, different channel environments, and frame structures.

[0078] PUCCH format 0 is a format capable of transmitting 1-bit or 2-bit HARQ-ACK information or SR. PUCCH format 0 can be transmitted through one or two OFDM symbols on the time axis and one RB on the frequency axis. When PUCCH format 0 is transmitted in two OFDM symbols, the same sequence on the two symbols may be transmitted through different RBs. In this case, the sequence may be a cyclic shift (CS) sequence from a base sequence used in PUCCH format 0. Through this, the UE can obtain frequency diversity gain. Specifically, the terminal can determine a cyclic shift (CS) value mcs according to Mbit bit UCI (Mbit=1 or 2). In addition, a cyclic shift sequence of a length 12 can be mapped to 12 REs of one OFDM symbol and one RB based on a determined CS value mcs and transmitted. If the number of cyclic shifts available to a terminal is 12 and Mbit=1, then the 1-bit UCI 0 and 1 may be mapped to two cyclic shifted sequences whose cyclic shift value difference is 6, and if Mbit=2, then the 2-bit UCI 00, 01, 11, and 10 may be mapped to four cyclic shifted sequences whose cyclic shift value difference is 3, respectively.

[0079] PUCCH format 1 transmits 1-bit or 2-bit HARQ-ACK information or SR. PUCCH format 1 is transmitted through continuous OFDM symbols on the time axis and one PRB on the frequency axis. Here, the number of OFDM symbols occupied by PUCCH format 1 is one of 4 to 14. More specifically, UCI with Mbit=1 is modulated by BPSK. The terminal modulates UCI with Mbit=2 by quadrature phase shift keying (QPSK). A signal is obtained by multiplying the modulated complex valued symbol d(0) by a sequence of length 12. The terminal transmits the obtained signal by spreading it by a time-axis orthogonal cover code (OCC) on even-numbered OFDM symbols to which PUCCH format 1 is assigned. In PUCCH format 1, the maximum number of different terminals multiplexed in the same RB can be determined according to the length of the OCC used. In odd-numbered OFDM symbols of PUCCH format 1, a demodulation reference signal (DMRS) is spread by OCC and mapped.

[0080] PUCCH format 2 may deliver more than two bits of UCI. PUCCH format 2 may be transmitted over one or two OFDM symbols on the time axis and one or more RBs on the frequency axis. When PUCCH format 2 is transmitted in two OFDM symbols, the sequences transmitted in different RBs over the two OFDM symbols may be identical to each other. Here, the sequence is a set of modulated complex-valued symbols d(0),...,d(M symbol -1), where M symbol is M bit / 2. Through this, the UE may obtain frequency diversity gain. More specifically, M bit Bit UCI(M bit>2) is bit-level scrambled, QPSK modulated, and mapped to RBs of one or two OFDM symbols, where the number of RBs may be one of 1 to 16.

[0081] PUCCH format 3 or PUCCH format 4 may deliver UCI that is greater than 2 bits. PUCCH format 3 or PUCCH format 4 may be transmitted over 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 may be one of 4 to 14. Specifically, the UE may transmit the UCI using π / 2-2 phase shift keying (BPSK) or QPSK. bit The complex-valued symbols d(0) to d(M symb -1), where M symb =M bit When using QPSK, M symb =M bit / 2. The UE may not apply block-wise spreading to PUCCH format 3. However, the UE may apply block-wise spreading to one RB (i.e., 12 subcarriers) using PreDFT-OCC with length 12, such that PUCCH format 4 may have a multiplexing capacity of 2 or 4. The UE performs transmit precoding (or DFT precoding) on ​​the spread signal and maps it to each RE to transmit the spread signal.

[0082] In this case, the number of RBs occupied by PUCCH format 2, PUCCH format 3, or PUCCH format 4 may be determined according to the length and maximum code rate of the UCI transmitted by the UE. When the UE uses PUCCH format 2, the UE may transmit HARQ-ACK information and CSI information together through the PUCCH. When the number of RBs that the UE may transmit is greater than the maximum number of RBs that PUCCH format 2, or PUCCH format 3, or PUCCH format 4 may use, the UE may transmit only the remaining UCI information without transmitting some UCI information according to the priority of the UCI information.

[0083] PUCCH format 1, PUCCH format 3, or PUCCH format 4 may be configured through RRC signaling to indicate frequency hopping within a slot. When frequency hopping is configured, an index of the RB to be frequency hopped may be configured using RRC signaling. When PUCCH format 1, PUCCH format 3, or PUCCH format 4 is transmitted over N OFDM symbols on the time axis, the first hop may have floor(N / 2) OFDM symbols and the second hop may have ceil(N / 2) OFDM symbols.

[0084] PUCCH format 1, PUCCH format 3, or PUCCH format 4 may be configured to be repeatedly transmitted in multiple slots. In this case, the number K of slots in which the PUCCH is repeatedly transmitted may be configured by RRC signaling. The repeatedly transmitted PUCCH must start at a fixed OFDM symbol in each slot and must have a constant length. When one of the OFDM symbols of a slot in which the UE should transmit the PUCCH is indicated as a DL symbol by RRC signaling, the UE may not transmit the PUCCH in the corresponding slot and may delay the transmission of the PUCCH until the next slot for transmitting the PUCCH.

[0085] Meanwhile, in a 3GPP NR system, a terminal can transmit and receive using a bandwidth smaller than or equal to the bandwidth of a carrier (or cell). To this end, the terminal may be configured with a BWP (bandwidth part) consisting of a continuous bandwidth of a part of the bandwidth of the carrier. A terminal operating according to TDD or in an unpaired spectrum may be configured with up to four DL / UL BWP pairs in one carrier (or cell). Also, the terminal may activate one DL / UL BWP pair. A terminal operating according to FDD or in a paired spectrum may be configured with up to four DL BWPs in a downlink carrier (or cell) and up to four UL BWPs in an uplink carrier (or cell). The terminal may activate one DL BWP and one UL BWP for each carrier (or cell). The terminal does not need to receive or transmit in time-frequency resources other than the activated BWP. An activated BWP may be referred to as an active BWP.

[0086] The base station may indicate to the terminal, by downlink control information (DCI), which BWP is activated among the configured BWPs. The BWP indicated by the DCI is activated, and the other configured BWPs are deactivated. In a carrier (or cell) operating in TDD, the base station may include a BPI (bandwidth part indicator) indicating the activated BWP in the DCI for scheduling the PDSCH or PUSCH to change the DL / UL BWP pair of the terminal. The terminal may receive the DCI for scheduling the PDSCH or PUSCH and identify the activated DL / UL BWP pair based on the BPI. In a downlink carrier (or cell) operating in FDD, the base station may include a BPI indicating the activated BWP in the DCI for scheduling the PDSCH to change the DL BWP of the terminal. In the case of an uplink carrier (or cell) operating in FDD, the base station may include a BPI indicating the activated BWP in the DCI for scheduling the PUSCH to change the UL BWP of the terminal.

[0087] FIG. 8 is a conceptual diagram illustrating carrier aggregation.

[0088] Carrier aggregation is a method in which a UE uses multiple frequency blocks or cells (in a logical sense) configured with UL resources (or component carriers) and / or DL ​​resources (or component carriers) as one large logical frequency band so that a wireless communication system can use a wider frequency band. One component carrier may be called a primary cell (PCell) or a secondary cell (SCell), or a primary SCell (PScell). However, in the following, for convenience of explanation, the term "component carrier" is used.

[0089] Referring to Figure 8, as an example of a 3GPP NR system, the overall system band may include up to 16 component carriers, and each component carrier may have a bandwidth of up to 400 MHz. A component carrier may include one or more physically contiguous subcarriers. Although each of the component carriers is shown in Figure 8 to have the same bandwidth, this is only an example and each component carrier may have a different bandwidth. Also, although each component carrier is shown as adjacent to each other in the frequency axis, the drawing is shown in a logical concept and each component carrier may be physically adjacent to each other or spaced apart.

[0090] A different center frequency may be used for each component carrier. Also, one common center frequency may be used for physically adjacent component carriers. In the embodiment of FIG. 8, assuming that all component carriers are physically adjacent, center frequency A may be used for all component carriers. Furthermore, assuming that the respective component carriers are not physically adjacent to each other, center frequency A and center frequency B may be used for each of the component carriers.

[0091] When the entire system band is expanded by carrier aggregation, the frequency band used for communication with each UE may be specified in units of component carriers. UE A may use 100 MHz, which is the entire system band, and perform communication using all five component carriers. UEs B1 to B5 may use only a 20 MHz bandwidth and perform communication using one component carrier. UEs C1 and C2 may use a 40 MHz bandwidth and each perform communication using two component carriers. The example of FIG. 8 shows a case where UE C1 uses two non-adjacent component carriers and UE C2 uses two adjacent component carriers.

[0092] 9 is a diagram for explaining single carrier communication and multiple carrier communication. Specifically, FIG. 9(a) shows a single carrier subframe structure, and FIG. 9(b) shows a multi-carrier subframe structure.

[0093] With reference to FIG. 9(a), in an FDD mode, a typical wireless communication system may perform data transmission or data reception through one DL band and one UL band corresponding thereto. In another specific embodiment, in a TDD mode, a wireless communication system may divide a radio frame into UL time units and DL time units in the time domain, and may perform data transmission or data reception through the UL / DL time units. With reference to FIG. 9(b), three 20 MHz component carriers (CCs) may be aggregated into each of the UL and DL such that a bandwidth of 60 MHz may be supported. Each CC may or may not be adjacent to each other in the frequency domain. Although FIG. 9(b) shows a case where the bandwidth of the UL CC and the bandwidth of the DL CC are the same and symmetrical, the bandwidth of each CC may be determined independently. In addition, asymmetric carrier aggregation with different numbers of UL CCs and DL CCs is possible. A DL / UL CC allocated / configured to a particular UE through RRC may be referred to as a serving DL / UL CC of the particular UE.

[0094] A base station may perform communication with a UE by activating some or all of the serving CCs of the UE, or by deactivating some CCs. The base station may change the CCs to be activated / deactivated, and may 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 may be deactivated unless the CC allocation for the UE is completely reconfigured or the UE is handed over. The one CC that is not deactivated by the UE is called a Primary CC (PCC) or a Primary Cell (PCell), and the CC that the base station can activate / deactivate freely is called a Secondary CC (SCC) or a Secondary Cell (SCell).

[0095] On the other hand, 3GPP NR uses the concept that a cell manages radio resources. A cell is defined as a combination of DL and UL resources, i.e., a combination of DL CC and UL CC. A cell may be configured with only DL resources or a combination of DL and UL resources. When carrier aggregation is supported, the association between the carrier frequency of DL resources (i.e., DL CC) and the carrier frequency of UL resources (i.e., UL CC) may be indicated by the system information. Carrier frequency refers to the center frequency of each cell or CC. A cell corresponding to a PCC is called a PCell, and a cell corresponding to a SCC is called a SCell. A carrier corresponding to a PCell in DL is a DL PCC, and a carrier corresponding to a PCell in UL is a UL PCC. Similarly, a carrier corresponding to a SCell in DL is a DL SCC, and a carrier corresponding to a SCell in UL is a UL SCC. According to the UE capabilities, a serving cell may be configured with one PCell and zero or more SCells. For a UE that is in RRC_CONNECTED state but is not configured for or does not support carrier aggregation, there is only one serving cell configured with only a PCell.

[0096] As mentioned above, the term "cell" used in carrier aggregation is distinguished from the term "cell" referring to several geographical areas where communication services are provided by one base station or one antenna group. That is, one component carrier may also be called a scheduling cell, a scheduled cell, a primary cell (PCell), a secondary cell (SCell), or a primary SCell (PScell). However, in order to distinguish between a cell referring to several geographical areas and a cell of carrier aggregation, in this disclosure, a cell of carrier aggregation is called a CC, and a cell of a geographical area is called a cell.

[0097] FIG. 10 illustrates an example in which a cross-carrier scheduling technique is applied. When cross-carrier scheduling is configured, a control channel transmitted through a first CC may schedule a data channel transmitted through a first CC or a second CC using a carrier indicator field (CIF). The CIF is included in the DCI. In other words, a scheduling cell is configured, and a DL grant / UL grant transmitted in the PDCCH area of ​​the scheduling cell schedules the PDSCH / PUSCH of the scheduled cell. That is, a search area for multiple component carriers exists in the PDCCH area of ​​the scheduling cell. A PCell may be essentially a scheduling cell, and a specific SCell may be designated as a scheduling cell by higher layers.

[0098] In the embodiment of FIG. 10, it is assumed that three DL CCs are merged. Here, it is assumed that DL component carrier #0 is a DL PCC (or PCell), and DL component carrier #1 and DL component carrier #2 are DL SCCs (or SCells). In addition, it is assumed that the DL PCC is configured to the PDCCH monitoring CC. When cross-carrier scheduling is not configured by UE-specific (or UE group-specific or cell-specific) higher layer signaling, the CIF is disabled, and each DL CC can only transmit a PDCCH for scheduling its PDSCH without a CIF according to the NR PDCCH rules (non-cross-carrier scheduling, self-carrier scheduling). On the other hand, when cross-carrier scheduling is configured by UE-specific (or UE group-specific or cell-specific) higher layer signaling, the CIF is enabled, and a certain CC (e.g., DL PCC) may transmit not only a PDCCH for scheduling a PDSCH of DL CC A using the CIF, but also a PDCCH for scheduling a PDSCH of another CC (cross-carrier scheduling). On the other hand, the PDCCH is not transmitted in another DL CC. Thus, the UE monitors either the PDCCH without a CIF to receive a self-carrier scheduled PDSCH or the PDCCH with a CIF to receive a cross-carrier scheduled PDSCH, depending on whether cross-carrier scheduling is configured for the UE.

[0099] On the other hand, Figures 9 and 10 show the subframe structure of a 3GPP LTE-A system, and the same or similar configuration may be applied to a 3GPP NR system, except that in a 3GPP NR system, the subframes in Figures 9 and 10 may be replaced with slots.

[0100] In addition, unlike 3GPP LTE(-A), the NR system uses CBG (Code Block Group)-based transmission. The following is a related explanation.

