Method and device for transmitting and receiving data in unlicensed frequency band

Abstract

Embodiments of the present invention relate to a method and device for sending and receiving data in an unlicensed frequency band. One embodiment provides a method for a user equipment to send and receive data in an unlicensed frequency band, the method comprising: receiving configuration information from a base station, the configuration information including parameters for configuring multiple resource block sets in the unlicensed frequency band; confirming multiple resource block sets based on the configuration information; and sending and receiving data with the base station through at least one resource block set, the at least one resource block set being determined based on a result of performing listen-before-talk (LBT) on each of the multiple resource block sets received from the base station.

Description

Technical Field

[0001] The present embodiment relates to a method and apparatus for transmitting and receiving data in an unlicensed frequency band in a next generation radio access network (hereinafter referred to as New Radio, “NR”). Background Art

[0002] Recently, the 3rd Generation Partnership Project (3GPP) approved "Study on New Radio Access Technologies," a research project to investigate next-generation / 5G radio access technologies (hereinafter referred to as "New Radio" or "NR"). Building on this research, the Radio Access Network Working Group 1 (RAN WG1) has been discussing the frame structure, channel coding and modulation, waveforms, multiple access methods, and other aspects of New Radio (NR). Designing NR not only requires providing higher data rates than Long Term Evolution (LTE) / LTE-Advanced, but also meets various requirements in detailed and specific usage scenarios.

[0003] As representative use cases for NR, enhanced mobile broadband (eMBB), massive machine-type communications (mMTC), and ultra-reliable and low-latency communications (URLLC) have been proposed. To meet the requirements of various scenarios, NR needs to be designed with a flexible frame structure compared to LTE / LTE-Advanced.

[0004] Since requirements for data rate, latency, reliability, coverage, etc. are different from each other, a method for efficiently multiplexing radio resource units based on a parameter set different from others (for example, subcarrier spacing, subframe, transmission time interval (TTI)), etc., is needed as a method for efficiently meeting the requirements of each usage scenario by the frequency band constituting any NR system.

[0005] Therefore, a design is needed to transmit and receive data between a base station and a user equipment using unlicensed frequency bands in NR. Summary of the Invention

[0006] Technical issues

[0007] Embodiments of the present disclosure may provide a method and apparatus for configuring at least one sub-frequency band in an unlicensed frequency band and transmitting and receiving data based on a listen-before-talk (LBT) result of the configured at least one sub-frequency band.

[0008] Technical Solution

[0009] On the one hand, an embodiment of the present invention may provide a method for a user equipment (UE) to send and receive data in an unlicensed frequency band, the method may include: receiving configuration information from a base station, the configuration information including parameters for configuring multiple resource block sets in the unlicensed frequency band; confirming multiple resource block sets based on the configuration information; and sending and receiving data with the base station through at least one resource block set, the at least one resource block set being determined based on a result of performing listen-before-talk (LBT) on each of the multiple resource block sets received from the base station.

[0010] On the other hand, an embodiment of the present invention may provide a method for a base station to send and receive data in an unlicensed frequency band, the method may include: sending configuration information to a user equipment, the configuration information including parameters for configuring multiple resource block sets in the unlicensed frequency band; sending the result of listening before talking (LBT) on each of the multiple resource block sets; and sending and receiving data to the user equipment through at least one resource block set determined based on the result of performing LBT, each of the multiple resource block sets consisting of multiple resource blocks of a number determined based on the configuration information.

[0011] On the other hand, an embodiment of the present invention may provide a user equipment for transmitting and receiving data in an unlicensed frequency band, wherein the user equipment may include: a transmitter configured to send data to a base station, a receiver configured to receive configuration information from the base station, the configuration information including parameters for configuring multiple resource block sets in the unlicensed frequency band, and a controller configured to confirm multiple resource block sets based on the configuration information, the receiver receives data from the base station through at least one resource block set determined based on the result of performing listen-before-talk (LBT) on each of the multiple resource block sets received from the base station, and the transmitter sends data to the base station through at least one resource block set.

[0012] In another aspect, a base station for transmitting and receiving data in an unlicensed frequency band may be provided. The base station may include: a receiver configured to receive data from a user equipment (UE); a transmitter configured to transmit configuration information, transmit a result of performing listen-before-talk (LBT) on each of a plurality of RB sets, and transmit data to the UE via at least one RB set determined based on the result of performing LBT, wherein the configuration information includes parameters for configuring the plurality of RB sets in the unlicensed frequency band; and a controller configured to perform LBT on each of the plurality of RB sets, wherein each of the plurality of RB sets is composed of a plurality of RBs of a number determined based on the configuration information.

[0013] Beneficial effects

[0014] According to an embodiment of the present disclosure, a method and apparatus capable of configuring one or more sub-bands in an unlicensed frequency band and transmitting and receiving data based on a listen-before-talk (LBT) result of the configured one or more sub-bands may be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 1 is a diagram schematically illustrating an NR wireless communication system to which an embodiment of the present disclosure can be applied;

[0016] Figure 2 is a diagram schematically illustrating a frame structure in an NR system to which an embodiment of the present disclosure can be applied;

[0017] Figure 3 is a diagram for explaining a resource grid supported by a radio access technology to which an embodiment of the present disclosure may be applied;

[0018] Figure 4 is a diagram for explaining bandwidth portions supported by radio access technologies to which embodiments of the present disclosure may be applied;

[0019] Figure 5 is a diagram showing an example of a synchronization signal block in a radio access technology to which an embodiment of the present disclosure can be applied;

[0020] Figure 6 is a diagram for explaining a random access procedure in a radio access technology to which an embodiment of the present disclosure can be applied;

[0021] Figure 7 It is a diagram used to illustrate CORESET;

[0022] Figure 8 is a diagram illustrating an example of symbol-level alignment between subcarrier spacings (SCSs) different from each other to which an embodiment of the present disclosure can be applied;

[0023] Figure 9 is a diagram schematically illustrating a portion of bandwidth to which embodiments of the present disclosure may be applied;

[0024] Figure 10 is a diagram illustrating a process of receiving downlink data in an unlicensed band by a UE according to an embodiment;

[0025] Figure 11 is a diagram illustrating a process of transmitting downlink data in an unlicensed frequency band by a base station according to an embodiment.

[0026] Figure 12 FIG. 1 is a diagram for explaining LBT for wireless communication in an unlicensed band according to an embodiment of the present disclosure.

[0027] Figure 13 and Figure 14is a diagram showing a configuration of sub-bands for a bandwidth portion configured in a UE according to an embodiment;

[0028] Figure 15 is a diagram showing a configuration of sub-bands of a system bandwidth portion for a cell configured in an unlicensed band according to an embodiment.

[0029] Figure 16 and Figure 17 is a diagram showing a configuration of sub-bands for an SCS specific carrier bandwidth portion according to an embodiment;

[0030] Figure 18 is a diagram showing a configuration of a UE according to other embodiments; and

[0031] Figure 19 is a diagram showing a configuration of a base station according to other embodiments. DETAILED DESCRIPTION

[0032] Hereinafter, some embodiments of the present disclosure will be described in detail with reference to the attached illustrative drawings. In the accompanying drawings, even if the same reference numerals are shown on different drawings, the same reference numerals are used throughout the drawings to represent the same elements. In addition, in the following description of the present disclosure, when the detailed description of known functions and configurations incorporated herein may make the subject matter of the present disclosure unclear, its detailed description will be omitted. When the expressions "including", "having", "comprising" and the like mentioned herein are used, any other parts may be added unless the expression "only" is used. When an element is represented in the singular, the element may cover the plural form unless the element is explicitly mentioned.

[0033] In addition, when describing the components of the present disclosure, terms such as first, second, A, B, (A), (B), etc. may be used herein. Each of these terms is not used to define the nature, order, or sequence of the corresponding component, but is only used to distinguish the corresponding component from other (one or more) components.

[0034] When describing the positional relationship between components, if two or more components are described as being “connected,” “combined,” or “coupled” to each other, it should be understood that the two or more components may be directly “connected,” “combined,” or “coupled,” and that the two or more components may be “connected,” “combined,” or “coupled” to each other with another component “interposed” therebetween. In this case, the other component may be included in at least one of the two or more components that are “connected,” “combined,” or “coupled” to each other.

[0035] In the description of a series of operating methods or manufacturing methods, for example, the use of expressions such as "after," "subsequently," "next," "before," etc. may also cover the case where the operations or processes are not performed continuously unless "immediately" or "directly" is used in the expression.

[0036] Numerical values ​​mentioned herein for components or information corresponding thereto (e.g., levels, etc.) may be construed as including error ranges caused by various factors (e.g., process factors, internal or external influences, noise, etc.) even if no explicit description thereof is provided.

[0037] The wireless communication system in this specification refers to a system for providing various communication services such as voice services and data services using radio resources. The wireless communication system may include user equipment (UE), base stations, a core network, and the like.

[0038] The embodiments disclosed below can be applied to wireless communication systems using various radio access technologies. For example, the embodiments can be applied to various radio access technologies 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), non-orthogonal multiple access (NOMA), etc. In addition, radio access technology can refer to various generations of communication technologies established by various communication organizations such as 3GPP, 3GPP2, Wi-Fi, Bluetooth, IEEE, ITU, etc., as well as specific access technologies. For example, CDMA can be implemented as a wireless technology such as Universal Terrestrial Radio Access (UTRA) or CDMA2000. TDMA can be implemented as a wireless technology such as Global System for Mobile Communications (GSM) / General Packet Radio Service (GPRS) / Enhanced Data Rates for GSM Evolution (EDGE). OFDMA can be implemented as a wireless technology such as IEEE (Institute of Electrical and Electronics Engineers) 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802-20, Evolved UTRA (E-UTRA), etc. IEEE 802.16m is a development of IEEE 802.16e, which is backward compatible with systems based on IEEE 802.16e. UTRA is part of the Universal Mobile Telecommunications System (UMTS). 3GPP (3rd Generation Partnership Project) LTE (Long Term Evolution) is a part of E-UMTS (Evolved UMTS) using Evolved UMTS Terrestrial Radio Access (E-UTRA), which adopts OFDMA in the downlink and SC-FDMA in the uplink. As described above, the embodiments can be applied to radio access technologies that have already been launched or commercialized, and can be applied to radio access technologies that are being developed or will be developed in the future.

[0039] The term UE used in the specification must be interpreted in a broad sense, indicating a device including a wireless communication module that communicates with a base station in a wireless communication system. For example, UE includes: user equipment (UE) in WCDMA, LTE, NR, HSPA, IMT-2020 (5G or New Radio), etc., a mobile station in GSM, a user terminal (UT), a subscriber station (SS), a wireless device, etc. In addition, depending on the type of use of the V2X communication system, the UE may be a portable user device such as a smart phone, or may be a vehicle, a device including a wireless communication module in a vehicle, etc. In the case of a machine type communication (MTC) system, the UE may refer to an MTC terminal, an M2M terminal, or a URLLC terminal, which employs a communication module capable of performing machine type communication.

[0040] In this specification, a base station or cell refers to a terminal that communicates with a UE through a network and is intended to encompass various coverage areas, such as a Node-B, an evolved Node-B (eNB), a gNB (gNode-B), a low-power node (LPN), a sector, a site, various types of antennas, a base transceiver system (BTS), an access point, a point (e.g., a transmission point, a reception point, or a transmission / reception point), a relay node, a megacell, a macrocell, a microcell, a picocell, a femtocell, a remote radio head (RRH), a radio unit (RU), a small cell, and the like. Furthermore, the term "cell" may be used to refer to a bandwidth part (BWP) in the frequency domain. For example, a serving cell may refer to the active BWP of a UE.

[0041] The various cells listed above are provided with a base station that controls one or more cells, and the base station can be interpreted in two meanings. The base station can be 1) a device for providing a megacell, macrocell, microcell, picocell, femtocell or small cell connected to a wireless area, or the base station can be 2) the wireless area itself. In the above description 1), the base station can be a device that is controlled by the same entity and provides a predetermined wireless area, or it can be all devices that interact with each other and collaborate to configure the wireless area. For example, depending on the configuration method of the wireless area, the base station can be a point, a transmission / reception point, a transmission point, a reception point, etc. In the above description 2), the base station can be a wireless area in which a user equipment (UE) can be enabled to send data to and receive data from another UE or an adjacent base station.

[0042] In this specification, a cell may refer to coverage of a signal transmitted from a transmission / reception point, a component carrier having coverage of a signal transmitted from a transmission / reception point (or transmission point), or a transmission / reception point itself.

[0043] The uplink (UL) refers to the scheme for transmitting data from the UE to the base station, while the downlink (DL) refers to the scheme for transmitting data from the base station to the UE. The downlink can refer to the communication or communication path from multiple transmission / reception points to the UE, and the uplink can refer to the communication or communication path from the UE to multiple transmission / reception points. In the downlink, the transmitter can be part of multiple transmission / reception points, and the receiver can be part of the UE. In addition, in the uplink, the transmitter can be part of the UE, and the receiver can be part of multiple transmission / reception points.

[0044] The uplink and downlink transmit and receive control information on control channels such as the Physical Downlink Control Channel (PDCCH) and the Physical Uplink Control Channel (PUCCH). The uplink and downlink transmit and receive data on data channels such as the Physical Downlink Shared Channel (PDSCH) and the Physical Uplink Shared Channel (PUSCH). Hereinafter, the transmission and reception of signals on channels such as the PUCCH, PUSCH, PDCCH, PDSCH, etc. may be referred to as "transmission and reception of PUCCH, PUSCH, PDCCH, PDSCH, etc."

[0045] For clarity, the following description will focus on a 3GPP LTE / LTE-A / NR (New Radio) communication system, but the technical features of the present disclosure are not limited to the corresponding communication systems.

[0046] After studying 4G (fourth generation) communication technology, 3GPP has been developing 5G (fifth generation) communication technology in order to meet the requirements of ITU-R for next-generation radio access technology. Specifically, 3GPP has developed LTE-Apro as 5G communication technology by improving LTE-Advanced technology to meet the requirements of ITU-R and the new NR communication technology that is completely different from 4G communication technology. LTE-Apro and NR both refer to 5G communication technology. In the following, unless a specific communication technology is specified, 5G communication technology will be described based on NR.

