Resource allocation method for transmitting in an unlicensed bandwidth and apparatus using the same

Abstract

The present invention provides a method and apparatus for allocating resources for uplink transmission over an unlicensed band in a wireless communication system, particularly a cellular wireless communication system, for transmitting scheduling information at a base station and receiving and transmitting it at a terminal, as well as the system itself. [Solution] The present invention provides a method and apparatus for efficiently transmitting signals in a wireless communication system, particularly a cellular wireless communication system. Another object of the present invention is to provide a method for efficiently sensing a channel in a specific frequency band (e.g., an unlicensed band) and transmitting a signal / channel, a method for receiving said signal / channel, and an apparatus for said.

Description

Technical Field

[0001] The present invention relates to a method for allocating uplink resources when using an NR-based frame structure and system in an unlicensed band, and to the transmission of resource allocation information in a base station, the reception and transmission methods in a terminal, an apparatus, and a system.

Background Art

[0002] After the commercialization of the 4G (4th generation) communication system, efforts have been made to develop a new 5G (5th generation) communication system to meet the increasing demand for wireless data traffic. The 5G communication system is referred to as a communication system beyond the 4G network, a system post LTE, or an NR (new radio) system. To achieve a high data transmission rate, the 5G communication system includes systems operating using a millimeter wave (mmWave) band of above 6 GHz, and also includes communication systems operating using a frequency band of below 6 GHz from the aspect of ensuring coverage, and the implementation in a base station and a terminal is considered.

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

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

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

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

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

[0008] However, mobile communication systems have gradually expanded their service scope to include not only voice but also data services, and have now developed to the point where they can provide high-speed data services. However, due to resource shortages and user demand for high-speed services, there is a need for more advanced mobile communication systems in use today.

[0009] Recently, with the proliferation of smart devices and the resulting explosion in mobile traffic, traditional licensed frequency spectrums, or licensed frequency bands alone, are struggling to cope with the increasing data usage required to provide cellular communication services.

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

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

[0012] In order to use LTE and NR technologies in unlicensed bands, research should be conducted in advance on coexistence strategies with conventional unlicensed band equipment and strategies for efficiently sharing radio channels with other radio channels. In other words, a robust coexistence mechanism (RCM) needs to be developed so that equipment using LTE and NR technologies in unlicensed bands does not affect conventional unlicensed band equipment. [Overview of the Initiative] [Problems that the invention aims to solve]

[0013] The object of the present invention is to provide an uplink channel access method, a transmission and reception method and apparatus at a terminal, and a system for wireless communication systems, particularly cellular wireless communication systems, when performing wideband operation over an unlicensed band. Another object of the present invention is to provide a method and apparatus for efficiently transmitting signals in a wireless communication system, particularly a cellular wireless communication system. Furthermore, another object of the present invention is to provide a method for efficiently sensing a channel in a specific frequency band (e.g., an unlicensed band) and transmitting a signal / channel, as well as a method and apparatus for receiving said signal / channel.

[0014] The technical problems that this invention aims to solve are not limited to those described above, and other technical problems not mentioned will be clearly understood by those with ordinary skill in the art to which this invention belongs from the following description. [Means for solving the problem]

[0015] A terminal of a wireless communication system according to an embodiment of the present invention includes a communication module and a processor that controls the communication module. The processor receives Downlink Control Information (DCI) from a base station for the allocation of at least one subband and a plurality of resource blocks for transmitting PUSCH (Physical Uplink Shared Channel), and transmits the PUSCH to the base station using the plurality of resource blocks received with the DCI. The DCI includes first resource allocation information related to the location of the at least one subband and second resource allocation information related to the location of the plurality of resource blocks. The at least one subband is included in an activated bandwidth part (BWP) based on the first resource allocation information, and the plurality of resource blocks are included in an interlace structure that is allocated consecutively at regular intervals to the activated BWP based on the second resource allocation information.

[0016] Furthermore, in the present invention, at least one subband is allocated consecutively within the activated BWP based on the first resource allocation information.

[0017] Furthermore, in the present invention, the first resource allocation information related to the position of the at least one subband is included in the DCI in the RIV (Resource Indication Value) format.

[0018] Furthermore, in the present invention, the second resource allocation information related to the positions of the plurality of resource blocks is included in the DCI in a bitmap format or RIV (Resource Indication Value) format based on the subcarrier spacing.

[0019] Furthermore, in the present invention, when the subcarrier interval is 30 kHz, the second resource allocation information related to the positions of the plurality of resource blocks is included in the DCI in the bitmap format, and the positions of the plurality of resource blocks are indicated by the bit values ​​included in the second resource allocation information based on the bitmap format.

[0020] Furthermore, in the present invention, when the subcarrier interval is 15 kHz, the second resource allocation information related to the positions of the plurality of resource blocks is included in the DCI in the RIV method, and the second resource allocation information includes the start index of the plurality of resource blocks and the number of the plurality of resource blocks based on the RIV method.

[0021] Furthermore, in the present invention, the first resource allocation information includes the starting position and number of at least one subband.

[0022] Furthermore, in the present invention, both the first resource allocation information and the second resource allocation information are encoded and included in the DCI.

[0023] Furthermore, in the present invention, the instruction information, in which both the first resource allocation information and the second resource allocation information are encoded, is calculated sequentially in ascending order, prioritizing either the number of at least one subband or the start index of the plurality of resource blocks.

[0024] Furthermore, in the present invention, the plurality of resource blocks are included in the interlaced structure across at least one subband where LBT (Listen before talk) operation for channel access in the unlicensed band is performed.

[0025] The present invention also provides a method comprising the steps of: receiving Downlink Control Information (DCI) from a base station for the allocation of at least one subband and a plurality of resource blocks for transmitting PUSCH (Physical Uplink Shared Channel); and transmitting the PUSCH to the base station using the plurality of resource blocks received using the DCI, wherein the DCI includes first resource allocation information related to the location of the at least one subband and second resource allocation information related to the locations of the plurality of resource blocks, the at least one subband is included in an activated bandwidth part (BWP) based on the first resource allocation information, and the plurality of resource blocks are included in an interlace structure that is allocated consecutively at regular intervals in the activated BWP based on the second resource allocation information.

[0026] Furthermore, the present invention provides a base station comprising a communication module and a processor for controlling the communication module, wherein the processor transmits Downlink Control Information (DCI) to a terminal for the allocation of at least one subband and a plurality of resource blocks for transmitting PUSCH (Physical Uplink Shared Channel), and receives the PUSCH transmitted from the terminal using the plurality of resource blocks transmitted using the DCI, wherein the DCI includes first resource allocation information related to the location of the at least one subband and second resource allocation information related to the location of the plurality of resource blocks, the at least one subband is included in an activated bandwidth part (BWP) based on the first resource allocation information, and the plurality of resource blocks are included in an interlace structure that is allocated consecutively at regular intervals in the activated BWP based on the second resource allocation information. [Effects of the Invention]

[0027] According to embodiments of the present invention, a receiving and transmitting method and apparatus are provided for allocating resources for uplink transmission in a wireless communication system, particularly a cellular wireless communication system. Furthermore, a method and apparatus for efficiently transmitting signals by channel access in a specific frequency band (e.g., an unlicensed band) are also provided.

[0028] The effects obtained from the present invention are not limited to those mentioned above, and other effects not mentioned will be clearly understood by those with ordinary skill in the art to which the present invention pertains from the following description. [Brief explanation of the drawing]

[0029] [Figure 1] This figure shows an example of a wireless frame structure used in wireless communication systems. [Figure 2] This figure shows an example of a downlink (DL) / uplink (UL) slot structure in a wireless communication system. [Figure 3] This diagram illustrates the physical channels used in 3GPP systems and common signal transmission methods utilizing those physical channels. [Figure 4] This figure shows the SS / PBCH block for initial cell access in a 3GPP NR system. [Figure 5] This diagram shows the procedure for transmitting control information and control channels in a 3GPP NR system. [Figure 6] This diagram shows the CORESET (control resource set) through which the PDCCH (physical downlink control channel) is transmitted in a 3GPP NR system. [Figure 7] This diagram shows how to configure the PDCCH search space in a 3GPP NR system. [Figure 8] This is a conceptual diagram explaining career aggregation. [Figure 9] This is a diagram illustrating single-carrier and multiple-carrier communication. [Figure 10] This figure shows an example where the cross-carrier scheduling technique is applied. [Figure 11] This figure shows the configuration of a code block group (CBG) and its time-frequency resource mapping according to an embodiment of the present invention. [Figure 12] This diagram shows the process by which a base station performs TB-based transmission or CBG-based transmission according to an embodiment of the present invention, and a terminal transmits a HARQ-ACK in response thereto. [Figure 13] This diagram shows the NR-U (NR-Unlicensed) service environment. [Figure 14] This figure shows one example of a terminal and base station deployment scenario in an NR-U service environment. [Figure 15] This diagram shows a conventional communication method that operates on unlicensed bandwidth (e.g., wireless LAN). [Figure 16] This figure shows a channel access process based on Category 4 LBT according to one embodiment of the present invention. [Figure 17] This figure shows one example of how to adjust the competition window size (CWS) based on HARQ-ACK feedback. [Figure 18] This is a block diagram showing the configuration of a terminal and a base station according to one embodiment of the present invention. [Figure 19] This flowchart shows one embodiment of the present invention and an example of a method for transmitting uplink data in an unlicensed bandwidth. [Figure 20] This figure shows an example of a resource structure for transmission using PUSCH (Physical Uplink Shared Channel), which is one embodiment of the present invention. [Figure 21] This figure shows an example of an interlace structure for allocating uplink resources in LTE-LAA. [Figure 22] This figure shows an example of a candidate LBT subband for uplink push transmission and an interlacing structure for it on an activated Bandwidth Part (BWP) having multiple LBT (Listen Before Talk) subbands among one or more bandwidth parts (BWPs). [Figure 23] This flowchart illustrates yet another embodiment of the present invention, illustrating an example of a method for a terminal to be allocated unlicensed bandwidth resources from a base station to transmit uplink data. [Figure 24] This flowchart illustrates yet another embodiment of the present invention and an example of a method by which a base station allocates unlicensed bandwidth resources to a terminal to receive uplink data. [Modes for carrying out the invention]

[0030] The terminology used herein has been selected to be as widely used and general as possible, taking into account the function of the present invention; however, this may vary depending on the intentions, conventions, or emergence of new technologies of the articulate. In some cases, the applicant has arbitrarily selected certain terms, in which case their meaning will be described in the relevant section of the invention description. Therefore, it should be made clear that the terminology used herein should not be merely names of terms, but should be analyzed based on the substantive meaning of the terms and the overall content of this specification.

[0031] Throughout the specification, when one configuration is said to be “connected” to another, this includes not only cases where they are “directly connected,” but also cases where they are “electrically connected” through other intermediate components. Furthermore, when a configuration is said to “include” a particular component, this means, unless otherwise stated, that it includes other components rather than excluding them. In addition, the limitations of “greater than” or “less than” a particular critical point may be appropriately replaced by “greater than” or “less than” depending on the embodiment.

[0032] The following technologies are used in a variety of wireless connectivity systems, including CDMA (code division multiple access), FDMA (frequency division multiple access), TDMA (time division multiple access), OFDMA (orthogonal frequency division multiple access), and SC-FDMA (single carrier frequency division multiple access). CDMA is implemented using radio technology such as UTRA (Universal Terrestrial Radio Access) and CDMA2000. TDMA is implemented using radio technology such as GSM (Global System for Mobile communications) / GPRS (General Packet Radio Service) / EDGE (Enhanced Data Rates for GSM Evolution). OFDMA is implemented using radio technology such as IEEE802.11 (Wi-Fi), IEEE802.16 (WiMAX), IEEE802-20, and E-UTRA (Evolved UTRA). UTRA is part of UMTS (Universal Mobile Telecommunication System). 3GPP LTE (Long term evolution) is part of E-UMTS (Evolved UMTS) which uses E-UTRA, and LTE-A (Advanced) is an advanced version of 3GPP LTE. 3GPP NR is a system designed separately from LTE / LTE-A, and is intended to support eMBB (enhanced Mobile Broadband), URLLC (Ultra-Reliable and Low Latency Communication), and mMTC (massive Machine Type Communication) services, which are requirements of IMT-2020. While this explanation will focus on 3GPP NR for clarity, the technical concept of this invention is not limited to this.

[0033] Unless otherwise specified in this specification, the base station can include a gNB (next generation node B) defined in 3GPP NR. Also, unless otherwise specified, the terminal can include a UE (user equipment). Also, unless otherwise specified, the terminal can include a UE (user equipment). Hereinafter, for the sake of understanding the description, each content will be described separately as a separate embodiment, but each embodiment can be used in combination. In the present disclosure, the configuration of the terminal can represent the configuration by the base station. Specifically, the base station can transmit a channel or a signal to the terminal and set the value of the parameter used in the operation of the terminal or the radio communication system.

[0034] FIG. 1 is a diagram showing an example of a radio frame structure used in a radio communication system.

[0035] Referring to FIG. 1, the radio frame (or radio frame) used in the 3GPP NR system is 10 ms (Δf max N f / 100)*T c ) in length. Also, the radio frame consists of 10 equally sized subframes (subfame, SF). Here, Δf max = 480*10 3 Hz, N f = 4096, T c = 1 / (Δf ref *N f,ref ), Δf ref = 15*10 3 Hz, N f,ref = 2048. Each of the 10 subframes in one frame is given a number from 0 to 9. Each subframe has a length of 1 ms and consists of one or more slots depending on the subcarrier spacing. More specifically, the subcarrier spacing that can be used in the 3GPP NR system is 15*2 μThe frequency is kHz. μ is the subcarrier spacing configuration, and μ has values ​​from 0 to 4. That is, 15kHz, 30kHz, 60kHz, 120kHz, or 240kHz are used as subcarrier spacings. A subframe with a length of 1ms is 2 μ It consists of 2 slots. In this case, the length of each slot is 2 -μ It is ms. The 2μ slots within one subframe are each 0 to 2 μ Numbers are assigned from -1. Also, each slot within a single wireless frame is numbered from 0 to 10*2. μ A number up to -1 is assigned. Time resources are distinguished by at least one of the following: radio frame number (also called radio frame index), subframe number (also called subframe index), or slot number (also called slot index).

[0036] Figure 2 shows an example of a downlink (DL) / uplink (UL) slot structure in a wireless communication system. In particular, Figure 2 shows the resource grid structure of a 3GPP NR system.

[0037] There is one resource grid per antenna port. Referring to Figure 2, a slot contains multiple OFDM (orthogonal frequency division multiplexing) symbols in the time domain and multiple resource blocks (RBs) in the frequency domain. An OFDM symbol can also represent a single symbol interval. Unless otherwise specified, an OFDM symbol can simply be called a symbol. One RB contains 12 consecutive subcarriers in the frequency domain. Referring to Figure 2, the signal transmitted in each slot is N size,μ grid,x *N RB sc individual subcarriers and N slot symbThis can be described as a resource grid composed of n OFDM symbols. Here, for a downlink resource grid, x=DL, and for an uplink resource grid, x=UL. size,μ grid,x This represents the number of resource blocks (RB) due to the subcarrier spacing component μ (where x is DL or UL), N slot symb This represents the number of OFDM symbols in the slot. RB sc N is the number of subcarriers that make up one RB. RB sc = 12. OFDM symbols can be called CP-OFDM (cyclic prefix OFDM) symbols or DFT-S-OFDM (discrete Fourier transform spread OFDM) symbols depending on the multiplexing scheme.

[0038] The number of OFDM symbols in a single slot can vary depending on the length of the cyclic prefix (CP). For example, a normal CP may contain 14 OFDM symbols in a single slot, while an extended CP may contain 12 OFDM symbols in a single slot. In specific embodiments, extended CPs are used only at a subcarrier interval of 60 kHz. For the sake of explanation, Figure 2 illustrates a case where a single slot consists of 14 OFDM symbols, but the embodiments of the present invention can be applied in the same manner to slots with other numbers of OFDM symbols. Referring to Figure 2, each OFDM symbol has a frequency domain of N size、μ grid x*N RB SC It contains multiple subcarriers. Subcarriers can be classified into data subcarriers for transmitting data, reference signal subcarriers for transmitting reference signals, and guard bands. The carrier frequency is also called the center frequency (fc).

[0039] One RB is N in the frequency domain. RB SC It is defined by a sequence of subcarriers (for example, 12). Incidentally, a resource consisting of one OFDM symbol and one subcarrier is called a resource element (RE) or tone. Therefore, one RB is N slot symb *N RB SC It consists of n resource elements. Each resource element in the resource grid is uniquely defined by an index pair (k, l) in a single slot, where k is 0 to N in the frequency domain. size、μ grid x*N RB SC An index given up to -1, where l is in the time domain and ranges from 0 to N. slot symb This is an index given down to -1.

[0040] For a terminal to receive signals from a base station or transmit base station signals, the terminal's time / frequency synchronization must be synchronized with the base station's time / frequency synchronization. This is because, if the base station and the terminal are not synchronized, the terminal cannot determine the time and frequency parameters necessary to demodulate DL signals and transmit UL signals at the correct time.

[0041] Each symbol in a radio frame operating in TDD (time division duplex) or unpaired spectrum consists of at least one of the following: a downlink symbol (DL symbol), an uplink symbol (UL symbol), or a flexible symbol. In FDD (frequency division duplex) or paired spectrum, a radio frame operating on a downlink carrier consists of either a downlink symbol or a flexible symbol, while a radio frame operating on an uplink carrier consists of either an uplink symbol or a flexible symbol. Downlink symbols can be used for downlink transmission but not uplink transmission, and uplink symbols can be used for uplink transmission but not downlink transmission. The use of a flexible symbol in the downlink or uplink is determined by the signal.