[0101] In 3GPP LTE(-A), a TB (Transport Block), which is a unit transmitted in a PDSCH, is attached with a TB-CRC (Cyclic Redundancy Code) for detecting TB errors, and is divided into multiple CBs (Code Blocks) for channel coding efficiency. Each CB is attached with a CB-CRC (Cyclic Redundancy Code) for detecting CB errors. When receiving a PDSCH, a terminal transmits an ACK if it does not detect an error in the TB-CRC, and transmits a NACK if it detects an error in the TB-CRC. That is, one HARQ-ACK is transmitted per TB. When a base station receives a NACK, it determines that an error occurred in the previous TB, and performs HARQ retransmission of all CBs included in the TB. Therefore, in an LTE system, if any one of the CBs is received erroneously, all CBs included in the TB are retransmitted, increasing the possibility of inefficient retransmission. To solve this problem, in the NR system, a method has been introduced in which CBs constituting TBs are collected to form CBGs (Code Block Groups) and configured to transmit HARQ-ACK on a CBG basis, thereby informing the base station of the success or failure of reception for each CBG in downlink transmission as CBG level HARQ-ACK feedback, and the base station retransmits only the CBGs that the base station fails to receive. In the uplink, in addition to setting to transmit HARQ-ACK on a TB basis for uplink transmission, a method may be configured in which CBs constituting TBs for uplink transmission are collected to form CBGs (Code Block Groups) and configured to transmit HARQ-ACK on a CBG basis, thereby informing the terminal of the success or failure of reception for each CBG as CBG level HARQ-ACK feedback, and retransmitting only the CBGs that the terminal fails to receive.

[0102] Figure 11 is a diagram showing an example of a deployment scenario of a terminal and a base station in an LAA service environment. The LAA service environment and the target frequency band have high frequency characteristics, so the wireless communication reach is not long. Considering this, in an environment where conventional LTE-L services and LAA services coexist, the deployment scenario of the terminal and the base station is an overlay model or a co-located model.

[0103] In the overlay model, a macro base station performs wireless communication with terminals X and X' in a macro region 32 using a licensed band carrier, and is connected to a number of RRHs (Radio Remote Heads) via an X2 interface. Each RRH performs wireless communication with terminals X or X' in a certain region 31 using an unlicensed band carrier. Although the macro base station and the RRH frequency bands are different from each other and do not interfere with each other, fast data exchange should be performed between the macro base station and the RRH via the X2 interface in order to use the LAA service as an auxiliary downlink channel for the LTE-L service through carrier aggregation.

[0104] In the co-located model, the pico / femto base station performs wireless communication with the Y terminal by simultaneously using licensed and unlicensed band carriers. However, the pico / femto base station is limited to using both the LTE-L service and the LAA service during downlink transmission. The coverage 33 of the LTE-L service and the coverage 34 of the LAA service may differ depending on the frequency band, transmission power, etc.

[0105] When LTE communication is performed in an unlicensed band, conventional equipment communicating in the corresponding unlicensed band (e.g., wireless LAN (Wi-Fi equipment)) cannot demodulate the NR-U message or data. Therefore, the conventional equipment judges the LAA message or data to be a type of energy and performs interference avoidance operations using energy detection techniques. In other words, if the energy corresponding to the LAA message or data is -62 dBm or less than a specific ED (Energy Detection) threshold value, the WLAN equipment ignores the corresponding message or data and communicates. As a result, from the perspective of a terminal performing LTE communication in an unlicensed band, it may be frequently interfered with by WLAN equipment.

[0106] Therefore, in order to effectively implement LAA-U technology / services, it is necessary to allocate or reserve a specific frequency band for a specific time. However, there is a problem that efficient LAA service is difficult because peripheral devices communicating through unlicensed bands attempt access based on energy detection techniques. Therefore, in order for LAA technology to take root, research on coexistence methods with conventional unlicensed band devices and efficient wireless channel sharing methods should be conducted first. In other words, a strong mechanism should be developed that does not affect conventional unlicensed band devices.

[0107] 12 is a diagram showing a conventional communication method (e.g., wireless LAN) that operates in an unlicensed band. Most devices that operate in an unlicensed band operate based on LBT (Listen-Before-Talk), and therefore perform Clear Channel Assessment (CCA) to sense the channel before transmitting data.

[0108] Referring to FIG. 12, a WLAN device (e.g., AP, STA) performs carrier sensing before transmitting data to check whether a channel is busy. If a wireless signal of a certain strength or more is detected on a channel to transmit data, the channel is determined to be busy, and the WLAN device delays access to the channel. This process is called clear channel evaluation, and the level that determines whether a signal is detected is called a CCA threshold. On the other hand, if no wireless signal is detected on the channel or a wireless signal of a strength lower than the CCA threshold is detected, the channel is determined to be in an idle state.

[0109] If the channel is determined to be in an idle state, a terminal having data to transmit performs a backoff procedure after a defer period (e.g., Arbitration InterFrame Space (AIFS) or PCF IFS (PIFS)). The defer period refers to the minimum time that a terminal must wait after a channel becomes idle. The backoff procedure allows a terminal to wait for an arbitrary amount of time after the defer deadline. For example, a terminal waits while decreasing a slot time of a random number assigned to the terminal within a contention window (CW) while the channel is in an idle state, and a terminal that has exhausted all of the slot times attempts to access the channel.

[0110] If the terminal successfully accesses the channel, it transmits data through the channel. If the data transmission is successful, the contention window size (CWS) is reset to the initial value (CWmin). Conversely, if the data transmission fails, the CWS is doubled. As a result, the terminal is assigned a new random number within a range twice the previous random number range and performs a backoff procedure in the next CW. In WLAN, only ACK is defined as reception response information for data transmission. Therefore, if an ACK is received for data transmission, the CWS is reset to the initial value, and if no feedback information is received for data transmission, the CWS is doubled.

[0111] As mentioned above, most of the conventional communications in unlicensed bands operate based on LBT, so channel access in the LTE system also uses LBT to coexist with conventional devices. In more detail, channel access methods in unlicensed bands in LTE are divided into the following four categories depending on the presence / absence of LBT / application method.

[0112] Category 1: No LBT

[0113] The Tx entity does not perform the LBT procedure for transmission.

[0114] Category 2: LBT without random backoff

[0115] The Tx entity senses whether the channel is idle for a first interval without random backoff in order to transmit. That is, the Tx entity transmits through the channel immediately after sensing that the channel is idle for the first interval. The first interval is an interval of a preset length immediately before the Tx entity transmits. According to one embodiment, the first interval may be an interval of 25 us, but the present invention is not limited thereto.

[0116] Category 3: LBT with random backoff using a fixed-size CW

[0117] The Tx entity acquires a random number within a fixed size CW and sets it as the initial value of a backoff counter (or backoff timer) N, and performs backoff using the set backoff counter N. That is, in the backoff procedure, the Tx entity decreases the backoff counter by 1 each time the channel is sensed as being idle during a preset slot period. Here, the preset slot period may be 9us, but the present invention is not limited thereto. The backoff counter N is decreased by 1 from the initial value, and when the value of the backoff counter N reaches 0, the Tx entity performs transmission. Meanwhile, in order to perform backoff, the Tx entity first senses whether the channel is idle during a second interval (i.e., a defer period Td). The second interval is set based on the channel access priority class of the Tx entity, and is composed of a period of 16us and m consecutive slot periods. Here, m is a value set according to the channel access priority class. If the channel is sensed as being idle during the second interval, the Tx entity performs channel sensing to decrease the backoff counter. Meanwhile, if the channel is sensed as occupied during the backoff procedure, the backoff procedure is aborted. After aborting the backoff procedure, the Tx entity resumes backoff if the channel is sensed as idle for an additional second interval. Thus, the Tx entity transmits if the channel is idle for the second interval plus the slot period of the backoff counter N. In this case, the initial value of the backoff counter N is obtained within the fixed size CW.

[0118] Category 4: LBT with random backoff using variable-size CW

[0119] -The Tx entity obtains a random number within the variable-size CW, sets it as the initial value of the backoff counter (or backoff timer) N, and performs backoff using the set backoff counter N. More specifically, the Tx entity adjusts the size of the CW based on HARQ-ACK information for the previous transmission, and the initial value of the backoff counter N is obtained within the adjusted size of the CW. The detailed process of the Tx entity performing backoff is as described in Category 3. The Tx entity transmits if the channel is idle for the slot period of the backoff counter N in addition to the second interval. In this case, the initial value of the backoff counter N is obtained within the variable-size CW.

[0120] In the above categories 1 to 4, the Tx entity is a base station or a terminal. According to an embodiment of the present invention, the first type of channel access is referred to as Category 4 channel access, and the second type of channel access is referred to as Category 2 channel access.

[0121] 13 and 14 illustrate a DL transmission process based on Category 4 LBT. Category 4 LBT may be used to ensure fair channel access with Wi-Fi. Referring to FIG. 13 and FIG. 14, the LBT process includes ICCA (Initial CCA) and ECCA (Extended CCA). In ICCA, random backoff is not performed, and in ECCA, random backoff is performed using a variable size CW. ICCA is applied when the channel is idle at the time when a signal transmission is required, and ECCA is applied when the channel is in use at the time when a signal transmission is required or there was a DL transmission immediately before. That is, it is determined whether the channel is idle using ICCA, and data transmission is performed after the ICCA period. If an interference signal is recognized and data transmission is not possible, a random backoff counter is set, and then the data transmission time can be obtained by defer period + backoff counter.

[0122] Referring to FIG. 13, the signal transmission process may be performed as follows.

[0123] ICCA (Initial CCA)

[0124] - S302: The base station checks that the channel is idle.

[0125] - S304: The base station checks whether signal transmission is necessary. If signal transmission is not necessary, the process returns to S302. If signal transmission is necessary, the process proceeds to S306.

[0126] - S306: The base station checks whether the channel is idle during an ICCA defer period (BCCA). The ICCA defer period is configurable. In a specific embodiment, the ICCA defer period may be composed of a 16 μs period and n consecutive CCA slots, where n is a positive integer, and one CCA slot period may be 9 μs. The number of CCA slots may be set differently depending on the QoS class. The ICCA defer period may be set to an appropriate value taking into account the Wi-Fi defer period (e.g., DIFS, AIFS). For example, the ICCA defer period may be 34 μs. If the channel is idle during the ICCA defer period, the base station may perform a signal transmission process (S308). If the channel is determined to be in use during the ICCA defer period, the base station proceeds to S312 (ECCA).

[0127] - S308: The base station can perform a signal transmission process. If there is no signal transmission, proceed to S302 (ICCA), and if there is signal transmission, proceed to S310. If the backoff counter N reaches 0 in S318 and S308 is performed, proceed to S302 (ICCA) if there is no signal transmission, and proceed to S310 if there is signal transmission.

[0128] - S310: If no additional signal transmission is required, proceed to S302 (ICCA), otherwise proceed to S312 (ECCA).

[0129] ECCA (Extended CCA)

[0130] - S312: The base station generates a random number N in the CW. N is used as a counter in the backoff process and is generated from [0,q-1]. The CW is composed of q ECCA slots, and the ECCA slot size may be 9 μs or 10 μs. The CW size (CWS) is defined as q and may be variable in S314. The base station then proceeds to S316.

[0131] - S314: The base station may update the CWS. CWSq may be updated to a value between X and Y. The X and Y values ​​are configurable parameters. The CWS update / adjustment may be performed every N generation (dynamic backoff) or may be performed semi-statically at regular time intervals (semi-static backoff). The CWS may be updated / adjusted based on an exponential backoff or a binary backoff. That is, the CWS may be updated / adjusted in the form of a power of 2 or a multiple of 2. In relation to PDSCH transmission, the CWS may be updated / adjusted based on UE feedback / reports (e.g., HARQ ACK / NACK) or based on base station sensing.

[0132] - S316: The base station checks whether the channel is idle during an ECCA defer period (DeCCA). The ECCA defer period is configurable. In a specific embodiment, the ECCA defer period may be composed of a 16 μs period and n consecutive CCA slots, where n is a positive integer, and one CCA slot period may be 9 μs. The number of CCA slots may be set to be different depending on the QoS class. The ECCA defer period may be set to an appropriate value taking into account the Wi-Fi defer period (e.g., DIFS, AIFS). For example, the ECCA defer period may be 34 μs. If the channel is idle during the ECCA defer period, the base station proceeds to S318. If the channel is determined to be in use during the ECCA defer period, the base station repeats S316.

[0133] - S318: The base station checks whether N is 0. If N is 0, the base station can perform the signal transmission process (S308). In this case (i.e., N=0), the base station can continue the ECCA process by not transmitting immediately and performing a CCA check for at least one slot. If N is not 0 (i.e., N>0), proceed to S320.

[0134] - S320: The base station senses the channel for one ECCA slot period (T). The ECCA slot size may be 9 μs or 10 μs, and the actual sensing time may be at least 4 μs.

[0135] - S322: If the channel is determined to be idle, proceed to S324. If the channel is determined to be busy, return to S316, i.e., one ECCA defer period is applied again after the channel is idle, and N is not counted down in the ECCA defer period.

[0136] - S324: Decrease N by 1 (ECCA countdown).

[0137] 14 is substantially the same as / similar to the transmission process of FIG 13, with differences depending on the implementation, so please refer to the contents of FIG 13 for details.

[0138] ICCA (Initial CCA)

[0139] - S402: The base station checks whether signal transmission is necessary. If signal transmission is not necessary, S402 is repeated, and if signal transmission is necessary, proceed to S404.

[0140] - S404: The base station checks whether the slot is idle. If the slot is idle, proceed to S406, otherwise proceed to S412 (ECCA). The slot may correspond to a CCA slot in FIG. 13.

[0141] - S406: The base station checks whether the channel is idle during a defer period (D). D may correspond to the ICCA defer period in FIG. 13. If the channel is idle during the defer period, the base station may perform a signal transmission process (S408). If the channel is determined to be in use during the defer period, the base station proceeds to S404.

[0142] - S408: The base station may perform a signal transmission process when necessary.

