KR102498332B1 - Operation method of communication node in network supporting licensed and unlicensed bands - Google Patents

Abstract

A method of operating a communication node in a network supporting licensed and unlicensed bands is disclosed. The method of operation of the UE includes receiving a PDCCH including a DCI from a base station in subframe n-1 of an unlicensed band, decoding the DCI using a common RNTI, and subframe n of the unlicensed band based on the decoded DCI and checking the number of symbols in Thus, the performance of the communication network can be improved.

Description

Method of operating a communication node in a network supporting licensed and unlicensed bands

The present invention relates to a communication technology supporting licensed and unlicensed bands, and more particularly, to a method of operating a communication node supporting licensed assisted access (LAA).

Along with the development of information and communication technology, various wireless communication technologies are being developed. Wireless communication technology is largely classified into wireless communication technology using a licensed band and wireless communication technology using an unlicensed band (eg, industrial scientific medical (ISM) band) according to the band used. It can be. Since the right to use a licensed band is exclusively given to one operator, a wireless communication technology using a licensed band can provide better reliability and communication quality than a wireless communication technology using an unlicensed band.

Representative wireless communication technologies using licensed bands include long term evolution (LTE) and advanced (LTE-A) defined in the 3rd generation partnership project (3GPP) standard. Each of the base station and user equipment (UE) may transmit and receive signals through a licensed band. As a representative wireless communication technology using unlicensed bands, there is a wireless local area network (WLAN) defined in the IEEE 802.11 standard, and each of an access point and station supporting WLAN transmits a signal through an unlicensed band. can transmit and receive.

On the other hand, recently, mobile traffic is explosively increasing, and it is necessary to secure an additional licensed band in order to process such mobile traffic through a licensed band. However, since licensed bands are limited, and usually licensed bands can be secured through a frequency band auction between operators, astronomical costs may be consumed to secure additional licensed bands. In order to solve this problem, a method of providing LTE (or LTE-A, etc.) service through an unlicensed band may be considered.

When an LTE (or LTE-A, etc.) service is provided through an unlicensed band, unnecessary information may be transmitted to a communication node that does not constitute a cell in the unlicensed band. In addition, due to the characteristics of the unlicensed band (eg, opportunistic channel access, limitation of the maximum transmission period (or maximum channel occupancy time), etc.), the subframe structure and scheduling method prescribed for the unlicensed band may not be used in

On the other hand, the background technology of the invention is prepared to enhance understanding of the background of the invention, and may include content other than the prior art already known to those skilled in the art to which the technology belongs.

An object of the present invention to solve the above problems is to provide a method for transmitting control information using a radio network temporary identifier (RNTI) for an unlicensed band.

A method of operating a UE in a communication network according to an embodiment of the present invention for achieving the above object includes receiving a PDCCH including a DCI from a base station in subframe n-1 of an unlicensed band, using a common RNTI Decoding DCI, and determining the number of symbols of subframe n of the unlicensed band based on the decoded DCI.

Here, the common RNTI may be obtained from the base station through RRC signaling.

Here, the CRC of the DCI may be scrambled based on the common RNTI.

Here, the subframe n−1 may have a length of 1ms, and the subframe n may be a partial subframe having a length of less than 1ms.

Here, when consecutive subframes are received from the base station, the subframe n may be a start frame among the consecutive subframes.

Here, when consecutive subframes are received from the base station, the subframe n may be an end subframe among the consecutive subframes.

Here, the operation method of the UE may further include determining whether the subframe n is a partial subframe having a length of less than 1 ms based on the decoded DCI.

A method of operating a base station in a communication network according to another embodiment of the present invention for achieving the above object is generating a DCI including information indicating the number of symbols of subframe n of an unlicensed band, using a common RNTI Performing scrambling on the CRC of the DCI, and transmitting a PDCCH including the scrambled DCI to the UE through subframe n-1 of the unlicensed band.

Here, the common RNTI may be transmitted to the UE through RRC signaling.

Here, the subframe n−1 may have a length of 1ms, and the subframe n may be a partial subframe having a length of less than 1ms.

Here, when consecutive subframes are transmitted to the UE, the subframe n may be a start frame among the consecutive subframes.

Here, when consecutive subframes are transmitted to the UE, the subframe n may be an end subframe among the consecutive subframes.

Here, the DCI may further include information indicating whether the subframe n is a partial subframe having a length of less than 1 ms.

To achieve the above object, a UE supporting an unlicensed band according to another embodiment of the present invention includes a processor and a memory in which at least one instruction executed by the processor is stored, and the at least one instruction is the unlicensed band. Receive a PDCCH including DCI from a base station in subframe n-1 of, decode the DCI using a common RNTI, and determine the number of symbols in subframe n of the unlicensed band based on the decoded DCI Execute do.

Here, the common RNTI may be obtained from the base station through RRC signaling.

Here, the CRC of the DCI may be scrambled based on the common RNTI.

Here, the subframe n−1 may have a length of 1ms, and the subframe n may be a partial subframe having a length of less than 1ms.

Here, when consecutive subframes are received from the base station, the subframe n may be a start frame among the consecutive subframes.

Here, when consecutive subframes are received from the base station, the subframe n may be an end subframe among the consecutive subframes.

Here, the at least one instruction may be further executed to determine whether the subframe n is a partial subframe having a length of less than 1 ms based on the decoded DCI.

According to the present invention, an RNTI for an unlicensed band can be defined. In addition, based on the RNTI for the unlicensed band, subframe structure information (eg, partial subframe related information), scheduling information, activation request information of unlicensed band cells, deactivation request information of unlicensed band cells, etc. can be transmitted . In addition, the UE can obtain only necessary information using the RNTI for the unlicensed band. Accordingly, the unlicensed band cell can be efficiently operated, and the performance of the communication network can be improved.

1 is a conceptual diagram illustrating a first embodiment of a wireless communication network.
2 is a conceptual diagram illustrating a second embodiment of a wireless communication network.
3 is a conceptual diagram illustrating a third embodiment of a wireless communication network.
4 is a conceptual diagram illustrating a fourth embodiment of a wireless communication network.
5 is a block diagram illustrating an embodiment of a communication node constituting a wireless communication network.
6 is a conceptual diagram illustrating an embodiment of a type 1 frame.
7 is a conceptual diagram illustrating an embodiment of a type 2 frame.
8 is a conceptual diagram illustrating an embodiment of a resource grid of slots included in a subframe.
9 is a timing diagram illustrating one embodiment of an unlicensed band burst.
10 is a flowchart illustrating an embodiment of an RRC signaling method for "UE-specific U-RNTI".
11 is a flowchart illustrating a method of transmitting and receiving common control information of an unlicensed band cell.
12 is a timing diagram illustrating a first embodiment of a method for activating an unlicensed band cell.
13 is a timing diagram illustrating a second embodiment of a method for activating an unlicensed band cell.
14 is a timing diagram illustrating a third embodiment of a method for activating an unlicensed band cell.
15 is a timing diagram illustrating a fourth embodiment of a method for activating an unlicensed band cell.
16 is a timing diagram illustrating a fifth embodiment of a method for activating an unlicensed band cell.
17 is a timing diagram illustrating a sixth embodiment of a method for activating an unlicensed band cell.
18 is a timing diagram illustrating a seventh embodiment of a method for activating an unlicensed band cell.
19 is a timing diagram illustrating an eighth embodiment of a method for activating an unlicensed band cell.
20 is a timing diagram illustrating a ninth embodiment of a method for activating an unlicensed band cell.

Since the present invention can make various changes and have various embodiments, specific embodiments are illustrated in the drawings and described in detail. However, this is not intended to limit the present invention to specific embodiments, and should be understood to include all modifications, equivalents, and substitutes included in the spirit and scope of the present invention.

Terms such as first and second may be used to describe various components, but the components should not be limited by the terms. These terms are only used for the purpose of distinguishing one component from another. For example, a first element may be termed a second element, and similarly, a second element may be termed a first element, without departing from the scope of the present invention. The terms and/or include any combination of a plurality of related recited items or any of a plurality of related recited items.

It is understood that when an element is referred to as being "connected" or "connected" to another element, it may be directly connected or connected to the other element, but other elements may exist in the middle. It should be. On the other hand, when an element is referred to as “directly connected” or “directly connected” to another element, it should be understood that no other element exists in the middle.

Terms used in this application are only used to describe specific embodiments, and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly dictates otherwise. In this application, the terms "include" or "have" are intended to designate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, but one or more other features It should be understood that the presence or addition of numbers, steps, operations, components, parts, or combinations thereof is not precluded.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which the present invention belongs. Terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning in the context of the related art, and unless explicitly defined in this application, they should not be interpreted in an ideal or excessively formal meaning. don't

Hereinafter, with reference to the accompanying drawings, preferred embodiments of the present invention will be described in more detail. In order to facilitate overall understanding in the description of the present invention, the same reference numerals are used for the same components in the drawings, and redundant descriptions of the same components are omitted.

In the following, a wireless communication network to which embodiments according to the present invention are applied will be described. A wireless communication network to which embodiments according to the present invention are applied is not limited to the content described below, and embodiments according to the present invention can be applied to various wireless communication networks.

1 is a conceptual diagram illustrating a first embodiment of a wireless communication network.

Referring to FIG. 1 , a first base station 110 is configured for cellular communication (eg, long term evolution (LTE), advanced (LTE-A), and LAA (eg, 3rd generation partnership project (3GPP) standards)). licensed assisted access), etc.). The first base station 110 is multiple input multiple output (MIMO) (eg, single user (SU)-MIMO, multi user (MU)-MIMO, massive MIMO, etc.), coordinated multipoint (CoMP), carrier Aggregation (carrier aggregation; CA) and the like may be supported. The first base station may operate in a licensed band (F1) and may form a macro cell. The first base station 110 may be connected to other base stations (eg, the second base station 120, the third base station 130, etc.) through ideal backhaul or 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 may operate in an unlicensed band (F3) and may 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 may 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 a wireless local area network (WLAN) defined in the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standard. The first base station 110 and each user equipment (UE) (not shown) connected to the first base station 110 transmits and receives signals through carrier aggregation (CA) between the licensed band F1 and the unlicensed band F3 can do.

2 is a conceptual diagram illustrating a second embodiment of a wireless communication network.

Referring to FIG. 2 , each of the first base station 210 and the second base station 220 may support cellular communication (eg, LTE, LTE-A, LAA, etc. specified in the 3GPP standard). 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), and the like. Each of the first base station 210 and the second base station 220 may 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 an ideal backhaul or a non-ideal backhaul. The second base station 220 may be connected to the fourth base station 240 through an ideal backhaul or a 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 may operate in the unlicensed band F3 and 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 may operate in the unlicensed band F3 and form a small cell. Each of the third base station 230 and the fourth base station 240 may support a WLAN defined in the IEEE 802.11 standard. Each of the first base station 210, the UE connected to the first base station 210, the second base station 220, and the UE connected to the second base station 220 are carriers between the licensed band F1 and the unlicensed band F3. Signals may be transmitted and received through aggregation (CA).

3 is a conceptual diagram illustrating a third embodiment of a wireless communication network.

Referring to FIG. 3, each of the first base station 310, the second base station 320, and the third base station 330 uses cellular communication (eg, LTE, LTE-A, LAA, etc. specified in the 3GPP standard). can support The first base station 310, the second base station 320, and the third base station 330 each perform MIMO (eg, SU-MIMO, MU-MIMO, massive MIMO, etc.), CoMP, carrier aggregation (CA), etc. can support 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 other base stations (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 may 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 an ideal backhaul or a 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 may operate in the unlicensed band F3 and form a small cell. The third base station 330 may be connected to the fifth base station 350 through an ideal backhaul or a 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 may operate in the unlicensed band F3 and form a small cell. Each of the fourth base station 340 and the fifth base station 350 may support a WLAN defined in the IEEE 802.11 standard.

A first base station 310, a UE (not shown) connected to the first base station 310, a second base station 320, a UE (not shown) connected to the second base station 320, and a third base station 330 And each UE (not shown) connected to the third base station 330 may transmit and receive signals through carrier aggregation (CA) between the licensed band F1 and the unlicensed band F3.

4 is a conceptual diagram illustrating a fourth embodiment of a wireless communication network.

Referring to FIG. 4 , each of the first base station 410, the second base station 420, and the third base station 430 performs cellular communication (eg, LTE, LTE-A, LAA, etc. specified in the 3GPP standard). can support The first base station 410, the second base station 420, and the third base station 430 each perform MIMO (eg, SU-MIMO, MU-MIMO, massive MIMO, etc.), CoMP, carrier aggregation (CA), etc. can support 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 other base stations (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 may 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 an ideal backhaul or a 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 may operate in the unlicensed band F3 and form a small cell. The third base station 430 may be connected to the fifth base station 450 through an ideal backhaul or a 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 may operate in the unlicensed band F3 and form a small cell. Each of the fourth base station 440 and the fifth base station 450 may support a WLAN defined in the IEEE 802.11 standard.

Each of the first base station 410 and a UE (not shown) connected to the first base station 410 may transmit and receive signals through carrier aggregation (CA) between the licensed band F1 and the unlicensed band F3. The second base station 420, a UE (not shown) connected to the second base station 420, the third base station 430 and a UE (not shown) connected to the third base station 430 each have a licensed band (F2) It is possible to transmit and receive signals through carrier aggregation (CA) between the and unlicensed band (F3).

A communication node (ie, base station, UE, etc.) constituting the above-described wireless communication network may transmit a signal based on a listen before talk (LBT) procedure in an unlicensed band. That is, the communication node may determine the occupancy state 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, the communication node may not transmit a signal when it is determined that the unlicensed band is busy.