[0047] Operational scenarios in NR define various operation scenarios taking into account satellite, automotive, new vertical markets, etc. in existing 4G LTE scenarios, thereby supporting enhanced mobile broadband (eMBB) scenarios in terms of services, massive machine type communication (mMTC) scenarios with high UE density distributed over a wide area requiring low data rates and asynchronous connections, and high reliability and low latency (URLLC) scenarios requiring high responsiveness and reliability and supporting high-speed mobility.

[0048] To meet this scenario, NR introduces a wireless communication system that adopts new waveform and frame structure technologies, low-latency technologies, ultra-high frequency band (mmWave) support technologies, and forward compatibility provision technologies. In particular, the NR system has various technical variations in terms of flexibility to provide forward compatibility. Its main technical features will be described below with reference to the accompanying drawings.

[0049] <Overview of NR System>

[0050] Figure 1 is a diagram schematically showing an NR system to which this embodiment can be applied.

[0051] Refer to Figure 1 , the NR system is divided into a 5G core network (5GC) and an NG-RAN part. The NG-RAN includes gNBs and ng-eNBs that provide control plane (RRC) protocol endpoints for the user plane (SDAP / PDCP / RLC / MAC / PHY) and user equipment (UE: User Equipment). The gNBs or gNBs and ng-eNBs are connected to each other through the Xn interface. The gNBs and ng-eNBs are connected to the 5GC through the NG interface respectively. The 5GC can be configured to include an access and mobility management function (AMF) for managing the control plane (such as UE connection and mobility control functions, etc.), and a user plane function (UPF) for managing user data control functions. NR supports frequency bands below 6 GHz (FR1, frequency range 1) and frequency bands equal to or greater than 6 GHz (FR2, frequency range 2).

[0052] A gNB represents a base station that provides NR user plane and control plane protocol endpoints to the UE. An ng-eNB represents a base station that provides E-UTRA user plane and control plane protocol endpoints to the UE. The base stations described in this specification should be understood to cover both gNBs and ng-eNBs. However, as needed, the base stations can also be used separately to refer to gNBs or ng-eNBs.

[0053] <NR Waveform, Parameter Set, and Frame Structure>

[0054] NR uses the CP-OFDM waveform with a cyclic prefix for downlink transmission and uses CP-OFDM or DFT-s-OFDM for uplink transmission. OFDM technology is easy to combine with multiple-input multiple-output (MIMO) schemes and allows for the use of a low-complexity receiver with high frequency efficiency.

[0055] Because the three scenarios described above have different requirements for data rate, latency, and coverage in NR, it is necessary to efficiently meet the requirements of each scenario across the frequency bands that make up the NR system. To this end, technologies have been proposed for efficiently multiplexing radio resources based on a variety of different numerologies.

[0056] Specifically, the NR transmission parameter set is determined based on the subcarrier spacing and the cyclic prefix (CP). As shown in Table 1 below, "μ" is used as an exponential value of 2, thereby changing exponentially based on 15kHz.

[0057] [Table 1]

[0058] μ Subcarrier spacing cyclic prefix Supporting Data Support synchronization 0 15 normal yes yes 1 30 normal yes yes 2 60 Normal, Extended yes no 3 120 normal yes yes 4 240 normal no yes

[0059] As shown in Table 1 above, NR can have five types of parameter sets according to the subcarrier spacing. This is different from LTE, one of the 4G communication technologies, in which the subcarrier spacing is fixed to 15kHz. Specifically, in NR, the subcarrier spacing for data transmission is 15, 30, 60 or 120kHz, and the subcarrier spacing for synchronization signal transmission is 15, 30, 120 or 240kHz. In addition, the extended CP is only applicable to a subcarrier spacing of 60kHz. A frame consisting of 10 subframes and having a length of 10ms is defined in the frame structure in NR, and each subframe has the same length of 1ms. A frame can be divided into half frames of 5ms, and each half frame includes 5 subframes. When the subcarrier spacing is 15kHz, one subframe includes one time slot, and each time slot includes 14 OFDM symbols. Figure 2 This is a diagram for explaining a frame structure in an NR system to which this embodiment can be applied. Figure 2 In the case of a normal CP, a time slot is fixedly composed of 14 OFDM symbols, but the length of the time slot can vary according to the subcarrier spacing. For example, in the case of a parameter set with a subcarrier spacing of 15kHz, the time slot is configured to have the same length of 1ms as the subframe. On the other hand, in the case of a parameter set with a subcarrier spacing of 30kHz, the time slot includes 14 OFDM symbols, but one subframe can include two time slots, each of which has a length of 0.5ms. That is, a fixed time length can be used to define subframes and frames, and a time slot can be defined as the number of symbols so that its time length varies according to the subcarrier spacing.

[0060] In addition, NR defines the basic unit of scheduling as a time slot and also introduces micro time slots (or sub - slot - based or non - time - slot - based scheduling) to reduce the transmission delay in the radio section. If a wide sub - carrier spacing is used, the length of a time slot is shortened inversely, thereby reducing the transmission delay in the radio section. The minimum time slot (or sub - slot) is designed to effectively support the URLLC scenario, and the minimum time slot can be scheduled in units of 2, 4, or 7 symbols.

[0061] In addition, different from LTE, NR defines the uplink and downlink resource allocation at the symbol level within a time slot. To reduce the HARQ delay, a time slot structure that can directly send HARQ ACK / NACK in the transmission time slot has been defined. This time slot structure is referred to as an "independent structure".

[0062] NR is designed to support a total of 256 time slot formats, and 62 of these time slot formats are used in 3GPP Rel - 15. In addition, NR supports the common frame structure that constitutes the FDD or TDD frame through various combinations of time slots. For example, NR supports: i) a time slot structure where all symbols of the time slot are configured as downlink; ii) a time slot structure where all symbols are configured as uplink; and iii) a time slot structure where downlink symbols and uplink symbols are combined. In addition, NR supports scheduling data transmission to be allocated to one or more time slots. Therefore, the base station can use the Time Slot Format Indicator (SFI) to notify the UE whether the time slot is a downlink time slot, an uplink time slot, or a flexible time slot. The base station can indicate the time slot format by using the index of a table configured by UE - specific RRC signaling through the SFI. In addition, the time slot format can be dynamically indicated by Downlink Control Information (DCI), or can be statically or semi - statically indicated by RRC signaling.

[0063] <Physical Resources of NR>

[0064] Regarding the physical resources in NR, antenna ports, resource grids, resource elements, resource blocks, bandwidth parts, etc. can be considered.

[0065] An antenna port is defined such that a channel carrying a symbol on an antenna port can be inferred from another channel carrying another symbol on the same antenna port. If the large - scale attributes of a channel carrying a symbol on an antenna port can be inferred from another channel carrying a symbol on another antenna port, the two antenna ports may have a quasi - co - located or quasi - co - location (QC / QCL) relationship. Here, the large - scale attributes include at least one of delay spread, Doppler spread, frequency shift, average received power, and reception timing.

[0066] Figure 3It is a diagram for explaining a resource grid supported by radio access technology according to an embodiment of the present disclosure.

[0067] Reference Figure 3 , since NR supports multiple parameter sets in the same carrier, resource grids can exist according to each parameter set. Additionally, depending on the antenna port, subcarrier spacing, and transmission direction, resource grids can exist.

[0068] A resource block includes 12 subcarriers and is defined only in the frequency domain. Additionally, a resource element includes one OFDM symbol and one subcarrier. Therefore, as Figure 3 shown, the size of a resource block can vary according to the carrier spacing. Furthermore, in NR, "Point A" which serves as a common reference point for the resource block grid, common resource blocks, virtual resource blocks, etc. are defined.

[0069] Figure 4 It is a diagram for explaining a bandwidth part supported by radio access technology according to an embodiment of the present disclosure.

[0070] Unlike LTE which fixes the carrier bandwidth at 20 MHz, in NR, according to each subcarrier spacing, the maximum carrier bandwidth is configured to be 50 MHz to 400 MHz. Therefore, it is not assumed that all UEs use the entire carrier bandwidth. Thus, in NR, as Figure 4 shown, a bandwidth part (BWP) can be specified within the carrier bandwidth for use by a UE. Additionally, the bandwidth part can be associated with one parameter set, can include a subset of consecutive common resource blocks, and can be dynamically activated over time. A UE has at most four bandwidth parts in each of the uplink and downlink. The UE uses the activated bandwidth part to send and receive data at a given time.

[0071] In the case of paired spectrum, the uplink and downlink bandwidth parts are configured independently. In the case of unpaired spectrum, to prevent unnecessary frequency retuning between downlink operation and uplink operation, the downlink bandwidth part and the uplink bandwidth part are paired-configured to share the center frequency.

[0072] <Initial Access in NR>

[0073] In NR, a UE performs a cell search and a random access process to access a base station and communicate with the base station.

[0074] Cell search is a process in which a UE synchronizes with the cell of the corresponding base station using a Synchronization Signal Block (SSB) sent from the base station and obtains the physical layer cell ID and system information.

[0075] Figure 5An example of a synchronization signal block in a radio access technology to which embodiments of the present disclosure can be applied is shown.

[0076] Reference Figure 5 , SSB includes: the primary synchronization signal (PSS) and the secondary synchronization signal (SSS), which occupy one symbol and 127 subcarriers; and the PBCH, which spans three OFDM symbols and 240 subcarriers.

[0077] The UE monitors the SSB in the time domain and the frequency domain, thereby receiving the SSB.

[0078] SSB can be transmitted up to 64 times within 5 ms. Multiple SSBs are transmitted via different transmission beams within 5 ms, and the UE performs detection based on the specific beam used for transmission, assuming that SSBs are transmitted every 20 ms. As the frequency band increases, the number of beams used for SSB transmission within 5 ms may increase. For example, up to 4 SSB beams can be transmitted in a frequency band of 3 GHz or less, and up to 8 SSB beams can be transmitted in a frequency band of 3 GHz to 6 GHz. In addition, SSB can be transmitted using up to 64 different beams in a frequency band of 6 GHz or higher.

[0079] One slot includes two SSBs, and the start symbol and the number of repetitions in the slot are determined according to the subcarrier spacing as described below.

[0080] Unlike SS in the existing LTE system, SSB is not sent at the center frequency of the carrier bandwidth. That is, SSB can also be sent at a frequency other than the center of the system band, and when wideband operation is supported, multiple SSBs can be sent in the frequency domain. Therefore, the UE monitors SSB using a synchronization grid, which is a candidate frequency position for monitoring SSB. The carrier grid and synchronization grid, which are the center frequency position information of the channel for initial connection, are newly defined in NR, and since the frequency interval of the synchronization grid is configured to be wider than the carrier grid, the synchronization grid can support the UE's fast SSB search.

[0081] The UE can obtain the MIB on the PBCH of the SSB. The MIB (Master Information Block) includes the minimum information for the UE to receive the remaining minimum system information (RMSI) broadcast by the network. In addition, the PBCH may include information about the position of the first DM-RS symbol in the time domain, information for the UE to monitor SIB1 (for example, SIB1 parameter set information, information associated with SIB1CORESET, search space information, parameter information associated with PDCCH, etc.), offset information between common resource blocks and SSBs (the position of the absolute SSB in the carrier is sent via SIB1), etc. The SIB1 parameter set information is also applicable to some messages in the random access step of the UE accessing the base station after completing the cell search process. For example, the parameter set information of SIB1 can be applied to at least one of messages 1 to 4 for the random access process.

[0082] The above-mentioned RMSI may represent SIB1 (System Information Block 1), and SIB1 is broadcast periodically (e.g., 160ms) in the cell. SIB1 includes information required for the UE to perform the initial random access process, and SIB1 is periodically transmitted through the PDSCH. In order to receive SIB1, the UE must receive parameter set information for SIB1 transmission and CORESET (Control Resource Set) information for scheduling SIB1 through the PBCH. The UE uses the SI-RNTI in the CORESET to identify the scheduling information of SIB1. The UE obtains SIB1 on the PDSCH according to the scheduling information. The remaining SIBs except SIB1 may be transmitted periodically, or the remaining SIBs may be transmitted according to the request of the UE.

[0083] Figure 6 1 is a diagram for explaining a random access procedure in the radio access technology according to this embodiment.

[0084] refer to Figure 6 If the cell search is complete, the UE sends a random access preamble to the base station for random access. This random access preamble is sent via the PRACH. Specifically, the random access preamble is periodically sent to the base station via the PRACH, including continuous radio resources in repeated specific time slots. Generally, when a UE initially accesses a cell, a contention-based random access procedure is performed, and when performing random access for beam failure recovery (BFR), a non-contention-based random access procedure is performed.

[0085] The UE receives a random access response to the random access preamble sent. The random access response may include a random access preamble identifier (ID), an UL grant (uplink radio resources), a temporary C-RNTI (temporary cell radio network temporary identifier), and a TAC (time alignment command). Since a random access response may include random access response information for one or more UEs, a random access preamble identifier may be included to indicate the UE for which the included UL grant, temporary C-RNTI, and TAC are valid. The random access preamble identifier may be an identifier of a random access preamble received by a base station. The TAC may include information for adjusting uplink synchronization for the UE. The random access response may be indicated by a random access identifier (i.e., a random access radio network temporary identifier (RA-RNTI)) on the PDCCH.

[0086] After receiving a valid random access response, the UE processes the information included in the random access response and performs scheduled transmission to the base station. For example, the UE applies the TAC and stores the temporary C-RNTI. In addition, the UE transmits data stored in the UE's buffer or newly generated data to the base station using an UL grant. In this case, information for identifying the UE must be included in the data.

[0087] Finally, the UE receives a downlink message to resolve the contention.

[0088] <NR CORESET>

[0089] The downlink control channel in NR is transmitted in a CORESET (Control Resource Set) of 1 to 3 symbols in length, and the downlink control channel transmits uplink / downlink scheduling information, SFI (Slot Format Index), TPC (Transmit Power Control) information, etc.

[0090] As mentioned above, NR has introduced the concept of CORESET to ensure system flexibility. CORESET (Control Resource Set) refers to the time-frequency resources used for downlink control signals. The UE can use one or more search spaces in the CORESET time-frequency resources to decode control channel candidates. The CORESET-specific QCL (quasi-co-location) assumption is configured and used to provide information about the characteristics of the simulated beam direction as well as delay spread, Doppler spread, Doppler shift, and average delay, which are all characteristics assumed by existing QCL.