[0143] - S410: If there is no signal transmission, proceed to S402 (ICCA), and if there is signal transmission, proceed to S412 (ECCA). Even if the back-off counter N reaches 0 in S418 and S408 is performed, if there is no signal transmission, proceed to S402 (ICCA), and if there is signal transmission, proceed to S412 (ECCA).

[0144] ECCA (Extended CCA)

[0145] - S412: The base station generates a random number N in the CW. N is used as a counter in the backoff process and is generated from [0, q-1]. The CW size (CWS) is defined as q and may be varied in S414. The base station then proceeds to S416.

[0146] - S414: The base station can update the CWS. CWSq may be updated to a value between X and Y. The X and Y values ​​are configurable parameters. The CWS update / adjustment may be performed every N generation (dynamic backoff) or may be performed semi-statically at regular time intervals (semi-static backoff). The CWS may be updated / adjusted based on an exponential backoff or a binary backoff. That is, the CWS may be updated / adjusted in the form of a power of 2 or a multiple of 2. In relation to PDSCH transmission, the CWS may be updated / adjusted based on UE feedback / reports (e.g., HARQ ACK / NACK) or based on base station sensing.

[0147] - S416: The base station checks whether the channel is idle in a defer period (D). D may correspond to the ECCA defer period in FIG. 13. D may be the same in S406 and S416. If the channel is idle in the defer period, the base station proceeds to S418. If the channel is determined to be busy during the defer period, the base station repeats S416.

[0148] - S418: The base station checks whether N is 0. If N is 0, the base station can perform a signal transmission process (S408). In this case (N=0), the base station can continue the ECCA process by not transmitting immediately and performing a CCA check for at least one slot. If N is not 0 (i.e., N>0), proceed to S420.

[0149] - S420: The base station selects one of the following operations: decrementing N by 1 (ECCA countdown) or not decrementing N (self-deferral). The self-deferral operation may be implemented / selected by the base station. In self-deferral, the base station does not perform sensing for energy detection, nor does it perform ECCA countdown.

[0150] - S422: The base station can select one of an operation without sensing for energy detection and an energy detection operation. If sensing for energy detection is not performed, proceed to S424. If the energy detection operation is performed, and the energy level is below the energy detection threshold (i.e., idle), proceed to S424. If the energy level exceeds the energy detection threshold (i.e., busy), return to S416. That is, one defer period is applied again after the channel is idle, and N is not counted down in the defer period.

[0151] - Proceed to S424:S418.

[0152] FIG. 15 shows an example in which a base station performs DL transmission in an unlicensed band. A base station can aggregate one or more licensed band cells (LTE-L cell or NR-L cell (NR-Licensed cell) for convenience) and one or more unlicensed band cells (LTE-U cell or NR-U cell (NR-Unlicensed cell) for convenience). FIG. 15 assumes a case in which one LTE-L cell and one LTE-U cell are aggregated for communication with a terminal. The LTE-L cell may be a PCell, and the LTE-U cell may be a SCell. In an LTE-L cell, a base station exclusively uses frequency resources and can perform operations according to existing LTE. Therefore, each radio frame is composed of a regular subframe (rSF) having a length of 1 ms (see FIG. 2), and DL transmission (e.g., PDCCH, PDSCH) may be performed every subframe (see FIG. 1). On the other hand, in an LTE-U cell, DL transmission is performed based on LBT in order to coexist with existing devices (e.g., Wi-Fi devices). Also, in order to effectively implement LTE-U technologies / services, it is necessary to allocate or reserve a specific frequency band at a specific time. Therefore, in an LTE-U cell, DL transmission may be performed in one or more consecutive subframe sets after LBT (DL transmission burst). Depending on the LBT situation, the DL transmission burst may start in a regular subframe (rSF) as shown in FIG. 15(a) or in a partial subframe (pSF) as shown in FIG. 15(b). The pSF is a portion of a subframe and may include the second slot of the subframe. Also, the DL transmission burst may end in either the rSF or the pSF.

[0153] Hereinafter, a method for adaptively adjusting CWS during channel access in unlicensed band is proposed. CWS may be adjusted based on UE (User Equipment) feedback, and UE feedback used for CWS adjustment may include HARQ-ACK response, CQI / PMI / RI. In the present invention, a method for adaptively adjusting CWS based on HARQ-ACK response is proposed. HARQ-ACK response includes ACK, NACK, and DTX.

[0154] As described with reference to Fig. 12, in Wi-Fi, CWS is also adjusted based on ACK. When ACK feedback is received, CWS is reset to a minimum value (CWmin), and when ACK feedback is not received, CWS is increased. However, in a cellular system (e.g., LTE), a CWS adjustment method that takes multiple connections into account is required.

[0155] First, in order to explain the present invention, the following terms are defined:

[0156] - Set of HARQ-ACK feedback values ​​(HARQ-ACK feedback set): refers to HARQ-ACK feedback values ​​used for CWS update / adjustment. The HARQ-ACK feedback set corresponds to the HARQ-ACK feedback values ​​that are decoded and available at the time when the CWS is determined. The HARQ-ACK feedback set includes HARQ-ACK feedback values ​​for one or more DL (channel) transmissions (e.g., PDSCH) on an unlicensed band (e.g., LTE-U cell). The HARQ-ACK feedback set may include HARQ-ACK feedback values ​​for DL ​​(channel) transmissions (e.g., PDSCH), for example, multiple HARQ-ACK feedback values ​​fed back from multiple terminals. The HARQ-ACK feedback value indicates reception response information for a transmission block or PDSCH, and may indicate ACK, NACK, DTX, or NACK / DTX. Depending on the context, the HARQ-ACK feedback value may be rephrased as a HARQ-ACK value / bit / response / information, etc.

[0157] - Reference window: A time interval during which DL transmission (e.g., PDSCH) corresponding to a HARQ-ACK feedback set is performed in an unlicensed band (e.g., an LTE-U cell). It may be defined in SF units. This will be described / proposed in more detail later.

[0158] In LTE, the HARQ-ACK value can indicate only ACK and NACK or can further indicate DTX depending on the HARQ-ACK feedback method or PUCCH format, etc. For example, when PUCCH format 3 is set as the HARQ-ACK feedback method, the HARQ-ACK value can indicate only ACK and NACK. On the other hand, when a channel selection method using PUCCH format 1b is set as the HARQ-ACK feedback method, the HARQ-ACK value can indicate ACK, NACK, DTX, or NACK / DTX.

[0159] Referring to FIG. 16, after the base station transmits the n-th DL transmission burst in an unlicensed band (e.g., an LTE-U cell) (S502), if an additional DL transmission is required, the base station can transmit the (n+1)-th DL transmission burst based on ECCA (S512). Specifically, if the channel of the unlicensed band is empty during the ECCA defer period, the base station further performs random 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 only for slots corresponding to the random number N (S510). In the present invention, the CWS is adjusted based on a HARQ-ACK feedback value from the terminal (S506). The HARQ-ACK feedback value used for the CWS adjustment includes a HARQ-ACK feedback value related to the last DL transmission burst (n-th DL transmission burst). The HARQ-ACK feedback value used for CWS adjustment includes a HARQ-ACK feedback value for a DL transmission over a reference window within a DL transmission burst (S504).

[0160] In the above description of the present invention, the LTE-based LAA cell is defined as an LTE-U cell, but similarly, NR-L cell and LTE-L cell in NR may be replaced, and NR-U cell and LTE-U cell may be replaced and applied to the present invention. However, differences using NR-U cells are applied to the NR-U cells when separately mentioned in the specific matters of the present invention.

[0161] <BWP operation for wideband operation in the NR system>

[0162] Figure 17 is an example of a method for configuring a BWP having a bandwidth smaller than or equal to the bandwidth of a carrier (or cell) in a 3GPP NR system for a terminal.

[0163] Referring to Figure 17, in a 3GPP NR system, a terminal can transmit and receive using a bandwidth smaller than or equal to the bandwidth of a carrier (or cell). For this purpose, multiple BWPs may be configured for the terminal by a base station. A BWP is composed of consecutive PRBs. Referring to Figure 17(a), the BWPs may be separated without overlapping. One or more of the non-overlapping separated BWPs may be allocated and configured for the terminal. The terminal can transmit and receive with the base station using the allocated and configured BWP. Referring to Figure 17(b), the BWPs may be separated with the carrier bandwidth overlapping. At this time, one BWP may be configured to be included in another BWP. One or more of the overlapping separated BWPs may be allocated and configured for the terminal. The terminal can transmit and receive with the base station using one of the allocated and configured BWPs.

[0164] Figure 18 is an example of a method for configuring or allocating a CORESET to a BWP allocated to a terminal.

[0165] Referring to FIG. 18, when a plurality of BWPs are assigned to a terminal, at least one CORESET may be configured or assigned to each BWP. Referring to FIG. 18(a) and FIG. 18(b), when BWPs are configured to not overlap each other and when BWPs are configured to overlap each other, a CORESET for each BWP may be located within a time / frequency resource region occupied by each BWP. In other words, a CORESET #1 for a bandwidth part #1 may be located within a PRB in a time / frequency resource region occupied by the bandwidth part #1, and a CORESET #2 for a bandwidth part #2 may be located within a PRB in a time / frequency resource region occupied by the bandwidth part #2. Referring to FIG. 18(b), when bandwidth parts are configured to overlap each other, a PRB occupied by a CORESET may be located within a time / frequency resource region of its own bandwidth part or in another bandwidth part. In other words, CORESET #2 for Bandwidth part #2 may overlap with PRBs in the time / frequency resource region occupied by Bandwidth part #1.

[0166] In a time division duplex (TDD) cell, up to four downlink BWPs (DL BWPs) and up to four uplink BWPs (UL BWPs) may be configured per cell. A terminal may activate one DL BWP and one UL BWP simultaneously in one cell. In a frequency division duplex (FDD) cell, up to four DL / UL BWP pairs may be configured per cell. A terminal may activate one DL / UL BWP simultaneously in one cell. The terminal does not expect to receive any signals on PRBs other than the activated DL BWP, and does not expect to transmit any signals on PRBs other than the activated UL BWP. For a terminal to move from one BWP to another, the base station uses downlink control information (DCI) to instruct the terminal to deactivate the BWP currently used and activate a new BWP. More specifically, in order to change the DL BWP of a terminal in a TDD cell, the DCI for scheduling a PDSCH includes a BPI (Bandwidth part indicator) indicating the BWP to be activated. That is, when the terminal receives the DCI for scheduling a PDSCH, the BPI indicates which BWP the PDSCH is to be transmitted on. Then, the terminal can determine which PRB of the BWP the PDSCH is to be transmitted on from resource allocation (RA) information of the DCI. Similarly, in order to change the UL BWP of a terminal in a TDD cell, the DCI for scheduling a PUSCH includes a BPI indicating the BWP to be activated. That is, when the terminal receives the DCI for scheduling a PUSCH, the BPI indicates which BWP the PUSCH should be transmitted on. Then, the terminal can determine which PRB of the indicated BWP the PUSCH should be transmitted on from RA information of the DCI. In the case of an FDD cell, the BWP value of the DCI that schedules the PDSCH and PUSCH may indicate one of a DL / UL BWP pair.

[0167] A wireless communication device operating in a wireless communication system according to an embodiment of the present invention can perform an LBT procedure in a pre-specified bandwidth unit in order to perform an LBT procedure in an unlicensed band. In this case, the pre-specified bandwidth may be called an LBT bandwidth, an LBT subband, or an LBT basic bandwidth. For convenience of explanation, in the following description, the pre-specified bandwidth is called a basic bandwidth. Specifically, when performing channel access, the wireless communication device can determine whether a channel is idle in basic bandwidth units. In a specific embodiment, the wireless communication device can determine whether a channel is idle in pre-specified basic bandwidth units, and determine whether to transmit on the channel based on the determination of whether the channel is idle. In addition, the basic bandwidth may be 20 MHz. This may be in consideration of coexistence with other wireless communication devices (e.g., wireless LAN devices) using the unlicensed band. In this specification, the wireless communication device may refer to a terminal or a base station. In addition, the wireless communication device may refer to both a terminal and a base station. Therefore, both channel access for UL transmission and DL transmission may be performed in basic bandwidth units. In this way, when a wireless communication device performs channel access in a basic bandwidth unit in an unlicensed band, a problem may arise as to how to perform channel access using a bandwidth larger than the basic bandwidth or a method of performing channel access with a BWP having a bandwidth larger than the basic bandwidth. As described above, a BWP is a set of continuous PRBs selected from a plurality of continuous RB subsets for a given numerology in a given carrier. A base station configures one or more DL BWPs for a downlink in a terminal, and the base station can transmit to the terminal with one downlink active DL BWP among the one or more configured DL BWPs. In addition, a base station configures one or more UL BWPs for an uplink in a terminal, and the base station can schedule resources for uplink transmission of the terminal with one uplink active UL BWP among the one or more configured UL BWPs.Specifically, when a frequency resource corresponding to one of the basic bandwidths is idle but other resources corresponding to the basic bandwidths are busy, a channel access method of the wireless communication device may become problematic. This is because when a frequency resource corresponding to one of the basic bandwidths in a BWP is idle but other resources corresponding to the basic bandwidths are busy, the wireless communication device cannot transmit data in the BWP, and spectral efficiency may decrease.

[0168] In a specific embodiment, the base station can allocate the bandwidth of the BWP as the basic bandwidth. In this case, the base station can simultaneously perform downlink transmission with multiple BWPs. The terminal can simultaneously perform uplink transmission with multiple BWPs. In these embodiments, the specific operations of the base station and the terminal may be the same as the channel access operation in multi-carrier defined in 3GPP TS 36.213v14.8.0. In still another specific embodiment, the base station can set the bandwidth of the BWP to an integer multiple of the basic bandwidth. A specific method for a wireless communication device to access a channel using a BWP in a wireless communication system operating in an unlicensed band will be described.

