WO2016129809A1 - Channel occupancy method in spectrum sharing wireless communication system - Google Patents

Abstract

The present invention relates to channel occupancy in a spectrum sharing wireless communication system, and provides: 1) a method for configuring and transmitting an unlicensed band frame structure using a special subframe and a preamble of a physical random access channel (PRACH) in order to occupy resources in an unlicensed band without collision or interference from an unlicensed band system such as WiFi, etc.; 2) a signal transmission method for occupying a channel in a guard period (GP) interval in the case of a terminal to which an uplink is assigned, so that an unlicensed band system may not occupy the channel first; and 3) a scheduling method of uplink resources from the perspective of a base station and a terminal, in consideration of discrete resource occupancy circumstances of an unlicensed band, by separating cross carrier scheduling utilizing a licensed band from self scheduling utilizing a downlink of an unlicensed band.

Description

Channel occupancy method of common frequency wireless communication system

The present invention relates to a channel occupancy method of a wireless communication system, and in particular, a licensed band wireless communication system according to a protocol such as Long Term Evolution (LTE) is an unlicensed band system and an unlicensed license according to a protocol such as a wireless local area network (WLAN). The present invention relates to a channel occupancy method of a frequency coexisting wireless communication system when a band is to be used jointly.

Recently, the 3rd Generation Partnership Project (3GPP) is developing a standard technology for utilizing the LTE system operating in the existing licensed band in the unlicensed band of 5GHz. Scenarios for aggregating and operating carriers in licensed and unlicensed bands are considered first.Duplex in licensed and unlicensed bands also consider modes considering both downlink or uplink and downlink of FDD (Frequency Division Duplexing). Doing. In this regard, the LTE system to be operated in the unlicensed band considers a resource access method considering List-Before-Talk (LBT) in order to occupy fairness resources between the existing wireless fidelity (WiFi) system and other LTE cells. By defining the duty cycle (duty cycle), etc., it is expected to limit the continuous occupancy of resources by a specific cell.

When the LTE system transmits data in a subframe boundary unit in an unlicensed band, signal transmission for channel occupancy is necessary under certain conditions so that the WiFi system does not occupy the channel first. In case of downlink, a base station (eNodeB) may transmit a defined signal, but in case of uplink, a plurality of terminals should transmit a signal. In the existing LTE Time Division Duplexing (TDD) system, a guard period (GP) is provided so that uplink (UL, uplink) signals arrive at a base station at the same time. It is defined to transmit a signal accordingly. If the WiFi system intends to occupy a channel during this GP period, it may be difficult for the LTE system to transmit data.

Accordingly, the present invention has been made to solve the above-described problems, and an object of the present invention is to, in the channel occupancy of a frequency shared wireless communication system, 1) resources of the unlicensed band without collision or interference with unlicensed band systems such as WiFi The present invention provides a structure of a unlicensed band frame using a special subframe and a preamble configuration and transmission method of a PRACH (Physical Random Access Channel) channel in order to occupy the network. 2) An uplink is allocated so that the unlicensed band system does not occupy the channel first. In case of a UE, a signal transmission method for occupying a channel in a GP (Guard Period) section is provided. Also, 3) a UE is classified into Cross Carrier Scheduling using a licensed band and Self Scheduling using a downlink of an unlicensed band. A scheduling method of uplink resources from a base station and a terminal point of view considering a non-contiguous resource occupancy situation of There used to.

Technical problems of the present invention are not limited to the technical problems mentioned above, and other technical problems not mentioned will be clearly understood by those skilled in the art from the following descriptions.

First, to summarize the features of the present invention, the channel occupancy method for using the unlicensed band as a secondary in the wireless communication system using the licensed band according to an aspect of the present invention for achieving the above object to use A downlink pilot time slot (DwPTS) for transmission of a DL signal, a guard period (GP) of variable length, between a downlink (DL) subframe and an uplink (UL) subframe for channel occupancy of an unlicensed band Using a special subframe consisting of an uplink pilot time slot (UpPTS) section for signal transmission, the base station does not transmit a signal in the DwPTS section (No-Tx), or transmits control signals, data transmission, carrier sensing, Transmitting a signal to a user terminal using the interval for any one or more of back-offs; And transmitting, at the user terminal, a physical random access channel (PRACH) preamble for UL synchronization in a consecutive period of the No-Tx interval, the GP interval, and the UpPTS interval.

The user terminal may stop transmission of the PRACH preamble at a symbol or subframe boundary.

When the DwPTS interval is No-Tx, it includes a case where user terminals transmit the PRACH preamble from before the GP interval.

The user terminal includes a case in which the PRACH preamble is transmitted only in the GP interval or the UpPTS interval.

The user terminal includes a case of transmitting the PRACH preamble using a part of the unlicensed band or the entire unlicensed band.