[0091] Figure 7 A CORESET is shown.

[0092] Reference Figure 7, a CORESET can exist in various forms within the carrier bandwidth in a single time slot, and a CORESET can include up to 3 OFDM symbols in the time domain. In addition, a CORESET is defined as a multiple of six resource blocks up to the carrier bandwidth in the frequency domain.

[0093] The first CORESET is designated (e.g., indicated, allocated) as part of the initial bandwidth portion through the MIB to receive additional configuration information and system information from the network. After establishing a connection with the base station, the UE can receive and configure one or more CORESET information through RRC signaling.

[0094] In this specification, frequency, frame, subframe, resource, resource block, area, frequency band, subband, control channel, data channel, synchronization signal, various reference signals, various signals related to NR (New Radio), or various messages may be interpreted as meanings currently or in the past, or various meanings to be used in the future.

[0095] In addition, in this specification, a bandwidth configured as a predetermined frequency portion in a carrier bandwidth is described as a bandwidth portion or BWP, but the present disclosure is not limited to such terminology. In addition, although a bandwidth configured as a predetermined frequency portion in a bandwidth portion is described as a sub-band, the present disclosure is not limited to this terminology.

[0096] In addition, the term "subband configuration information" below refers to any of the multiple pieces of information required to configure subbands, but is not limited to this term. Various terms that can express the same meaning may be used to describe and describe the information. Similarly, "LBT operation configuration information" refers to the information required for a UE to perform LBT. Terms expressing the same meaning may be used interchangeably without limitation.

[0097] Furthermore, for ease of description, LBT (Listen Before Talk) is used as an example to describe a technology for coexistence of wireless communication technologies in unlicensed bands. However, the present disclosure is applicable to various other coexistence technologies. Of course, the present disclosure is applicable not only to next-generation wireless communication technologies such as 5G or NR, but also to various wireless communication technologies such as 4G and Wi-Fi.

[0098] NR (New Radio)

[0099] Compared to LTE / LTE-Advanced, NR not only needs to provide higher data rates but must also meet the various QoS requirements for each detailed and specific use case. In particular, enhanced mobile broadband (eMBB), massive machine-type communications (mMTC), and ultra-reliable and low-latency communications (URLLC) are defined as representative use cases for NR. To meet the requirements of each use case, NR needs to be designed with a more flexible frame structure compared to LTE / LTE-Advanced.

[0100] Since each use case has different requirements for data rate, latency, coverage, etc., a method for effectively multiplexing radio resource units based on different parameter sets (for example, subcarrier spacing (SCS), subframe, transmission time interval (TTI), etc.) is needed as a solution to effectively meet the requirements according to the use scenario on the frequency band provided by the NR system.

[0101] To this end, the following discussions have been conducted: i) a digital method of multiplexing subcarrier spacing (SCS) values ​​different from each other based on TDM, FDM or TDM / FDM on one NR carrier; and ii) a method of supporting one or more time units when configuring a scheduling unit in the time domain. In this regard, in NR, a definition of a subframe has been given as a type of time domain structure. In addition, as a reference parameter set for defining the duration of the corresponding subframe, like LTE, a single subframe duration is defined as 14 OFDM symbols with normal CP overhead based on a 15kHz subcarrier spacing (SCS). Therefore, the subframe of NR has a duration of 1ms. Unlike LTE, since the subframe of NR is an absolute reference duration, time slots and mini-slots can be defined as time units for actual UL / DL data scheduling. In this case, regardless of the parameter set, the value of the number y of OFDM symbols constituting the time slot is defined as y=14.

[0102] Therefore, a slot may consist of 14 symbols. Depending on the transmission direction of the corresponding slot, all symbols may be used for DL ​​transmission or UL transmission, or the symbols may be used in a configuration of DL part + slot + UL part.

[0103] Furthermore, a mini-slot is defined as consisting of fewer symbols than a slot in a parameter set (or SCS), so a short time-domain scheduling interval can be configured for UL / DL data transmission or reception based on a mini-slot. Furthermore, a long scheduling interval can be configured for UL / DL data transmission or reception via slot aggregation.

[0104] Specifically, in the case of transmitting or receiving latency-critical data such as URLLC, it may be difficult to meet latency requirements when scheduling is performed on a time slot basis based on 1 ms (14 symbols) defined based on a parameter set with a small SCS value (e.g., 15 kHz) in the frame structure. To this end, a small slot consisting of fewer OFDM symbols than the time slot can be defined, so that scheduling of latency-critical data such as URLLC can be performed based on the small slot.

[0105] As described above, it is also possible to consider scheduling data according to the latency requirement based on the length of the time slot (or mini-slot) defined by the parameter set by supporting parameter sets with different SCS values ​​in one NR carrier and multiplexing them in a TDM and / or FDM manner. Figure 12 As shown in FIG, when the SCS is 60 kHz, the symbol length is reduced to about 1 / 4 of the symbol length of the SCS 15 kHz. Therefore, when a time slot consists of 14 OFDM symbols, the time slot length based on 15 kHz is 1 ms, while the time slot length based on 60 kHz is reduced to about 0.25 ms.

[0106] Therefore, since different SCSs or different TTI lengths are defined in NR, technologies for meeting the requirements of each of URLLC and eMBB have been developed.

[0107] PDCCH

[0108] NR and LTE / LTE-A systems transmit and receive L1 control information, such as downlink (DL) assignments, downlink control information (DCI), and uplink (UL) grant DCI, through PDCCH. Control channel elements (CCEs) are defined as resource units for transmitting PDCCH. In NR, a control resource set (CORESET) is a frequency / time resource for transmitting PDCCH and can be set in each UE. Furthermore, each CORESET can be composed of one or more search spaces for the UE to monitor PDCCH, and the search space is composed of one or more PDCCH candidates.

[0109] Physics Resources

[0110] Compared to LTE, the physical resources used for NR can be flexibly configured. Common resource blocks (CRBs) are defined from point A, which serves as the reference point for the frequency radio resource unit of any NR cell. The BWP configuration for any UE transmission and reception is based on the CRB. In addition, when multiple SCSs are supported in any cell, they can also be configured for a specific carrier bandwidth for each subcarrier spacing. In addition, PRBs and VRBs are configured for each BWP configured for any UE as the unit for allocating radio resources to the UE.

[0111] For details on the NR physical resource configuration method, please refer to the 3GPP TS 38.211 document.

[0112] Wider bandwidth operation

[0113] Typical LTE systems support scalable bandwidth operation for any LTE CC (component carrier). That is, depending on the frequency deployment scenario, LTE providers can configure a bandwidth ranging from a minimum of 1.4 MHz to a maximum of 20 MHz when configuring a single LTE CC, and a typical LTE UE supports transmission / reception capabilities of 20 MHz bandwidth for a single LTE CC.

[0114] However, NR is designed to support UEs with different transmit / receive bandwidth capabilities on a single wideband NR CC. Figure 9 As shown, one or more bandwidth parts (BWPs) including subdivided bandwidths need to be configured for the NR CC, thereby supporting flexible and wider bandwidth operation by configuring and activating different bandwidth parts for each UE.

[0115] Specifically, one or more bandwidth parts may be configured by a single serving cell configured for a UE in NR, and the UE is defined as activating one downlink (DL) bandwidth part and one uplink (UL) bandwidth part to use for uplink / downlink data transmission / reception in the corresponding serving cell. In addition, in the case where multiple serving cells are configured for the UE (i.e., a UE to which CA is applied), the UE is further defined as activating one downlink bandwidth part and / or one uplink bandwidth part in each serving cell to use for uplink / downlink data transmission / reception by utilizing the radio resources of the corresponding serving cell.

[0116] Specifically, an initial bandwidth part for the initial access process of the UE can be defined in the serving cell; one or more UE-specific bandwidth parts can be configured for each UE through dedicated RRC signaling, and a default bandwidth part for fallback operation can be defined for each UE.

[0117] The simultaneous activation and use of multiple downlink and / or uplink bandwidth parts may be defined based on the capabilities of the UE and the configuration of bandwidth parts in the serving cell. However, NR rel-15 defines the activation and use of only one downlink ("DL") bandwidth part and one uplink ("UL") bandwidth part at a time.

[0118] NR-U (NR-Unlicensed Spectrum)

[0119] Unlike licensed bands, unlicensed bands are wireless channels that are permitted for use by any provider or individual to provide wireless communication services within the regulatory framework of their respective countries / regions, rather than being used exclusively by a specific provider. Consequently, there are challenges to be addressed: i) coexistence with various short-range wireless communication protocols (e.g., Wi-Fi, Bluetooth, NFC, etc.) provided via unlicensed bands, and ii) coexistence between NR providers and LTE providers when providing NR services via these unlicensed bands.

[0120] Therefore, when providing NR services through unlicensed frequency bands, in order to avoid interference or conflict between various wireless communication services, it is necessary to support a wireless channel access scheme based on LBT (Listen Before Talk). In the wireless channel access scheme based on LBT, the power level of the wireless channel or carrier is sensed before sending the radio signal to determine whether the wireless channel or carrier is available. In this case, if a specific wireless channel or carrier of the unlicensed frequency band is used by other wireless communication protocols or other providers, the NR service through the corresponding frequency band will be limited, so that the QoS requested by the user may not be guaranteed in the wireless communication service through the unlicensed frequency band compared to the wireless communication service through the licensed frequency band.

[0121] In addition, when some broadband NR-U cells are configured in unlicensed bands, coexistence with other RATs needs to be considered to increase the access probability of the NR-U cells. In this case, the DL or ULBWP configured for any UE in the NR-U cell or the system bandwidth of the NR-U cell is divided into sub-bands, LBT is performed in units of corresponding sub-bands, and a wireless protocol needs to be designed for radio signal transmission in units of sub-bands.

[0122] In the present disclosure, the frequency bandwidth as a unit of LBT for transmission by a base station or UE in an NR-U cell is referred to as a sub-band, but the present disclosure is not limited to this name. For example, the frequency bandwidth in units of LBT may be referred to as other names, such as LBT bandwidth or channel access bandwidth. In addition, in the following disclosure, any value is "signaled by a base station", "configured by base station signaling" or "signaled from a base station" means that the corresponding value is configured by UE-specific or UE group common or cell-specific RRC signaling, MAC control element signaling (MAC CE signaling) or physical layer control signaling (L1 control signaling).

[0123] Hereinafter, a method for transmitting and receiving data in an unlicensed band will be described in detail with reference to the accompanying drawings.

[0124] Figure 10 is a diagram illustrating a process of receiving downlink data and transmitting uplink data in an unlicensed band by a UE according to an embodiment.

[0125] Reference Figure 10 , the UE may receive configuration information including parameters for configuring a plurality of resource block sets in an unlicensed band (S1000).

[0126] In NR, a bandwidth part (BWP) can be configured for each UE to transmit and receive uplink or downlink radio physical channels and physical signals for the UE. The UE can activate one BWP in the configured bandwidth part and transmit and receive data. Since a bandwidth of 100 MHz or more can be used as the system bandwidth constituting an NR cell, the bandwidth of a BWP for any UE can also be configured to be a bandwidth of 100 MHz or more.

[0127] At the same time, in order for any node to transmit a radio signal in an unlicensed frequency band, LBT is first performed to confirm whether the corresponding radio channel is occupied by another node. Therefore, in order to transmit PDSCH for a UE in an NR-U cell in an unlicensed frequency band, the base station performs LBT in the frequency band configured for the corresponding NR-U cell. If the corresponding frequency band is empty, PDCCH can be performed to perform PDSCH transmission. Similarly, in order for the UE to perform uplink signal transmission, LBT needs to be performed on the corresponding uplink radio channel first.

[0128] The NR-U cell can be configured for data transmission and reception in an unlicensed band. In this case, the system bandwidth of the cell can be configured to be greater than 20 MHz. In addition, when the bandwidth portion is configured in the NR-U cell, the bandwidth of the DLBWP or UL BWP for the UE can also be configured to be greater than 20 MHz. In this case, if LBT is performed in units of BWP and data transmission and reception are performed, the competitiveness in terms of channel access probability may be significantly reduced compared to other radio access technologies (RATs) (such as Wi-Fi) that perform LBT in units of 20 MHz. Therefore, it is necessary to increase the channel access probability by configuring one or more sub-bands with arbitrary bandwidth for the system bandwidth or BWP of the NR-U cell.

[0129] In the present disclosure, a subband is composed of a predetermined number of resource blocks corresponding to the bandwidth and may also be referred to as a resource block set. However, this term is used as an example and is not limited to a specific term, as long as it corresponds to a frequency band composed of multiple resource blocks to which the technical concept of the present disclosure can be applied.

[0130] According to the embodiment, the configuration of resource block sets (i.e., subbands) can be configured in units of the DL BWP or UL BWP configured for the UE. For the BWP configured for the UE, the subbands can be implicitly configured based on the configuration information of each BWP. For example, the multiple subbands constituting each BWP can be configured based on the frequency resource allocation information and subcarrier spacing (SCS) value configured for each BWP.

[0131] That is, the configuration information including parameters for configuring multiple resource block sets in the unlicensed band may include guard band configuration information for configuring at least one guard band in the unlicensed band. The guard band configuration information may include SCS information for the bandwidth portion configured in the unlicensed band. In this case, the guard band configuration information may include SCS information for each of the at least one bandwidth portion configured for the UE in the unlicensed band. Alternatively, the guard band configuration information may also include bandwidth portion size information.

[0132] Each bandwidth part configured for a UE may be composed of multiple sub-bands and at least one guard band configured between each sub-band to distinguish each sub-band. Therefore, the number of guard bands included in a bandwidth part is one less than the number of sub-bands included in the same bandwidth.

[0133] According to an embodiment, the resource blocks (PRBs) constituting each of the at least one guard band may be determined based on the SCS information of the bandwidth portion including the guard band. Alternatively, the resource block set and the resource blocks constituting the guard band may be determined based on the SCS information of the bandwidth portion and the size information of the bandwidth portion.

[0134] If the number of resource blocks constituting a subband determined based on the SCS information and bandwidth part size information of the bandwidth part is N, each of the plurality of subbands may be composed of N resource blocks. Furthermore, if the number of resource blocks constituting a guard band determined based on the SCS information and bandwidth part size information of the bandwidth part is M, each of the at least one guard band may be composed of M resource blocks.