[0169] A base station can configure a plurality of BWPs to a terminal in an unlicensed band. Specifically, a base station can configure a plurality of downlink BWPs to a terminal in an unlicensed band. In this case, the base station can activate a plurality of BWPs to a terminal in an unlicensed band. An operation method of a base station and a terminal in such an embodiment will be described first. A base station can transmit signaling related to a BWP (bandwidth part) and indicate information on an activated BWP to a terminal. A terminal can receive signaling related to a BWP from a base station and determine an activated BWP to the terminal. Specifically, a base station can configure one or more activated downlink BWPs among a plurality of downlink BWPs to a terminal by dedicated RRC signaling. In contrast, as described above, a base station can indicate an activated BWP among the BWPs configured to a terminal by DCI. A terminal can receive a DCI and determine an activated BWP based on the DCI.

[0170] When the base station succeeds in channel access in at least one BWP, the base station can transmit the PDSCH in one or more BWPs that have succeeded in channel access. That is, when the base station succeeds in channel access in a plurality of BWPs, the base station can transmit the PDSCH in a plurality of BWPs. In this case, the base station transmits a PDCCH for scheduling the PDSCH in the BWP that transmits the PDSCH, and each of the PDCCHs can include scheduling information of the PDSCH transmitted in the BWP in which the PDCCH is transmitted. The scheduling information of the PDSCH indicates information on time and frequency resources for transmitting the PDSCH. When a plurality of BWPs among the BWPs configured in the terminal are activated, the terminal cannot determine which BWP among the activated BWPs the base station succeeds in channel access in. Therefore, the terminal can monitor the PDCCH in a CORESET configured in each of the activated BWPs and attempt to receive the PDCCH. The terminal can receive the PDSCH in each BWP using the scheduling information of the PDSCH included in the received PDCCH. The terminal may monitor the PDCCH in all BWPs set in the terminal. Specifically, the terminal may monitor the PDCCH in a CORESET of all BWPs set in the terminal. In addition, the terminal may receive the PDSCH in the BWP based on the scheduling information of the PDSCH included in the received PDCCH. In this embodiment, the terminal must monitor the PDCCH in all BWPs set in the terminal, and the complexity for blind decoding of the PDCCH may increase. In addition, the power consumed by the terminal to receive the PDCCH may also increase. In this specification, successful channel access may mean a case where transmission is permitted on the channel by the channel access procedure. In this case, the channel access procedure may mean the above-mentioned LBT procedure.

[0171] The base station may be configured so that different BWPs have different frequency resources. The base station may also be configured so that frequency resources of different BWPs overlap. For example, when different BWPs are configured to overlap, a part of the frequency resources of the first BWP and a part of the frequency resources of the second BWP may be the same. The frequency resources of the first BWP may include the frequency resources of the second BWP. For convenience of explanation, when frequency resources of different BWPs overlap, the BWPs are called overlapped BWPs. The base station sets a CORESET for each BWP, and the terminal monitors the PDCCH in the CORESET resources of each BWP. When there are overlapping BWPs, the terminal can monitor the PDCCH in sequence from the overlapping BWP according to the priority of the BWPs. In such an embodiment, when the terminal receives the PDCCH in one BWP, the terminal does not need to monitor the PDCCH in a BWP having a lower priority than the BWP in which the PDCCH is received. At this time, the priority may be set based on the bandwidth size of the BWP. In a specific embodiment, a BWP having a relatively wide bandwidth may have a relatively high priority. When the bandwidth of the first BWP is wider than the bandwidth of the second BWP, the terminal may monitor the PDCCH in the first BWP and then monitor the PDCCH in the second BWP. In yet another specific embodiment, a BWP having a relatively narrow bandwidth may have a relatively high priority. When the bandwidth of the first BWP is narrower than the bandwidth of the second BWP, the terminal may monitor the PDCCH in the first BWP and then monitor the PDCCH in the second BWP. Such an operation may be efficient when the base station can transmit in the BWP only if it has successfully accessed the channel in all basic bandwidths included in the BWP. This is because the terminal is highly likely to transmit the PDCCH in the BWP having a narrow bandwidth when the base station can transmit in the BWP only if it has successfully accessed the channel in all basic bandwidths included in the BWP.

[0172] In still another embodiment, even if the base station succeeds in channel access in multiple BWPs, the base station may transmit the PDSCH in one of the multiple BWPs that have succeeded in channel access. At this time, the base station may determine a BWP that transmits the PDSCH among the multiple BWPs that have succeeded in channel access according to the priority order. At this time, the base station may transmit a PDCCH that schedules the PDSCH in the BWP that transmits the PDSCH. The terminal may determine the order of the BWPs that monitor the PDCCH based on the priority order of each of the multiple BWPs. When multiple BWPs are activated in the terminal, the terminal may sequentially monitor the PDCCH in the multiple BWPs according to the priority order of each of the multiple BWPs. At this time, when the terminal receives the PDCCH in any one BWP, the terminal may omit PDCCH monitoring in the BWPs other than the BWP that received the PDCCH. Specifically, when the terminal receives the PDCCH that schedules the PDSCH in any one BWP, the terminal may omit monitoring the PDCCH that schedules the PDSCH in the BWPs other than the BWP that received the PDCCH.

[0173] The priority may be determined based on the index of the BWP. In a specific embodiment, a BWP having a relatively large index may have a relatively high priority. For example, if a base station successfully accesses a channel using the first BWP and the second BWP, and the index of the first BWP is larger than that of the second BWP, the base station may determine that the BWP to transmit the PDSCH is the first BWP among the first BWP and the second BWP. In this case, the terminal may monitor the PDCCH in the first BWP and then monitor the PDCCH in the second BWP. In yet another specific embodiment, a BWP having a relatively small index may have a relatively high priority. For example, if a base station successfully accesses a channel using the first BWP and the second BWP, and the index of the first BWP is smaller than that of the second BWP, the base station may determine that the BWP to transmit the PDSCH is the first BWP among the first BWP and the second BWP. In this case, the terminal may monitor the PDCCH in the first BWP and then monitor the PDCCH in the second BWP. In this case, when the terminal receives a PDCCH in a BWP with a high priority for monitoring the PDCCH, the terminal may omit monitoring the PDCCH in BWPs other than the BWP in which the PDCCH was received. Specifically, when the terminal receives a PDCCH for scheduling a PDSCH in a BWP with a high priority for monitoring the PDCCH, the terminal may omit monitoring the PDCCH for scheduling a PDSCH in BWPs other than the BWP in which the PDCCH was received.

[0174] In yet another specific embodiment, the priority may be determined based on the bandwidth of the BWP. Specifically, a BWP having a relatively narrow bandwidth may have a relatively high priority. For example, when a base station successfully accesses a channel using a first BWP and a second BWP, and the bandwidth of the first BWP is narrower than the bandwidth of the second BWP, the base station may determine that the BWP to transmit the PDSCH is the first BWP among the first BWP and the second BWP. In this case, the terminal may monitor the PDCCH using the first BWP and then monitor the PDCCH using the second BWP. In yet another specific embodiment, a BWP having a relatively wide bandwidth may have a relatively high priority. For example, when a base station successfully accesses a channel using a first BWP and a second BWP, and the bandwidth of the first BWP is wider than the bandwidth of the second BWP, the base station may determine that the BWP to transmit the PDSCH is the first BWP among the first BWP and the second BWP. In this case, the terminal can monitor the PDCCH in the first BWP and then monitor the PDCCH in the second BWP. Also, in the above embodiment, when multiple BWPs have the same bandwidth, the priority order may be determined based on the index of the BWP.

[0175] In yet another specific embodiment, the base station may configure one or more BWPs in the unlicensed band for the terminal, and may be limited to activating only one BWP among the configured one or more BWPs. Thus, even if multiple BWPs are configured for the terminal in the unlicensed band, the base station may activate only one BWP for the terminal in the unlicensed band. In such an embodiment, the operation method of the base station and the terminal will be described first.

[0176] A base station can transmit a PDSCH to a terminal in a BWP only if it has successfully accessed the channel in all basic bandwidths included in the BWP. If a base station has successfully accessed the channel in all basic bandwidths included in the BWP, the base station can transmit a PDCCH for scheduling a PDSCH to a terminal in the BWP. A terminal can monitor a PDCCH in an active BWP among BWPs set in the terminal. Specifically, a terminal can monitor a PDCCH in a CORESET of an active BWP among BWPs set in the terminal. Since a terminal monitors a PDCCH in only one BWP, it is possible to prevent an increase in terminal complexity due to a terminal operating in an unlicensed band. In addition, it is possible to prevent a decrease in power consumption efficiency of a terminal in an unlicensed band. However, if a base station transmits in a BWP only if it has successfully accessed the channel in all basic bandwidths included in the BWP, the spectral efficiency of a downlink transmitted from a base station to a terminal may decrease.

[0177] When the base station successfully accesses a channel in any one of the basic bandwidths included in the BWP, the base station can transmit a PDSCH to the terminal in the BWP using one or more basic bandwidths in which the channel access has been successful. When the base station successfully accesses a channel in any one of the basic bandwidths included in the BWP, the base station can transmit a PDCCH for scheduling a PDSCH to the terminal in the BWP using one or more basic bandwidths in which the channel access has been successful. This embodiment can improve frequency efficiency for the base station to transmit a PDCCH. However, the terminal does not know which basic bandwidth of the one or more basic bandwidths included in the BWP the base station successfully accesses the channel in. Therefore, the terminal can monitor the PDCCH in the CORESET set in the BWP. However, when the CORESET is set in units of the BWP and the base station fails to access the channel in any of the basic bandwidths included in the BWP, the base station may not be able to use a part of the bandwidth of the CORESET and may not be able to transmit the PDCCH in the CORESET. As a result, the terminal may fail to receive the PDCCH in the CORESET. For this reason, the base station may set the CORESET in the basic bandwidth in the BWP. Specifically, when the base station sets the CORSET within the BWP, the base station can set the CORESET within the basic band. The terminal can monitor the PDCCH assuming that the base station can transmit the PDCCH with the CORESET within the basic bandwidth. When the bandwidth size of the BWP set in the terminal, i.e., the number of basic bandwidths, increases, the CORESET can be set within the basic bandwidth, so that the number of CORESETs that the terminal monitors the PDCCH increases. Therefore, there is a disadvantage that the complexity and power consumption of the terminal due to blind decoding of the PDCCH may increase. Therefore, a method for the terminal to efficiently monitor the PDCCH is required. In particular, when the CORESET is set within the basic bandwidth, i.e., when the CORESET has a bandwidth of the same size or smaller than the basic bandwidth, a method for the terminal to efficiently monitor the PDCCH is required. This will be described with reference to Figures 19 to 21.

[0178] FIG. 19 shows that when a base station in an embodiment of the present invention configures a BWP to include one or more basic bandwidths, it transmits a PDCCH in a CORESET configured for each basic bandwidth based on the priority for each basic bandwidth, and transmits a PDSCH within the BWP.

[0179] When the base station has successfully accessed the channel in a plurality of basic bandwidths including the CORESET in the BWP, the base station can transmit a PDCCH for scheduling a PDSCH to the terminal in one of the plurality of basic bandwidths in which the base station has successfully accessed the channel. The base station can divide the plurality of basic bandwidths including the CORESET in the BWP and assign priorities to the plurality of basic bandwidths. Each of the plurality of basic bandwidths may have a unique priority. When the base station has successfully accessed the channel in a plurality of basic bandwidths including the CORESET in the BWP, the base station can determine the basic bandwidth with the highest priority among the basic bandwidths in which the base station has successfully accessed the channel as the bandwidth for transmitting the PDCCH. That is, when the base station has successfully accessed the channel in a plurality of basic bandwidths including the CORESET in the BWP, the base station can transmit the PDCCH to the terminal in the basic bandwidth with the highest priority among the basic bandwidths in which the base station has successfully accessed the channel. For convenience of explanation, the basic bandwidth with the highest priority among the basic bandwidths in which the base station can transmit the PDCCH and in which the base station has successfully accessed the channel is referred to as the highest priority basic bandwidth. The terminal can monitor the PDCCH based on the priority of the basic bandwidths. Specifically, the terminal may determine the order of the basic bandwidths for monitoring the PDCCH based on the priority of the basic bandwidths. When a CORESET is set in the basic bandwidth, the terminal may sequentially monitor the PDCCH in the CORESET of the multiple basic bandwidths according to the priority of each of the multiple basic bandwidths. For example, when the terminal cannot receive the PDCCH in the CORESET set to the bandwidth with the highest priority among the basic bandwidths, the terminal monitors the PDCCH in the CORESET set to the basic bandwidth with the second highest priority. When the terminal receives the PDCCH in any one of the basic bandwidths, the terminal may omit PDCCH monitoring in the remaining basic bandwidths. Specifically, when the terminal receives a PDCCH for scheduling a PDSCH in any one of the basic bandwidths, the terminal may omit monitoring of the PDCCH for scheduling a PDSCH in a basic bandwidth other than the basic bandwidth in which the PDCCH is received.

[0180] In addition, the PDCCH can schedule the PDSCH transmitted in the basic bandwidth for which the base station has successfully accessed the channel. In this case, the PDCCH can schedule the PDSCH transmitted in the basic bandwidth other than the highest priority basic bandwidth in addition to the PDSCH transmitted in the highest priority basic bandwidth. The base station can determine one or more basic bandwidths for transmitting the PDSCH based on the highest priority basic bandwidth. The terminal can receive the PDSCH based on the scheduling information of the PDSCH included in the received PDCCH.

[0181] In addition, the base station can determine the basic bandwidth for transmitting the PDSCH by combining the channel access result in the highest priority basic bandwidth and the channel access result in other basic bandwidths in the BWP. In a specific embodiment, if the base station also succeeds in channel access in the basic bandwidth adjacent to the highest priority basic bandwidth, the base station can transmit the PDSCH based on the highest priority basic bandwidth and the basic bandwidth adjacent to the highest priority basic bandwidth to which the base station has succeeded in channel access. At this time, the base station can transmit the PDSCH in a bandwidth that is an integer multiple of the basic bandwidth (e.g., 20MHz*M, M={1,2,3,4,...,N}, N is a natural number). In yet another specific embodiment, the base station can transmit the PDSCH in a bandwidth that is a power of 2 multiplied by the basic bandwidth (e.g., 20MHz*2L, L={0,1,2,3,...,X}, X is a natural number). In FIG. 19, the LBT unit means the basic bandwidth.