Alternatively, the communication node may transmit a signal based on a carrier sensing adaptive transmission (CSAT) operation. That is, the communication node may transmit a signal based on a preset duty cycle. The communication node may transmit a signal if the current duty cycle is an assigned duty cycle for a communication node supporting cellular communication. On the other hand, the communication node may not transmit a signal if the current duty cycle is a duty cycle allocated for a communication node supporting communication (eg, WLAN, etc.) other than cellular communication. The duty cycle may be adaptively determined based on the number of communication nodes supporting the WLAN existing in the unlicensed band, the use state of the unlicensed band, and the like.

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

On the other hand, the communication node is 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) , a single carrier (SC)-FDMA-based communication protocol, an orthogonal frequency division multiplexing (OFDM)-based communication protocol, an orthogonal frequency division multiple access (OFDMA)-based communication protocol, and the like may be supported.

Among communication nodes, a base station is a NodeB (NB), an evolved NodeB (eNB), a base transceiver station (BTS), a radio base station, a radio transceiver, and an access point ; AP), an access node, and the like. Among the communication nodes, the UE includes a terminal, an access terminal, a mobile terminal, a station, a subscriber station, a portable subscriber station, and a mobile station. ), a node, a device, and the like. A communication node may have the following structure.

5 is a block diagram illustrating an embodiment of a communication node constituting a wireless communication network.

Referring to FIG. 5 , a communication node 500 may include at least one processor 510, a memory 520, and a transceiver 530 connected to a network to perform communication. In addition, the communication node 500 may further include an input interface device 540, an output interface device 550, a storage device 560, and the like. Each component included in the communication node 500 is connected by a bus 570 to communicate with each other.

The processor 510 may execute a program command stored in at least one of the memory 520 and the storage device 560 . The processor 510 may mean 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. Each of the memory 520 and the storage device 560 may include at least one of a volatile storage medium and a non-volatile storage medium. For example, the memory 520 may include at least one of read only memory (ROM) and random access memory (RAM).

Next, operating methods of a communication node in a wireless communication network will be described. Even when a method (for example, transmission or reception of a signal) performed in a first communication node among communication nodes is described, a second communication node corresponding thereto is described as a method performed in the first communication node and a method (eg, signal transmission or reception) For example, receiving or transmitting a signal) may be performed. That is, when the operation of the UE is described, the corresponding base station may perform an operation corresponding to the operation of the UE. Conversely, when the operation of the base station is described, the corresponding UE may perform an operation corresponding to that of the base station.

Meanwhile, carrier aggregation may be applied between a cell of an unlicensed band and a cell of a licensed band. Configuration, addition, modification, or release of a cell in an unlicensed band is performed by radio resource control (RRC) signaling (e.g., an RRCConnectionReconfiguration message (hereinafter referred to as “RRC message”) It can be performed through the transmission and reception procedure of)). The RRC message may be transmitted to the UE from a cell in a licensed band. The RRC message may include information necessary for operation and operation of a cell of an unlicensed band.

Signaling of information used in a setup procedure of an initial unlicensed band cell may be performed in a discovery signal measurement timing configuration (DMTC) section. For addition of an unlicensed band cell, a procedure and signaling for selecting a new unlicensed band cell for a UE may be performed. An operating environment of the unlicensed band may be different from that of the licensed band. In this case, procedures and signaling for managing unlicensed band cells may be performed.

Unlike a cell in a licensed band, a section in which a signal can be continuously transmitted in a cell in an unlicensed band may be limited to a maximum transmission section. In addition, when a signal is transmitted based on the LBT, the signal may be transmitted when transmission of another communication node is completed. When LTE (or LTE-A, etc.) service is provided through an unlicensed band, transmission of a communication node supporting LTE (or LTE-A, etc.) may have aperiodic, discontinuous, and opportunistic characteristics. Based on this characteristic, a signal continuously transmitted by a communication node supporting LTE (or LTE-A, etc.) for a certain period of time in an unlicensed band may be referred to as an “unlicensed band burst”.

In addition, channels defined in the licensed band (eg, PCFICH (physical control format indicator channel), PHICH (physical hybrid-ARQ (automatic repeat request) indicator channel), PDCCH (physical downlink control channel), PDSCH (physical downlink shared channel), PMCH (physical multicast channel), PUCCH (physical uplink control channel), PUSCH (physical uplink shared channel), etc.) and signals (eg, synchronization signals, reference signals, etc.) A contiguous set of subframes consisting of one or more combinations may be transmitted through the unlicensed band. In this case, transmission of subframes may be referred to as “unlicensed band transmission”.

A frame used for transmission in an unlicensed band may be classified into a downlink unlicensed band burst frame, an uplink unlicensed band burst frame, and a downlink/uplink unlicensed band burst frame. The downlink unlicensed band burst frame may include a subframe to which “transmission of unlicensed band” is applied, and may further include “unlicensed band signal”. In the downlink unlicensed band burst frame, the "license-exempt band signal" may be located before the subframe to which "unlicensed band transmission" is applied. "Unlicensed band signal" is used to match the timing (or OFDM symbol timing) of a subframe to which "unlicensed band transmission" is applied and the timing (or OFDM symbol timing) of a subframe in a licensed band. can be configured. In addition, the “unlicensed band signal” may be used for automatic gain control (AGC), synchronization acquisition, channel estimation, and the like required for receiving data based on “unlicensed band transmission”.

A subframe to which “unlicensed band transmission” is applied may be set within the maximum transmission interval (or maximum occupation interval). That is, the number of subframes to which "unlicensed band transmission" is applied may be set based on the maximum transmission interval (or maximum occupation interval). At this time, the number of subframes to which "transmission in unlicensed band" is applied may be set in consideration of "unlicensed band signal". The maximum transmission period (or maximum occupancy period) in the unlicensed band may be known through RRC signaling. The UE may check the start time of the "unlicensed band burst" by detecting the PDCCH (or EPDCCH) or "unlicensed band signal". Actual occupancy time by a subframe to which "unlicensed band burst" or "unlicensed band transmission" is applied may be known through "unlicensed band signal" or PHICH.

"Unlicensed band signal" may include information (or sequence) indicating the number (or time) of subframes used for "unlicensed band burst" or "license-exempt band transmission". Alternatively, information (or sequence) indicating the number (or time) of subframes used for “unlicensed band burst” or “unlicensed band transmission” may be transmitted through the PHICH.

Transmission of HARQ-related information for uplink in an unlicensed band may be performed asynchronously differently from a licensed band. Therefore, RV and HARQ process numbers may be transmitted through PDCCH (or EPDCCH) instead of PHICH. In this case, PHICH may be used for transmission of other information. For example, information (or sequence) indicating the number (or time) of subframes used for “unlicensed band burst” or “license-exempt band transmission” may be transmitted through the PHICH.

Meanwhile, a cellular communication network (eg, an LTE network) may support a frequency division duplex (FDD) scheme, a time division duplex (TDD) scheme, and the like. A frame based on the FDD scheme may be defined as a "type 1 frame", and a frame based on the TDD scheme may be defined as a "type 2 frame".

6 is a conceptual diagram illustrating an embodiment of a type 1 frame.

Referring to FIG. 6 , a radio frame 600 may include 10 subframes, and each subframe may include 2 slots. Accordingly, the radio frame 600 may include 20 slots (eg, slot #0, slot #1, slot #2, slot #3, ..., slot #18, slot #19). The length of the radio frame 600 (T _f ) may be 10 ms. The subframe length may be 1 ms. The slot length (T _slot ) may be 0.5 ms. Here, T _s may be 1/30,720,000s.

A slot may consist of a plurality of OFDM symbols in the time domain and may consist of a plurality of resource blocks (RBs) in the frequency domain. A resource block may be composed of a plurality of subcarriers in the frequency domain. The number of OFDM symbols constituting a slot may vary depending on the configuration of a cyclic prefix (CP). CP can be classified into normal CP and extended CP. If a regular CP is used, a slot may consist of 7 OFDM symbols, and in this case, a subframe may consist of 14 OFDM symbols. If the extended CP is used, a slot may consist of 6 OFDM symbols, and in this case, a subframe may consist of 12 OFDM symbols.

For example, when a subframe is composed of 14 OFDM symbols, the respective numbers of OFDM symbols constituting the subframe are sequentially OFDM symbol #0, OFDM symbol #1, OFDM symbol #2, and OFDM symbols in the time domain. Symbol #3, OFDM Symbol #4, OFDM Symbol #5, OFDM Symbol #6, OFDM Symbol #7, OFDM Symbol #8, OFDM Symbol #9, OFDM Symbol #10, OFDM Symbol #11, OFDM Symbol #12, OFDM It may be referred to as symbol #13.

7 is a conceptual diagram illustrating an embodiment of a type 2 frame.

Referring to FIG. 7 , a radio frame 700 may include two half frames, and each half frame may include 5 subframes. Accordingly, the radio frame 700 may include 10 subframes. The length of the radio frame 700 (T _f ) may be 10 ms. The length of the half frame may be 5 ms. The subframe length may be 1 ms. Here, T _s may be 1/30,720,000s.

The radio frame 700 may include a downlink subframe, an uplink subframe, and a special subframe. Each of the downlink subframe and the uplink subframe may include two slots. The slot length (T _slot ) may be 0.5 ms. Among the subframes included in the radio frame 700, each of subframe #1 and subframe #6 may be a special subframe. The special subframe may include a downlink pilot time slot (DwPTS), a guard period (GP), and an uplink pilot time slot (UpPTS).

The downlink pilot time slot may be regarded as a downlink period and may be used for cell search, time and frequency synchronization acquisition of the UE, and the like. The guard period may be used to solve an interference problem of uplink data transmission caused by a downlink data reception delay. In addition, the guard period may include a time required for switching from a downlink data reception operation to an uplink data transmission operation. The uplink pilot time slot may be used for uplink channel estimation, time and frequency synchronization acquisition, and the like.

Lengths of each of the downlink pilot time slot, guard period, and uplink pilot time slot included in the special subframe may be variably adjusted as needed. In addition, the number and position of each of downlink subframes, uplink subframes, and special subframes included in the radio frame 700 may be changed as needed.

8 is a conceptual diagram illustrating an embodiment of a resource grid of slots included in a subframe.

Referring to FIG. 8, when a regular CP is used, a resource block of a slot included in a downlink subframe or an uplink subframe may consist of 7 OFDM symbols in the time domain and 12 subframes in the frequency domain. It can consist of carriers. In this case, a resource composed of one OFDM symbol in the time domain and one subcarrier in the frequency domain may be referred to as a "resource element (RE)".

In downlink transmission of a cellular communication network (eg, LTE network), resource allocation for one UE may be performed in units of resource blocks, and mapping for reference signals, synchronization signals, etc. is performed in units of resource elements. can be performed

A control channel is assigned to three OFDM symbols (eg, OFDM symbols #0 to #2) or four OFDM symbols (eg, OFDM symbols #0 to #3) located in the front part of the first slot of the subframe. can be configured. Control channels may include PDCCH, PCFICH, PHICH, and the like. A data channel (eg, PDSCH, etc.) used for data transmission in the remaining regions (eg, OFDM symbol # 4 to OFDM symbol # 13) other than the region in which the control channel is configured in the subframe may be configured by default, , EPDCCH may be configured in some resource blocks (or resource elements) among the remaining regions.

Information indicating the number of OFDM symbols used for the control channel may be transmitted through the PCFICH. PCFICH may be configured in OFDM symbol #0 of a subframe. A response (eg, a hybrid automatic repeat request (HARQ) response, etc.) to an uplink (eg, PUSCH, etc.) transmission may be transmitted through the PHICH. Here, the HARQ response may include acknowledgment (ACK), negative ACK (NACK), discontinuous transmission (DTX), ANY, and the like.

Downlink control information (DCI) may be transmitted through at least one of a PDCCH and an EPDCCH. The DCI may include at least one of resource allocation information and resource control information for the UE and a specific group. For example, the DCI may include downlink scheduling information, uplink scheduling information, and an uplink transmit power control command. Here, a specific group may include at least one UE.

DCI may have different formats depending on the type, number, and size (eg, number of bits constituting the information field) of information fields. DCI formats 0, 3, 3A, 4, etc. may be used for uplink. DCI formats 1, 1A, 1B, 1C, 1D, 2, 2A, 2B, 2C, etc. may be used for downlink. Information included in the DCI may vary according to the DCI format. For example, carrier indicator field (CIF), resource block allocation, modulation and coding scheme (MCS), redundancy version (RV), new data indicator (NDI), transmit power control (TPC), HARQ process number, Information such as a precoding matrix indicator (PMI) (or PMI confirmation), a hopping flag, and a flag field may be selectively included in the DCI according to the DCI format. Accordingly, the size of control information may vary according to the DCI format. Also, the same DCI format may be used to transmit two or more types of control information. In this case, control information may be distinguished by a flag field included in DCI. Control information included in DCI for each DCI format may be shown in Table 1 below.

The PDCCH may be allocated to an aggregation of one or a plurality of contiguous control channel elements (CCEs), and the EPDCCH may be allocated to an aggregation of one or a plurality of contiguous enhanced CCEs (ECCEs). A CCE or ECCE may be a logical allocation unit and may be composed of a plurality of resource element groups (REGs). The size of bits transmitted through the PDCCH (or EPDCCH) may be determined based on the number of CCEs (or ECCEs), code rate, and the like.

9 is a timing diagram illustrating one embodiment of an unlicensed band burst.

Referring to FIG. 9 , timing of a subframe (or slot, OFDM symbol, etc.) of a licensed band may be the same as timing of a subframe (or slot, OFDM symbol, etc.) of an unlicensed band. In the licensed band, signals can be continuously transmitted. That is, burst transmission may occur continuously in the licensed band.