[0042] Information regarding the type of each symbol, i.e., whether it is a downlink symbol, uplink symbol, or flexible symbol, consists of a cell-specific (or common) RRC signal. Additionally, information regarding the type of each symbol consists of a UE-specific (or dedicated) RRC signal. The base station uses the cell-specific RRC signal to indicate: i) the period of the cell-specific slot configuration; ii) the number of slots containing only downlink symbols from the beginning of the cell-specific slot configuration period; iii) the number of downlink symbols from the first symbol of the slot immediately following the downlink-only slot; iv) the number of slots containing only uplink symbols from the end of the cell-specific slot configuration period; and v) the number of uplink symbols from the last symbol of the slot immediately preceding the uplink-only slot. Here, a symbol that is neither an uplink nor a downlink symbol is a flexible symbol.

[0043] If the information regarding the symbol type consists of terminal-specific RRC signals, the base station signals, via cell-specific RRC signals, whether the flexible symbol is a downlink symbol or an uplink symbol. At this time, the terminal-specific RRC signals cannot change a downlink symbol or an uplink symbol that consists of cell-specific RRC signals to another symbol type. The specific terminal RRC signals signal, for each slot, the number of downlink symbols among the Nslotsymb symbols of the corresponding slot and the number of uplink symbols among the Nslotsymb symbols of the corresponding slot. At this time, the downlink symbols of a slot are continuously configured from the first symbol to the i-th symbol of the slot. Also, the uplink symbols of a slot are continuously configured from the j-th symbol to the last symbol of the slot (where i < j). In a slot, a symbol that is not configured as either an uplink symbol or a downlink symbol is a flexible symbol.

[0044] The type of symbol consisting of the RRC signals as described above is referred to as a semi-static DL / UL configuration. In the semi-static DL / UL configuration consisting of the RRC signals described above, the flexible symbol is indicated as a downlink symbol, an uplink symbol, or a flexible symbol via the dynamic SFI (slot format information) transmitted on the physical downlink control channel (PDCCH). At this time, a downlink symbol or an uplink symbol consisting of RRC signals is not changed to another symbol type. Table 1 exemplifies the dynamic SFI that the base station indicates to the terminal.

Table 1

[0045] In Table 1, D indicates a downlink symbol, U indicates an uplink symbol, and X indicates a flexible symbol. As shown in Table 1, a maximum of two DL / UL switchings are allowed in one slot.

[0046] Figure 3 illustrates the physical channels used in 3GPP systems (e.g., NR) and a typical signal transmission method utilizing these physical channels.

[0047] When the terminal is powered on or enters a new cell, the terminal performs the initial cell discovery process (S101). Specifically, the terminal synchronizes with the base station during the initial cell discovery. To do this, the terminal receives a primary synchronization signal (PSS) and a secondary synchronization signal (SSS) from the base station to synchronize with the base station and obtain information such as the cell ID. Next, the terminal receives the physical broadcast channel from the base station and obtains broadcast information within the cell.

[0048] After completing the initial cell search, the terminal receives the physical downlink shared channel (PDSCH) via the physical downlink control channel (PDCCH) and the information carried on the PDCCH, thereby obtaining more detailed system information than that acquired through the initial cell search (S102). Here, the system information transmitted to the terminal is the cell common system information necessary for the terminal to operate correctly in the physical layer at the RRC (Radio Resource Control, RRC) layer, and is called remaining system information or system information block (SIB) 1.

[0049] If the terminal first accesses the base station or if there are no radio resources for signal transmission, the terminal performs an arbitrary access process to the base station (S103~S106). First, the terminal transmits a preamble via a physical random access channel (PRACH) (S103), and receives a response message for the preamble from the base station via PDCCH and the corresponding PDSCH (S104). If the terminal receives a valid random access response message, it transmits data including its own identifier to the base station via a physical uplink shared channel (PUSCH) instructed by the uplink grant transmitted from the base station via PDCCH (S105). Next, the terminal waits to receive a PDCCH as instructed by the base station to resolve collisions. If the terminal successfully receives a PDCCH with its own identifier (S106), the random access process ends. During the random access process, the terminal can obtain terminal identification system information at the RRC layer necessary for the terminal to operate correctly at the physical layer. Once the terminal obtains terminal identification system information from the RRC layer, the terminal enters RRC_CONNECTED mode.

[0050] The RRC layer is used for message generation and management for control between terminals and the Radio Access Network (RAN). More specifically, base stations and terminals can use the RRC layer to broadcast cell system information necessary for all terminals in a cell, manage the transmission of paging messages, manage mobility and handover, report and control terminal measurements, and manage and store terminal capabilities, including past performance. Generally, the update of signals transmitted in the RRC layer (hereinafter referred to as RRC signals) is longer than the transmission time interval (i.e., TTI) in the physical layer, so RRC signals can be maintained without change over long periods.

[0051] After the above procedure, the terminal receives PDCCH / PDSCH S107 and transmits the physical uplink shared channel (PUSCH) / physical uplink control channel (PUCCH) S108 as a general uplink / downlink signal transmission procedure. In particular, the terminal receives downlink control information (DCI) via PDCCH. DCI includes control information such as resource allocation information for the terminal. Also, the format of DCI may differ depending on its intended use. Uplink control information (UCI) transmitted by the terminal to the base station via the uplink includes downlink / uplink ACK / NACK signals, CQI (channel quality indicator), PMI (precoding matrix index), RI (rank indicator), etc. Here, CQI, PMI, and RI are included in CSI (channel state information). In the case of a 3GPP NR system, the terminal transmits the above-mentioned HARQ-ACK and control information such as CSI via PUSCH and / or PUCCH.

[0052] Figure 4 shows the SS / PBCH block for initial cell access in a 3GPP NR system.

[0053] When a terminal is powered on or attempts to access a new cell, it acquires time and frequency synchronization with the cell and performs an initial cell discovery process. During the cell discovery process, the terminal detects the cell's physical cell identity (NcellID). To do this, the terminal receives synchronization signals from the base station, such as the primary synchronization signal (PSS) and secondary synchronization signal (SSS), to synchronize with the base station. At this time, the terminal acquires information such as the cell identifier (identity, ID).

[0054] Refer to Figure 4(a) for a more detailed explanation of the synchronization signal (SS). The synchronization signal is divided into PSS and SSS. PSS is used to obtain time-domain synchronization and / or frequency-domain synchronization, such as OFDM symbol synchronization and slot synchronization. SSS is used to obtain frame synchronization and cell group ID. Referring to Figure 4(a) and Table 2, an SS / PBCH block consists of 20 RBs (=240 subcarriers) consecutively on the frequency axis and 4 OFDM symbols consecutively on the time axis. In this case, within the SS / PBCH block, the PSS is transmitted via subcarriers 56-182 in the first OFDM symbol, and the SSS is transmitted via subcarriers 56-182 in the third OFDM symbol. Here, the lowest subcarrier index of the SS / PBCH block is assigned starting from 0. In the first OFDM symbol on which the PSS is transmitted, the base station does not transmit signals via the remaining subcarriers, i.e., subcarriers 0-55 and 183-239. Furthermore, in the third OFDM symbol in which the SSS is transmitted, the base station does not transmit signals via subcarriers 48-55 and 183-191. In the SS / PBCH block, the base station transmits the PBCH (physical broadcast channel) via the remaining REs excluding the aforementioned signals. [Table 2]

[0055] SS generates a total of 1008 unique physical layer cell IDs through combinations of three PSSs and SSSs. More specifically, each physical layer cell ID is part of only one physical layer cell identifier group, and each group is grouped into 336 physical layer cell identifier groups, each containing three unique identifiers. Therefore, physical layer cell ID N cell ID =3N (1) ID +N (2) ID This is an index N ranging from 0 to 335 that indicates a physical-hierarchical cell-identifier group.(1) ID And, an index N from 0 to 2 indicating a physical-hierarchical identifier within the physical-hierarchical cell-identifier group. (2) ID It is uniquely defined by [the system]. The terminal detects the PSS and identifies one of three unique physical-hierarchy identifiers. The terminal also detects the SSS and identifies one of 336 physical-hierarchy cell IDs associated with the physical-hierarchy identifier. In this case, the sequence d of the PSS PSS (n) is the following number 1.

number

number

number

number

number

number

[0056] A 10ms long wireless frame is divided into two 5ms long half-frames. Refer to Figure 4(b) to describe the slot in which the SS / PBCH block is transmitted within each half-frame. The slot in which the SS / PBCH block is transmitted is one of cases A, B, C, D, or E. In case A, the subcarrier spacing is 15kHz, and the start of the SS / PBCH block is at the {2, 8} + 14*n symbol. In this case, n=0, 1 at carrier frequencies below 3GHz. Also, n=0, 1, 2, 3 at carrier frequencies above 3GHz and below 6GHz. In case B, the subcarrier spacing is 30kHz, and the start of the SS / PBCH block is at the {4, 8, 16, 20} + 28*n symbol. In this case, n=0 at carrier frequencies below 3GHz. Also, n=0, 1 at carrier frequencies above 3GHz and below 6GHz. In Case C, the subcarrier spacing is 30 kHz, and the SS / PBCH block starts at the {2nd, 8th} + 14*nth symbol. In this case, for carrier frequencies below 3 GHz, n=0, 1. Also, for carrier frequencies above 3 GHz and below 6 GHz, n=0, 1, 2, 3. In Case D, the subcarrier spacing is 120 kHz, and the SS / PBCH block starts at the {4th, 8th, 16th, 20th} + 28*nth symbol. In this case, for carrier frequencies above 6 GHz, n=0, 1, 2, 3, 5, 6, 7, 8, 10, 11, 12, 13, 15, 16, 17, 18. In Case E, the subcarrier spacing is 240 kHz, and the SS / PBCH block starts at the {8th, 12th, 16th, 20th, 32nd, 36th, 40th, 44th} + 56*nth symbol. In this case, at carrier frequencies of 6 GHz or higher, n = 0, 1, 2, 3, 5, 6, 7, 8.

[0057] Figure 5 shows the procedure for transmitting control information and control channels in a 3GPP NR system. Referring to Figure 5(a), the base station adds a CRC (cyclic redundancy check) masked (e.g., by XOR operation) with an RNTI (radio network temporary identifier) ​​to the control information (e.g., DCI) S202. The base station scrambles the CRC with an RNTI value determined according to the purpose / target of each piece of control information. A common RNTI used by one or more terminals includes at least one of the following: SI-RNTI (system information RNTI), P-RNTI (paging RNTI), RA-RNTI (random access RNTI), and TPC-RNTI (transmit power control RNTI). Furthermore, each terminal-specific RNTI includes at least one of the following: C-RNTI (cell temporary RNTI), CS-RNTI, or MCS-C-RNTI. Next, after the base station performs channel encoding (e.g., polar coding) in S204, it performs rate-matching in S206 to match the amount of resources used for PDCCH transmission. Next, the base station multiplexes DCIs (e.g.) based on the CCE (control channel element)-based PDCCH structure in S208. The base station also applies additional processes S210 to the multiplexed DCIs (e.g., scrambling, modulation (e.g., QPSK), interleaving, etc., before mapping them to the resources to be transmitted. A CCE is the basic resource unit for PDCCH, and one CCE consists of multiple (e.g., 6) REGs (resource element groups). One REG consists of multiple (e.g., 12) REs. The number of CCEs used for one PDCCH is defined as the aggregation level. The 3GPP NR system uses 1, 2, 4, 8, or 16 integrated levels.Figure 5(b) is a diagram relating to the CCE integration level and PDCCH multiplexing, showing the types of CCE integration levels used for a single PDCCH and the CCEs transmitted in the control domain thereunder.

[0058] Figure 6 shows the CORESET (control resource set) to which the PDCCH (physical downlink control channel) can be transmitted in a 3GPP NR system.

[0059] A CORESET is a time-frequency resource through which PDCCH, a control signal for a terminal, is transmitted. Furthermore, the search space, described later, is mapped to a single CORESET. Therefore, instead of monitoring the entire frequency band to receive PDCCH, the terminal monitors the CORESET and the designated time-frequency domain to decode the PDCCH mapped to the CORESET. A base station configures one or more CORESETs for each cell in the terminal. A CORESET consists of up to three consecutive symbols on the time axis. A CORESET also consists of six consecutive PRB units on the frequency axis. In the embodiment shown in Figure 5, CORESET#1 consists of consecutive PRBs, while CORESET#2 and CORESET#3 consist of discontinuous PRBs. A CORESET can be located at any symbol within a slot. For example, in the embodiment shown in Figure 5, CORESET#1 starts at the first symbol in the slot, CORESET#2 starts at the fifth symbol in the slot, and CORESET#9 starts at the ninth symbol in the slot.

[0060] Figure 7 shows how to configure the PDCCH search space in a 3GPP NR system.

[0061] To transmit PDCCH to a terminal, each CORESET has at least one search space. In embodiments of the present invention, the search space is a collection of all time-frequency resources (hereinafter referred to as PDCCH candidates) to which the terminal's PDCCH is transmitted. The search space includes a common search space that all 3GPP NR terminals should search in common, and a terminal-specific or UE-specific search space that a specific terminal should search. In the common search space, PDCCHs that all terminals in a cell belonging to the same base station are set to search in common are monitored. In addition, terminal-specific search spaces are set up terminal by terminal to monitor the PDCCH assigned to each terminal at different locations in the search space depending on the terminal. In the case of terminal-specific search spaces, due to the limited control area to which PDCCHs are assigned, the search spaces between terminals may be partially overlapping. Monitoring PDCCHs includes blind decoding of PDCCH candidates in the search space. If blind decoding is successful, it is expressed as the PDCCH being (successfully) detected / received. If blind decoding fails, it is expressed as the PDCCH not being detected / received, or not being successfully detected / received.

[0062] For the sake of explanation, a PDCCH scrambled with a group common (GC) RNTI already known by one or more terminals for the purpose of transmitting downlink control information to one or more terminals is referred to as a group common (GC) PDCCH or common PDCCH. Furthermore, a PDCCH scrambled with a terminal-specific RNTI already known by a specific terminal for the purpose of transmitting uplink scheduling information or downlink scheduling information to a specific terminal is referred to as a terminal-specific PDCCH. The common PDCCH is included in the common search space, and the terminal-specific PDCCH is included in either the common search space or the terminal-specific PDCCH.

[0063] The base station informs each terminal or group of terminals via the PDCCH about resource allocation information for the transmission channels PCH (paging channel) and DL-SCH (downlink-shared channel) (i.e., DL Grant), or information about UL-SCH resource allocation and HARQ (hybrid automatic repeat request) (i.e., UL Grant). The base station transmits PCH transmission blocks and DL-SCH transmission blocks via the PDSCH. The base station transmits data excluding specific control information or specific service data via the PDSCH. The terminal also receives data excluding specific control information or specific service data via the PDSCH.

[0064] The base station transmits the PDCCH containing information about which terminals (one or more terminals) the PDSCH data will be transmitted to and how those terminals should receive and decode the PDSCH data. For example, suppose a DCI transmitted via a specific PDCCH is CRC masked with an RNTI named "A", and that DCI indicates that the PDSCH is assigned to a radio resource (e.g., frequency location) named "B", and indicates transmission format information (e.g., transmission block size, modulation scheme, coding information, etc.) named "C". Terminals monitor the PDCCH using their own RNTI information. In this case, if a terminal blind-decodes the PDCCH using the "A" RNTI, that terminal will receive the PDCCH and, through the information of the received PDCCH, receive the PDSCH indicated by "B" and "C".

[0065] Table 3 shows one example of PUCCH used in a wireless communication system. [Table 3]

[0066] PUCCH is used to transmit the following uplink control information (UCI):

[0067] -SR (Scheduling Request): This is information used to request uplink UL-SCH resources.

[0068] -HARQ-ACK: A response to a PDCCH (indicating a DL SPS release) and / or to an uplink transmission block (TB) on a PDSCH. HARQ-ACK indicates whether information transmitted via the PDCCH or PDSCH has been received. HARQ-ACK responses include positive ACK (simply ACK), negative ACK (hereinafter NACK), DTX (Discontinuous Transmission), or NACK / DTX. Here, the term HARQ-ACK is used interchangeably with HARQ-ACK / NACK and ACK / NACK. Generally, ACK is represented by a bit value of 1 and NACK is represented by a bit value of 0.

[0069] -CSI: This is feedback information for the downlink channel. It is generated by the terminal based on the CSI-RS (Reference Signal) transmitted by the base station. MIMO (multiple input multiple output) related feedback information includes RI and PMI. CSI is divided into CSI Part 1 and CSI Part 2 depending on the information it indicates.

[0070] The 3GPP NR system uses five PUCCH formats to support diverse service scenarios, diverse channel environments, and frame structures.

[0071] PUCCH format 0 is a format for transmitting 1-bit or 2-bit HARQ-ACK information or SR. PUCCH format 0 is transmitted via one or two OFDM symbols on the time axis and one RB on the frequency axis. If PUCCH format 0 is transmitted via two OFDM symbols, the same sequence is transmitted to the two symbols with different RBs. Through this, the terminal obtains a frequency diversity gain. More specifically, the terminal is M bit Bit UCI(M bit The value of the cyclic shift m depends on whether it is =1 or 2. cs Determine the base sequence of length 12 and set the value m cs The cyclically shifted sequence is mapped to 12 REs, consisting of one OFDM symbol and one PRB, and transmitted. The terminal has 12 cyclic shifts available, M bit If = 1, then 1-bit UCI0 and 1 represent a sequence of two cyclic shifts with a difference of 6 in cyclic shift values. Also, M bit If = 2, then the 2-bit UCI00, 01, 11, and 10 represent a sequence of four cyclic shifts where the difference in cyclic shift values ​​is 3.