[0182] FIG. 19(a) shows a case where the base station transmits the PDSCH with a bandwidth that is an integer multiple of the basic bandwidth. Case 1 shows a case where the base station succeeds in channel access with the basic bandwidth with the highest priority (Primary LBT unit) and fails to access the channel with the basic bandwidth with the second highest priority (Secondary LBT unit). In Case 1, one basic bandwidth (1 stIn Case 2, the base station is allowed to transmit PDSCH in the basic bandwidth with the highest priority (Primary LBT unit) and the basic bandwidth with the second highest priority (Secondary LBT unit), but fails to access the channel in the basic bandwidth with the third highest priority (Thirdly LBT unit). In Case 2, the base station is allowed to transmit PDSCH in the basic bandwidth with the highest priority (Primary LBT unit) and the basic bandwidth with the second highest priority (Secondary LBT unit). st LBT unit, 2 nd In Case 3, the base station is allowed to transmit PDSCH in the basic bandwidth with the highest priority (Primary LBT unit), the basic bandwidth with the second highest priority (Secondary LBT unit), and the basic bandwidth with the third highest priority (Thirdly LBT unit), but fails to access the channel in the basic bandwidth with the fourth highest priority (Fourthly LBT unit). In Case 3, the base station is allowed to transmit PDSCH in the three basic bandwidths (1 st LBT unit, 2 nd LBT unit, 3 rd In Case 4, the base station is allowed to transmit PDSCH in all (i.e., N) basic bandwidths. st LBT unit, 2 nd LBT unit, 3 rd LBT Unit,…,N th In Case 5, the base station is allowed to transmit PDSCH in one basic bandwidth (2 LBT unit). Case 5 shows a case where the base station succeeds in channel access in the basic bandwidth with the second highest priority (Secondary LBT unit) and fails to access the channel in the basic bandwidth with the highest priority (Primary LBT unit) and the basic bandwidth with the third highest priority (Thirdly LBT unit). In Case 5, ndIn Case 6, the base station is allowed to transmit PDSCH in the second LBT unit and the third LBT unit. Case 7 shows a case where the base station succeeds in channel access in the second LBT unit and the third LBT unit, but fails in channel access in the primary LBT unit and the fourth LBT unit. In Case 7, the base station is allowed to transmit PDSCH in the second LBT unit and the fourth LBT unit. nd LBT unit, 3 rd The base station is allowed to transmit PDSCH in the LBT unit. Case 7 shows the case where the base station has successfully accessed all basic bandwidth channels except for the basic bandwidth with the highest priority (Primary LBT unit). nd LBT unit, 3 rd LBT Unit,…,N th Case 8 shows a case where channel access is successful for the basic bandwidth with the third highest priority (Thirdly LBT unit) and fails for the basic bandwidth with the highest priority (Primary LBT unit), the basic bandwidth with the second highest priority (Secondary LBT unit) and the basic bandwidth with the fourth highest priority (Fourthly LBT unit). In Case 8, PDSCH transmission by the base station is permitted for one basic bandwidth (Thirdly LBT unit). Case 9 shows a case where the base station succeeds in channel access for all basic bandwidths except for the basic bandwidth with the highest priority (Primary LBT unit) and the basic bandwidth with the second highest priority (Secondary LBT unit). In Case 9, PDSCH transmission by the base station is permitted for N-2 basic bandwidths (3 rd LBT Unit,…,N th In Case 10, the base station is allowed to transmit PDSCH in the basic bandwidth (N LBT unit) with the lowest priority. thIn Case 10, the channel access is successful only for one basic bandwidth (N th Transmission of PDSCH in the LBT unit is permitted.

[0183] FIG. 19(b) shows a case where the base station transmits the PDSCH with a bandwidth equal to the basic bandwidth multiplied by a power of 2. Case 1 shows a case where the base station succeeds in channel access with the basic bandwidth with the highest priority (Primary LBT unit) and fails to access the channel with the basic bandwidth with the second highest priority (Secondary LBT unit). In Case 1, one basic bandwidth (1 st In Case 2, the base station is allowed to transmit PDSCH in the basic bandwidth with the highest priority (Primary LBT unit) and the basic bandwidth with the second highest priority (Secondary LBT unit). In Case 3, the base station is allowed to transmit PDSCH in the basic bandwidth with the highest priority (Primary LBT unit) and the basic bandwidth with the second highest priority (Secondary LBT unit), but is allowed to transmit PDSCH in at least one of the basic bandwidth with the third highest priority (Thirdly LBT unit) and the basic bandwidth with the fourth highest priority (Fourthly LBT unit). In Case 2, the base station is allowed to transmit PDSCH in the basic bandwidth with the highest priority (Primary LBT unit) and the basic bandwidth with the second highest priority (Secondary LBT unit). In Case 3, the base station is allowed to transmit PDSCH in the basic bandwidth with the highest priority (Primary LBT unit) and the basic bandwidth with the second highest priority (Secondary LBT unit). In Case 4, the base station is allowed to transmit PDSCH in the basic bandwidth with the highest priority (Primary LBT unit). st LBT unit, 2 nd In Case 3, the base station is permitted to transmit PDSCH in all (i.e., N) basic bandwidths. In Case 3, the base station is permitted to transmit PDSCH in N basic bandwidths. In Case 4, the base station is permitted to transmit PDSCH in one basic bandwidth (2 LBT unit) and succeeds in channel access in the second-highest priority basic bandwidth (Secondary LBT unit), but fails to access the channel in the basic bandwidth (Primary LBT unit) and the third-highest priority basic bandwidth (Thirdly LBT unit). In Case 4, the base station is permitted to transmit PDSCH in one basic bandwidth (2 ndIn Case 5, the base station is allowed to transmit PDSCH in the basic bandwidth with the second highest priority (Secondary LBT unit) and the basic bandwidth with the third highest priority (Thirdly LBT unit). Case 5 shows a case where the base station succeeds in channel access in the basic bandwidth with the second highest priority (Secondary LBT unit) and the basic bandwidth with the third highest priority (Thirdly LBT unit), fails to access the channel in the basic bandwidth with the highest priority (Primary LBT unit), and fails to access the channel in at least one of the basic bandwidth with the third highest priority (Thirdly LBT unit) and the basic bandwidth with the fourth highest priority (Fourthly LBT unit). In Case 5, the base station is allowed to transmit PDSCH in the basic bandwidth with the second highest priority (Secondary LBT unit) and the basic bandwidth with the third highest priority (Thirdly LBT unit). nd LBT unit, 3 rd In Case 6, the base station is allowed to transmit PDSCH in one basic bandwidth (3 LBT unit). Case 6 shows a case where the base station succeeds in channel access for the basic bandwidth with the third highest priority (Thirdly LBT unit) and fails to access the channel for the basic bandwidth with the highest priority (Primary LBT unit), the basic bandwidth with the second highest priority (Secondary LBT unit), and the basic bandwidth with the fourth highest priority (Fourthly LBT unit). In Case 6, the base station is allowed to transmit PDSCH in one basic bandwidth (3 rd In case 7, the base station is allowed to transmit PDSCH in the primary LBT unit and the secondary LBT unit. In case 8, the base station fails to access the channel in the primary LBT unit and the secondary LBT unit. rd LBT unit,…,N th In this case, N-2 is a power of 2. In Case 7, N-2 basic bandwidths (3 rd LBT unit,…,N th In Case 8, the base station is allowed to transmit PDSCH in the basic bandwidth (N LBT unit) with the lowest priority. th In Case 8, the channel access is successful only for one basic bandwidth (N thThe base station is allowed to transmit PDSCH in the LBT unit.

[0184] FIG. 20 shows that when a BWP is configured to include one or more basic bandwidths according to an embodiment of the present invention, the base station transmits a PDCCH in a CORESET configured for each basic bandwidth according to the priority of the specified basic bandwidths, and transmits a PDSCH within the BWP.

[0185] The base station divides the BWP into a plurality of basic bandwidth units, specifies a plurality of priority elementary bandwidths for the terminal to monitor the PDCCH, and can transmit the PDCCH only in the specified priority elementary bandwidths. The base station can set a CORESET within each specified elementary bandwidth. In yet another specific embodiment, the base station can specify a plurality of priority elementary bandwidths from among the basic bandwidths in which the CORESET is set. Also, as described above, the bandwidth of the CORESET can be set within the basic bandwidth. The terminal can monitor the PDCCH only in the specified priority elementary bandwidth.

[0186] One or more basic bandwidths in which the base station can transmit the PDCCH may be specified in the BWP. In this case, the base station can transmit the PDCCH to the terminal based on the channel access result in the specified basic bandwidth. Specifically, the base station can transmit the PDCCH in accordance with the priority of the basic bandwidths specified based on the channel access result in the specified basic bandwidth. The base station can transmit the PDCCH in the basic bandwidth with the highest priority among the specified basic bandwidths and the basic bandwidths for which channel access has been successful. In the embodiment of FIG. 20, the first basic bandwidth (1 st LBT unit) and the third basic bandwidth (3 rd In the embodiment of FIG. 20, the base station specifies the first basic bandwidth (1 st LBT unit) and the third basic bandwidth (3 rd When the channel access is successful in the LBT unit, the base station st The LBT unit can transmit PDCCH.

[0187] The terminal may monitor the PDCCH in the designated basic bandwidth. In this case, the terminal may monitor the PDCCH based on the priority of the designated basic bandwidth. Specifically, the terminal may determine the order of the designated basic bandwidths for monitoring the PDCCH based on the priority of the designated basic bandwidth. For example, if the terminal is unable to receive the PDCCH in a CORESET set to the bandwidth with the highest priority among the designated basic bandwidths, the terminal monitors the PDCCH in the designated basic bandwidth with the second highest priority. If the terminal receives the PDCCH in any one of the designated basic bandwidths, the terminal may omit PDCCH monitoring in the remaining designated basic bandwidths. Specifically, if the terminal receives a PDCCH for scheduling a PDSCH in any one of the basic bandwidths, the terminal may omit monitoring of the PDCCH for scheduling a PDSCH in the remaining designated basic bandwidths.

[0188] In addition, the PDCCH can schedule the PDSCH to be transmitted in the basic bandwidth to which the base station has successfully accessed the channel. In this case, the PDCCH can schedule the PDSCH to be transmitted in the basic bandwidth other than the top priority basic bandwidth in addition to the PDSCH to be transmitted in the top priority basic bandwidth. The base station can transmit the PDCCH in the top priority basic bandwidth, which is the basic bandwidth with the highest priority among the basic bandwidths to which the base station has successfully accessed the channel. Therefore, the top priority basic bandwidth is a specified basic bandwidth and is the basic bandwidth with the highest priority among the basic bandwidths to which the base station has successfully accessed the channel. The base station can determine the basic bandwidth to transmit the PDSCH based on the top priority basic bandwidth. The terminal can receive the PDSCH based on the scheduling information of the PDSCH included in the received PDCCH.

[0189] In addition, the base station can determine the basic bandwidth for transmitting the PDSCH by combining the channel access result in the highest-priority basic bandwidth and the channel access result in other basic bandwidths of the BWP. In a specific embodiment, if the base station also succeeds in channel access in the basic bandwidth adjacent to the highest-priority basic bandwidth, the base station can transmit the PDSCH based on the highest-priority basic bandwidth and the basic bandwidth adjacent to the highest-priority basic bandwidth in which the base station succeeds in channel access. At this time, the base station can transmit the PDSCH with a bandwidth that is an integer multiple of the basic bandwidth (e.g., 20MHz*M, M={1,2,3,4,...,N}, N is a natural number). In yet another specific embodiment, the base station can transmit the PDSCH with a bandwidth that is a power of 2 multiplied by the basic bandwidth (e.g., 20MHz*2L, L={0,1,2,3,...,X}, X is a natural number). In FIG. 20, LBT unit means the basic bandwidth. As described above, in the embodiment of FIG. 20, two basic bandwidths (1 st LBT unit, 3 rd LBT unit) is specified.

[0190] FIG. 20(a) shows a case where the base station transmits the PDSCH in a bandwidth that is an integer multiple of the basic bandwidth. In Case 1, the base station transmits the PDSCH in the first basic bandwidth (1 st LBT unit) successfully accesses the channel and the second basic bandwidth (2 nd In Case 1, one basic bandwidth (1 LBT unit) is used. st In Case 2, the base station is allowed to transmit PDSCH in the first basic bandwidth (Primary LBT unit) which is the basic bandwidth with the highest priority and the second basic bandwidth (2 nd LBT unit) was successfully achieved, and the third basic bandwidth (2 nd This shows the case where channel access fails in the LBT unit. st LBT unit, 2nd In Case 3, the base station is allowed to transmit PDSCH in the first LBT unit, which is the highest priority basic bandwidth (Primary LBT unit), the second LBT unit, and the third LBT unit, but fails to access the channel in the N-th LBT unit. st LBT unit, 2 nd LBT unit, 3 rd In Case 4, the base station is allowed to transmit PDSCH in all (i.e., N) basic bandwidths. st LBT unit, 2 nd LBT unit, 3 rd LBT Unit,…N th The base station is allowed to transmit PDSCH in N basic bandwidths (1 LBT unit). st LBT unit, 2 nd LBT unit, 3 rd LBT Unit,…N th In case 5, the PDSCH is transmitted in the 3rd LBT unit, which is the second highest priority basic bandwidth (Secondary LBT unit). rd The first LBT unit has successfully accessed the channel and is assigned the first LBT unit with the highest priority. st In Case 5, the N-th LBT unit and the N-th LBT unit show the case where channel access is unsuccessful. rd In Case 6, the base station is allowed to transmit PDSCH in the 3rd LBT unit, which is the second highest priority basic bandwidth (Secondary LBT unit). rdThe first LBT unit (1 LBT unit), which is the bandwidth with the highest priority (Primary LBT unit), succeeds in channel access in all basic bandwidths from the fourth basic bandwidth to the nth basic bandwidth, and the second basic bandwidth (1 LBT unit) which is the bandwidth with the highest priority (Primary LBT unit) st In Case 6, the channel access fails at N-2 basic bandwidths (3 rd LBT unit,…N th In case 7, when the Nth basic bandwidth is set 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, one basic bandwidth (N th The base station is allowed to transmit PDSCH in the LBT unit.