On the other hand, burst transmission in an unlicensed band may occur discontinuously. For example, an unlicensed band burst may be generated in units of 4 subframes. Among the subframes constituting the unlicensed band burst, a start subframe (ie, a first subframe) may have a size smaller than 1 ms. A start subframe having a size smaller than 1 ms may be referred to as a "start subframe". In addition, among the subframes constituting the unlicensed band burst, an end subframe (ie, the last subframe) may have a size smaller than 1 ms. An ending subframe having a size smaller than 1 ms may be referred to as an "end partial subframe". The sum of the length of the start subframe and the length of the end subframe may be set to 1 ms. For example, the start subframe may consist of OFDM symbols #4 of the first slot to OFDM symbol #6 of the second slot, and in this case, the end subframe may consist of OFDM symbols #0 to # of the first slot. It can consist of 3.

The starting point of the unlicensed band burst (or the beginning subframe) may be set within a preset set of OFDM symbol numbers. For example, the start time of the unlicensed band burst may be set to OFDM symbol #0 of the first slot or OFDM symbol #0 of the second slot in the subframe. Alternatively, in a TDD-based network, the start time of an unlicensed band burst may be an OFDM symbol located after “OFDM symbol #0 of the first slot + a preset offset” within a subframe. Here, the preset offset may be a time corresponding to "Guard Period (GP) + Uplink Pilot Time Slot (UpPTS)". For example, in a TDD-based network, the start time of an unlicensed band burst may be OFDM symbol #0, #2, #3, or #5 of a first slot in a subframe, or OFDM symbol #1 of a second slot. .

Alternatively, the start time of the unlicensed band burst may be set to a start time, an end time, or a transmission time of a reference signal (eg, cell specific reference signal (CRS), etc.) of a PDCCH in a licensed band. For example, the start time of the unlicensed band burst may be OFDM symbol #0 or #4 of the first slot in the subframe. The start time of the unlicensed band burst is not limited to the above description, and may be set to any OFDM symbol within the subframe.

Meanwhile, a cyclic redundancy check (CRC) for error detection may be attached to control information transmitted through PDCCH (or EPDCCH) based on the DCI format. The CRC is masked (eg, scrambling) based on a radio network temporary identifier (RNTI) according to a communication node (eg, UE, station, etc.) to receive PDCCH (or EPDCCH). can Alternatively, the CRC may be masked (eg, scrambled) based on the RNTI according to the purpose. Types of RNTI and corresponding values may be shown in Table 2 below.

The use of RNTI may be as shown in Table 3 below.

The unlicensed band cell related identifier may be referred to as an unlicensed cell (U)-RNTI, and may be referred to differently according to information of an unlicensed band cell. U-RNTI may be transmitted to the UE through RRC signaling.

)는 아래 수학식 1을 기초로 결정될 수 있다. UE는 PDCCH(또는, EPDCCH)를 획득하기 위해 후보 CCE(또는, ECCE)를 모니터링할 수 있다.A PDCCH (or EPDCCH) including a CRC masked (eg, scrambled) with a U-RNTI may be transmitted through a common search space or a UE-specific search space. can The location of the PDCCH (or EPDCCH) in the common search space or the UE-specific search space is the aggregation level of the CCE (or ECCE) and the CCE (or ECCE) index calculated by the U-RNTI etc. can be determined. The location of the candidate CCE (or ECCE) to be monitored in the common search space or UE-specific search space (

) may be determined based on Equation 1 below. The UE may monitor the candidate CCE (or ECCE) to obtain the PDCCH (or EPDCCH).

L may indicate an aggregation level. For example, L can be 1, 2, 4 or 8. The aggregation level for the CCE (or ECCE) included in the PDCCH (or EPDCCH) transmitted in the partial subframe (eg, subframe having a length of less than 1 ms) of the unlicensed band is a value greater than 8 (eg For example, 16, 32, etc.). In the common search space, Y _k may be set to 0. In addition, Y _k may be determined based on RNTI (eg, U-RNTI in an unlicensed band). m' may be a positive integer smaller than the total number (M ^(L) -1) of candidate PDCCHs (or candidate EPDCCHs, candidate CCEs, and candidate ECCEs) to be monitored in the common search space (or UE-specific search space). . N _CCE,k may indicate the total number of CCEs (or ECCEs) included in subframe k.

Meanwhile, the U-RNTI may be set to a UE-specific value, a common value for a base station, a common value for an unlicensed band cell, a reserve value, and the like. A U-RNTI having a value for UE-specificity may be referred to as "UE-specific U-RNTI". A U-RNTI having a common value for base stations may be referred to as "base station common U-RNTI". A U-RNTI having a common value for unlicensed band cells may be referred to as "unlicensed band cell common U-RNTI". "Base station common U-RNTI" and "unlicensed band cell common U-RNTI" may be used for transmission of common control information.

"UE-specific U-RNTI" may be transmitted through RRC signaling together with information related to configuration, addition, etc. of an unlicensed band cell. An RRC signaling method for "UE-specific U-RNTI" may be as follows.

10 is a flowchart illustrating an embodiment of an RRC signaling method for "UE-specific U-RNTI".

Referring to FIG. 10 , a base station and a UE may form the wireless communication network described with reference to FIGS. 1 to 4 and may support a licensed band and an unlicensed band. A base station may support carrier aggregation. The base station and UE may be configured identically or similarly to the communication node 500 described with reference to FIG. 5 . Subframe (or slot, OFDM symbol, etc.) timing of the licensed band may be the same as subframe (or slot, OFDM symbol, etc.) timing of the unlicensed band.

The base station may generate an RRC message (eg, RRCConnectionReconfiguration message) including "UE-specific U-RNTI" (or "base station common U-RNTI", "unlicensed band cell common U-RNTI") ( S1000). The base station may transmit an RRC message (S1010). The RRC message may be transmitted in a licensed band or an unlicensed band. The UE may receive an RRC message from the base station, and obtain a "UE-specific U-RNTI" (or "base station common U-RNTI", "unlicensed band cell common U-RNTI") from the received RRC message. It can (S1020). When the RRC message is received, the UE may transmit a response message (eg, RRCConnectionReconfigurationComplete message) to the base station in response to the RRC message (S1030).

On the other hand, "base station common U-RNTI" may be used for transmission of system information and configuration related information of an unlicensed band cell set by the base station. Configuration-related information and system information of an unlicensed band cell may be referred to as "UCell configuration/system information". The “base station common U-RNTI” may be preset identically or similarly to the SI-RNTI. Alternatively, "base station common U-RNTI" may be transmitted through RRC signaling. "Unlicensed band cell common U-RNTI" may be set for each unlicensed band cell. "Unlicensed band cell common U-RNTI" may be transmitted through RRC signaling. For example, in a procedure in which an unlicensed band cell is newly configured as a secondary cell (SCell), "unlicensed band cell common U-RNTI" may be included in an RRC message (eg, an RRCConnectionReconfiguration message).

The U-RNTI may be used for transmission of unlicensed band related information supported by the base station (eg, information related to configuration/addition/modification/release of unlicensed band cells, system information, etc.). In addition, U-RNTI may be used to transmit control information of different unlicensed band cells. In addition, the U-RNTI may be used for transmission of a dynamic activation or deactivation request message of an unlicensed band cell. Here, the U-RNTI may be set differently depending on the purpose and the reception target of the PDCCH (or EPDCCH). For example, a U-RNTI used for transmission of an activation or deactivation message of a common unlicensed band cell may be configured. Alternatively, a U-RNTI used for transmission of an activation or deactivation message of a UE-specific unlicensed band cell may be configured.

U-RNTI related information (eg, U-RNTI value, period, etc.) used for transmission of UCell configuration/system information may be signaled by RRC. Scheduling information for UCell configuration/system information may be transmitted through a PDCCH (or EPDCCH) within a common search space in a licensed band cell (eg, licensed band primary cell (PCell) or licensed band SCell). UCell configuration/system information may be transmitted through PDSCH indicated by scheduling information. The CRC of DCI including scheduling information, control information, etc. for UCell configuration/system information may be masked (eg, scrambled) with U-RNTI. UCell configuration/system information may be transmitted periodically or aperiodically. When UCell configuration/system information is transmitted periodically, information indicating a transmission period may be transmitted through RRC signaling. In this case, the UE may obtain information indicating a transmission period through RRC signaling, receive PDCCH (or EPDCCH) based on the transmission period, and use U-RNTI to transmit PDCCH (or EPDCCH) UCell configuration/system information can be obtained from

The UCell configuration/system information may include at least one of unlicensed band related information supported by the base station, operation/management related information of the unlicensed band cell, and UE requirements related to the unlicensed band cell. For example, the UCell configuration/system information includes channel information of an unlicensed band supported by the base station, maximum transmit power, channel access method (eg, channel access method based on LBT operation, etc.), maximum transmission period, and maximum channel occupancy Time, information related to channel state measurement (eg, measurement time and period of received signal strength (eg, received signal strength indication (RSSI)), RSSI histogram, etc.), multicast broadcast (MBSFN) in unlicensed band cells configuration information of a subframe for a single frequency network), configuration information of a start subframe included in an unlicensed band burst (eg, information indicating whether the start subframe is a partial subframe, OFDM constituting the start subframe) Number of symbols, OFDM symbol number (or set of OFDM symbol numbers) where the start subframe starts, etc.) and configuration information of the end subframe included in the unlicensed band burst (eg, whether the end subframe is a partial subframe) It may include at least one of information indicating whether or not, the number of OFDM symbols constituting the ending subframe, the OFDM symbol number (or set of OFDM symbol numbers) where the ending subframe ends, etc.). UCell configuration/system information may be transmitted to the UE through an RRC message.

If the UCell configuration/system information includes configuration information of a start subframe included in the unlicensed band burst, the set of OFDM symbol numbers at which the start subframe starts may be {3, 6} or {0, 3, 6} there is. Here, OFDM symbol #7 may be used instead of OFDM symbol #6.

If the UCell configuration/system information includes the configuration information of the end subframe included in the unlicensed band burst, the set of OFDM symbol numbers at which the end subframe ends is {3, 9, 10, 11, 12}, {9, 10, 11, 12}, {3, 9, 10, 11, 12, 13} or {9, 10, 11, 12, 13}. When a type 2 frame is used, a set of OFDM symbol numbers may be set according to the DwPTS configuration. Alternatively, a set of OFDM symbol numbers may be set regardless of the DwPTS configuration.

Meanwhile, a UE (eg, a UE to configure an unlicensed band cell) may obtain configuration-related information of an unlicensed band cell by receiving UCell configuration/system information. The UE may configure the unlicensed band cell using configuration-related information of the unlicensed band cell. Here, since the UCell configuration/system information is transmitted based on the U-RNTI instead of the SI-RNTI, all UEs do not need to perform reception and decoding operations of the PDSCH including the UCell configuration/system information. For example, a UE that does not configure an unlicensed band cell may not use a U-RNTI. Therefore, a UE not configuring an unlicensed band cell cannot decode a PDCCH (or EPDCCH) including scheduling information for UCell configuration/system information, and may not receive a PDSCH including UCell configuration/system information. . On the other hand, a UE that wants to configure an unlicensed band cell may receive a DCI including a CRC masked (eg, scrambled) with a U-RNTI through a PDCCH (or EPDCCH) of a common search space, and U-RNTI Scheduling information for UCell configuration/system information may be obtained by performing descrambling on DCI based on . A UE desiring to configure an unlicensed band cell may receive UCell configuration/system information through a PDSCH indicated by scheduling information. Here, the CRC of the PDSCH including the UCell configuration/system information may be masked (eg, scrambled) based on the U-RNTI. In this case, the UE may obtain UCell configuration/system information by performing descrambling based on the U-RNTI.

Next, a use case of "unlicensed band cell common U-RNTI" will be described. "Unlicensed band cell common U-RNTI" may be set for each unlicensed band cell. "Unlicensed band cell common U-RNTI" related information (eg, U-RNTI value, period, etc.) may be transmitted through RRC signaling. For example, information related to "unlicensed band cell common U-RNTI" may be transmitted through an RRCConnectionReconfiguration message. Alternatively, information related to "unlicensed band cell common U-RNTI" may be included in UCell configuration/system information.

"Unlicensed band cell common U-RNTI" may be used for transmission of control information for each unlicensed band cell in a licensed band cell or an unlicensed band cell. For example, for transmission of UCell configuration/system information for unlicensed band Cell-A, “unlicensed band cell common U-RNTI” configured for unlicensed band Cell-A may be used. The CRC of the PDCCH (or EPDCCH) including scheduling information for the UCell configuration / system information for the unlicensed band cell-A is masked based on the “unlicensed band cell common U-RNTI” configured for the unlicensed band cell-A ( e.g. scrambling). The CRC of the PDSCH containing the UCell configuration/system information for the unlicensed band cell-A may be masked (eg, scrambled) based on the "unlicensed band cell common U-RNTI" configured for the unlicensed band cell-A. . Accordingly, the UE may obtain UCell configuration/system information for the unlicensed band Cell-A by performing descrambling based on the "unlicensed band cell common U-RNTI" configured for the unlicensed band Cell-A.

Control information for each unlicensed band cell may be transmitted periodically or aperiodically. When the control information for each unlicensed band cell is transmitted periodically, the period information on the control information for each unlicensed band cell may be transmitted through RRC signaling. Alternatively, a discovery reference signal (DRS) periodically transmitted in the unlicensed band may include control information for each cell in the unlicensed band. In this case, the control information for each unlicensed band cell may be transmitted periodically according to the DRS cycle. In addition, the CRC of the PDCCH (or EPDCCH, PDSCH) in which the DRS is configured may be masked (eg, scrambled) based on the "unlicensed band cell common U-RNTI". Accordingly, the UE may obtain control information for each unlicensed band cell by performing descrambling based on the "unlicensed band cell common U-RNTI".

The control information for each unlicensed band cell may include at least one of unlicensed band related information supported by the base station, operation/management related information of the unlicensed band cell, and UE requirements related to the unlicensed band cell. For example, the UCell unlicensed band cell-specific control information includes channel information of the unlicensed band supported by the base station, maximum transmission power, channel access method (eg, channel access method based on LBT operation, etc.), maximum transmission period, maximum channel It may include at least one of occupancy time and channel state measurement-related information (eg, measurement time and period of received signal strength (eg, RSSI), RSSI histogram, etc.).