[0072] PUCCH format 1 transmits 1-bit or 2-bit HARQ-ACK information or SR. PUCCH format 1 is transmitted via a continuous sequence of OFDM symbols on the time axis and a single PRB on the frequency axis. Here, the number of OFDM symbols occupied by PUCCH format 1 is one of 4 to 14. For more details, see M bit UCI with =1 is modulated by BPSK. The terminal is M bitThe UCI, which is equal to 2, is modulated using QPSK (quadrature phase shift keying). A signal is obtained by multiplying the modulated complex valued symbol d(0) by a sequence of length 12. The terminal transmits the obtained signal by spreading it with time-axis OCC (orthogonal cover code) to the even-numbered OFDM symbols to which PUCCH format 1 is assigned. The maximum number of different terminals that can be multiplexed with the same RB is determined by the length of the OCC used in PUCCH format 1. The DMRS (demodulation reference signal) is spread with OCC and mapped to the odd-numbered OFDM symbols of PUCCH format 1.

[0073] PUCCH format 2 can transmit UCIs of more than 2 bits. PUCCH format 2 can be transmitted through one or two OFDM symbols on the time axis and one or more RBs on the frequency axis. When PUCCH format 2 is transmitted through two OFDM symbols, the same sequence may be transmitted in the two OFDM symbols through different RBs. Here, the sequence is a plurality of modulated complex number symbols d(0), ..., d(M symbol -1) is acceptable. Here, M symbol is M bit / 2 is sufficient. This allows the terminal to obtain frequency diversity gain. More specifically, M bit Bit UCI(M bit >2) is bit-level scrambled, QPSK modulated, and mapped to RBs of one or two OFDM symbols, where the number of RBs may be any one from 1 to 16.

[0074] PUCCH format 3 or PUCCH format 4 transmits UCIs exceeding 2 bits. PUCCH format 3 or PUCCH format 4 is transmitted via continuous OFDM symbols on the time axis and one PRB on the frequency axis. The number of OFDM symbols occupied by PUCCH format 3 or PUCCH format 4 is one of 4 to 14. For more details, see the terminal. bit Bit UCI(M bit >2) Modulate with π / 2-BPSK (Binary Phase Shift Keying) or QPSK, and complex number symbols d(0)~d(M symb -1) is generated. Here, if we use π / 2-BPSK, M symb =M bit And, if you use QPSK, symb =M bit The value is / 2. The terminal does not apply block-unit spreading to PUCCH format 3. However, the terminal may apply block-unit spreading to one RB (i.e., 12 subcarriers) using a PreDFT-OCC of length -12 so that PUCCH format 4 has two or four multiplexing capacities. The terminal transmits the spread signal by transmit precoding (or DFT-precoding) and mapping it to each RE.

[0075] In this case, the number of RBs occupied by PUCCH format 2, PUCCH format 3, or PUCCH format 4 is determined according to the length of the UCI transmitted by the terminal and the maximum code rate. If the terminal uses PUCCH format 2, it transmits both HARQ-ACK information and CSI information via PUCCH. If the number of RBs that the terminal can transmit is greater than the maximum number of RBs that PUCCH format 2, PUCCH format 3, or PUCCH format 4 can use, the terminal will not transmit some of the UCI information according to the priority of the UCI information, and will transmit only the remaining UCI information.

[0076] PUCCH format 1, PUCCH format 3, or PUCCH format 4 is configured via an RRC signal to instruct frequency hopping within a slot. When frequency hopping is configured, the index of the RB to be frequency-hopped is determined by the RRC signal. If PUCCH format 1, PUCCH format 3, or PUCCH format 4 is transmitted over N OFDM symbols in the time axis, the first hop will have floor(N / 2) OFDM symbols, the second hop will have ceil(N / 2) OFDM symbols.

[0077] PUCCH format 1, PUCCH format 3, or PUCCH format 4 are configured to be repeatedly transmitted to multiple slots. In this case, the number K of slots to which the PUCCH is repeatedly transmitted is determined by the RRC signal. The repeatedly transmitted PUCCH should start from the same OFDM symbol in the same position within each slot and have the same length. If any of the OFDM symbols in a slot to which the terminal is to transmit the PUCCH is indicated as a DL symbol by the RRC signal, the terminal does not transmit the PUCCH from that slot but postpones transmission to the next slot.

[0078] On the other hand, in the 3GPP NR system, terminals transmit and receive using a bandwidth smaller than or equal to the carrier (or cell) bandwidth. For this purpose, terminals are configured with a bandwidth part (BWP) consisting of a continuous portion of the carrier bandwidth. Terminals operating according to TDD or in the ampered spectrum have up to four DL / UL BWP pairs per carrier (or cell). The terminal also activates one DL / UL BWP pair. Terminals operating according to FDD or in the paired spectrum have up to four DL BWPs configured on the downlink carrier (or cell) and up to four UL BWPs configured on the uplink carrier (or cell). The terminal activates one DL BWP and one UL BWP per carrier (or cell). The terminal does not need to receive or transmit from time-frequency resources other than the activated BWPs. The activated BWPs are referred to as active BWPs.

[0079] The base station refers to the activated BWP among the configured BWPs of a terminal as the DCI. The BWP indicated by the DCI is activated, and the other configured BWPs are deactivated. In a carrier (or cell) operating in TDD mode, the base station includes a BPI (bandwidth part indicator) in the DCI that schedules the PDSCH or PUSCH to indicate which BWP to activate in order to change the terminal's DL / UL BWP pair. The terminal receives the DCI that schedules the PDSCH or PUSCH and identifies the DL / UL BWP pair to activate based on the BPI. In the case of a downlink carrier (or cell) operating in FDD mode, the base station includes a BPI informing the DCI that schedules the PDSCH which BWP to activate in order to change the terminal's DL BWP. In the case of an uplink carrier (or cell) operating in FDD mode, the base station includes a BPI informing the DCI that schedules the PUSCH which BWP to activate in order to change the terminal's UL BWP.

[0080] Figure 8 is a conceptual diagram illustrating career integration.

[0081] Carrier aggregation refers to a method used by wireless communication systems to utilize a wider frequency band by having terminals use multiple frequency blocks, or (logical) cells, consisting of uplink resources (or component carriers) and / or downlink resources (or component carriers), within a single larger logical frequency band. For convenience of explanation, the term "component carrier" will be used consistently below.

[0082] Referring to Figure 8, as an example of a 3GPP NR system, the overall system bandwidth includes up to 16 component carriers, each component carrier having a bandwidth of up to 400 MHz. Each component carrier includes one or more physically consecutive subcarriers. Although Figure 8 shows each component carrier having the same bandwidth, this is merely illustrative, and each component carrier may have different bandwidths. Also, although each component carrier is shown as being adjacent to each other on the frequency axis, the diagram is a logical representation, and each component carrier may be physically adjacent to or far from each other.

[0083] Each component carrier uses a different center frequency. Furthermore, physically adjacent component carriers share a single common center frequency. In the embodiment shown in Figure 8, assuming all component carriers are physically adjacent, center frequency A is used for all component carriers. If we assume that the component carriers are not physically adjacent, then center frequencies A and B are used for each component carrier.

[0084] When the overall system bandwidth is expanded through carrier aggregation, the frequency band used for communication with each terminal is defined on a component carrier basis. Terminal A uses the overall system bandwidth of 100 MHz and communicates using all five component carriers. Terminals B1 to B5 use only a 20 MHz bandwidth and communicate using one component carrier each. Terminals C1 and C2 use only a 40 MHz bandwidth and communicate using two component carriers each. The two component carriers may be logically / physically adjacent or not. In the embodiment shown in Figure 8, terminal C1 uses two non-adjacent component carriers, and terminal C2 uses two adjacent component carriers.

[0085] Figure 9 is a diagram illustrating terminal carrier communication and multiple carrier communication. Specifically, Figure 9(a) shows the subframe structure of a single carrier, and Figure 9(b) shows the subframe structure of a multiple carrier.

[0086] Referring to Figure 9(a), a typical wireless communication system, in FDD mode, transmits or receives data via one DL band and its corresponding UL band. In other specific embodiments, in TDD mode, the wireless communication system divides the wireless frame into uplink time units and downlink time units in the time domain, and transmits or receives data via the uplink / downlink time units. Referring to Figure 9(b), three 20MHz component carriers (CCs) are aggregated in both the UL and DL bands, supporting a 60MHz bandwidth. Each CC is either adjacent or non-adjacent to the others in the frequency domain. For convenience, Figure 9(b) shows a symmetrical case where the bandwidths of the UL CCs and DL CCs are the same, but the bandwidths of each CC may be determined independently. Asymmetric carrier aggregations with different numbers of UL CCs and DL CCs are also possible. A DL / UL CC assigned / configured to a specific terminal via RRC is referred to as the serving DL / UL CC of that terminal.

[0087] A base station communicates with a terminal by activating some or all of the terminal's serving CCs, or by deactivating some of the CCs. The base station may change which CCs are activated / deactivated, or change the number of CCs that are activated / deactivated. Once a base station assigns available CCs to a terminal on a cell-specific or terminal-specific basis, at least one of the initially assigned CCs does not need to be deactivated unless the CC assignments for the terminal are completely reconfigured or the terminal is handed over. The CC that is not deactivated by the terminal is called the primary CC (PCC) or PCell (primary cell), and the CC that the base station can freely activate / deactivate is called the secondary CC (SCC) or SCell (secondary cell).

[0088] On the other hand, 3GPP NR uses the concept of a cell to manage radio resources. A cell is defined as a combination of downlink and uplink resources, i.e., a combination of DL CC and UL CC. A cell consists of a DL resource alone, or a combination of DL and UL resources. If carrier aggregation is supported, the linkage between the carrier frequency of the DL resource (or DL ​​CC) and the carrier frequency of the UL resource (or UL CC) is indicated by system information. Carrier frequency refers to the center frequency of each cell or CC. A cell corresponding to a PCC is called a PCell, and a cell corresponding to an SCC is called a SCell. In the downlink, the carrier corresponding to a PCell is a DL PCC, and in the uplink, the carrier corresponding to a PCell is a UL PCC. Similarly, in the downlink, the carrier corresponding to a SCell is a DL SCC, and in the uplink, the carrier corresponding to a SCell is a UL SCC. Depending on the terminal capacity, a serving cell consists of one PCell and zero or more SCells. If the RRC_CONNECTED state exists but carrier aggregation is not configured, or if the UE does not support carrier aggregation, there will be only one serving cell consisting solely of PCells.

[0089] As described above, the term "cell" used in carrier aggregation is distinct from the term "cell" which refers to a specific geographical area where communication services are provided by a single base station or antenna group. However, in order to distinguish between a cell referring to a specific geographical area and a cell in carrier aggregation, in this invention, a cell in carrier aggregation is referred to as CC, and a cell referring to a geographical area is referred to as cell.

[0090] Figure 10 shows an example where the cross-carrier scheduling technique is applied. Once cross-carrier scheduling is set up, the control channel transmitted via the first CC uses the carrier indicator field (CIF) to schedule the data channel transmitted via the first or second CC. The CIF is contained within the DCI. In other words, a scheduling cell is set up, and DL grants / UL grants transmitted from the PDCCH region of the scheduling cell schedule the PDSCH / PUSCH of the scheduled cell. That is, the PDCCH region of the scheduling cell is a search area for multiple component carriers. A PCell is essentially a scheduling cell, and a specific SCell is designated as a scheduling cell by a higher hierarchy.

[0091] In the embodiment shown in Figure 10, we assume that three DL CCs are merged. Here, DL component carrier #0 is assumed to be a DL PCC (or PCell), and DL component carriers #1 and #2 are assumed to be DL SCCs (or SCells). We also assume that the DL PCC is configured as a PDCCH monitoring CC. If cross-carrier scheduling is not configured by terminal-specific (or terminal-group-specific, or cell-specific) higher-level signaling, the CIF will be disabled, and each DL CC will transmit only PDCCHs that schedule their own PDSCHs without a CIF according to the NR PDCCH rule (non-cross-carrier scheduling, self-carrier scheduling). In contrast, if cross-carrier scheduling is configured through terminal-specific (or terminal-group-specific, or cell-specific) higher-level signaling, CIF becomes enabled, and a specific CC (e.g., DL PCC) uses CIF to transmit not only PDCCHs that schedule PDSCHs of DL CC A, but also PDCCHs that schedule PDSCHs of other CCs (cross-carrier scheduling). In contrast, other DL CCs do not transmit PDCCHs. Therefore, depending on whether cross-carrier scheduling is configured for the terminal, the terminal either monitors PDCCHs without CIFs and receives self-carrier scheduled PDSCHs, or monitors PDCCHs with CIFs and receives cross-carrier scheduled PDSCHs.

[0092] On the other hand, Figures 9 and 10 illustrate the subframe structure of a 3GPP LTE-A system, and the same or similar configurations are applicable to a 3GPP NR system. However, in a 3GPP NR system, the subframes in Figures 9 and 10 are switched to slots.

[0093] Figure 11 shows the configuration of a code block group (CBG) according to an embodiment of the present invention and its time-frequency resource mapping. More specifically, Figure 11(a) shows one embodiment of a CBG configuration included in a single transmission block (TB), and Figure 11(b) shows the time-frequency resource mapping of the said CBG configuration.

[0094] Channel codes have a defined maximum supported length. For example, the maximum supported length of Turbo Code used in 3GPP LTE(-A) is 6144 bits. However, the length of a transmission block (TB) transmitted in a PDSCH may be longer than 6144 bits. If the length of a TB is longer than the maximum supported length, the TB is divided into code blocks (CBs) of up to 6144 bits in length. Each CB is the unit in which channel coding is performed. Furthermore, for efficient retransmission, several CBs may be bundled together to form a CBG. Terminals and base stations need information on how the CBG is configured.

[0095] Within a TB, CBGs and CBs can be configured in various ways. In one embodiment, the number of available CBGs is determined to a fixed value, or configured as RRC configuration information between the base station and the terminal. In this case, the number of CBs is determined according to the length of the TB, and the CBGs are set according to the determined number information. In another embodiment, the number of CBs contained in a single CBG may be determined to a fixed value, or configured as RRC configuration information between the base station and the terminal. In this case, if the number of CBs is determined according to the length of the TB, the number of CBGs is set according to the number of CBs per CBG information.

[0096] Referring to the embodiment in Figure 11(a), one TB is divided into eight CBs. The eight CBs are further bundled into four CBGs. Such a mapping relationship between CBs and CBGs (or CBG configuration) is set statically between the base station and the terminal, or semi-statically as RRC configuration information. According to other embodiments, the mapping relationship is set via dynamic signaling. When the terminal receives the PDCCH transmitted by the base station, the terminal directly or indirectly identifies the mapping relationship between CBs and CBGs (or CBG configuration) through explicit and / or implicit information. A single CBG may contain only one CB, or it may contain all the CBs that constitute a single TB. Incidentally, the technique proposed in the embodiments of the present invention is applicable regardless of the configuration of CBs and CBGs.

[0097] Referring to Figure 11(b), the CBGs constituting a single TB are mapped to the time-frequency resources scheduled by the PDSCH. According to one embodiment, each CBG is first assigned to the frequency axis and then extended to the time axis. If a PDSCH consisting of one TB containing four CBGs is assigned to seven OFDM symbols, then CBG0 is transmitted over the first and second OFDM symbols, CBG1 is transmitted over the second, third, and fourth OFDM symbols, CBG2 is transmitted over the fourth, fifth, and sixth OFDM symbols, and CBG3 is transmitted over the sixth and seventh OFDM symbols. Such time-frequency mapping relationships assigned between CBGs and PDSCHs are determined between terminals. However, the mapping relationships shown in Figure 11(b) are one embodiment for illustrating the present invention, and the techniques proposed in the embodiments of the present invention may be applied independently of the time-frequency mapping relationships of the CBGs.

[0098] Figure 12 illustrates the process by which a base station performs TB-based transmission or CBG-based transmission, and a terminal transmits a HARQ-ACK in response. Referring to Figure 12, the base station configures a transmission method suitable for the terminal, either TB-based transmission or CBG-based transmission. The terminal transmits HARQ-ACK information bits(s) according to the transmission method configured by the base station via PUCCH or PUSCH. The base station configures a PDCCH to schedule the PDSCH to be transmitted to the terminal. The PDCCH schedules TB-based transmission and / or CBG-based transmission. For example, one TB or two TBs are scheduled in the PDCCH. If one TB is scheduled, the terminal should feed back a 1-bit HARQ-ACK. If two TBs are scheduled, the terminal should feed back a 2-bit HARQ-ACK for each of the two TBs. To eliminate ambiguity between the base station and the terminal, there is a predetermined order between each information bit of the 2-bit HARQ-ACK and the two TBs. Incidentally, if the MIMO transmission rank or layer is low, one TB is transmitted through one PDSCH, and if the MIMO transmission rank or layer is high, two TBs are transmitted through one PDSCH.