[0191] FIG. 20(b) shows a case where the base station transmits the PDSCH with a bandwidth equal to the basic bandwidth multiplied by a power of 2. In Case 1, the base station transmits the PDSCH with the first basic bandwidth (1 st LBT unit) successfully accesses the channel and the second basic bandwidth (2 nd This shows the case where channel access fails in the LBT unit. st In Case 2, the base station transmits the PDSCH in the first basic bandwidth (1 LBT unit), which is the basic bandwidth with the highest priority (Primary LBT unit). st LBT unit) and second basic bandwidth (2 nd LBT unit) successfully accesses the channel and the third basic bandwidth (3 rd In Case 2, the base station fails to access the channel in at least one of the two basic bandwidths (1 LBT unit) and the fourth basic bandwidth (4th LBT unit). st LBT unit, 2 ndIn Case 2, the base station is allowed to transmit PDSCH in the N basic bandwidths. Case 3 shows a case where the base station has succeeded in channel access in all (i.e., N) basic bandwidths. In Case 4, the base station is allowed to transmit PDSCH in the third basic bandwidth (3 LBT unit), which is the basic bandwidth with the second highest priority (Secondary LBT unit). rd The first LBT unit has successfully accessed the channel and is assigned the first LBT unit with the highest priority. st LBT unit) and 4th basic bandwidth (2 nd In Case 4, the base station fails to access the channel in one basic bandwidth (3 LBT units). rd In Case 5, the base station is allowed to transmit PDSCH in the third LBT unit, which is the second highest priority basic bandwidth (Secondary LBT unit). rd LBT unit) and the third basic bandwidth (3 rd After successful channel access in all subsequent LBT units, the first LBT unit (Primary LBT unit) is selected. st In Case 5, the base station fails to access the channel in the LBT unit. rd LBT unit,…N th The base station is permitted to transmit PDSCH in one basic bandwidth (N-th LBT unit), where N-2 is a power of 2. Case 6 shows a case where the base station fails to access the channel in the basic bandwidth with the first and second highest priority when the Nth basic bandwidth is set as the basic bandwidth with the third highest priority. In Case 6, the base station is permitted to transmit PDSCH in one basic bandwidth (N-th LBT unit).

[0192] FIG. 21 shows that when a BWP is configured to include one or more basic bandwidths according to an embodiment of the present invention, one or more basic bandwidths in which a base station can transmit a PDCCH are specified, and the base station transmits a PDCCH in a CORESET set within each basic bandwidth according to the specified basic bandwidth, and transmits a PDSCH within the BWP.

[0193] In the BWP, one or more basic bandwidths in which the base station can transmit the PDCCH may be specified. In this case, the base station can transmit the PDCCH to the terminal based on the channel access result in the specified basic bandwidth. The base station can set a CORESET in each of the specified basic bandwidths. In still another specific embodiment, one or more basic bandwidths in which the PDCCH can be transmitted may be specified from among the basic bandwidths in which the CORESET is set. Also, as described above, the bandwidth of the CORESET may be set in the basic bandwidth. Also, the priority of the specified basic bandwidths for the PDCCH transmission may be the same. Specifically, the base station can transmit the PDCCH in one of the specified basic bandwidths and the basic bandwidths in which the channel access has been successful. At this time, the base station can determine the basic bandwidth in which the PDCCH is transmitted, taking into consideration a scheduling algorithm, etc. Also, the basic bandwidths in which the PDSCH can be scheduled in the PDCCH of the specified basic bandwidth may be basic bandwidths that are not adjacent to each other and are separated (disjoint). In the embodiment of FIG. 21, the first basic bandwidth (1 st LBT unit) and the third basic bandwidth (3 rd In the embodiment of FIG. 21, the base station specifies the first basic bandwidth (1 st LBT unit) and the third basic bandwidth (3 rd When the channel access is successful in the LBT unit, the base station st LBT unit) and the third basic bandwidth (3 rd The PDCCH can be transmitted using one of the LBT units.

[0194] The terminal can monitor the PDCCH in all the designated basic bandwidths. If the terminal successfully receives the PDCCH in any one of the designated basic bandwidths, the terminal may omit monitoring the PDCCH in the remaining designated basic bandwidths. Specifically, if the terminal receives a PDCCH that schedules a PDSCH in any one of the basic bandwidths, the terminal may omit monitoring the PDCCH that schedules a PDSCH in the remaining designated basic bandwidths.

[0195] In addition, the PDCCH can schedule the PDSCH to be transmitted in a specified basic bandwidth for which the base station has successfully accessed the channel. In this case, the PDCCH can schedule the PDSCH to be transmitted in a basic bandwidth other than the specified basic bandwidth in addition to the PDSCH to be transmitted in the specified basic bandwidth. The terminal can receive the PDSCH based on the scheduling information of the PDSCH included in the received PDCCH.

[0196] Also, the base station can determine the basic bandwidth for transmitting the PDSCH by combining the channel access result in the designated basic bandwidth with the channel access result in another basic bandwidth of the BWP. In a specific embodiment, if the base station also succeeds in channel access in the basic bandwidth adjacent to the designated basic bandwidth, the base station can transmit the PDSCH based on the designated basic bandwidth and the basic bandwidth adjacent to the designated basic bandwidth in which the base station succeeds in channel access. At this time, the base station can transmit the PDSCH in a wide bandwidth obtained by multiplying the basic bandwidth by a power of 2 (e.g., 20MHz*2L, L={0,1,2,3,...,X}, X is a natural number). In FIG. 21, LBT unit means the basic bandwidth. As described above, in the embodiment of FIG. 21, two basic bandwidths (1 st LBT unit, 3 rd In the embodiment of FIG. 21, the base station transmits the PDSCH in a bandwidth equal to the basic bandwidth multiplied by a power of 2. In Case 1, the base station transmits the PDSCH in the first basic bandwidth (1st LBT unit) successfully accesses the channel and the second basic bandwidth (2 nd This shows the case where channel access fails in the LBT unit. st In Case 2, the base station is allowed to transmit PDSCH in the first basic bandwidth (1 LBT unit), which is the specified basic bandwidth. st LBT unit) and second basic bandwidth (2 nd LBT unit) successfully accesses the channel and the third basic bandwidth (3 rd This shows a case where channel access fails in at least one of the two basic bandwidths (1 LBT unit) and the 4th basic bandwidth (4th LBT unit). st LBT unit, 2 nd In Case 3, the base station is allowed to transmit PDSCH in the third basic bandwidth (3 LBT unit), which is the specified basic bandwidth. rd LBT unit) and succeeds in channel access and receives the specified basic bandwidth, the first basic bandwidth (1 st LBT unit) and 4th basic bandwidth (2 nd This shows the case where channel access fails in the LBT unit. rd In case 4, the base station is allowed to transmit PDSCH in the third basic bandwidth (3 LBT unit). rd LBT unit), and the third basic bandwidth (3 rd If the channel access is successful in all the basic bandwidths after the LBT unit, the first basic bandwidth (1 st In Case 4, the channel access fails in the LBT unit. rd LBT unit,…N th The base station is allowed to transmit PDSCH in N LBT units, where N-2 is a power of 2.

[0197] The base station can set scheduling information of the PDSCH based on the active BWP. The terminal can determine that the RA field, which is a field for resource allocation (RA) of the DCI of the PDCCH that schedules the PDSCH, allocates resources based on the active BWP. In this case, the terminal can receive the PDSCH based on such a determination. As in the above-mentioned embodiment, the base station can determine a combination of basic bandwidths for transmitting the PDSCH depending on the channel success or failure in each of a plurality of basic bandwidths included in the BWP. Thus, the base station must finally determine the RA field value of the DCI after channel access. In addition, the base station must finally determine the size of the resource for transmitting the PDSCH after channel access. This may increase the complexity of the operation of the base station scheduling the PDSCH transmission and setting the PDCCH. Therefore, a method for indicating the resource used for the PDSCH transmission in the PDCCH is required.

[0198] The base station may set the RA field of the DCI into a first field indicating a basic bandwidth including resources allocated for PDSCH transmission and a second field indicating resources allocated for PDSCH transmission within the basic bandwidth indicated by the first field. Specifically, the first field may indicate a basic bandwidth index identifying a basic bandwidth including resources allocated for PDSCH transmission, or a combination of indexes of the basic bandwidth. Also, the base station may set the value of the RA field of the DCI so that the RA field indicates a basic bandwidth index or a combination of indexes of the basic bandwidth in addition to resources allocated for PDSCH transmission within the basic bandwidth. Specifically, the terminal may determine resources allocated for PDSCH transmission based on the position of the basic bandwidth in which the PDSCH is transmitted, which is included in the PDCCH, and the value of the RA field. For example, in the embodiments of FIG. 19(a), FIG. 20(a), and FIG. 21, when a PDCCH is transmitted in a unit bandwidth (Primary LBT unit) with the highest priority, the RA field can indicate a frequency resource (e.g., Case 1, Case 2, Case 3, and Case 4) including the unit bandwidth (Primary LBT unit) with the highest priority. When a PDCCH is transmitted in a unit bandwidth (Secondary LBT unit) with the second highest priority, the RA field can indicate a frequency resource (e.g., Case 5, Case 6, and Case 7) including the unit bandwidth (Secondary LBT unit) with the second highest priority.

[0199] A base station may transmit a PDCCH in one BWP and schedule a BWP in which the PDCCH is transmitted and a PDSCH in another BWP using the PDCCH. Such scheduling is called BWP switching. When BWP switching occurs in this way, a terminal may need time to retune to a BWP in which a PDSCH is transmitted from a base station in order to receive a PDSCH due to BWP switching. Specifically, BWP switching may include a case in which the frequency of the BWP is changed, a case in which the frequency band of the BWP is changed, and a case in which the bandwidth of the BWP is changed. Depending on such a specific situation, a time gap of several hundred us may be required for the terminal. When PDSCH transmission is performed in a licensed band, a base station may guarantee such a time gap and schedule PDSCH transmission. Considering that a device using an unlicensed band such as a Wi-Fi device performs CCA in units of 9 us, there is a possibility that other wireless communication devices may use frequency resources corresponding to the switched BWP in a time gap that occurs during BWP switching when transmitting a PDSCH in an unlicensed band. Therefore, at the time of BWP switching, the base station can transmit a reservation signal in the changed BWP. Specifically, at the time of BWP switching, the base station can transmit a reservation signal to the frequency resource in which the PDSCH is transmitted in the changed BWP. In a specific embodiment, at the time of BWP switching, the base station can transmit a reservation signal to the frequency resource in which the PDSCH is transmitted in the changed BWP in a time gap for BWP change based on the time domain resource allocation (TDRA) of the PDSCH scheduled in the changed BWP. At this time, the BWP change can include at least one of a change in the central frequency of the BWP, a change in the frequency band of the BWP, and a change in the bandwidth of the BWP. The base station can generate a reservation signal by extending the CP of the OFDM symbol for the PDSCH transmitted by the base station.

[0200] Hereinafter, in this specification, a downlink control channel and data channel reception method and an uplink control channel and data channel transmission method for performing a bandwidth part (BWP) based operation in one carrier for NR-U will be described. In this specification, a downlink control channel and data channel reception method and an uplink control channel and data channel transmission method in a BWP configured with one or more LBT (Listen-Before-Talk) bandwidths (bandwidths) existing in one carrier will be described. An example of a method proposed in this specification is a method in which a base station assigns resources for downlink control channel transmission and resources for downlink data channel transmission by setting an in-carrier guard band when transmitting a downlink channel to a terminal in a BWP configured with two or more LBT bandwidths (or LBT subbands) existing in one carrier, and indicates information on resource assignment. Also, the present specification relates to a method in which a terminal receives a downlink control channel and a downlink data channel on resources assigned by a base station. The method proposed in this specification relates to a method for allocating resources for transmitting an uplink control channel and a data channel by setting an in-carrier guard band when a terminal transmits an uplink channel to a base station and indicating information related to resource allocation, and also relates to a method for a terminal to transmit an uplink control channel and an uplink data channel using resources scheduled (allocated resources) by a base station.

[0201] FIG. 22 is a diagram illustrating an in-carrier guard band and a carrier guard band in a BWP configured with one or more LBT subbands on a wideband carrier according to one embodiment of the present specification.

[0202] An in-carrier guard band and a carrier guard band according to an embodiment of the present specification will be described with reference to FIG. 22. The in-carrier guard band may be a guard band located between a certain bandwidth according to a preset standard in one BWP located in one carrier. For example, it may mean a guard band located at 20 MHz intervals in one BWP in one carrier having a bandwidth of 80 MHz. The carrier guard band may mean a guard band located at both ends of a wideband carrier. The carrier guard band may be set not to be assigned as a resource for channel transmission. On the other hand, the in-carrier guard band may be set to be assigned as a resource for channel transmission. When the base station assigns the in-carrier guard band as a resource for channel transmission, the base station needs to inform the terminal that the resource is available for channel transmission. The channel described in this specification may include a control channel and a data channel, and the channel transmission may have the same meaning as data transmission.

[0203] FIG. 23 is a diagram showing the number of contiguous physical resource blocks (PRBs) available in a BWP having a bandwidth of 20 MHz, 40 MHz, or 80 MHz according to an embodiment of the present specification.

[0204] FIG. 24 is a diagram illustrating the number of physical RBs available as in-carrier guard bands in BWPs having bandwidths of 20 MHz, 40 MHz, and 80 MHz according to one embodiment of the present specification.

[0205] 24, in a BWP having a 20 MHz bandwidth, one subband may be configured with 51 PRBs. In a BWP having a 40 MHz bandwidth, one subband may be configured with 50 PRBs, and the in-carrier guard band between each subband may be configured with 6 PRBs. In a BWP having an 80 MHz bandwidth, one subband may be configured with 49 or 50 PRBs, and the in-carrier guard band between each subband may be configured with 6 or 7 PRBs.