In order to occupy the channel of the unlicensed band, the user terminal may be configured such that the No-Tx section or the rest period by the GP is not occupied by the unlicensed band system after the end of the signal transmission of the DwPTS. The PRACH preamble or the UL subframe may be transmitted after a fixed offset of a predetermined length or less is provided within a GP interval.

The user terminal may transmit the PRACH preamble to a corresponding channel of the unlicensed band according to the index information from the base station that scheduled the unlicensed band uplink resource.

When the base station informs the PRACH channel allocation information of the unlicensed band including the index information using a predetermined message or a PDCCH signal, the user terminal corresponds to the unlicensed band channel corresponding to the subframe index of the allocated unlicensed band. The PRACH preamble may be transmitted by occupying.

The base station may transmit the message or the PDCCH signal in a licensed or unlicensed band.

The base station further informs the bit information indicating whether the number of consecutive UL subframes after the UpPTS through the PRACH channel allocation information, the user terminal is assigned to the first UL subframe after the UpPTS In this case, the PRACH preamble may be transmitted in consecutive periods among the No-Tx interval, the GP interval and the UpPTS interval.

When the user terminal does not occupy the corresponding unlicensed band channel in the subframe index of the allocated unlicensed band, the user terminal may access and occupy the corresponding unlicensed band channel within a UL window section of a predetermined length.

According to another aspect of the present invention, in a wireless communication system using a licensed band, a channel occupancy method for coexisting with an unlicensed band system and using an unlicensed band as a secondary includes a DL (Downlink) subframe and an UL (Uplink) subframe. Between frames, a special subframe consisting of a downlink pilot time slot (DwPTS) for transmitting a DL signal, a guard period (GP) for variable length, and an uplink pilot time slot (UpPTS) for a UL signal transmission are used. Determining, by the base station, either Self Scheduling or Cross Carrier Scheduling to occupy an uplink channel of the band;

Transmitting, by the base station in self scheduling, information on an unlicensed band UL channel allocated to the user terminal to the user terminal in a special subframe in an unlicensed band; And receiving, by the base station, at uplink data by attempting connection with the user terminal in an unlicensed band within a predetermined UL window period in cross carrier scheduling.

When the base station occupies the UL channel in advance in Cross Carrier Scheduling, the DwPTS signal including information about the unlicensed band UL channel within the UL window period is transmitted based on the transmission from the licensed band to the user terminal. Uplink data may be received.

When the base station does not occupy the UL channel in advance in the cross carrier scheduling, uplink data based on detecting a physical random access channel (PRACH) preamble of an unlicensed band received from the user terminal within the UL window period Can be received.

In the self scheduling, when the user terminal is allocated to the first UL subframe after the UpPTS, the PRACH preamble may be transmitted in consecutive periods of the No-Tx interval, the GP interval, and the UpPTS interval. .

In the Cross Carrier Scheduling, when the user terminal previously occupies the UL channel notified from the base station, the PRACH preamble is transmitted to the special subframe in the special subframe within the UL window period notified from the base station. The uplink data may be transmitted to the base station.

In the Cross Carrier Scheduling, when the user terminal does not previously occupy the UL channel notified from the base station, the DwPTS signal is received from the base station within the UL window period notified from the base station, and the PRACH Preamble Based on the transmission to the base station, the uplink data may be transmitted to the base station.

In addition, in a wireless communication system using a licensed band according to another aspect of the present invention, a channel occupancy method for coexisting with an unlicensed band system and using an unlicensed band as a secondary includes a DL (Downlink) subframe and an UL (Uplink) subframe. Between frames, a special subframe consisting of a downlink pilot time slot (DwPTS) for transmitting a DL signal, a guard period (GP) for variable length, and an uplink pilot time slot (UpPTS) for a UL signal transmission are used. Determining, by the base station, one of Self Scheduling or Cross Carrier Scheduling to occupy a downlink channel of a band; in the Self Scheduling, the base station includes a signal for occupying an unlicensed band resource at a predetermined transmission time point. Transmitting one subframe data to a user terminal through an unlicensed band; And subframe data generated by the base station in a cross carrier scheduling, including an unlicensed band resource occupancy signal at a predetermined transmission time when the unlicensed band system does not occupy the unlicensed band to a user terminal through an unlicensed band and a licensed band. Transmitting.

In the Cross Carrier Scheduling, after checking the transmittable time, the data is loaded in all slots of the corresponding subframe, or the subframe data is generated so that the data is loaded only in the second slot of the corresponding subframe.

The user terminal may receive and demodulate unlicensed band downlink data based on the unlicensed band resource occupancy signal for receiving and detecting an unlicensed band downlink signal from the base station during an unlicensed band activation period.