Meanwhile, a UE configuring an unlicensed band cell may obtain control information for each unlicensed band cell through PDCCH (or EPDCCH, PDSCH). For example, the UE may obtain control information for each unlicensed band cell by performing descrambling on PDCCH (or EPDCCH, PDSCH) based on "unlicensed band cell common U-RNTI". Accordingly, only the UE configuring the unlicensed band cell (eg, the UE using the "unlicensed band cell common U-RNTI") can obtain the control information for each unlicensed band cell.

In addition, "unlicensed band cell common U-RNTI" may be used for transmission of common control information of unlicensed band cells. Alternatively, "unlicensed band cell common U-RNTI" may be used to transmit DCI through a PDCCH (or EPDCCH) in a common search space of an unlicensed band. Here, DCI may be transmitted through common signaling. "Unlicensed band cell common U-RNTI" may be set identically in all cells of the unlicensed band. Alternatively, "Unlicensed band cell common U-RNTI" may be set differently for each unlicensed band cell. When the "unlicensed band cell common U-RNTI" is set differently for each unlicensed band cell, the "unlicensed band cell common U-RNTI" may be transmitted to the UE through an RRC message.

When the SCell is configured in the unlicensed band, DCI including common control information of the unlicensed band cell may be transmitted through PDCCH (or EPDCCH) in the common search space of the unlicensed band SCell. Therefore, the UE can receive the PDCCH (or EPDCCH) by monitoring the common search space in the unlicensed band SCell. To reduce the number of blind detections for PDCCH (or EPDCCH) monitoring, a fixed aggregation level or fixed DCI format may be used. For example, the aggregation level may be 4 or 8. DCI format can be 1A or 1C. The common control information of the unlicensed band cell may include at least one of the following information.

- Information indicating whether a subframe (hereinafter referred to as "current subframe") including common control information of an unlicensed band cell is a start subframe among unlicensed band bursts (eg, a set of consecutive subframes)

-Information indicating whether the current subframe is an end subframe among unlicensed band bursts

- Information indicating whether the current subframe is a partial subframe

- Information indicating the number of OFDM symbols included in the current subframe

- Information indicating the OFDM symbol number (or set of OFDM symbol numbers) where the current subframe starts

- Information indicating the OFDM symbol number (or set of OFDM symbol numbers) at which the current subframe ends

- Information indicating the CRS port of the current subframe

- Information indicating the number of OFDM symbols configured with CRS in the current subframe

- MBSFN-related information in the current subframe

-Information indicating the number of subframes continuously configured after the current subframe

-Information indicating whether the current subframe consists only of DRS

- Information indicating transmission power of a reference signal (eg, CRS, channel state information (CSI)-RS, etc.) in the current subframe or unlicensed band burst

- Information indicating the transmission power offset of a reference signal (eg, CRS, CSI-RS, etc.) in the current subframe or unlicensed band burst

- Information indicating whether a subframe located after the current subframe (hereinafter referred to as "next subframe") is a partial subframe

- Information indicating the number of OFDM symbols included in the next subframe

- Information indicating the OFDM symbol number (or set of OFDM symbol numbers) where the next subframe starts

- Information indicating the OFDM symbol number (or set of OFDM symbol numbers) at which the next subframe ends

Meanwhile, a method of transmitting and receiving common control information of an unlicensed band cell may be as follows.

11 is a flowchart illustrating a method of transmitting and receiving common control information of an unlicensed band cell.

Referring to FIG. 11 , a base station and a UE may form the wireless communication network described with reference to FIGS. 1 to 4 and may support a licensed band and an unlicensed band. A base station may support carrier aggregation. The base station and UE may be configured identically or similarly to the communication node 500 described with reference to FIG. 5 . Subframe (or slot, OFDM symbol, etc.) timing of the licensed band may be the same as subframe (or slot, OFDM symbol, etc.) timing of the unlicensed band.

The base station may generate DCI including information indicating the number of OFDM symbols of subframe #(n-1) or subframe #n (S1100). In addition, the DCI may further include information indicating whether subframe #(n-1) or subframe #n is a partial subframe. Subframe #(n-1) or subframe #n may be a start subframe among a plurality of subframes included in the unlicensed band burst. For example, when subframe #n is a starting subframe among a plurality of subframes included in the unlicensed band burst, subframe #(n-1) may be a subframe located before the unlicensed band burst. In this case, the length of subframe #(n-1) may be 1ms, and the length of subframe #n may be less than 1ms. That is, subframe #n may be a partial subframe. When subframe #(n-1) is a starting subframe among a plurality of subframes included in the unlicensed band burst, subframe #n is a subframe located after subframe #(n-1) in the unlicensed band burst. can In this case, the length of subframe #(n-1) may be less than 1ms, and the length of subframe #n may be 1ms. That is, subframe #(n-1) may be a partial subframe.

Alternatively, subframe #(n-1) or subframe #n may be an end subframe among a plurality of subframes included in the unlicensed band burst. For example, when subframe #n is the last subframe among a plurality of subframes included in the unlicensed band burst, subframe #(n-1) may be a subframe located before subframe #n in the unlicensed band burst. there is. In this case, the length of subframe #(n-1) may be 1ms, and the length of subframe #n may be less than 1ms. That is, subframe #n may be a partial subframe. When subframe #(n-1) is the last subframe among a plurality of subframes included in the unlicensed band burst, subframe #n may be a subframe located after the unlicensed band burst. In this case, the length of subframe #(n-1) may be less than 1ms, and the length of subframe #n may be 1ms. That is, subframe #(n-1) may be a partial subframe.

The base station may perform masking (eg, scrambling) on the CRC of the DCI using the RNTI (S1110). The RNTI may be transmitted to the UE through RRC signaling. The RNTI may be a C-RNTI or a U-RNTI (eg, "UE-specific U-RNTI", "base station common U-RNTI", "unlicensed band cell common U-RNTI", etc.).

The base station may transmit a PDCCH (or EPDCCH) including scrambled DCI in subframe #(n-1) of the unlicensed band (S1120). The UE may receive a PDCCH (or EPDCCH) including the scrambled DCI from the base station in subframe #(n-1) of the unlicensed band. The UE may perform decoding / descrambling on DCI included in the PDCCH (or EPDCCH) using the RNTI (S1130). The UE may check the number of OFDM symbols of subframe #(n-1) or subframe #n based on the decoded/descrambled DCI (S1140). In addition, the UE may check whether subframe #(n-1) or subframe #n is a partial subframe based on the decoded/descrambled DCI.

Meanwhile, U-RNTI may be used for activation or deactivation of an unlicensed band cell. A U-RNTI used for activation of an unlicensed band cell may be referred to as "activation U-RNTI". A U-RNTI used for deactivation of an unlicensed band cell may be referred to as "deactivation U-RNTI". "Activation U-RNTI" and "deactivation U-RNTI" may be transmitted to the UE through RRC signaling. For example, “Activation U-RNTI” and “Deactivation U-RNTI” may be included in “UCell configuration/system information”. Therefore, the UE can check the "activation U-RNTI" and "deactivation U-RNTI" by receiving the "UCell configuration/system information". In addition, "Activation U-RNTI" and "Deactivation U-RNTI" may be included in control information related to an unlicensed band cell used for the "RRCConnectionReconfiguration" procedure. Therefore, the UE can check the "Activation U-RNTI" and "Deactivation U-RNTI" by performing the "RRCConnectionReconfiguration" procedure.

The "activation U-RNTI" may be the same as or similar to the "deactivation U-RNTI". "Activation U-RNTI (or deactivation U-RNTI)" may be set for each unlicensed band cell. In this case, "Activation U-RNTI (or Deactivation U-RNTI)" may be used to request activation (or deactivation) of an unlicensed band cell to all UEs belonging to a specific unlicensed band cell. A PDCCH (or EPDCCH) including a CRC masked (eg, scrambled) with an "active U-RNTI (or inactive U-RNTI)" configured for a specific unlicensed band cell is a common search space or UE-specific search can be transmitted in space. Here, the UE-specific search space may be indicated by a CCE (or ECCE) index defined according to “activation U-RNTI (or deactivation U-RNTI)”.

"Activation U-RNTI (or inactivation U-RNTI)" may be set for each UE. For example, "Activation U-RNTI (or Deactivation U-RNTI)" may be set for a specific UE among UEs belonging to an unlicensed band cell for which activation (or deactivation) is required. "Activation U-RNTI (or inactivation U-RNTI)" configured for a specific UE may be transmitted to the specific UE through RRC signaling. A PDCCH (or EPDCCH) including a CRC masked (eg, scrambled) with an “active U-RNTI (or inactive U-RNTI)” set for a specific UE may be transmitted in a UE-specific search space. . Here, the UE-specific search space may be indicated by a CCE (or ECCE) index defined according to “activation U-RNTI (or deactivation U-RNTI)”. Therefore, the UE can receive the PDCCH (or EPDCCH) using the "Activation U-RNTI (or Deactivation U-RNTI)" in the UE-specific search space candidates, and the received PDCCH (or EPDCCH) An unlicensed band cell may be activated (or deactivated) based on the indicated information.

The “Activation U-RNTI (or Deactivation U-RNTI)” and the C-RNTI allocated per UE may be masked (eg, scrambled) to the CRC at the same time. A PDCCH (or EPDCCH) based on C-RNTI and modulo 2 of "Activation U-RNTI (or Deactivation U-RNTI)" may be transmitted in a UE-specific search space. CCE (or ECCE) index for transmission of PDCCH (or EPDCCH) is calculated using C-RNTI or C-RNTI and a value based on modulus 2 of "Activation U-RNTI (or Deactivation U-RNTI)" It can be. The UE selects "activation U-RNTI (or deactivation U-RNTI)" in UE-specific search space candidates indicated by a value based on C-RNTI and modulo 2 of "activation U-RNTI (or deactivation U-RNTI)" A PDCCH (or EPDCCH) may be received using ", and an unlicensed band cell may be activated (or deactivated) based on information indicated by the received PDCCH (or EPDCCH).

On the other hand, when a PDCCH (or EPDCCH) including a CRC masked (eg, scrambled) with “active U-RNTI (or deactivated U-RNTI)” is received in subframe #n, the UE From #(n+k), unlicensed band cells can be activated (or deactivated). k may be an integer greater than or equal to 1. For example, k can be 2, 4, 8, etc. k may be preset in the base station and the UE as a fixed value. Alternatively, k may be transmitted to the UE through RRC signaling. Alternatively, DCI may include a new field indicating k, and DCI may be transmitted to the UE through PDCCH (or EPDCCH). Alternatively, k may be set based on UE capability (eg, reception/decoding capability), in which case k is a reporting procedure for UE capability information (or unlicensed band cell-related It may be transmitted through a transmission procedure of a response to RRC signaling).

Information transmitted through the RRC message (or RRC signaling) defined for the U-RNTI described above may be included in a new system information block (SIB) for the unlicensed band cell. A new SIB for an unlicensed band cell may be transmitted periodically. In this case, U-RNTI or SI-RNTI may be used.

Next, a method of activating and deactivating a licensed band cell will be described.

Activation and deactivation of the secondary cell of the licensed band may be performed based on an activation/deactivation medium access control (MAC) control element (MAC CE). When the index of the secondary cell of the licensed band is set to 0 in the activation/deactivation MAC CE, this may indicate that the secondary cell of the licensed band operates in an inactive state. On the other hand, when the index of the secondary cell of the licensed band is set to 1 in the activation/deactivation MAC CE, this may indicate that the secondary cell of the licensed band operates in an active state.

In addition, activation and deactivation of the secondary cell of the licensed band may be performed based on the time indicated by the SCell deactivation time field included in the RRC message. The SCell deactivation time field may indicate 20 ms, 40 ms, 80 ms, 160 ms, 320 ms, 640 ms, 1280 ms, and the like. For example, when the time indicated by the SCell deactivation time field elapses, the state of the secondary cell of the licensed band may be switched from an active state to an inactive state. If the SCell deactivation time field is not set, this may mean that the SCell deactivation time field indicates infinity time. The time indicated by the SCell deactivation time field may be applied to all secondary cells of the licensed band.

For example, when activation/deactivation MAC CE indicating activation of the secondary cell of the licensed band is received in subframe #n, the UE may activate the secondary cell of the licensed band, and in subframe #(n+8) The timer may be activated (or reactivated) based on the time indicated by the SCell deactivation time field. After that, the UE receives a PDCCH (or EPDCCH) for uplink or downlink scheduling (eg, self scheduling or cross carrier scheduling) for the secondary cell of the activated licensed band. In this case, the timer may be reactivated based on the time indicated by the SCell deactivation time field. When an activation/deactivation MAC CE indicating deactivation of the secondary cell of the licensed band is received or the time indicated by the SCell deactivation time field has elapsed, the UE may deactivate the secondary cell of the licensed band. In this case, the UE may deactivate the secondary cell of the licensed band before subframe #(n+8).

Meanwhile, activation and deactivation of the unlicensed band cell may be performed based on the activation/deactivation MAC CE and the SCell deactivation time field. If the unlicensed band is occupied by another communication node, the UE shall wait until the time indicated by the SCell deactivation time field elapses (eg, until the state of the unlicensed band cell transitions from active state to inactive state). PDCCH (or EPDCCH) may not be received. In this case, re-activation of the unlicensed band cell may be required. To solve this problem, activation and deactivation of unlicensed band cells may be performed as follows.

