KR20230130590A - Method and apparatus for transmitting signal in unlicensed band communication system, method and apparatus for uplink scheduling, and method and apparatus for transmitting information about channel status measurement period - Google Patents

Abstract

An embodiment of the present disclosure provides a method for a terminal to transmit an uplink signal in an unlicensed band, comprising: receiving downlink control information (DCI) in a downlink subframe from a base station; A process of determining a sounding reference signal (SRS) transmission location based on the DCI; and transmitting a plurality of uplink subframes including the SRS according to the SRS transmission location, wherein the SRS is transmitted in the front part of the plurality of uplink subframes and the back part of the plurality of uplink subframes. Included.

Description

A method and device for transmitting signals in an unlicensed band communication system, an uplink scheduling method and device, and a method and device for transmitting information about a channel state measurement section {METHOD AND APPARATUS FOR TRANSMITTING SIGNAL IN UNLICENSED BAND COMMUNICATION SYSTEM, METHOD AND APPARATUS FOR UPLINK SCHEDULING, AND METHOD AND APPARATUS FOR TRANSMITTING INFORMATION ABOUT CHANNEL STATUS MEASUREMENT PERIOD}

The present invention relates to a method and device for configuring and transmitting a signal through time division duplex (TDD) in an unlicensed band wireless communication system.

The present invention also relates to an uplink scheduling method and device.

The present invention also relates to a method and device for transmitting information about a channel state measurement section.

With the advancement of information and communication technology, various wireless communication technologies are being developed. Depending on the band used, wireless communication technology can be broadly classified into wireless communication technology using a licensed band, wireless communication technology using an unlicensed band (e.g., ISM (industrial scientific medical) band), etc. there is. Since the right to use a licensed band is given exclusively to one operator, wireless communication technology using a licensed band can provide better reliability and communication quality than wireless communication technology using an unlicensed band.

Representative wireless communication technologies that use licensed bands include long term evolution (LTE), which is defined in the 3rd generation partnership project (3GPP) standard. Each base station (NodeB, NB) and user equipment (UE) that supports LTE can transmit and receive signals through a licensed band.

Representative wireless communication technologies that use unlicensed bands include WLAN (wireless local area network) specified in the IEEE (Institute of Electrical and Electronics Engineers) 802.11 standard. Each of an access point (AP) and station (STA) that supports WLAN can transmit and receive signals through an unlicensed band.

Meanwhile, mobile traffic has recently grown explosively, and it is necessary to secure additional licensed bands to process this mobile traffic through licensed bands. However, the licensed band is finite and usually the licensed band can be secured through frequency band auctions between operators, etc., so astronomical costs can be incurred to secure additional licensed bands. To solve this problem, providing LTE services through unlicensed bands may be considered.

Cells in unlicensed bands have different characteristics from cells in existing licensed bands. Unlicensed band cells opportunistically occupy channels and cannot continuously occupy channels for more than a certain period of time. Therefore, in order to use the uplink and downlink of an unlicensed band cell in a time-sharing manner, channel access procedures, frame configuration methods, scheduling methods, and methods for transmitting uplink and downlink response messages need to be defined.

Meanwhile, the background technology of the invention was prepared to improve understanding of the background of the invention, and may include content that is not prior art already known to those skilled in the art in the technical field to which the present invention belongs.

The problem to be solved by the present invention is to provide a method and device for configuring and transmitting a signal through time division (TDD) in an unlicensed band wireless communication system.

An embodiment of the present disclosure provides a method for a terminal to transmit an uplink signal in an unlicensed band, comprising: receiving downlink control information (DCI) in a downlink subframe from a base station; A process of determining a sounding reference signal (SRS) transmission location based on the DCI; and transmitting a plurality of uplink subframes including the SRS according to the SRS transmission location, wherein the SRS is transmitted in the front part of the plurality of uplink subframes and the back part of the plurality of uplink subframes. Included.

An embodiment of the present disclosure provides a device for transmitting an uplink signal in an unlicensed band, comprising: a memory including instructions; and receiving downlink control information (DCI) in a downlink subframe from a base station by executing the command, determining a sounding reference signal (SRS) transmission location based on the DCI, and determining the SRS transmission location according to the SRS transmission location. and a processor that transmits a plurality of uplink subframes, wherein the SRS is included in a front part of the plurality of uplink subframes and a rear part of the plurality of uplink subframes.

According to an embodiment of the present invention, it is possible to configure and transmit a signal in a time division (TDD) manner in an unlicensed band.

1, 2, 3, and 4 are diagrams showing an embodiment of a wireless communication network.
Figure 5 is a diagram showing communication nodes constituting a wireless communication network.
Figure 6 is a diagram showing a downlink transmission burst in an unlicensed band according to an embodiment of the present invention.
Figures 7a, 7b, 7c, and 7d are diagrams showing the CCA configuration of an uplink transmission burst.
Figure 8 is a diagram showing a method of signaling CCA symbol configuration information through common DCI, according to an embodiment of the present invention.
Figure 9 is a diagram showing a method of updating CCA symbol configuration information through common DCI, according to an embodiment of the present invention.
Figures 10a and 10b are diagrams showing the SRS configuration position according to the CCA section according to an embodiment of the present invention.
Figures 11A and 11B are diagrams showing an unlicensed band uplink transmission burst according to an embodiment of the present invention.
Figures 12A, 12B, and 12C are diagrams showing transition subframes included in an unlicensed transmission burst according to an embodiment of the present invention.
Figure 13 is a diagram showing a multiple uplink scheduling method according to an embodiment of the present invention.

Below, with reference to the attached drawings, embodiments of the present invention will be described in detail so that those skilled in the art can easily implement the present invention. However, the present invention may be implemented in many different forms and is not limited to the embodiments described herein. In order to clearly explain the present invention in the drawings, parts that are not related to the description are omitted, and similar parts are given similar reference numerals throughout the specification.

In this specification, duplicate descriptions of the same components are omitted.

Also, in this specification, when a component is mentioned as being 'connected' or 'connected' to another component, it may be directly connected or connected to the other component, but may be connected to the other component in the middle. It should be understood that may exist. On the other hand, in this specification, when it is mentioned that a component is 'directly connected' or 'directly connected' to another component, it should be understood that there are no other components in between.

Additionally, the terms used in this specification are merely used to describe specific embodiments and are not intended to limit the present invention.

Also, in this specification, singular expressions may include plural expressions, unless the context clearly dictates otherwise.

In addition, in this specification, terms such as 'include' or 'have' are only intended to designate the presence of features, numbers, steps, operations, components, parts, or combinations thereof described in the specification, and one or more It should be understood that this does not exclude in advance the presence or addition of other features, numbers, steps, operations, components, parts, or combinations thereof.

Also, in this specification, the term 'and/or' includes a combination of a plurality of listed items or any of the plurality of listed items. In this specification, 'A or B' may include 'A', 'B', or 'both A and B'.

Also, in this specification, terminal refers to a mobile terminal, a station, a mobile station, an advanced mobile station, a high reliability mobile station, and a subscriber station. (subscriber station), portable subscriber station, access terminal, user equipment (UE), node, device, etc., terminal, mobile terminal , may include all or part of the functionality of a station, mobile station, advanced mobile station, high-reliability mobile station, subscriber station, portable subscriber station, access terminal, user equipment, node, device, etc.

Also, in this specification, a base station (BS) refers to an advanced base station, a high reliability base station, a node B (NB), an evolved node B, eNodeB, eNB), radio base station, radio transceiver, access point, access node, radio access station, base transceiver station , MMR (mobile multihop relay)-BS, may refer to a relay station that performs the role of a base station, a high reliability relay station that performs the role of a base station, a repeater, a macro base station, a small base station, etc., Base station, advanced base station, high reliability base station, NodeB, eNodeB, wireless base station, wireless transceiver, access point, access node, wireless access station, base transceiver station, MMR-BS, repeater, high reliability repeater, repeater, macro base station, small It may include all or part of the functions of a base station, etc.

Below, a method of configuring and transmitting a signal in a time division duplex (TDD) method in an unlicensed band wireless communication system will be described. Specifically, in the following, for unlicensed band time division (TDD), a channel access method, a method of configuring a frame of an unlicensed band cell and a method of transmitting frame configuration information, a scheduling method for allocating resources to a terminal, and channel status. Methods for transmitting measurement signals and response signals will be explained.

1, 2, 3, and 4 are diagrams showing an embodiment of a wireless communication network.

Specifically, FIGS. 1 to 4 illustrate a wireless communication network to which the method and device according to an embodiment of the present invention are applied. However, this is only an example, and the wireless communication network to which the method and device according to the embodiment of the present invention are applied is not limited to the wireless communication network described in this specification. The method and device according to embodiments of the present invention can be applied to various wireless communication networks.

1 illustrates an embodiment of a wireless communications network.

In the wireless communication network illustrated in FIG. 1, the first base station 110 may support cellular communication (e.g., LTE, LTE-A (advanced), LTE-U (unlicensed), etc. specified in 3GPP standards). there is. The first base station 110 supports multiple input multiple output (MIMO) (e.g., single user (SU)-MIMO, multi user (MU)-MIMO, massive MIMO, etc.), coordinated multipoint (CoMP), and carrier aggregation. (CA: carrier aggregation), etc. can be supported. The first base station 110 may operate in the licensed band (F1) and form a macro cell. The first base station 110 may be connected to another base station (eg, the second base station 120, the third base station 130, etc.) through an ideal backhaul or a non-ideal backhaul.

The second base station 120 may be located within the coverage of the first base station 110. The second base station 120 can operate in the unlicensed band (F3) and can form a small cell.

The third base station 130 may be located within the coverage of the first base station 110. The third base station 130 can operate in the unlicensed band (F3) and form a small cell.

Each of the second base station 120 and the third base station 130 may support WLAN defined in the IEEE 802.11 standard.

The first base station 110 and each terminal (e.g., UE) connected to the first base station 110 can transmit and receive signals through carrier aggregation (CA) between the licensed band (F1) and the unlicensed band (F3). .

2 illustrates another embodiment of a wireless communications network.

In the wireless communication network illustrated in FIG. 2, each of the first base station 210 and the second base station 220 may support cellular communications (e.g., LTE, LTE-A, LTE-U, etc. specified in 3GPP standards). . Each of the first base station 210 and the second base station 220 may support MIMO (eg, SU-MIMO, MU-MIMO, massive MIMO, etc.), CoMP, carrier aggregation (CA), etc. Each of the first base station 210 and the second base station 220 can operate in the licensed band (F1) and form a small cell. Each of the first base station 210 and the second base station 220 may be located within the coverage of a base station forming a macro cell. The first base station 210 may be connected to the third base station 230 through ideal backhaul or non-ideal backhaul. The second base station 220 may be connected to the fourth base station 240 through ideal backhaul or non-ideal backhaul.