[0099] The terminal transmits a 1-bit TB-based HARQ-ACK per TB to inform the base station of the success or failure of each TB's reception. To generate a HARQ-ACK for a TB, the terminal checks for reception errors for that TB via TB-CRC. If the TB-CRC check for a TB is successful, the terminal generates an ACK for the TB's HARQ-ACK. However, if a TB-CRC error occurs for a TB, the terminal generates a NACK for the TB's HARQ-ACK. The terminal transmits these generated TB-based HARQ-ACKs to the base station. The base station retransmits the TBs for which a NACK was responded from the TB-based HARQ-ACKs received from the terminal.

[0100] Furthermore, the terminal transmits a 1-bit CBG-based HARQ-ACK for each CBG to inform the base station of the success or failure of reception for each CBG. To generate a HARQ-ACK for a single CBG, the terminal decodes all CBs included in the CBG and checks for reception errors for the relevant CBs via CB-CRC. If the terminal successfully receives all CBs constituting a single CBG (i.e., if all CB-CRC checks are successful), the terminal generates an ACK for the HARQ-ACK of that CBG. However, if the terminal fails to receive at least one of the CBs constituting a single CBG (i.e., if at least one CB-CRC error occurs), the terminal generates a NACK for the HARQ-ACK of that CBG. The terminal transmits these generated CBG-based HARQ-ACKs to the base station. The base station retransmits the CBGs for which a NACK was responded from the CBG-based HARQ-ACKs received from the terminal. According to one embodiment, the CB configuration of the retransmitted CBG is the same as the CB configuration of the conventionally transmitted CBG. The length of the CBG-underlying HARQ-ACK information bits transmitted by the terminal to the base station is determined based on the number of CBGs transmitted via the PDSCH, or the maximum number of CBGs consisting of RRC signals.

[0101] On the other hand, even if a terminal successfully receives all CBGs contained in a TB, a TB-CRC error may still occur for that TB. In this case, the terminal performs CBG-board HARQ-ACK flipping to request retransmission for the TB. In other words, even though the terminal successfully received all CBGs contained in the TB, it may generate NACKs for all CBG-board HARQ-ACK information bits. A base station that receives a CBG-board HARQ-ACK feedback in which all HARQ-ACK information bits are NACKs will retransmit all of the TB and CBGs.

[0102] According to an embodiment of the present invention, CBG-based HARQ-ACK feedback is used to ensure successful transmission of TB. The base station instructs the terminal to transmit CBG-based HARQ-ACK. In this case, a retransmission technique using CBG-based HARQ-ACK is used. CBG-based HARQ-ACK is transmitted via PUCCH. Alternatively, if UCI is configured to be transmitted via PUCCH, CBG-based HARQ-ACK may be transmitted via the corresponding PUCCH. In PUCCH, the setting of HARQ-ACK resources is configured via RRC signals. Furthermore, the HARQ-ACK resources to be actually transmitted are indicated via PDCCH, which schedules PDSCH transmitted in the CBG-based system. The terminal transmits HARQ-ACK(etc.) regarding the success or failure of receiving the transmitted CBG via one or more PUCCH resources indicated via PDCCH from among the PUCCH resources consisting of RRC.

[0103] The base station identifies whether a terminal has successfully received a CBG(etc.) transmitted to it via the terminal's CBG-based HARQ-ACK feedback. In other words, the base station recognizes which CBG(etc.) the terminal has successfully received and which it has failed to receive, based on the HARQ-ACK received for each CBG from the terminal. The base station then retransmits the CBGs based on the received CBG-based HARQ-ACK. More specifically, the base station bundles and retransmits only the CBG(etc.) that received a failed HARQ-ACK in a single TB. At this time, CBG(etc.) that received a successful HARQ-ACK are excluded from the retransmission. The base station then schedules the retransmitted CBG(etc.) into a single PDSCH and transmits them to the terminal.

[0104] <Communication methods in unlicensed frequency bands>

[0105] Figure 13 illustrates an NR-U service environment.

[0106] Referring to Figure 13, a service environment is provided to the user that combines NR technology 11 in the licensed band and NR technology 12 in the unlicensed band, which is NR-U. For example, in an NR-U environment, NR technology 11 in the licensed band and NR technology 12 in the unlicensed band are integrated using technologies such as carrier aggregation, which contributes to expanding network capacity. Furthermore, in an asymmetric traffic structure where there is more downlink data than uplink data, NR-U provides NR services optimized to diverse requirements and environments. For convenience, NR technology in the licensed band is referred to as NR-L (NR-Licensed), and NR technology in the unlicensed band is referred to as NR-U.

[0107] Figure 14 shows one example of a terminal and base station placement scenario in an NR-U service environment. Due to the high-frequency characteristics of the NR-U service environment and its target frequency band, the wireless communication range is not long. Considering this, in an environment where conventional NR-L services and NR-U services coexist, the terminal and base station placement scenario is either an overlay model or a co-located model.

[0108] In the overlay model, a macro base station uses licensed band carriers to wirelessly communicate with X and X' terminals within the macro region 32 and is connected to multiple RRHs (Radio Remote Heads) via an X2 interface. Each RRH uses unlicensed band carriers to wirelessly communicate with X or X' terminals within a certain region 31. The frequency bands of the macro base station and the RRHs are different and do not interfere with each other, but fast data exchange should take place between the macro base station and the RRHs via the X2 interface in order to use NR-U services as a supplementary downlink channel for NR-L services via carrier aggregation.

[0109] In the co-located model, pico / femtobase stations use both licensed and unlicensed band carriers simultaneously to communicate wirelessly with Y terminals. However, the use of both NR-L and NR-U services by pico / femtobase stations is limited to downlink transmission. The coverage 33 of NR-L services and the coverage 34 of NR-U services may vary depending on the frequency band, transmission power, etc.

[0110] When NR communication is performed in an unlicensed band, conventional equipment communicating in that band (for example, wireless LAN (Wi-Fi equipment)) cannot demodulate NR-U messages or data. Therefore, conventional equipment treats NR-U messages or data as a type of energy and performs interference avoidance operations using energy detection techniques. In other words, if the energy corresponding to an NR-U message or data is less than -62 dBm or a specific ED (Energy Detection) critical value, wireless LAN equipment will ignore the message or data and communicate. As a result, terminals performing NR communication in an unlicensed band may frequently experience interference from wireless LAN equipment.

[0111] Therefore, in order to effectively implement NR-U technology / service, it is necessary to allocate or reserve a specific frequency band during a specific period of time. However, there is a problem in that efficient NR-U service is difficult because peripheral equipment communicating via unlicensed bands attempts to access them based on energy detection techniques. Therefore, in order for NR-U technology to take root, research should be prioritized on coexistence methods with conventional unlicensed band equipment and methods for efficiently sharing radio channels. In other words, a robust mechanism should be developed so that NR-U equipment does not affect conventional unlicensed band equipment.

[0112] Figure 15 shows a conventional communication method (e.g., wireless LAN) that operates in an unlicensed bandwidth. Most devices operating in an unlicensed bandwidth operate on an LBT (Listen-Before-Talk) basis, and therefore perform Clear Channel Assessment (CCA) to sense the channel before transmitting data.

[0113] Referring to Figure 15, wireless LAN devices (e.g., APs, STAs) perform carrier sensing before transmitting data to check if a channel is busy. If a wireless signal of a certain strength or higher is detected on the channel to which data is to be transmitted, the channel is determined to be busy, and the wireless LAN device delays access to that channel. This process is called clear channel evaluation, and the level at which a signal is detected is called the CCA threshold. On the other hand, if no wireless signal is detected on the channel, or if a wireless signal with an intensity lower than the CCA threshold is detected, the channel is determined to be idle.

[0114] If a channel is determined to be idle, terminals with data to transmit will perform a defer duration (e.g., AIFS (Arbitration InterFrame Space), PIFS (PCF IFS)) followed by a backoff procedure. The defer duration is the minimum time a terminal must wait after a channel becomes idle. The backoff procedure causes terminals to wait for an arbitrary amount of time after the defer duration expires. For example, a terminal waits within a Contention Window (CW) while the channel is idle, decreasing its slot time by a random number assigned to it. Once a terminal has exhausted all its slot time, it attempts to access the channel.

[0115] If channel access is successful, the terminal transmits data through the channel. If data transmission is successful, the competition window size (CWS) is reset to its initial value (CWmin). Conversely, if data transmission fails, the CWS doubles. As a result, the terminal is assigned a new random number within twice the previous random number range and performs the backoff procedure in the next CW. In wireless LANs, only ACK is defined as the received response information for data transmission. Therefore, if an ACK is received for data transmission, the CWS is reset to its initial value, and if no feedback information is received for data transmission, the CWS doubles.

[0116] As mentioned above, since most communications in conventional unlicensed bands operate on an LBT (Low-Block Test) basis, channel access in NR-U systems also uses LBT to coexist with conventional equipment. In detail, channel access methods on unlicensed bands in NR are classified into the following four categories depending on the presence / absence and application method of LBT.

[0117] ●Category 1: No LBT

[0118] -Tx entities do not perform LBT procedures for transmission.

[0119] ●Category 2: LBT without random backoff

[0120] -The Tx entity senses whether the channel is idle during the first interval without random backoff in order to perform a transmission. That is, immediately after the Tx entity senses that the channel is idle during the first interval, it performs a transmission through that channel. The first interval is a preset interval of length immediately before the Tx entity performs a transmission. In one embodiment, the first interval may be an interval of length 25us, but the present invention is not limited thereto.

[0121] ●Category 3: LBT that uses a fixed-size CW to perform random backoff

[0122] - The Tx entity obtains a random number within a fixed-size CW and sets it as the initial value of the backoff counter (or backoff timer) N, and performs backoff using the set backoff counter N. In other words, in the backoff procedure, the Tx entity decrements the backoff counter by 1 each time the channel is sensed to be idle during a predetermined slot period. Here, the predetermined slot period may be 9us, but the present invention is not limited to this. The backoff counter N is decremented by 1 from its initial value, and when the value of the backoff counter N reaches 0, the Tx entity performs transmission. On the other hand, in order to perform backoff, the Tx entity first senses whether the channel is idle during the second interval (i.e., the differ period Td). According to an embodiment of the present invention, the Tx entity senses (or determines) whether the channel is idle during the second interval depending on whether the channel is idle during at least a portion of the second interval (e.g., one slot period). The second interval is set based on the channel access priority class of the Tx entity and consists of a period of 16us followed by m consecutive slot periods, where m is the value set by the channel access priority class. If the Tx entity senses that the channel is idle during the second interval, it performs channel sensing to decrement the backoff counter. On the other hand, if the channel is sensed to be occupied during the backoff procedure, the backoff procedure is interrupted. After the backoff procedure is interrupted, the Tx entity resumes backoff if the channel is sensed to be idle during an additional second interval. In this way, the Tx entity transmits if the channel is idle for the second interval plus the slot periods of the backoff counter N. In this case, the initial value of the backoff counter N is obtained within a fixed-size CW.

[0123] ●Category 4: LBT that uses variable-size CW to perform random backoff

[0124] - The Tx entity acquires a random number within a variable-size CW and sets it as the initial value of the backoff counter (or backoff timer) N, and then uses the set backoff counter N to perform backoff. More specifically, the Tx entity adjusts the size of the CW based on HARQ-ACK information for previous transmissions, but the initial value of the backoff counter N is acquired within the adjusted-size CW. The detailed process by which the Tx entity performs backoff is as described in Category 3. The Tx entity transmits if the channel is idle for the second interval plus the slot period of the backoff counter N. In this case, the initial value of the backoff counter N is acquired within a variable-size CW.

[0125] In categories 1 to 4, the Tx entity is a base station or a terminal. In embodiments of the present invention, the first type of channel access refers to a category 4 channel access, and the second type of channel access refers to a category 2 channel access.

[0126] Figure 16 shows the channel access process based on Category 4 LBT according to an embodiment of the present invention.

[0127] To access the channel, first, the Tx entity performs channel sensing for the differ period Td in S302. According to an embodiment of the present invention, the differ period T in S302 d Channel sensing for the channel is performed via channel sensing during at least a portion of the defer period Td. For example, during the defer period T d Channel sensing for the aforementioned defer period T d This is done via channel sensing during one slot period within the system. x The entity checks if the channel is idle via channel sensing for the differ period Td in S304. d If it is sensed to be in an idle state, T xThe entity proceeds to S306. If the channel is sensed as idle for the defer period T d (i.e., if it is sensed as occupied), the entity returns to S302. T x If the channel is sensed as idle for the defer period T x the entity repeats the process from S302 to S304 until the channel is sensed as idle for the defer period T d . The defer period T d is set based on the channel access priority class of the Tx entity and is composed of a period of 16 us and m consecutive slot periods. Here, m is a value set according to the channel access priority class.

[0128] Next, the Tx entity obtains a random number from a predetermined CW and sets it as the initial value of the backoff counter (or backoff timer) N, and proceeds to S306 and S308. The initial value of the backoff counter N is randomly selected from the values between 0 and CW. The Tx entity performs a backoff procedure using the set backoff counter N. That is, the Tx entity repeats the process from S308 to S316 until the value of the backoff counter N reaches zero to perform the backoff procedure. On the other hand, although FIG. 16 shows that S306 is performed after the channel is sensed as idle for the defer period Td, the present invention is not limited to this. That is, S306 may be performed independently of S302 to S304, or may be performed before S302 to S304. When S306 is performed before S302 to S304, if the channel is sensed as idle for the defer period Td by S302 to S304, the Tx entity proceeds to S308.

[0129] In S308, the Tx entity checks if the value of the backoff counter N is 0. If the value of the backoff counter N is 0, the Tx entity proceeds to S320 to perform transmission. If the value of the backoff counter N is not 0, the Tx entity proceeds to S310. In S310, the Tx entity decreases the value of the backoff counter N by 1. According to one embodiment, the Tx entity selectively decreases the value of the backoff counter by 1 during the channel sensing process for each slot. In this case, S10 may be skipped at least once at the Tx entity's discretion. Next, the Tx entity performs channel sensing for an additional slot period in S312. The Tx entity checks in S314 whether the channel is idle through channel sensing for the additional slot period. If the channel is sensed to be idle for the additional slot period, the Tx entity returns to S308. In this way, the Tx entity decreases the backoff counter by 1 each time the channel is sensed to be idle during a predetermined slot period. Here, the preset slot period may be 9us, but the present invention is not limited to this.

[0130] In S314, if the channel is not sensed as idle for the additional slot period (i.e., if it is sensed as occupied), the Tx entity proceeds to S316. In S316, the Tx entity checks whether the channel is idle for the additional differ period Td. According to an embodiment of the present invention, channel sensing in S316 is performed on a slot-by-slot basis. That is, the Tx entity checks whether the channel is sensed as idle for all slot periods of the additional differ period Td. If an occupied slot is detected within the additional differ period Td, the Tx entity immediately restarts S316. If the channel is sensed as idle for all slot periods of the additional differ period Td, the Tx entity returns to S308.

[0131] On the other hand, if the value of the backoff counter N is confirmed to be 0 in S308, the Tx entity performs the transmission in S320. The Tx entity receives HARQ-ACK feedback corresponding to the transmission in S322. The Tx entity confirms the success or failure of the previous transmission via the received HARQ-ACK feedback. Next, the Tx entity adjusts the CW size for the next transmission based on the received HARQ-ACK feedback in S324.

[0132] Thus, after sensing the channel as idle for the defer period Td, the Tx entity transmits if the channel remains idle for N additional slot periods. As mentioned above, the Tx entity may be a base station or a terminal, and the channel access process in Figure 16 is used for downlink transmission at a base station and / or uplink transmission at a terminal.

[0133] The following proposes a method for adaptively adjusting the CWS during channel access in unlicensed bandwidth. The CWS is adjusted based on UE (User Equipment) feedback, and the UE feedback used for CWS adjustment includes HARQ-ACK feedback and CQI / PMI / RI. This invention proposes a method for adaptively adjusting the CWS based on HARQ-ACK feedback. HARQ-ACK feedback includes at least one of ACK, NACK, DTX, and NACK / DTX.

[0134] As mentioned above, in wireless LAN systems, CWS is also adjusted based on ACK. If ACK feedback is received, CWS is reset to its minimum value (CWmin), and if ACK feedback is not received, CWS increases. However, cellular systems require a method of adjusting CWS that takes into account multiple accesses.

[0135] First, in order to explain the present invention, the following terms are defined.

[0136] - A set of HARQ-ACK feedback values ​​(i.e., a HARQ-ACK feedback set): This refers to the HARQ-ACK feedback values ​​used for CWS updates / adjustments. The HARQ-ACK feedback set is decoded at the time the CWS is determined and corresponds to the available HARQ-ACK feedback values. The HARQ-ACK feedback set includes HARQ-ACK feedback values ​​for one or more DL (channel) transmissions (e.g., PDSCH) on an unlicensed bandwidth carrier (e.g., Scell, NR-U cell). The HARQ-ACK feedback set includes HARQ-ACK feedback values ​​for DL ​​(channel) transmissions (e.g., PDSCH), e.g., multiple HARQ-ACK feedback values ​​fed back from multiple terminals. The HARQ-ACK feedback value indicates received response information for a code block group (CBG) or transmission block (TB) and represents one of the following: ACK, NACK, DTX, or NACK / DTX. Depending on the context, the HARQ-ACK feedback value may be used interchangeably with terms such as HARQ-ACK value, HARQ-ACK information bits, and HARQ-ACK response.