According to the channel occupancy method of the frequency-shared wireless communication system according to the present invention, the unlicensed band frame structure of the present invention using a special subframe and the preamble configuration and transmission method of the PRACH (Physical Random Access Channel) channel are unlicensed bands such as WiFi. It can occupy unlicensed resources without conflict or interference with the system.

In addition, according to the signal transmission method of the present invention for occupying a channel in a GP (Guard Period) section, an uplink- allocated terminal does not allow an unlicensed band system to occupy a channel first. It is possible to reliably occupy this unlicensed band channel.

In addition, the system is classified into Cross Carrier Scheduling using a licensed band and Self Scheduling using a downlink of an unlicensed band. The frequency coexistence wireless communication system of the present invention can stably occupy non-contiguous unlicensed band resources.

1 shows a special subframe of an existing LTE system.

2 shows a configuration table of a special subframe of an existing LTE system.

3 is a view for explaining an environment of a frequency shared wireless communication system according to an embodiment of the present invention.

4A shows a special subframe according to an embodiment of the present invention.

4B shows a case in which a UL subframe is included in a special subframe according to an embodiment of the present invention.

5 to 8 show various embodiments of DwPTS in a special subframe of the present invention.

9 to 12 show configuration examples of UpPTS and PRACH of the special subframe of the present invention.

13A and 13B illustrate a PRACH preamble applied to the present invention.

14 shows a fixed length PRACH preamble sequence applied to the present invention.

15 shows a new variable length PRACH preamble according to an embodiment of the present invention.

16 shows examples for describing a PRACH preamble transmission time point according to an embodiment of the present invention.

17 shows an example of a T-PRACH configuration of an unlicensed band special subframe without downlink data transmission according to an embodiment of the present invention.

18 shows an example of a Full-T PRACH configuration of an unlicensed band special subframe without downlink data transmission according to an embodiment of the present invention.

19 shows an example in which PRACH information to be used by a UE is delivered directly or indirectly from a PCell PDCCH according to an embodiment of the present invention.

20 is an example of PRACH information to be used indirectly by a UE from a PDCCH to which a PCell PUSCH is allocated according to an embodiment of the present invention.

21 is another example of PRACH information to be used indirectly by a UE from a PDCCH to which a PCell PUSCH is allocated according to an embodiment of the present invention.

22 illustrates examples of a time point and a signal for transmitting uplink data according to transmission time information of a DwPTS according to an embodiment of the present invention.

23 shows an uplink resource allocation sequence of an NB in a frequency common wireless communication system according to an embodiment of the present invention.

24 is a flowchart illustrating a UL data transmission sequence of a UE in a frequency shared wireless communication system according to an embodiment of the present invention.

FIG. 25 is a diagram illustrating downlink channel occupancy and data transmission sequence of an NB in a frequency common wireless communication system according to an embodiment of the present invention. FIG.

FIG. 26 illustrates a downlink data reception order of a UE in a frequency shared wireless communication system according to an embodiment of the present invention.

27A to 27L further illustrate various embodiments of DwPTS in addition to FIGS. 5 to 8 in a special subframe of the present invention.

28A-28J further illustrate various embodiments of UpPTS and PRACH in addition to FIGS. 9-12 in the special subframe of the present invention.

Hereinafter, some embodiments of the present invention will be described in detail through exemplary drawings. In adding reference numerals to the components of each drawing, it should be noted that the same reference numerals are assigned to the same components as much as possible even though they are shown in different drawings. In addition, in describing the embodiments of the present invention, if it is determined that the detailed description of the related well-known configuration or function interferes with the understanding of the embodiments of the present invention, the detailed description thereof will be omitted.

In describing the components of the embodiments of the present invention, terms such as first, second, A, B, (a), and (b) may be used. These terms are only for distinguishing the components from other components, and the nature, order or order of the components are not limited by the terms. In addition, unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art. Terms such as those defined in the commonly used dictionaries should be construed as having meanings consistent with the meanings in the context of the related art, and shall not be construed in ideal or excessively formal meanings unless expressly defined in this application. Do not.

1 shows a special subframe of an existing LTE system. 2 shows a configuration diagram of a special subframe of an existing LTE system.

1 and 2, the special subframe of the existing LTE system, as shown in Figure 1 DwPTS of the DL (Downlink, downlink) signal, UpPTS of the UL (Uplink, uplink) signal, and uplink / downlink propagation It is composed of GP (Guard period) considering the propagation time.

Downlink Pilot Time Slot (DwPTS) and GP are composed of the number of Orthogonal Frequency Division Multiplexing (OFDM) symbols as shown in FIG. 2 according to the Cyclic Prefix (CP) configuration conditions, and Uplink Pilot Time Slot (UpPTS) is configured as one or two OFDM symbols. It is composed.

The DwPTS is used to transmit a control signal (Cntl) and to transmit data such as a primary synchronization signal (PSS), a physical downlink shared channel (PDSCH), and a reference signal. UpPTS is used to transmit a Physical Random Access Channel (PRACH) for UL synchronization and a Sounding Reference Signal (SRS) for UL channel state estimation.