The third base station 230 may be located within the coverage of the first base station 210. The third base station 230 can operate in the unlicensed band (F3) and can form a small cell.

The fourth base station 240 may be located within the coverage of the second base station 220. The fourth base station 240 can operate in the unlicensed band (F3) and can form a small cell.

Each of the third base station 230 and the fourth base station 240 can support WLAN specified in the IEEE 802.11 standard.

The first base station 210, the terminal connected to the first base station 210, the second base station 220, and the terminal connected to the second base station 220 each have a connection between the licensed band (F1) and the unlicensed band (F3). Signals can be transmitted and received through carrier aggregation (CA).

3 illustrates another embodiment of a wireless communications network.

In the wireless communication network illustrated in FIG. 3, the first base station 310, the second base station 320, and the third base station 330 each support cellular communication (e.g., LTE, LTE-A, LTE defined in the 3GPP standard). -U, etc.) can be supported. The first base station 310, the second base station 320, and the third base station 330 each perform MIMO (e.g., SU-MIMO, MU-MIMO, massive MIMO, etc.), CoMP, carrier aggregation (CA), etc. Support is available.

The first base station 310 may operate in the licensed band (F1) and form a macro cell. The first base station 310 may be connected to another base station (eg, the second base station 320, the third base station 330, etc.) through ideal backhaul or non-ideal backhaul.

The second base station 320 may be located within the coverage of the first base station 310. The second base station 320 may operate in the licensed band (F1) and form a small cell.

The third base station 330 may be located within the coverage of the first base station 310. The third base station 330 can operate in the licensed band (F1) and form a small cell.

The second base station 320 may be connected to the fourth base station 340 through ideal backhaul or non-ideal backhaul. The fourth base station 340 may be located within the coverage of the second base station 320. The fourth base station 340 can operate in the unlicensed band (F3) and can form a small cell.

The third base station 330 may be connected to the fifth base station 350 through ideal backhaul or non-ideal backhaul. The fifth base station 350 may be located within the coverage of the third base station 330. The fifth base station 350 can operate in the unlicensed band (F3) and can form a small cell.

Each of the fourth base station 340 and the fifth base station 350 can support WLAN specified in the IEEE 802.11 standard.

A first base station 310, a terminal connected to the first base station 310, a second base station 320, a terminal connected to the second base station 320, a third base station 330, and a third base station 330. Each terminal connected to can transmit and receive signals through carrier aggregation (CA) between the licensed band (F1) and the unlicensed band (F3).

4 illustrates another embodiment of a wireless communication network.

In the wireless communication network illustrated in FIG. 4, the first base station 410, the second base station 420, and the third base station 430 each support cellular communication (e.g., LTE, LTE-A, LTE defined in 3GPP standards). -U, etc.) can be supported. The first base station 410, the second base station 420, and the third base station 430 each perform MIMO (e.g., SU-MIMO, MU-MIMO, massive MIMO, etc.), CoMP, carrier aggregation (CA), etc. Support is available.

The first base station 410 may operate in the licensed band (F1) and form a macro cell. The first base station 410 may be connected to another base station (eg, the second base station 420, the third base station 430, etc.) through ideal backhaul or non-ideal backhaul.

The second base station 420 may be located within the coverage of the first base station 410. The second base station 420 may operate in the licensed band (F2) and form a small cell.

The third base station 430 may be located within the coverage of the first base station 410. The third base station 430 can operate in the licensed band (F2) and form a small cell.

Each of the second base station 420 and the third base station 430 may operate in a licensed band (F2) different from the licensed band (F1) in which the first base station 410 operates.

The second base station 420 may be connected to the fourth base station 440 through ideal backhaul or non-ideal backhaul. The fourth base station 440 may be located within the coverage of the second base station 420. The fourth base station 440 can operate in the unlicensed band (F3) and can form a small cell.

The third base station 430 may be connected to the fifth base station 450 through ideal backhaul or non-ideal backhaul. The fifth base station 450 may be located within the coverage of the third base station 430. The fifth base station 450 can operate in the unlicensed band (F3) and can form a small cell.

Each of the fourth base station 440 and the fifth base station 450 can support WLAN specified in the IEEE 802.11 standard.

The first base station 410 and each terminal connected to the first base station 410 can transmit and receive signals through carrier aggregation (CA) between the licensed band (F1) and the unlicensed band (F3). The second base station 420, the terminal connected to the second base station 420, the third base station 430, and the terminal connected to the third base station 430 each have a connection between the licensed band (F2) and the unlicensed band (F3). Signals can be transmitted and received through carrier aggregation (CA).

Meanwhile, communication nodes (e.g., base stations, terminals, etc.) constituting a wireless communication network may transmit signals based on a listen before talk (LBT) procedure in an unlicensed band. That is, the communication node can determine the occupancy status of the unlicensed band by performing an energy detection operation. The communication node may transmit a signal when it is determined that the unlicensed band is in an idle state. At this time, the communication node may transmit a signal when the unlicensed band is in an idle state during a contention window according to a random backoff operation. On the other hand, if the communication node determines that the unlicensed band is in a busy state, the communication node may not transmit a signal.

Alternatively, the communication node may transmit signals based on a carrier sensing adaptive transmission (CSAT) procedure. That is, the communication node can transmit signals based on a preset duty cycle. A communication node may transmit a signal if the current duty cycle is the duty cycle assigned for a communication node supporting cellular communication. On the other hand, a communication node may not transmit a signal if the current duty cycle is the duty cycle allocated for a communication node supporting communication other than cellular communication (eg, WLAN, etc.). The duty cycle may be adaptively determined based on the number of communication nodes that exist in the unlicensed band and support WLAN, the usage status of the unlicensed band, etc.

A communication node can perform discontinuous transmission in an unlicensed band. For example, if the maximum transmission duration or maximum channel occupancy time (COT) is set in the unlicensed band, the communication node can transmit a signal within the maximum transmission period. If the communication node fails to transmit all signals within the current maximum transmission period, the remaining signals can be transmitted in the next maximum transmission period. Additionally, the communication node can select a carrier with relatively little interference in the unlicensed band and operate on the selected carrier. Additionally, when a communication node transmits a signal in an unlicensed band, it can adjust transmission power to reduce interference with other communication nodes.

Meanwhile, the communication node uses a communication protocol based on code division multiple access (CDMA), a communication protocol based on wideband CDMA (WCDMA), a communication protocol based on time division multiple access (TDMA), and a communication protocol based on frequency division multiple access (FDMA). , SC (single carrier)-FDMA-based communication protocol, OFDM (orthogonal frequency division multiplexing)-based communication protocol, OFDMA (orthogonal frequency division multiple access)-based communication protocol, etc. can be supported.

Figure 5 is a diagram showing a communication node (or computing device) constituting a wireless communication network. The communication node 500 may be a base station or a terminal described in this specification.

In the embodiment of FIG. 5 , the communication node 500 may include at least one processor 510, a transceiver device 520 that is connected to a network and performs communication, and a memory 530. Additionally, the communication node 500 may further include a storage device 540, an input interface device 550, an output interface device 560, etc. Components included in the communication node 500 are connected by a bus 570 and can communicate with each other.

The processor 510 may execute a program command stored in at least one of the memory 530 and the storage device 540. The processor 510 may refer to a central processing unit (CPU), a graphics processing unit (GPU), or a dedicated processor on which methods according to embodiments of the present invention are performed. Processor 510 may be configured to implement procedures, functions, and methods described in connection with embodiments of the invention. The processor 510 can control each component of the communication node 500.

Each of the memory 530 and the storage device 540 can store various information related to the operation of the processor 510. Each of the memory 530 and the storage device 540 may be comprised of at least one of a volatile storage medium and a non-volatile storage medium. For example, the memory 530 may be comprised of at least one of read only memory (ROM) and random access memory (RAM).

The transceiving device 520 can transmit or receive a wired signal or a wireless signal. And the communication node 500 may have a single antenna or multiple antennas.

Meanwhile, in a wireless communication network, a communication node may operate as follows. Even when a method (e.g., transmission or reception of a signal) performed in a first communication node among communication nodes is described, the second communication node corresponding to the first communication node corresponds to the method performed by the first communication node. A method (e.g., receiving or transmitting a signal) can be performed. That is, when the operation of the terminal is described, the base station corresponding to the terminal can perform the operation corresponding to the operation of the terminal. Conversely, when the operation of the base station is described, the terminal corresponding to the base station may perform an operation corresponding to the operation of the base station.

In long term evolution (LTE) downlink (DL), one subframe consists of two time slots (1st time slot, 2nd time slot). Each time slot consists of 7 or 6 time domain symbols (eg, OFDM symbols). That is, one subframe may include 14 time domain symbols (eg, time domain symbols 0 to 13) or 12 time domain symbols (eg, time domain symbols 0 to 11). In this specification, the time domain symbol may be an OFDM symbol, OFDMA symbol, or SC-FDMA symbol, etc., depending on the multiple access method. For example, when OFDM symbols are used herein, the OFDM symbols can be replaced with SC-FDMA symbols, and vice versa.

Up to 3 or 4 OFDM symbols configured in the front of the subframe include control channels. The downlink control channel in the licensed band may include, for example, a physical control format indicator channel (PCFICH), a physical downlink control channel (PDCCH), a physical hybrid automatic repeat request indicator channel (PHICH), etc. The remaining part of the subframe is basically allocated to a physical downlink shared channel (PDSCH), a data channel for data transmission, and an enhanced physical downlink control channel (EPDCCH) may be allocated to some resource blocks (RBs). .

The first OFDM symbol within the subframe includes a PCFICH that transmits information about the number of OFDM symbols used for transmission of the control channel. Additionally, the control channel area may include a PHICH that transmits a hybrid automatic repeat request (HARQ) ACK/NACK (acknowledgment/negative-acknowledgment) signal, which is response information for uplink (UL) transmission. Downlink control information (DCI), which is control information, is transmitted through PDCCH and ePDCCH. DCI may include resource allocation information or resource control information for a terminal and multiple terminal groups. For example, DCI may include uplink scheduling information, downlink scheduling information, uplink transmit power control command, etc.

DCI, which is control information transmitted through PDCCH or ePDCCH, has different formats depending on the type and number of information fields, number of bits of each information field, etc. DCI formats 0, 3, 3A, 4, and 4A are defined for uplink. DCI formats 1, 1A, 1B, 1C, 1D, 2, 2A, 2B, 2C, 2D, etc. can be defined for downlink. Each DCI format includes a carrier indicator field (CIF), RB assignment, modulation coding scheme (MCS), redundancy version (RV), new data indicator (NDI), transmit power control (TPC), and HARQ process. Information such as number, PMI (precoding matrix indicator) confirmation, hopping flag, flag field, etc. is optionally included depending on the format. Therefore, the size of control information suitable for the DCI format may vary. Additionally, the same DCI format can be used to transmit two or more types of control information. In this case, control information is classified by the flag field of the DCI format. Table 1 below summarizes the information included in each DCI format.