[0137] -Reference window: This refers to a time interval in an unlicensed bandwidth carrier (e.g., Scell, NR-U cell) where DL transmissions (e.g., PDSCH) corresponding to a set of HARQ-ACK feedback occur. The reference window is defined by the embodiment on a slot or subframe basis. The reference window refers to one or more specific slots (or subframes). According to embodiments of the present invention, a specific slot (or reference slot) includes the start slot of the most recent DL transmission burst that is expected to be able to utilize at least some of the HARQ-ACK feedback.

[0138] Figure 17 shows an example of a method for adjusting the competition window size (CWS) based on HARQ-ACK feedback. In the example in Figure 17, the Tx entity may be a base station and the Rx entity may be a terminal, but the present invention is not limited to this. Also, the example in Figure 17 assumes a channel access process for DL ​​transmission at a base station, but at least some of the configurations may be applied to a channel access process for UL transmission at a terminal.

[0139] Referring to Figure 17, after the Tx entity has transmitted the nth DL transmission burst on an unlicensed bandwidth carrier (e.g., Scell, NR-U cell) S402, if additional DL transmission is required, it transmits the (n+1)th DL transmission burst based on LBT channel access S412. Here, a transmission burst refers to a transmission through one or more adjacent slots (or subframes). Figure 17 illustrates the channel access procedure and CWS coordination method based on the first type of channel access described above (i.e., Category 4 channel access).

[0140] First, the Tx entity receives HARQ-ACK feedback corresponding to PDSCH transmissions(etc.) on an unlicensed bandwidth carrier (e.g., Scell, NR-U cell) in S404. The HARQ-ACK feedback used for CWS tuning includes HARQ-ACK feedback corresponding to the most recent DL transmission burst (i.e., the nth DL transmission burst) on the unlicensed bandwidth carrier. More specifically, the HARQ-ACK feedback used for CWS tuning includes HARQ-ACK feedback corresponding to PDSCH transmissions on a reference window within the most recent DL transmission burst. The reference window refers to one or more specific slots (or subframes). According to embodiments of the present invention, the specific slots (or reference slots) include the starting slot of the most recent DL transmission burst from which at least some HARQ-ACK feedback is expected to be available.

[0141] When HARQ-ACK feedback is received, a HARQ-ACK value is obtained for each transmission block TB. The HARQ-ACK feedback includes at least one of the TB-based HARQ-ACK bit sequence and the CBG-based HARQ-ACK. If the HARQ-ACK feedback is a TB-based HARQ-ACK bit sequence, one HARQ-ACK information bit is obtained per TB. On the other hand, if the HARQ-ACK feedback is a CBG-based HARQ-ACK bit sequence, N HARQ-ACK information bits (etc.) are obtained per TB. Here, N is the maximum number of CBGs per TB configured in the Rx entity of the PDSCH transmission. According to an embodiment of the present invention, the HARQ-ACK value (etc.) for each TB is determined by the HARQ-ACK information bits (etc.) of the HARQ-ACK feedback for each TB in order to determine the CWS. More specifically, if the HARQ-ACK feedback is a TB-based HARQ-ACK bit sequence, one HARQ-ACK information bit of the corresponding TB is determined as the HARQ-ACK value. However, if the HARQ-ACK feedback is a CBG-based HARQ-ACK bit sequence, one HARQ-ACK value is determined based on N HARQ-ACK information bits (etc.) corresponding to the CBG contained in the corresponding TB.

[0142] Next, the Tx entity adjusts the CWS based on the HARQ-ACK value determined in S404 in S406. In other words, the Tx entity determines the CWS based on the HARQ-ACK value(s) determined by the HARQ-ACK information bits(s) for each TB in the HARQ-ACK feedback. More specifically, the CWS is adjusted based on the proportion of NACKs in the HARQ-ACK value(s). First, the variables are defined as follows:

[0143] -p: Priority class value -CW_min_p: Pre-configured minimum CWS value for priority class p -CW_max_p: Pre-configured maximum CWS value for priority class p -CW_p: CWS for transmitting priority class p. CW_p is set to one of several CWS values ​​between CW_min_p and CW_max_p that are included in the allowed CWS set for priority class p.

[0144] According to an embodiment of the present invention, the CWS is determined by the following steps.

[0145] Step A-1) First, for priority class p, CW_p is set to CW_min_p. In this case, priority class p includes {1, 2, 3, 4}.

[0146] Step A-2) If the proportion of NACKs among the HARQ-ACK values ​​for PDSCH transmissions (and) in the reference window k is Z% or greater, then CW_p is increased to the next highest tolerance for all priority classes p (and the process remains in Step A-2). Otherwise, the process proceeds to Step A-1. Here, Z is a preset integer in the range 0 ≤ Z ≤ 100, and according to one embodiment, it is set to one of {30, 50, 70, 80, 100}.

[0147] Here, the reference window k includes the most recent transmission start slot (or subframe) by the Tx entity. The reference window k is also the slot (or subframe) where at least some HARQ-ACK feedback is expected to be possible. If CW_p = CW_max_p, then the next highest tolerance for adjusting CW_p is CW_max_p.

[0148] Next, the Tx entity selects a random number from within the CWS determined in S406 and sets it as the initial value of the backoff counter N in S408. The Tx entity then performs a backoff using the set backoff counter N in S410. In other words, the Tx entity decrements the backoff counter by 1 for each slot period during which the channel is sensed to be idle. When the value of the backoff counter reaches 0, the Tx entity transmits the (n+1)th DL transmission burst on that channel in S412.

[0149] On the other hand, in the CWS adjustment process described above, it should be determined whether or not DTX or NACK / DTX are considered together in addition to ACK and NACK in the HARQ-ACK feedback. According to an embodiment of the present invention, whether or not DTX or NACK / DTX are considered together in the CWS adjustment process is determined by whether the transmission in the unlicensed band is based on self-carrier scheduling or cross-carrier scheduling.

[0150] During self-carrier scheduling, DL transmissions (e.g., PDSCH) on an unlicensed bandwidth carrier are scheduled via a control channel (e.g., (E)PDCCH) transmitted on the same unlicensed bandwidth carrier. Here, DTX occurs when DL transmission fails on an unlicensed bandwidth carrier due to a hidden node or the like, and is used together with NACK for CWS adjustment. DTX is also one way for a terminal to notify a base station if it was unable to decode a control channel (e.g., (E)PDCCH) containing scheduling information, even though the base station transmitted it to the terminal. DTX is determined either solely by the HARQ-ACK feedback value or by considering the HARQ-ACK feedback value and the actual scheduling status. According to an embodiment of the present invention, in a self-carrier scheduling situation, DTX and NACK / DTX are counted by NACK to adjust the CWS. That is, if the sum of NACK, DTX, and NACK / DTX among the HARQ-ACK values ​​for PDSCH transmissions (etc.) in the reference window k is Z% or greater, the CWS is increased to the next highest tolerance value. Otherwise, CWS will be reset to its minimum value.

[0151] During cross-carrier scheduling, DL transmissions on unlicensed band carriers (e.g., PDSCH) are scheduled via control channels (e.g., (E)PDCCH) transmitted on licensed band carriers. In this case, DTX feedback is used to determine the terminal's decoding status for the control channel transmitted on the licensed band carrier, and is therefore not useful for adaptively adjusting the CWS for channel access in the unlicensed band. Thus, according to embodiments of the present invention, DTX may be ignored to determine the CWS in cross-carrier scheduling situations from licensed bands. That is, to adjust the CWS, the proportion of NACK may be calculated by considering only ACK and NACK among the HARQ-ACK values, or the proportion of NACK may be calculated by considering only ACK, NACK, and NACK / DTX. Thus, when calculating the proportion of NACK, DTX is excluded.

[0152] Figure 18 is a block diagram showing the configuration of a terminal and a base station according to one embodiment of the present invention. In one embodiment of the present invention, the terminal is embodied in various types of wireless communication devices or computing devices that ensure portability and mobility. The terminal is referred to as UE, STA (Station), MS (Mobile Subscriber), etc. In the embodiment of the present invention, the base station controls and manages the cells (e.g., macrocells, femtocells, picocells, etc.) in the service area and performs functions such as signal transmission, channel assignment, channel monitoring, self-diagnosis, and relaying. The base station is referred to as gNB (next Generation NodeB) or AP (Access Point), etc.

[0153] As shown in the figure, a terminal 100 according to one embodiment of the present invention includes a processor 110, a communication module 120, a memory 130, a user interface unit 140, and a display unit 150.

[0154] First, the processor 110 executes various instructions or programs to process data inside the terminal 100. The processor 100 also controls the overall operation of the terminal 100, including each unit, and controls the transmission and reception of data between units. Here, the processor 110 is configured to perform the operations described in the embodiment of the present invention. For example, the processor 110 may receive slot configuration information, determine the slot configuration based on that information, and perform communication according to the determined slot configuration.

[0155] Next, the communication module 120 is an integrated module that performs wireless communication using a wireless communication network and wireless LAN access using a wireless LAN. To this end, the communication module 120 incorporates multiple network interface cards (NICs), such as cellular communication interface cards 121 and 122 and an unlicensed band communication interface card 123, either internally or externally. In the drawing, the communication module 120 is shown as an integrated module, but each network interface card may be arranged independently depending on the circuit configuration or application, contrary to the drawing.

[0156] The cellular communication interface card 121 transmits and receives radio signals to and from at least one of the base station 200, an external device, and a server via a mobile communication network, and provides cellular communication services in a first frequency band based on instructions from the processor 110. According to one embodiment, the cellular communication interface card 121 includes at least one NIC module that utilizes a frequency band of less than 6 GHz. At least one NIC module of the cellular communication interface card 121 independently performs cellular communication with at least one of the base station 200, an external device, and a server, depending on the cellular communication standard or protocol of the sub-6 GHz frequency band supported by the NIC module.

[0157] The cellular communication interface card 122 uses a mobile communication network to send and receive radio signals with at least one of the base station 200, an external device, or a server, and provides cellular communication services in the second frequency band based on instructions from the processor 110. In one embodiment, the cellular communication interface card 122 includes at least one NIC module that utilizes a frequency band of 6 GHz or higher. At least one NIC module of the cellular communication interface card 122 independently performs cellular communication with at least one of the base station 200, an external device, or a server, according to the cellular communication standard or protocol of the 6 GHz or higher frequency band supported by the NIC module.

[0158] The unlicensed band communication interface card 123 transmits and receives radio signals to and from at least one of the base station 200, an external device, or a server via the third frequency band, which is an unlicensed band, and provides communication services in the unlicensed band based on instructions from the processor 110. The unlicensed band communication interface card 123 includes at least one NIC module that utilizes the unlicensed band. For example, the unlicensed band may be a band of 2.4GHz, 5GHz, 6GHz, 7GHz, or 52.6GHz or higher. At least one NIC module of the unlicensed band communication interface card 123 independently or dependently performs cellular communication with at least one of the base station 200, an external device, or a server, depending on the unlicensed band communication standard or protocol of the frequency band supported by the NIC module.

[0159] Next, the memory 130 stores control programs used by the terminal 100 and various data associated with them. Such control programs include predetermined programs necessary for the terminal 100 to communicate wirelessly with at least one of the following: a base station 200, an external device, or a server.

[0160] Next, the user interface 140 includes various forms of input / output means provided in the terminal 100. In other words, the user interface unit 140 receives user input using various input means, and the processor 110 controls the terminal 100 based on the received user input. The user interface 140 also outputs based on instructions from the processor 110 using various output means.

[0161] Next, the display unit 150 outputs various images to the display screen. The display unit 150 outputs various display objects, such as content generated by the processor 110 or user interfaces based on control instructions from the processor 110.

[0162] Furthermore, the base station 200 according to the embodiment of the present invention includes a processor 210, a communication module 220, and a memory 230.

[0163] First, the processor 210 executes various instructions or programs to process data within the base station 200. The processor 210 also controls the overall operation of the base station 200, including each unit, and controls the transmission and reception of data between units. Here, the processor 210 is configured to perform the operations described in the embodiment of the present invention. For example, the processor 210 may signal slot configuration information and perform communication according to the signaled slot configuration.

[0164] Next, the communication module 220 is an integrated module that performs wireless communication using a wireless communication network and wireless LAN access using a wireless LAN. To this end, the communication module 220 incorporates multiple network interface cards, such as cellular communication interface cards 221 and 222, and an unlicensed band communication interface card 223, either internally or externally. In the drawings, the communication module 220 is shown as an integrated module, but each network interface card may be arranged independently depending on the circuit configuration or application, contrary to the drawings.

[0165] The cellular communication interface card 221 transmits and receives wireless signals to and from at least one of the terminal 100, external devices, and servers described above using a mobile communication network, and provides cellular communication services in the first frequency band based on instructions from the processor 210. According to one embodiment, the cellular communication interface card 221 includes at least one NIC module that utilizes a frequency band of less than 6 GHz. At least one NIC module of the cellular communication interface card 221 independently performs cellular communication with at least one of the terminal 100, external devices, and servers, according to the cellular communication standard or protocol of the frequency band of less than 6 GHz supported by the NIC module.

[0166] The cellular communication interface card 222 uses a mobile communication network to send and receive wireless signals to and from at least one of the terminal 100, an external device, and a server, and provides cellular communication services in the second frequency band based on instructions from the processor 210. In one embodiment, the cellular communication interface card 222 includes at least one NIC module that utilizes a frequency band of 6 GHz or higher. At least one NIC module of the cellular communication interface card 222 independently performs cellular communication with at least one of the terminal 100, an external device, and a server, according to the cellular communication standard or protocol of the 6 GHz or higher frequency band supported by the NIC module.

[0167] The unlicensed band communication interface card 223 uses the third frequency band, which is an unlicensed band, to send and receive wireless signals with at least one of the terminal 100, an external device, or a server, and provides communication services in the unlicensed band based on instructions from the processor 210. The unlicensed band communication interface card 223 includes at least one NIC module that utilizes the unlicensed band. For example, the unlicensed band may be 2.4GHz, 5GHz, 6GHz, 7GHz, or a band of 52.6GHz or higher. At least one NIC module of the unlicensed band communication interface card 223 independently or dependently performs cellular communication with at least one of the terminal 100, an external device, or a server, depending on the unlicensed band communication standard or protocol of the frequency band supported by the NIC module.

[0168] The terminal 100 and base station 200 shown in Figure 18 are block diagrams according to one embodiment of the present invention, and the separately shown blocks represent logically distinguished elements of the device. Therefore, the above-mentioned elements of the device are mounted on one or more chips depending on the device design. Furthermore, some components of the terminal 100, such as the user interface unit 150 and the display unit 150, may be selectively provided in the terminal 100. In addition, the user interface 140 and the display unit 150 may be additionally provided in the base station 200 as needed.

[0169] Figure 19 is a flowchart illustrating one embodiment of the present invention and an example of a method for transmitting uplink data in an unlicensed bandwidth.

[0170] Referring to Figure 19, the terminal performs channel sensing with an activated BWP in order to transmit PUSCH (Physical Uplink Shared Channel) in the unlicensed band. If the sensed channel is idle, it transmits PUSCH to the base station on the idle channel.

[0171] Specifically, the terminal receives an RRC (Radio Resource Control Configuration) from the base station, which includes information for receiving downlink control information and information for PUSCH transmission (S19010).

[0172] The terminal can receive Downlink Control Information (DCI) based on the information contained in the received RRC settings (S19020).

[0173] DCI may include resource allocation information related to resources allocated for PUSCH transmission, configuration information related to reference signals, and so on.

[0174] Furthermore, if multiple BWPs exist, the DCI may include an indicator that shows which BWP was activated for the terminal to transmit a PUSCH, and information related to the subband where LBT operation for channel sensing, as described in Figure 15, is performed when transmitting uplink data in the unlicensed band.

[0175] In this case, subbands may be assigned consecutively, and information related to consecutively assigned subbands may be included in the DCI using the RIV (Resource Information Value) method.

[0176] Furthermore, the Resource Blocks (RPBs) included in an activated BWP may be included in the BWP in an interlaced structure mapped at regular intervals, and resource allocation information related to the allocated resources (RPBs) may be included in the DCI in RIV or bitmap format.

[0177] The RIV method refers to a method of making the terminal recognize the allocated resource by including the starting index and length information of the allocated resource in the DCI and informing the terminal of this information. The bitmap method refers to a method of indicating the specific location of the allocated resource using each bit.

[0178] The method for including information related to subbands and allocated resources in the DCI is explained in detail in Figures 20-22 below.

[0179] Subsequently, the terminal performs channel sensing to determine whether the assigned subband is idle or not (S19030). If the assigned subband is not idle, the terminal can sense the subband again using the method described in Figure 15. On the other hand, if the assigned subband is idle, the terminal can send a PUSCH to the base station using the PRB included in the assigned subband (S19040).

[0180] Figure 20 shows an example of a resource structure for transmission on a PUSCH (Physical Uplink Shared Channel), which is one embodiment of the present invention.

[0181] Referring to Figure 20, among the one or more BWPs assigned to a terminal, there may be candidate LBT subbands for uplink push transmission on an activated BWP that has multiple LBT subbands.

[0182] Specifically, four methods may be considered for channel connection on the uplink to perform BWP-based operation within a single carrier for NR-U, as follows:

[0183] First, the base station configures one or more multiple BWPs for uplink transmission to the terminal and activates at least one of them. If the terminal successfully accesses the uplink channel with one or more of the at least one BWP, it can transmit a PUSCH with the one or more BWPs that have successfully accessed the channel.

[0184] At this time, the base station may implicitly or explicitly signal the terminal to provide information about one or more activated BWPs that the base station intends to use for uplink transmission at the terminal.