GP is a fixed time from the base station (NB) point of view, but from the viewpoint of each user terminal (UE) is a different length by the radio wave arrival time according to the distance between the NB and the UE. That is, since the UE must transmit the UL transmission signal to the NB at the correct timing, in the NB, the far-away UE transmits the signal first compared to the UE close to the NB.

3 is a view for explaining the environment of the frequency shared wireless communication system 100 according to an embodiment of the present invention.

As shown in FIG. 3, the common frequency use wireless communication system 100 according to an embodiment of the present invention is a wireless local area network (WLAN) according to a protocol such as a base station (NB), user terminal (s) (UE), and WiFi. ) Systems and the like.

Here, the NB may be in the form of a mobile communication base station Node B, an eNB, a home-eNB, a relay station, a remote radio head (RRH), an access point (AP), or the like. The NB relays a UE in a macrocell to a mobile communication service through a backhaul in a licensed band according to a mobile communication protocol such as Long Term Evolution (LTE).

In addition, the WLAN system may be in the form of an access point (AP) that forms a small cell such as a pico cell, a femto cell, and the like. The WLAN system relays a UE in the small cell using a license-free band (for example, 5 GHz band) according to a protocol such as WLAN to receive WLAN communication services such as the Internet through a sidehaul.

4A shows a special subframe according to an embodiment of the present invention. 4B shows a case in which a UL subframe is included in a special subframe according to an embodiment of the present invention.

As shown in FIG. 4A, in the common frequency use wireless communication system 100 according to an exemplary embodiment of the present invention, in order to coexist with an unlicensed band system and use an unlicensed band as a secondary, a licensed assisted access (LAA), Special The subframe includes a DwPTS of a DL signal, an UpPTS of an UL signal, and a GP (Guard period) in consideration of propagation time of an uplink / downlink. In the DwPTS period, in addition to the transmission of a control signal such as a preamble, a physical downlink control channel (PDCCH), and a data transmission such as a PDSCH, a period for not transmitting a signal (No-Tx), carrier sensing for sensing a channel ( It is used for any one or more of the Carrier Sensing section, the back-off section for accessing the channel through the back-off counter.

The presence, location, and size (length) of each section for each function constituting the DwPTS section may be variously made. The GP length may also be variable, and its length may be known according to predetermined configuration information, or may be calculated computationally when the DwPTS and UpPTS lengths are defined. In the GP interval, the UE may perform a Clear Channel Assessment (CCA) or Extended CCA function for searching for an optimal channel.

An example of DwPTS configuration of a special subframe for unlicensed band usage in the frequency coexistence wireless communication system 100 of the present invention includes FIG. 5 (carrier sensing, back-off, reserved signal (or preamble) section in a DL subframe. , DwPTS with control signal / data), FIG. 6 (DwPTS with control signal / data), FIG. 7 (DwPTS with carrier sensing, back-off, preamble section), FIG. 8 (DwPTS with No-Tx, Reserved Signal) (or Preamble), PDCCH, PDSCH), and more embodiments are shown in FIGS. 27A-27L. Referring to FIGS. 27A through 27L, control signals such as a PDCCH, data such as a PDSCH and a reference signal, carrier sensing in a DL subframe and a DwPTS, back-off, reserved signal (or preamble), and no-tx. It will be appreciated that combinations comprising one or more of these may be suitably dispersed and used. The uplink channel occupancy signal Reserved Signal (or Preamble), a signal used for the DL may include a signal for indicating that the resource for the UL or DwPTS.

UpPTS is used to transmit a Physical Random Access Channel (PRACH) preamble for UL synchronization and a Sounding Reference Signal (SRS) for UL channel state estimation. UpPTS may be composed of a plurality of OFDM symbols, and additionally, UL subframes may be included after UpPTS as shown in FIG. 4B, and transmission of data such as PUSCH (Physical Uplink Shared Channel) and PUCCH (Physical Uplink Control) through UL subframes. Control signal such as a channel) can be transmitted. PRACH is a channel for transmitting a PRACH preamble.

In order to occupy the channel of the unlicensed band, the PRACH preamble may be transmitted during the GP after the DwPTS, and the transmission time may be configured to be shorter than the minimum time required for the WLAN system such as WiFi to occupy the channel. UpPTS may be composed of an SRS and a PRACH, and the PRACH may be allocated for various purposes unlike the PRACH of the existing license band. After UpPTS, one or more UL subframes may be allocated, and data may be transmitted to UL from a second slot of two slots of the special subframe according to the size of DwPTS. In this case, RBs of consecutive uplink slots and subframes may be allocated to the same UE.