Activation/deactivation method based on minimum deactivation time

A "minimum deactivation time" may be set separately from the time indicated by the SCell deactivation time field included in the RRC message. The "minimum inactivity time" may be preset in the base station and the UE. Alternatively, the "minimum inactivity time" may be transmitted to the UE through an RRC message. The UE may obtain the SCell deactivation time field and "minimum deactivation time", and may compare the time indicated by the SCell deactivation time field with the "minimum deactivation time". If the time indicated by the SCell deactivation time field is greater than the "minimum deactivation time", the UE may activate a timer for the time indicated by the SCell deactivation time field, and deactivate the unlicensed band cell when the timer expires. can do. On the other hand, if the time indicated by the SCell deactivation time field is less than the "minimum deactivation time", the UE may activate a timer for the "minimum deactivation time" and deactivate the unlicensed band cell when the timer expires. there is. Here, "minimum inactivation time" may indicate an infinite amount of time. In this case, the UE may activate the timer for "minimum deactivation time" regardless of the SCell deactivation time field.

SCell Activation/deactivation method based on the time indicated by the deactivation time field

The UE may calculate the changed time by multiplying the time indicated by the SCell deactivation time field by a preset integer. The UE may activate a timer for the changed time, and may deactivate the unlicensed band cell when the timer expires. Here, the preset integer may be preset in the base station and the UE. Alternatively, the preset integer may be transmitted to the UE through an RRC message.

license-exempt defined for band cells license-exempt treason SCell Activation/deactivation method based on deactivation time field

The UE may acquire the unlicensed band SCell deactivation time field through RRC signaling in the licensed band or the unlicensed band. The unlicensed band SCell deactivation time field may be used for communication nodes operating in the unlicensed band. The UE may activate a timer for the time indicated by the unlicensed band SCell deactivation time field, and may deactivate the unlicensed band cell when the timer expires.

The time indicated by the unlicensed band SCell deactivation time field (eg, deactivation timer) may be configured for each SCell. That is, the deactivation timer for the SCell of the unlicensed band may be configured differently for each SCell. Also, the deactivation timer for the SCell of the unlicensed band may be different from the deactivation timer for the SCell of the licensed band.

indicating infinite time SCell Activation/deactivation method based on deactivation time field

If the SCell deactivation time field indicates an infinite amount of time, the UE may activate or deactivate the unlicensed band cell based on the activation/deactivation MAC CE.

Meanwhile, unlike activation/deactivation of a cell in a licensed band, activation/deactivation of a cell in an unlicensed band may be performed based on PDCCH (or EPDCCH) instead of MAC CE. A method of activating/deactivating an unlicensed band cell based on PDCCH (or EPDCCH) is as follows.

12 is a timing diagram illustrating a first embodiment of a method for activating an unlicensed band cell.

Referring to FIG. 12 , a base station and a UE may form the wireless communication network described with reference to FIGS. 1 to 4 and may support a licensed band and an unlicensed band. A base station may support carrier aggregation in a licensed band and an unlicensed band. The base station and UE may be configured identically or similarly to the communication node 500 described with reference to FIG. 5 . Subframe (or slot, OFDM symbol, etc.) timing of the licensed band may be the same as subframe (or slot, OFDM symbol, etc.) timing of the unlicensed band. A configuration of the unlicensed band burst may be the same as or similar to that of the unlicensed band burst described with reference to FIG. 9 . Unlicensed band bursts may be scheduled based on cross-carrier scheduling or self-scheduling.

The base station transmits a PDCCH (or EPDCCH) including information requesting activation of an unlicensed band cell (hereinafter referred to as "activation request information") to a subframe of a licensed band cell (or another unlicensed band cell in an activated state) # It can transmit at (n+1). The CRC of the PDCCH (or EPDCCH) including the activation request information may be masked (eg, scrambled) based on the C-RNTI. In addition, the PDCCH (or EPDCCH) may include scheduling information (eg, an uplink grant) for uplink resources of an unlicensed band cell, scheduling information for downlink resources of an unlicensed band cell, etc. .

The activation request information may be at least one of information indicating an unlicensed band cell in an inactive state (eg, CIF included in DCI) and activation/deactivation MAC CE requesting activation of an unlicensed band cell. Here, activation/deactivation MAC CE may consist of 1 bit. For example, an activation/deactivation MAC CE set to 0 may request activation of an unlicensed band cell, and an activation/deactivation MAC CE set to 1 may request deactivation of an unlicensed band cell. Conversely, an activation/deactivation MAC CE set to 0 may request deactivation of an unlicensed band cell, and an activation/deactivation MAC CE set to 1 may request activation of an unlicensed band cell.

The UE may receive PDCCH (or EPDCCH) in subframe #(n+1) of the licensed band cell. The UE may obtain activation request information included in the PDCCH (or EPDCCH) by performing descrambling based on the C-RNTI. That is, the UE may determine that activation of the unlicensed band cell is requested from subframe #(n+1+N _Act ) by checking the activation request information included in the PDCCH (or EPDCCH). For example, the UE may determine that activation of an unlicensed band cell indicated by a CIF included in DCI is requested. Alternatively, the UE may determine that activation of the unlicensed band cell is requested based on the activation/deactivation MAC CE.

N _Act may be an integer greater than or equal to 1. For example, N _Act can be 2, 4, 8, etc. N _Act can be preset in the base station and UE. Alternatively, N _Act may be transmitted to the UE through RRC signaling. Alternatively, DCI may include a new field indicating N _Act , and DCI may be transmitted to the UE through PDCCH (or EPDCCH). Alternatively, N _Act may be set based on UE capability (eg, reception/decoding capability), and in this case, N _Act is a reporting procedure for UE capability information (or RRC related to unlicensed band cells). It may be transmitted through a transmission procedure of a response to signaling).

Meanwhile, since the unlicensed band cell is activated from subframe #(n+1+N _Act ), the UE transmits the PDSCH included in subframe #(n+1) of the unlicensed band cell scheduled by PDCCH (or EPDCCH) cannot receive Therefore, the UE sends a HARQ response (eg, NACK, DTX) indicating reception failure of the PDSCH included in subframe #(n+1) of the unlicensed band cell to subframe #(n+5) of the licensed band cell. can be transmitted to the base station. Alternatively, the UE sends an HARQ response (eg, ACK) indicating successful reception of the PDCCH (or EPDCCH) included in subframe # (n + 1) of the licensed band cell to subframe # (n +5) to the base station.

If the HARQ response (eg, ACK, NACK, DTX) is received in subframe # (n + 5) of the licensed band cell, the base station may determine that the UE has activated the unlicensed band cell. In this case, the base station may perform scheduling for downlink resources (eg, PDSCH) of the unlicensed band cell from subframe #(n+5+m). Here, m may be set based on the capability of the base station (eg, decoding capability of the HARQ response). For example, m may be 2.

On the other hand, if the HARQ response is not received in subframe #(n+5) of the licensed band cell, the base station may determine that the UE failed to activate the unlicensed band cell. In this case, the base station may request the UE to activate the unlicensed band cell again based on the method of activating the unlicensed band cell described above. The base station may perform scheduling for downlink resources (or uplink resources) of the unlicensed band cell based on a preset operation policy before receiving the HARQ response.

The UE may activate the unlicensed band cell from subframe #(n+1+N _Act ). For example, when N _Act is 4, the UE may activate an unlicensed band cell from subframe #(n+5). That is, the activation timer may operate from subframe #(n+5) of the unlicensed band cell. The UE may receive the PDCCH (or EPDCCH) by monitoring the common search space or the UE-specific search space from subframe #(n+5) of the unlicensed band cell. For example, the UE may receive PDCCH (or EPDCCH) in subframe #(n+7) of the unlicensed band cell. The UE can obtain scheduling information from the PDCCH (or EPDCCH) by performing descrambling based on the C-RNTI. The UE may receive the PDSCH in subframe #(n+7) of the unlicensed band cell indicated by the scheduling information. The UE can obtain data from the PDSCH by performing descrambling based on the C-RNTI. In addition, the UE may transmit the PUSCH to the base station through uplink resources indicated by scheduling information.

Meanwhile, in order to deactivate an unlicensed band cell, the base station transmits a PDCCH (or EPDCCH) including information requesting deactivation of the unlicensed band cell (hereinafter referred to as "deactivation request information") to a licensed band cell (or unlicensed band cell). ) in subframe # (n + 11). The CRC of the PDCCH (or EPDCCH) including the deactivation request information may be masked (eg, scrambled) based on the C-RNTI. The deactivation request information may be at least one of information that does not indicate a specific meaning (eg, RB information all set to 0) among information included in the activation/deactivation MAC CE and DCI requesting deactivation of the unlicensed band cell. .

The UE may receive PDCCH (or EPDCCH) in subframe #(n+11) of the licensed band cell. The UE may obtain deactivation request information included in the PDCCH (or EPDCCH) by performing descrambling based on the C-RNTI. That is, the UE may determine that the deactivation of the unlicensed band cell is requested from subframe # (n + 11 + N _Dact ) by checking the deactivation request information included in the PDCCH (or EPDCCH).

N _Dact may be an integer greater than or equal to 1. For example, N _Dact may be 2, 4, 8, and the like. N _Dact may be preset in the base station and the UE. Alternatively, N _Dact may be transmitted to the UE through RRC signaling. Alternatively, DCI may include a new field indicating N _Dact , and DCI may be transmitted to the UE through PDCCH (or EPDCCH). Alternatively, N _Dact may be configured based on UE capability (eg, reception/decoding capability), in which case N _Dact may be a reporting procedure for capability information of the UE (or unlicensed band cell-related It may be transmitted through a transmission procedure of a response to RRC signaling).

The UE may deactivate the unlicensed band cell from subframe #(n+11+N _Dact ). For example, if N _Dact is 2, the UE may deactivate the unlicensed band cell from subframe #(n+13). That is, the UE may not perform monitoring for the common search space or the UE-specific search space from subframe #(n+13) of the unlicensed band cell.

13 is a timing diagram illustrating a second embodiment of a method for activating an unlicensed band cell.

Referring to FIG. 13 , a base station, UE1 and UE2 may form the wireless communication network described with reference to FIGS. 1 to 4 and may support a licensed band and an unlicensed band. A base station may support carrier aggregation in a licensed band and an unlicensed band. The base station, UE1 and UE2 may be configured identically or similarly to the communication node 500 described with reference to FIG. 5 . Subframe (or slot, OFDM symbol, etc.) timing of the licensed band may be the same as subframe (or slot, OFDM symbol, etc.) timing of the unlicensed band. A configuration of the unlicensed band burst may be the same as or similar to that of the unlicensed band burst described with reference to FIG. 9 . Unlicensed band bursts may be scheduled based on cross-carrier scheduling or self-scheduling.

The base station may transmit a PDCCH (or EPDCCH) including activation request information of an unlicensed band cell in subframe #(n+1) of a licensed band cell (or another unlicensed band cell in an activated state). The PDCCH (or EPDCCH) may be transmitted in a common search space or a CCE (or ECCE) in a UE-specific search space indicated by "unlicensed band cell common U-RNTI". The CRC of the PDCCH (or EPDCCH) including the activation request information may be masked (eg, scrambled) based on the "unlicensed band cell common U-RNTI". In addition, the PDCCH (or EPDCCH) may include scheduling information (eg, uplink grant) for uplink resources of an unlicensed band cell, scheduling information for downlink resources of an unlicensed band cell, and the like. The activation request information may be at least one of information indicating an unlicensed band cell in an inactive state (eg, CIF included in DCI) and activation/deactivation MAC CE requesting activation of an unlicensed band cell. The activation/deactivation MAC CE may be the same as the activation/deactivation MAC CE described with reference to FIG. 12 .

UE1 and UE2 may receive PDCCH (or EPDCCH) in subframe #(n+1) of the licensed band cell. UE1 and UE2 may obtain activation request information included in PDCCH (or EPDCCH) by performing descrambling based on "unlicensed band cell common U-RNTI". That is, UE1 and UE2 may determine that activation of the unlicensed band cell is requested by checking the activation request information included in the PDCCH (or EPDCCH). For example, UE1 and UE2 may determine that activation of an unlicensed band cell indicated by a CIF included in DCI is requested. Alternatively, UE1 and UE2 may determine that activation of the unlicensed band cell is requested based on the activation/deactivation MAC CE. UE1 and UE2 may activate an unlicensed band cell according to PDCCH (or EPDCCH) decoding capability. For example, UE1 may activate an unlicensed band cell from subframe #(n+4). UE2 may activate an unlicensed band cell from subframe #(n+5).

Meanwhile, UE1 and UE2 cannot receive the PDSCH included in subframe #(n+1) of an unlicensed band cell scheduled by the PDCCH (or EPDCCH). Therefore, UE1 and UE2 transmit HARQ responses (eg, NACK, DTX) indicating reception failure of the PDSCH included in subframe #(n+1) of the unlicensed band cell to subframe #(n+1) of the unlicensed band cell. In 5), it can be transmitted to the base station. Alternatively, UE1 and UE2 transmit an HARQ response (eg, ACK) indicating successful reception of the PDCCH (or EPDCCH) included in subframe #(n+1) of the licensed band cell to subframe # of the licensed band cell. It can be transmitted to the base station at (n + 5). If the HARQ response (eg, ACK, NACK, DTX) is received in subframe # (n + 5) of the licensed band cell, the base station may determine that UE1 and UE2 have activated the unlicensed band cell.

On the other hand, if the HARQ response is not received in subframe #(n+5) of the licensed band cell, the base station may determine that UE1 and UE2 failed to activate the unlicensed band cell. In this case, the base station may request the UE to activate the unlicensed band cell again based on the method of activating the unlicensed band cell described above. The base station may perform scheduling for downlink resources (or uplink resources) of the unlicensed band cell based on a preset operation policy before receiving the HARQ response. Here, when a PDCCH (or EPDCCH) including activation request information is transmitted in a common search space, UE1 and UE2 may not transmit an HARQ response to the base station.