[0135] In this case, according to an example, multiple sub-bands for each bandwidth part can be sequentially configured starting from the lowest resource block constituting the corresponding bandwidth part. That is, the lowest sub-band in the corresponding bandwidth part can be composed of N resource blocks from resource block #0 to resource block #(N-1). Therefore, the lowest guard band in the corresponding bandwidth part can be composed of M resource blocks from block #N to #(N+M-1).

[0136] A sub-band consisting of N resource blocks and a guard band consisting of M resource blocks are alternately configured, and the last sub-band of the corresponding bandwidth part may be composed of N or less than N resource blocks.

[0137] As an example, the plurality of sub-bands constituting the bandwidth portion may include a lowest sub-band and an upper sub-band consisting of a number of resource blocks less than N as described above. That is, sub-bands other than the two sub-bands located at the upper and lower edges of the bandwidth portion may consist of N resource blocks.

[0138] According to an example, the number of resource blocks for each of the multiple sub-bands constituting the bandwidth portion can be configured via base station signaling. That is, the configuration information can include the number of resource blocks constituting the multiple sub-bands. Furthermore, the number of resource blocks constituting the guard band can also be configured via base station signaling.

[0139] Alternatively, the number of resource blocks constituting the guard band and the index of the starting resource block which is the lowest resource block among the resource blocks constituting each guard band are configured by signaling of the base station, whereby the subband can be configured between the guard bands.

[0140] According to another example, the subband configuration can be configured in units of the system bandwidth with which the corresponding NR-U cell is configured, or in units of the carrier bandwidth of each parameter set, regardless of the bandwidth portion configured for any UE. For example, the subband configuration can be configured based on a common resource block (CRB) from point A of the system bandwidth.

[0141] In this case, the guard band configuration information may include SCS information of the system bandwidth configured in the unlicensed band. Alternatively, the guard band configuration information may also include information about the system bandwidth size. Alternatively, according to another example, the guard band configuration information may include subcarrier spacing information of a subcarrier spacing-specific (SCS-specific) carrier bandwidth. Alternatively, the guard band configuration information may also include information about the size of the corresponding bandwidth.

[0142] According to an embodiment, the common resource blocks constituting each of the at least one guard bands may be determined based on the SCS information of the system bandwidth. Alternatively, the common resource blocks constituting each of the at least one guard bands may be determined based on the SCS information of the system bandwidth and the size of the system bandwidth.

[0143] If the number of common resource blocks constituting a subband determined based on the SCS information of the system bandwidth is set to R, each of the multiple subbands may be composed of R common resource blocks. In addition, if the number of common resource blocks constituting a guard band determined based on the SCS information of the system bandwidth is S, each of the at least one guard band may be composed of S common resource blocks.

[0144] In this case, according to an embodiment, multiple sub-bands for the system bandwidth may be sequentially configured starting from the lowest resource block corresponding to point A. That is, the lowest sub-band in the corresponding system bandwidth may consist of R resource blocks from resource block #0 to resource block #(R-1). Therefore, the lowest guard band in the corresponding system bandwidth may consist of S resource blocks from block #R to #(R+S-1).

[0145] A sub-band consisting of R resource blocks and a guard band consisting of S resource blocks are alternately configured, and the last sub-band in the corresponding system bandwidth may consist of R resource blocks or fewer than R resource blocks.

[0146] As an example, the multiple subbands constituting the system bandwidth may include a lowest subband and an upper subband configured with fewer resource blocks than the above R. That is, the subbands other than the two subbands located at the upper and lower edges of the system bandwidth may be composed of R resource blocks.

[0147] Alternatively, according to an embodiment, the number of resource blocks for each of the multiple sub-bands comprising the system bandwidth may be configured via base station signaling. That is, the configuration information may include the number of resource blocks comprising the multiple sub-bands. Furthermore, the number of resource blocks comprising the guard band may also be configured via base station signaling.

[0148] Alternatively, the number of common resource blocks constituting the guard band and the index of the starting common resource block, which is the lowest common resource block among the common resource blocks constituting each guard band, can be configured via base station signaling. That is, the starting common resource block and the number of resource blocks for at least one guard band within the system bandwidth can be indicated via RRC signaling, etc. Therefore, multiple sub-bands can be configured between each guard band.

[0149] According to another embodiment, the resource blocks constituting each of the at least one guard bands may be determined based on the SCS information of the SCS specific carrier bandwidth. Alternatively, the resource blocks constituting each of the at least one guard bands may be determined based on the SCS information of the SCS specific carrier bandwidth and the size of the SCS specific carrier bandwidth.

[0150] If the number of resource blocks constituting a subband determined based on the SCS information of the SCS specific carrier bandwidth is set to P, each of the multiple subbands may be composed of P resource blocks. In addition, if the number of resource blocks constituting a guard band determined based on the SCS information of the SCS specific carrier bandwidth is Q, each of the at least one guard band may be composed of Q resource blocks.

[0151] In this case, according to an example, multiple sub-bands for the SCS specific carrier bandwidth can be sequentially configured starting from the lowest resource block of the corresponding bandwidth. That is, the lowest sub-band in the corresponding SCS specific carrier bandwidth can be composed of P resource blocks from resource block #0 to resource block #(P-1). Therefore, the lowest guard band in the corresponding SCS specific carrier bandwidth can be composed of Q resource blocks from block #P to #(P+Q-1).

[0152] A sub-band consisting of P resource blocks and a guard band consisting of Q resource blocks are alternately configured, and the last sub-band in the corresponding system bandwidth may be composed of P or less than P resource blocks.

[0153] As an example, the multiple subbands constituting the SCS specific carrier bandwidth may include a lowest subband and a highest subband consisting of fewer resource blocks than the above P. That is, the subbands other than the two subbands located at the upper and lower edges of the SCS specific carrier bandwidth may be configured as P resource blocks.

[0154] Alternatively, according to an embodiment, the number of resource blocks for each of the multiple sub-bands comprising the SCS specific carrier bandwidth may be configured via base station signaling. That is, the configuration information may include the number of resource blocks comprising the multiple sub-bands. Furthermore, the number of resource blocks comprising the guard band may also be configured via base station signaling.

[0155] Alternatively, the number of resource blocks constituting the guard band and the index of the starting resource block, which is the lowest resource block among the resource blocks constituting each guard band, can be configured through base station signaling. That is, the starting resource block within the SCS specific carrier bandwidth and the number of resource blocks in at least one guard band can be indicated through RRC signaling, etc. Therefore, multiple sub-bands can be configured between each guard band.

[0156] However, in the above example, the number of resource blocks (N, M, R, S, P, Q values) constituting each subband and each guard band can be configured to be the same or different for each subband or guard band. In addition, when there are multiple possible methods for configuring subbands, the base station can indicate to the UE the method for configuring the subband to be applied.

[0157] Return Reference Figure 10 , the UE may confirm multiple resource block sets based on the configuration information (S1010).

[0158] When multiple sub-bands are configured based on the SCS information for the bandwidth portion configured for the UE, the UE can obtain the SCS information for the bandwidth portion included in the configuration information. The UE can confirm the number of resource blocks constituting the sub-band or guard band based on the corresponding SCS information. Therefore, the UE can configure multiple sub-bands for the activated bandwidth portion based on the corresponding number.

[0159] This may also apply even when the number of resource blocks constituting a subband or a guard band is determined based on SCS information of the system bandwidth or the SCS-specific carrier bandwidth.

[0160] When the number of resource blocks constituting a subband or a guard band and the index of a starting resource block are configured by signaling of the base station, the UE can confirm each of the resource blocks constituting the subband and the guard band included in the configuration information.

[0161] Return Reference Figure 10 , the UE may transmit / receive data to / from the base station through at least one resource block set determined based on a result of performing listen-before-talk (LBT) on each of a plurality of resource block sets received from the base station (S1020).

[0162] As described above, when multiple subbands are configured for any of the bandwidth parts, system bandwidth, or SCS-specific carrier bandwidth, the base station can perform LBT on a per-subband basis. That is, in this disclosure, a subband can represent the LBT bandwidth corresponding to the unit for performing LBT on the frequency axis. Therefore, resource allocation for DL ​​BWPs and PDCCH or PDSCH transmission and reception can be performed on a per-subband basis.

[0163] The base station can perform LBT on each of the multiple sub-bands and configure a bitmap indicating the LBT execution result. That is, the base station can send the LBT result (e.g., success / failure) for each sub-band for downlink transmission to the UE via the UE-group common PDCCH. The UE can receive downlink control information including the corresponding bitmap from the base station.

[0164] In this case, the size of the bitmap may be determined based on the number of sub-bands. For example, it is assumed that the bitmap constituting the UE group common DCI consists of L bits.

[0165] When multiple sub-bands are configured for a bandwidth portion, the L value can be determined by the number of sub-bands (k value) that constitute the corresponding BWP for each BWP configured for the UE. For example, the LBT result for each sub-band can be indicated in a 1:1 correspondence with the bits of the corresponding bitmap. That is, it can be determined as L = k.

[0166] When multiple subbands are configured for the system bandwidth, the L value can be determined by the number of subbands (m value) that constitute the system bandwidth starting from point A. For example, the LBT result for each subband can be indicated in a 1:1 correspondence with the bits of the corresponding bitmap. That is, it can be determined as L = m.

[0167] When multiple subbands are configured for an SCS specific carrier bandwidth, the value of L can be determined by the number n of subbands that constitute the SCS specific carrier bandwidth. For example, the LBT result for each subband can be indicated in a 1:1 correspondence with the bits in the corresponding bitmap. That is, L can be determined as n.

[0168] Alternatively, according to another embodiment, the bitmap size, L value, and position information of bits corresponding to multiple sub-bands configured for the UE configured through the corresponding UE group common DCI may all be signaled by the base station.

[0169] The UE may receive scheduling information of at least one sub-band resource determined based on the LBT execution result from the base station, and may receive downlink data from the base station or transmit uplink data to the base station according to the corresponding scheduling information.

[0170] According to one embodiment, it is assumed that resources for data transmission and reception are allocated in a frequency band that includes one of at least one guard band and two resource block sets, with one of the multiple resource block sets separated by a guard band. That is, resource allocation for data transmission and reception can be performed in a band that includes two sub-frequency bands and a guard band therebetween. In this case, the UE can only receive data from or transmit data to the base station in the frequency band if LBT is successful for both resource block sets. That is, data is only transmitted and received in the corresponding frequency band if LBT is successful for both resource block sets, with the guard band between them.

[0171] According to the above embodiments, a method and apparatus for configuring one or more sub-bands in an unlicensed frequency band and transmitting and receiving data based on the LBT results of the configured one or more sub-bands can be provided. This allows the UE to prevent the reduction in data transmission probability that may occur when performing LBT in a wideband area and to meet the data transmission QoS requirements using the unlicensed frequency band.

[0172] Hereinafter, operations of a base station related to the above-mentioned UE operations will be described with reference to the accompanying drawings.

[0173] Figure 11 is a diagram illustrating a process of transmitting downlink data and receiving uplink data in an unlicensed frequency band by a base station according to an embodiment.

[0174] Reference Figure 11 , the base station may send configuration information including parameters for configuring a plurality of resource block sets in an unlicensed frequency band (S1100).

[0175] According to the embodiment, the configuration of resource block sets (i.e., subbands) can be configured in units of the DL BWP or UL BWP configured for the UE. For the BWP configured for the UE, the subbands can be implicitly configured based on the configuration information of each BWP. For example, the multiple subbands constituting each BWP can be configured based on the frequency resource allocation information and subcarrier spacing (SCS) value configured for each BWP.

[0176] That is, the configuration information including parameters for configuring multiple resource block sets in the unlicensed band may include guard band configuration information for configuring at least one guard band in the unlicensed band. The guard band configuration information may include SCS information for the bandwidth portion configured in the unlicensed band. In this case, the guard band configuration information may include SCS information for each of the at least one bandwidth portion configured for the UE in the unlicensed band. Alternatively, the guard band configuration information may also include bandwidth portion size information.

[0177] Each bandwidth part configured for a UE may be composed of multiple sub-bands and at least one guard band configured between each sub-band to distinguish each sub-band. Therefore, the number of guard bands included in a bandwidth part is one less than the number of sub-bands included in the same bandwidth.

[0178] According to an embodiment, the resource blocks (PRBs) constituting each of the at least one guard band may be determined based on the SCS information of the bandwidth portion including the guard band. Alternatively, the resource block set and the resource blocks constituting the guard band may be determined based on the SCS information of the bandwidth portion and the size information of the bandwidth portion.

[0179] If the number of resource blocks constituting a subband determined based on the SCS information and bandwidth part size information of the bandwidth part is N, each of the plurality of subbands may be composed of N resource blocks. Furthermore, if the number of resource blocks constituting a guard band determined based on the SCS information and bandwidth part size information of the bandwidth part is M, each of the at least one guard band may be composed of M resource blocks.

[0180] In this case, according to an embodiment, multiple sub-bands for each bandwidth part may be sequentially configured starting from the lowest resource block constituting the corresponding bandwidth part. That is, the lowest sub-band in the corresponding bandwidth part may consist of N resource blocks, from resource block #0 to resource block #(N-1). Therefore, the lowest guard band in the corresponding bandwidth part may consist of M resource blocks, from block #N to #(N+M-1).

[0181] A sub-band consisting of N resource blocks and a guard band consisting of M resource blocks are alternately configured, and the last sub-band of the corresponding bandwidth part may consist of N resource blocks or less than N resource blocks.

[0182] As an example, the plurality of subbands constituting the bandwidth portion may include the lowest subband and the highest subband consisting of resource blocks less than N as described above. That is, the subbands other than the two subbands located at the upper and lower edges of the bandwidth portion may consist of N resource blocks.

[0183] According to an embodiment, the number of resource blocks for each of the multiple sub-bands constituting the bandwidth portion may be configured via base station signaling. That is, the configuration information may include the number of resource blocks constituting the multiple sub-bands. Furthermore, the number of resource blocks constituting the guard band may also be configured via base station signaling.

[0184] Alternatively, the number of resource blocks constituting the guard band and the index of the starting resource block, which is the lowest resource block among the resource blocks constituting each guard band, are configured by signaling from the base station. Therefore, the sub-band can be configured between the guard bands.

