WO2019221475A1 - Method and device for transmitting harq feedback information in unlicensed band - Google Patents

Abstract

The present embodiments relate to a method and a device for transmitting HARQ feedback information in an unlicensed band. One embodiment provides a method for a terminal transmitting HARQ feedback information in an unlicensed band, the method comprising the steps of: receiving downlink control information including resource allocation information for a downlink data channel (PDSCH) in an unlicensed band; receiving HARQ timing indication information for transmitting HARQ feedback information in the unlicensed band; and transmitting the HARQ feedback information in the unlicensed band according to the HARQ timing indication information.

Description

Method and apparatus for transmitting HARQ feedback information in unlicensed band

The present embodiments propose a method and apparatus for transmitting HARQ feedback information in an unlicensed band in a next generation wireless access network (hereinafter, referred to as "NR").

3GPP recently approved a study item "Study on New Radio Access Technology" for the study of next-generation radio access technology (that is, 5G radio access technology), and based on this, the RAN WG1 for each NR (New Radio) Designs for frame structures, channel coding & modulation, waveforms and multiple access schemes are in progress. NR is required to be designed to satisfy various QoS requirements required for each segmented and detailed usage scenario as well as improved data rate compared to LTE.

As typical usage scenarios of NR, enhancement mobile broadband (eMBB), massive machine type communication (MMTC) and ultra reliable and low latency communications (URLLC) are defined, and flexible frame structure compared to LTE to satisfy the needs of each usage scenario. Design is required.

Each service scenario has different requirements for data rates, latency, reliability, coverage, and so on, through the frequency bands that make up any NR system. As a method for efficiently satisfying the needs of each usage scenario, based on different numerology (eg, subcarrier spacing, subframe, transmission time interval, etc.) There is a need for a method of efficiently multiplexing radio resource units of a network.

As part of this aspect, there is a need for a design for transmitting HARQ feedback information for the reception of a downlink data channel (PDSCH) using an unlicensed band in the NR.

Embodiments of the present disclosure may provide a specific method and apparatus capable of transmitting HARQ feedback information for reception of a downlink data channel in an unlicensed band.

In addition, embodiments of the present disclosure may provide a specific method and apparatus capable of transmitting an uplink control channel (PUCCH) including various uplink control information in an unlicensed band.

In one aspect, the present embodiment is a method for transmitting HARQ feedback information in the unlicensed band, the terminal, receiving downlink control information including resource allocation information for the downlink data channel (PDSCH) in the unlicensed band, The method may include receiving HARQ timing indication information for transmitting HARQ feedback information in the unlicensed band and transmitting HARQ feedback information in the unlicensed band according to the HARQ timing indication information.

In another aspect, embodiments of the present invention provide a method for a base station to receive HARQ feedback information in an unlicensed band, transmitting downlink control information including resource allocation information for a downlink data channel (PDSCH) in an unlicensed band, The method may include transmitting HARQ timing indication information for transmitting HARQ feedback information in the unlicensed band and receiving HARQ feedback information in the unlicensed band according to the HARQ timing indication information.

In another aspect, the present embodiment, in a terminal transmitting HARQ feedback information in an unlicensed band, receives downlink control information including resource allocation information for a downlink data channel (PDSCH) in an unlicensed band, and the unlicensed band The UE may include a receiver for receiving HARQ timing indication information for transmitting HARQ feedback information and a transmitter for transmitting HARQ feedback information in the unlicensed band according to the HARQ timing indication information.

In another aspect, the present embodiments, in the base station receiving HARQ feedback information in the unlicensed band, transmits downlink control information including resource allocation information for the downlink data channel (PDSCH) in the unlicensed band, and the unlicensed band A base station may include a transmitter for transmitting HARQ timing indication information for transmitting HARQ feedback information and a receiver for receiving HARQ feedback information in an unlicensed band according to HARQ timing indication information.

According to the present embodiments, a method and apparatus for transmitting HARQ feedback information in an unlicensed band for transmitting HARQ feedback information for reception of a downlink data channel in an unlicensed band can be provided.

According to the present embodiments, a specific method and apparatus capable of transmitting an uplink control channel (PUCCH) including various uplink control information in an unlicensed band can be provided.

1 is a diagram schematically illustrating a structure of an NR wireless communication system to which an embodiment of the present invention may be applied.

2 is a view for explaining a frame structure in an NR system to which the present embodiment can be applied.

3 is a diagram for describing a resource grid supported by a radio access technology to which the present embodiment can be applied.

FIG. 4 is a diagram for describing a bandwidth part supported by a radio access technology to which the present embodiment can be applied.

5 is a diagram exemplarily illustrating a synchronization signal block in a radio access technology to which the present embodiment can be applied.

6 is a diagram for explaining a random access procedure in a radio access technology to which the present embodiment can be applied.

7 is a diagram for explaining CORESET.

FIG. 8 is a diagram illustrating an example of symbol level alignment among different SCSs in different SCSs to which the present embodiment can be applied.

FIG. 9 is a diagram illustrating a conceptual example of a bandwidth part to which the present embodiment can be applied.

10 is a diagram illustrating a procedure of transmitting HARQ feedback information by an MS in an unlicensed band according to an embodiment.

11 is a diagram illustrating a procedure for receiving HARQ feedback information in an unlicensed band by a base station according to an embodiment.

12 illustrates an example of performing LBT for wireless communication in an unlicensed band according to an embodiment.

13 to 17 are diagrams for describing a DCI format according to an embodiment.

18 and 19 illustrate HARQ feedback windows according to an embodiment.

20 is a diagram illustrating a configuration of a user terminal according to another embodiment.

21 is a diagram illustrating a configuration of a base station according to another embodiment.

Some embodiments of the present disclosure are described in detail below with reference to exemplary drawings. In adding reference numerals to components of each drawing, the same components may have the same reference numerals as much as possible even though they are shown in different drawings. In addition, in describing the present embodiments, when it is determined that a detailed description of a related known configuration or function may obscure the gist of the present invention, the detailed description may be omitted. When "include", "have", "consist", or the like, as used herein, other parts may be added unless "only" is used. In the singular form, the plural may include the plural unless specifically stated otherwise.

In addition, in describing the components of the present disclosure, terms such as first, second, A, B, (a), and (b) may be used. These terms are only to distinguish the components from other components, and the terms are not limited in nature, order, order, or number of the components.

In the description of the positional relationship of components, when two or more components are described as being "connected", "coupled" or "connected", the two or more components are directly "connected", "coupled" or "connected". It may be understood, but it should be understood that two or more components and other components may be further “interposed” and “connected”, “coupled” or “connected”. Here, the other components may be included in one or more of two or more components that are "connected", "coupled" or "connected" to each other.

In the description of the temporal flow relations with respect to the components, the operation method, the fabrication method, and the like, for example, the temporal and posterior relations are defined as "after," "after," "after," and "before. Or where flow-benefit relationships are described, they may also include cases where they are not continuous unless "right" or "direct" is used.

On the other hand, if a numerical value or corresponding information (e.g., a level, etc.) for the component is mentioned, the numerical value or the corresponding information may be various factors (e.g., process factors, internal or external shocks, It may be interpreted as including an error range that may be caused by noise).

The wireless communication system herein refers to a system for providing various communication services such as voice and data packets using radio resources, and may include a terminal, a base station or a core network.

The embodiments disclosed below can be applied to a wireless communication system using various radio access technologies. For example, embodiments of the present invention may include code division multiple access (CDMA), frequency division multiple access (FDMA), timedivision multiple access (TDMA), orthogonal frequency division multiple access (OFDMA), and single carrier frequency division multiple access (SC-FDMA). Alternatively, the present invention may be applied to various radio access technologies such as non-orthogonal multiple access (NOMA). In addition, the wireless access technology may mean not only a specific access technology, but also a communication technology for each generation established by various communication consultation organizations such as 3GPP, 3GPP2, WiFi, Bluetooth, IEEE, and ITU. For example, CDMA may be implemented with a radio technology such as universal terrestrial radio access (UTRA) or CDMA2000. TDMA may be implemented with wireless technologies such as global system for mobile communications (GSM) / general packet radio service (GPRS) / enhanced data rates for GSM evolution (EDGE). OFDMA may be implemented in wireless technologies such as Institute of Electrical and Electronics Engineers (IEEE) 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802-20, evolved UTRA (E-UTRA), and the like. IEEE 802.16m is an evolution of IEEE 802.16e and provides backward compatibility with systems based on IEEE 802.16e. UTRA is part of a universal mobile telecommunications system (UMTS). 3rd generation partnership project (3GPP) long term evolution (LTE) is part of evolved UMTS (E-UMTS) using evolved-UMTS terrestrial radio access (E-UTRA), employing OFDMA in downlink and SC- in uplink FDMA is adopted. As such, the embodiments may be applied to a wireless access technology that is currently disclosed or commercialized, and may be applied to a wireless access technology that is currently under development or will be developed in the future.

On the other hand, the terminal in the present specification is a comprehensive concept that means a device including a wireless communication module for communicating with a base station in a wireless communication system, WCDMA, LTE, NR, HSPA and IMT-2020 (5G or New Radio) In addition to the user equipment (UE), as well as MS (Mobile Station), User Interface (UT), Subscriber Station (SS), wireless device (wireless device) and the like in GSM should be interpreted. In addition, the terminal may be a user portable device such as a smart phone according to a usage form, and may mean a vehicle, a device including a wireless communication module in a vehicle, and the like in a V2X communication system. In addition, in the case of a machine type communication system, it may mean an MTC terminal, an M2M terminal, a URLLC terminal, etc. equipped with a communication module to perform machine type communication.

A base station or a cell of the present specification refers to an end point that communicates with a terminal in terms of a network, and includes a Node-B, an evolved Node-B, an eNB, a gNode-B, a Low Power Node, and an LPN. Sector, site, various types of antenna, base transceiver system (BTS), access point, access point (for example, transmission point, reception point, transmission point and reception point), relay node ), A mega cell, a macro cell, a micro cell, a pico cell, a femto cell, a remote radio head (RRH), a radio unit (RU), and a small cell. In addition, the cell may mean a bandwidth part (BWP) in the frequency domain. For example, the serving cell may mean an activation BWP of the terminal.

Since the above-mentioned various cells have a base station that controls one or more cells, the base station may be interpreted in two meanings. 1) the device providing the mega cell, the macro cell, the micro cell, the pico cell, the femto cell, the small cell in relation to the wireless area, or 2) the wireless area itself. In 1) all devices that provide a given radio area are controlled by the same entity or interact with each other to cooperatively configure the radio area to the base station. According to the configuration of the wireless area, a point, a transmission point, a transmission point, a reception point, and the like become one embodiment of a base station. In 2), the base station may indicate the radio area itself that receives or transmits a signal from a viewpoint of a user terminal or a neighboring base station.

In the present specification, a cell refers to a component carrier having a coverage of a signal transmitted from a transmission / reception point or a signal transmitted from a transmission point or a transmission / reception point, and the transmission / reception point itself. Can be.

Uplink (UL, or uplink) means a method for transmitting and receiving data to the base station by the terminal, downlink (Downlink, DL, or downlink) means a method for transmitting and receiving data to the terminal by the base station do. Downlink (downlink) may mean a communication or communication path from the multiple transmission and reception points to the terminal, uplink (uplink) may mean a communication or communication path from the terminal to the multiple transmission and reception points. In this case, in the downlink, the transmitter may be part of multiple transmission / reception points, and the receiver may be part of the terminal. In addition, in uplink, a transmitter may be part of a terminal, and a receiver may be part of multiple transmission / reception points.

Uplink and downlink transmit and receive control information through a control channel such as a physical downlink control channel (PDCCH), a physical uplink control channel (PUCCH), a physical downlink shared channel (PDSCH), a physical uplink shared channel (PUSCH), and the like. Configure the same data channel to send and receive data. Hereinafter, a situation in which a signal is transmitted and received through a channel such as a PUCCH, a PUSCH, a PDCCH, and a PDSCH may be described in the form of 'sending and receiving a PUCCH, a PUSCH, a PDCCH, and a PDSCH.'