[0185] This prevents unnecessary channel access from occurring on one or more activated BWPs that are not intended for transmission by the terminal. In other words, the base station can inform the terminal, either implicitly or explicitly, of information regarding one or more activated BWPs that are intended for uplink transmission, out of at least one activated BWP.

[0186] For example, a terminal can implicitly or explicitly receive information about an activated BWP performing uplink transmission via DCI transmitted from a base station, and can recognize the activated BWP performing uplink transmission.

[0187] The base station can use implicit or explicit signaling to inform the terminal of at least one BWP on which uplink transmission will occur, thereby preventing the terminal from making unnecessary channel connections on activated BWPs that are not allocated for uplink transmission.

[0188] Furthermore, the base station can explicitly or implicitly inform the terminal of the presence or absence of uplink scheduling in the LBT subband unit included in the activated BWP for the terminal's uplink transmission. For example, the presence or absence of uplink scheduling may be included in the DCI in the LBT subband unit and transmitted to the terminal.

[0189] Therefore, even if a single activated BWP contains multiple LBT subbands, the terminal can only access the channel on at least one of the multiple LBT subbands that is scheduled and allocated for PUSCH transmission.

[0190] The terminal can decide whether or not to send a PUSCH message depending on whether or not it has successfully accessed the channel.

[0191] A base station may include and transmit information about one or more activated BWPs in a UL grant to explicitly communicate to a terminal, and may include and transmit information about an LBT subband scheduled and allocated for PUSCH transmission within one activated BWP to a terminal by explicit signaling.

[0192] In other words, the base station can transmit to the terminal, using an indicator, the BWP activated for uplink transmission, and the LBT subband within the BWP that is scheduled and allocated for uplink transmission.

[0193] For example, a BWP activated for a terminal's push transmission and an LBT subband allocated by scheduling for a push transmission may be indicated to the terminal by an indicator included in the DCI.

[0194] Furthermore, the BWP activated for push transmission and the LBT subbands allocated by scheduling for push transmission can be instructed to the terminal using a bitmap method, or the base station can instruct the terminal on each case in which LBT subbands are allocated, as shown in Figure 20, so that LBT subbands can be allocated consecutively. For example, the base station can send an indicator to the terminal that includes the start index and length of the consecutively allocated subbands, and the terminal can recognize the consecutively allocated LBT subbands based on the start index and length of the subbands included in the indicator sent from the base station. If the terminal performs an LBT operation on the recognized subband and successfully accesses the channel, it can perform a push transmission.

[0195] Secondly, the base station configures one or more multiple BWPs for uplink transmission to the terminal and activates some or all of them. If the terminal successfully accesses the uplink channel with at least one of the activated BWPs, it can transmit a PUSCH message with one of the BWPs that successfully accessed the channel.

[0196] In this case, the base station can implicitly or explicitly signal the terminal about one or more activated BWPs that the base station intends to use for uplink transmission at the terminal. This prevents the terminal from unnecessarily accessing the channel with one or more activated BWPs that it does not intend to use for transmission. In other words, the base station can implicitly or explicitly signal the terminal about one activated BWP that it intends to use for uplink transmission from among at least one activated BWP.

[0197] For example, a terminal can implicitly or explicitly receive information about an activated BWP performing uplink transmission via DCI transmitted from a base station, and can recognize the activated BWP performing uplink transmission.

[0198] By using implicit or explicit signaling, the base station can inform the terminal of a single BWP on which uplink transmission will be performed, thereby preventing the terminal from performing unnecessary actions such as establishing a channel connection on an activated BWP that is not assigned for uplink transmission.

[0199] Furthermore, the base station can explicitly or implicitly inform the terminal of the presence or absence of uplink scheduling in units of LBT subbands included in the activated BWP for the terminal's uplink transmission. For example, the presence or absence of uplink scheduling in units of LBT subbands may be included in the DCI and transmitted to the terminal.

[0200] Therefore, even if a single activated BWP contains multiple LBT subbands, the terminal can only access the channel on at least one of the multiple LBT subbands that is scheduled and allocated for PUSCH transmission.

[0201] The terminal can decide whether or not to send a PUSCH message depending on whether or not it has successfully accessed the channel.

[0202] A base station can use a UL grant to explicitly transmit information about one or more activated BWPs to a terminal. A base station can use a UL grant to transmit information about an LBT subband scheduled and allocated for PUSCH transmission within one activated BWP to a terminal via explicit signaling.

[0203] In other words, the base station can transmit to the terminal, in an indication, the BWP activated for uplink transmission, and the LBT subband within the BWP that is scheduled and allocated for uplink transmission.

[0204] For example, the BWP activated for a terminal's push transmission, and the LBT subband allocated by scheduling for push transmission, may be indicated to the terminal by an indicator included in the DCI.

[0205] Furthermore, the BWP activated for push transmission and the LBT subbands allocated by scheduling for push transmission can be instructed to the terminal using a bitmap method, or the base station can instruct the terminal in each case where LBT subbands are allocated so that LBT subbands can be allocated consecutively, as shown in Figure 20. For example, the base station can send an indicator to the terminal that includes the start index and length of the consecutively allocated subbands, and the terminal can recognize the consecutively allocated LBT subbands based on the start index and length of the subbands included in the indicator sent from the base station. If the terminal performs an LBT operation on the recognized subband and successfully accesses the channel, it can perform an uplink transmission.

[0206] Thirdly, the base station configures one or more multiple BWPs for uplink transmission to the terminal and activates one of them. If the terminal successfully accesses the channel across one or more LBT subbands configured and included in the activated BWP, it can send a PUSCH to the base station using that BWP.

[0207] In this case, the base station can implicitly or explicitly signal to the terminal information about the activated BWP that the base station intends the terminal to use for uplink transmission. The base station can also explicitly or implicitly inform the terminal whether or not uplink scheduling is available for each LBT subband included in the activated BWP for the terminal's uplink transmission. Therefore, a method may be used in which the terminal establishes a channel connection only in the LBT subband that is scheduled and allocated for PUSCH transmission from among the multiple LBT subbands included in a single activated BWP, and whether or not to transmit to PUSCH depends on the success or failure of the channel connection in one or more LBT subbands allocated to each terminal within the BWP.

[0208] A base station can include information about an activated BWP in a UL grant and send it to a terminal in order to explicitly communicate information about a single activated BWP to the terminal, and can also include information about an LBT subband scheduled and allocated for PUSCH transmission within a single activated BWP in a UL grant to explicitly signal to the terminal.

[0209] In other words, the base station can transmit to the terminal, via an indicator, the BWP activated for uplink transmission and the LBT subband within the BWP that is scheduled and allocated for uplink transmission.

[0210] For example, the BWP activated for a terminal's push transmission and the LBT subband allocated by scheduling for push transmission may be indicated to the terminal by an indicator included in the DCI.

[0211] Furthermore, the BWP activated for push transmission and the LBT subbands allocated by scheduling for push transmission can be instructed to the terminal in a bitmap manner, or the base station can instruct the terminal in each case in which the LBT subbands are allocated so that the LBT subbands can be allocated consecutively, as shown in Figure 20 below. For example, the base station can send an indicator to the terminal that includes the start index and length of the consecutively allocated LBT subbands, and the terminal can recognize the consecutively allocated LBT subbands based on the start index and length of the LBT subbands included in the indicator sent from the base station. If the terminal performs an LBT operation on the recognized LBT subband and successfully accesses the channel, it can perform an uplink transmission.

[0212] - If a single BWP has a bandwidth (BW) greater than 20 MHz, which is the basic unit in which LBT operation is performed, the success or failure of channel connection in an activated BWP may be determined based on the BWP configuration and the success or failure of CCA in the LBT subband.

[0213] Specifically, if a BWP consists of one or more LBT subbands, and the CCA in one or more LBT subbands allocated for PUSCH transmission by a UL grant is successful, then it can be determined that the CCA in the BWP for PUSCH transmission has been successful, and the terminal can perform PUSCH transmission on the LBT subbands included in the BWP that have successfully undergone CCA.

[0214] However, if a successful CCA in the BWP is only determined when CCA is successful in all LBT subbands, then even if channel connection is successful in some LBT subbands and the channels are idle, if CCA fails in the remaining LBT subbands and channel connection fails, it may be impossible to perform push transmission on the activated BWP.

[0215] In other words, even if channel access is successful in a portion of one or more LBT subbands allocated from the base station to the terminal by UL grant for push transmission within an activated BWP, and the channel is idle, if channel connection fails in the remaining LBT subbands included in the activated BWP, push transmission may become impossible within the entire activated BWP. In this case, the uplink spectral efficiency decreases, the bandwidth size per frequency unit of the BWP increases further, and if multiple LBT subbands are allocated for push transmission, multiple successful channel accesses in 20MHz units of LBT subbands are required, which reduces the probability of successful channel access in the activated BWP and thus the probability of transmission in the activated BWP.

[0216] However, if there is no other mechanism for determining (or recognizing) which of the LBT subbands allocated by the base station to the terminal for push transmission has successfully established an uplink channel connection, then it is possible to determine (or recognize) whether the terminal has succeeded in using LBT for push transmission by performing detection in the LBT subband corresponding to the resource allocated by the base station to the terminal for push transmission.

[0217] However, the base station cannot determine or recognize whether a PUSCH transmission was made after a successful LBT at the terminal, or whether there is a DTX (Decorative Text) that the terminal failed to transmit due to a LBT failure. Therefore, when a terminal transmits a PUSCH, the base station can detect the front-loaded Uplink Dedicated Demodulation Reference Signal (UL DMRS) on an LBT subband basis, thereby recognizing (or determining) which LBT subband the terminal successfully connected to for PUSCH transmission. At the same time, the base station can determine whether the transmission was made after a successful LBT at the terminal, or whether there is a DTX that the terminal failed to transmit due to a LBT failure.

[0218] - Furthermore, when UL transmission is performed by a configured grant, the base station cannot send an indicator to the terminal to direct the LBT subband within the BWP using the UL grant. Therefore, in this case, if the terminal successfully establishes an uplink channel connection on any of the LBT subbands in the activated BWP configured for the terminal on the time resources set by the RRC, the system may be configured to perform UL transmission by the configured grant on that LBT subband.

[0219] However, in the case of UL transmission using a configured grant, frequency resources must be configured on an LBT subband basis in order for transmission to occur on an LBT subband basis, and channel connection must be successful in at least one LBT subband of one or more LBT subbands included in a single activated BWP.

[0220] In this case, if channel connection is successful only in the LBT subband to which UL transmission by UL grant is assigned, UL transmission by UL grant may be prioritized, and UL transmission by configured grant may not occur. In time domain resources configured to transmit configured grants, the base station can perform front-loading UL DMRS detection in LBT subbands where UL transmission by UL grant is not assigned within the activated BWP, in addition to detection in the LBT subband to which UL transmission by UL grant is assigned, to determine whether or not configured grant transmission is occurring.

[0221] Fourth, the base station configures one or more multiple BWPs for uplink transmission to the terminal and activates one of them. If the terminal successfully establishes a channel connection in whole or in part of the LBT subband configured and included in the activated BWP, it can send a PUSCH to the base station using that BWP.

[0222] In this case, the base station can implicitly or explicitly signal to the terminal information about the activated BWP that the base station intends to use for uplink transmission at the terminal. The base station can also explicitly or implicitly inform the terminal whether or not uplink scheduling is available for each LBT subband included in the BWP activated for the terminal's uplink transmission. Therefore, a method may be used in which the terminal establishes a channel connection only in the LBT subband that is scheduled and allocated for PUSCH transmission from among multiple LBT subbands included in a single activated BWP, and whether or not to transmit to PUSCH depends on the success or failure of the channel connection in one or more LBT subbands allocated to each terminal within the BWP.

[0223] A base station may include in its UL grant information to explicitly communicate to a terminal information about one activated BWP, and may also include in its UL grant information about a subband of LBT scheduled and allocated for PUSCH transmission within one activated BWP to transmit to a terminal using explicit signaling.

[0224] In other words, the base station can transmit to the terminal, in an indicator, the BWP activated for uplink transmission, and the subbands within the BWP that are scheduled and allocated for uplink transmission.

[0225] For example, a BWP activated for a terminal's push transmission, and a subband of LBT allocated by scheduling for push transmission, may be indicated to the terminal by an indicator included in the DCI.

[0226] Furthermore, the BWP activated for push transmission and the LBT subbands allocated by scheduling for push transmission can be instructed to the terminal in a bitmap manner, or the base station can instruct the terminal in each case where the LBT subbands are allocated so that the LBT subbands can be allocated consecutively, as shown in Figure 20 below. For example, the base station can send the terminal an indicator containing the start index and length of the consecutively allocated LBT subbands, and the terminal can recognize the consecutively allocated LBT subbands based on the start index and length of the subbands included in the indicator sent from the base station. If the terminal performs an LBT operation on the recognized LBT subband and successfully accesses the channel, it can perform an uplink transmission.

[0227] If a single BWP has a bandwidth (BW) greater than 20 MHz, which is the basic unit in which LBT operation is performed, the success or failure of channel connection in an activated BWP may be determined based on the BWP configuration and the success or failure of CCA in the LBT subband.

[0228] Specifically, if the BWP is composed of one or more LBT sub-bands and CCA in all or only part of the one or more LBT sub-bands allocated for PUSCH transmission by the UL grant is successful, it may be determined that CCA in the BWP for PUSCH transmission is successful, and the terminal can perform PUSCH transmission in the LBT sub-bands included in the BWP where CCA is successful.

[0229] Also, among the activated BWPs, if channel connection is successful in units of some of the one or more LBT sub-bands allocated for PUSCH transmission from the base station to the terminal by the UL grant and the channel is in an idle state, PUSCH transmission may be performed in the allocated some LBT sub-bands where channel connection is successful for PUSCH transmission.

[0230] However, among the LBT sub-bands allocated by the base station for PUSCH transmission, the terminal may fail in channel connection and PUSCH transmission may not be possible in some LBT sub-bands. Therefore, the base station sets the allocation of resources for PUSCH transmission to be allocatable in units of LBT sub-bands, and even if PUSCH transmission is possible only from the terminal in some LBT sub-bands and PUSCH is transmitted only in some LBT sub-bands, the base station can receive the PUSCH transmitted in the LBT sub-bands.

[0231] However, if the base station does not separately have a mechanism to determine whether any of the LBT sub-bands of the LBT sub-bands allocated for PUSCH transmission to the terminal has succeeded in the uplink channel connection, the base station can determine the success or failure of LBT for PUSCH transmission in the terminal by only performing detection in the LBT sub-bands corresponding to the resources allocated for PUSCH transmission to the terminal.

[0232] At this time, whether PUSCH transmission is performed after LBT success at the terminal or DTX occurs when the terminal fails in LBT and cannot transmit PUSCH cannot be determined or recognized by the base station. Therefore, when the base station receives PUSCH from the terminal, it senses the front-loading UL DMRS in units of LBT sub-bands, so that it can recognize (or determine) the LBT sub-bands in which the terminal has successfully connected to the channel among the LBT sub-bands assigned for PUSCH transmission. At the same time, it can determine whether PUSCH transmission was performed after LBT success at the terminal or DTX occurred when the terminal failed in LBT and could not transmit PUSCH.

[0233] Also, when UL transmission is performed by a configured grant, the base station cannot transmit an indicator for instructing the terminal to use the UL grant to perform LBT in the BWP. Therefore, in this case, if the terminal successfully connects to the uplink channel in any of the LBT sub-bands in the activated BWP set for the terminal on the time resource set by RRC, UL transmission by the configured grant may be set to be performed in that LBT sub-band.

[0234] However, in the case of UL transmission by a configured grant, in order to perform transmission in units of LBT sub-bands, it is necessary to set frequency resources in units of LBT sub-bands, and it is necessary to successfully connect to the channel in at least one of the one or more LBT sub-bands included in one activated BWP.

[0235] In this case, if channel connection is successful only in the LBT subband to which UL transmission by UL grant is assigned, UL transmission by UL grant may be prioritized, and UL transmission by configured grant may not occur. In time domain resources configured to transmit configured grants, the base station can perform front-loading UL DMRS detection in LBT subbands where UL transmission by UL grant is not assigned within the activated BWP, in addition to detection in the LBT subband to which UL transmission by UL grant is assigned, to determine whether or not configured grant transmission is occurring.

[0236] <Resource allocation method when a single BWP is configured to have one or more LBT subbands>

[0237] Figure 21 shows an example of an interlace structure for allocating uplink resources in LTE-LAA.

[0238] Referring to Figure 21, during NR-U operation, a single BWP may consist of one or more LBT subbands (sub-bands, or LBT units) in order to perform LBT operation for channel connection.

[0239] Specifically, in uplink transmission, in order to use unlicensed bandwidth, the OCBB (occupied channel bandwidth) requirements specified and required for that unlicensed bandwidth must be met.

[0240] For example, in the case of uplink transmission, there is a condition that 80% of the nominal channel bandwidth must be met. To meet this, LTE-LAA may be configured to spread across the entire bandwidth so that it has equivalent PRB spacing, as shown in Figure 21.

[0241] For example, in the system bandwidth, each PRB may have 10 different interlaced indices set using a 10-interlaced structure with 10 intervals, and each assigned index may be configured to be allocated to the channel bandwidth overall.

[0242] Such a PRB structure can be called an interlaced structure, and in NR-U operation that uses unlicensed bandwidth based on NR, such an interlaced structure may be used to satisfy the OCB requirements.

[0243] Therefore, failure to meet these requirements may make it impossible to transmit uplink or downlink data using unlicensed bandwidth.