[0185] According to another embodiment, the subband configuration may be configured in units of the system bandwidth with which the corresponding NR-U cell is configured, or in units of the carrier bandwidth of each parameter set, regardless of the bandwidth portion configured for any UE. For example, the subband configuration may be configured based on a common resource block (CRB) from point A of the system bandwidth.

[0186] In this case, the guard band configuration information may include SCS information of the system bandwidth configured in the unlicensed band. Alternatively, the guard band configuration information may also include information about the system bandwidth size. Alternatively, according to another embodiment, the guard band configuration information may include subcarrier spacing information of a subcarrier spacing-specific (SCS-specific) carrier bandwidth. Alternatively, the guard band configuration information may also include information about the size of the corresponding bandwidth.

[0187] According to an embodiment, the common resource blocks constituting each of the at least one guard bands may be determined based on the SCS information of the system bandwidth. Alternatively, the common resource blocks constituting each of the at least one guard bands may be determined based on the SCS information of the system bandwidth and the size of the system bandwidth.

[0188] If the number of common resource blocks constituting a subband determined based on the SCS information of the system bandwidth is set to R, each of the multiple subbands may be composed of R common resource blocks. In addition, if the number of common resource blocks constituting a guard band determined based on the SCS information of the system bandwidth is S, each of the at least one guard band may be composed of S common resource blocks.

[0189] In this case, according to an embodiment, multiple sub-bands for the system bandwidth may be sequentially configured starting from the lowest resource block corresponding to point A. That is, the lowest sub-band in the corresponding system bandwidth may consist of R resource blocks from resource block #0 to resource block #(R-1). Therefore, the lowest guard band in the corresponding system bandwidth may consist of S resource blocks from block #R to #(R+S-1).

[0190] A sub-band consisting of R resource blocks and a guard band consisting of S resource blocks are alternately configured, and the last sub-band in the corresponding system bandwidth may consist of R or less than R resource blocks.

[0191] As an example, the multiple subbands constituting the system bandwidth may include a lowest subband and an upper subband configured with fewer resource blocks than the above R. That is, the subbands other than the two subbands located at the upper and lower edges of the system bandwidth may be composed of R resource blocks.

[0192] Alternatively, according to an embodiment, the number of resource blocks constituting each sub-band of the system bandwidth may be configured via base station signaling. That is, the configuration information may include the number of resource blocks constituting multiple sub-bands. Furthermore, the number of resource blocks constituting the guard band may also be configured via base station signaling.

[0193] Alternatively, the number of common resource blocks constituting the guard band and the index of the starting common resource block, which is the lowest common resource block among the common resource blocks constituting each guard band, can be configured via base station signaling. That is, the starting common resource block and the number of resource blocks for at least one guard band within the system bandwidth can be indicated via RRC signaling, etc. Therefore, multiple sub-bands can be configured between each guard band.

[0194] According to another embodiment, the resource blocks constituting each of the at least one guard bands may be determined based on the SCS information of the SCS specific carrier bandwidth. Alternatively, the resource blocks constituting each of the at least one guard bands may be determined based on the SCS information of the SCS specific carrier bandwidth and the size of the SCS specific carrier bandwidth.

[0195] If the number of resource blocks constituting a subband determined based on the SCS information of the SCS specific carrier bandwidth is set to P, each of the multiple subbands may be composed of P resource blocks. In addition, if the number of resource blocks constituting a guard band determined based on the SCS information of the SCS specific carrier bandwidth is Q, each of the at least one guard band may be composed of Q resource blocks.

[0196] In this case, according to an example, multiple sub-bands for the SCS specific carrier bandwidth can be sequentially configured starting from the lowest resource block of the corresponding bandwidth. That is, the lowest sub-band in the corresponding SCS specific carrier bandwidth can be composed of P resource blocks from resource block #0 to resource block #(P-1). Therefore, the lowest guard band in the corresponding SCS specific carrier bandwidth can be composed of Q resource blocks from block #P to #(P+Q-1).

[0197] A sub-band consisting of P resource blocks and a guard band consisting of Q resource blocks are alternately configured, and the last sub-band in the corresponding system bandwidth may be composed of P or less than P resource blocks.

[0198] As an example, the multiple subbands constituting the SCS specific carrier bandwidth may include a lowest subband and a highest subband consisting of fewer resource blocks than the above P. That is, the subbands other than the two subbands located at the upper and lower edges of the SCS specific carrier bandwidth may be configured as P resource blocks.

[0199] Alternatively, depending on the embodiment, the number of resource blocks for each sub-band constituting the SCS specific carrier bandwidth may be configured via base station signaling. That is, the configuration information may include the number of resource blocks constituting multiple sub-bands. Furthermore, the number of resource blocks constituting the guard band may also be configured via base station signaling.

[0200] Alternatively, the number of resource blocks constituting the guard bands and the index of the starting resource block, which is the lowest resource block among the resource blocks constituting each guard band, can be configured via base station signaling. Specifically, the starting resource block within the SCS specific carrier bandwidth and the number of resource blocks in at least one guard band can be indicated via RRC signaling, etc. Consequently, multiple subbands can be configured between each guard band.

[0201] Return Reference Figure 11 The base station may send a result of performing listen-before-talk (LBT) on each of the plurality of resource block sets to the user equipment (S1110).

[0202] As described above, when multiple sub-bands are configured for any of the bandwidth part, system bandwidth, or SCS-specific carrier bandwidth, the base station can perform LBT in units of the corresponding sub-bands. That is, in the present disclosure, the sub-band can represent the LBT bandwidth corresponding to the unit for performing LBT on the frequency axis.

[0203] As mentioned above, in order to transmit a radio signal from any node in an unlicensed frequency band, the LBT process for confirming whether the radio channel is occupied by another node can be performed first. Therefore, in order to transmit PDSCH for a UE in an NR-U cell in an unlicensed frequency band configured by a certain NR base station, the base station must perform LBT on the frequency band configured for the NR-U cell. As a result of performing LBT, when the wireless channel in the unlicensed frequency band is empty, the base station can send PDCCH and PDSCH to the UE accordingly.

[0204] For example, the base station may perform LBT for each of the multiple sub-bands and configure a bitmap indicating the LBT execution result. That is, the base station may send the LBT result (e.g., success / failure) for each sub-band used for downlink transmission to the UE via the UE group-common PDCCH. The UE may receive downlink control information including the corresponding bitmap from the base station.

[0205] In this case, the size of the bitmap may be determined based on the number of the plurality of sub-bands. For example, it is assumed that the bitmap constituting the UE group common DCI consists of L bits.

[0206] When multiple sub-bands are configured for a bandwidth portion, the L value can be determined by the number of sub-bands (k value) that constitute the corresponding BWP for each BWP configured for the UE. For example, the LBT result for each sub-band can be indicated in a 1:1 correspondence with the bits of the corresponding bitmap. That is, it can be determined as L = k.

[0207] When multiple subbands are configured for the system bandwidth, the L value can be determined by the number of subbands (m value) that constitute the system bandwidth starting from point A. For example, the LBT result for each subband can be indicated in a 1:1 correspondence with the bits of the corresponding bitmap. That is, it can be determined as L = m.

[0208] When multiple subbands are configured for an SCS specific carrier bandwidth, the value of L can be determined by the number n of subbands that constitute the SCS specific carrier bandwidth. For example, the LBT result for each subband can be indicated in a 1:1 correspondence with the bits in the corresponding bitmap. That is, L can be determined as n.

[0209] Alternatively, according to another embodiment, the bitmap size and L value configured through the corresponding UE group common DCI and the position information of the bits corresponding to the multiple sub-bands configured for the UE may all be signaled by the base station.

[0210] Return Reference Figure 11 , the base station may transmit / receive data to / from the user equipment through at least one resource block set determined based on a result of performing the LBT (S1120).

[0211] The base station may send scheduling information for at least one sub-band resource determined based on the LBT execution result of the base station to the UE. In other words, the base station may send downlink data via at least one sub-band in which the LBT operation is successful. The base station may send downlink data to the UE based on the corresponding scheduling information.

[0212] According to the above embodiments, a method and apparatus for configuring one or more sub-bands in an unlicensed frequency band and transmitting and receiving data based on the LBT results of the configured one or more sub-bands can be provided. This allows the UE to prevent the reduction in data transmission probability that may occur when performing LBT in a wideband area and to meet the data transmission QoS requirements using the unlicensed frequency band.

[0213] The operations of the UE and the base station described above are merely illustrative of some embodiments according to the present disclosure, and various other embodiments may be performed in corresponding operations and steps.

[0214] In addition, although the above description is based on downlink transmission of the base station, it can be substantially applied to uplink transmission of the UE as long as it does not violate the technical concept.

[0215] In this case, when uplink is transmitted in an unlicensed band in NR, an embodiment of performing LBT by the UE will be described in detail below.

[0216] In order for the UE to perform uplink signal transmission, the UE needs to prioritize LBT on the uplink radio channel. Therefore, when sending PUSCH, the UE needs to prioritize LBT for uplink data transmission. The UE may not send the scheduling control information received from the base station, that is, it may not send the corresponding PUSCH at the time indicated by the UL grant (UL grant) DCI format, depending on whether the corresponding LBT is successful. In other words, when LBT fails, the PUSCH transmission of the corresponding UL grant may fail.

[0217] For example, in NR, for the HARQ ACK / NACK feedback timing of the UE's PDSCH reception, the base station can configure it through RRC signaling, or indicate it to the corresponding UE through downlink allocation DCI (DL allocation DCI). However, in the case of the above-mentioned NR-U cell in the unlicensed frequency band, according to the LBT result of the UE, it may not be possible to send the PUCCH containing the HARQ ACK / NACK feedback information at the time indicated by the base station. In other words, the failure of LBT, that is, the situation where the corresponding wireless channel is occupied by another node, is the result of LBT, and the UE fails to send the HARQ ACK / NACK feedback information according to the PDSCH reception at the time indicated by the base station. This defect may seriously degrade the HARQ performance in the NR-U cell.

[0218] Figure 12 It is a diagram for explaining LBT for wireless communication in an unlicensed band according to an embodiment of the present disclosure. For example, it can be defined that the base station instructs the UE to perform LBT (listen before talking) when allocating PUCCH transmission resources or PUSCH transmission resources to the UE, or when the corresponding PUCCH transmission or PUSCH transmission occurs. The UE can send UCI (uplink control information), such as HARQ ACK / NACK feedback information or CQI / CSI report information, to the base station via PUCCH or PUSCH. In this regard, in NR, time resources and frequency resources are PUCCH resources for transmitting HARQ feedback, which can be indicated by the base station through uplink allocation DCI or uplink authorization DCI. Alternatively, the PUCCH resources for transmitting HARQ feedback can be semi-statically configured through RRC signaling. Specifically, in the case of time resources, the timing gap value between the PDSCH reception time slot and the corresponding HARQ feedback information transmission time slot can be sent to the UE through DL allocation DCI or RRC signaling.

[0219] PUCCH resources for CQI / CSI reporting may also be allocated to the UE via DL allocation DCI or RRC signaling.

[0220] Reference Figure 12 , hatching indicates that downlink transmission is performed via the unlicensed band at a later time point when downlink LBT (DL LBT) for downlink transmission in the base station is successful. For example, downlink transmission may be transmission of a downlink channel or transmission of a downlink signal indicating uplink transmission. For example, downlink transmission DL and uplink transmission UL may correspond to i) PDSCH transmission and PUCCH transmission for HARQ for feedback thereto, ii) DCI for requesting CQI / CSI reporting and PUCCH for its reporting, or iii) DCI for transmitting PUSCH and uplink scheduling information for PUSCH transmission. In this case, a time gap occurs between downlink transmission DL and uplink transmission UL.

[0221] For example, when a downlink signal or downlink channel transmitted in a downlink indicates PUCCH transmission in an NR-U cell in an unlicensed frequency band, the UE prioritizes listen-before-talk (LBT) for PUCCH transmission in accordance with the provisions of the unlicensed spectrum, and decides whether to transmit PUCCH based on the point indicated by the LBT result. If the corresponding wireless channel is occupied by another node as a result of the LBT, that is, if an LBT failure occurs, the corresponding UE may not be able to perform PUCCH transmission at the indicated time.

[0222] However, if the channel occupation time (COT) of the base station includes a DL-allocated DCI transmission time slot containing PUCCH resource allocation information and PUCCH transmission indication information, or a PDSCH transmission time slot according to the corresponding DL-allocated DCI, and its PUCCH transmission time slot, PUCCH transmission can be performed in the corresponding UE without performing LBT. This is because the unlicensed frequency band has been used by the base station for downlink transmission to the UE and is not occupied by other nodes. That is, according to the configuration of the COT and the value of the time gap value K1 between the base station's PDSCH reception time slot and the corresponding HARQ feedback information transmission time slot, HARQ feedback transmission on the PUCCH is possible without performing listen-before-talk (LBT) at the corresponding UE.

[0223] Similarly, it can be assumed that the time gap value between i) the time slot to which the DL allocation DCI is transmitted and ii) the time slot in which the PUCCH including the CQI / CSI reporting information is transmitted is M. When the CSI / CQI reported through the PUCCH is indicated by the DL allocation DCI, according to the configuration of the COT and the M value of the base station, CQI / CSI reporting on the PUCCH is possible when the corresponding UE does not require LBT.

[0224] Similar to the case of PUCCH, it can be assumed that the time gap value between i) the time slot in which the UL grant DCI is transmitted and ii) the time slot in which the PUSCH is transmitted is K2. The value of the time gap K2 can be semi-statically configured through RRC signaling or dynamically configured by the base station through the UL grant DCI. In this case as well, when the channel occupation time (COT) of the base station includes the UL grant DCI transmission time slot containing PUSCH resource allocation information and the PUSCH transmission time slot, PUSCH transmission can be performed in the corresponding UE without performing LBT operation.

[0225] In this regard, according to an embodiment of the present disclosure, the base station may configure an LBT scheme for performing LBT when sending PUCCH or PUSHC at the UE and indicate it to the UE. For example, the LBT scheme may be divided into multiple schemes based on whether an LBT operation is performed, whether a random backoff procedure is performed, and at least one of a random backoff time. In the present disclosure, the method for performing LBT is referred to as an "LBT scheme", but is not limited thereto. The LBT scheme for performing LBT may be variously referred to as an LBT category.