For clarity, the following description focuses on the 3GPP LTE / LTE-A / NR (New RAT) communication system, but the present technical features are not limited to the communication system.

After researching 4G (4th-Generation) communication technology, 3GPP develops 5G (5th-Generation) communication technology to meet the requirements of ITU-R's next generation wireless access technology. Specifically, 3GPP develops a new NR communication technology separate from LTE-A pro and 4G communication technology, which is an enhancement of LTE-Advanced technology to the requirements of ITU-R with 5G communication technology. Both LTE-A pro and NR mean 5G communication technology. Hereinafter, 5G communication technology will be described based on NR when a specific communication technology is not specified.

Operational scenarios in NR defined various operational scenarios by adding considerations to satellites, automobiles, and new verticals in the existing 4G LTE scenarios.In terms of services, they have eMBB (Enhanced Mobile Broadband) scenarios and high terminal density. Supports a range of mass machine communication (MMTC) scenarios that require low data rates and asynchronous connections, and Ultra Reliability and Low Latency (URLLC) scenarios that require high responsiveness and reliability and support high-speed mobility. .

In order to satisfy this scenario, NR discloses a wireless communication system using a new waveform and frame structure technology, low latency technology, mmWave support technology, and forward compatible technology. In particular, the NR system proposes various technological changes in terms of flexibility in order to provide forward compatibility. The main technical features of the NR will be described with reference to the drawings below.

<NR system general>

1 is a diagram schematically illustrating a structure of an NR system to which the present embodiment may be applied.

Referring to FIG. 1, an NR system is divided into a 5G core network (5GC) and an NR-RAN part, and the NG-RAN controls a user plane (SDAP / PDCP / RLC / MAC / PHY) and a user equipment (UE). It consists of gNB and ng-eNBs that provide planar (RRC) protocol termination. The gNB interconnects or gNBs and ng-eNBs are interconnected via an Xn interface. gNB and ng-eNB are each connected to 5GC through the NG interface. The 5GC may be configured to include an access and mobility management function (AMF) that is in charge of a control plane such as a terminal access and mobility control function, and a user plane function (UPF), which is in charge of a control function in user data. NR includes support for sub-6 GHz frequency bands (FR1, Frequency Range 1) and 6 GHz and higher frequency bands (FR2, Frequency Range 2).

gNB means a base station providing the NR user plane and control plane protocol termination to the terminal, ng-eNB means a base station providing the E-UTRA user plane and control plane protocol termination to the terminal. The base station described in the present specification should be understood to mean gNB and ng-eNB, and may be used to mean gNB or ng-eNB separately.

<NR Waveforms, Neutral and Frame Structures>

In NR, a CP-OFDM waveform using a cyclic prefix is used for downlink transmission, and a CP-OFDM or DFT-s-OFDM is used for uplink transmission. OFDM technology is easy to combine with Multiple Input Multiple Output (MIMO), and has the advantage of using a low complexity receiver with high frequency efficiency.

On the other hand, in NR, since the requirements for data rate, delay rate, and coverage are different for each of the three scenarios described above, it is necessary to efficiently satisfy the requirements for each scenario through a frequency band constituting an arbitrary NR system. . To this end, a technique for efficiently multiplexing a plurality of different numerology-based radio resources has been proposed.

Specifically, the NR transmission neuron is determined based on sub-carrier spacing and cyclic prefix (CP), and μ is used as an exponent value of 2 based on 15 kHz as shown in Table 1 below. Is changed to.

μ	Subcarrier spacing	Cyclic prefix	Supported for data	Supported for synch
0	15	Normal	Yes	Yes
One	30	Normal	Yes	Yes
2	60	Normal, Extended	Yes	No
3	120	Normal	Yes		Yes
4	240	Normal	No	Yes

As shown in Table 1 above, the NR's neuronality may be classified into five types according to the subcarrier spacing. This is different from the fixed subcarrier spacing of LTE, one of the 4G communication technologies. Specifically, the subcarrier spacing used for data transmission in NR is 15, 30, 60, 120 kHz, and the subcarrier spacing used for synchronous signal transmission is 15, 30, 12, 240 kHz. In addition, the extended CP applies only to 60 kHz subcarrier intervals. On the other hand, the frame structure (frame) in NR is a frame having a length of 10ms consisting of 10 subframes having the same length of 1ms (frame) is defined. One frame may be divided into half frames of 5 ms, and each half frame includes five subframes. In case of 15 kHz subcarrier spacing, one subframe consists of one slot, and each slot consists of 14 OFDM symbols. 2 is a view for explaining a frame structure in an NR system to which the present embodiment can be applied. Referring to FIG. 2, the slot is fixedly configured with 14 OFDM symbols in the case of a normal CP, but the length of the slot may vary depending on the subcarrier spacing. For example, in the case of a numerology having a 15 kHz subcarrier spacing, the slot has a length of 1 ms and the same length as the subframe. On the contrary, in the case of a numerology having a 30 kHz subcarrier interval, the slot is composed of 14 OFDM symbols, but two slots may be included in one subframe with a length of 0.5 ms. That is, the subframe and the frame are defined with a fixed time length, the slot is defined by the number of symbols, the time length may vary according to the subcarrier interval.

Meanwhile, NR defines a basic unit of scheduling as a slot, and also introduces a mini slot (or subslot or non-slot based schedule) to reduce transmission delay of a radio section. The use of a wide subcarrier spacing shortens the length of one slot in inverse proportion, thereby reducing the transmission delay in the radio section. The mini slot (or sub slot) is for efficient support for the URLLC scenario and can be scheduled in units of 2, 4, and 7 symbols.

In addition, unlike LTE, NR defines uplink and downlink resource allocation at a symbol level in one slot. In order to reduce the HARQ delay, a slot structure capable of transmitting HARQ ACK / NACK directly within a transmission slot has been defined, and this slot structure will be described as a self-contained structure.

NR is designed to support a total of 256 slot formats, of which 62 slot formats are used in 3GPP Rel-15. In addition, a combination of various slots supports a common frame structure constituting an FDD or TDD frame. For example, a slot structure in which all symbols of a slot are set to downlink, a slot structure in which all symbols are set to uplink, and a slot structure in which downlink symbol and uplink symbol are combined are supported. NR also supports that data transmission is distributed and scheduled in one or more slots. Accordingly, the base station can inform the terminal whether the slot is a downlink slot, an uplink slot, or a flexible slot by using a slot format indicator (SFI). The base station may indicate a slot format by indicating an index of a table configured through UE-specific RRC signaling using SFI, and may indicate the slot format dynamically through DCI (Downlink Control Information) or statically through RRC. You can also specify quasi-statically.

<NR Physical Resource>

With regard to physical resources in NR, antenna ports, resource grids, resource elements, resource blocks, bandwidth parts, etc. are considered do.

The antenna port is defined such that the channel on which the symbol is carried on the antenna port can be inferred from the channel on which another symbol on the same antenna port is carried. If the large-scale property of a channel on which a symbol on one antenna port is carried can be deduced from the channel on which the symbol on another antenna port is carried, then the two antenna ports are quasi co-located or QC / QCL. quasi co-location relationship. Here, the broad characteristics include one or more of delay spread, Doppler spread, frequency shift, average received power, and received timing.

3 is a diagram for describing a resource grid supported by a radio access technology to which the present embodiment can be applied.

Referring to FIG. 3, since the Resource Grid supports a plurality of numerologies in the same carrier, a resource grid may exist according to each numerology. In addition, the resource grid may exist according to the antenna port, subcarrier spacing, and transmission direction.

The resource block is composed of 12 subcarriers and is defined only in the frequency domain. In addition, a resource element is composed of one OFDM symbol and one subcarrier. Accordingly, as shown in FIG. 3, one resource block may vary in size depending on the subcarrier spacing. In addition, NR defines "Point A" serving as a common reference point for the resource block grid, a common resource block, a virtual resource block, and the like.

FIG. 4 is a diagram for describing a bandwidth part supported by a radio access technology to which the present embodiment can be applied.

In NR, unlike LTE, which has a fixed carrier bandwidth of 20 MHz, the maximum carrier bandwidth is set from 50 MHz to 400 MHz per subcarrier interval. Therefore, it is not assumed that all terminals use all of these carrier bandwidths. Accordingly, in NR, as shown in FIG. 4, a bandwidth part (BWP) may be designated within a carrier bandwidth and used by a UE. In addition, the bandwidth part is associated with one neuralology and consists of a subset of consecutive common resource blocks, and can be dynamically activated over time. The UE is configured with up to four bandwidth parts, respectively, uplink and downlink, and data is transmitted and received using the bandwidth part activated at a given time.

In the case of paired spectrum, uplink and downlink bandwidth parts are set independently, and in the case of unpaired spectrum, to prevent unnecessary frequency re-tunning between downlink and uplink operation. For this purpose, the bandwidth parts of the downlink and the uplink are configured in pairs so as to share the center frequency.

<NR initial connection>

In NR, the UE performs a cell search and random access procedure to access and communicate with a base station.

Cell search is a procedure in which a terminal synchronizes with a cell of a corresponding base station, obtains a physical layer cell ID, and acquires system information by using a synchronization signal block (SSB) transmitted by a base station.

5 is a diagram exemplarily illustrating a synchronization signal block in a radio access technology to which the present embodiment can be applied.

Referring to FIG. 5, an SSB is composed of a primary synchronization signal (PSS) and a secondary synchronization signal (SSS), which occupy one symbol and 127 subcarriers, respectively, three OFDM symbols, and a PBCH spanning 240 subcarriers.

The terminal monitors the SSB in the time and frequency domain to receive the SSB.

SSB can be transmitted up to 64 times in 5ms. A plurality of SSBs are transmitted in different transmission beams within 5ms, and the UE performs detection assuming that SSBs are transmitted every 20ms based on a specific beam used for transmission. The number of beams available for SSB transmission within 5 ms time may increase as the frequency band increases. For example, up to 4 SSB beams can be transmitted at 3 GHz or less, and up to 8 different SSBs can be transmitted at a frequency band of 3 to 6 GHz and up to 64 different beams at a frequency band of 6 GHz or more.

Two SSBs are included in one slot, and the start symbol and the number of repetitions in the slot are determined according to the subcarrier spacing.

On the other hand, SSB is not transmitted at the center frequency of the carrier bandwidth, unlike the SS of the conventional LTE. That is, the SSB may be transmitted even where the center of the system band is not, and when supporting broadband operation, a plurality of SSBs may be transmitted in the frequency domain. Accordingly, the terminal monitors the SSB using a synchronization raster, which is a candidate frequency position for monitoring the SSB. The carrier raster and the synchronization raster, which are the center frequency position information of the channel for initial access, are newly defined in the NR, and the synchronization raster has a wider frequency interval than the carrier raster, and thus supports fast SSB search of the terminal. Can be.

The UE may acquire the MIB through the PBCH of the SSB. The Master Information Block (MIB) includes minimum information for the UE to receive the remaining system information (RMSI) that the network broadcasts. In addition, the PBCH is information on the position of the first DM-RS symbol in the time domain, information for the UE to monitor SIB1 (for example, SIB1 neuronological information, information related to SIB1 CORESET, search space information, PDCCH Related parameter information, etc.), offset information between the common resource block and the SSB (the position of the absolute SSB in the carrier is transmitted through SIB1), and the like. Here, the SIB1 neuronological information is equally applied to some messages used in a random access procedure for accessing a base station after the terminal completes a cell search procedure. For example, the neuralology information of SIB1 may be applied to at least one of messages 1 to 4 for the random access procedure.