An example configuration of UpPTS and PRACH of a special subframe for unlicensed band use in the frequency common wireless communication system 100 of the present invention is shown in Figs. 9 to 12, and more embodiments are shown in Figs. 28A to 28J. It is.

In the common frequency use wireless communication system 100 of the present invention, as shown in FIG. 9, a general PRACH in which a plurality of UEs UE1, UE2, and UE3 can use an entire section of a special subframe for UL channel access is possible. T-PRACH (Truncated-PRACH) capable of using a GP or UpPTS section, Synch-PRACH for periodic UL synchronization, etc. may be used.

T-PRACH is a channel that can be used for each UE to occupy resources in the UpPTS and GP intervals. In general, the PRACH is configured to be larger than the SC-FDM symbol size or may not be transmitted according to an uplink symbol boundary according to a transmission time difference. Therefore, the PRACH is a channel capable of stopping transmission on a sample basis. The PRACH may be transmitted in the form of PRACH Format (Configuration) 0,1,2,3,4 (see FIGS. 13A and 13B), and the T-PRACH may be allocated to an UpPTS or may be transmitted only to a GP. , PRACH preamble transmission may be stopped in consideration of resource allocation with SRS and Uplink TS in the UpPTS. That is, the UE may stop transmission at the symbol or subframe boundary in the PRACH Preamble transmission of the unlicensed band. The SYNCH-PRACH is transmitted in an UpPTS section of the same RB as the T-PRACH or consists of an RB defined separately from the SRS in the UpPTS, and can be used to periodically perform unlicensed uplink synchronization.

FIG. 10 illustrates a case where a plurality of UEs UE1, UE2, and UE3 simultaneously transmit PRACH preambles to a plurality of PRACHs. Even when the PRACH is transmitted in the DwPTS of FIG. 10, the T-PRACH and the SYNCH-PRACH may be transmitted in the UpPTS period.

FIG. 11 is a schematic diagram assuming only a general PRACH, indicating that UEs may transmit a PRACH preamble prior to a GP interval when the DwPTS before the GP is a No-Tx interval. This may be the case when the last section is No-Tx after DL data is transmitted to the DwPTS, or when the UEs randomly access and occupy the channel without any transmission to the DwPTS. UEs can transmit a PRACH preamble using consecutive periods among No-Tx intervals, GP intervals, and UpPTS intervals.

12 shows that a PRACH is allocated to an unlicensed band full channel rather than some subbands. In T-PRACH, a UE transmits a new PRACH Preamble, a UE transmits a plurality of PRACH preambles, or a plurality of UEs. Preamble can be transmitted.

In other words, the UE of the present invention, as shown in Figure 13a and 13b, CP (Cyclic Prefix), Sequence, GT (Guard Time) in the PRACH Format (Configuration) 0, 1, 2, 3, 4 of the licensed band, such as the existing LTE ), The PRACH preamble having a preamble length and the like can be transmitted. In addition, as shown in Figure 14, the UE of the present invention, SC-FDM (Single-carrier Frequency-division Multiplexing) symbol length of the new configuration (new configuration) generated by allocating samples to 15KHz subcarrier interval (1 / 15k) It is possible to transmit PRACH preambles in a cyclic manner (Cyclic) in the form of a sequence (e.g., 2048 samples) (see FIG. 14) or a sequence in which a predetermined variable sample length (e.g., a natural number N samples) is added thereto. have. That is, the conventional PRACH preamble is configured by defining the subcarrier spacing smaller than the normal 15KHz spacing, in the present invention can configure a PRACH preamble of 15KHz subcarrier spacing and use it cyclically.

Here, the sequence may be an Nzc-point Zadoff-Chu sequence and may be generated by all or part of information defined by a system information block of the NB. Such a new configuration may be a PRACH preamble generated using a plurality of RBs, rather than a PRACH preamble constrained by an existing 6RB (Resource Block). Therefore, it is also possible to generate a preamble signal having the full channel bandwidth of the unlicensed band.

16 shows examples for describing a PRACH preamble transmission time point according to an embodiment of the present invention.

Referring to FIG. 16, since the PRACH is a channel through which the UE randomly accesses a radio resource, the UE may transmit the PRACH preamble within a predetermined time based on a time point when the signal transmission of the DwPTS is terminated. Accordingly, in the unlicensed band, UEs may have a predetermined length, for example, within a GP interval from the termination time point such that the No-Tx interval or the idle period by the GP after the end of signal transmission of the DwPTS is not occupied by the WLAN system. It is possible to transmit a PRACH preamble or an uplink subframe after a fixed offset of DIFS (Distributed Interframe Space) length (34 μs) or less.

The T-PRACH is a channel through which a preamble generated by an existing configuration or a new configuration is transmitted during a period of No-Tx of a GP or a DwPTS. As shown in FIGS. 9 and 10, the T-PRACH stops preamble transmission at an UpPTS start point or a symbol unit boundary of an UpPTS. Means a PRACH channel. SRS and Synch-PRACH may be allocated to the UpPTS section, and PRACH preamble transmission may be stopped in the UpPTS section even when the PRACH Preamble signal is longer than the UpPTS section.