[0226] For example, the LBT scheme may include a first LBT scheme that does not perform LBT operations; a second LBT scheme that performs LBT operations but does not perform a random backoff procedure; a third LBT scheme in which LBT operations and random backoff procedures are performed, but the shutdown time interval is fixed; and a fourth LBT scheme in which LBT operations and random backoff procedures are performed, but the shutdown time interval is variable.

[0227] For example, the base station can directly instruct the UE whether to perform LBT operation for uplink transmission through physical layer (L1) control signaling. Specifically, LBT indication information for indicating whether to perform LBT operation on the UE's uplink transmission can be included in the DL allocation DCI format used to transmit PDSCH scheduling control information.

[0228] For example, the LBT indication information may be a 1-bit indication information bit. In this case, whether the LBT operation is performed on the corresponding UE may be defined based on the bit value (0, 1) of the LBT indication information when the UE corresponding to the downlink allocation DCI format transmits the PUCCH. In this case, the bit value of the LBT indication information may be used to distinguish between the first LBT scheme and the remaining LBT schemes in the above-mentioned LBT schemes.

[0229] As another example, the LBT indication information can be 2-bit indication information. In this case, when the UE corresponding to the DL allocation DCI format sends a PUCCH, whether the corresponding UE performs LBT operation can be defined according to the bit value (00, 01, 10, 11) of the LBT indication information. In this case, the bit value of the LBT indication information can mean identifying the first LBT scheme to the fourth LBT scheme in the above-mentioned LBT scheme.

[0230] In this case, the PUCCH transmission of the UE corresponding to the above-mentioned DL allocation DCI format can be a PUCCH transmission for transmitting HARQ feedback information of the UE based on the corresponding DL allocation DCI format and according to the PDSCH reception of the UE. The PUCCH transmission of the UE corresponding to the downlink allocation DCI format can be a PUCCH transmission for CQI / CSI reporting when the corresponding downlink allocation DCI format triggers CQI / CSI reporting.

[0231] The LBT indication information may be defined as being included in a UL grant DCI format for transmitting PUSCH scheduling control information.

[0232] For example, the LBT indication information may be a 1-bit indication information bit. In this case, whether LBT is performed at the corresponding UE may be defined based on the bit value (0, 1) of the LBT indication information when the UE corresponding to the uplink grant DCI format sends the PUCCH. In this case, the bit value of the LBT indication information may be used to distinguish between the first LBT scheme and the remaining LBT schemes in the above-mentioned LBT schemes.

[0233] As another example, the LBT indication information may be 2-bit indication information. In this case, when the UE corresponding to the UL grant DCI format sends a PUCCH, whether the corresponding UE performs an LBT operation may be defined based on the bit value (00, 01, 10, 11) of the LBT indication information. In this case, the bit value of the LBT indication information may mean identifying the first to fourth LBT schemes in the above-mentioned LBT schemes.

[0234] In this case, the PUCCH transmission of the UE corresponding to the above-mentioned UL grant DCI format may be PUCCH transmission for uplink data transmission or UCI transmission.

[0235] According to another embodiment, whether to perform the LBT scheme or the type of the LBT scheme on the uplink transmission of the UE may be determined according to a time gap value between a downlink transmission indicating the uplink transmission and a corresponding uplink transmission, such as Figure 12 shown.

[0236] For example, if the timing gap value is less than a threshold, it can be defined that the indicated PUCCH or PUSCH can be sent without performing an LBT operation at the corresponding UE. Alternatively, if the timing gap value is greater than the corresponding threshold, it can be defined that the corresponding PUCCH or PUSCH can be sent after the corresponding UE performs an LBT operation.

[0237] For example, the threshold value may be determined by the COT value in the corresponding NR-U, or the threshold value may be configured based on cell-specific RRC signaling, UE-specific RRC signaling of the base station according to the COT, or cell-specific RRC signaling or UE-specific RRC signaling of the base station regardless of the COT.

[0238] Furthermore, the threshold value may be defined as a single threshold value for each uplink transmission situation, or the threshold values ​​may be defined as threshold values ​​different from each other and then configured through specific RRC signaling or UE-specific RRC signaling.

[0239] According to the above process, it is possible to determine an LBT scheme to be performed in order to transmit an uplink signal in an unlicensed band and transmit the uplink signal in the unlicensed band according to the determined LBT scheme.

[0240] As described above, in NR, a bandwidth part (BWP) can be configured for each UE to transmit and receive uplink or downlink radio physical channels and physical signals for the UE, and one BWP is activated and used. In addition, unlike LTE, the system bandwidth constituting the NR cell can be configured as a broadband of more than 100 MHz according to the frequency range (FR) in which the corresponding NR cell is configured, and accordingly, the bandwidth of one BWP of the UE can be configured as a broadband of more than 100 MHz. In contrast, in the case where the DL or UL BWP of the UE in the NR-U cell configured through unlicensed spectrum is greater than 20 MHz, when LBT can be performed in units of the corresponding BWP for uplink or downlink transmission and reception, the competitiveness in terms of channel access probability may be severely reduced compared to other RATs (such as Wi-Fi) that perform LBT in units of 20 MHz.

[0241] To address this issue, a method can be considered to divide the DL or UL BWP configured for the UE into sub-bands with different bandwidths. LBT is performed in the corresponding sub-band units to transmit and receive uplink / downlink control channels and data channels. In other words, the BWP configured in the UE can be composed of N sub-bands.

[0242] For example, it can be defined that if the bandwidth of the DL BWP configured for a UE on the downlink is 80 MHz, the corresponding DL BWP can be divided into four sub-bands, each with a bandwidth of 20 MHz. Resources can be allocated and PDCCH or PDSCH can be transmitted and received based on the corresponding sub-band. Similar definitions can be made for the uplink. For example, it can be defined that if the bandwidth of a UL BWP is 60 MHz, the corresponding UL BWP can be divided into three sub-bands, each with a bandwidth of 20 MHz. Resources can be allocated and PUCCH or PUSCH can be transmitted and received based on the corresponding sub-band.

[0243] The present disclosure introduces a method for configuring a frequency band in units of LBT for the system bandwidth of a downlink or uplink carrier configured for any NR-U cell or the DL or UL BWP configured for a UE of the cell, and a method for transmitting downlink control information accordingly. Specifically, the present disclosure introduces a method for configuring UE group-common DCI transmitted via a corresponding PDCCH when the LBT execution result of the sub-band unit in the downlink transmission of the base station is transmitted via the UE group-common PDCCH.

[0244] In the present disclosure, the frequency bandwidth as a unit of LBT for transmission by a base station or UE in an NR-U cell is referred to as a sub-band, but the present disclosure is not limited to this name. For example, the frequency bandwidth in units of LBT may be referred to as other names, such as LBT bandwidth or channel access bandwidth. In addition, in the following disclosure, any value is "signaled by a base station", "configured by base station signaling" or "signaled from a base station" means that the corresponding value is configured by UE-specific or UE group common or cell-specific RRC signaling, MAC control element signaling (MAC CE signaling) or physical layer control signaling (L1 control signaling). The embodiments of the present disclosure described below may be applied alone or in any combination.

[0245] Embodiment 1. Method for configuring sub-bands

[0246] Example 1-1. UE-specific configuration

[0247] A resource block set (eg, sub-band) may be configured in units of a DL or UL BWP configured for a UE. Accordingly, for a DL or UL BWP configured for a UE, a sub-band may be implicitly configured according to configuration information of each BWP.

[0248] For example, the corresponding sub-band can be configured based on the frequency resource allocation information and SCS value configured with each BWP. That is, no separate information area is defined for configuring the sub-band, and the corresponding sub-band can be configured according to the existing RRC parameters required for any BWP configuration.

[0249] For example, reference Figure 13 , the subband configured according to the BWP can be configured from the lowest PRB of the corresponding BWP. In this case, the number of PRBs constituting a subband (i.e., the value N) can be determined as a function of the SCS value configured with the corresponding BWP. In addition, according to an embodiment, a guard band can be configured between each subband. In this case, the number of PRBs constituting the corresponding guard band (the value M) can also be determined as a function of the SCS value. However, in this case, the number of PRBs constituting the last subband may be less than the value N.

[0250] Alternatively, when configuring a sub-band in any BWP, such as Figure 14 As shown, the lowest sub-band corresponding to the BWP can be configured to be smaller than Figure 13 The size of the subband determined in the BWP (in other words, N PRBs) can be configured through base station signaling. In this case, the size of the first subband, that is, the number of PRBs (N0 value), can be configured through base station signaling. Alternatively, the offset value between the lowest PRB of the second subband and the lowest PRB of the BWP (e.g., the starting PRB, PRB#0) can be configured through base station signaling.

[0251] In addition, the size of the sub-band, the N value or the size of the guard band, the M value can also be configured through signaling of the base station.

[0252] Example 1-2. Cell-specific or carrier-specific configuration

[0253] The subband can be configured in units of the system bandwidth configured with the corresponding NR-U cell, or in units of the carrier bandwidth of each parameter set, regardless of the bandwidth part (BWP) configured for the UE. Specifically, the subband can be configured based on the common resource block (CRB) from point A.

[0254] refer to Figure 15 , the sub-band can be configured by the lowest CRB (e.g., CRB 0) configured from point A. In this case, the number of CRBs constituting each sub-band (i.e., R value) can be determined by the SCS of the corresponding CRB or can be configured through signaling from the base station. Similarly, a guard band can be configured between each sub-band, and the number of CRBs constituting the corresponding guard band (S value) can also be determined by the SCS value of the corresponding CRB or can be configured through signaling from the base station.

[0255] like Figure 16 As shown, the subband can be configured in units of subcarrier spacing specific (SCS specific) carrier bandwidth. That is, based on the carrier bandwidth configuration information of the subcarrier spacing (SCS), it can be defined that the subband is independently configured within the carrier bandwidth of each SCS.

[0256] In this case, the subbands of any SCS specific carrier bandwidth can be configured from the lowest CRB of the corresponding carrier bandwidth. In this case, the size of each subband (i.e., the number of CRBs as the P value) can be determined by the SCS as described above or can be configured through higher layer signaling. Similarly, a guard band can be configured between each subband, and the number of CRBs constituting the corresponding guard band (i.e., the Q value) can also be determined by the SCS value of the corresponding CRB, or can be configured through signaling from the base station. However, in this case, the number of CRBs constituting the last subband may be less than the P value.

[0257] like Figure 17 As shown, the lowest sub-band in any SCS specific carrier bandwidth can be configured to be smaller than Figure 16 In this case, the size of the first sub-band (i.e., the number of CRBs as the P0 value) may be configured through signaling from the base station. Alternatively, the offset value between the lowest CRB of the second sub-band and the lowest CRB of the corresponding SCS specific carrier bandwidth (i.e., the starting CRB) may be configured through signaling from the base station.

[0258] However, in the above example, the number of PRBs constituting each sub-band and guard band, that is, the N, M, R, S, P, Q values ​​may be different for each sub-band or guard band.

[0259] In addition, when PDSCH or PUSCH frequency resources are allocated to a UE across two adjacent sub-bands according to the sub-band configuration, that is, when a guard band is included between the adjacent sub-bands, transmission through the corresponding guard band can be defined to be performed only when all LBTs of the two adjacent sub-bands are successful.

[0260] Example 2. Method for configuring UE group common DCI

[0261] As described above, the base station may transmit the LBT result (eg, success / failure) of each sub-band for downlink transmission to the UE via the UE group common PDCCH. In this case, the LBT result may be transmitted via a bitmap for each sub-band.

[0262] However, since the BWP for a UE is configured as UE-specific, for UEs that receive LBT results for each sub-band from a base station via the same UE-group-common DCI, ambiguity may arise when interpreting the corresponding UE-group-common DCI when the frequency configurations of the DL BWPs activated for reception differ from one UE to another. In other words, generally speaking, since DL BWP configuration and activation are not exactly the same between UEs, it may be necessary to define a method for configuring UE-group-common DCI information to indicate the LBT results for each sub-band, as well as a method for the corresponding UE to interpret it.

[0263] As a method for this, the present disclosure introduces a method for defining a bitmap size, L value, and position of a bitmap constituting UE group common DCI, the bitmap corresponding to the subband of the DL BWP to which the UE group common DCI belongs configured in the L-bit bitmap of the UE.

[0264] As a method for this, the bitmap size (i.e., L value) can be determined by configuring the number of subbands (k value) constituting the corresponding DL BWP for each DL BWP of a certain UE according to the subband configuration method of embodiment 1. Specifically, the bitmap size L value of the UE group common PDCCH sent by the base station for the corresponding UE can be determined according to the number k value of subbands constituting the DL BWP activated for the certain UE. For example, there may be a corresponding L=k. In this case, the LBT result of each subband constituting the corresponding DL BWP has a 1:1 correspondence with the bits of all bitmaps constituting the corresponding UE group common PDCCH.

[0265] As another method, the bitmap size (i.e., L value) can be determined by the number of subbands constituting the system bandwidth from point A (i.e., m value). That is, the corresponding L=m can be determined according to the number of subbands constituting the entire system bandwidth of any NR-U cell (i.e., m value). In this case, the position of the bit corresponding to the subband constituting the DL BWP activated for any UE in the corresponding m-bit bitmap can also be implicitly determined according to the position of the corresponding DL BWP in the corresponding system bandwidth without the need for separate signaling.

[0266] Alternatively, the position information of the corresponding bit may be signaled by the base station. In this case, the parameters for performing the corresponding signaling may include offset information from the MSB (most significant bit) or LSB (least significant bit) constituting the bitmap and bit width information from the corresponding offset, or the corresponding bit width information may not be separately signaled and may be determined by the number of sub-bands constituting the corresponding DL BWP.

[0267] As another method, the corresponding L=n can be determined according to the number n of sub-bands constituting the SCS specific carrier bandwidth. In this case, the position of the bit corresponding to the sub-band constituting the DL BWP activated for any UE in the n-bit bitmap can be implicitly determined according to the position of the DL BWP in the corresponding SCS specific carrier bandwidth without separate signaling. Alternatively, the position information of the corresponding bit can be signaled by the base station, in which case the parameters used for the corresponding signaling can include offset information from the MSB or LSB constituting the bitmap and bit width information from the corresponding offset, or the corresponding bit width information is not separately signaled and can be determined by the number of sub-bands constituting the corresponding DL BWP.