The aforementioned RMSI may refer to System Information Block 1 (SIB1), which is broadcast periodically (ex, 160ms) in a cell. SIB1 includes information necessary for the UE to perform an initial random access procedure and is periodically transmitted through the PDSCH. In order to receive the SIB1, the UE needs to receive the information of the neuterology used for the SIB1 transmission and the control resource set (CORESET) information used for the scheduling of the SIB1 through the PBCH. The UE checks scheduling information on SIB1 using SI-RNTI in CORESET and acquires SIB1 on PDSCH according to the scheduling information. The remaining SIBs other than SIB1 may be transmitted periodically or may be transmitted at the request of the terminal.

6 is a diagram for explaining a random access procedure in a radio access technology to which the present embodiment can be applied.

Referring to FIG. 6, when the cell search is completed, the terminal transmits a random access preamble for random access to the base station. The random access preamble is transmitted on the PRACH. Specifically, the random access preamble is transmitted to the base station through a PRACH composed of consecutive radio resources in a specific slot that is periodically repeated. In general, when a UE initially accesses a cell, a contention-based random access procedure is performed, and when a UE performs random access for beam failure recovery (BFR), a contention-free random access procedure is performed.

The terminal receives a random access response to the transmitted random access preamble. The random access response may include a random access preamble identifier (ID), a UL grant (uplink radio resource), a temporary C-RNTI (Temporary Cell-Radio Network Temporary Identifier), and a time alignment command (TAC). Since one random access response may include random access response information for one or more terminals, a random access preamble identifier may be included to indicate to which UE the included UL Grant, temporary C-RNTI, and TAC are valid. The random access preamble identifier may be an identifier for the random access preamble received by the base station. The TAC may be included as information for the UE to adjust uplink synchronization. The random access response may be indicated by a random access identifier on the PDCCH, that is, a Random Access-Radio Network Temporary Identifier (RA-RNTI).

The terminal receiving the valid random access response processes the information included in the random access response and performs the scheduled transmission to the base station. For example, the terminal applies a TAC and stores a temporary C-RNTI. In addition, by using the UL Grant, data or newly generated data stored in the buffer of the terminal is transmitted to the base station. In this case, information that can identify the terminal should be included.

Finally, the terminal receives a downlink message for contention resolution.

<NR CORESET>

The downlink control channel in NR is transmitted in a control resource set (CORESET) having a length of 1 to 3 symbols, and transmits up / down scheduling information, slot format index (SFI), and transmit power control (TPC) information. .

As such, the NR introduces the concept of CORESET to ensure system flexibility. CORESET (Control Resource Set) means a time-frequency resource for the downlink control signal. The terminal may decode the control channel candidate using one or more search spaces in the CORESET time-frequency resource. The QCL (Quasi CoLocation) assumption for each CORESET has been set, which is used to inform the analog beam direction in addition to the delay spread, Doppler spread, Doppler shift, and average delay, which are assumed by conventional QCL.

7 is a diagram for explaining CORESET.

Referring to FIG. 7, CORESET may exist in various forms within a carrier bandwidth in one slot, and CORESET in the time domain may be configured with up to three OFDM symbols. In addition, CORESET is defined as a multiple of six resource blocks up to the carrier bandwidth in the frequency domain.

The first CORESET is indicated through the MIB as part of the initial bandwidth part configuration to receive additional configuration information and system information from the network. After establishing a connection with the base station, the terminal may receive and configure one or more CORESET information through RRC signaling.

In this specification, frequency, frame, subframe, resource, resource block, region, band, subband, control channel, data channel, synchronization signal, various reference signals, various signals or various messages related to NR (New Radio) May be interpreted as meaning used in the past or present, or various meanings used in the future.

NR (New Radio)

3GPP recently approved “Study on New Radio Access Technology”, a study item for research on next-generation radio access technology (ie 5G radio access technology). Based on this, RAN WG1 has a frame structure for each new radio (NR). (frame structure), channel coding & modulation (waveform & multiple access scheme), etc. design is in progress. NR is required to be designed to meet various QoS requirements required for each detailed and detailed service scenario as well as improved data rate compared to LTE / LTE-Advanced.

As typical service scenarios for NR, enhancement Mobile BroadBand (eMBB), massive machine type communication (MMTC), and Ultra Reliable and Low Latency Communications (URLLC) are defined and meet the needs of each service scenario. As a method for doing so, a flexible frame structure design is required compared to LTE / LTE-Advanced.

Each service scenario is a frequency constituting an arbitrary NR system because the requirements for data rates, latency, reliability, coverage, etc. are different from each other. A radio resource unit based on different numerology (e.g., subcarrier spacing, subframe, TTI, etc.) as a method for efficiently satisfying each service scenario needs through a band. There is a need for a method of efficiently multiplexing (multiplexing).

As one method for this, TDM, FDM, or TDM / FDM based on one or a plurality of NR component carriers (s) for numerology having different subcarrier spacing values. As a method of supporting multiplexing and a scheduling unit in a time domain, a method of supporting one or more time units has been discussed. In this regard, in NR, a subframe is defined as a kind of time domain structure, and reference numerology is used to define a subframe duration. As the LTE, it was decided to define a single subframe duration consisting of 14 OFDM symbols of the same 15kHz sub-carrier spacing (SCS) -based normal CP overhead. Accordingly, in NR, the subframe has a time duration of 1 ms. However, unlike LTE, subframes of NR are absolute reference time durations, and slots and mini-slots are time units based on actual uplink / downlink data scheduling. ) Can be defined. In this case, the number of OFDM symbols and the y value of the corresponding slot are determined to have a value of y = 14 regardless of the SCS value in the case of normal CP.

Accordingly, any slot consists of 14 symbols, and according to the transmission direction of the slot, all symbols are used for DL transmission or all symbols are UL transmission (UL). It may be used for transmission or in the form of a downlink portion (DL portion) + a gap (gap) + uplink portion (UL portion).

In addition, a short slot time-domain scheduling interval for transmitting / receiving uplink / downlink data is defined based on a mini-slot consisting of fewer symbols than the slot in an arbitrary number (numerology) (or SCS). A scheduling interval may be set, or a long time-domain scheduling interval for transmitting / receiving uplink / downlink data may be configured through slot aggregation.

Particularly, in case of transmission / reception of latency critical data such as URLLC, it is based on 1ms (14 symbols) defined in a numerology-based frame structure with small SCS value such as 15kHz. When scheduling is performed by slot unit, it may be difficult to satisfy the latency requirement, so for this purpose, a mini slot consisting of fewer OFDM symbols than the corresponding slot is defined and based on this, critical to the same delay rate as the corresponding URLLC. (latency critical) may be defined so that scheduling is performed for data.

Alternatively, as described above, by supporting multiplexing by using TDM and / or FDM schemes, a number of numerology having different SCS values in one NR carrier is supported for each numerology. Scheduling data according to a latency requirement based on a defined slot (or mini slot) length is also considered. For example, as shown in FIG. 8 below, when the SCS is 60 kHz, since the symbol length is reduced by about 1/4 compared to the case of the SCS 15 kHz, when one slot is formed of the same 14 OFDM symbols, The slot length is 1ms, while the 60kHz-based slot length is reduced to about 0.25ms.

As described above, in NR, a method of satisfying the requirements of URLLC and eMBB by defining different SCSs or different TTI lengths is being discussed.

PDCCH

In NR and LTE / LTE-A systems, L1 control information such as DL assignment Downlink Control Information (DCI) and UL Grant DCI is transmitted and received through a PDCCH. A control channel element (CCE) is defined as a resource unit for transmitting the PDCCH, and in the NR, a control resource set (CORESET), which is a frequency / time resource for transmitting the PDCCH, may be set for each terminal. In addition, each CORESET may be configured with one or more search spaces consisting of one or more PDCCH candidates for monitoring the PDCCH. In the NR, the detailed description of the parts described in 3GPP TS 38.211 and TS 38.213 of the PDCCH-related details will be omitted for convenience. However, it may be included in the present disclosure.

Wider bandwidth operations

In the existing LTE system, a scalable bandwidth operation for any LTC CC is supported. That is, according to the frequency deployment scenario (deployment scenario) in any LTE carrier to configure a single LTE CC, a minimum bandwidth of 1.4 MHz to 20 MHz could be configured, the normal LTE terminal is one LTE For the CC, the transmit / receive capability of 20 MHz bandwidth was supported.

However, in the case of NR, the design is made to support NR terminals having different transmit / receive bandwidth capabilities through one wideband NR CC. Likewise, by configuring one or more bandwidth parts (BWP, bandwidth part (s)) composed of granular bandwidths for an arbitrary NR CC, a flexible (Bandwidth part configuration) and activation through different bandwidth part configuration (activation) for each terminal There is a need to support flexible bandwidth operation (wider bandwidth operation).

In more detail, in NR, one or more bandwidth parts may be configured through one serving cell configured from a terminal perspective, and the corresponding UE may include one downlink bandwidth part (s) in a serving cell. DL bandwidth part) and one uplink bandwidth part (UL bandwidth part) by activation (activation) was defined to be used for transmitting and receiving uplink / downlink data. In addition, when a plurality of serving cells are configured in a corresponding UE, that is, even for a UE to which a CA is applied, one downlink bandwidth part and / or an uplink bandwidth part are activated for each serving cell. By using the radio resources of the corresponding serving cell (serving cell) has been defined to use for transmitting and receiving uplink / downlink data.

In more detail, an initial bandwidth part for an initial access procedure of a terminal is defined in a serving cell, and one or more terminals are specified through dedicated RRC signaling for each terminal. A bandwidth part (s) may be configured, and a default bandwidth part for a fallback operation may be defined for each terminal.

However, in any serving cell, a plurality of downlink and / or uplink bandwidth parts are simultaneously activated and used according to the capability and bandwidth part (s) configuration of the terminal. In NR rel-15, only one downlink bandwidth part and one uplink bandwidth part may be activated at an arbitrary time in an arbitrary terminal in NR rel-15. .

NR-U

In the case of the unlicensed band, unlike the licensed band, any operator or individual may use the wireless communication service within the regulation of each country, not a wireless channel exclusively used by any operator. Accordingly, when providing NR service through unlicensed band, co-existence problem with various short-range wireless communication protocols such as WiFi, Bluetooth, and NFC already provided through the corresponding unlicensed band, and also between each NR operator or LTE provider There is a need for a solution to co-existence problems.

Accordingly, when providing the NR service through the unlicensed band, the power level of the radio channel or carrier to be used is sensed by transmitting the radio signal before transmitting the radio signal in order to avoid interference or collision between the respective radio communication services. There is a need to support a List Before Talk (LBT) based wireless channel access method for determining whether a channel or a carrier is available. In this case, if a specific radio channel or carrier in the unlicensed band is in use by another radio communication protocol or another operator, the radio communication service in the unlicensed band is not licensed band because there is a possibility that it will be restricted in providing NR service through the band. Unlike the wireless communication service through the LAN, the QoS required by the user cannot be guaranteed.

In particular, the NR-U deployment scenario of unlicensed band NR, unlike the existing LTE, which always supported unlicensed spectrum through carrier aggregation (CA) with a licensed spectrum. As a deployment scenario, an unlicensed band is considered because a stand-alone NR-U cell, a licensed band NR cell, or a dual connectivity (DC) based NR-U cell with an LTE cell is considered. It is necessary to design a data transmission / reception method to satisfy the minimum QoS in itself.

To this end, the present disclosure proposes a method for transmitting an uplink control channel of a terminal in an NR-U cell.

Hereinafter, a method of transmitting HARQ feedback information in an unlicensed band will be described in detail with reference to the accompanying drawings.

FIG. 10 is a diagram illustrating a procedure of a terminal performing List Before Talk (LBT) for wireless communication in an unlicensed band according to an embodiment.

Referring to FIG. 10, the terminal may receive downlink control information including resource allocation information for a downlink data channel (PDSCH) in an unlicensed band (S1000).

The terminal may receive the downlink data channel from the base station based on the resource allocation information included in the downlink control information. The terminal may transmit HARQ ACK / NACK feedback information to the base station as to whether to receive the downlink data channel.