The base station may perform downlink transmission from subframe #(n+1+N _Act ) of the unlicensed band cell. N _Act may be the same as N _Act described with reference to FIG. 12 . When N _Act is 4, the base station may transmit a PDCCH (or EPDCCH) and a PDSCH scheduled by the PDCCH (or EPDCCH) in subframe #(n+5) of the unlicensed band cell. Here, the CRC of the PDCCH (or EPDCCH) may be masked (eg, scrambled) based on the C-RNTI (or unlicensed band cell common U-RNTI). UE1 and UE2 may receive a PDCCH (or EPDCCH) by monitoring a common search space or a UE-specific search space in subframe #(n+5) of an unlicensed band cell. UE1 and UE2 may obtain scheduling information from PDCCH (or EPDCCH) by performing descrambling based on C-RNTI (or unlicensed band cell common U-RNTI). UE1 and UE2 may receive the PDSCH in subframe #(n+5) of the unlicensed band cell indicated by the scheduling information. UE1 and UE2 may obtain data from the PDSCH by performing descrambling based on the C-RNTI (or the unlicensed band cell common U-RNTI). In addition, UE1 and UE2 may transmit the PUSCH to the base station through uplink resources indicated by scheduling information.

In addition, when the PDSCH is received in subframe #(n+5) of the unlicensed band cell, UE1 and UE2 transmit a HARQ response (eg, ACK) indicating successful reception of the PDSCH to subframe # ( n + 9) can be transmitted to the base station. Alternatively, when the PDSCH is not received in subframe #(n+5) of the unlicensed band cell, UE1 and UE2 transmit an HARQ response (eg, NACK, DTX) indicating PDSCH reception failure to the subframe of the unlicensed band cell. It can be transmitted to the base station in frame # (n + 9). If the HARQ response (eg, ACK, NACK, DTX) is received in subframe #(n+9) of the licensed band cell, the base station may determine that UE1 and UE2 have activated the unlicensed band cell.

On the other hand, if the HARQ response (eg, ACK, NACK, DTX) is not received in subframe # (n + 9) of the licensed band cell, the base station determines that UE1 and UE2 failed to activate the unlicensed band cell. can In this case, the base station may request UE1 and UE2 to activate the unlicensed band cell again based on the method of activating the unlicensed band cell described above.

Meanwhile, for deactivation of an unlicensed band cell, a base station may transmit a PDCCH (or EPDCCH) including deactivation request information through subframe # (n + 11) of a licensed band cell (or unlicensed band cell). The CRC of the PDCCH (or EPDCCH) including the deactivation request information may be masked (eg, scrambled) based on the "unlicensed band cell common U-RNTI". The deactivation request information may be at least one of information that does not indicate a specific meaning (eg, RB information all set to 0) among information included in the activation/deactivation MAC CE and DCI requesting deactivation of the unlicensed band cell. .

UE1 and UE2 may receive PDCCH (or EPDCCH) in subframe #(n+11) of the licensed band cell. UE1 and UE2 may obtain deactivation request information included in PDCCH (or EPDCCH) by performing descrambling based on "unlicensed band cell common U-RNTI". That is, UE1 and UE2 may determine that deactivation of the unlicensed band cell is requested from subframe # (n+11+N _Dact ) by checking the deactivation request information included in the PDCCH (or EPDCCH). N _Dact may be the same as N _Dact described with reference to FIG. 12 .

UE1 and UE2 may deactivate the unlicensed band cell from subframe #(n+11+N _Dact ). For example, when N _Dact is 2, UE1 and UE2 may deactivate the unlicensed band cell from subframe #(n+13). That is, UE1 and UE2 may not perform monitoring for a common search space or a UE-specific search space from subframe #(n+13) of the unlicensed band cell.

14 is a timing diagram illustrating a third embodiment of a method for activating an unlicensed band cell.

Referring to FIG. 14 , a base station, UE1 and UE2 may form the wireless communication network described with reference to FIGS. 1 to 4 and may support a licensed band and an unlicensed band. A base station may support carrier aggregation in a licensed band and an unlicensed band. The base station, UE1 and UE2 may be configured identically or similarly to the communication node 500 described with reference to FIG. 5 . Subframe (or slot, OFDM symbol, etc.) timing of the licensed band may be the same as subframe (or slot, OFDM symbol, etc.) timing of the unlicensed band. A configuration of the unlicensed band burst may be the same as or similar to that of the unlicensed band burst described with reference to FIG. 9 . Unlicensed band bursts may be scheduled based on cross-carrier scheduling or self-scheduling.

The base station may transmit a PDCCH (or EPDCCH) including activation request information of an unlicensed band cell in subframe #(n+1) of a licensed band cell (or another unlicensed band cell in an activated state). The PDCCH (or EPDCCH) may be transmitted in a common search space or a CCE (or ECCE) in a UE-specific search space indicated by "unlicensed band cell common U-RNTI". The CRC of the PDCCH (or EPDCCH) including the activation request information may be masked (eg, scrambled) based on the "unlicensed band cell common U-RNTI". In addition, the PDCCH (or EPDCCH) may include scheduling information (eg, uplink grant) for uplink resources of an unlicensed band cell, scheduling information for downlink resources of an unlicensed band cell, and the like.

The activation request information may be at least one of information indicating an unlicensed band cell in an inactive state (eg, CIF included in DCI) and activation/deactivation MAC CE requesting activation of an unlicensed band cell. The activation/deactivation MAC CE may be the same as the activation/deactivation MAC CE described with reference to FIG. 12 .

In addition, since there may be a UE that does not receive the PDCCH (or EPDCCH) transmitted in subframe #(n+1) of a licensed band cell (or another unlicensed band cell in an active state), the base station A PDCCH (or EPDCCH) including activation request information may be retransmitted in subframe #(n+3) of a licensed band cell (or another unlicensed band cell in an activated state). Here, PDCCH (or EPDCCH) may be retransmitted before subframe #(n+1+N _Act ). The PDCCH (or EPDCCH) retransmitted in subframe #(n+3) may be the same as the PDCCH (or EPDCCH) transmitted in subframe #(n+1).

After the PDCCH (or EPDCCH) including the activation request information of the unlicensed band cell is transmitted, the operations of the base station, UE1, and UE2 may be the same as those of the base station, UE1, and UE2 described with reference to FIG. 13. That is, when the retransmission operation of the PDCCH (or EPDCCH) including the activation request information of the unlicensed band cell is omitted in subframe #(n+3) of the licensed band cell, the timing diagram shown in FIG. 14 is shown in FIG. It may be the same as the timing diagram shown.

15 is a timing diagram illustrating a fourth embodiment of a method for activating an unlicensed band cell.

Referring to FIG. 15 , a base station, UE1 and UE2 may form the wireless communication network described with reference to FIGS. 1 to 4 and may support a licensed band and an unlicensed band. A base station may support carrier aggregation in a licensed band and an unlicensed band. The base station, UE1 and UE2 may be configured identically or similarly to the communication node 500 described with reference to FIG. 5 . Subframe (or slot, OFDM symbol, etc.) timing of the licensed band may be the same as subframe (or slot, OFDM symbol, etc.) timing of the unlicensed band. A configuration of the unlicensed band burst may be the same as or similar to that of the unlicensed band burst described with reference to FIG. 9 . Unlicensed band bursts may be scheduled based on cross-carrier scheduling or self-scheduling.

The base station may transmit a PDCCH (or EPDCCH) including activation request information of an unlicensed band cell in subframe #(n+1) of a licensed band cell (or another unlicensed band cell in an activated state). The PDCCH (or EPDCCH) may be transmitted in a common search space or a CCE (or ECCE) in a UE-specific search space indicated by "unlicensed band cell common U-RNTI". The CRC of the PDCCH (or EPDCCH) including the activation request information may be masked (eg, scrambled) based on the "unlicensed band cell common U-RNTI". In addition, the PDCCH (or EPDCCH) may include scheduling information (eg, uplink grant) for uplink resources of an unlicensed band cell, scheduling information for downlink resources of an unlicensed band cell, and the like.

The activation request information may be at least one of information indicating an unlicensed band cell in an inactive state (eg, CIF included in DCI) and activation/deactivation MAC CE requesting activation of an unlicensed band cell. The activation/deactivation MAC CE may be the same as the activation/deactivation MAC CE described with reference to FIG. 12 .

UE1 may receive PDCCH (or EPDCCH) in subframe #(n+1) of the licensed band cell. UE1 may obtain activation request information included in PDCCH (or EPDCCH) by performing descrambling based on "unlicensed band cell common U-RNTI". That is, UE1 may determine that activation of the unlicensed band cell is requested by checking the activation request information included in the PDCCH (or EPDCCH). For example, UE1 may determine that activation of an unlicensed band cell indicated by a CIF included in DCI is requested. Alternatively, UE1 may determine that activation of the unlicensed band cell is requested based on the activation/deactivation MAC CE. Accordingly, UE1 may activate the unlicensed band cell from subframe #(n+4).

On the other hand, UE2 may not be able to receive PDCCH (or EPDCCH) in subframe #(n+1) of the licensed band cell. In this case, UE2 may not be able to confirm that activation of the unlicensed band cell is requested. Therefore, UE2 may not be able to activate the unlicensed band cell.

Meanwhile, the base station may perform downlink transmission from subframe #(n+1+N _Act ) of the unlicensed band cell. N _Act may be the same as N _Act described with reference to FIG. 12 . When N _Act is 4, the base station may transmit a PDCCH (or EPDCCH) and a PDSCH scheduled by the PDCCH (or EPDCCH) in subframe #(n+5) of the unlicensed band cell. Here, the CRC of the PDCCH (or EPDCCH) may be masked (eg, scrambled) based on the C-RNTI (or unlicensed band cell common U-RNTI). UE1 may receive the PDCCH (or EPDCCH) by monitoring the common search space or the UE-specific search space in subframe #(n+5) of the unlicensed band cell. UE1 may obtain scheduling information from PDCCH (or EPDCCH) by performing descrambling based on C-RNTI (or unlicensed band cell common U-RNTI). UE1 may receive the PDSCH in subframe #(n+5) of the unlicensed band cell indicated by the scheduling information. UE1 may obtain data from the PDSCH by performing descrambling based on the C-RNTI (or unlicensed band cell common U-RNTI). In addition, UE1 may transmit the PUSCH to the base station through uplink resources indicated by scheduling information.

Meanwhile, when the PDSCH is received in subframe #(n+5) of the unlicensed band cell, UE1 sends a HARQ response (eg, ACK) indicating successful reception of the PDSCH to subframe #(n+5) of the licensed band cell. 9) can transmit to the base station. Alternatively, if the PDSCH is not received in subframe #(n+5) of the unlicensed band cell, UE1 transmits a HARQ response (eg, NACK, DTX) indicating PDSCH reception failure in subframe # of the unlicensed band cell. It can be transmitted to the base station at (n + 9). If the HARQ response (eg, ACK, NACK, DTX) is received in subframe #(n+9) of the licensed band cell, the base station may determine that UE1 has activated the unlicensed band cell.

On the other hand, since the state of the unlicensed band cell is inactive, UE2 cannot receive PDCCH (or EPDCCH) and PDSCH in subframe #(n+5) of the unlicensed band cell. Therefore, UE2 cannot transmit HARQ responses (eg, ACK, NACK, DTX) for PDSCH to the base station in subframe #(n+9) of the licensed band cell. Since the HARQ response is not received in subframe #(n+9) of the licensed band cell, the base station may determine that UE2 failed to activate the unlicensed band cell. Accordingly, the base station may request UE2 to activate the unlicensed band cell again based on the above-described activation method of the unlicensed band cell.

16 is a timing diagram illustrating a fifth embodiment of a method for activating an unlicensed band cell.

Referring to FIG. 16 , a base station and a UE may form the wireless communication network described with reference to FIGS. 1 to 4 and may support a licensed band and an unlicensed band. A base station may support carrier aggregation in a licensed band and an unlicensed band. The base station and UE may be configured identically or similarly to the communication node 500 described with reference to FIG. 5 . Subframe (or slot, OFDM symbol, etc.) timing of the licensed band may be the same as subframe (or slot, OFDM symbol, etc.) timing of the unlicensed band. A configuration of the unlicensed band burst may be the same as or similar to that of the unlicensed band burst described with reference to FIG. 9 . Unlicensed band bursts may be scheduled based on cross-carrier scheduling or self-scheduling.

The base station may transmit a PDCCH (or EPDCCH) including activation request information of an unlicensed band cell in subframe #(n+1) of a licensed band cell (or another unlicensed band cell in an activated state). The CRC of the PDCCH (or EPDCCH) including activation request information may be masked (eg, scrambled) based on “UE-specific U-RNTI (or activation U-RNTI)”. In addition, the PDCCH (or EPDCCH) may include scheduling information (eg, uplink grant) for uplink resources of an unlicensed band cell, scheduling information for downlink resources of an unlicensed band cell, and the like.

The activation request information may be at least one of information indicating an unlicensed band cell in an inactive state (eg, CIF included in DCI) and activation/deactivation MAC CE requesting activation of an unlicensed band cell. The activation/deactivation MAC CE may be the same as the activation/deactivation MAC CE described with reference to FIG. 12 .

The UE may receive PDCCH (or EPDCCH) in subframe #(n+1) of the licensed band cell. The UE may obtain activation request information included in PDCCH (or EPDCCH) by performing descrambling based on "UE-specific U-RNTI (or activation U-RNTI)". That is, the UE may determine that activation of the unlicensed band cell is requested from subframe #(n+1+N _Act ) by checking the activation request information included in the PDCCH (or EPDCCH). N _Act may be the same as N _Act described with reference to FIG. 12 . For example, the UE may determine that activation of an unlicensed band cell indicated by a CIF included in DCI is requested. Alternatively, the UE may determine that activation of the unlicensed band cell is requested based on the activation/deactivation MAC CE.