[0268] As another method, the base station may signal the bitmap size (i.e., L value) configured by the corresponding UE group common DCI and the position information of the bits corresponding to the subbands constituting the DL BWP activated in any UE. That is, when configuring UE group common DCI transmission to transmit the LBT result for each subband, the base station may signal the bitmap size (i.e., L value) and the position-related information of the bits in the bitmap corresponding to the subbands constituting the DL BWP activated in each UE, i.e., the offset information of the MSB or LSB of the bitmap and the bit width information of the corresponding offset.

[0269] Furthermore, although the embodiments have been described based on downlink transmission of the base station, the same concepts of the embodiments can be applied to uplink transmission of the UE.

[0270] According to the above embodiments, a method and apparatus for configuring one or more sub-bands in an unlicensed frequency band and transmitting and receiving data based on the LBT results of the configured one or more sub-bands can be provided. This allows the UE to prevent the reduction in data transmission probability that may occur when performing LBT in a wideband area and to meet the data transmission QoS requirements using the unlicensed frequency band.

[0271] The following describes how to perform the combination with reference to the accompanying drawings. Figures 1 to 17 Configurations of UE and base station of all or some embodiments described.

[0272] Figure 18 is a diagram showing a configuration of a UE 1800 according to other embodiments.

[0273] Reference Figure 18 , the UE 1800 according to other embodiments includes a controller 1810 , a transmitter 1820 , and a receiver 1830 .

[0274] Controller 1810 controls the overall operation of UE 1800 according to the method for transmitting and receiving data in an unlicensed band required for performing the above disclosure. Transmitter 1820 transmits uplink control information and data or messages to a base station via a corresponding channel. Receiver 1830 receives downlink control information and data or messages from a base station via a corresponding channel.

[0275] Receiver 1830 may be configured to receive configuration information from a base station, the configuration information including parameters for configuring multiple resource block sets in an unlicensed band. Depending on the embodiment, subband configuration may be configured in units of a DL BWP or UL BWP configured for a UE. For a BWP configured for a UE, subbands may be implicitly configured based on the configuration information for each BWP. For example, the multiple subbands constituting each BWP may be configured based on the frequency resource allocation information and subcarrier spacing (SCS) value configured for each BWP.

[0276] That is, the configuration information including parameters for configuring multiple resource block groups in the unlicensed band may include guard band configuration information for configuring at least one guard band in the unlicensed band. The guard band configuration information may include SCS information for the bandwidth portion configured in the unlicensed band. In this case, the guard band configuration information may include SCS information for each of the at least one bandwidth portion configured for the UE in the unlicensed band. Alternatively, the guard band configuration information may also include bandwidth portion size information.

[0277] Each bandwidth part configured for a UE may be composed of multiple sub-bands and at least one guard band configured between each sub-band to distinguish each sub-band. Therefore, the number of guard bands included in a bandwidth part is one less than the number of sub-bands included in the same bandwidth.

[0278] According to an embodiment, the resource blocks (PRBs) constituting each of the at least one guard band may be determined based on the SCS information of the bandwidth portion including the guard band. Alternatively, the resource block set and the resource blocks constituting the guard band may be determined based on the SCS information of the bandwidth portion and the size information of the bandwidth portion.

[0279] If the number of resource blocks constituting a subband determined based on the SCS information and bandwidth part size information of the bandwidth part is N, each of the plurality of subbands may be composed of N resource blocks. Furthermore, if the number of resource blocks constituting a guard band determined based on the SCS information and bandwidth part size information of the bandwidth part is M, each of the at least one guard band may be composed of M resource blocks.

[0280] A sub-band consisting of N resource blocks and a guard band consisting of M resource blocks are alternately configured, and the last sub-band of the corresponding bandwidth part may consist of N resource blocks or less than N resource blocks.

[0281] According to an embodiment, the number of resource blocks constituting each sub-band of the bandwidth portion may be configured through base station signaling. That is, the configuration information may include the number of resource blocks constituting multiple sub-bands. In addition, the number of resource blocks constituting the guard band may also be configured through base station signaling.

[0282] Alternatively, the number of resource blocks constituting the guard band and the index of the starting resource block which is the lowest resource block among the resource blocks constituting each guard band are configured by signaling of the base station, and thus, the subband can be configured between the guard bands.

[0283] According to another embodiment, the subband configuration may be configured in units of the system bandwidth with which the corresponding NR-U cell is configured, or in units of the carrier bandwidth of each digital parameter set, regardless of the bandwidth portion configured for any UE. For example, the subband configuration may be configured based on a common resource block (CRB) from point A of the system bandwidth.

[0284] In this case, the guard band configuration information may include SCS information of the system bandwidth configured in the unlicensed band. Alternatively, the guard band configuration information may also include information about the system bandwidth size. Alternatively, according to another embodiment, the guard band configuration information may include subcarrier spacing information of a subcarrier spacing-specific (SCS-specific) carrier bandwidth. Alternatively, the guard band configuration information may also include information about the size of the corresponding bandwidth.

[0285] According to an embodiment, the common resource blocks constituting each of the at least one guard bands may be determined based on the SCS information of the system bandwidth. Alternatively, the common resource blocks constituting each of the at least one guard bands may be determined based on the SCS information of the system bandwidth and the size of the system bandwidth.

[0286] If the number of common resource blocks constituting a subband determined based on the SCS information of the system bandwidth is set to R, each of the multiple subbands may be composed of R common resource blocks. In addition, if the number of common resource blocks constituting a guard band determined based on the SCS information of the system bandwidth is S, each of the at least one guard band may be composed of S common resource blocks.

[0287] Alternatively, according to an embodiment, the number of resource blocks constituting each sub-band of the system bandwidth may be configured via base station signaling. That is, the configuration information may include the number of resource blocks constituting multiple sub-bands. Furthermore, the number of resource blocks constituting the guard band may also be configured via base station signaling.

[0288] Alternatively, the number of common resource blocks constituting the guard band and the index of the starting common resource block, which is the lowest common resource block among the common resource blocks constituting each guard band, can be configured via base station signaling. That is, the starting common resource block and the number of resource blocks for at least one guard band within the system bandwidth can be indicated via RRC signaling, etc. Therefore, multiple sub-bands can be configured between each guard band.

[0289] According to another embodiment, the resource blocks constituting each of the at least one guard bands may be determined based on the SCS information of the SCS specific carrier bandwidth. Alternatively, the resource blocks constituting each of the at least one guard bands may be determined based on the SCS information of the SCS specific carrier bandwidth and the size of the SCS specific carrier bandwidth.

[0290] If the number of resource blocks constituting a subband determined based on the SCS information of the SCS specific carrier bandwidth is set to P, each of the multiple subbands may be composed of P resource blocks. In addition, if the number of resource blocks constituting a guard band determined based on the SCS information of the SCS specific carrier bandwidth is Q, each of the at least one guard band may be composed of Q resource blocks.

[0291] Alternatively, the number of resource blocks constituting the guard band and the index of the starting resource block, which is the lowest resource block among the resource blocks constituting each guard band, can be configured through base station signaling. That is, the starting resource block within the SCS specific carrier bandwidth and the number of resource blocks in at least one guard band can be indicated through RRC signaling, etc. Therefore, multiple sub-bands can be configured between each guard band.

[0292] The controller 1810 may be configured to confirm a plurality of resource block sets based on the configuration information.

[0293] When multiple sub-bands are configured based on the SCS information of the bandwidth portion configured for the UE, the controller 1810 may obtain the SCS information of the bandwidth portion included in the configuration information. The controller 1810 may confirm the number of resource blocks constituting the sub-band or guard band based on the corresponding SCS information. Therefore, the controller 1810 may configure multiple sub-bands for the activated bandwidth portion based on the corresponding number.

[0294] This may also apply even when the number of resource blocks constituting a subband or a guard band is determined based on the SCS information of the system bandwidth or the SCS-specific carrier bandwidth.

[0295] When the number of resource blocks constituting a subband or a guard band and the index of a starting resource block are configured by signaling of the base station, the UE can confirm the resource blocks constituting each of the subband and the guard band included in the configuration information.

[0296] The receiver 1830 may transmit / receive data to / from the base station through at least one resource block set determined based on a result of performing listen-before-talk (LBT) on each of a plurality of resource block sets received from the base station.

[0297] As described above, when multiple subbands are configured for any of the bandwidth parts, system bandwidth, or SCS-specific carrier bandwidth, the base station can perform LBT on a per-subband basis. That is, in this disclosure, a subband can represent the LBT bandwidth corresponding to the unit for performing LBT on the frequency axis. Therefore, resource allocation for DL ​​BWPs and PDCCH or PDSCH transmission and reception can be performed on a per-subband basis.

[0298] The base station can perform LBT operations for each of the multiple sub-bands and configure a bitmap indicating the LBT execution result. That is, the base station can send the LBT result (e.g., success / failure) for each sub-band used for downlink transmission to the UE via the UE group-common PDCCH. The UE can receive downlink control information including the corresponding bitmap from the base station.

[0299] In this case, the size of the bitmap may be determined based on the number of sub-bands. For example, it is assumed that the bitmap constituting the UE group common DCI consists of L bits.

[0300] When multiple subbands are configured for a bandwidth portion, the L value can be determined by the number of subbands (k value) that constitute the corresponding BWP for each BWP configured for the UE. For example, the LBT result for each subband can be indicated in a 1:1 correspondence with the bits of the corresponding bitmap. That is, it can be determined as L = k.

[0301] When multiple subbands are configured for the system bandwidth, the L value can be determined by the number of subbands (m value) that constitute the system bandwidth starting from point A. For example, the LBT result for each subband can be indicated in a 1:1 correspondence with the bits of the corresponding bitmap. That is, it can be determined as L = m.

[0302] When multiple subbands are configured for an SCS specific carrier bandwidth, the value of L can be determined by the number n of subbands that constitute the SCS specific carrier bandwidth. For example, the LBT result for each subband can be indicated in a 1:1 correspondence with the bits in the corresponding bitmap. That is, L can be determined as n.

[0303] Alternatively, according to another embodiment, the bitmap size, L value, and position information of bits corresponding to multiple sub-bands configured for the UE configured through the corresponding UE group common DCI may all be signaled by the base station.

[0304] The receiver 1830 may receive scheduling information about at least one sub-band resource determined based on the LBT execution result from the base station, and may receive downlink data from the base station or transmit uplink data to the base station according to the corresponding scheduling information.

[0305] According to one embodiment, it is assumed that resources for transmitting and receiving data are allocated in a frequency band comprising one guard band from at least one guard band and two resource block sets with one guard band between them. That is, resource allocation for data transmission and reception can be performed for a band comprising two sub-bands and a guard band between them. In this case, transmitter 1820 and receiver 1830 can only transmit and receive data with the base station in the frequency band if the LBT operation for both resource block sets is successful. In other words, only when the LBT result for the two sub-bands with the guard band between them is successful can link data transmission and reception be performed via the corresponding guard band.

[0306] According to the above embodiments, a method and apparatus for configuring one or more sub-bands in an unlicensed frequency band and transmitting and receiving data based on LBT results for the configured one or more sub-bands can be provided. This allows the UE to prevent a decrease in the probability of data transmission that may occur due to LBT operations in a wideband region and to meet the QoS requirements for data transmission using the unlicensed frequency band.

[0307] Figure 19 is a block diagram illustrating a base station 1900 according to an embodiment.

[0308] Reference Figure 19 , the base station 1900 includes a controller 1910, a transmitter 1920 and a receiver 1930.

[0309] The controller 1910 controls the overall operation of the base station 1900 according to a method of receiving uplink control information in an unlicensed band required for performing the above disclosure. The transmitter 1920 and the receiver 1930 are used to transmit or receive signals, messages, or data required for performing the above disclosure with the UE.

[0310] The transmitter 1920 may be configured to transmit configuration information including parameters for configuring a plurality of resource block sets in an unlicensed band to the UE.

[0311] According to the embodiment, the configuration of resource block sets (i.e., subbands) can be configured in units of the DL BWP or UL BWP configured for the UE. For the BWP configured for the UE, the subbands can be implicitly configured based on the configuration information of each BWP. For example, the multiple subbands constituting each BWP can be configured based on the frequency resource allocation information and subcarrier spacing (SCS) value configured for each BWP.

[0312] That is, the configuration information including parameters for configuring multiple resource block sets in the unlicensed band may include guard band configuration information for configuring at least one guard band in the unlicensed band. The guard band configuration information may include SCS information for the bandwidth portion configured in the unlicensed band. In this case, the guard band configuration information may include SCS information for each of the at least one bandwidth portion configured for the UE in the unlicensed band. Alternatively, the guard band configuration information may also include bandwidth portion size information.

[0313] Each bandwidth part configured for a UE may be composed of multiple sub-bands and at least one guard band configured between each sub-band to distinguish each sub-band. Therefore, the number of guard bands included in a bandwidth part is one less than the number of sub-bands included in the same bandwidth.

[0314] According to an embodiment, the resource blocks (PRBs) constituting each of the at least one guard band may be determined based on the SCS information of the bandwidth portion including the guard band. Alternatively, the resource block set and the resource blocks constituting the guard band may be determined based on the SCS information of the bandwidth portion and the size information of the bandwidth portion.

[0315] If the number of resource blocks constituting a subband determined based on the SCS information and bandwidth part size information of the bandwidth part is N, each of the plurality of subbands may be composed of N resource blocks. Furthermore, if the number of resource blocks constituting a guard band determined based on the SCS information and bandwidth part size information of the bandwidth part is M, each of the at least one guard band may be composed of M resource blocks.

[0316] According to an embodiment, the number of resource blocks constituting each sub-band of the bandwidth portion may be configured through base station signaling. That is, the configuration information may include the number of resource blocks constituting multiple sub-bands. In addition, the number of resource blocks constituting the guard band may also be configured through base station signaling.

[0317] Alternatively, the number of resource blocks constituting the guard band and the index of the starting resource block, which is the lowest resource block among the resource blocks constituting each guard band, are configured by signaling from the base station. Therefore, the sub-band can be configured between the guard bands.