DCI Format information Format 0 Resource grants for the PUSCH transmissions (uplink) Format 1 Resource assignments for single codeword PDSCH transmissions (transmission modes 1, 2 and 7) Format 1A Compact signaling of resource assignments for single codeword PDSCH (all modes) Format 1B Compact resource assignments for PDSCH using rank-1 closed loop precoding (mode 6) Format 1C Very compact resource assignments for PDSCH (e.g., paging/broadcast system information) Format 1D Compact resource assignments for PDSCH using multi-user MIMO (mode 5) Format 2 Resource assignments for PDSCH for closed-loop MIMO operation (mode 4) Format 2A Resource assignments for PDSCH for open-loop MIMO operation (mode 3) Format 3/3A Power control commands for PUCCH and PUSCH with 2-bit/1-bit power adjustments

PDCCH (or ePDCCH) is transmitted through the aggregation of one or more consecutive control channel elements (CCE) (or enhanced CCE (eCCE)). In this specification, PDCCH or ePDCCH is referred to as (e)PDCCH, and CCE or eCCE is referred to as (e)CCE.

(e) CCE is a logical allocation unit and consists of multiple REGs (resource element groups). The number of bits transmitted through (e)PDCCH is determined according to the relationship between the number of (e)CCEs and the code rate provided by (e)CCE.

A cyclic redundancy check (CRC) for error detection is attached to control information transmitted through (e)PDCCH according to the DCI format. In the CRC, an identifier (radio network temporary identifier) is masked depending on the (e)PDCCH reception target (e.g., terminal, etc.) or (e)PDCCH reception purpose. Specifically, a CRC scrambled based on the RNTI is attached to control information transmitted through (e)PDCCH.

The types and values of RNTI can be organized as shown in Table 2 below.

Value (hexa-decimal) RNTI 0000 N/A 0001-003C RA-RNTI, C-RNTI, Semi-Persistent Scheduling C-RNTI, Temporary C-RNTI, eIMTA-RNTI, TPC-PUCCH-RNTI, TPC-PUSCH-RNTI, and SL-RNTI 003D-FFF3 C-RNTI, Semi-Persistent Scheduling C-RNTI, eIMTA-RNTI, Temporary C-RNTI, TPC-PUCCH-RNTI, TPC-PUSCH-RNTI, and SL-RNTI FFF4-FFFC Reserved for future use FFFD M-RNTI FFFE P-RNTI FFFF SI-RNTI

The purpose of each RNTI is shown in Table 3 below.

RNTI Usage P-RNTI Paging and System Information change notification SI-RNTI Broadcast of System Information M-RNTI MCCH Information Change notification RA-RNTI Random Access Response eIMTA-RNTI eIMTA TDD UL/DL Configuration Notification Temporary C-RNTI Content Resolution
(when no valid C-RNTI is available) Temporary C-RNTI Msg3 transmission C-RNTIs Dynamically scheduled unicast transmission (uplink or downlink) C-RNTIs Triggering of PDCCH ordered random access Semi-Persistent Scheduling C-RNTI Semi-Persistently scheduled unicast transmission (activation, reactivation, and retransmission) Semi-Persistent Scheduling C-RNTI Semi-Persistently scheduled unicast transmission (deactivation) TPC-PUCCH-RNTI Physical layer uplink power control TPC-PUSCH-RNTI Physical layer uplink power control SL-RNTI Dynamically scheduled sidelink transmission

An identifier related to an unlicensed band cell can be defined as follows.

In this specification, for convenience, the identifier related to the unlicensed band cell is called U-RNTI (unlicensed cell-RNTI) or CC-RNTI (eg, a designated identifier of common information for unlicensed band). U-RNTI or CC-RNTI defined in this specification may be named differently depending on information on the unlicensed band cell. The value for U-RNTI or CC-RNTI can be delivered to the terminal by a higher layer message or a radio resource control (RRC) message. The value of U-RNTI or CC-RNTI defined in this specification may be known through RRC signaling. DCI including a CRC masked through U-RNTI or CC-RNTI may be transmitted through the unlicensed band PDCCH common search space. DCI including a CRC masked through U-RNTI or CC-RNTI may include common control information of unlicensed band cells. For example, information about a partial subframe (e.g., a length smaller than 1 ms transmission time interval (TTI)) of a downlink transmission burst may be included in the DCI. Alternatively, common control information of the unlicensed band uplink may be included in the DCI. For example, a counter value of random backoff for channel access of an uplink transmission burst may be included in the DCI. For another example, the number of consecutive uplink subframes to be scheduled may be specified through DCI.

1. Structure of unlicensed band LTE frame

Frame structure type 3 (FST-3) of the LTE system is applied to a licensed-assisted-access (LAA) secondary cell (SCell) with a normal cyclic prefix (CP).

FST-3 may be composed of a continuous set of downlink subframes (1 ms long) (hereinafter referred to as 'downlink transmission burst'). Here, the starting downlink partial subframe consisting of the second time slot or the ending downlink partial subframe consisting of time domain symbols of the length of the downlink pilot time slot (DwPTS) is the start of the downlink transmission burst. Can be included at the end of each lesson. A channel occupancy signal may be included for the purpose of channel occupancy before or at the end of transmission of a downlink transmission burst.

Figure 6 is a diagram showing a downlink transmission burst in an unlicensed band according to an embodiment of the present invention.

Specifically, in Figure 6, the downlink transmission burst is divided into two types of downlink partial subframes (e.g., a starting downlink partial subframe consisting of the second time slot, a last downlink partial subframe of DwPTS length), M (e.g. , 4) downlink subframes (e.g., 1ms TTI subframe), and a channel occupancy signal located before and after the downlink transmission burst is illustrated. Depending on the transmission time environment, the downlink transmission burst may not include partial subframes or channel occupancy signals.

Meanwhile, FST-3 may also be composed of a continuous set of uplink subframes (hereinafter referred to as 'uplink transmission burst'). An uplink transmission burst may be defined as a continuous uplink set from the transmission perspective of each terminal, or may be defined as a continuous uplink set from the reception perspective of the base station.

Each subframe of an uplink transmission burst may include a channel state measurement (e.g., clear channel assessment (CCA)) section to determine whether the channel is occupied or empty. The CCA section (e.g., a section where the occupancy status of the unlicensed band channel is measured) may be configured in front of the subframe and may be composed of at least one SC-FDMA symbol. Alternatively, the CCA section may be configured behind a subframe and may be composed of at least one SC-FDMA symbol.

The CCA section configured in front or behind a subframe may be configured in all uplink subframes or only in a specific uplink subframe.

When the CCA section is configured only in a specific uplink subframe, the terminal receives related information included in the DCI of the downlink that grants a specific uplink subframe containing the CCA section, and You can check a specific uplink subframe. Or, in the case where the CCA section is configured only in a specific uplink subframe, the UE transmits a common DCI (CRC is masked through CC-RNTI) in the downlink including a DCI that grants a specific uplink subframe including the CCA section. ), the specific uplink subframe containing the CCA section can be confirmed. Here, the related information may include at least one of CCA configuration status, CCA method (eg, random backoff or single CCA slot), CCA configuration symbol length, random backoff value, and collision window size value.

When a CCA section is configured, the UE does not configure a physical uplink shared channel (PUSCH) or a physical uplink control channel (PUCCH) in the resource element (RE) of the time domain symbol(s) belonging to the CCA section.

The method for the terminal to check the CCA configuration length is as follows. For example, the UE can immediately check the CCA configuration length through the number of CCA configuration symbols included in the DCI (e.g., the number of time domain symbols constituting the CCA section). In this specification, the CCA symbol refers to a time domain symbol that can be used for CCA. For another example, the terminal can check the number of CCA configuration symbols required according to the random backoff value included in the DCI. As another example, the terminal can check the number of CCA configuration symbols required according to the collision window size value included in the DCI. As another example, all UEs may know in advance that the CCA section is the first (or last) at least one time domain symbol among the time domain symbols of the subframe. For another example, the number of CCA configuration symbols or the CCA configuration symbol location (eg, the beginning of a subframe or the end of a subframe) may be transmitted to the UE by an RRC message of a higher layer. For another example, when two or more uplink subframes are successively granted in one downlink subframe, the terminal may use an uplink subframe after the first uplink subframe among the granted uplink subframes. One might expect that no CCA section is constructed.

The terminal can rate match and transmit the information it wants to transmit to the remaining REs excluding the RE corresponding to the time domain symbol configured for CCA.

Figures 7a, 7b, 7c, and 7d are diagrams showing the CCA configuration of an uplink transmission burst.

Figures 7a and 7b illustrate a case where a CCA section is configured behind a subframe. For example, Figure 7a illustrates a case in which a CCA section is configured in all M (e.g., 4) uplink subframes included in an uplink transmission burst, and Figure 7b illustrates a case in which a CCA section is configured in all M (e.g., 4) uplink subframes included in an uplink transmission burst. A case in which a CCA section is configured only in the second and fourth subframes among M (e.g., 4) uplink subframes is exemplified.

Figures 7c and 7d illustrate a case where a CCA section is configured in front of a subframe. For example, Figure 7c illustrates a case in which a CCA section is configured in all M (e.g., 4) uplink subframes included in an uplink transmission burst, and Figure 7d illustrates a case where a CCA section is configured in all M (e.g., 4) uplink subframes included in an uplink transmission burst. A case in which a CCA section is configured only in the first and third subframes among M (e.g., 4) uplink subframes is exemplified.

Meanwhile, information on the above-described CCA symbol configuration may be dynamically known to the terminal. A time domain in which CCA can be performed, where the base station transmits to the terminal information indicating the location of the time domain symbol at which uplink transmission begins among a plurality of time domain symbols included in the subframe (hereinafter referred to as 'first location information'). The terminal can be informed whether a symbol (or CCA section) is configured (set) in front of a subframe (e.g., the 1st time slot of the subframe). For example, the base station instructs the terminal to start uplink transmission from the first time domain symbol (e.g., time domain symbol No. 0) or start uplink transmission from the second time domain symbol (e.g., time domain symbol No. 1). (In this case, time domain symbol 0 is used for CCA). That is, when the CCA section is not set in the front of the subframe (e.g., the 1st time slot), the first location information generated by the base station is the first location information among a plurality of time domain symbols included in the subframe. It can represent a time domain symbol (e.g., time domain symbol number 0). If the CCA section is set in front of the subframe (e.g., the 1st time slot), the first location information is the earliest time domain symbol (e.g., time domain symbol) among a plurality of time domain symbols included in the subframe. 0) and a different time domain symbol (e.g., time domain symbol 1).