Referring back to FIG. 10, the terminal may receive HARQ timing indication information for transmitting HARQ feedback information in the unlicensed band (S1010).

In the NR system, the UE may receive a resource allocation and feedback timing K1 value for an uplink control channel (PUCCH) for HARQ feedback through a DL assignment DCI. Alternatively, the feedback timing K1 value may be set through RRC signaling. The terminal may transmit the HARQ feedback information according to whether the downlink data channel is received based on the received resource allocation and the K1 value of the feedback timing.

However, when using the unlicensed band, when the corresponding unlicensed band is occupied by another node in the slot according to the K1 value indicated by the base station, it may be difficult for the terminal to transmit the PUCCH at the indicated timing. Therefore, according to an example, when the base station performs the LBT (Listen Before Talk) to access the unlicensed band, the UE may be notified of this, thereby triggering the PUCCH transmission of the UE.

According to an example, the PUCCH transmission triggering information may be defined through a UE-group common DCI format (UE-group common DCI format) for the corresponding PUCCH transmission triggering and transmitted through the UE-group common PDCCH. . Alternatively, the PUCCH transmission triggering information may be defined through a UE-specific DCI format (UE-specific DCI format) for the corresponding PUCCH transmission triggering may be transmitted through the UE-specific PDCCH (UE-specific PDCCH).

According to an example, the PUCCH triggering DCI format set separately may include resource allocation information for the PUCCH and a K3 value that is PUCCH transmission timing information. Here, the K3 value may be set as a timing gap between a reception slot of a corresponding PUCCH triggering DCI format and a PUCCH transmission slot of a terminal accordingly.

Alternatively, according to another example, the PUCCH triggering DCI format includes only PUCCH resource allocation information, and the K3 value is set by the base station through UE-specific / cell-specific higher layer signaling. Can be. Alternatively, the K3 value can be set to any fixed value.

Alternatively, according to another example, the PUCCH triggering DCI format may be set to include only a K3 value. In this case, the PUCCH resource allocation information to be transmitted by each terminal may be configured to be included in a DL assignment DCI format.

When a PUCCH resource for HARQ feedback of a UE for a PDSCH is allocated through a separate PUCCH triggering DCI format, which is distinguished from a downlink allocation DCI format, configuration or indication information for this is explicitly transmitted from a base station to a corresponding UE. Or may be signaled implicitly.

According to an example, whether PUCCH resources are allocated through the PUCCH triggering DCI format may be configured by a base station through UE-specific or cell-specific RRC signaling. In this case, based on configuration information on whether PUCCH resources for HARQ feedback are allocated through a separate PUCCH triggering DCI format, the UE receives PUCCH resource allocation information through a PUCCH resource indicator included in a downlink allocation DCI format. Or, it may be determined whether to receive PUCCH resource allocation information through PUCCH triggering DCI format reception for separate PUCCH resource allocation.

According to another example, the configuration information may be indicated through DCI format 1_0 or DCI format 1_1, which is a downlink allocation DCI format including PDSCH resource allocation information. That is, when allocating resources for the PDSCH, the downlink allocation DCI format may include delay indication information indicating whether to delay the transmission of HARQ feedback information. This means that information on whether PUCCH resource allocation information is made through a PUCCH resource indicator of a downlink allocation DCI format or is delayed through a separate PUCCH triggering DCI format transmitted subsequently is signaled through the corresponding downlink allocation DCI format. Can mean being.

In this case, according to an example, the corresponding DL allocation DCI format may include a separate information area for indicating delay indication information, for example, a PUCCH allocation flag information area. Alternatively, the downlink allocation DCI format may be configured to indicate this by using an existing information area, for example, a PUCCH resource indicator information area.

Alternatively, the information may be implicitly signaled. As an example of this, delay indication information may be indicated according to K1 value indicated through a corresponding downlink allocation DCI format. That is, if the K1 value is greater than or equal to a certain threshold, the PUCCH resource allocation may be indicated through a separate PUCCH triggering DCI format. Alternatively, when the K1 value is smaller than the corresponding threshold value, PUCCH resource allocation may be performed through the PUCCH resource indicator of the corresponding DL allocation DCI format. In this case, the specific threshold may be fixed to a specific value or may be set by cell base station through cell-sepcific / UE-specific RRC signaling.

Referring back to FIG. 10, the terminal may transmit HARQ feedback information in the unlicensed band according to the HARQ timing indication information (S1020).

When PUCCH resource allocation is performed through the PUCCH resource indicator of the corresponding DL allocation DCI format, the UE may transmit HARQ feedback information according to the received resource allocation information.

In contrast, when a delay for the transmission of HARQ feedback information is indicated, that is, when PUCCH resource allocation is indicated through the PUCCH triggering DCI format, the UE allocates resource allocation information and timing information for transmission of HARQ feedback information from the base station. The transmission of the HARQ feedback information may be delayed until receiving. After the downlink allocation DCI format is received, the UE may receive the PUCCH triggering DCI format. The UE may transmit HARQ feedback information according to resource allocation information and timing information for the uplink control channel included in the PUCCH triggering DCI format. In this case, the UE may transmit all HARQ ACK feedback information pending when the PUCCH triggering DCI format is received through the corresponding PUCCH.

Accordingly, a method and apparatus for transmitting HARQ feedback information in an unlicensed band for transmitting HARQ feedback information for reception of a downlink data channel in an unlicensed band can be provided.

In the above description, a case in which HARQ feedback information is transmitted as UL control information (UCI) is described, but the present invention is not limited thereto. According to an embodiment of the present disclosure, before the PUCCH triggering DCI format is received, if other UCI such as CQI / CSI reporting or SR other than HARQ feedback is present, the UE may transmit all UCIs being held in the corresponding PUCCH. Can be sent via

However, a maximum payload size or a maximum codebook size that can be transmitted through any PUCCH may be set by the base station. In addition, the configured maximum payload size or maximum codebook size may be UE-specific / cell-specific higher layer signaling, MAC CE signaling, or L1 control signaling. ) May be transmitted to the terminal. In this case, when the UE transmits the PUCCH according to the PUCCH triggering DCI format reception, if the payload size of the pending UCI exceeds the maximum payload size, the UE drops a specific UCI. It can be set to.

According to an example, a priority rule for UCI dropping may be set. For example, priority may be set for each UCI type. As an example of defining the priority for each UCI type, priority may be defined in the order of SR> HARQ ACK feedback> CQI / CSI reporting. Alternatively, priority may be defined in order of SR = HARQ ACK feedback> CQI / CSI reporting. However, this is merely an example and the present invention is not limited thereto. All cases of defining priorities for each other UCI type may be included in the scope of the present disclosure. In addition, when dropping occurs among UCIs of the same priority or the same type, the dropping is performed in order of the most recent UCI, or in the order of the oldest UCI. can do.

Accordingly, a specific method and apparatus for transmitting an uplink control channel (PUCCH) including various uplink control information in an unlicensed band can be provided.

11 is a diagram illustrating a procedure for receiving HARQ feedback information in an unlicensed band by a base station according to an embodiment.

Referring to FIG. 11, the base station may transmit downlink control information including resource allocation information for a downlink data channel (PDSCH) in an unlicensed band (S1100).

The base station may transmit the downlink data channel to the terminal based on the resource allocation information included in the downlink control information. The base station may receive HARQ ACK / NACK feedback information from the terminal as to whether to receive the downlink data channel.

Referring to FIG. 11 again, the base station may transmit HARQ timing indication information for receiving HARQ feedback information in the unlicensed band (S1110).

In the NR system, the base station may transmit a resource allocation and feedback timing K1 value for the uplink control channel (PUCCH) for HARQ feedback to the terminal through a DL assignment DCI. Alternatively, the feedback timing K1 value may be set through RRC signaling. The base station may receive HARQ feedback information according to whether the downlink data channel is received based on the received resource allocation and K1 value of feedback timing.

However, when using the unlicensed band, when the corresponding unlicensed band is occupied by another node in the slot according to the K1 value indicated by the base station, it may be difficult for the terminal to transmit the PUCCH at the indicated timing. Therefore, according to an example, when the base station performs the LBT (Listen Before Talk) to access the unlicensed band, the UE may be notified of this, thereby triggering the PUCCH transmission of the UE.

According to an example, the PUCCH transmission triggering information may be defined through a UE-group common DCI format (UE-group common DCI format) for the corresponding PUCCH transmission triggering and transmitted through the UE-group common PDCCH. . Alternatively, the PUCCH transmission triggering information may be defined through a UE-specific DCI format (UE-specific DCI format) for the corresponding PUCCH transmission triggering may be transmitted through the UE-specific PDCCH (UE-specific PDCCH).

According to an example, the PUCCH triggering DCI format set separately may include resource allocation information for the PUCCH and a K3 value that is PUCCH transmission timing information. Here, the K3 value may be set as a timing gap between a reception slot of a corresponding PUCCH triggering DCI format and a PUCCH transmission slot of a terminal accordingly.

Alternatively, according to another example, the PUCCH triggering DCI format includes only PUCCH resource allocation information, and the K3 value is set by the base station through UE-specific / cell-specific higher layer signaling. Can be. Alternatively, the K3 value can be set to any fixed value.

Alternatively, according to another example, the PUCCH triggering DCI format may be set to include only a K3 value. In this case, the PUCCH resource allocation information to be transmitted by each terminal may be configured to be included in a DL assignment DCI format.

When a PUCCH resource for HARQ feedback of a UE for a PDSCH is allocated through a separate PUCCH triggering DCI format, which is distinguished from a downlink allocation DCI format, configuration or indication information for this is explicitly transmitted from a base station to a corresponding UE. Or may be signaled implicitly.

According to an example, whether PUCCH resources are allocated through the PUCCH triggering DCI format may be configured by a base station through UE-specific or cell-specific RRC signaling. In this case, based on configuration information on whether PUCCH resources for HARQ feedback are allocated through a separate PUCCH triggering DCI format, the UE receives PUCCH resource allocation information through a PUCCH resource indicator included in a downlink allocation DCI format. Or, it may be determined whether to receive PUCCH resource allocation information through PUCCH triggering DCI format reception for separate PUCCH resource allocation.

According to another example, the configuration information may be indicated through DCI format 1_0 or DCI format 1_1, which is a downlink allocation DCI format including PDSCH resource allocation information. That is, when allocating resources for the PDSCH, the downlink allocation DCI format may include delay indication information indicating whether to delay the transmission of HARQ feedback information. This means that information on whether PUCCH resource allocation information is made through a PUCCH resource indicator of a downlink allocation DCI format or is delayed through a separate PUCCH triggering DCI format transmitted subsequently is signaled through the corresponding downlink allocation DCI format. Can mean being.

In this case, according to an example, the corresponding DL allocation DCI format may include a separate information area for indicating delay indication information, for example, a PUCCH allocation flag information area. Alternatively, the downlink allocation DCI format may be configured to indicate this by using an existing information area, for example, a PUCCH resource indicator information area.

Alternatively, the information may be implicitly signaled. As an example of this, delay indication information may be indicated according to K1 value indicated through a corresponding downlink allocation DCI format. That is, if the K1 value is greater than or equal to a certain threshold, the PUCCH resource allocation may be indicated through a separate PUCCH triggering DCI format. Alternatively, when the K1 value is smaller than the corresponding threshold value, PUCCH resource allocation may be performed through the PUCCH resource indicator of the corresponding DL allocation DCI format. In this case, the specific threshold may be fixed to a specific value or may be set by cell base station through cell-sepcific / UE-specific RRC signaling.

Referring to FIG. 11 again, the base station may receive HARQ feedback information in the unlicensed band according to the HARQ timing indication information (S1120).

When PUCCH resource allocation is performed through the PUCCH resource indicator of the corresponding DL allocation DCI format, the base station may receive HARQ feedback information according to the received resource allocation information.