[0244] Therefore, the present invention proposes a method for transmitting and receiving data using unlicensed bandwidth while satisfying OCB requirements based on NR.

[0245] In other words, in NR-U-based operation that transmits and receives uplink or downlink data using unlicensed bandwidth based on NR, we propose a resource allocation method for transmitting uplink data when a single BWP consists of one or more LBT subbands (or LBT units).

[0246] Figure 22 shows an example of a candidate LBT subband for uplink push transmission and an interlacing structure for it on an activated Bandwidth Part (BWP) having multiple LBT (Listen Before Talk) subbands among one or more Bandwidth Parts (BWPs).

[0247] Referring to Figure 22, the base station can allocate LBT subbands and PRBs included in the activated BWP at regular intervals in order to use the unlicensed band while satisfying the OCB requirement for the unlicensed band, and can inform the terminal of the location of the allocated LBT subbands and PRBs.

[0248] Specifically, as shown in Figure 20, the sizes of BWPs configured for each terminal may differ from one another, and the PRBs assigned to each terminal may be assigned within BWPs that are activated at regular intervals.

[0249] For example, as shown in Figure 22, let N be the number of LBT subbands included in one BWP, and let M be defined as the interval between individual RBs in the frequency domain within an interlaced structure within the LBT subband. In this case, the M value may be the same for different subcarrier spacing (SCS) values, or it may differ depending on the SCS value. For example, if 15kHz and 30kHz are used as different SCS values, an M value of 10 or 11 may be used for 15kHz, and an M value of 5 may be used for 30kHz.

[0250] First, in the case of transmitting uplink data, the terminal can receive resource allocation information for frequency resources for transmitting uplink data from the base station. In this case, the base station can allocate uplink frequency resources to the terminal and allocate resources for uplink transmission using an interlaced structure only on the continuously allocated LBT subbands. Alternatively, the base station can allocate resources for uplink transmission to the terminal on the allocated LBT subbands, using the interlaced structure within each LBT subband, regardless of whether the LBT subbands are allocated continuously or discontinuously.

[0251] For NR-U operation, one BWP is composed of one or more LBT sub-bands. When the terminal performs uplink transmission, due to the scheduling flexibility of the base station and the LBT failure for channel connection in a specific LBT sub-band of the terminal, both the allocation method of discontinuous LBT sub-bands and the allocation method of continuous LBT sub-bands may be used. In this case, the base station can notify the terminal of the allocation information of discontinuous LBT sub-bands or the allocation information of continuous LBT sub-bands for uplink transmission.

[0252] At this time, the base station can send an indicator to the terminal to indicate the allocated LBT sub-band and the interleaving structure of the LBT sub-bands. The LBT sub-bands and the interleaving structure can be encoded together or encoded individually and sent to the terminal.

[0253] The indicator for notifying the terminal of the LBT sub-bands and the interleaving structure may use the bitmap method or the RIV method. For example, the base station can use the indicator to notify the specific position of each LBT sub-band and the interleaving structure in the LBT sub-band in bits by the bitmap method. Or, the base station can use the indicator to notify the start position and length of the LBT sub-band, and notify the terminal of the index (or position) of the start interleave and the length according to the interleaving structure.

[0254] That is, the base station can notify the terminal of the position of the continuously allocated LBT sub-bands and the index (or position) of the PRB with the interleaving structure in the bitmap method or the RIV method.

[0255] Specifically, the base station can allocate continuous LBT sub-bands allocated for performing the LBT operation and allocate PRBs to each LBT sub-band with an interleaving structure at regular intervals so that the terminal can perform uplink transmission using the unlicensed band.

[0256] The base station may encode information related to the position of consecutively assigned LBT subbands and information related to PRBs having an interlaced structure (e.g., an index) together or separately and transmit them to the terminal. In this case, the information encoded together or separately may be transmitted in DCI. In this case, DCI may further include an indicator indicating whether or not the BWP PRB has an interlaced structure.

[0257] The base station can transmit information related to the position of consecutively assigned LBT subbands and information related to interlaced PRBs (e.g., an index) to the terminal in DCI using a bitmap or RIV method, and the RIV or bitmap method may be used selectively depending on specific conditions.

[0258] For example, if the specific condition is the subcarrier interval, the bitmap method or the RIV method may be selectively used depending on the value of the subcarrier interval.

[0259] For example, if the subcarrier interval is 15 kHz, the base station can use the RIV method to encode the positions of the continuously allocated LBT subbands and the indices of the interlaced PRBs together or separately, and transmit them to the terminal in DCI.

[0260] In other words, the base station can encode the start position and length (or position) of consecutively assigned LBT subbands and transmit them to the terminal in DCI. The base station can also encode information indicating the start index of the interlaced PRB and the length index of the consecutively assigned PRB separately from the information related to the position of the consecutively assigned LBT subbands and include it in the DCI, or encode it together with the information related to the position of the previous consecutively assigned LBT subband and include it in the DCI and transmit it to the terminal.

[0261] Alternatively, if the subcarrier interval is 15 kHz, the base station can use a bitmap scheme to encode the positions of the consecutively assigned LBT subbands and the indices of the interlaced PRBs together or separately, and transmit them to the terminal in DCI.

[0262] In other words, the base station can encode the start position and length (or position) of consecutively assigned LBT subbands and transmit them to the terminal in DCI. The base station can also encode information indicating the start index of the interlaced PRB and the length index of the consecutively assigned PRB separately from the information related to the position of the consecutively assigned LBT subbands and include it in the DCI, or encode it together with the information related to the position of the previous consecutively assigned LBT subband and include it in the DCI and transmit it to the terminal.

[0263] Alternatively, if the subcarrier interval is 30 kHz, the base station can use the RIV method to indicate the start position and length of the continuously allocated LBT subbands, and for the PRB indices having an interlaced structure, it can encode them together or individually using the bitmap method to provide full flexibility, and transmit them to the terminal in DCI.

[0264] In other words, the base station can encode the start position and length of the continuously allocated LBT subbands using the RIV method, include them in the DCI, and transmit them to the terminal. Furthermore, the base station can indicate the index of the interlaced PRB assigned to the terminal using specific bits. These specific bits, representing the index of the interlaced PRB, can be encoded separately from the LBT subband position information encoded using the RIV method, included in the DCI, and transmitted to the terminal.

[0265] Alternatively, if the subcarrier interval is 30 kHz, the base station can use the RIV method to indicate the start position and length of the continuously allocated LBT subbands, and can also encode the indices of the interlaced PRB together or individually using the RIV method and transmit them to the terminal in DCI.

[0266] In other words, the base station can encode the start position and length of the continuously allocated LBT subbands using the RIV method, include them in the DCI, and transmit them to the terminal. Furthermore, the base station can indicate the index of the interlaced PRB assigned to the terminal using the RIV, encode specific bits separately from the LBT subband position information encoded using the RIV method, include them in the DCI, and transmit them to the terminal.

[0267] Alternatively, if the subcarrier interval is 30 kHz, the base station may use a bitmap scheme to encode together or individually the positions of the consecutively allocated LBT subbands and the indices of the interlaced PRBs, and transmit them to the terminal in DCI.

[0268] In other words, the base station can indicate the positions of consecutively allocated LBT subbands using a bitmap scheme with bits of a specific size, and these bits of a specific size may be included in the DCI and transmitted to the terminal. Furthermore, the base station can indicate the index of the interlaced PRB assigned to the terminal with specific bits, and these specific bits can be individually encoded, included in the DCI, and transmitted to the terminal.

[0269] Alternatively, the positions of the LBT subbands and the indices of the interlaced PRBs may be mapped to each other and defined by bit values, and each mapped bit value may be included in the DCI and transmitted to the terminal.

[0270] When the terminal receives a DCI containing information related to the LBT subband and the PRB having an interlaced structure, it can recognize the LBT subband for performing LBT operation. After performing LBT operation on the recognized LBT subband, it can transmit uplink data to the base station using the PRB included in the LBT subband where the LBT operation was successful.

[0271] When indicating the position of LBT subbands using a bitmap method, if N LBT subbands are assigned, the terminal can be instructed on the assigned LBT subbands using a bitmap of length N in the scheduling information provided by DCI. Furthermore, the number of states required to assign an interlaced index associated with one or more consecutive PRBs in the interlaced structure of each subband may be M(M+1) / 2. To represent such a state for assigning an interlaced index with bits, more than log2{M(M+1) / 2} bits are required. Therefore, to represent the interlaced index of a PRB, floor(log2{M(M+1) / 2} or ceiling(log2{M(M+1) / 2} bits may be required.

[0272] Therefore, if discontinuous LBT subband allocation is permitted, N bit(s) + ceiling(log2{M(M+1) / 2}) bits may be required for resource allocation for uplink transmission.

[0273] For NR-U operation, a single BWP consists of one or more LBT subbands, and in the case of uplink transmission, the base station can allocate resources for uplink transmission using an interlaced structure in consecutive LBT subbands so that the terminal is allocated uplink frequency resources from the base station, and the terminal can thereby receive resource allocation.

[0274] If uplink frequency resources are to be allocated only on continuous LBT subbands, the base station can instruct the terminal on the allocated resources using the same method used in the schemes that allow the allocation of resources on discontinuous subbands as described above.

[0275] In other words, when indicating the position of LBT subbands using a bitmap method, if N LBT subbands are assigned, the terminal can be instructed to use the scheduling information using DCI to assign the LBT subbands using a bitmap of length N. Furthermore, the number of states required to assign an interlace index associated with one or more consecutive PRBs in the interlace structure of each subband may be M(M+1) / 2. To represent such a state for assigning an interlace index with bits, more than log2{M(M+1) / 2} bits are required. Therefore, to represent the interlace index of a PRB, floor(log2{M(M+1) / 2} or ceiling(log2{M(M+1) / 2} bits may be required.

[0276] When allocating resources for uplink transmission using an interlaced structure only in consecutive LBT subbands, if the indices of the interlaced structures of the LBT subbands and PRBs are individually separated and instructed to the terminal, the number of LBT subbands contained within a single BWP increases, and as the M value in the interlaced structure of each subband increases, the number of states for uplink resource allocation may increase.

[0277] Therefore, since the number of bits in the Resource Allocation (RA) field for allocating uplink resources may increase, if resources for uplink transmission are allocated using an interlaced structure only on consecutive LBT subbands and scheduled to the terminal, the allocation information for the LBT subbands and the index from the interlaced structure allocation can both be encoded and scheduled to the terminal with an indicator.

[0278] The terminal can recognize the location of one or more LBT subbands and resource information for interlaced PRBs within those LBT subbands from the value of one RA field (or resource allocation information) contained in the scheduling information (or DCI) transmitted from the base station.

[0279] The terminal performs LBT for channel connection for each recognized LBT subband. If channel access is successful through the LBT operation, it can transmit uplink to the base station using that resource. The specific method is described below.

[0280] (Method 1) As shown in Figures 20 and 22, if only consecutive LBT subbands are assigned, and the number of LBT subbands is N, the number of possible combinations of consecutively assigned LBT subbands can be calculated using the following equation 7.

number

[0281] Furthermore, the number of states required to assign interlace indices to one or more consecutive PRBs in an interlaced structure can be M(M+1) / 2. When M(M+1) / 2 states are set, and one or more consecutive LBT subbands and one or more consecutive interlaced PRB indices are encoded and instructed to the terminal, the number of states for one or more consecutive LBT subbands and one or more consecutive interlaced PRBs may be set as shown in equation 8 below.

number

[0282] As an example shown in Figure 22, when the value of N is 4, the number of consecutively assignable LBT subband combinations is 10, and when the subcarrier interval is 15 kHz, the value of M can be 10, so the total number of states for one or more consecutive LBT subbands and one or more consecutive interlaced structures may be 550 states.

[0283] In this case, if the assigned LBT subband position is assigned using a bitmap, separately from the PRB index assigned in the interlaced structure, that is, if only 9 reserved states remain in 4 bits + 6 bits (55 states) = 10 bits, and only 9 states can be assigned for the additional already set mapping scheme in the interlaced structure, then the number of bits in the RA field for resource allocation can be the same as 10 bits. However, the method of encoding together based on the bit size of the same RA field can leave 474 states remaining compared to the individual encoding method. In other words, the method of encoding together can map 474 more states than the individual encoding method.

[0284] Therefore, this has the effect of increasing the flexibility for resource allocation in the base station resource allocation method using an already established mapping scheme. Furthermore, compared to the method of individually encoding LBT subbands and instructing terminals, the method of encoding and mapping one or more consecutive LBT subbands and one or more consecutive interlaced PRBs together, starting from when there are five or more LBT subbands, can reduce the number of bits required for resource allocation.

[0285] [Table 4]

[0286] Referring to Figure 20, one or more consecutive LBT subbands and consecutive interlace structures for Case 1) to Case 10) may be mapped sequentially in ascending order, calculated and / or set, and the calculated and / or set information may be transmitted to the terminal in an indicator. In this case, the indicator may be transmitted in the DCI, which is downlink control information that transmits uplink scheduling information.

[0287] For example, in the case of Figure 20, indices of PRBs having one or more consecutive LBT subbands and one or more consecutive interlaced structures may be sequentially mapped in the order of case 1) -> case 2) -> ... -> case 10) and transmitted to the terminal by an indicator.

[0288] Alternatively, the number of LBT subbands may be prioritized and mapped sequentially in ascending order, and calculated and / or set. The calculated and / or set information may be transmitted to the terminal using an indicator. In this case, the indicator may be transmitted as part of the DCI, which is downlink control information that transmits uplink scheduling information.

[0289] For example, in the case of Figure 20, the number of LBT subbands is prioritized and mapped in ascending order in the following order: case 1)->case 5)->case 8)->case 10)->case 2)->case 6)->case 9)->case 3)->case 7)->case 4), and this information may be transmitted to the terminal by the indicator.

[0290] The base station can calculate the information based on the M value determined by the number of LBT subbands configured in BWP and the subcarrier interval between them, allocate resources for uplink transmission to the terminal, and transmit a DCI containing resource allocation information related to the resources allocated to the terminal.

[0291] The terminal receives a DCI containing resource allocation information and can perform uplink transmission using one or more consecutive LBT subbands and one or more consecutive interlaced PRBs assigned to the terminal.

[0292] (Method 2) For each of the one or more LBT subbands, the RIV method used in LTE-LAA is used to allocate resources having one or more interlaced structures, and for RIVs with values ​​of M(M+1) / 2 or greater, the mapping pattern which is a predetermined resource mapping pattern used in LTE-LAA may be used.

[0293] For example, resource mapping patterns like those shown in Table 5 below may be used. [Table 5]

[0294] Table 5 shows RB START`l` represents the starting index of a contiguously assigned RB with an interlaced structure, and `l` represents the index of a contiguously assigned RB with an interlaced structure.

[0295] In this invention, the interval between individual RBs in the frequency domain in an interlaced structure with an M value is described as N=M, but is not limited to this, and the M value can have various values.

[0296] Hereinafter, N can represent the interval between individual RBs in the frequency domain within a single interlaced structure, and does not represent the number of LBT subbands as explained earlier in Figures 19 to 22. That is, if uplink resource allocation type 3 used in LTE-LAA is also applied to NR-U, then, using the index of a PRB with 10 interlaced structures at a 15kHz subcarrier interval as an example of a continuous interlaced structure in an LBT subband unit with a bandwidth of 20MHz, the resource mapping method already set up as shown in Table 5 may be used.

[0297] Alternatively, in addition to the M(M+1) / 2 states used to represent a total continuous interlaced structure, X additional states (for example, if M=10 at 15kHz SCS, the value of X is 8) may be used.

[0298] Here, the number of X for the already configured resource mapping, which is further set by the subcarrier interval, can be the same or different. Method 2 proposes a method that uses the same method but is encoded and indicated together with the LBT subband.

[0299] For example, number 7 can be applied as is, and number 8 may be modified to the lower number 9 before being applied.

number

[0300] Similar to Method 1, Method 2, as shown in Figure 20, may involve sequentially mapping one or more consecutive LBT subbands and consecutive interlace structures for Cases 1) to 10) in ascending order, calculating and / or setting the calculated and / or set information, which may be transmitted to the terminal in an indicator. In this case, the indicator may be transmitted in the DCI, which is downlink control information.

[0301] For example, in the case of Figure 20, indices of PRBs having one or more consecutive LBT subbands and one or more consecutive interlaced structures may be sequentially mapped in the order of case 1) -> case 2) -> ... -> case 10) and transmitted to the terminal by an indicator.

[0302] Alternatively, the number of LBT subbands may be prioritized and mapped sequentially in ascending order, and calculated and / or set. The calculated and / or set information may be transmitted to the terminal as an indicator. In this case, the indicator may be transmitted included in the DCI, which is downlink control information.

[0303] For example, in the case of Figure 20, the number of LBT subbands is given priority and mapped in ascending order in the following order: case 1)->case 5)->case 8)->case 10)->case 2)->case 6)->case 9)->case 3)->case 7)->case 4), and this information may be transmitted to the terminal using an indicator.

[0304] In this case, compared to method 1), the number of states included in the case of method 2 may be M(M+1) / 2 states for instructing the terminal to provide a total continuous interlaced structure, plus X additional states.

[0305] Uplink resource allocation type 3

[0306] Uplink resource allocation type 3 applied to LAA's SCell may be applied for NR-U. Resource allocation information for uplink resource allocation type 3 is resource blocks allocated to scheduled UEs.

number

number

[0307] Number of uplink RBs

number

number

number

number

number

[0308]

number

number

[0309] The method described in Figures 19 to 22, when DFT spreading OFDM is eliminated in the uplink transmission scheme, involves indexing with seven RB intervals and an interlaced structure, and then instructing the terminal using the method described in Figures 19 to 22.