The base station transmits to the terminal information indicating the location of the time domain symbol at which uplink transmission ends among a plurality of time domain symbols included in the subframe (hereinafter referred to as 'second location information'), and provides a time domain in which CCA can be performed. The terminal can be informed whether a symbol (or CCA section) is configured (set) behind a subframe (e.g., the second time slot of the subframe). For example, the base station instructs the terminal to perform uplink transmission up to the last time domain symbol (e.g., time domain symbol No. 13), or uplink transmission only up to the penultimate time domain symbol (e.g., time domain symbol No. 12). (In this case, time domain symbol number 13 is used for CCA). That is, when the CCA section is not set at the rear of the subframe (e.g., the second time slot), the second location information generated by the base station is the rearmost of a plurality of time domain symbols included in the subframe. It can represent a time domain symbol (e.g., time domain symbol No. 13). If the CCA section is set at the rear of the subframe (e.g., the second time slot), the second location information is the rearmost time domain symbol (e.g., time domain symbol) among a plurality of time domain symbols included in the subframe. 13) and other time domain symbols (e.g., time domain symbol 12).

Alternatively, the base station can signal the number of time domain symbols for uplink transmission to the terminal and inform it of whether a time domain symbol (or CCA section) on which CCA can be performed is located behind the subframe. For example, the base station can inform the terminal of CCA symbol configuration information behind the subframe by signaling to the terminal that the number of time domain symbols that the terminal can use for uplink transmission is 13 or 12.

The terminal provides CCA symbol configuration information for the front of the subframe (e.g., information about time domain symbols located in front of the subframe and can be used for CCA) along with CCA symbol configuration information for the back of the subframe (e.g., subframe By checking (information about time domain symbols that are located behind and can be used for CCA), the CCA symbol configuration information of the corresponding subframe can be determined.

The above-described CCA symbol configuration information (or information on time domain symbols constituting the CCA interval) (e.g., number or location of CCA symbols, etc.) may be included in UE-specific DCI. Alternatively, the base station can inform the terminal of CCA symbol configuration information for multiple uplink subframes through the unlicensed band common DCI. For example, the base station may transmit first location information and second location information to the terminal through UE-specific DCI or common DCI.

Since the terminal must demodulate the common DCI of the unlicensed band cell, regardless of whether the uplink grant is cross-carrier scheduling in the licensed band or the uplink grant is self-scheduled in the unlicensed band, the terminal You can check the CCA symbol configuration information. For example, the base station may signal CCA configuration information for M subframes of the unlicensed band cell to the terminal.

Common DCI information may not be delivered in all downlink subframes. In this case, the terminal can expect the preceding common DCI information to be valid.

CCA symbol configuration information may be updated with information included in the newly received common DCI. For example, CCA symbol configuration information included in the common DCI of the nth downlink subframe (e.g., CCA symbol configuration information for the (n+6)th subframe) and the (n+1)th downlink subframe If the CCA symbol configuration information (e.g., CCA symbol configuration information for the (n+6)th subframe) included in the common DCI is different, the terminal may follow the common DCI information of the (n+1)th subframe. .

Figure 8 is a diagram showing a method of signaling CCA symbol configuration information through common DCI, according to an embodiment of the present invention.

Specifically, Figure 8 illustrates a case where the base station informs the terminal of CCA symbol configuration information for M (eg, 6) uplink subframes through the common DCI.

Among the two tuple bits, one bit represents CCA symbol configuration information for the front of the subframe (e.g., 0: transmission starts at time domain symbol number 0, 1: transmission starts at time domain symbol number 1), and the remaining bits One bit may represent CCA symbol configuration information for the rear of the subframe (e.g., 0: perform transmission up to time domain symbol number 13, 1: perform transmission up to time domain symbol number 12). That is, a bit pair representing a CCA section for one subframe may include one bit for first location information and one bit for second location information.

For example, the base station transmits six uplink subframes (e.g., (n+4)th to (n+) after a predetermined time from the nth subframe through the common DCI of the nth subframe (downlink subframe). CCA symbol configuration information for the 9)th subframe) can be informed to the terminal. FIG. 8 illustrates a case where the predetermined time corresponds to 4 subframes (eg, 4 ms). CCA symbol configuration information transmitted to the terminal may include a bit pair (or tuple bits) representing the CCA section for each uplink subframe (e.g., (n+4)th to (n+9)th subframe). there is. As illustrated in FIG. 8, when the CCA symbol configuration information included in the common DCI is [10 00 11 01 10 10], time domain symbol number 0 of the (n+4)th subframe can be used for CCA. (tuple bits=10), the (n+5)th subframe does not contain a CCA symbol (tuple bits=00), and time domain symbols 0 and 13 of the (n+6)th subframe will be used for CCA. (tuple bits=11), time domain symbol number 13 of the (n+7)th subframe can be used for CCA (tuple bits=01), and time domain symbol number 0 of the (n+8)th subframe is It can be used for CCA (tuple bits=10), and time domain symbol 0 of the (n+9)th subframe can be used for CCA (tuple bits=10).

Figure 9 is a diagram showing a method of updating CCA symbol configuration information through common DCI, according to an embodiment of the present invention.

Specifically, in Figure 9, it is included in the common DCI of the nth downlink subframe (e.g., the first time point) and the common DCI of the (n+1)th downlink subframe (e.g., the second time point after the first time point). As the CCA symbol configuration information changes, the CCA configuration of the (n+7)th subframe is exemplified.

For example, the base station transmits six uplink subframes (e.g., (n+4)th to (n+9) after a predetermined time from the nth downlink subframe through the common DCI of the nth downlink subframe. CCA symbol configuration information for the th subframe) can be informed to the terminal. FIG. 9 illustrates a case where the predetermined time corresponds to 4 subframes (eg, 4 ms). If the CCA symbol configuration information included in the common DCI of the nth downlink subframe is [10 10 01 01 11 10], time domain symbol number 0 of the (n+4)th subframe can be used for CCA ( tuple bits=10), time domain symbol number 0 of the (n+5)th subframe can be used for CCA (tuple bits=10), and time domain symbol number 13 of the (n+6)th subframe can be used for CCA. can be used (tuple bits=01), time domain symbol 13 of the (n+7)th subframe can be used for CCA (tuple bits=01), and time domain symbol 0 of the (n+8)th subframe Numbers 1 and 13 can be used for CCA (tuple bits=11), and time domain symbol 0 of the (n+9)th subframe can be used for CCA (tuple bits=10).

In this situation, if the CCA symbol configuration information included in the common DCI of the (n+1)th downlink subframe is [10 01 11 11 10 01], M (e.g., 6) uplink subframes ( Yes, CCA symbol configuration information for (n+5)th to (n+10)th subframes) can be updated. That is, time domain symbol number 0 of the (n+5)th subframe can be used for CCA (tuple bits=10), and time domain symbol number 13 of the (n+6)th subframe can be used for CCA ( tuple bits=01), time domain symbols 0 and 13 of the (n+7)th subframe can be used for CCA (tuple bits=11), and time domain symbol 0 of the (n+8)th subframe and 13 can be used for CCA (tuple bits=11), and time domain symbol number 0 of the (n+9)th subframe can be used for CCA (tuple bits=10), and the (n+10)th subframe Time domain symbol number 13 of the frame can be used for CCA (tuple bits=01). For example, when the CCA section for the (n+7)th subframe changes, the base station changes the value of the bit pair (or tuple bits) representing the CCA section of the (n+7)th subframe, CCA symbol configuration information (e.g., [10 01 11 11 10 01]) including the changed bit pair can be transmitted to the terminal in the (n+1)th downlink subframe.

Meanwhile, when a CCA symbol is configured at the front of a subframe and signal transmission starts from the second time domain symbol (e.g., time domain symbol No. 1) of the subframe, the terminal transmits the first time domain symbol (e.g., time domain symbol No. 1) according to the LBT result. , a signal can be transmitted at any sample position within the interval of time domain symbol number 0). In this case, the signal transmitted in the section of the first time domain symbol (e.g., time domain symbol number 0) may be an arbitrary signal for channel occupancy, and the terminal transmits the original first time domain symbol (e.g., time domain symbol number 0). ) can be punctured to transmit an arbitrary signal to occupy the channel.

The last time domain symbol (e.g., SC-FDMA symbol) of the LTE uplink subframe may be configured as a sounding reference signal (SRS). When the CCA section (or CCA symbol) of the unlicensed band uplink is configured, for example, the SRS may be configured immediately after the first CCA section or immediately before the last CCA section. The case where SRS is included in the embodiment of FIGS. 7A and 7C described above will be described in detail with reference to FIGS. 10A and 10B.

Figures 10a and 10b are diagrams showing SRS configuration positions according to CCA sections according to an embodiment of the present invention.

Specifically, in Figure 10a, a CCA section is configured in all M (e.g., 4) uplink subframes included in the uplink transmission burst (the CCA section is configured behind the subframe), and the SRS is configured in front of the CCA section. An example is provided.

In Figure 10b, a CCA section is configured in all M (e.g., 4) uplink subframes included in the uplink transmission burst (the CCA section is configured in front of the subframe) and the SRS is configured after the CCA section. It is illustrated.

Meanwhile, in an unlicensed band uplink transmission burst, the existing SRS transmission location may be configured as a section for channel state measurement (CCA). When the SRS (or SRS section) consists of a CCA section, the PUCCH of the subframe containing the corresponding CCA section may be transmitted in a Shortened PUCCH structure, and SRS is not transmitted in the corresponding CCA section. Here, Shortened PUCCH refers to a PUCCH with a shorter length than the existing PUCCH. The corresponding CCA section can be used for CCA purposes for the terminal allocated to the next uplink subframe. One or more subframes including the CCA interval may be included in an uplink transmission burst.

Alternatively, CCA and SRS transmission may be performed during the period of the last time domain symbol (e.g., SC-FDMA symbol) within the subframe. The SRS in this case has a shorter length than the existing SRS, and hereinafter it is referred to as 'Shortened SRS'. Shortened SRS may not be an SRS composed of two RE intervals, but may be an SRS composed of two or more RE intervals. For example, if an SRS is configured with four RE intervals, a repeating pattern appears during a time domain symbol (e.g., SC-FDMA symbol) in the time domain (or time domain), and the Shortened SRS is one of the four repeating patterns. Only one, two, or three repeating patterns can be transmitted. And the remaining section (e.g., remaining repetitive pattern) can be used for CCA. One or more subframes including the CCA section and Shortened SRS may be included in an uplink transmission burst.

Meanwhile, an uplink transmission burst may include an SRS symbol set consisting of one or more time domain symbols (eg, SC-FDMA symbols). That is, the SRS symbol set includes at least one time domain symbol for SRS transmission.