In contrast, when a delay for transmission of HARQ feedback information is indicated, that is, when PUCCH resource allocation is indicated through a PUCCH triggering DCI format, the base station transmits resource allocation information and timing information for transmission of HARQ feedback information. Until the transmission of the HARQ feedback information by the terminal may be delayed. After transmitting the downlink allocation DCI format, the base station can transmit the PUCCH triggering DCI format. The base station may receive HARQ feedback information according to resource allocation information and timing information for the uplink control channel included in the PUCCH triggering DCI format. In this case, the base station may receive all HARQ ACK feedback information pending when the PUCCH triggering DCI format is received through the corresponding PUCCH.

Accordingly, a method and apparatus for transmitting HARQ feedback information in an unlicensed band for transmitting HARQ feedback information for reception of a downlink data channel in an unlicensed band can be provided.

Hereinafter, each embodiment of transmitting HARQ feedback information in an unlicensed band in NR will be described in detail with reference to the related drawings.

As described above, in order to transmit a radio signal from any node in the unlicensed band, it is required to go through a List Before Talk (LBT) process to check whether the corresponding radio channel is occupied by another node.

Accordingly, in order to transmit PDSCH for an arbitrary UE in an NR-U cell of an unlicensed band configured by an arbitrary NR base station, the base station must perform LBT for the corresponding unlicensed band. As a result of performing LBT, when the radio channel of the corresponding unlicensed band is empty, the base station may transmit a PDCCH and a corresponding PDSCH to the terminal.

Similarly, in order to transmit an uplink signal in the unlicensed band, the terminal also needs to perform LBT on the unlicensed band before transmitting the uplink signal.

According to an example, in NR, a base station sets RRC signaling or instructs a corresponding terminal through DL assignment DCI (DL assignment DCI) for HARQ ACK / NACK feedback timing for PDSCH reception of a terminal. Can be. However, in the case of the NR-U cell for the aforementioned unlicensed band, PUCCH transmission including HARQ ACK / NACK feedback information may not be possible at the time indicated by the base station according to the LBT result of the terminal. That is, when LBT failure occurs when the corresponding radio channel is occupied by another node as a result of LBT, the UE cannot transmit HARQ ACK / NACK feedback information according to PDSCH at the time indicated by the base station. do. This may cause serious degradation in HARQ performance in the NR-U cell.

12 illustrates an example of performing LBT for wireless communication in an unlicensed band according to an embodiment.

According to an example, when allocating PUCCH transmission resources for an arbitrary terminal, or when allocating PUSCH transmission resources, at a corresponding PUCCH or PUSCH transmission time, the base station may indicate whether to perform LBT on the corresponding terminal. The UE may transmit uplink control information (UCI) such as HARQ ACK / NACK feedback information or CQI / CSI reporting information to the base station through the PUCCH. In this regard, in the NR, time resources and frequency resources, which are PUCCH resources for transmitting HARQ feedback, may be indicated by a base station through a DL assignment DCI. Alternatively, the PUCCH resource for transmitting HARQ feedback may be set to semi-static through RRC signaling. In particular, in the case of time resources, a K1 value, which is a timing gap value between a PDSCH reception slot and a corresponding HARQ feedback information transmission slot, may be transmitted to a terminal through DL assignment DCI or RRC signaling.

PUCCH resources for CQI / CSI reporting may also be allocated through RRC signaling and DL assignment DCI.

Referring to FIG. 12, the LBT (DL LBT) for downlink transmission is successful at the base station, and it is indicated by hatching that the downlink transmission is performed through the unlicensed band at a later point in time. According to an example, the downlink transmission may be a transmission of a downlink channel or a signal indicating uplink transmission. For example, a PUCCH for PDSCH transmission and a corresponding HARQ feedback, a DCI requiring CQI / CSI reporting, a PUCCH for reporting accordingly, or a DCI for transmitting scheduling information for the PUSCH and a corresponding PUSCH, etc. Can be. In this case, a timing gap occurs between downlink transmission and uplink transmission.

For example, when a downlink signal or channel according to downlink transmission indicates PUCCH transmission in an NR-U cell that is an unlicensed band, the UE basically transmits the corresponding PUCCH according to regulation of an unlicensed spectrum. LBT should be preferentially performed and PUCCH transmission at the indicated time is determined according to the LBT result. If, as a result of the LBT, the corresponding radio channel is occupied by another node, that is, when an LBT failure occurs, the corresponding UE may not perform PUCCH transmission at the indicated time.

However, a DLSCH allocation slot including a PUCCH resource allocation information and PUCCH transmission indication information or a PDSCH transmission slot according to a corresponding DL assignment DCI and a corresponding PUCCH transmission slot are corresponding base stations. If the UE belongs to the Channel Occupancy Time (COT) of the UE, PUCCH transmission may be possible in the corresponding UE without performing LBT. This is because the base station is already occupied for downlink transmission to the corresponding UE in the unlicensed band and is not occupied by another node. That is, depending on the setting of the COT and the K1 value of the base station, HARQ feedback transmission through the PUCCH may be possible in the corresponding terminal without LBT.

Similarly, when CSI / CQI reporting through PUCCH is indicated through DL assignment DCI, a slot in which DL assignment DCI is transmitted and CQI / CSI reporting accordingly If a timing gap value between slots in which PUCCH transmission including reporting information is formed is M, CSI / CQI reporting through PUCCH without LBT in the corresponding UE according to the corresponding timing gap value M and the COT of the base station. This may be possible.

In addition, similar to the case of PUCCH, K2 value, which is timing gap information between UL grant DCI transmitted by a base station and a slot in which PUSCH transmission is performed, is also used for PUSCH transmission of a UE. May be set to semi-static through RRC signaling or dynamically through UL grant DCI (UL grant DCI). Even in this case, when an uplink grant DCI (UL grant DCI) transmission slot including the corresponding PUSCH transmission resource allocation information and a corresponding PUSCH transmission slot belong to within a COT (Channel Occupancy Time) of the base station, the corresponding UE does not perform the LBT. Transmission may be possible.

In this regard, according to an embodiment of the present disclosure, the base station may instruct the terminal by setting an LBT scheme for performing LBT when PUCCH or PUSHC transmission from any terminal. According to an example, the LBT scheme may be divided into a plurality of schemes by at least one of whether to perform LBT, random back off, and random back off time. In the present disclosure, a method of performing LBT is referred to as an 'LBT method', but is not limited thereto. The manner of performing the LBT may be variously referred to as the LBT category.

According to an example, the LBT method may include a first LBT method that does not perform LBT, a second LBT method that performs LBT but does not perform random backoff, and performs random backoff with the LBT, but the random backoff time interval is fixed. The third LBT scheme and the random backoff may be performed with the LBT, but the random backoff time interval may include a fourth LBT scheme and the like.

According to an example, the BS may be defined to directly indicate whether to perform LBT for uplink transmission of the UE through L1 control signaling. In more detail, it may be defined to include a corresponding LBT indication information region in a downlink allocation DCI format for transmitting PDSCH scheduling control information.

For example, the LBT indication information may be indication information of 1 bit. In this case, when PUCCH transmission of a terminal corresponding to a corresponding DL assignment DCI format (DL assignment DCI format) is determined according to the value (0, 1) of the corresponding bit, whether or not to perform LBT on the corresponding terminal may be determined. have. That is, in this case, the value of the corresponding bit may mean that the first LBT scheme and the remaining LBT schemes are distinguished from the aforementioned LBT schemes.

According to another example, the corresponding LBT indication information may be two bits of indication information. In this case, when transmitting the PUCCH of the terminal corresponding to the DL assignment DCI format (DL assignment DCI format) according to the value of the corresponding bit (00, 01, 10, 11), the LBT scheme for performing the LBT in the terminal Can be defined to be determined. That is, in this case, the value of the corresponding bit may mean that the first LBT scheme and the fourth LBT scheme are distinguished from the aforementioned LBT scheme.

In this case, the PUCCH transmission of the UE corresponding to the aforementioned DL assignment DCI format may transmit HARQ feedback information of the UE according to the PDSCH reception of the UE based on the corresponding DL assignment DCI format. It may be a PUCCH transmission for. Alternatively, in another case of PUCCH transmission of a UE corresponding to a DL assignment DCI format, CQI / CSI reporting is triggered by a corresponding DL assignment DCI format. ), It may be a PUCCH transmission for CQI / CSI reporting accordingly.

Similarly, it may be defined to include a corresponding LBT indication information region in an uplink grant DCI format (UL grant DCI format) for transmitting PUSCH scheduling control information.

For example, the LBT indication information may be indication information of 1 bit. In this case, according to the value of the corresponding bit (0, 1), when the PUSCH transmission of the terminal corresponding to the UL grant DCI format (UL grant DCI format), it can be defined to determine whether to perform the LBT in the terminal. have. That is, in this case, the value of the corresponding bit may mean distinguishing the first scheme from the remaining schemes among the aforementioned LBT schemes.

According to another example, the corresponding LBT indication information may be two bits of indication information. In this case, when the PUSCH of the UE corresponding to the UL grant DCI format (UL grant DCI format) according to the value (00, 01, 10, 11) of the corresponding bit, the LBT scheme for performing the LBT in the UE Can be defined to be determined. That is, in this case, the value of the corresponding bit may mean that the first to fourth schemes are distinguished from the aforementioned LBT schemes.

However, the PUSCH transmission of the terminal corresponding to the UL grant DCI format may be a PUSCH transmission for uplink data transmission of the terminal or a PUSCH transmission for UCI transmission of the terminal.

As another embodiment of defining whether to perform LBT for the uplink transmission or the LBT scheme in the terminal, whether to perform the corresponding LBT is shown in FIG. 12, downlink transmission indicated by the corresponding uplink transmission and corresponding uplink It may be defined to be determined by a timing gap value between transmissions.

According to an example, when a timing gap value is smaller than a certain threshold value, respectively, the UE may be defined to enable the indicated PUCCH or PUSCH transmission without LBT. Alternatively, when a timing gap value is larger than a corresponding threshold, the UE may define that the corresponding PUCCH or PUSCH transmission is possible after performing LBT.

According to an example, the threshold is determined by the COT value in the corresponding NR-U, or accordingly, cell-specific RRC signaling or UE-specific RRC signaling by the base station. It may be configured through specific RRC signaling or may be configured through cell-specific RRC signaling or UE-specific RRC signaling by the base station regardless of the COT.

In addition, the threshold is defined as a single threshold for each uplink transmission case or as a different threshold for cell-specific RRC signaling by the base station. It may be configured through specific RRC signaling or UE-specific RRC signaling.

Accordingly, the LBT scheme to be performed to transmit the uplink signal in the unlicensed band can be determined, and the uplink signal can be transmitted in the unlicensed band according to the determined LBT scheme.

The present disclosure proposes a HARQ ACK / NACK feedback method of a terminal for an NR-U cell in consideration of a case where an unlicensed band may be occupied by another node at an indicated time point as in the above-described example. In addition, the present disclosure may be substantially applied to a method of transmitting an uplink control channel (PUCCH) including other types of UCI, such as SR or CSI / CQI feedback, in addition to HARQ ACK feedback.

Embodiment 1. Directly indicates HARQ ACK / NACK feedback slot through separate downlink control information (Separate DCI)

According to an example, in addition to downlink data channel (PDSCH) allocation through DL assignment DCI, separate downlink for PUCCH transmission indication including HARQ feedback information of UE for the corresponding PDSCH A link control information format (DCI format) may be defined. Through this, the base station may be defined to trigger a PUCCH transmission including HARQ feedback information for any terminal.

In the existing NR system, a K1 value, which is a resource allocation and feedback timing for an uplink control channel (PUCCH) for HARQ feedback, is indicated through a DL assignment DCI. Alternatively, the corresponding K1 value is set through RRC signaling. However, in the case of the NR-U cell which is an unlicensed band, it may be difficult to ensure the PUCCH transmission of the UE in the slot according to the indicated K1 value. Therefore, according to the present embodiment, the base station checks the accessibility (accessibility) for the corresponding radio channel through the LBT, and informs the terminal when the access (access) is possible, thereby triggering the PUCCH transmission of the terminal (triggering) Can be defined.