Meanwhile, since the unlicensed band cell is activated from subframe #(n+1+N _Act ), the UE transmits the PDSCH included in subframe #(n+1) of the unlicensed band cell scheduled by PDCCH (or EPDCCH) cannot receive Therefore, the UE sends a HARQ response (eg, NACK, DTX) indicating reception failure of the PDSCH included in subframe #(n+1) of the unlicensed band cell to subframe #(n+5) of the licensed band cell. can be transmitted to the base station. Alternatively, the UE sends an HARQ response (eg, ACK) indicating successful reception of the PDCCH (or EPDCCH) included in subframe # (n + 1) of the licensed band cell to subframe # (n +5) to the base station.

If the HARQ response (eg, ACK, NACK, DTX) is received in subframe # (n + 5) of the licensed band cell, the base station may determine that the UE has activated the unlicensed band cell. In this case, the base station may perform scheduling for downlink resources (eg, PDSCH) of the unlicensed band cell from subframe #(n+5+m). Here, m may be set based on the capability of the base station (eg, decoding capability of the HARQ response). For example, m may be 2.

On the other hand, if the HARQ response (eg, ACK, NACK, DTX) is not received in subframe # (n + 5) of the licensed band cell, the base station may determine that the UE failed to activate the unlicensed band cell . In this case, the base station may request the UE to activate the unlicensed band cell again based on the method of activating the unlicensed band cell described above. The base station may perform scheduling for downlink resources (or uplink resources) of the unlicensed band cell based on a preset operation policy before receiving the HARQ response.

The UE may activate the unlicensed band cell from subframe #(n+1+N _Act ). For example, when N _Act is 4, the UE may activate an unlicensed band cell from subframe #(n+5). That is, the activation timer may operate from subframe #(n+5) of the unlicensed band cell. The UE may receive the PDCCH (or EPDCCH) by monitoring the common search space or the UE-specific search space from subframe #(n+5) of the unlicensed band cell. For example, the UE may receive PDCCH (or EPDCCH) in subframe #(n+7) of the unlicensed band cell. The UE may obtain scheduling information from the PDCCH (or EPDCCH) by performing descrambling based on "UE-specific U-RNTI (or activation U-RNTI)". The UE may receive the PDSCH in subframe #(n+7) of the unlicensed band cell indicated by the scheduling information. The UE may acquire data from the PDSCH by performing descrambling based on "UE-specific U-RNTI (or activation U-RNTI)". In addition, the UE may transmit the PUSCH to the base station through uplink resources indicated by scheduling information.

Meanwhile, for deactivation of an unlicensed band cell, a base station may transmit a PDCCH (or EPDCCH) including deactivation request information in subframe # (n + 11) of a licensed band cell (or unlicensed band cell). The CRC of the PDCCH (or EPDCCH) including the deactivation request information may be masked (eg, scrambled) based on “UE-specific U-RNTI (or deactivation U-RNTI)”. The deactivation request information may be at least one of information that does not indicate a specific meaning (eg, RB information all set to 0) among information included in the activation/deactivation MAC CE and DCI requesting deactivation of the unlicensed band cell. .

The UE may receive PDCCH (or EPDCCH) in subframe #(n+11) of the licensed band cell. The UE may obtain deactivation request information included in PDCCH (or EPDCCH) by performing descrambling based on "UE-specific U-RNTI (or deactivation U-RNTI)". That is, the UE may determine that the deactivation of the unlicensed band cell is requested from subframe # (n + 11 + N _Dact ) by checking the deactivation request information included in the PDCCH (or EPDCCH). N _Dact may be the same as N _Dact described with reference to FIG. 12 .

The UE may deactivate the unlicensed band cell from subframe #(n+11+N _Dact ). For example, if N _Dact is 2, the UE may deactivate the unlicensed band cell from subframe #(n+13). That is, the UE may not perform monitoring for the common search space or the UE-specific search space from subframe #(n+13) of the unlicensed band cell.

17 is a timing diagram illustrating a sixth embodiment of a method for activating an unlicensed band cell.

Referring to FIG. 17 , a base station and a UE may form the wireless communication network described with reference to FIGS. 1 to 4 and may support a licensed band and an unlicensed band. A base station may support carrier aggregation in a licensed band and an unlicensed band. The base station and UE may be configured identically or similarly to the communication node 500 described with reference to FIG. 5 . Subframe (or slot, OFDM symbol, etc.) timing of the licensed band may be the same as subframe (or slot, OFDM symbol, etc.) timing of the unlicensed band. A configuration of the unlicensed band burst may be the same as or similar to that of the unlicensed band burst described with reference to FIG. 9 . Unlicensed band bursts may be scheduled based on cross-carrier scheduling or self-scheduling.

The base station may transmit a PDCCH (or EPDCCH) including activation request information of an unlicensed band cell in subframe #(n+1) of a licensed band cell (or another unlicensed band cell in an activated state). The CRC of the PDCCH (or EPDCCH) including activation request information may be masked (eg, scrambled) based on “UE-specific U-RNTI (or activation U-RNTI)”. In addition, the PDCCH (or EPDCCH) may include scheduling information (eg, uplink grant) for uplink resources of an unlicensed band cell, scheduling information for downlink resources of an unlicensed band cell, and the like.

The activation request information may be at least one of information indicating an unlicensed band cell in an inactive state (eg, CIF included in DCI) and activation/deactivation MAC CE requesting activation of an unlicensed band cell. The activation/deactivation MAC CE may be the same as the activation/deactivation MAC CE described with reference to FIG. 12 .

The UE may not be able to receive the PDCCH (or EPDCCH) in subframe #(n+1) of the licensed band cell. In this case, the UE may not be able to transmit the HARQ response to the PDCCH (or EPDCCH) or the HARQ response to the PDSCH scheduled by the PDCCH (or EPDCCH) to the base station. If the HARQ response for subframe #(n+1) of the licensed band cell is not received in subframe #(n+5) of the licensed band cell, the base station may determine that the UE failed to activate the unlicensed band cell. there is. In this case, the base station may retransmit the PDCCH (or EPDCCH) including the activation request information of the unlicensed band cell in subframe # (n + 7) of the licensed band cell (or another unlicensed band cell in an activated state). . The CRC of the PDCCH (or EPDCCH) including activation request information may be masked (eg, scrambled) based on “UE-specific U-RNTI (or activation U-RNTI)”. Here, the PDCCH (or EPDCCH) retransmitted in subframe #(n+7) may be the same as the PDCCH (or EPDCCH) transmitted in subframe #(n+1).

The UE may receive PDCCH (or EPDCCH) in subframe #(n+7) of the licensed band cell. The UE may obtain activation request information included in PDCCH (or EPDCCH) by performing descrambling based on "UE-specific U-RNTI (or activation U-RNTI)". That is, the UE may determine that activation of the unlicensed band cell is requested from subframe #(n+7+N _Act ) by checking the activation request information included in the PDCCH (or EPDCCH). N _Act may be the same as N _Act described with reference to FIG. 12 . For example, the UE may determine that activation of an unlicensed band cell indicated by a CIF included in DCI is requested. Alternatively, the UE may determine that activation of the unlicensed band cell is requested based on the activation/deactivation MAC CE.

Meanwhile, since the unlicensed band cell is activated from subframe #(n+7+N _Act ), the UE transmits the PDSCH included in subframe #(n+7) of the unlicensed band cell scheduled by PDCCH (or EPDCCH) cannot receive Therefore, the UE sends a HARQ response (eg, NACK, DTX) indicating reception failure of the PDSCH included in subframe #(n+7) of the unlicensed band cell to subframe #(n+11) of the licensed band cell. can be transmitted to the base station. Alternatively, the UE sends an HARQ response (eg, ACK) indicating successful reception of the PDCCH (or EPDCCH) included in subframe # (n + 7) of the licensed band cell to subframe # (n + 7) of the licensed band cell +11) to the base station.

If the HARQ response (eg, ACK, NACK, DTX) is received in subframe # (n + 11) of the licensed band cell, the base station may determine that the UE has activated the unlicensed band cell. In this case, the base station may perform scheduling for downlink resources (eg, PDSCH) of the unlicensed band cell from subframe #(n+11+m). Here, m may be set based on the capability of the base station (eg, decoding capability of the HARQ response). For example, m may be 2.

The UE may activate the unlicensed band cell from subframe #(n+7+N _Act ). For example, when N _Act is 4, the UE may activate an unlicensed band cell from subframe #(n+11). That is, the activation timer may operate from subframe #(n+11) of the unlicensed band cell. The UE may receive the PDCCH (or EPDCCH) by monitoring the common search space or the UE-specific search space from subframe #(n+11) of the unlicensed band cell. For example, the UE may receive PDCCH (or EPDCCH) in subframe #(n+13) of the unlicensed band cell. The UE may obtain scheduling information from the PDCCH (or EPDCCH) by performing descrambling based on "UE-specific U-RNTI (or active U-RNTI)". The UE may receive the PDSCH in subframe #(n+13) of the unlicensed band cell indicated by the scheduling information. The UE can acquire data from the PDSCH by performing descrambling based on "UE-specific U-RNTI (or activation U-RNTI)". In addition, the UE may transmit the PUSCH to the base station through uplink resources indicated by scheduling information.

18 is a timing diagram illustrating a seventh embodiment of a method for activating an unlicensed band cell.

Referring to FIG. 18 , a base station and a UE may form the wireless communication network described with reference to FIGS. 1 to 4 and may support a licensed band and an unlicensed band. A base station may support carrier aggregation in a licensed band and an unlicensed band. The base station and UE may be configured identically or similarly to the communication node 500 described with reference to FIG. 5 . Subframe (or slot, OFDM symbol, etc.) timing of the licensed band may be the same as subframe (or slot, OFDM symbol, etc.) timing of the unlicensed band. A configuration of the unlicensed band burst may be the same as or similar to that of the unlicensed band burst described with reference to FIG. 9 . Unlicensed band bursts may be scheduled based on cross-carrier scheduling or self-scheduling.

The base station may transmit a PDCCH (or EPDCCH) including activation request information of an unlicensed band cell in subframe #(n+1) of a licensed band cell (or another unlicensed band cell in an activated state). The PDCCH (or EPDCCH) may be transmitted in a common search space or a CCE (or ECCE) in a UE-specific search space indicated by “UE-specific U-RNTI (or activation U-RNTI)”. The CRC of the PDCCH (or EPDCCH) including activation request information may be masked (eg, scrambled) based on “UE-specific U-RNTI (or activation U-RNTI)”. In addition, the PDCCH (or EPDCCH) may include scheduling information (eg, uplink grant) for uplink resources of an unlicensed band cell, scheduling information for downlink resources of an unlicensed band cell, and the like.

The activation request information may be at least one of information indicating an unlicensed band cell in an inactive state (eg, CIF included in DCI) and activation/deactivation MAC CE requesting activation of an unlicensed band cell. The activation/deactivation MAC CE may be the same as the activation/deactivation MAC CE described with reference to FIG. 12 .

In addition, since there may be a UE that does not receive the PDCCH (or EPDCCH) transmitted in subframe #(n+1) of a licensed band cell (or another unlicensed band cell in an active state), the base station A PDCCH (or EPDCCH) including activation request information may be retransmitted in subframe #(n+3) of a licensed band cell (or another unlicensed band cell in an activated state). Here, PDCCH (or EPDCCH) may be retransmitted before subframe #(n+1+N _Act ). The PDCCH (or EPDCCH) retransmitted in subframe #(n+3) may be the same as the PDCCH (or EPDCCH) transmitted in subframe #(n+1).

The UE may not be able to receive the PDCCH (or EPDCCH) in subframe #(n+1) of the licensed band cell. In this case, the UE may not be able to transmit the HARQ response to the PDCCH (or EPDCCH) or the HARQ response to the PDSCH scheduled by the PDCCH (or EPDCCH) to the base station. If the HARQ response for subframe #(n+1) of the licensed band cell is not received in subframe #(n+5) of the licensed band cell, the base station may determine that the UE failed to activate the unlicensed band cell. there is.

Meanwhile, the UE may receive PDCCH (or EPDCCH) in subframe #(n+3) of the licensed band cell. The UE may obtain activation request information included in PDCCH (or EPDCCH) by performing descrambling based on "UE-specific U-RNTI (or activation U-RNTI)". That is, the UE may determine that activation of the unlicensed band cell is requested by checking the activation request information included in the PDCCH (or EPDCCH). For example, the UE may determine that activation of an unlicensed band cell indicated by a CIF included in DCI is requested. Alternatively, the UE may determine that activation of the unlicensed band cell is requested based on the activation/deactivation MAC CE.

In addition, the UE transmits an HARQ response (eg, ACK) indicating successful reception of the PDCCH (or EPDCCH) included in subframe # (n + 3) of the licensed band cell to subframe # (n + 3) of the licensed band cell. +7) to the base station. If the HARQ response is received in subframe #(n+7) of the licensed band cell, the base station may determine that the UE has activated the unlicensed band cell.

The UE may activate the unlicensed band cell from subframe #(n+6). That is, the activation timer may be operated from subframe #(n+6) of the unlicensed band cell. Meanwhile, the base station may transmit a PDCCH (or EPDCCH) and a PDSCH scheduled by the PDCCH (or EPDCCH) in subframe #(n+11) of the unlicensed band cell. Since the state of the unlicensed band cell is active, the UE can receive PDCCH (or EPDCCH) in subframe # (n + 11) of the unlicensed band cell, and obtain scheduling information from the received PDCCH (or EPDCCH) can do. The UE may receive the PDSCH in subframe #(n+11) of the unlicensed band cell indicated by the scheduling information.

19 is a timing diagram illustrating an eighth embodiment of a method for activating an unlicensed band cell.

Referring to FIG. 19 , a base station and a UE may form the wireless communication network described with reference to FIGS. 1 to 4 and support a licensed band and an unlicensed band. A base station may support carrier aggregation in a licensed band and an unlicensed band. The base station and UE may be configured identically or similarly to the communication node 500 described with reference to FIG. 5 . Subframe (or slot, OFDM symbol, etc.) timing of the licensed band may be the same as subframe (or slot, OFDM symbol, etc.) timing of the unlicensed band. A configuration of the unlicensed band burst may be the same as or similar to that of the unlicensed band burst described with reference to FIG. 9 . Unlicensed band bursts may be scheduled based on cross-carrier scheduling or self-scheduling.