The SRS symbol set may be configured (located) in front of the uplink subframe set, like an uplink pilot time slot (UpPTS) of frame structure type 2 (FST-2). Alternatively, the SRS symbol set is composed of a number of time domain symbols (e.g., SC-FDMA symbols) (starting from the start of the subframe) and may be configured at the end of the uplink subframe set. Alternatively, the SRS symbol set may be configured (located) in the second time slot of the subframe.

Meanwhile, a physical random access channel (PRACH) may be included in front of the uplink transmission burst. PRACH can be configured independently of SRS or can be configured simultaneously with SRS through multiplexing of frequency domain resources (or frequency domain resources). Additionally, a channel occupancy signal may be included in front of the uplink transmission burst. With reference to FIGS. 11A and 11B, an unlicensed band uplink transmission burst will be described.

Figures 11A and 11B are diagrams showing an unlicensed band uplink transmission burst according to an embodiment of the present invention.

Specifically, Figure 11a illustrates a case where an SRS symbol set is configured at the front and rear of an uplink transmission burst. The SRS symbol set included at the front of the uplink transmission burst may include L time domain symbols (eg, SC-FDMA symbols) among the time domain symbols of the nth subframe. The SRS symbol set included behind the uplink transmission burst may have the same length as the second time slot of the subframe. For example, a PUSCH may be configured in the 1st time slot of the (n+5)th subframe, and an SRS symbol set may be configured in the 2nd time slot. The uplink transmission burst illustrated in FIG. 11A includes M (e.g., 4) uplink subframes (e.g., (n+1)th to (n+4)th subframes), where M uplink At least one of the subframes (e.g., (n+2)th subframe) may include a CCA section instead of an SRS section.

Specifically, at the front of the uplink transmission burst illustrated in FIG. 11b, L time domain symbols (eg, SC-FDMA symbols) in which PRACH and SRS are multiplexed may be configured (included). That is, among the time domain symbols of the nth subframe, multiplexed PRACH and SRS may be configured (included) in L time domain symbols. The SRS symbol set included behind the uplink transmission burst illustrated in FIG. 11b may include N time domain symbols (e.g., SC-FDMA symbols) among the time domain symbols of the (n+5)th subframe. there is. The uplink transmission burst illustrated in FIG. 11B includes M (e.g., 4) uplink subframes (e.g., (n+1)th to (n+4)th subframes), where M uplink At least one of the subframes (e.g., (n+2)th subframe) may include a CCA interval and a Shortened SRS interval instead of an SRS interval.

Meanwhile, in FST-3, the above-described downlink transmission burst and uplink transmission burst can be transmitted sequentially. Hereinafter, the continuously transmitted downlink transmission burst and uplink transmission burst are referred to as 'unlicensed transmission bursts'.

Between the downlink transmission burst and the uplink transmission burst within the unlicensed transmission burst, a section in which there is no signal transmission for a certain interval (hereinafter referred to as 'non-transmission section (No_Tx)') may be included.

In the case where the last subframe included in the downlink transmission burst and the next subframe are composed of consecutive uplinks, hereinafter, the last downlink subframe included in the downlink transmission burst is referred to as 'switch subframe'. It is said.

In the non-transmission section (No_Tx), CCA may be performed by the terminal according to a defined channel access procedure. With reference to FIGS. 12A, 12B, and 12C, the transition subframe will be described.

Figures 12A, 12B, and 12C are diagrams showing transition subframes included in an unlicensed transmission burst according to an embodiment of the present invention.

Specifically, FIGS. 12A, 12B, and 12C illustrate a set of signals included in the previously defined downlink transmission burst and uplink transmission burst.

A transition subframe can be configured by different sets of signals that can be included in the downlink transmission burst and the uplink transmission burst.

For example, as illustrated in FIG. 12A, the transition subframe may include a downlink partial subframe with a DwPTS length, a channel occupancy signal, a non-transmission period (No_Tx), and an SRS symbol set. Here, the SRS symbol set may include N time domain symbols among the time domain symbols of the transition subframe.

For another example, as illustrated in FIG. 12B, the transition subframe may include a downlink partial subframe with a DwPTS length, a non-transmission period (No_Tx), and a PRACH symbol set. Here, the PRACH symbol set may include at least one time domain symbol for PRACH transmission.

For another example, as illustrated in FIG. 12C, the transition subframe may include a downlink partial subframe with a DwPTS length, a channel occupation signal, and a non-transmission period (No_Tx).

2. Channel access procedure

In unlicensed bands, before a communication node transmits a burst, the channel status must first be checked according to the channel access procedure.

2.1. Downlink channel access procedure

The downlink channel access procedure may include a channel access procedure for a downlink transmission burst. Regarding the channel access procedure for downlink transmission bursts, different parameter values are defined depending on the classification of traffic that the communication node wishes to transmit. Table 4 below shows channel access priority classes according to the four classes (Voice, Video, BE (best effort), BK (background)) of traffic that the communication node wishes to transmit. The smaller the value of the channel access priority class, the higher the priority. Depending on the value of the channel access priority class, the collision window size (CWS: contention window size) and maximum occupancy time (Max. COT) are defined differently. In Table 4, K _slot is a channel access method (category 4) for wireless LAN and LAA that waits a certain amount of time from the moment the signal occupying the channel disappears and then transmits when the count value randomly selected from the CWS size becomes 0. Perform. Here, the constant time may consist of a fixed time of 16us and K _{slots (one slot} has a length of 9us).

Channel Access Priority Class K- _slot CWS for N _slot Max. COT 1 (Voice) One {3, 7} 2ms 2 (Video) One {7, 15} 3ms 3 (BE) 3 {15, 31, 63} 10ms or 8ms 4 (BK) 7 {15, 31, 63, 127, 255, 511, 1023} 10ms or 8ms

Meanwhile, there are two methods for CCA. The first CCA method is to perform CCA for a certain time (T) with a fixed length (e.g., 16us) and the number of CCA slots of K _slots . The second CCA method is to perform CCA during a time period that includes the number of CCA slots randomly selected among positive integers smaller than the collision window size (N _slot ) and greater than 0.

Depending on the access procedure class (or channel access priority class), a transmission opportunity (TxOP) that allows the communication node to continuously use the channel is defined.

In the case where the TxOP according to the channel access procedure for the downlink transmission burst also includes the uplink transmission burst, the channel access procedure for the downlink transmission burst uses the lowest priority parameters (e.g., K _slot = 7, N _slot = {15, 31, 63, 127, 255, 511, 1023}, Max. COT = 10ms or 8ms).

In order for a communication node to transmit a downlink subframe containing a DCI for allocation of an uplink subframe, the channel access procedure parameters of the lowest priority (e.g., K _slot = 7, N _slot = {15, 31, 63, 127, 255, 511, 1023}, Max. COT = 10ms or 8ms) can be used.

2.2. Uplink channel access procedure

For uplink transmission bursts, three channel access procedures can be defined.

In the first UL method, a communication node transmits a subframe consisting of an uplink signal (or channel) at a scheduled time without confirming the channel occupancy status.

In the second UL method, the communication node checks the channel occupancy status for a fixed length and transmits a subframe consisting of an uplink signal (or channel) when the channel is not occupied.

In the third UL method, a communication node checks the channel occupancy status during a randomly selected CCA slot length and transmits a subframe consisting of an uplink signal (or channel) when the channel is not occupied.

The first UL method can be used for the next transmission.

For example, within TxOP composed of parameters for the lowest priority of the downlink channel access priority class, an uplink transmission burst transmitted after a non-transmission section (No_Tx) of a certain length after a downlink transmission burst. Transmission of can be performed at a scheduled time without checking the channel status.

For another example, the maximum time for continuous transmission within one TxOP section is defined, and transmission of an uplink transmission burst transmitted after a non-transmission section (No_Tx) of a certain length after the maximum continuous transmission time is performed by checking the channel state. It can be performed at a scheduled time without any intervention.

For another example, transmission of uplink subframes transmitted subsequent to the first subframe of an uplink transmission burst during one TxOP period may be performed at a scheduled time without checking the channel state. Here, the first subframe may be an uplink subframe including a PUSCH, or a subframe composed of a PRACH symbol set or SRS symbol set with a length of 1 ms or less. The first subframe may be transmitted by the terminal after the channel occupancy status is confirmed immediately before transmission, according to transmission conditions. A terminal that has been scheduled (or allocated) to a subframe after the first subframe may not be scheduled for the first subframe. Although the communication node does not check the channel occupancy status immediately before transmitting subframes after the first subframe, a non-transmission period (No_Tx) of a certain length may be configured. That is, a specific terminal may not be scheduled for the first subframe of the uplink burst scheduled by the base station to multiple terminals. For the terminals in which the first subframe (where channel connection status is checked) is not included in the scheduled subframe, the base station can configure a non-transmission period (No_Tx) of a certain length between subframes. For example, the length of the non-transmission section (No_Tx) may be 9us, 16us, 25us, 34us, or hundreds of us. The terminal can confirm that the scheduled subframe is not the first subframe of the uplink transmission burst through the DCI message in the (e)PDCCH scheduling the subframe. For example, the first subframe and subsequent subframes can be distinguished by 1 bit.

For another example, a UE that has confirmed the channel occupancy status at least once during one TxOP interval may perform uplink transmission or SRS transmission of a discontinuously scheduled subframe without checking the channel occupancy status immediately before the transmission. You can. In this case, the last certain section in the previous subframe of the subframe scheduled for the terminal may be configured as a non-transmission section (No_Tx) for the terminal that first scheduled the TxOP. However, the terminal may not need to additionally check the channel occupancy status.

For another example, after a communication node (e.g., a terminal) transmits the first SRS in an SRS symbol set, it is possible to transmit subsequent SRSs without confirming the channel occupancy status. In this case, the communication node (eg, terminal) can check the channel occupancy status immediately before the first SRS transmission. Additionally, even when a terminal that did not initially transmit an SRS transmits subsequent SRSs except the first SRS, the terminal can perform SRS transmission without confirming the channel occupancy status.

For another example, uplink transmission including only the SRS symbol set and not PUSCH may be performed at a scheduled time without checking the channel state. In this case, the communication node (e.g., terminal) can perform uplink transmission including only the SRS symbol set without confirming the channel occupancy status after the downlink transmission burst ends and after a certain length of non-transmission section (No_Tx). there is. Here, the length of the non-transmission section (No_Tx) may be 9us, 16us, 25us, 34us, or hundreds of us.

For another example, transmission of an uplink subframe containing only PUCCH and not PUSCH may be performed at a scheduled time without checking the channel state. In this case, the communication node (e.g., terminal) may transmit an uplink subframe containing only the PUCCH without confirming the channel occupancy status after the downlink transmission burst ends and a certain length of non-transmission period (No_Tx). Here, the length of the non-transmission section (No_Tx) may be 9us, 16us, 25us, 34us, or hundreds of us.