[0310] However, if the terminal is configured to use DFT spread OFDM, the index of the interlaced RB, which is allocated with 7 RB intervals, may be set as a reserved index.

[0311] When a single BWP consists of one or more LBT subbands, the present invention compares an indicator that independently indicates an LBT subband allocated for push transmission with a method of setting and allocating PRBs in an interlaced structure. As the number of LBT subbands increases or the spacing between individual RBs in a frequency domain in a single interlaced structure increases, the number of states for indicating resource allocation information related to the resources allocated for push transmission (i.e., the location of one or more LBT subbands and resource allocation information for PRBs allocated in an interlaced structure within those LBT subbands) can be reduced.

[0312] Figure 23 is a flowchart illustrating yet another embodiment of the present invention, illustrating an example of a method for a terminal to receive resource allocation of unlicensed bandwidth from a base station and transmit uplink data.

[0313] Referring to Figure 23, the terminal can receive allocation information from the base station via downlink control information, indicating a continuous LBT subband and an interlaced PRB, in order to transmit uplink data using an unlicensed band. The terminal can then transmit uplink data to the base station using the allocated LBT subband and the interlaced PRB.

[0314] Specifically, the terminal can receive Downlink Control Information (DCI) from the base station for the allocation of at least one subband for transmitting PUSCH (Physical Uplink Shared Channel) and a plurality of resource blocks constituting each of the at least one subband (S23010).

[0315] Before receiving DCI from the base station, the terminal can receive RRC Configuration Information, which includes parameters for receiving DCI.

[0316] Multiple resource blocks may be allocated within the system bandwidth as described in Figures 20-22. For example, multiple resource blocks may be called PRBs and may be allocated in an interlaced structure, with a certain interval between them to occupy a certain portion (e.g., 80%) of the system bandwidth. Multiple PRBs having such an interlaced structure may be included in the allocated LBT subband.

[0317] In this case, the at least one allocated subband may be included in an activated bandwidth part (BWP) based on the first resource allocation information, and the at least one subband allocated for uplink transmission in a single BWP may be allocated consecutively.

[0318] Furthermore, the allocated multiple resource blocks may be included in an interlace structure that is allocated sequentially at regular intervals to the activated BWP based on the second resource allocation information.

[0319] DCI may include first resource allocation information related to the location of at least one assigned subband and second resource allocation information related to the locations of multiple assigned resource blocks, as described in Figures 20 to 22.

[0320] For example, DCI may include second resource allocation information related to the locations of multiple resource blocks having an interlaced structure and first resource allocation information related to the locations of assigned LBT subbands, and the second resource allocation information of multiple resource blocks having an interlaced structure and the first resource allocation information related to the locations of assigned LBT subbands may be encoded individually or together and included in DCI.

[0321] In this case, the second resource allocation information for multiple resource blocks having an interlaced structure and the first resource allocation information related to the position of the allocated LBT subband may be transmitted to the terminal using a bitmap or RIV indicator, as explained in Figures 20 to 22.

[0322] For example, the second resource allocation information for multiple resource blocks having an interlaced structure and the first resource allocation information related to the location of the allocated LBT subband may be indicated in a bitmap or RIV format depending on specific conditions.

[0323] In this case, as an example of specific conditions, second resource allocation information for multiple resource blocks having an interlaced structure in a bitmap or RIV manner based on the subcarrier interval value, and first resource allocation information related to the position of the allocated LBT subband may be transmitted to the terminal by an indicator.

[0324] For example, if the subcarrier interval is 15 kHz, the second resource allocation information for multiple resource blocks having an interlaced structure and the first resource allocation information for the allocated LBT subband may be included in the DCI using the RIV method.

[0325] In other words, the values ​​associated with the start index of multiple resource blocks having an interlaced structure and the indices of consecutively allocated resource blocks, as well as the start index of consecutively allocated LBT subbands and the indices of consecutively allocated LBT subbands, may be encoded individually or together and included in the DCI.

[0326] Alternatively, if the subcarrier interval is 15 kHz, the second resource allocation information for multiple resource blocks having an interlaced structure and the first resource allocation information for the allocated LBT subband may be transmitted to the terminal as an indicator using a bitmap method.

[0327] In other words, the specific locations of multiple resource blocks having an interlaced structure and consecutively allocated LBT subbands may be encoded individually or together by the value of each bit having a specific size and included in the DCI.

[0328] Alternatively, if the subcarrier interval is 30 kHz, the first resource allocation information for consecutively allocated LBT subbands may be included in the DCI using the RIV method, and the second resource allocation information for multiple resource blocks having an interlaced structure may be included in the DCI as an indicator using the bitmap method and transmitted to the terminal.

[0329] In other words, the start index of multiple resource blocks having an interlaced structure and the values ​​associated with the indices of consecutively allocated resource blocks, as well as the start index of consecutively allocated LBT subbands and the indices of consecutively allocated LBT subbands, may be encoded individually or together and included in the DCI.

[0330] Alternatively, if the subcarrier interval is 30 kHz, the second resource allocation information for multiple resource blocks having an interlaced structure and the first resource allocation information for the allocated LBT subband may be transmitted to the terminal as an indicator using a bitmap method.

[0331] In other words, the specific locations of multiple resource blocks having an interlaced structure and consecutively allocated LBT subbands may be encoded individually or together by the value of each bit having a specific size and included in the DCI.

[0332] When multiple resource blocks having an interlaced structure and the specific locations of consecutively allocated LBT subbands are encoded together and transmitted to the terminal in an indicator, the indices of the multiple resource blocks having an interlaced structure may be mapped to indicators indicating consecutively allocated LBT subbands, and indicators indicating the respective mapping states may be included in the DCI and transmitted to the terminal.

[0333] Subsequently, the terminal performs channel access as LBT operation on the consecutive LBT subbands instructed by DCI.

[0334] If the terminal successfully accesses a channel on a continuous LBT subband assigned to it, the terminal can then transmit the PUSCH to the base station using DCI to indicate a first resource allocation information that shows a continuous LBT subband and a second resource allocation information that shows multiple resource blocks allocated in an interlaced structure within the LBT subband (S23020).

[0335] If the terminal fails to access the channel on the allocated continuous LBT subband, it does not transmit the PUSCH to the base station. Figure 24 is a flowchart illustrating yet another embodiment of the present invention, which is an example of a method by which a base station allocates unlicensed band resources to a terminal to receive uplink data.

[0336] Referring to Figure 24, the base station can instruct the terminal using downlink control information to receive uplink data using an unlicensed band, providing allocation information indicating a continuous LBT subband and allocation information indicating a PRB with an interlaced structure, and can receive uplink data from the terminal using the allocated LBT subband and PRB with an interlaced structure.

[0337] Specifically, the base station can transmit to the terminal Downlink Control Information (DCI) for the allocation of at least one subband for transmitting PUSCH (Physical Uplink Shared Channel) and a plurality of resource blocks constituting each of the at least one subband (S24010).

[0338] Before transmitting DCI from the base station, the terminal can transmit RRC Configuration Information, which includes parameters for receiving DCI.

[0339] Multiple resource blocks may be allocated within the system bandwidth as described in Figures 20-22. For example, multiple resource blocks may be called PRBs and may be allocated in an interlaced structure, with a certain interval between them to occupy a certain portion (e.g., 80%) of the system bandwidth. Multiple PRBs having such an interlaced structure may be included in the allocated LBT subband.

[0340] In this case, the at least one allocated subband may be included in the activated bandwidth part (BWP) based on the first resource allocation information, and the at least one subband allocated for uplink transmission in a single BWP may be allocated consecutively.

[0341] Furthermore, the allocated multiple resource blocks may be included in an interlace structure that is allocated sequentially at regular intervals to the activated BWP based on the second resource allocation information. The DCI may include first resource allocation information related to the location of at least one allocated subband and second resource allocation information related to the locations of the allocated multiple resource blocks, as described in Figures 20 to 22.

[0342] For example, DCI may include second resource allocation information related to the locations of multiple resource blocks having an interlaced structure and first resource allocation information related to the locations of assigned LBT subbands. The second resource allocation information for multiple resource blocks having an interlaced structure and the first resource allocation information related to the locations of assigned LBT subbands may be encoded individually or together and included in DCI.

[0343] In this case, the second resource allocation information for multiple resource blocks having an interlaced structure and the first resource allocation information related to the position of the allocated LBT subband may be transmitted to the terminal using a bitmap or RIV indicator, as explained in Figures 20 to 22.

[0344] For example, the second resource allocation information for multiple resource blocks having an interlaced structure and the first resource allocation information related to the location of the allocated LBT subband may be indicated in a bitmap or RIV format depending on specific conditions.

[0345] In this case, as an example of specific conditions, second resource allocation information for multiple resource blocks having an interlaced structure and first resource allocation information related to the position of the allocated LBT subband may be transmitted to the terminal by an indicator using a bitmap method or RIV method based on the value of the subcarrier interval.

[0346] For example, if the subcarrier interval is 15 kHz, the second resource allocation information for multiple resource blocks having an interlaced structure and the first resource allocation information for the allocated LBT subband may be included in the DCI using the RIV method.

[0347] In other words, the start index of multiple resource blocks having an interlaced structure and the values ​​associated with the indices of consecutively allocated resource blocks, as well as the start index of consecutively allocated LBT subbands and the indices of consecutively allocated LBT subbands, may be encoded individually or together and included in the DCI.

[0348] Alternatively, if the subcarrier interval is 15 kHz, the second resource allocation information for multiple resource blocks having an interlaced structure and the first resource allocation information for the allocated LBT subband may be transmitted to the terminal as an indicator using a bitmap method.

[0349] In other words, the specific locations of multiple resource blocks having an interlaced structure and consecutively allocated LBT subbands may be encoded individually or together by the value of each bit having a specific size and included in the DCI.

[0350] Alternatively, if the subcarrier interval is 30 kHz, the first resource allocation information for consecutively allocated LBT subbands may be included in the DCI using the RIV method, and the second resource allocation information for multiple resource blocks having an interlaced structure may be included in the DCI as an indicator using the bitmap method and transmitted to the terminal.

[0351] In other words, the start index of multiple resource blocks having an interlaced structure and the values ​​associated with the indices of consecutively allocated resource blocks, as well as the start index of consecutively allocated LBT subbands and the indices of consecutively allocated LBT subbands, may be encoded individually or together and included in the DCI.

[0352] Alternatively, if the subcarrier interval is 30 kHz, the second resource allocation information for multiple resource blocks having an interlaced structure and the first resource allocation information for the allocated LBT subband may be transmitted to the terminal as an indicator using a bitmap method.

[0353] In other words, the specific locations of multiple resource blocks having an interlaced structure and consecutively allocated LBT subbands may be encoded individually or together by the value of each bit having a specific size and included in the DCI.

[0354] When multiple resource blocks having an interlaced structure and the specific locations of consecutively allocated LBT subbands are encoded together and transmitted to the terminal in an indicator, the indices of the multiple resource blocks having an interlaced structure may be mapped to indicators indicating consecutively allocated LBT subbands, and indicators indicating the respective mapping states may be included in the DCI and transmitted to the terminal.

[0355] Subsequently, the base station can receive the PUSCH from the terminal using a continuous LBT subband allocated to the terminal in DCI and multiple resource blocks allocated in an interlaced structure (S24020).

[0356] The above description of the present invention is illustrative, and a person with ordinary skill in the art to which the invention pertains will understand that it can be readily modified into other specific forms without altering the technical idea or essential features of the invention. Accordingly, the embodiments described above should be understood in all respects as illustrative and not limiting. For example, each component described as a single type may be implemented in a distributed manner, and similarly, components described as distributed may be implemented in a combined manner.

[0357] The scope of the present invention is indicated more by the claims described below than by the detailed description above, and all modified or altered forms derived from the meaning and scope of the claims and the concept of equivalents thereto should be interpreted as being included within the scope of the present invention. [Explanation of symbols]

[0358] 100 devices 110 processors 120 Communication Modules 130 memory 140 User Interfaces 150 display units 200 base stations

Claims

1. A terminal in a wireless communication system, Communication module; and Includes a processor that controls the aforementioned communication module, The aforementioned processor, The base station receives Downlink Control Information (DCI) for the allocation of at least one subband for transmitting PUSCH (Physical Uplink Shared Channel) and multiple resource blocks. The PUSCH is transmitted to the base station using the multiple resource blocks received using the DCI. The DCI includes first resource allocation information related to the location of at least one subband and second resource allocation information related to the locations of the plurality of resource blocks, The at least one subband is included in the activated bandwidth portion (bandwidth part: BWP) based on the first resource allocation information, A terminal in which the plurality of resource blocks are included in an interlaced structure that is allocated sequentially at regular intervals to the activated BWP based on the second resource allocation information.

2. The terminal according to claim 1, wherein the at least one subband is allocated consecutively within the activated BWP based on the first resource allocation information.

3. The terminal according to claim 1, wherein the first resource allocation information relating to the location of the at least one subband is included in the DCI in the RIV (Resource Indication Value) format.

4. The terminal according to claim 1, wherein the second resource allocation information relating to the positions of the plurality of resource blocks is included in the DCI in a bitmap or RIV (Resource Indication Value) manner by subcarrier spacing.

5. The terminal according to claim 4, wherein, when the subcarrier interval is 30 kHz, the second resource allocation information relating to the positions of the plurality of resource blocks is included in the DCI in the bitmap format, and the positions of the plurality of resource blocks are indicated by each bit value included in the second resource allocation information based on the bitmap format.

6. When the subcarrier interval is 15 kHz, the second resource allocation information related to the positions of the plurality of resource blocks is included in the DCI in the RIV method. The terminal according to claim 4, wherein the second resource allocation information includes the start index of the plurality of resource blocks and the number of the plurality of resource blocks based on the RIV method.

7. The terminal according to claim 2, wherein the first resource allocation information includes the starting position and number of at least one subband.

8. The terminal according to claim 7, wherein both the first resource allocation information and the second resource allocation information are encoded and included in the DCI.

9. The terminal according to claim 8, wherein the instruction information, in which both the first resource allocation information and the second resource allocation information are encoded, is calculated sequentially in ascending order, prioritizing either the number of at least one subband or the start index of the plurality of resource blocks.

10. The terminal according to claim 1, wherein the plurality of resource blocks are included in the interlaced structure across at least one subband where Listen Before Talk (LBT) operation for channel access in an unlicensed band is performed.

11. The operation method of a terminal in a wireless communication system is: The steps include receiving Downlink Control Information (DCI) from a base station for the allocation of at least one subband and multiple resource blocks for the transmission of PUSCH (Physical Uplink Shared Channel); and The step includes transmitting the PUSCH to the base station using the plurality of resource blocks received using the DCI, The DCI includes first resource allocation information related to the location of at least one subband and second resource allocation information related to the locations of the plurality of resource blocks, A method wherein the at least one subband is included in an activated bandwidth portion (BWP) based on the first resource allocation information, and the plurality of resource blocks are included in an interlace structure that is allocated sequentially at regular intervals to the activated BWP based on the second resource allocation information.

12. The method according to claim 11, wherein the at least one subband is allocated consecutively within the activated BWP based on the first resource allocation information.

13. The method according to claim 11, wherein the first resource allocation information relating to the position of the at least one subband is included in the DCI in the RIV (Resource Indication Value) scheme.

14. The method according to claim 11, wherein the second resource allocation information relating to the positions of the plurality of resource blocks is included in the DCI in a bitmap or RIV (Resource Indication Value) manner by subcarrier spacing.

15. The method according to claim 14, wherein, when the subcarrier interval is 30 kHz, the second resource allocation information relating to the positions of the plurality of resource blocks is included in the DCI in the bitmap format, and the positions of the plurality of resource blocks are indicated by each bit value included in the second resource allocation information based on the bitmap format.

16. The method according to claim 14, wherein, when the subcarrier interval is 15 kHz, the second resource allocation information relating to the positions of the plurality of resource blocks is included in the DCI in the RIV scheme, and the second resource allocation information includes the start index of the plurality of resource blocks and the number of the plurality of resource blocks based on the RIV scheme.

17. The method according to claim 16, wherein the first resource allocation information includes the starting position and number of at least one subband.

18. The method according to claim 17, wherein both the first resource allocation information and the second resource allocation information are encoded and included in the DCI.

19. The method according to claim 18, wherein the instruction information, in which both the first resource allocation information and the second resource allocation information are encoded, is calculated sequentially in ascending order, prioritizing either the number of at least one subband or the starting index of the plurality of resource blocks.

20. The method according to claim 1, wherein the plurality of resource blocks are included in the interlaced structure across at least one subband where Listen Before Talk (LBT) operation for channel access in an unlicensed band is performed.

21. A base station in a wireless communication system, Communication module; and Includes a processor that controls the aforementioned communication module, The aforementioned processor, The terminal receives Downlink Control Information (DCI) for the allocation of at least one subband and multiple resource blocks for the transmission of PUSCH (Physical Uplink Shared Channel). The multiple resource blocks transmitted using the DCI receive the PUSCH transmitted from the terminal, The DCI includes first resource allocation information related to the location of at least one subband and second resource allocation information related to the locations of the allocated plurality of resource blocks, A base station in which at least one subband is included in an activated bandwidth portion (BWP) based on the first resource allocation information, and the plurality of resource blocks are included in an interlaced structure in which they are continuously allocated at regular intervals to the activated BWP based on the second resource allocation information.

Images