Synch-PRACH is for the purpose of periodic synchronization of the uplink of the unlicensed band and is similar to the conventional PRACH Preamble Configuration 4 (see FIG. 13B). However, according to the present invention, the preamble to be defined and transmitted as Synch-PRACH may be configured 4 and may transmit a new preamble sequence (see FIGS. 14 and 15). The unlicensed band uplink may belong to the same technical architecture group (TAG) as the uplink Timing Advance of the licensed band, so the approximate time synchronization can be set to the preamble as before, but to compensate for errors due to the characteristics of the channel, Synch- The PRACH may be transmitted.

The PRACH channel is a channel for randomly selecting and transmitting a preamble by the UE. For PRACH transmission in the unlicensed band, channel transmission power and PRACH resources must be determined in advance.

In the PRACH resource, six consecutive RBs constitute one channel, or in the case of New PRACH Preamble (see FIGS. 14 and 15), a predetermined total RB or multiple RBs of 6 RB or more may be configured as PRACH channels. Although the time domain of the PRACH channel is allocated to the UpPTS interval and the UE should perform timing advance, the T-PRACH may be allocated only to the GP interval before the UpPTS. If there is an RB to which an SRS is allocated in the UpPTS, it may be defined that a T-PRACH is allocated to a GP interval. The UE may randomly select all or some subbands of the PRACH resources and transmit preambles, and may provide index information (eg, UCI, uplink control information, uplink control information) of the PDCCH from the NB that has scheduled the unlicensed band uplink resource. It may be utilized to identify and apply a PRACH channel index for each UE. The UE may calculate the PRACH channel through the PDCCH information. The NB may determine a PRACH preamble to be transmitted among the Normal PRACH, T-PRACH, and Synch-PRACH, or the UE may arbitrarily determine and transmit one of three PRACHs. For example, the T-PRACH may be transmitted in the No-Tx or GP interval and the Synch-PRACH may be transmitted in the UpPTS interval (see FIGS. 17 and 18).

Alternatively, the NB may designate a PRACH channel through a predetermined message. In this case, each UE may be statically allocated, and a UE not allocated with UL may transmit a T-PRACH if necessary. In the case of Europe, 80% or more of the total channel bandwidth must be occupied, so UEs may transmit the T-PRACH in the full band (Full-T PRACH) without allocating PRACH resources for the T-PRACH (see FIG. 18). Alternatively, PRACH resources may be allocated in every 6RB unit, and a UE to transmit a preamble may be designated for each PRACH.

17 and 18 illustrate a T-PRACH configuration example of a new special subframe considering only the case of uplink transmission without downlink data transmission. This indicates a structure in which UEs can transmit a PRACH preamble and uplink resources after transmitting a channel reserved signal after performing carrier sensing and back-off by the NB during DwPTS.

As described above, when the NB prioritizes resource occupancy in the present invention, the PRACH Preamble may be transmitted by the UE after the downlink signal ends and before the WLAN system occupies the channel. In addition, when each UE needs to occupy an uplink resource, channel sensing and / or back-off may be performed as necessary and a PRACH preamble may be transmitted. At this time, it may occupy the entire channel bandwidth (Full-T PRACH), or may occupy only part of the subbands and transmit.

Further, depending on the manner in which UL resources are composed of a plurality of consecutive subframes (uplink bursts), and resources of the UE scheduled in the bursts are all allocated to the first subframe of the burst, the UE is a fixed resource or subframe. The PRACH preamble may be transmitted according to a specified pattern for each frame. In this case, the NB may be informed of the number of subframes to be used during the uplink burst through the UL grant information. One of the methods is to transmit the number of subframes in the UCI information of the PDCCH.

If random back-off is required before UpPTS transmission, since different UEs transmit signals differently, the NB may not transmit a response signal according to the detection of another UE that is not correct, and thus the same back-off value to the UEs. Can be used. To this end, when allocating resources, the NB may inform all scheduled UEs of a back-off counter value.

As described above, the PRACH channel for the UE to transmit the preamble may be randomly selected by the UE, or may inform the channel index through the PDCCH in the NB. In case of using the PDCCH, the PRACH channel may be directly allocated in the PDCCH, the location information of the uplink PUSCH (in the next subframe), or the index information (eg, UCI, Uplink Control Information, uplink control information) of the PDCCH scheduling the PUSCH. It can be determined using the information.

19 shows an example in which PRACH information to be used by a UE is delivered directly or indirectly from a PCell PDCCH according to an embodiment of the present invention. 20 is an example of PRACH information to be used indirectly by a UE from a PDCCH to which a PCell PUSCH is allocated according to an embodiment of the present invention. 21 is another example of PRACH information to be used indirectly by a UE from a PDCCH to which a PCell PUSCH is allocated according to an embodiment of the present invention.