PUCCH transmission triggering information may be transmitted through the PDCCH. According to an example, the PUCCH transmission triggering information is UE-group common DCI format (UE-group common DCI format) for the corresponding PUCCH transmission triggering is defined UE-group common PDCCH (ie, UE-group common PDCCH) , Via CSS). Alternatively, the PUCCH transmission triggering information is defined in a UE-specific DCI format (UE-specific DCI format) for the corresponding PUCCH transmission triggering to be transmitted through the UE-specific PDCCH (ie, USS) Can be.

In this case, as shown in FIG. 13, according to an example, the PUCCH triggering DCI format may be defined to include a PUCCH resource allocation information and a K3 value that is PUCCH transmission timing information. Can be. Here, the K3 value may be defined as a timing gap between a reception slot of a corresponding PUCCH triggering DCI format and a corresponding PUCCH transmission slot of a terminal.

Alternatively, as shown in FIG. 14, the PUCCH triggering DCI format includes only PUCCH resource allocation information, and the K3 value is UE-specific / cell-specific higher layer signaling. signaling) may be set by the base station or defined as any fixed value.

Alternatively, as shown in FIG. 15, the PUCCH triggering DCI format includes only a K3 value, and the PUCCH resource allocation information to be transmitted by each UE is included in a DL assignment DCI format. Can be defined to be.

If a PUCCH resource for HARQ feedback of the UE for PDSCH is allocated through a separate PUCCH triggering DCI format, which is distinguished from a DL assignment DCI format, a configuration or indication thereof Information may be signaled (explicitly or implicitly) from the base station to the corresponding terminal (explicitly or implicitly).

According to an example, whether PUCCH resources are allocated through the PUCCH triggering DCI format is determined by a base station through UE-specific or cell-specific RRC signaling. Can be. In this case, through the configuration information, as shown in FIG. 16, the UE receives PUCCH resource allocation information through a PUCCH resource indicator included in a DL assignment DCI format, or is separate. It may be determined whether to receive the PUCCH resource allocation information through the reception of the PUCCH triggering DCI format for PUCCH resource allocation.

According to another example, the configuration information may be indicated through a DCI format 1_0 or DCI format 1_1, which is a DL assignment DCI format including PDSCH resource allocation information. That is, when the corresponding PDSCH resource is allocated, whether PUCCH resource allocation information is made through a PUCCH resource indicator of a DL assignment DCI format or a separate DCI format that is subsequently transmitted, PUCCH Information on whether to perform the PUCCH triggering DCI format may be signaled through a corresponding DL assignment DCI format, in this case, as shown in FIG. 17. The DL assignment DCI format may include a separate information area for indicating this, for example, a PUCCH allocation flag information area, etc. Alternatively, a DL assignment DCI format. May be defined to indicate an existing information area, for example, by using a PUCCH resource indicator information area. The location of each information in the DCI formats is arbitrarily shown and is not limited to that location.

Alternatively, the information may be implicitly signaled. As an example of this, the corresponding information may be indicated according to the K1 value indicated through the corresponding DL assignment DCI format. That is, if the K1 value is greater than or equal to a certain threshold, PUCCH resource allocation may be indicated through a separate DCI format. In addition, when the K1 value is smaller than a corresponding threshold, PUCCH resource allocation may be performed through a PUCCH resource indicator of a corresponding DL assignment DCI format. In this case, the specific threshold may be fixed to a specific value or may be set by cell base station through cell-sepcific / UE-specific RRC signaling.

When a UE receives the PUCCH triggering DCI format, the UE may define to transmit all pending HARQ ACK feedback information through the corresponding PUCCH accordingly.

Accordingly, a method and apparatus for transmitting HARQ feedback information in an unlicensed band that can transmit HARQ feedback information for reception of a downlink data channel in an unlicensed band can be provided.

According to an embodiment, until any UE receives a PUCCH triggering DCI format, if any other UCI such as CQI / CSI reporting or SR other than HARQ feedback exists, all pending UCIs (pending) UCI) may be defined to be transmitted through the PUCCH.

However, a maximum payload size or a maximum codebook size that can be transmitted through an arbitrary PUCCH is set by the base station so that UE-specific / cell-specific higher layer It may be transmitted to the terminal through higher layer signaling, MAC CE signaling, or L1 control signaling. In this case, when the UE transmits the PUCCH according to the reception of the PUCCH triggering DCI format, when the payload size of the pending UCI exceeds the maximum payload size, the UE transmits a specific UCI. Can be defined to drop.

In this case, a priority rule for UCI dropping may be defined. As an example of this, priority may be defined for each UCI type. As an example of defining the priority for each UCI type, priority may be defined in the order of SR> HARQ ACK feedback> CQI / CSI reporting. Alternatively, priority may be defined in order of SR = HARQ ACK feedback> CQI / CSI reporting. However, this is merely an example and the present invention is not limited thereto. All cases of defining priorities for each other UCI type may be included in the scope of the present disclosure. In addition, when dropping occurs among UCIs of the same priority or the same type, the dropping is performed in order of the most recent UCI, or in the order of the oldest UCI. can do.

Accordingly, a specific method and apparatus for transmitting an uplink control channel (PUCCH) including various uplink control information in an unlicensed band can be provided.

Example 2 HARQ Feedback Window Setting

According to an example, the HARQ feedback window may be set to a continuous HARQ feedback window.

In order to secure reliability for HARQ ACK / NACK feedback transmission of the UE in the NR-U cell, a plurality of PUCCH resource sets for transmitting HARQ feedback for one PDSCH reception may be defined. Each PUCCH resource constituting the plurality of PUCCH resource sets corresponding to one PDSCH reception is referred to as a PUCCH opportunity in the present disclosure. However, this is merely an example and is not limited to the term.

Specifically, a plurality of PUCCH opportunities for HARQ feedback of a UE according to one PDSCH reception may be configured in a time domain. Referring to FIG. 18, the HARQ feedback window may consist of consecutive slots. Accordingly, the base station may transmit the offset value and the corresponding window size information, which are the start slot of the corresponding HARQ feedback window, to the terminal. Here, the offset value means a K1 value that is a timing gap between the PDSCH reception slot of the UE and the slot where the HARQ feedback window starts. The window size value means an N value that is the number of consecutive slots in which PUCCH opportunities are configured from the start slot of the HARQ feedback window by the K1 value.

As an example of transmitting the K1 and the N value to the UE, the K1 and N values may be indicated through separate information areas. In this case, the corresponding K1 value is indicated through DL assignment DCI and N value is semi-static through UE-specific or cell-specific higher layer signaling. It can be set to (semi-static). Alternatively, both the K1 value and the N value may be set to semi-static through UE-specific or cell-specific higher layer signaling. Alternatively, both the K1 value and the N value may be dynamically indicated through DL assignment DCI. Alternatively, the K1 value is set to semi-static through UE-specific or cell-specific higher layer signaling, and the N value is DL allocated DCI (DL). It may be indicated dynamically through an assignment DCI).

However, when a K1 value or N value is indicated through a DL assignment DCI, a table for mapping between the setting value according to the indication information and the actual K1 value or N value accordingly. ) May be configured through UE-specific or cell-specific RRC signaling. That is, when the K1 value is defined to be indicated through the DL assignment DCI, the actual K1 corresponding to each setting value of the K1 indication information region transmitted through the DL assignment DCI format. A mapping table defining values may be configured through UE-specific or cell-specific RRC signaling. Similarly, when the N value is defined to be indicated through DL assignment DCI, the actual value corresponding to the setting value of the corresponding N indication information region transmitted through DL assignment DCI format is applied. A mapping table defining an N value may be configured through UE-specific or cell-specific RRC signaling.

As another example of transmitting the K1 and the N value to the UE, one information area for deriving the corresponding N value and the K1 value, for example, an HARQ window configuration information area is defined and corresponding N It can be defined to set value and K1 value. That is, the N value and the K1 value may be defined according to the HARQ window configuration setting value. In this case, the corresponding HARQ window configuration information is set to semi-static through UE-specific or cell-specific higher layer signaling, or downlink allocation DCI It may be set dynamically through (DL assignment DCI).

Specifically, a mapping table defining a corresponding N value and K1 value for each HARQ window configuration setting value is defined, and based on this, the corresponding HARQ window configuration information is UE-specific or cell-specific higher layer. It may be semi-statically configured through signaling or may be dynamically configured through DL assignment DCI. However, when the corresponding HARQ window configuration information is set dynamically through the DL assignment DCI or DL assignment DCI, the HARQ window configuration indication information region transmitted through the downlink assignment DCI. A mapping table defining actual N values and K1 values corresponding to the set values may be configured by the base station through UE-specific or cell-specific RRC signaling. have.

According to another example, the HARQ feedback window may be set to a discontinuous HARQ feedback window.

Referring to FIG. 19, the HARQ feedback window may be composed of noncontiguous slots. Accordingly, the base station transmits the number of PUCCH opportunities information, which is the start slot of the corresponding HARQ feedback window, that is, period information of the offset value, PUCCH opportunity and window size information, to the terminal. Can be. The offset value means a K1 value that is a timing gap between the PDSCH reception slot of the UE and the slot where the HARQ feedback window starts. The window size value means the number of non-contiguous slots in which PUCCH opportunities are configured from the start slot of the HARQ feedback window according to the K1 value, and the N value. The PUCCH opportunity period information means a P value, which is an interval between slots in which each PUCCH opportunity is configured in a corresponding HARQ feedback window.

As an example of transmitting the K1, the N value, and the P value to the terminal, separate information areas for indicating the K1 value, the N value, and the P value may be defined. As described above, when the information areas for indicating the K1 value, the N value, and the P value are respectively defined, a specific method for transmitting the corresponding K1 value, the N value, and the P value to the terminal includes transmitting the aforementioned K1 value and the N value to the terminal. The content described in the example of defining each information area for transmission may be applied in the same manner, and redundant descriptions will be omitted.

Similarly, as another example for transmitting the K1 value, the N value, and the P value to the terminal, an information area for deriving the corresponding K1 value, the N value, and the P value, for example, an HARQ window configuration information area is defined. And it can be defined to set the corresponding K1 value, N value, and P value. A specific HARQ window configuration information area transmission method and a method of setting the K1 value, the N value, and the P value according to this method define a HARQ window configuration information area in order to set the above-described N value and K1 value, and through this, the corresponding N value. The methods described in the example of defining to set the value and K1 may be applied in the same manner, and redundant descriptions thereof will be omitted.

Alternatively, one information area for indicating the K1 value is defined, and another information area for setting the N value and the P value is defined, and the corresponding K1 value, the N value, and the P value are transmitted to the terminal. Can be defined to That is, an offset indication information area for transmitting an offset K1 value is defined, and another information area for setting an N value and a P value, for example, an HARQ window configuration information area is separately defined. Through this, N and P values can be defined. In this case, a specific method of transmitting the offset indication information region for indicating the corresponding K1 value and the HARQ window configuration information region for setting the N value and the P value to the terminal includes the aforementioned two methods, K1 value and N value to the terminal. In the method described in the example of defining each information area for transmission, and in the example of defining one HARQ window configuration information area to set the N value and the K1 value, and setting the corresponding N value and the K1 value through this, All combinations of the described methods can be applied, and overlapping descriptions will be omitted.

In addition, when the above-described HARQ feedback window configuration method is applied, each PUCCH opportunity of the corresponding HARQ feedback window may be configured with the same PUCCH resource. That is, PUCCH resources corresponding to each PUCCH opportunity may be defined to be allocated to the same PUCCH format and the same frequency resource. In this case, the PUCCH resources constituting the PUCCH opportunity constituting the corresponding HARQ feedback window may be assigned DL downlink DCI (DL assignment DCI) according to the PUCCH resource mapping rule defined by the TS 38.213 document. It can be defined to share the PUCCH resources by the PUCCH resource allocation information indicated through.