[0206] 28, one subband is continuously available from a BWP having a 20 MHz bandwidth, and 51 PRBs may be used. In a BWP having a 40 MHz bandwidth, two subbands are continuously available, and 106 PRBs (50+6+50, see FIG. 29) may be used. In a BWP having an 80 MHz bandwidth, four subbands are continuously available, and 217 PRBs (50+6+49+7+49+6+50, see FIG. 29) may be used.

[0207] 24 illustrates the number of physical RBs available for each LBT subband in a BWP having a bandwidth of 20 MHz, 40 MHz, or 80 MHz according to an embodiment of the present specification. The intra-carrier guard in FIG. 24 may have the same meaning as the in-carrier guard band described above.

[0208] When receiving the downlink control channel, the terminal cannot recognize whether the in-carrier guard band is allocated as a resource for control channel transmission from the base station. Meanwhile, the terminal may receive an indication of available LBT subbands for channel transmission in a bitmap from the base station via a Group-Common (GC)-PDCCH. However, the terminal cannot determine whether the in-carrier guard band is allocated as a resource for control channel and data channel transmission before the base station indicates available LBT subbands in the GC-PDCCH. Therefore, when the base station intends to transmit a downlink control channel, i.e., a PDCCH, to the terminal, the base station can configure a control resource set (CORESET) in resources other than the in-carrier guard band for the terminal. The base station can transmit the PDCCH to the terminal using the CORESET resource. That is, the CORESET may be allocated in available LBT subbands, and may be allocated in frequency resources other than the in-carrier guard band in the available LBT subbands. The base station may configure the terminal to monitor the PDCCH in a CORESET consisting of resources other than the in-carrier guard band. The terminal may monitor the PDCCH in the CORESET resources consisting of resources other than the in-carrier guard band configured by the base station, and perform blind detection of the PDCCH.

[0209] Meanwhile, the base station may indicate available LBT subbands to the terminal via the GC-PDCCH in a bitmap at a time other than the start of a DL burst. In this case, when the terminal receives the GC-PDCCH, there is no ambiguity between the terminal and the base station as to whether the in-carrier guard band is allocated as a resource for channel transmission. However, if the base station indicates the availability of consecutive LBT subbands for channel transmission via the GC-PDCCH but the terminal fails to detect the GC-PDCCH, the terminal does not know whether the in-carrier guard band is available as a resource for channel transmission. Therefore, even if the base station sets the in-carrier guard band as available as a resource for channel transmission via the GC-PDCCH, the terminal may not be able to recognize it. Therefore, there may be ambiguity between the base station and the terminal as to the resource allocation of the in-carrier guard band (whether the in-carrier guard band is used for channel transmission).

[0210] In other words, the base station may allocate resources for channel transmission (e.g., CORESET) to the terminal to monitor the PDCCH, taking into consideration whether the in-carrier guard band is available for channel transmission. That is, if the in-carrier guard band is unavailable for channel transmission, the resources for channel transmission may be configured on subbands in the BWP separated by the in-carrier guard band. The base station may then instruct the terminal to monitor the PDCCH to receive the PDCCH on the resources for channel transmission. The base station may then transmit the PDCCH on the resources for channel transmission. The terminal may then perform blind detection of the PDCCH on the resources for channel transmission. The base station may transmit information regarding whether the in-carrier guard band has been allocated as a resource for channel transmission, taking into consideration that the in-carrier guard band is available as a resource for channel transmission, to the terminal. The base station may then instruct whether each of the subbands in the BWP separated by the in-carrier guard band is to be used for downlink channel transmission. In this case, information regarding whether the in-carrier guard band has been allocated as a resource for channel transmission considering that it can be used as a resource for channel transmission and whether each subband is used for downlink channel transmission may be indicated in the form of a bitmap.

[0211] Therefore, this specification proposes a method for a base station to indicate whether the in-carrier guard band is available as a resource for channel transmission. Specifically, the present specification proposes a method of indicating whether the in-carrier guard band is available as a resource for channel transmission by downlink control channel (Downlink Control Information, DCI) signaling, which is a dynamic scheduling method.

[0212] In downlink transmission, the base station can perform channel access in units of LBT bandwidths within a BWP consisting of two or more LBT bandwidths (or LBT subbands). Whether consecutive LBT subbands within a BWP are available for channel transmission may be determined depending on whether the in-carrier guard band is available as a resource for channel transmission. Therefore, when the base station succeeds in channel access, the base station must indicate to the terminal whether the resource allocation was performed by considering the in-carrier guard band as available as a resource for channel transmission or the in-carrier guard band as unavailable as a resource for channel transmission.

[0213] A terminal can receive frequency domain resource allocation (FDRA) information from a base station through DCI. However, the terminal does not know the result of channel access performed by the base station in a downlink BWP consisting of two or more LBT bandwidths (or LBT subbands) configured by the base station for the terminal. Therefore, when continuous LBT subbands in the BWP are available for channel transmission, the terminal does not know whether the base station has performed downlink resource allocation considering the in-carrier guard band as a resource available for channel transmission or has performed resource allocation for downlink transmission based on resources other than the in-carrier guard band. Therefore, the base station can transmit signaling to the terminal indicating whether the base station has performed resource allocation for downlink transmission considering whether the in-carrier guard band is available as a resource for channel transmission. When the terminal receives such signaling, there is no ambiguity as to whether the in-carrier guard band is available as a resource for channel transmission when allocating frequency resources for downlink transmission between the terminal and the base station. Then, the terminal can receive the PDSCH based on frequency resource allocation information for downlink transmission transmitted by the base station through the DCI.

[0214] When allocating resources for downlink channel transmission to a terminal, the base station must provide an indication as to whether the resource allocation was performed with the in-carrier guard band considered as a usable resource for channel transmission or the resource allocation was performed with the in-carrier guard band considered as an unusable resource for channel transmission. The following methods can be used to provide such indication:

[0215] (Method 1) Method 1 is a method in which the base station uses an RRC configuration to signal to the terminal whether or not the in-carrier guard band may be allocated as a resource for channel transmission.

[0216] The in-carrier guard band may be set as an unallocable resource for data channel transmission by RRC configuration. In this case, 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. Then, the terminal can analyze frequency resource allocation information related to the data channel to receive the data channel.

[0217] Conversely, the in-carrier guard band may be set as an allocatable resource for channel transmission by RRC configuration. At this time, the base station may determine whether the in-carrier guard band can be used as a resource for channel transmission. Specifically, the base station may determine whether the RB in which the in-carrier guard band is actually located is used as a resource for channel transmission according to the result of channel access for consecutive LBT subbands. Therefore, a method in which the base station indicates whether the RB in which the in-carrier guard band is actually located is used as a resource for channel transmission using DCI may be considered. That is, the terminal may assume that a frequency resource including the in-carrier guard band is allocatable for channel transmission. Then, the terminal may be instructed by DCI whether the RB in which the in-carrier guard band is actually located is used as a resource for channel transmission. Then, the terminal may analyze frequency resource allocation information regarding the data channel using the indicated information and receive the data channel.

[0218] The above-mentioned RRC configuration may be commonly applied to downlink channel transmission and uplink channel transmission. Specifically, whether the in-carrier guard band can be allocated as a resource for channel transmission may be set by the same RRC configuration for downlink channel transmission and uplink channel transmission.

[0219] Alternatively, settings based on independent RRC configurations may be applied to downlink channel transmission and uplink channel transmission, or settings based on RRC configurations may be applied only to downlink channel transmission.

[0220] In uplink channel transmission, resources scheduled for a terminal may be resources allocated to consecutive LBT subbands, and all of the consecutive LBT subbands may be successfully accessed. In this case, the terminal may transmit uplink channels using resources allocated to the scheduled consecutive LBT subbands. In this case, when scheduling as resources allocated to consecutive LBT subbands, the base station does not need to instruct the terminal whether the in-carrier guard band is used for channel transmission. This is because the base station may allocate resources to the DCI in consideration of whether the in-carrier guard band is used for channel transmission. Therefore, when the terminal successfully accesses channels using consecutive LBT subbands, the consecutive LBT subbands including the in-carrier guard band should transmit uplink channels to the base station using scheduled resources, so no ambiguity regarding the in-carrier guard band between the terminal and the base station occurs. Therefore, in the case of uplink transmission, there is no need for an RRC configuration for setting whether the in-carrier guard band can be allocated as a resource for channel transmission.

[0221] However, in the case of downlink channel transmission, even if all of the consecutive LBT subbands are not successful in channel access, downlink transmission is possible in some of the LBT subbands that have been successfully accessed. Therefore, an RRC configuration indicating whether the in-carrier guard band can be allocated as a resource for downlink channel transmission may be necessary. Similarly, in the case of uplink channel transmission, similar to downlink transmission, scheduled resources are resources allocated to consecutive LBT subbands, and even if all of the consecutive LBT subbands are not successful in channel access, uplink channel transmission may be possible in some of the successful LBT subbands. In this case, even in the case of uplink channel transmission, an RRC configuration indicating whether the in-carrier guard band can be allocated as a resource for uplink transmission is necessary.

[0222] (Method 2) Method 2 is a method based on dynamic signaling, in which a base station uses DCI to signal whether or not an in-carrier guard band can be allocated as a resource for channel transmission.

[0223] a) By using an explicit signaling method, the base station can indicate whether the in-carrier guard band is included in the resources for receiving the PDSCH by using a 1-bit sized field of the DCI for scheduling the PDSCH. Specifically, the base station can indicate information that all RBs in which the in-carrier guard band is located are included in the resources for scheduling the PDSCH by the DCI for instructing the scheduling of the PDSCH. The terminal receives the DCI and analyzes frequency domain resource allocation (FDRA) information indicated by the DCI, thereby finally grasping the frequency resource allocation information on which the PDSCH is transmitted.

[0224] b) By using an implicit signaling method, the base station can inform the terminal of frequency resource allocation information allocated for PDSCH transmission according to the result of channel access performed by the base station. Specifically, the base station can separately indicate the LBT subbands allocated for PDSCH transmission to the terminal. Alternatively, the base station can include information on the LBT subbands in the DCI and transmit the frequency resource allocation information by joint coding. When the base station transmits frequency resource allocation information to the terminal, the terminal can determine resource allocation for consecutive LBT subbands using the information. At this time, the terminal can determine that the resource allocation for PDSCH transmission has been performed by considering the in-carrier guard band as available for channel transmission. On the other hand, when the base station transmits frequency resource allocation information to the terminal, the terminal can determine that the resource allocation is not for consecutive LBT subbands using the information. At this time, when the terminal receives frequency resource allocation information through DCI, the terminal can determine that the base station has performed resource allocation for PDSCH transmission by considering the in-carrier guard band as unavailable as a resource for channel transmission.

[0225] (Method 3) The base station may indicate whether the in-carrier guard band can be allocated as a resource for channel transmission using the RRC configuration. When it is indicated that the in-carrier guard band can be allocated as a resource for channel transmission, the base station may include RBs used in the in-carrier guard band based on the BWP configured in the terminal when allocating resources for downlink transmission. However, whether the RBs used in the in-carrier guard band are used in frequency resource allocation for actual downlink transmission may be determined according to the FDRA value of DCI. In this case, RB indexing is required to allocate frequency resources for downlink transmission that can be indicated by the FDRA value of DCI. The RB indexing method may be a method in which the RBs used in the in-carrier guard band are indexed last, rather than a method in which the RBs used in the in-carrier guard band are indexed consecutively. The reason for using such an RB indexing method is that the base station can indicate to the terminal whether the in-carrier guard band can actually be used for channel transmission according to the FDRA value of DCI, and the terminal can determine whether the in-carrier guard band is included in the actual resource allocation scheduling. In other words, if the base station indicates to the terminal that the in-carrier guard band can be allocated as a resource for channel transmission through RRC signaling, but the base station does not succeed in channel access in consecutive LBT subbands, the in-carrier guard band cannot be allocated to the terminal. This is to prevent the terminal from changing the method of analyzing FDRA depending on whether the base station has successfully accessed the channel, since the terminal does not know whether the base station has successfully accessed the channel. For example, looking at only two LBT subbands of a 40 MHz carrier in FIG. 24, the first LBT subband may be composed of 50 RBs, the second LBT subband may be composed of 50 RBs, and the in-carrier guard band may be composed of 6 RBs.In this case, the 50 RBs constituting the first subband and the 50 RBs constituting the second subband may be indexed from index 0 to 99, and the 6 RBs constituting the in-carrier guard band may be indexed from index 100 to 105. The base station may allocate resources for downlink transmission by transmitting the start position and length of the RB to the terminal using a resource indication value (RIV) field of the DCI, and may allocate resources for PDSCH transmission by forming an RB group (RBG) by collecting one or more RBs and notifying the position of the allocated resources by bitmap. In these methods, regardless of whether the base station has succeeded in channel access, the base station may separately transmit information (FDRA information) that the RBs included in the in-carrier guard band have been allocated as resources for PDSCH transmission to the terminal. The terminal may then receive the PDSCH by analyzing the common FDRA information using the above-mentioned indexing method, regardless of whether the base station has succeeded in channel access.

[0226] FIG. 25 is a block diagram showing configurations of a terminal and a base station according to an embodiment of the present disclosure. In the embodiment of the present disclosure, the terminal may be embodied as various wireless communication devices or computer devices that are guaranteed to be portable and mobile. The terminal may also be called User Equipment (UE), Station (STA), Mobile Subscriber (MS), etc. In addition, in the embodiment of the present disclosure, the base station may control and manage cells (e.g., macrocells, femtocells, picocells, etc.) corresponding to a service area, and may have functions such as signal transmission, channel assignment, channel monitoring, self-diagnosis, and relaying. The base station may also be called next generation Node B (gNB) or Access Point (AP), etc.

[0227] As shown, the terminal 100 according to one 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 .

[0228] First, the processor 110 can execute various instructions or programs to process data within the terminal 100. The processor 110 can also control the overall operation of the terminal 100 including each unit, and control data transmission and reception between the units. Here, the processor 110 may be configured to perform operations according to the embodiments described in the present disclosure. For example, the processor 110 can receive slot configuration information, determine the slot configuration based on the information, and perform communication according to the determined slot configuration.