The base station may transmit a PDCCH (or EPDCCH) including activation request information of an unlicensed band cell in subframe #(n+1) of a licensed band cell (or another unlicensed band cell in an activated state). The PDCCH (or EPDCCH) may be transmitted in a CCE (or ECCE) in a common search space or a UE-specific search space. The CRC of the PDCCH (or EPDCCH) including the activation request information may be masked (eg, scrambled) based on “UE-specific U-RNTI (or activation U-RNTI, C-RNTI)”. The activation request information may be at least one of information indicating an unlicensed band cell in an inactive state (eg, CIF included in DCI) and activation/deactivation MAC CE requesting activation of an unlicensed band cell. The activation/deactivation MAC CE may be the same as the activation/deactivation MAC CE described with reference to FIG. 12 . The PDCCH (or EPDCCH) may further include scheduling information (eg, an uplink grant) for uplink resources of an unlicensed band cell, scheduling information for downlink resources of an unlicensed band cell, and the like.

The UE may receive PDCCH (or EPDCCH) in subframe #(n+1) of the licensed band cell. The UE may obtain activation request information included in PDCCH (or EPDCCH) by performing descrambling based on "UE-specific U-RNTI (or activation U-RNTI, C-RNTI)". That is, the UE may determine that activation of the unlicensed band cell is requested by checking the activation request information included in the PDCCH (or EPDCCH). For example, the UE may determine that activation of an unlicensed band cell indicated by a CIF included in DCI is requested. Alternatively, the UE may determine that activation of the unlicensed band cell is requested based on the activation/deactivation MAC CE.

Descrambling for PDCCH (or EPDCCH) may be completed within a time corresponding to one subframe. In this case, the UE may activate the unlicensed band cell from the next subframe (ie, subframe #(n+2)). That is, the activation timer may be operated from subframe #(n+2) of the unlicensed band cell.

Meanwhile, the base station may transmit a PDCCH (or EPDCCH) and a PDSCH scheduled by the PDCCH (or EPDCCH) in subframe #(n+2) of the unlicensed band cell. Since the state of the unlicensed band cell is active, the UE can receive PDCCH (or EPDCCH) in subframe # (n + 2) of the unlicensed band cell, and obtain scheduling information from the received PDCCH (or EPDCCH) can do. The UE may receive the PDSCH in subframe #(n+2) of the unlicensed band cell indicated by the scheduling information.

When the PDSCH is received in subframe #(n+2) of the unlicensed band cell, the UE may transmit a HARQ response indicating successful reception of the PDSCH to the base station in subframe #(n+6) of the licensed band cell. When the HARQ response is received in subframe #(n+6) of the licensed band cell, the base station may determine that the UE has activated the unlicensed band cell.

Meanwhile, time corresponding to a plurality of subframes may be required to receive an HARQ response for a PDCCH (or EPDCCH) including activation request information of an unlicensed band cell. To solve this problem, a semi-static scheduling (SSS) based PUCCH may be configured, and an HARQ response to a PDCCH (or EPDCCH) including activation request information of an unlicensed band cell is transmitted on the SSS based PUCCH. It can be. Next, a method of activating an unlicensed band cell using SSS-based PUCCH will be described.

20 is a timing diagram illustrating a ninth embodiment of a method for activating an unlicensed band cell.

Referring to FIG. 20 , a base station and a UE may form the wireless communication network described with reference to FIGS. 1 to 4 and support a licensed band and an unlicensed band. A base station may support carrier aggregation in a licensed band and an unlicensed band. The base station and UE may be configured identically or similarly to the communication node 500 described with reference to FIG. 5 . Subframe (or slot, OFDM symbol, etc.) timing of the licensed band may be the same as subframe (or slot, OFDM symbol, etc.) timing of the unlicensed band. A configuration of the unlicensed band burst may be the same as or similar to that of the unlicensed band burst described with reference to FIG. 9 . Unlicensed band bursts may be scheduled based on cross-carrier scheduling or self-scheduling.

The base station may transmit an RRC message including SSS-based PUCCH-related information to the UE. SSS-based PUCCH-related information includes subframe information in which PUCCH is configured, resource information in which PUCCH is configured (eg, frequency resource location, time resource location), and PDCCH (or EPDCCH) reception response including activation request information. It may include information (eg, bit value, sequence, HARQ response, etc.) transmitted as . Subframe information in which PUCCH is configured may indicate the number of subframes (N _REP ) between a subframe in which PDCCH (or EPDCCH) including activation request information is configured and a subframe in which PUCCH is configured. N _REP may be an integer greater than or equal to 1. The UE may acquire SSS-based PUCCH-related information by receiving an RRC message from the base station.

Meanwhile, the base station may transmit a PDCCH (or EPDCCH) including activation request information of an unlicensed band cell in subframe # (n + 1) of a licensed band cell (or another unlicensed band cell in an activated state). The PDCCH (or EPDCCH) may be transmitted in a CCE (or ECCE) in a common search space or a UE-specific search space. The CRC of the PDCCH (or EPDCCH) including the activation request information may be masked (eg, scrambled) based on “UE-specific U-RNTI (or activation U-RNTI, C-RNTI)”. The activation request information may be at least one of information indicating an unlicensed band cell in an inactive state (eg, CIF included in DCI) and activation/deactivation MAC CE requesting activation of an unlicensed band cell. The activation/deactivation MAC CE may be the same as the activation/deactivation MAC CE described with reference to FIG. 12 . The PDCCH (or EPDCCH) may further include scheduling information (eg, an uplink grant) for uplink resources of an unlicensed band cell, scheduling information for downlink resources of an unlicensed band cell, and the like.

The UE may receive PDCCH (or EPDCCH) in subframe #(n+1) of the licensed band cell. The UE may obtain activation request information included in PDCCH (or EPDCCH) by performing descrambling based on "UE-specific U-RNTI (or activation U-RNTI, C-RNTI)". That is, the UE may determine that activation of the unlicensed band cell is requested by checking the activation request information included in the PDCCH (or EPDCCH). For example, the UE may determine that activation of an unlicensed band cell indicated by a CIF included in DCI is requested. Alternatively, the UE may determine that activation of the unlicensed band cell is requested based on the activation/deactivation MAC CE.

Descrambling for PDCCH (or EPDCCH) may be completed within a time corresponding to one subframe. In this case, the UE may activate the unlicensed band cell from the next subframe (ie, subframe #(n+2)). That is, the activation timer may be operated from subframe #(n+2) of the unlicensed band cell. In addition, the UE determines that the subframe in which the SSS-based PUCCH is configured based on the SSS-based PUCCH related information is subframe #(n+2) (ie, the subframe in which the PDCCH (or EPDCCH) including activation request information is configured # (n+1) and subsequent subframes). Accordingly, the UE may transmit a reception response of a PDCCH (or EPDCCH) including activation request information to the base station in the SSS-based PUCCH included in subframe #(n+2) of the licensed band cell. When a reception response of a PDCCH (or EPDCCH) including activation request information is received in an SSS-based PUCCH included in subframe #(n+2) of a licensed band cell, the base station determines that the UE activates the unlicensed band cell. can be judged to be

Meanwhile, the base station may transmit a PDCCH (or EPDCCH) and a PDSCH scheduled by the PDCCH (or EPDCCH) in subframe #(n+4) of the unlicensed band cell. Since the state of the unlicensed band cell is active, the UE can receive PDCCH (or EPDCCH) in subframe # (n + 4) of the unlicensed band cell, and obtain scheduling information from the received PDCCH (or EPDCCH) can do. The UE may receive the PDSCH in subframe #(n+4) of the unlicensed band cell indicated by the scheduling information.

Next, a scheduling method of an unlicensed band cell will be described.

When the self-scheduling method is used, scheduling information for the PDSCH included in subframe #n of the unlicensed band cell may be transmitted through PDCCH (or EPDCCH) included in subframe #n of the unlicensed band cell. When the cross-carrier scheduling method is used, the scheduling information for the PDSCH included in subframe #n of the unlicensed band cell is PDCCH included in subframe #n of the unlicensed band cell and subframe #n of the corresponding licensed band cell ( Alternatively, it may be transmitted through EPDCCH).

Scheduling information (eg, grant) for the PUSCH included in subframe #(n+4) of the unlicensed band cell is the PDCCH included in subframe #n of the licensed band cell or the unlicensed band cell (or, EPDCCH) may be transmitted. Scheduling information for the PUSCH included in subframe #(n+4) of the unlicensed band cell may be included in DCI (eg, DCI having format 0). In this case, the UE may transmit the PUSCH through uplink resources included in subframe #(n+4) of the unlicensed band cell indicated by the scheduling information. However, when subframe #(n+4) of the unlicensed band cell is occupied by another communication node, the UE may transmit the PUSCH as follows.

As a first method, the UE may give up transmission of the PUSCH in subframe # (n + 4) of the unlicensed band cell when subframe # (n + 4) of the unlicensed band cell is occupied by another communication node. In this case, the UE monitors a licensed band cell or an unlicensed band cell to receive a PDCCH (or EPDCCH) including DCI (eg, DCI having format 0) including new scheduling information for the PUSCH. there is. When PDCCH (or EPDCCH) including DCI (eg, DCI having format 0) including new scheduling information for PUSCH is received, UE performs uplink of unlicensed band cell indicated by new scheduling information A PUSCH may be transmitted through a resource.

In the second method, the UE can check the channel state from subframe # (n + 4) to subframe # (n + 4 + N _{UL _Window} ) of the unlicensed band cell, and when the channel state is idle, the unlicensed band The PUSCH may be transmitted through uplink resources of the cell. In this case, the UE may transmit the PUSCH based on scheduling information received through subframe #n of the licensed band cell or the unlicensed band cell. N _{UL_Window} may be preset in the base station and _the UE. Alternatively, N _{UL _Window} may be transmitted to the UE through an RRC message (eg, a newly defined RRC message for an unlicensed band cell). N _{UL_Window} may be set to a maximum transmission period or _a maximum channel occupation time or less. N _{UL _Window} may be an integer greater than or equal to 0. For example, when N _{UL_Window} is 0, the UE transmits the PUSCH in subframe #(n+ ₄ ) of the unlicensed band cell when subframe #(n+4) of the unlicensed band cell is occupied by another communication node. transmission may be abandoned. In this case, the UE monitors a licensed band cell or an unlicensed band cell to receive a PDCCH (or EPDCCH) including DCI (eg, DCI having format 0) including new scheduling information for the PUSCH. there is.

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

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

Although described with reference to the above embodiments, those skilled in the art will understand that the present invention can be variously modified and changed without departing from the spirit and scope of the present invention described in the claims below. You will be able to.

Claims (20)

As a method of operating a user equipment (UE) in a communication network,
Receiving a physical downlink control channel (PDCCH) including downlink control information (DCI) from a base station in subframe n-1 of an unlicensed band;
decoding the DCI using a common radio network temporary identifier (RNTI);
Checking the number of symbols of subframe n of the unlicensed band based on the decoded DCI; and
And determining whether the subframe n is a partial subframe having a length of less than 1 ms based on the number of symbols. The method of claim 1,
The common RNTI is obtained from the base station through radio resource control (RRC) signaling. The method of claim 1,
A cyclic redundancy check (CRC) of the DCI is scrambling based on the common RNTI. The method of claim 1,
The subframe n-1 has a length of 1ms, and the subframe n is the partial subframe having a length of less than 1ms. The method of claim 1,
When consecutive subframes are received from the base station, the subframe n is a start frame among the consecutive subframes. The method of claim 1,
When consecutive subframes are received from the base station, the subframe n is an end subframe among the consecutive subframes. delete As a method of operating a base station in a communication network,
Generating downlink control information (DCI) including information indicating the number of symbols of subframe n of the unlicensed band;
performing scrambling on a cyclic redundancy check (CRC) of the DCI using a common radio network temporary identifier (RNTI); and
Transmitting a physical downlink control channel (PDCCH) including scrambled DCI to user equipment (UE) through subframe n-1 of the unlicensed band,
The DCI further includes information indicating whether the subframe n is a partial subframe having a length of less than 1 ms. The method of claim 8,
The common RNTI is transmitted to the UE through radio resource control (RRC) signaling. The method of claim 8,
The subframe n-1 has a length of 1ms, and the subframe n is the partial subframe having a length of less than 1ms. The method of claim 8,
When consecutive subframes are transmitted to the UE, the subframe n is a start frame among the consecutive subframes. The method of claim 8,
When consecutive subframes are transmitted to the UE, the subframe n is an end subframe among the consecutive subframes. delete As a user equipment (UE) supporting an unlicensed band,
processor; and
A memory in which at least one instruction executed by the processor is stored;
The at least one command,
Receiving a physical downlink control channel (PDCCH) including downlink control information (DCI) from a base station in subframe n-1 of the unlicensed band;
decoding the DCI using a common radio network temporary identifier (RNTI);
Checking the number of symbols of subframe n of the unlicensed band based on the decoded DCI; and
The UE configured to determine whether the subframe n is a partial subframe having a length of less than 1 ms based on the number of symbols. The method of claim 14,
The common RNTI is obtained from the base station through radio resource control (RRC) signaling. The method of claim 14,
A cyclic redundancy check (CRC) of the DCI is scrambled based on the common RNTI. The method of claim 14,
The subframe n-1 has a length of 1ms, and the subframe n is the partial subframe having a length of less than 1ms. The method of claim 14,
When consecutive subframes are received from the base station, the subframe n is a start frame among the consecutive subframes. The method of claim 14,
When consecutive subframes are received from the base station, the subframe n is an end subframe among the consecutive subframes. delete

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