As another example, the PUCCH resources constituting each PUCCH opportunity may be PUCCH resources configured through different sub-bands or bandwidth parts (BWPs). That is, frequency hopping may be applied to PUCCH resources constituting each PUCCH opportunity of the corresponding HARQ feedback window, and frequency hopping may be performed in subband units or bandwidth parts. (BWP) units.

As such, when frequency hopping is defined for each PUCCH opportunity within the HARQ feedback window for a certain UE, the frequency hopping is activated or deactivated by the base station. The activation / deisabling indication information may be set by the base station to allow UE-specific / cell-specific RRC signaling or DL assignment DCI. Or it may be transmitted to the terminal through the MAC CE signaling (signaling).

In addition, a sub-band or bandwidth part (BWP) for applying frequency hopping to PUCCH opportunity of the corresponding HARQ feedback window may include a UL (or DL) bandwidth part configured for the UE. It may be set separately from the BWP) and transmitted to the terminal through UE-specific / cell-specific RRC signaling. Alternatively, a sub-band or bandwidth part (BWP) for applying frequency hopping to PUCCH opportunity in the corresponding HARQ feedback window may include a UL (or DL) bandwidth part (BWP) configured for the UE. ) Can be defined to follow.

Accordingly, when frequency hopping for PUCCH opportunity is defined and applied, the PUCCH resources constituting each PUCCH opportunity are each subband that is a unit of hopping. DL assignment DCI according to PUCCH resource mapping rule defined by document TS 38.213 for PUCCH resource sets defined in band or bandwidth part (BWP) The PUCCH resource allocation can be defined according to the ARI indicated through.

In this case, the sub-band or bandwidth part (BWP) hopping pattern is a constant pattern according to the number of sub-bands or bandwidth parts (BWP) set for the corresponding UE. Is defined, or is semi-statically configured by the base station through UE-specific / cell-specific higher layer signaling, or the downlink allocation DCI format ( It may be indicated dynamically through a DL assignment DCI format. However, when a corresponding hopping pattern is dynamically indicated through a DL assignment DCI format, a subband for each setting value of the corresponding hopping pattern indication information region may be used. A band or bandwidth part hopping pattern table may be configured by a base station and configured through UE-specific / cell-specific higher layer signaling.

Or, a hopping size for a corresponding PUCCH opportunity hopping is directly set by a base station so that UE-specific / cell-specific RRC signaling or MAC CE signaling is performed. (signalling) or DL assignment DCI (DL assignment DCI) may be defined to be transmitted directly to the terminal. The hopping size may be set in units of PRBs. In this case, frequency hopping may be applied to the PUCCH resources constituting each PUCCH opportunity according to the set hopping size. In this case, the frequency hopping may be configured. It may be defined within the bandwidth part (BWP) or within the system bandwidth of the carrier.

In addition, the frequency hopping may be applied in units of one PUCCH opportunity, that is, every PUCCH opportunity, or may be applied in units of a group of PUCCH opportunities. That is, if any HARQ feedback window consists of N PUCCH opportunities, frequency hopping is applied for each PUCCH opportunity, or successive M (N <N) PUCCH opportunities The above frequency hopping may be applied in units of opportunities. In this case, the corresponding M value is also set by the base station through UE-specific / cell-specific RRC signaling or MAC CE signaling or DL assignment DCI. It may be defined to be transmitted to the terminal.

Additionally, when a HARQ feedback window is configured for any UE in any NR-U cell, the UEs may be defined to basically perform LBT for PUCCH transmission at each PUCCH opportunity. However, when only a single PUCCH opportunity (opportunity), which is the case where the N value, which is a size value of the HARQ feedback window, is set to 1, the terminal is defined to transmit the PUCCH through the corresponding PUCCH opportunity without LBT. can do.

Accordingly, a method and apparatus for transmitting HARQ feedback information in an unlicensed band that can transmit HARQ feedback information for reception of a downlink data channel in an unlicensed band can be provided.

Hereinafter, configurations of a terminal and a base station capable of performing some or all of the embodiments described with reference to FIGS. 1 to 19 will be described with reference to the drawings.

20 is a diagram illustrating a configuration of a user terminal 2000 according to another embodiment.

Referring to FIG. 20, the user terminal 2000 according to another embodiment includes a controller 2010, a transmitter 2020, and a receiver 2030.

The controller 2010 controls the overall operation of the user terminal 2000 according to the method for transmitting HARQ feedback information in the unlicensed band required to perform the above-described present disclosure. The transmitter 2020 transmits uplink control information, data, and a message to a base station through a corresponding channel. The receiver 2030 receives downlink control information, data, and a message from a base station through a corresponding channel.

According to an example, the receiver 2030 may receive downlink control information including resource allocation information for a downlink data channel (PDSCH) in an unlicensed band.

The receiver 2030 may receive a downlink data channel from the base station based on resource allocation information included in the downlink control information. The transmitter 2020 may transmit HARQ ACK / NACK feedback information to the base station as to whether to receive the downlink data channel.

The receiver 2030 may receive HARQ timing indication information for transmitting HARQ feedback information in the unlicensed band.

In the NR system, the receiver 2030 may receive a resource allocation and feedback timing K1 value for an uplink control channel (PUCCH) for HARQ feedback through a DL assignment DCI. Alternatively, the feedback timing K1 value may be set through RRC signaling. The transmitter 2020 may transmit HARQ feedback information based on whether a downlink data channel is received based on the received resource allocation and K1 value of feedback timing.

However, when using the unlicensed band, when the corresponding unlicensed band is occupied by another node in the slot according to the K1 value indicated by the base station, the transmitter 2020 may be difficult to transmit the PUCCH at the indicated timing. Therefore, according to an example, when the base station performs an access to the unlicensed band by performing List Before Talk (LBT), the terminal may be notified of this to trigger the PUCCH transmission of the transmitter 2020.

According to an example, the PUCCH transmission triggering information may be defined through a UE-group common DCI format (UE-group common DCI format) for the corresponding PUCCH transmission triggering and transmitted through the UE-group common PDCCH. . Alternatively, the PUCCH transmission triggering information may be defined through a UE-specific DCI format (UE-specific DCI format) for the corresponding PUCCH transmission triggering may be transmitted through the UE-specific PDCCH (UE-specific PDCCH).

According to an example, the PUCCH triggering DCI format set separately may include resource allocation information for the PUCCH and a K3 value that is PUCCH transmission timing information. Here, the K3 value may be set as a timing gap between a reception slot of a corresponding PUCCH triggering DCI format and a PUCCH transmission slot of a terminal accordingly.

Alternatively, according to another example, the PUCCH triggering DCI format includes only PUCCH resource allocation information, and the K3 value is set by the base station through UE-specific / cell-specific higher layer signaling. Can be. Alternatively, the K3 value can be set to any fixed value.

Alternatively, according to another example, the PUCCH triggering DCI format may be set to include only a K3 value. In this case, the PUCCH resource allocation information to be transmitted by each terminal may be configured to be included in a DL assignment DCI format.

When a PUCCH resource for HARQ feedback of a UE for a PDSCH is allocated through a separate PUCCH triggering DCI format, which is distinguished from a downlink allocation DCI format, configuration or indication information for this is explicitly transmitted from a base station to a corresponding UE. Or may be signaled implicitly.

According to an example, whether PUCCH resources are allocated through the PUCCH triggering DCI format may be configured by a base station through UE-specific or cell-specific RRC signaling. In this case, based on configuration information on whether PUCCH resources for HARQ feedback are allocated through a separate PUCCH triggering DCI format, the controller 2010 allocates PUCCH resources through a PUCCH resource indicator included in a downlink allocation DCI format. It may be determined whether to receive the information, or whether to receive the PUCCH resource allocation information through the PUCCH triggering DCI format reception for separate PUCCH resource allocation.

According to another example, the configuration information may be indicated through DCI format 1_0 or DCI format 1_1, which is a downlink allocation DCI format including PDSCH resource allocation information. That is, when allocating resources for the PDSCH, the downlink allocation DCI format may include delay indication information indicating whether to delay the transmission of HARQ feedback information. This means that information on whether PUCCH resource allocation information is made through a PUCCH resource indicator of a downlink allocation DCI format or is delayed through a separate PUCCH triggering DCI format transmitted subsequently is signaled through the corresponding downlink allocation DCI format. Can mean being.

In this case, according to an example, the corresponding DL allocation DCI format may include a separate information area for indicating delay indication information, for example, a PUCCH allocation flag information area. Alternatively, the downlink allocation DCI format may be configured to indicate this by using an existing information area, for example, a PUCCH resource indicator information area.

Alternatively, the information may be implicitly signaled. As an example of this, delay indication information may be indicated according to K1 value indicated through a corresponding downlink allocation DCI format. That is, if the K1 value is greater than or equal to a certain threshold, the PUCCH resource allocation may be indicated through a separate PUCCH triggering DCI format. Alternatively, when the K1 value is smaller than the corresponding threshold value, PUCCH resource allocation may be performed through the PUCCH resource indicator of the corresponding DL allocation DCI format. In this case, the specific threshold may be fixed to a specific value or may be set by cell base station through cell-sepcific / UE-specific RRC signaling.

The transmitter 2020 may transmit HARQ feedback information in the unlicensed band according to the HARQ timing indication information.

When PUCCH resource allocation is made through the PUCCH resource indicator of the corresponding DL allocation DCI format, the transmitter 2020 may transmit HARQ feedback information according to the received resource allocation information.

In contrast, when a delay for the transmission of the HARQ feedback information is indicated, that is, when the PUCCH resource allocation is indicated through the PUCCH triggering DCI format, the controller 2010 allocates resource allocation information for transmitting HARQ feedback information from the base station. And delaying transmission of HARQ feedback information until receiving timing information. The receiver 2030 may receive the PUCCH triggering DCI format after the downlink allocation DCI format is received. The transmitter 2020 may transmit HARQ feedback information according to resource allocation information and timing information for the uplink control channel included in the PUCCH triggering DCI format. In this case, the transmitter 2020 may transmit all HARQ ACK feedback information pending when the PUCCH triggering DCI format is received through the corresponding PUCCH.

Accordingly, a method and apparatus for transmitting HARQ feedback information in an unlicensed band for transmitting HARQ feedback information for reception of a downlink data channel in an unlicensed band can be provided.

In the above description, a case in which HARQ feedback information is transmitted as UL control information (UCI) is described, but the present invention is not limited thereto. According to an embodiment of the present disclosure, if there is other UCI such as CQI / CSI reporting or SR other than HARQ feedback before the PUCCH triggering DCI format is received, the transmitter 2020 may transmit all UCIs that are pending. Can be transmitted through the corresponding PUCCH.

However, a maximum payload size or a maximum codebook size that can be transmitted through any PUCCH may be set by the base station. In addition, the configured maximum payload size or maximum codebook size may be UE-specific / cell-specific higher layer signaling, MAC CE signaling, or L1 control signaling. ) May be transmitted to the terminal. In this case, the controller 2010 drops a specific UCI when the payload size of the pending UCI exceeds the maximum payload size when the PUCCH is transmitted according to the PUCCH triggering DCI format reception. can be set to dropping.

According to an example, a priority rule for UCI dropping may be set. For example, priority may be set for each UCI type. As an example of defining the priority for each UCI type, priority may be defined in the order of SR> HARQ ACK feedback> CQI / CSI reporting. Alternatively, priority may be defined in order of SR = HARQ ACK feedback> CQI / CSI reporting. However, this is merely an example and the present invention is not limited thereto. All cases of defining priorities for each other UCI type may be included in the scope of the present disclosure. In addition, when dropping occurs among UCIs of the same priority or the same type, the dropping is performed in order of the most recent UCI, or in the order of the oldest UCI. can do.

Accordingly, a specific method and apparatus for transmitting an uplink control channel (PUCCH) including various uplink control information in an unlicensed band can be provided.