For another example, uplink transmission including only PRACH and not PUSCH may be performed at a scheduled time without checking the channel state. In this case, the communication node (e.g., terminal) can perform uplink transmission including only the PRACH without confirming the channel occupancy status after the downlink transmission burst ends and a non-transmission period of a certain length (No_Tx). Here, the length of the non-transmission section (No_Tx) may be 9us, 16us, 25us, 34us, or hundreds of us.

The second UL method can be used for the following transmission.

For example, a communication node (e.g., a terminal) may check the channel state for a certain period of time before transmitting the first SRS or PRACH in the transition subframe after the downlink transmission burst during one TxOP interval. Alternatively, a communication node (eg, terminal) may check the channel status for a certain period of time before transmitting the first uplink subframe (including PUSCH) after the downlink transmission burst. Here, the predetermined time for checking the channel status may be a time consisting of a predetermined time and a CCA slot. Alternatively, the constant time for checking the channel status may be 9us, 16us, 25us, 34us, or hundreds of us.

For another example, a communication node (eg, terminal) may check the channel status for a certain period of time immediately before transmitting an SRS. Here, the predetermined time for checking the channel status may be a time consisting of a predetermined time and a CCA slot. Alternatively, the constant time for checking the channel status may be 9us, 16us, 25us, 34us, or hundreds of us.

As another example, a communication node (eg, terminal) may check the channel status for a certain period of time immediately before transmitting PRACH. Here, the predetermined time for checking the channel status may be a time consisting of a predetermined time and a CCA slot. Alternatively, the constant time for checking the channel status may be 9us, 16us, 25us, 34us, or hundreds of us.

The third UL method can be used for the following transmission.

For example, when a new TxOP starts from an uplink transmission burst, the third UL method may be applied to the transmission of the subframe including the first SRS, PRACH, or PUSCH.

For another example, the third UL method may be applied to SRS transmission temporally multiplexed with PUSCH within one subframe.

For another example, the third UL method may be applied to PRACH transmission temporally multiplexed with PUSCH within one subframe.

For another example, the third UL method may be applied to the transmission of an uplink subframe corresponding to the DCI of (e)PDCCH including information for uplink random channel access. When the carrier indicator field (CIF) of DCI format 0 or DCI format 4/4A indicates an unlicensed band cell, the number of slots for random backoff may be included in the DCI message.

For another example, the third UL method may be applied to the transmission of an uplink subframe scheduled as a cross carrier. The terminal may begin checking the channel occupancy status so that random backoff can be terminated at the time of transmission of the scheduled subframe. That is, regardless of the slot value for random backoff, the uplink transmission time is the same as the uplink transmission time for other cells within the same cell group. The time required to check the channel occupancy status may not exceed the length of one time domain symbol (eg, SC-FDMA symbol), and in this case, TxOP may be 1 ms. The time required to check the channel occupancy status may consist of only random backoff, or may consist of a fixed time and random backoff. (e) If the CIF of DCI format 0 or DCI format 4/4A of the PDCCH indicates an unlicensed band cell, a collision window value for random backoff may be included in the DCI message. The collision window value may be changed depending on the successful reception result of the previous uplink transmission burst. The collision window value included in the DCI message may be a bit string corresponding to a collision window set defined by a higher layer or a collision window set already defined in the standard. For example, if the collision window set is {3, 5, 7}, the collision window value included in the DCI message may consist of {01, 10, 11}. For another example, if the collision window set is {3, 5, 6, 7}, the collision window value included in the DCI message may consist of {00, 01, 10, 11}. Alternatively, the actual collision window value may be included in the DCI message.

(e) If the CIF of DCI format 0 or DCI format 4/4A of the PDCCH indicates an unlicensed band cell, the number of slots for random backoff may be included in the DCI message. This can be used to ensure that all terminals scheduled for the same uplink subframe perform the same backoff. For example, if the collision window set is {3, 5, 7}, the collision window value included in the DCI message may consist of {01, 10, 11}, and '00' is the collision window value to the terminal. Instead, it can be defined as passing a random backoff value. If the collision window field received by the terminal is '00', the terminal can expect the next field to contain a random backoff value.

Meanwhile, in the third UL method, the terminal can start checking the channel occupancy status so that random backoff can be ended at the start of transmission of the scheduled uplink transmission burst. That is, regardless of the slot value for random backoff, the uplink transmission time may be the same as the uplink transmission time for other cells in the same cell group. The time required to check the channel occupancy status may consist of only random backoff or a fixed time and random backoff. The random backoff value is selected within the collision window, and the collision window value can be changed depending on the result of successful reception of the previous uplink transmission burst. The terminal can determine the number of slots for random backoff from the collision window value included in the DCI or the actual number of random backoff slots. (e) When the CIF of DCI format 0 or DCI format 4/4A included in the PDCCH indicates an unlicensed band cell, the collision window value for random backoff selection or the actual random backoff value is included in the DCI message. May be included. The collision window value included in the DCI message may be a bit string corresponding to a collision window set defined by a higher layer or a collision window set already defined in the standard. For example, if the collision window set is {3, 5, 7}, the collision window value included in the DCI message may consist of {01, 10, 11}. For another example, if the collision window set is {3, 5, 6, 7}, the collision window value included in the DCI message may consist of {00, 01, 10, 11}. Alternatively, the collision window value and the actual random backoff value may be configured simultaneously. For example, if the collision window set is {3, 5, 7}, the collision window value included in the DCI message may consist of {01, 10, 11}, and '00' is the collision window value to the terminal. Instead, it can be defined as passing a random backoff value. If the collision window field that the terminal receives is '00', the terminal can expect the next field to contain a random backoff value.

3. Scheduling

In the uplink transmission subframe, scheduling for the subframe including the PUSCH may be scheduled by the downlink of the same cell (self-carrier scheduling) or scheduled by another cell in the cell group (cross-carrier scheduling). You can.

In self-carrier scheduling, it may be required to confirm whether a communication node (eg, terminal) should perform confirmation of the channel occupancy status immediately before transmitting the corresponding subframe. Additionally, dynamic scheduling for SRS transmission resources may be required. Such scheduling information may be included in DCI transmitted through the downlink PDCCH common search space.

In the DCI transmitted through the downlink PDCCH common search space in the unlicensed band, at least one of the following information (e.g., first information, second information, third information, fourth information, fifth information, and sixth information) may be included. Below, the 'corresponding subframe' refers to the (n+k)th subframe based on the nth downlink subframe in which a DCI containing at least one of the following information (e.g., first to sixth information) is transmitted. This means the frame (or the position of the (n+k)th subframe). For example, k may be 4.

The first information is information indicating whether the first subframe of the uplink transmission burst is configured in the corresponding subframe. The second information is information indicating whether confirmation of the channel occupancy status is performed immediately before the uplink subframe to be transmitted in the corresponding subframe. The third information is information indicating whether the corresponding subframe includes the SRS symbol set. The fourth information is information indicating whether the last time domain symbol (eg, SC-FDMA symbol) of the corresponding subframe is configured for SRS transmission. The fifth information is information indicating whether the last time domain symbol (eg, SC-FDMA symbol) of the corresponding subframe is configured to confirm the channel occupancy status. The sixth information is information for triggering SRS transmission within the corresponding subframe.

Meanwhile, in an unlicensed band cell, one downlink subframe can schedule multiple uplink subframes. For example, in relation to scheduling of uplink multiple subframes, DCI for delivering scheduling information can be configured through the following methods (eg, method M10, method M20, method M30). DCI information for at least one of the following methods (eg, method M10 to method M30) may be transmitted and included in one downlink subframe.

Method M10 is a method in which a base station uses one downlink subframe to provide scheduling information for different uplink subframes through two or more different DCIs. Here, the scheduling information may include the location of the first occupiable uplink subframe. In other words, the position of the first occupiable uplink subframe (e.g., may be included.

Method M20 is a method in which the base station uses one downlink subframe to provide scheduling information for two or more different uplink subframes through one DCI. Here, the scheduling information may include the number of consecutive subframes including the (n+4+X)th subframe based on the nth downlink subframe including the DCI.

Method M30 is a method in which the base station provides scheduling information specified through a predetermined bit length included in DCI with respect to one or more scheduling information defined by a higher layer message or RRC message.

In method M10, information about the subframe location may be additionally included in existing DCI formats for granting an uplink subframe. Here, information about the subframe location may be included in scheduling information (scheduling information for different uplink subframes) provided through two or more different DCIs transmitted in one downlink subframe.

Generally, in an LTE system, a DCI message (DCI message related to uplink scheduling) included in the n-th subframe is valid for the (n+4)-th uplink subframe. In the frame configuration (uplink and downlink frame configuration) conditions for TDD of LTE, uplink subframes are defined according to the downlink location where DCI is included. In the case of configuration 0 for TDD, an uplink index (UL index) field may be included in the DCI of the downlink subframe. The uplink index field is used to distinguish when uplink is configured in two subframes at different positions through one downlink subframe.

The location of the uplink subframe according to the value of the uplink index field may be predefined. For example, the information configuration method for method M10 is to configure the number of bits in the uplink index field to be two or more. When each DCI includes an uplink index field of 2 bits or more, the uplink index field may designate the (n+4+X)th subframe based on the nth downlink subframe containing the DCI. Here, X is a positive integer including 0 and can be defined according to the value of the uplink index field. The base station includes information (e.g., the value of the 'UL Index field') indicating the scheduled uplink subframe (e.g., (n+4+X ₁ )th subframe) in the first DCI, and Information (e.g., the value of _the 'UL Index field') representing the frame (e.g., (n+4+X ₂ )th subframe, where X ₁ ≠ It may be included, and the first DCI and the second DCI may be transmitted in a downlink subframe (e.g., n-th subframe).

For example, the 'UL Index' field may be composed of 3 bits (e.g., values from 0 to 7), as shown in Table 5 below, considering the maximum channel occupancy time (Maximum COT) of the unlicensed band. When the value of the 'UL Index' field is 1, the start of the downlink subframe (e.g., nth subframe) in which DCI is transmitted and the scheduled uplink subframe (e.g., (n+4+1)th subframe) The interval between the start of a frame corresponds to (4+1) subframes.

UL Index (value) X value at (n+4+X) 0 0 One One 2 2 3 3 4 4 5 5 6 6 7 7

Another information configuration method for method M10 is flexible timing information about the location of the scheduled (n+4+X)th uplink subframe, where the base station directly defines the It is done. The DCI for each uplink scheduling may be defined to include an X value.

In the two information configuration methods for method M10 described above, multiple uplink subframes of a predetermined subframe length may be configured to be consecutive, or may be configured to be discontinuous and have a gap.