19 to 21, a PRACH channel is allocated according to whether a cell of a PCell (Primary Cell) of a licensed band or a SCell (Secondary Cell) of an unlicensed band is used. The scheduling scheme in the NB for notifying the PDCCH may be different.

For example, when the NB schedules in the PCell and informs the UE of PRACH channel allocation information of an unlicensed band in which a predetermined message or index information is included in a PDCCH signal, the UE attaches to a subframe index of the allocated unlicensed band. PRACH Preamble can be transmitted by occupying the corresponding channel, but when the channel is difficult to occupy in the subframe index of the actually allocated unlicensed band, the unlicensed band channel is accessed in the uplink in the UL window section of a predetermined length (eg, UpPTS / UL section) to occupy (see Figs. 19 and 20). If, as shown in FIG. 21, a special subframe is configured after the DL subframe in the unlicensed band and then allocated a UL subframe, the NB unlicensed band to the UE with a predetermined message in the unlicensed band SCell or index information of the PDCCH. May notify the PRACH channel assignment of the.

In addition, as shown in FIG. 20, UEs may designate and occupy channels of uplink subframes after the unlicensed band UpPTS according to parameters defined in the system. In addition, after NB occupies the unlicensed band, UEs may transmit data by occupying the same channel for a certain number of subframes.

If the NB informs the different UEs of the PRACH channel allocation information for each subframe after the UpPTS, the NB may further include a bit for acknowledging the first of consecutive UL subframes after the UpPTS, or a bit information for acknowledging the order thereof. Can be notified. In this case, according to the informed information, the UE checks the position of the UL subframe allocated to the UE from the special subframe (PDCCH, etc.), and if it is allocated to the first UL subframe after UpPTS, as described above, No-Tx, The PRACH preamble may be transmitted in a GP or UpPTS period.

22 illustrates examples of a time point and a signal for transmitting uplink data according to transmission time information of a DwPTS according to an embodiment of the present invention.

When using the unlicensed band in the frequency common use wireless communication system 100 of the present invention, in order to solve the hidden node problem, Special Subframe may be utilized as Request To Send (RTS), Clear To Send (CTS), and the like. Conceptually, the DwPTS interval signal may be used as a signal for RTS (notifying to send data) and the UpPTS interval signal may be used as a signal for CTS (notifying for sending data).

To this end, it is possible to insert a predetermined signal that can be quickly detected by all UEs in the DwPTS. The NB may designate a UE to which UpPTS should be transmitted when receiving a corresponding DwPTS only for a specific UE. As illustrated in FIG. 22, when the UE may receive data from the NB in a DL subframe according to a predetermined signal of the DwPTS, and according to transmission time information included in the predetermined signal of the DwPTS, the UE should transmit uplink data. And the corresponding signal (UpPTS or UL subframe signal) may be applied differently.

FIG. 23 is a diagram illustrating an uplink resource allocation order of an NB in a frequency common wireless communication system 100 according to an embodiment of the present invention.

Referring to FIG. 23, first, an NB may activate or deactivate an unlicensed band cell to a UE that will utilize an unlicensed band. The NB determines that allocation of an uplink channel is necessary for the UE to use the unlicensed band according to a predetermined algorithm (S110).

At this time, the NB determines any one of Self Scheduling or Cross Carrier Scheduling, and transmits corresponding information to the UE to request activation of an unlicensed band cell (S120).

If the scheduling scheme is Self Scheduling (S130), NB is a UL resource in a (N + k + i) subframe of the unlicensed band in a predetermined subframe of the unlicensed band, for example, the (N + i) th subframe. And allocate a (N + k + i-1) subframe between the DL and the UL as a special subframe (S140). Here, N and k may be positive integers, and i may be 0 or positive integers.

The NB may notify the UE of the information allocated in the DwPTS section in the Special Subframe, which is the (N + k + i-1) subframe, through a predetermined message or a PDCCH signal in the unlicensed band (S141). At this time, when the UL resource is notified, each UE is informed of the number of subframes to be continuously occupied with the corresponding RB information, so that each UE can use multiple UL subframes in one scheduling. Each UE detects, receives, and stores the signals defined above in the activated unlicensed band cell, transmits the PRACH preamble, SRS as described above to the NB, occupies the unlicensed band, and acquires UL data through the corresponding unlicensed band occupation. Can be transmitted. The NB may receive PRACH Preamble and SRS to determine time synchronization and channel state to receive and demodulate data.