[0229] Next, the communication module 120 may be an integrated module that performs wireless communication using a wireless communication network and wireless LAN connection using a wireless LAN. For this purpose, the communication module 120 may include a plurality of network interface cards (NICs) such as cellular communication interface cards 121 and 122 and an unlicensed band communication interface card 123 in an internal or external form. Although the communication module 120 is shown as an integrated module in the figure, each network interface card may be independently arranged depending on the circuit configuration or application, unlike the drawing.

[0230] The cellular communication interface card 121 can transmit and receive wireless signals to and from at least one of the base station 200, the external device, and the server using a mobile communication network, and can provide a cellular communication service in a first frequency band based on an instruction of the processor 110. According to an embodiment, the cellular communication interface card 121 can include at least one NIC module using a frequency band below 6 GHz. The at least one NIC module of the cellular communication interface card 121 can independently perform cellular communication with at least one of the base station 200, the external device, and the server according to a cellular communication standard or protocol of the frequency band below 6 GHz supported by the NIC module.

[0231] The cellular communication interface card 122 can transmit and receive wireless signals to and from at least one of the base station 200, the external device, and the server using a mobile communication network, and can provide a cellular communication service in the second frequency band based on instructions from the processor 110. According to an embodiment, the cellular communication interface card 122 can include at least one NIC module using a frequency band of 6 GHz or higher. The at least one NIC module of the cellular communication interface card 122 can independently perform cellular communication with at least one of the base station 200, the external device, and the server according to a cellular communication standard or protocol of the frequency band of 6 GHz or higher supported by the NIC module.

[0232] The unlicensed band communication interface card 123 transmits and receives wireless signals to and from at least one of the base station 200, the external device, and the server using the third frequency band, which is an unlicensed band, and provides communication services in the unlicensed band based on instructions from the processor 110. The unlicensed band communication interface card 123 may include at least one NIC module using the unlicensed band. For example, the unlicensed band may be 2.4 GHz, 5 GHz, 6 GHz, 7 GHz, or a 5 GHz band that is equal to or greater than 52.6 GHz. The at least one NIC module of the unlicensed band communication interface card 123 may perform wireless communication with at least one of the base station 200, the external device, and the server, independently or dependently, according to an unlicensed band communication standard or protocol of the frequency band supported by the NIC module.

[0233] Next, the memory 130 stores a control program and various data used by the terminal 100. Such a control program may include a predetermined program required for the terminal 100 to perform wireless communication with at least one of the base station 200, an external device, and a server.

[0234] Next, the user interface 140 includes various types of input / output means provided in the terminal 100. That is, the user interface 140 can receive user input using various input means, and the processor 110 can control the terminal 100 based on the received user input. Also, the user interface 140 can perform output based on an instruction of the processor 110 using various output means.

[0235] Then, the display unit 150 outputs various images on a display screen, and the display unit 150 can output various display objects, such as a user interface, based on the content executed by the processor 110 or the control instructions of the processor 110.

[0236] Moreover, the base station 200 according to an embodiment of the present disclosure may include a processor 210 , a communication module 220 , and a memory 230 .

[0237] First, the processor 210 can execute various instructions or programs to process data within the base station 200. The processor 210 can also control the overall operation of the base station 200 including each unit, and control data transmission and reception between the units. Here, the processor 210 may be configured to perform operations according to the embodiments described in the present disclosure. For example, the processor 210 can signal slot configuration information and perform communication according to the signaled slot configuration.

[0238] Next, the communication module 220 may be an integrated module that performs wireless communication using a wireless communication network and wireless LAN connection using a wireless LAN. For this purpose, the communication module 120 may include a plurality of network interface cards, such as cellular communication interface cards 221 and 222 and an unlicensed band communication interface card 223, in an internal or external form. In the figure, the communication module 220 is shown as an integrated module, but each network interface card may be independently arranged depending on the circuit configuration or application, unlike the drawing.

[0239] The cellular communication interface card 221 can transmit and receive wireless signals to and from at least one of the terminal 100, the external device, and the server using a mobile communication network, and can provide a cellular communication service in a first frequency band based on an instruction of the processor 210. According to an embodiment, the cellular communication interface card 221 can include at least one NIC module using a frequency band below 6 GHz. The at least one NIC module of the cellular communication interface card 221 can independently perform cellular communication with at least one of the terminal 100, the external device, and the server according to a cellular communication standard or protocol of the frequency band below 6 GHz supported by the NIC module.

[0240] The cellular communication interface card 222 can transmit and receive wireless signals to and from at least one of the terminal 100, an external device, and a server using a mobile communication network, and can provide a cellular communication service in the second frequency band based on instructions from the processor 210. According to an embodiment, the cellular communication interface card 222 can include at least one NIC module using a frequency band of 6 GHz or higher. The at least one NIC module of the cellular communication interface card 222 can independently perform cellular communication with at least one of the terminal 100, an external device, and a server according to a cellular communication standard or protocol of the frequency band of 6 GHz or higher supported by the NIC module.

[0241] The unlicensed band communication interface card 223 transmits and receives wireless signals to and from at least one of the terminal 100, the external device, and the server using the third frequency band, which is an unlicensed band, and provides communication services of the unlicensed band based on instructions from the processor 210. The unlicensed band communication interface card 223 may include at least one NIC module using the unlicensed band. For example, the unlicensed band may be 2.4 GHz, 5 GHz, 6 GHz, 7 GHz, or a 5 GHz band that is equal to or greater than 52.6 GHz. The at least one NIC module of the unlicensed band communication interface card 223 may perform wireless communication with at least one of the terminal 100, the external device, and the server, independently or dependently, according to an unlicensed band communication standard or protocol of the frequency band supported by the NIC module.

[0242] The terminal 100 and the base station 200 shown in FIG. 25 are block diagrams according to an embodiment of the present disclosure, and the separately displayed blocks are used to logically distinguish the elements of the devices. Therefore, the above-mentioned device elements may be implemented as one chip or multiple chips depending on the design of the device. In addition, some components of the terminal 100, such as the user interface 140 and the display unit 150, may be selectively provided in the terminal 100. In addition, the user interface 140 and the display unit 150 may be further provided in the base station 200 as necessary.

[0243] The above-described embodiments of the present invention may be implemented in various ways. For example, the embodiments of the present invention may be implemented in hardware, firmware, software, or a combination thereof.

[0244] In the case of hardware implementation, the method according to the embodiment of the present invention may be implemented by one or more 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, microprocessors, etc.

[0245] In a firmware or software implementation, the method according to the embodiment of the present invention may be implemented in the form of a module, procedure, or function that performs the functions or operations described above. The software code may be stored in a memory and run by a processor. The memory may be located inside or outside the processor, and data may be exchanged with the processor by various means known in the art.

[0246] FIG. 26 is a flowchart illustrating a method for receiving a downlink channel performed by a terminal according to one embodiment of the present invention.

[0247] With reference to FIG. 26, a method for the terminal to receive a downlink channel transmitted from a base station, as described with reference to FIGS. 1 to 25, will be described.

[0248] The terminal may receive, from the base station, first information related to a guard band in a first resource region located in one carrier (S2610).

[0249] The terminal may receive, from the base station, second information related to a plurality of resource sets separated by the guard bands based on the first information within the first resource region (S2620).

[0250] The terminal may receive a downlink channel from the base station on resources that the second information indicates as available for receiving the downlink channel (S2630).

[0251] In this case, the plurality of resource sets may be configured with resources other than resources allocated for the guard band based on the first information.

[0252] The second information may be information indicating whether each of the plurality of resource sets is available for receiving the downlink channel. The first information may be information related to whether resources allocated for the guard band are used for receiving the downlink channel. Step S2620 may be performed when resources allocated for the guard band are not used for receiving the downlink channel according to the first information.

[0253] After step S2610, the terminal may receive a Physical Downlink Control Channel (PDCCH) on some of the plurality of resource sets from the base station, where the second information may be included in Downlink Control Information (DCI) of the PDCCH.

[0254] In this case, the DCI may be a group-common DCI, that is, the DCI may be a format 2_0 DCI.

[0255] Also, after step S2610, the terminal may receive information about a second resource region that the terminal monitors for receiving the PDCCH from the base station.

[0256] The second resource region may be a portion of the plurality of resource sets, and the second resource region may include resources from which the PDCCH is received.

[0257] The second resource region may be a resource to which a control resource set (CORESET) is assigned.

[0258] The second information may indicate, in a bitmap format, whether each of the plurality of resource sets is available for use in transmitting the downlink channel.

[0259] In this case, the downlink channel in step S2630 may be at least one of a physical downlink control channel (PDCCH) and a physical downlink shared channel (PDSCH).

[0260] The first information and the information regarding the second resource region may be transmitted by higher layer signaling (e.g., RRC configuration).

[0261] A terminal that receives a downlink channel transmitted from a base station may be configured to include a transceiver, a processor operatively coupled to the transceiver, and a memory coupled to the processor that stores instructions for operations performed by the processor.

[0262] In this case, the operations performed by the processor may be the same as those described in FIG.

[0263] Some embodiments may be embodied in the form of a recording medium including computer executable instructions such as a program module executed by the computer. A computer readable medium may be any available medium accessible by a computer, including both volatile and non-volatile media, separate and non-separate media. Also, a computer readable medium may include both computer storage media and communication media. A computer storage medium includes both volatile and non-volatile, separate and non-separate media embodied in any method or technology for storage of information such as computer readable instructions, data structures, program modules or other data. A communication medium typically includes computer readable instructions, data structures or other data in a modulated data signal such as a program module, or other transmission mechanism, and includes any information delivery media.

[0264] The above description of the present invention is for illustrative purposes only, and those skilled in the art will understand that the present invention can be easily modified into other specific forms without changing the technical idea or essential features of the present invention. Therefore, the above-described embodiments should be understood as illustrative and not restrictive in all respects. For example, each component described as a single type may be implemented in a distributed form, and similarly, each component described as being distributed may be implemented in a combined form.

[0265] The scope of the present invention is defined by the claims set forth below rather than the above detailed description, and all modifications and variations that fall within the meaning and scope of the claims and their equivalents should be interpreted as being included within the scope of the present invention.

Claims

1. A method for receiving a downlink channel in a wireless communication system, the method being performed by a terminal, comprising: receiving, from a base station, first information related to a guard band in a first resource region located in one carrier; receiving, from the base station, second information related to a plurality of resource sets in the first resource region, the resource sets being partitioned by the guard bands based on the first information; and receiving a downlink channel from the base station on resources that the second information indicates as available for receiving the downlink channel; the plurality of resource sets are configured with resources other than resources allocated for the guard band based on the first information; The method, wherein the second information is information indicating whether each of the plurality of resource sets is available for receiving the downlink channel.

2. receiving a physical downlink control channel (PDCCH) from the base station on some of the resource sets; The method of claim 1 , wherein the second information is included in downlink control information (DCI) of the PDCCH.

3. The method according to claim 2, wherein the DCI is a group-common DCI.

4. The method of claim 2, further comprising: receiving, from the base station, information regarding a second resource region that the terminal monitors for receiving the PDCCH.

5. the second resource region is a portion of the plurality of resource sets; The method of claim 4, wherein the second resource region includes resources on which the PDCCH is received.

6. The method of claim 5, wherein the second resource region is a resource to which a control resource set (CORESET) is assigned.

7. The method of claim 1, wherein the second information indicates, in a bitmap format, whether each of the plurality of resource sets is available for the downlink channel transmission.

8. The method of claim 1, wherein the downlink channel is at least one of a Physical Downlink Control Channel (PDCCH) and a Physical Downlink Shared Channel (PDSCH).

9. The method of claim 1 , wherein the first information and the information about the second resource region are transmitted by higher layer signaling.

10. A terminal for receiving a downlink channel in a wireless communication system, the terminal comprising: Transmitter / receiver; A processor; and a memory coupled to the processor for storing instructions for operations to be performed by the processor; The operation includes: receiving, from a base station, first information related to a guard band in a first resource region located in one carrier; receiving, from the base station, second information related to a plurality of resource sets in the first resource region, the resource sets being partitioned by the guard bands based on the first information; and receiving, from the base station, a downlink channel on resources that the second information indicates as available for transmitting the downlink channel; the plurality of resource sets are configured with resources other than resources allocated for the guard band based on the first information; The terminal, wherein the second information is information indicating whether each of the plurality of resource sets is available for receiving the downlink channel.

11. The operation includes: receiving a physical downlink control channel (PDCCH) from the base station on some of the resource sets; The terminal according to claim 10, wherein the second information is included in downlink control information (DCI) of the PDCCH.

12. The terminal according to claim 11, wherein the DCI is a group-common DCI.

13. The operation includes: The terminal of claim 11, further comprising: receiving, from the base station, information regarding a second resource region that the terminal monitors for receiving the PDCCH.

14. The terminal of claim 13, wherein the second resource region is a portion of the plurality of resource sets, and the second resource region includes resources from which the PDCCH is received.

15. The terminal of claim 14, wherein the second resource region is a resource to which a control resource set (CORESET) is assigned.

16. The terminal of claim 10, wherein the second information indicates, in a bitmap format, whether each of the plurality of resource sets is available for the downlink channel transmission.

17. The terminal of claim 10, wherein the downlink channel is at least one of a physical downlink control channel (PDCCH) and a physical downlink shared channel (PDSCH).

18. The terminal of claim 10, wherein the first information and the information regarding the second resource region are transmitted by higher layer signaling.

19. A method for transmitting a downlink in a wireless communication system, the method being performed by a base station, comprising: transmitting, to a terminal, first information related to a guard band in a first resource region located in one carrier; transmitting, to the terminal, second information related to a plurality of resource sets separated by the guard bands based on the first information within the first resource region; and transmitting, to the terminal, a downlink channel on resources that the second information indicates as available for transmitting the downlink channel; the plurality of resource sets are configured with resources other than resources allocated for the guard band based on the first information; The method, wherein the second information is information indicating whether each of the plurality of resource sets is available for the downlink channel transmission.

20. The method of claim 19, wherein the second information indicates, in a bitmap format, whether each of the plurality of resource sets is available for the downlink channel transmission.

Images