In method M20, a method of configuring DCI information for multiple consecutive uplink subframe scheduling is to specify the number of consecutive subframes. Here, the number of consecutive subframes may be included in scheduling information (scheduling information for two or more different uplink subframes) provided through one DCI. For example, the first starting subframe may be the (n+4)th subframe based on the nth downlink subframe containing the DCI, or may be designated as a newly defined value in the DCI.

The number of continuously configured (or scheduled) subframes may be newly defined in DCI. For example, when 3 bits are used for DCI, the number of consecutive multiple uplink subframes including the (n+4)th subframe after the nth subframe in which DCI is received is 'multiple subframes'. Depending on the value of the 'frame number' field, it can be defined as shown in Table 6.

The value of the 'Number of multiple subframes' field Number of consecutive multiple uplink subframes including the (n+4)th subframe 0 One One 2 2 3 3 4 4 5 5 6 6 7 7 8

Meanwhile, the DCI formats for the above-described method M10 and method M20 may be simultaneously configured in one downlink subframe. In this case, the value of the 'number of multiple subframes' field and the value of the 'UL Index' field may be included in the DCI at the same time. That is, the base station can include information indicating the number of subframes to be continuously scheduled and information indicating the location of the first occupiable uplink subframe in the same DCI. For example, if the value of the 'number of multiple subframes' field is a pre-specified arbitrary value, the position of the uplink subframe may be specified through the 'UL Index' field included in the DCI. If the value of the 'Number of multiple subframes' field is 0, which is a pre-specified arbitrary value, instead of multiple consecutive subframes, the 'Number of multiple subframes' field is the subframe position specified by the value of the 'UL Index' field. It can be understood as uplink scheduling information for.

If the value of the 'Number of multiple subframes' field is not 0, the value of the 'Number of multiple subframes' field may mean the number of consecutive multiple subframes including the (n+4)th subframe. there is. In this case, the 'UL Index' field may not be included in the DCI.

Table 7 below shows a case where the 3-bit long 'number of multiple subframes' field and the 3-bit long 'UL Index' field are configured together in DCI. Specifically, in Table 7, when the value of the 'number of multiple subframes' field is 1 or more, the number of consecutive uplink subframes additionally configured in addition to the (n+4)th subframe can be considered. If the value of the 'Number of multiple subframes' field is 0, instead of multiple subframes in a row, the 'Number of multiple subframes' field is for the subframes specified by the value of the 'UL Index' field included in the same DCI. This refers to DCI information about the configured uplink scheduling. That is, when the value of the 'number of multiple subframes' field is a predetermined value (eg, 0), the location of the scheduled uplink subframe may be determined based on the value of the 'UL Index' field. If the value of the 'Number of multiple subframes' field is different from a predetermined value (e.g., 0), the location of the first uplink subframe among multiple scheduled uplink subframes is independent of the value of the 'UL Index' field. may be determined (e.g., (n+4)th subframe).

The value of the 'Number of multiple subframes' field What the value of the ‘Number of multiple subframes’ field indicates 0 Specifies multiple subframe positions according to the value of the 'UL Index' field One Scheduling one additional subframe after the (n+4)th subframe 2 Scheduling two additional subframes after the (n+4)th subframe 3 Scheduling 3 additional subframes after the (n+4)th subframe 4 Scheduling 4 additional subframes after the (n+4)th subframe 5 Scheduling 5 additional subframes after the (n+4)th subframe 6 Scheduling 6 additional subframes after the (n+4)th subframe 7 Scheduling 7 additional subframes after the (n+4)th subframe

Meanwhile, in another embodiment in which the value of the 'number of multiple subframes' field and the value of the 'UL Index' field are simultaneously included in the DCI, when the value of the 'UL Index' field is a specified arbitrary value, the 'number of multiple subframes' field is included in the DCI at the same time. ' The value of the field can be referenced. For example, if the value of the 'UL Index' field is 0, which is a pre-specified random value, the base station does not schedule only the subframe location defined by the 'UL Index' as uplink, but rather schedules the 'UL Index' field included in the same DCI. Depending on the value of the 'number of multiple subframes' field, multiple consecutive subframes can be scheduled as uplink.

Table 8 below shows a case where the 3-bit long 'UL Index' field and the 3-bit long 'Number of Multiple Subframes' field are configured together in one DCI. Specifically, in Table 8, when the value of the 'UL Index' field is 1 or more, the value of the 'UL Index' field may mean the value of X in (n+3+X). Here, the value of (n+3+X) means the location of the (n+3+X)th subframe (uplink subframe) scheduled through DCI information included in the nth subframe.

In Table 8, if the value of the 'UL Index' field is 0, uplink resources for multiple consecutive subframes can be scheduled according to the value of the 'Number of multiple subframes' field included in the same DCI. . That is, when the value of the 'UL Index' field is a predetermined value (eg, 0), the number of consecutively scheduled uplink subframes may be determined based on the value of the 'Number of multiple subframes' field. At this time, the location of the first scheduled uplink subframe may be determined (e.g., (n+4)th subframe) regardless of the value of the 'UL Index' field. If the value of the 'UL Index' field is different from a predetermined value (e.g., 0), the number of consecutively scheduled uplink subframes may be determined to be 1 regardless of the value of the 'Number of multiple subframes' field. .

The value of the 'UL Index' field What the value of the 'UL Index' field indicates 0 Scheduling uplink resources for multiple consecutive subframes according to the value of the ‘Number of multiple subframes’ field. One X value for the (n+3+X)th subframe position (e.g., (n+4)th subframe) 2 X value for the (n+3+X)th subframe position (e.g., (n+5)th subframe) 3 X value for the (n+3+X)th subframe position (e.g., (n+6)th subframe) 4 X value for the (n+3+X)th subframe position (e.g., (n+7)th subframe) 5 X value for the (n+3+X)th subframe position (e.g., (n+8)th subframe) 6 X value for the (n+3+X)th subframe position (e.g., (n+9)th subframe) 7 X value for the (n+3+X)th subframe position (e.g., (n+10)th subframe)

Meanwhile, method M30 relates to configuration information for one or more scheduling information (e.g., multiple subframe locations, etc.) defined by an RRC message or upper layer message and is based on the actual configuration instruction by the trigger field included in DCI. It's about. For example, the upper layer message or RRC message may include multiple subframe location information in the uplink that can be configured as described above.

This location information (or configuration information) can be a standard for including the 'Uplink Multiple Subframe Trigger' field in the DCI in the base station's downlink subframe. For example, while operating in an unlicensed band, each terminal can receive one or more uplink multiple subframe location information from the base station through an RRC message or higher layer message. Each such configuration information can be mapped to information of a certain bit length. The DCI includes a field that triggers the uplink multiple subframe location information (or configuration information) (i.e., 'Uplink multiple subframe Trigger' field), and the value of the 'Uplink multiple subframe Trigger' field is determined by the mapping. It may be the same as the information (e.g., information of a certain bit length). Each terminal can configure uplink multiple subframes according to the value of the 'Uplink multiple subframe Trigger' field included in the DCI.

Meanwhile, in frame structure type 3 for unlicensed band cells, in order to guarantee uplink transmission, a communication node can transmit uplink through a multiple scheduling method. Here, the multi-scheduling method involves a communication node performing scheduling in two steps.

In the first scheduling step of the multi-scheduling method, a communication node (e.g., base station) sends an uplink message containing information necessary for uplink transmission (e.g., location and number of RBs, HARQ-related information, LBT parameters, subframe location information, etc.). Link grant (UL grant) DCI can be transmitted.

In the secondary scheduling step of the multiple scheduling method, a communication node (eg, base station) may transmit scheduling information (hereinafter referred to as 'secondary scheduling information') that determines the actual uplink subframe transmission time.

Specifically, in the first scheduling step, a communication node (eg, base station) schedules at least one uplink subframe. Here, the subframe index actually transmitted by the communication node (eg, base station) may be fixed to be the same as the subframe index in the licensed band, or may be a virtual subframe index configured after the secondary scheduling step.

The terminal can receive secondary scheduling information for the secondary scheduling step through the PHICH or the common DCI of the unlicensed band cell. Specifically, secondary scheduling information may be defined as a PHICH sequence or may be delivered through the common DCI of an unlicensed band cell. Depending on the secondary scheduling step, the UE can change the LBT method or start an uplink subframe based on the secondary scheduling time. The multiple scheduling method will be described with reference to FIG. 13.

Figure 13 is a diagram showing a multiple uplink scheduling method according to an embodiment of the present invention.

Specifically, in FIG. 13, a communication node (e.g., base station) provides (n+5)th, (n+6)th, and (n+7)th uplink services through the uplink grant DCI in the first scheduling step. An example of scheduling a frame is provided. For example, the base station sends at least one uplink subframe (e.g., (n+5)th to (n+7)th subframes) to the terminal in the first downlink subframe (e.g., nth subframe). Primary scheduling information for scheduling can be transmitted.

When the terminal receives a downlink PHICH or common DCI containing secondary scheduling information, it can configure the uplink from a defined point in time. Here, the defined time point is a subframe (e.g., (k+1)th subframe or (k It may be the +2)th subframe). For example, the defined time point may be the (n+5)th subframe in FIG. 13. The base station transmits the uplink signal to the terminal in the second downlink subframe (e.g., (n+4)th subframe), which is a predetermined time away from the first downlink subframe (e.g., nth subframe). Secondary scheduling information that determines can be transmitted. The terminal selects an uplink subframe corresponding to the transmission time determined by the secondary scheduling information among the uplink subframes scheduled by the primary scheduling information (e.g., (n+5)th to (n+7)th subframes). In, an uplink signal can be transmitted.

Since HARQ response using PHICH is not performed in frame structure type 3, when the UE receives the defined sequence of PHICH in the kth subframe, the uplink transmission granted in the first scheduling step is performed in a specific subframe (e.g. It can be expected to be possible starting from the (k+1)th subframe or (k+2)th subframe).

If it is defined in the uplink grant of the first scheduling step that the LBT of category 4 is performed immediately before uplink transmission, the terminal receiving the secondary scheduling information of the second scheduling step uses the LBT of category 4 instead of the LBT of category 4. The LBT method can be changed by performing a single LBT of 25us. For example, the terminal that has received the secondary scheduling information checks the occupancy status of the unlicensed band channel for 25us before transmitting an uplink signal, and if the occupancy status of the unlicensed band channel is unoccupied, the terminal Uplink signals can be transmitted.

The sequence value of the PHICH sequence may be determined according to the first scheduling information (eg, uplink grant subframe index information) of the first scheduling step. Therefore, when the terminal detects the PHICH sequence (PHICH sequence for the second scheduling step) received in the k-th subframe (e.g., (n+4)-th subframe), the first scheduling information of the first scheduling step is expected to be valid, and the granted uplink can be transmitted starting from a specific subframe (e.g., the (k+1)th subframe or the (k+2)th subframe).