[0318] According to another embodiment, the subband configuration may be configured in units of the system bandwidth with which the corresponding NR-U cell is configured, or in units of the carrier bandwidth of each digital parameter set, regardless of the bandwidth portion configured for any UE. For example, the subband configuration may be configured based on a common resource block (CRB) from point A of the system bandwidth.

[0319] In this case, the guard band configuration information may include SCS information of the system bandwidth configured in the unlicensed band. Alternatively, the guard band configuration information may also include information about the system bandwidth size. Alternatively, according to another example, the guard band configuration information may include subcarrier spacing information of a subcarrier spacing-specific (SCS-specific) carrier bandwidth. Alternatively, the guard band configuration information may also include information about the size of the corresponding bandwidth.

[0320] According to an embodiment, the common resource blocks constituting each of the at least one guard bands may be determined based on the SCS information of the system bandwidth. Alternatively, the common resource blocks constituting each of the at least one guard bands may be determined based on the SCS information of the system bandwidth and the size of the system bandwidth.

[0321] If the number of common resource blocks constituting a subband determined based on the SCS information of the system bandwidth is set to R, each of the multiple subbands may be composed of R common resource blocks. In addition, if the number of common resource blocks constituting a guard band determined based on the SCS information of the system bandwidth is S, each of the at least one guard band may be composed of S common resource blocks.

[0322] Alternatively, according to an embodiment, the number of resource blocks constituting each sub-band of the system bandwidth may be configured via base station signaling. That is, the configuration information may include the number of resource blocks constituting multiple sub-bands. Furthermore, the number of resource blocks constituting the guard band may also be configured via base station signaling.

[0323] Alternatively, the number of common resource blocks constituting the guard band and the index of the starting common resource block, which is the lowest common resource block among the common resource blocks constituting each guard band, can be configured via base station signaling. That is, the starting common resource block and the number of resource blocks for at least one guard band within the system bandwidth can be indicated via RRC signaling, etc. Therefore, multiple sub-bands can be configured between each guard band.

[0324] According to another embodiment, the resource blocks constituting each of the at least one guard bands may be determined based on the SCS information of the SCS specific carrier bandwidth. Alternatively, the resource blocks constituting each of the at least one guard bands may be determined based on the SCS information of the SCS specific carrier bandwidth and the size of the SCS specific carrier bandwidth.

[0325] If the number of resource blocks constituting a subband determined based on the SCS information of the SCS specific carrier bandwidth is set to P, each of the multiple subbands may be composed of P resource blocks. In addition, if the number of resource blocks constituting a guard band determined based on the SCS information of the SCS specific carrier bandwidth is Q, each of the at least one guard band may be composed of Q resource blocks.

[0326] Alternatively, according to an embodiment, the number of resource blocks for each of the multiple sub-bands comprising the SCS specific carrier bandwidth may be configured via base station signaling. That is, the configuration information may include the number of resource blocks comprising the multiple sub-bands. Furthermore, the number of resource blocks comprising the guard band may also be configured via base station signaling.

[0327] Alternatively, the number of resource blocks constituting the guard band and the index of the starting resource block, which is the lowest resource block among the resource blocks constituting each guard band, can be configured through base station signaling. That is, the starting resource block within the SCS specific carrier bandwidth and the number of resource blocks in at least one guard band can be indicated through RRC signaling, etc. Therefore, multiple sub-bands can be configured between each guard band.

[0328] The transmitter 1920 may transmit a result of performing listen-before-talk (LBT) on each of a plurality of resource block sets to the UE.

[0329] As described above, when multiple sub-bands are configured for any of the bandwidth part, system bandwidth, or SCS specific carrier bandwidth, the controller 1910 may perform LBT operations in units of the corresponding sub-bands. That is, in the present disclosure, a sub-band may represent an LBT bandwidth corresponding to a unit for performing LBT on the frequency axis.

[0330] As described above, in order to transmit a radio signal from any node in an unlicensed frequency band, the LBT process for confirming whether the radio channel is occupied by another node may be preferentially performed. Therefore, in order to transmit PDSCH for a UE in an NR-U cell in an unlicensed frequency band configured by a certain NR base station, the controller 1910 needs to perform LBT on the frequency band configured for the NR-U cell. As a result of performing LBT, when the wireless channel in the unlicensed frequency band is empty, the transmitter 1920 can send PDCCH and PDSCH to the UE accordingly.

[0331] For example, the controller 1910 may perform LBT for each of the multiple sub-bands and configure a bitmap indicating the LBT execution result. That is, the base station may transmit the LBT result (e.g., success / failure) for each sub-band for downlink transmission to the UE via the UE group common PDCCH. The transmitter 1920 may transmit downlink control information including the corresponding bitmap to the UE.

[0332] In this case, the size of the bitmap may be determined based on the number of the plurality of sub-bands. For example, it is assumed that the bitmap constituting the UE group common DCI consists of L bits.

[0333] When multiple sub-bands are configured for a bandwidth portion, the L value can be determined by the number of sub-bands (k value) that constitute the corresponding BWP for each BWP set for the UE. For example, the LBT result for each sub-band can be indicated in a 1:1 correspondence with the bits of the corresponding bitmap. That is, it can be determined as L = k.

[0334] When multiple subbands are configured for the system bandwidth, the L value can be determined by the number of subbands (m value) that constitute the system bandwidth starting from point A. For example, the LBT result for each subband can be indicated in a 1:1 correspondence with the bits of the corresponding bitmap. That is, it can be determined as L = m.

[0335] When multiple subbands are configured for an SCS specific carrier bandwidth, the value of L can be determined by the number n of subbands that constitute the SCS specific carrier bandwidth. For example, the LBT result for each subband can be indicated in a 1:1 correspondence with the bits in the corresponding bitmap. That is, L can be determined as n.

[0336] Alternatively, according to another embodiment, the bitmap size and L value configured through the corresponding UE group common DCI and the position information of the bits corresponding to the multiple sub-bands configured for the UE may all be signaled by the base station.

[0337] Transmitter 1920 may transmit data to the UE using at least one resource block set determined based on the result of performing LBT. Transmitter 1920 may transmit scheduling information for at least one sub-band resource determined based on the result of performing LBT to the UE. That is, transmitter 1920 may transmit downlink data using at least one sub-band in which the LBT operation was successful. Transmitter 1920 may transmit downlink data to the UE based on the corresponding scheduling information.

[0338] The receiver 1930 may receive uplink data from the UE using at least one resource block set determined based on the result of performing LBT. The receiver 1930 may receive uplink data from the UE based on scheduling information of at least one sub-band resource determined based on the result of performing LBT.

[0339] According to the above embodiments, a method and apparatus for configuring one or more sub-bands in an unlicensed frequency band and transmitting and receiving data based on the LBT results of the configured one or more sub-bands can be provided. This allows the UE to prevent the reduction in data transmission probability that may occur when performing LBT in a wideband area and to meet the data transmission QoS requirements using the unlicensed frequency band.

[0340] The above-described embodiments may be supported by standard documents disclosed in at least one of the radio access systems of IEEE 802, 3GPP, and 3GPP2. Specifically, steps, configurations, and components not described in this embodiment may be supported by these standard documents to clarify the technical concepts of the present disclosure. Furthermore, all terms disclosed herein may be described in these standard documents.

[0341] The above embodiments may be implemented in any of a variety of ways. For example, the embodiments may be implemented as hardware, firmware, software, or a combination thereof.

[0342] In the case of hardware implementation, the method according to the embodiment of the present invention can be implemented as at least one of an application-specific integrated circuit (ASIC), a parameter set signal processor (DSP), a parameter set signal processing device (DSPD), a programmable logic device (PLD), a field programmable gate array (FPGA), a processor, a controller, a microcontroller or a microprocessor.

[0343] When implemented by firmware or software, the method according to this embodiment can be implemented in the form of a device, process, or function for performing the above-mentioned functions or operations. The software code can be stored in a storage unit and can be driven by a processor. The storage unit can be located inside or outside the processor and can exchange data with the processor in any of various well-known ways.

[0344] In addition, the terms "system", "processor", "controller", "component", "module", "interface", "model", "unit", etc. can generally refer to physical hardware, a combination of hardware and software, software or running software related to a computer. For example, the above components can be, but are not limited to, a processor, a processor, a controller, a control processor, an entity, an execution thread, a program and / or a computer-driven process. For example, an application running in a controller or processor and the controller or processor can be a component. One or more components can be provided in a process and / or execution thread, and these components can be provided in a single device (e.g., a system, a computing device, etc.) or can be distributed across two or more devices.

[0345] The above embodiments of the present disclosure are described for illustrative purposes only, and those skilled in the art will understand that various modifications and changes may be made thereto without departing from the scope and spirit of the present disclosure. In addition, the embodiments of the present disclosure are not intended to limit, but rather to illustrate the technical ideas of the present disclosure. Therefore, the scope of the technical ideas of the present disclosure is not limited by these embodiments. The scope of the present disclosure should be interpreted based on the appended claims, so that all technical ideas included in the scope equivalent to the claims belong to the present disclosure.

Claims

1. A method for transmitting and receiving data by a user equipment in an unlicensed frequency band, the method comprising: receiving configuration information from a base station, the configuration information including parameters for configuring a plurality of resource block sets in the unlicensed frequency band; confirming the plurality of resource block sets in the unlicensed frequency band according to the configuration information; as well as transmitting and receiving data with the base station through at least one resource block set, wherein the at least one resource block set is determined based on a result of performing a listen-before-talk (LBT) on each of the plurality of resource block sets received from the base station, Each of the plurality of resource block sets in the unlicensed frequency band is determined based on subcarrier spacing information of a bandwidth portion configured for the user equipment and size information of the bandwidth portion, The configuration information includes guard band configuration information for configuring at least one guard band in the unlicensed frequency band, and the at least one guard band is configured between the multiple resource block sets so that each of the multiple resource block sets is distinguished in the unlicensed frequency band.

2. The method according to claim 1, wherein The guard band configuration information includes subcarrier spacing information of the system bandwidth configured in the unlicensed frequency band or subcarrier spacing information of the specific carrier bandwidth. The number of resource blocks constituting the at least one guard band is determined according to the subcarrier spacing information of the system bandwidth or the subcarrier spacing information of the subcarrier-spacing-specific carrier bandwidth.

3. The method according to claim 1, wherein The guard band configuration information includes a starting common resource block (CRB) of the at least one guard band and the number of resource blocks constituting the at least one guard band.

4. The method according to claim 1, wherein In the step of sending or receiving the data, when the resources for sending and receiving data are allocated in a frequency band including one of the at least one guard band and two resource block sets, the data is sent or received in the frequency band only if LBT for both resource block sets is successful, and the two resource block sets have the one guard band among the multiple resource block sets between them.

5. A method for a base station to transmit and receive data in an unlicensed frequency band, the method comprising: Sending configuration information to a user equipment, the configuration information including parameters for configuring a plurality of resource block sets in the unlicensed frequency band; transmitting a result of performing listen-before-talk (LBT) on each of the plurality of resource block sets; as well as transmitting the data to or receiving the data from the user equipment through at least one resource block set, wherein the at least one resource block set is determined based on a result of performing the LBT, Each of the plurality of resource block sets is composed of a plurality of resource blocks whose number is determined based on the configuration information, Each of the plurality of resource block sets in the unlicensed frequency band is determined based on subcarrier spacing information of a bandwidth portion configured for the user equipment and size information of the bandwidth portion, The configuration information includes guard band configuration information for configuring at least one guard band in the unlicensed frequency band, and the at least one guard band is configured between the multiple resource block sets so that each of the multiple resource block sets is distinguished in the unlicensed frequency band.

6. The method according to claim 5, wherein: The guard band configuration information includes subcarrier spacing information of the system bandwidth configured in the unlicensed frequency band or subcarrier spacing information of the specific carrier bandwidth. The number of resource blocks constituting the at least one guard band is determined according to subcarrier spacing information of the system bandwidth or subcarrier spacing information of the subcarrier spacing specific carrier bandwidth.

7. The method according to claim 5, wherein: The guard band configuration information includes a starting common resource block (CRB) of the at least one guard band and the number of resource blocks constituting the at least one guard band.

8. The method according to claim 5, wherein In the step of sending or receiving the data, when the resources for sending and receiving data are allocated in a frequency band including one of the at least one guard band and two resource block sets, the data is sent or received in the frequency band only if LBT for both resource block sets is successful, and the two resource block sets have the one guard band among the multiple resource block sets between them.

9. A user equipment for transmitting and receiving data in an unlicensed frequency band, the user equipment comprising: a transmitter configured to transmit data to a base station; a receiver configured to receive configuration information from the base station, the configuration information comprising parameters for configuring a plurality of resource block sets in the unlicensed band; as well as a controller configured to confirm the plurality of resource block sets based on the configuration information, wherein the receiver receives data from the base station through at least one resource block set, the at least one resource block set being determined based on a result of performing listen-before-talk (LBT) on each of the plurality of resource block sets received from the base station, and The transmitter sends data to the base station through the at least one resource block set, Each of the plurality of resource block sets in the unlicensed frequency band is determined based on subcarrier spacing information of a bandwidth portion configured for the user equipment and size information of the bandwidth portion, The configuration information includes guard band configuration information for configuring at least one guard band in the unlicensed frequency band, and the at least one guard band is configured between the multiple resource block sets so that each of the multiple resource block sets is distinguished in the unlicensed frequency band.

10. The user equipment according to claim 9, wherein: The guard band configuration information includes subcarrier spacing information of the system bandwidth configured in the unlicensed frequency band or subcarrier spacing information of the specific carrier bandwidth. The number of resource blocks constituting the at least one guard band is determined according to the subcarrier spacing information of the system bandwidth or the subcarrier spacing information of the subcarrier-spacing-specific carrier bandwidth.

11. The user equipment according to claim 9, wherein: The guard band configuration information includes a starting common resource block (CRB) of the at least one guard band and the number of resource blocks constituting the at least one guard band.

12. The user equipment according to claim 9, wherein: When resources for transmitting and receiving data are allocated in a frequency band including one of the at least one guard band and two resource block sets, the receiver receives the data from the base station in the frequency band and the transmitter sends the data to the base station in the frequency band only if LBT for the two resource block sets is successful, and the two resource block sets have the one guard band from the multiple resource block sets between them.

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