21 is a diagram illustrating a configuration of a base station 2100 according to another embodiment.

Referring to FIG. 21, a base station 2100 according to another embodiment includes a controller 2110, a transmitter 2120, and a receiver 2130.

The controller 2110 controls the overall operation of the base station 2100 according to the method for transmitting HARQ feedback information in the unlicensed band required to perform the above-described present disclosure. The transmitter 2120 and the receiver 2130 are used to transmit and receive signals, messages, and data necessary for carrying out the above-described present disclosure with the terminal.

According to an example, the transmitter 2120 may transmit downlink control information including resource allocation information for a downlink data channel (PDSCH) to the terminal in the unlicensed band.

The transmitter 2120 may transmit a downlink data channel to the terminal based on resource allocation information included in the downlink control information. The receiver 2130 may receive HARQ ACK / NACK feedback information from the terminal as to whether to receive the downlink data channel.

The transmitter 2120 may transmit HARQ timing indication information for receiving HARQ feedback information in the unlicensed band.

In the NR system, the transmitter 2120 may transmit a resource allocation and feedback timing K1 value for an uplink control channel (PUCCH) for HARQ feedback through a DL assignment DCI. Alternatively, the feedback timing K1 value may be set through RRC signaling. The receiver 2130 may receive HARQ feedback information according to whether a downlink data channel is received based on the transmitted resource allocation and the feedback timing K1 value.

However, when using the unlicensed band, when the corresponding unlicensed band is occupied by another node in the slot according to the K1 value indicated by the base station, it may be difficult for the terminal to transmit the PUCCH at the indicated timing. Therefore, according to an example, when the base station performs the LBT (Listen Before Talk) to access the unlicensed band, the UE may be notified of this, thereby triggering the PUCCH transmission of the UE.

According to an example, the PUCCH transmission triggering information may be defined through a UE-group common DCI format (UE-group common DCI format) for the corresponding PUCCH transmission triggering and transmitted through the UE-group common PDCCH. . Alternatively, the PUCCH transmission triggering information may be defined through a UE-specific DCI format (UE-specific DCI format) for the corresponding PUCCH transmission triggering may be transmitted through the UE-specific PDCCH (UE-specific PDCCH).

According to an example, the PUCCH triggering DCI format set separately may include resource allocation information for the PUCCH and a K3 value that is PUCCH transmission timing information. Here, the K3 value may be set as a timing gap between a reception slot of a corresponding PUCCH triggering DCI format and a PUCCH transmission slot of a terminal accordingly.

Alternatively, according to another example, the PUCCH triggering DCI format includes only PUCCH resource allocation information, and the K3 value is set by the base station through UE-specific / cell-specific higher layer signaling. Can be. Alternatively, the K3 value can be set to any fixed value.

Alternatively, according to another example, the PUCCH triggering DCI format may be set to include only a K3 value. In this case, the PUCCH resource allocation information to be transmitted by each terminal may be configured to be included in a DL assignment DCI format.

When a PUCCH resource for HARQ feedback of a UE for a PDSCH is allocated through a separate PUCCH triggering DCI format, which is distinguished from a downlink allocation DCI format, configuration or indication information for this is explicitly transmitted from a base station to a corresponding UE. Or may be signaled implicitly.

According to an example, whether PUCCH resources are allocated through the PUCCH triggering DCI format may be configured by a base station through UE-specific or cell-specific RRC signaling. In this case, based on configuration information on whether PUCCH resources for HARQ feedback are allocated through a separate PUCCH triggering DCI format, the controller 2010 allocates PUCCH resources through a PUCCH resource indicator included in a downlink allocation DCI format. It may be determined whether to receive the information, or whether to receive the PUCCH resource allocation information through the PUCCH triggering DCI format reception for separate PUCCH resource allocation.

According to another example, the configuration information may be indicated through DCI format 1_0 or DCI format 1_1, which is a downlink allocation DCI format including PDSCH resource allocation information. That is, when allocating resources for the PDSCH, the downlink allocation DCI format may include delay indication information indicating whether to delay the transmission of HARQ feedback information. This means that information on whether PUCCH resource allocation information is made through a PUCCH resource indicator of a downlink allocation DCI format or is delayed through a separate PUCCH triggering DCI format transmitted subsequently is signaled through the corresponding downlink allocation DCI format. Can mean being.

In this case, according to an example, the corresponding DL allocation DCI format may include a separate information area for indicating delay indication information, for example, a PUCCH allocation flag information area. Alternatively, the downlink allocation DCI format may be configured to indicate this by using an existing information area, for example, a PUCCH resource indicator information area.

Alternatively, the information may be implicitly signaled. As an example of this, delay indication information may be indicated according to K1 value indicated through a corresponding downlink allocation DCI format. That is, if the K1 value is greater than or equal to a certain threshold, the PUCCH resource allocation may be indicated through a separate PUCCH triggering DCI format. Alternatively, when the K1 value is smaller than the corresponding threshold value, PUCCH resource allocation may be performed through the PUCCH resource indicator of the corresponding DL allocation DCI format. In this case, the specific threshold may be fixed to a specific value or may be set by cell base station through cell-sepcific / UE-specific RRC signaling.

The receiver 2130 may receive HARQ feedback information in the unlicensed band according to the HARQ timing indication information.

When PUCCH resource allocation is made through the PUCCH resource indicator of the corresponding DL allocation DCI format, the receiver 2130 may receive HARQ feedback information according to the transmitted resource allocation information.

In contrast, when a delay for transmission of HARQ feedback information is indicated, that is, when PUCCH resource allocation is indicated through a PUCCH triggering DCI format, the UE allocates resource allocation information for transmission of HARQ feedback information from the transmitter 2120. And delaying transmission of HARQ feedback information until receiving timing information. After transmitting the downlink allocation DCI format, the transmitter 2120 may transmit the PUCCH triggering DCI format. The receiver 2130 may receive HARQ feedback information according to resource allocation information and timing information for the uplink control channel included in the PUCCH triggering DCI format. In this case, the receiver 2130 may receive all HARQ ACK feedback information pending when the PUCCH triggering DCI format is received through the corresponding PUCCH.

Accordingly, a method and apparatus for transmitting HARQ feedback information in an unlicensed band for transmitting HARQ feedback information for reception of a downlink data channel in an unlicensed band can be provided.

The above-described embodiments may be supported by standard documents disclosed in at least one of the wireless access systems IEEE 802, 3GPP and 3GPP2. That is, steps, components, and parts which are not described in order to clearly reveal the present technical spirit of the embodiments may be supported by the aforementioned standard documents. In addition, all terms disclosed herein may be described by the standard documents disclosed above.

The above-described embodiments may be implemented through various means. For example, the embodiments may be implemented by hardware, firmware, software, or a combination thereof.

In the case of a hardware implementation, the method according to the embodiments may include one or more Application Specific Integrated Circuits (ASICs), Digital Signal Processors (DSPs), Digital Signal Processing Devices (DSPDs), Programmable Logic Devices (PLDs), FPGAs. (Field Programmable Gate Arrays), a processor, a controller, a microcontroller or a microprocessor may be implemented.

In the case of an implementation by firmware or software, the method according to the embodiments may be implemented in the form of an apparatus, procedure, or function for performing the functions or operations described above. The software code may be stored in a memory unit and driven by a processor. The memory unit may be located inside or outside the processor, and may exchange data with the processor by various known means.

In addition, the terms "system", "processor", "controller", "component", "module", "interface", "model", or "unit" described above generally refer to computer-related entity hardware, hardware and software. Can mean a combination of, software or running software. For example, the aforementioned components may be, but are not limited to, a process driven by a processor, a processor, a controller, a control processor, an object, an execution thread, a program, and / or a computer. For example, both an application running on a controller or processor and a controller or processor can be components. One or more components may be within a process and / or thread of execution, and the components may be located on one device (eg, system, computing device, etc.) or distributed across two or more devices.

The above description is merely illustrative of the technical idea of the present disclosure, and various modifications and variations may be made by those skilled in the art without departing from the essential characteristics of the present disclosure. In addition, the present embodiments are not intended to limit the technical spirit of the present disclosure but to describe the scope of the present inventive concept. The protection scope of the present disclosure should be interpreted by the following claims, and all technical ideas within the scope equivalent thereto shall be interpreted as being included in the scope of the present disclosure.

CROSS-REFERENCE TO RELATED APPLICATION

This patent application is filed with a patent application No. 10-2018-0056288 filed in Korea on May 17, 2018 and a patent application No. 10-2018-0150160 filed in Korea on 28 November 2018 and May 2019. Patent Application No. 10-2019-0055567, filed with Korea on 13th, claims priority under US Patent Act Article 119 (a) (35 USC § 119 (a)), all of which are hereby incorporated by reference. Incorporated into the application. In addition, if this patent application claims priority for the same reason for countries other than the United States, all its contents are incorporated into this patent application by reference.

Claims (15)

1. In the method for the terminal to transmit HARQ feedback information in the unlicensed band,

   Receiving downlink control information including resource allocation information for a downlink data channel (PDSCH) in an unlicensed band;

   Receiving HARQ timing indication information for transmitting HARQ feedback information in the unlicensed band; And

   And transmitting the HARQ feedback information in the unlicensed band according to the HARQ timing indication information.
2. The method of claim 1,

   The downlink control information,

   And delay indication information indicating whether there is a delay for the transmission of the HARQ feedback information.
3. The method of claim 2,

   The delay indication information,

   The method is determined based on the HARQ timing indication information included in the downlink control information.
4. The method of claim 2,

   Transmitting the HARQ feedback information,

   When the delay for the transmission of the HARQ feedback information is indicated, the HARQ feedback information according to resource allocation information for uplink control channels included in different downlink control information received after the downlink control information is received. How to transfer.
5. The method of claim 1,

   The HARQ timing indication information,

   Or included in the downlink control information or in different downlink control information received after the downlink control information is received.
6. In the method for the base station to receive HARQ feedback information in the unlicensed band,

   Transmitting downlink control information including resource allocation information for a downlink data channel (PDSCH) in an unlicensed band;

   Transmitting HARQ timing indication information for transmitting HARQ feedback information in the unlicensed band; And

   And receiving the HARQ feedback information in the unlicensed band according to the HARQ timing indication information.
7. The method of claim 6,

   The downlink control information,

   And delay indication information indicating whether there is a delay for the transmission of the HARQ feedback information.
8. The method of claim 7, wherein

   The delay indication information,

   The method is determined based on the HARQ timing indication information included in the downlink control information.
9. The method of claim 7, wherein

   Receiving the HARQ feedback information,

   When the delay for the transmission of the HARQ feedback information is indicated, the HARQ feedback information according to resource allocation information for uplink control channels included in different downlink control information transmitted after the downlink control information is transmitted. How to receive it.
10. The method of claim 6,

    The HARQ timing indication information,

    Or included in the downlink control information or in different downlink control information transmitted after the downlink control information is transmitted.
11. A terminal for transmitting HARQ feedback information in an unlicensed band,

    A receiver which receives downlink control information including resource allocation information for a downlink data channel (PDSCH) in an unlicensed band and receives HARQ timing indication information for transmitting HARQ feedback information in the unlicensed band; And

    And a transmitter for transmitting the HARQ feedback information in the unlicensed band according to the HARQ timing indication information.
12. The method of claim 11,

    The downlink control information,

    Terminal including delay indication information indicating whether or not to delay the transmission of the HARQ feedback information.
13. The method of claim 12,

    The delay indication information,

    The terminal is determined based on the HARQ timing indication information included in the downlink control information.
14. The method of claim 12,

    The transmitting unit,

    When the delay for the transmission of the HARQ feedback information is indicated, the HARQ feedback information according to resource allocation information for uplink control channels included in different downlink control information received after the downlink control information is received. Terminal for transmitting.
15. The method of claim 11,

    The HARQ timing indication information,

    Terminal included in the downlink control information, or different downlink control information received after the downlink control information is received.

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