Using the information bits (e.g., at least 1 bit or more) included in the common DCI, the terminal can confirm the scheduling effectiveness of the secondary scheduling step. For example, in a method using the toggle concept, when a bit defined as 1 in the first scheduling step is changed to 0 in the kth subframe (e.g., (n+4)th subframe), the terminal It is confirmed that the scheduling of the scheduling step is valid, and uplink can be transmitted starting from a specific subframe (e.g., (k+1)th subframe or (k+2)th subframe).

For another example, the uplink grant DCI of the first scheduling step will not include fixed subframe information, but will include subframe index information based on the time when the secondary scheduling information of the second scheduling step is received. You can.

Specifically, in the first scheduling step, subframe index information for uplink subframe transmission may not be included in the uplink grant DCI. This is because the actual transmission time of the uplink subframe may vary depending on the channel occupancy results. Therefore, in the first scheduling step, uplink scheduling information excluding subframe information related to the transmission time can be delivered to the terminal. The terminal can detect an information bit (hereinafter referred to as 'first information bit') that informs (or indicates) a multi-scheduling method from the DCI (DCI of the first scheduling step) containing scheduling information. The first information bit may be included in DCI format 0A, DCI format 0B, DCI format 4A, or DCI format 4B. The first information bit is newly defined as 1 bit, or defined as the '1111' value (=15) of the 4-bit 'Timing offset' field included in DCI format 0A, DCI format 0B, DCI format 4A, or DCI format 4B. It can be. Here, the 'Timing offset' field refers to the k value at (n+4+k), which is the transmission time of the uplink subframe scheduled by the DCI transmitted in the nth subframe, and has a value from 0 to 15. You can have it. If the information indicating the multiple scheduling method (e.g., first information bit) is defined as 'Timing offset = 1111', if the value of the 'Timing offset' field is demodulated to 1111 and the scheduling of the second scheduling step is When detected, the terminal can transmit uplink at a designated time.

The value of the 'Timing offset' field, 1111, may be defined differently depending on whether the corresponding cell supports multiple scheduling. Whether or not multiple scheduling is supported may be signaled through an RRC message, etc. If the cell does not support multiple scheduling, k in (n+4+k) of the single scheduling method can be used as k=15. If the cell supports multiple scheduling, k can be used as a bit to indicate whether the DCI is a DCI for multiple scheduling. Or, when the field for informing of multiple scheduling is activated in the common DCI, if the value of the 'timing offset' field of DCI format 0A, DCI format 0B, DCI format 4A, or DCI format 4B transmitted in the corresponding subframe is 1111. If so, the corresponding DCI may be determined to be a DCI for multi-scheduling.

When scheduling of the secondary scheduling step is detected, the timing at which the terminal transmits uplink may be determined through at least one of the following three methods (eg, method M100, method M110, and method M120).

Method M100 involves the terminal transmitting uplink at a predefined time. Here, the predefined time point is a subframe (e.g., (m+1) a predetermined time after the mth subframe (e.g., (n+4)th subframe in FIG. 13) including scheduling of the second scheduling step. It may start at the )th subframe or the (m+2)th subframe).

Method M200 includes transmission subframe information in the scheduling DCI of the second scheduling step.

Method M300 uses information bit(s) indicating a multiple scheduling method (eg, first information bit) and 'Timing offset' information simultaneously. If multiple scheduling methods are defined in the scheduling of the first scheduling step, the value of the 'Timing offset' field is the mth subframe (e.g., (n+4)th in FIG. 13) that includes the scheduling of the second scheduling step. subframe), it can be defined as indicating the j value of the (m+j)th subframe (e.g., j=1 or 2). In the first scheduling step, information bits (eg, first information bits) indicating multiple scheduling methods may be included in a common DCI or may be included in each uplink scheduling DCI.

If an information bit (e.g., first information bit) indicating a multiple scheduling method is defined (included) in the common DCI, all uplink scheduling of the corresponding subframe may be defined as using a multiple scheduling method. This is because if uplink is scheduled through an existing single scheduling method while multiple scheduling methods are being defined, mutual collisions may occur. Therefore, all uplinks can be scheduled using the same multiple scheduling method.

Alternatively, depending on the information bit (eg, first information bit) indicating the multiple scheduling method, the multiple scheduling method may be applied only to terminals of a designated terminal group. For example, when multiple scheduling methods are specified (indicated) through 2 bits of first information bit, up to 3 terminal groups can be configured. If the group configuration information bit (e.g., first information bit) is included in the DCI for each individual uplink scheduling, different terminal groups are grouped according to the value of the group configuration information bit (e.g., first information bit). This can be specified. When a group configuration information bit (e.g., first information bit) is detected in the scheduling of the second scheduling step, the terminal of the terminal group corresponding to the detected group configuration information bit (e.g., first information bit) is connected to the uplink sub. Frames can be transmitted at a designated time. For example, if a terminal belongs to a terminal group indicated by the group configuration information bit included in the secondary scheduling information, the terminal may transmit an uplink signal at a designated time.

Unlike the method of classifying groups through DCI of individual scheduling, UE group information may be signaled to the UE through a higher-level message (e.g., RRC message). When information bits (eg, group configuration information bits) of terminal group information are included in the common DCI, uplink scheduling of terminals included in the corresponding terminal group may be determined to be multiple scheduling.

DCI (DCI for uplink scheduling) transmitted in a subframe containing information bits (e.g., first information bit) indicating the multiple scheduling method of all or part of the UE group is expected to be scheduled through the multiple scheduling method. It can be. If the information bit (e.g., the first information bit) is included in the scheduling information of the first scheduling step and the same information bit (e.g., the first information bit) is included in the second scheduling information of the second scheduling step , the terminal can transmit uplink according to the scheduling information of the first scheduling step based on the designated transmission time. Secondary scheduling information in the secondary scheduling step may be transmitted and included in the common DCI.

Meanwhile, in a method using PHICH, the PHICH sequence included in the scheduling subframe for the first scheduling step may be transmitted in the same manner in the scheduling subframe for the second scheduling step. The terminal can detect the same PHICH sequence and confirm the scheduling of the first scheduling step and the scheduling of the second scheduling step.

Meanwhile, whether to use multiple scheduling methods may be signaled by an RRC message. When the multiple scheduling method is activated through an RRC message, the uplink subframe scheduled thereafter is defined only through the multiple scheduling method. When multiple scheduling methods are disabled through the RRC message, a single scheduling method becomes possible. When the subframe containing an activation or deactivation message (e.g., RRC message) is the nth subframe, the multiple scheduling method may be defined as being activated or deactivated after the (n+y)th subframe.

Meanwhile, the LBT procedure for uplink channel access scheduled through a multiple scheduling method may follow LBT parameter information signaled through DCI format 0A, DCI format 0B, DCI format 4A, or DCI format 4B. Or, after a downlink subframe or downlink transmission burst (e.g., at least one subframe) for scheduling of the secondary scheduling step, the communication node performs a single sensing of 25us, or empties a gap of 16us and performs sensing. It can be transmitted without.

Meanwhile, the constraints of the multiple scheduling method may be as follows.

For example, the terminal may not receive other uplink scheduling until it transmits the uplink scheduled through the multiple scheduling method. This is because the uplink transmission time based on the multiple scheduling method is not fixed and may conflict with the uplink scheduling of the single scheduling method (eg, fixed to (n+4+k)).

For another example, if the uplink is scheduled through a single scheduling method, the terminal may ignore or initialize scheduling of the previous multiple scheduling method. The terminal may ignore or initialize scheduling of the previous multiple scheduling method based on one of the uplink transmission time based on single scheduling and the time when single scheduling information is confirmed. This is because there may be cases where the terminal fails to detect the secondary scheduling step of multi-scheduling. This is because the base station does not perform single scheduling while performing multiple scheduling for the terminal.

For another example, scheduling of the secondary scheduling stage (eg, secondary scheduling information) is received within a predetermined time (eg, X subframes) from the scheduling point of the primary scheduling stage (eg, n-th subframe). If not, the terminal may ignore or initialize scheduling in the first scheduling step. For example, if secondary scheduling information is not received within a predetermined time (e.g., (invalid) It can be done. Here, the value of X can be signaled to the UE by an RRC message. Alternatively, the value of That is, the value of Alternatively, the value of

Meanwhile, the embodiments of the present invention are not only implemented through the apparatus and/or method described so far, but may also be implemented through a program that realizes the function corresponding to the configuration of the embodiment of the present invention or a recording medium on which the program is recorded. This implementation can be easily implemented by anyone skilled in the art from the description of the above-described embodiments.

Methods according to embodiments of the present invention may be implemented in the form of program instructions that can be executed through various computer means and recorded on a computer-readable medium. Computer-readable media may include program instructions, data files, data structures, etc., singly or in combination. Program instructions recorded on a computer-readable medium may be specially designed and constructed for the present invention, or may be known and usable by those skilled in the art of computer software.

Examples of computer-readable media may include hardware devices specifically configured to store and execute program instructions, such as ROM, RAM, flash memory, and the like. Examples of program instructions may include machine language code such as that created by a compiler, as well as high-level language code that can be executed by a computer using an interpreter or the like. The above-described hardware device may be configured to operate with at least one software module to perform the operations of the present invention, and vice versa.

Although the embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements made by those skilled in the art using the basic concept of the present invention defined in the following claims are also possible. It falls within the scope of rights.

Claims (4)

In a method for a terminal to transmit an uplink signal in an unlicensed band,
A process of receiving downlink control information (DCI) in a downlink subframe from a base station;
A process of determining a sounding reference signal (SRS) transmission location based on the DCI; and
Including the process of transmitting a plurality of uplink subframes including the SRS according to the SRS transmission location,
The SRS is included in the front part of the plurality of uplink subframes and the back part of the plurality of uplink subframes. According to paragraph 1,
At least one uplink subframe among the plurality of uplink subframes includes a clear channel assessment (CCA) section,
A method in which an SRS symbol set is configured in the front part, and the SRS symbol set is configured in a second time domain symbol in the back part. According to paragraph 1,
At least one uplink subframe among the plurality of uplink subframes includes a clear channel assessment (CCA) period and a shortened SRS,
A method in which a plurality of time domain symbols in which PRACH (physical random access channel) and the SRS are multiplexed are configured in the front part, and an SRS symbol set is configured in the back part. In a device where a terminal transmits an uplink signal in an unlicensed band,
memory containing instructions; and
By executing the command, downlink control information (DCI) is received in a downlink subframe from the base station, a sounding reference signal (SRS) transmission location is determined based on the DCI, and the SRS is transmitted according to the SRS transmission location. It includes a processor that transmits a plurality of uplink subframes including,
The SRS is included in the front part of the plurality of uplink subframes and the back part of the plurality of uplink subframes.