If the scheduling scheme is Cross Carrier Scheduling (S130), NB is UL in a predetermined subframe of the licensed band, for example, in the (N + i) th subframe, in the (N + m + i) subframe of the unlicensed band. A resource (PUSCH channel) is allocated (S150). Here, m may be a positive integer. In this case, UL Window (subframe / symbol of a = 1 or more) may be determined as necessary. The NB may inform the UE of the determined UL Window and UL resource (PUSCH channel) information through a predetermined message.

Thereafter, the NB senses the allocated unlicensed band channel (UL resource) and occupies the channel in advance (or occupied) from (N + i) to (N + m + i-1) subframes (S160). As in steps S170 to S175, attempts are made from (N + i) to UL Window (a) while increasing by 1 from n = 0, performing carrier sensing and back-off functions, and data transmission is normally performed according to the environment. If no (UE does not receive the DwPTS), the above scheduling is canceled and the corresponding information is deleted (S176).

When data transmission can be normally performed (S173), the NB may notify the UE of UL resource (PUSCH channel) information, etc. allocated as above in the DwPTS section through a predetermined message or a PDCCH signal (S177). At this time, when the UL resource is notified, each UE is informed of the number of subframes to be continuously occupied with the corresponding RB information, so that each UE can use multiple UL subframes in one scheduling. The UE may not transmit data in the allocated subframe, but may transmit data in the entire allocated subframe or may transmit data only in the second slot.

Thereafter, the NB may receive the SRS from the UE, determine the channel state, and receive and demodulate uplink data of the next UL subframe (S178).

Meanwhile, when sensing an unlicensed band channel (UL resource) allocated by the NB and failing to occupy the channel in advance from (N + i) to (N + m + i-1) subframes (S160), steps S180 to S184. As shown in FIG. 5, when n = i is increased from 1 to (1 + i) to UL Window (a), when the PRACH preamble is not received from the UE in the DwPTS period, the above scheduling is canceled and the corresponding information is deleted ( S185).

When receiving the unlicensed PRACH preamble (see S267) from the UE in the special subframe period (S182), the NB receives the SRS in the UpPTS period from the UE to determine the channel state to receive uplink data of the next UL subframe. It can be demodulated (S186).

24 is a flowchart illustrating an uplink data transmission sequence of a UE in a frequency shared wireless communication system 100 according to an embodiment of the present invention.

Referring to FIG. 24, first, upon receiving an unlicensed band cell activation request (see S120) from an NB, the UE transmits a corresponding response (S210).

If it is determined that the scheduling scheme is not Cross Carrier Scheduling (S220), the UE receives an unlicensed band downlink PDCCH signal (see S140 and S141) from the NB (S230).

At this time, in case of self scheduling (S231), if the UE is allocated the first UL subframe after the DL (first UL subframe after the Special Subframe) (S232), as described above in the Special Subframe, No-Tx interval, GP interval, In operation S233, the PRACH preamble is transmitted to the NB using a consecutive period of the UpPTS period. Accordingly, the UE may transmit SRS, UL data, etc. through the corresponding unlicensed band occupation (S234).

On the other hand, in the case of Cross Carrier Scheduling by determining the scheduling scheme (S220), the UE receives a predetermined message (see S150) from the NB and confirms scheduling information (S240). That is, the UE may identify the UL Window (a) and identify (or calculate) UL resource (PUSCH channel) information, that is, an uplink subframe initial allocation position (N + m + i) subframe.

Thereafter, when the UE senses the allocated unlicensed band channel and occupies the channel in advance (or occupied) from (N + i) to (N + m + i-1) subframes (S250), S260 to S265 As in the step, when performing the carrier sensing and the back-off function from (N + i) to UL Window (a) while increasing by 1 from n = 0, if the data transmission cannot be normally performed according to the environment (NB If the PRACH preamble is not received), storage of the corresponding scheduling information is canceled and then deleted (S266).

If data transmission can be normally performed (S163), UEs can transmit a PRACH Preamble (eg, normal PRACH T-PRACH, Sync-PRACH) to the NB (S267). Subsequently, the UE may transmit an SRS and the like in addition to the PRACH preamble in the UpPTS period to the NB, and may transmit uplink data of the allocated UL subframe to the NB (S268).

On the other hand, if the UE senses the allocated unlicensed band channel and does not occupy the corresponding channel from (N + i) to (N + m + i-1) in advance (S250), as in steps S270 to S274, n If the DwPTS is not received from the NB from (N + i) to UL Window (a) while increasing from 0 to 1, the storage of the corresponding scheduling information is canceled and deleted (S275).

When receiving the DwPTS (see S177) from the NB (S272), the UE transmits the PRACH Preamble (eg, T-PRACH, Sync-PRACH) to the NB (S276), after which the UE PRACH Preamble in the UpPTS period to the NB In addition, the SRS may be transmitted and uplink data of the allocated UL subframe may be transmitted to the NB (S268).

FIG. 25 is a diagram illustrating downlink channel occupancy and data transmission sequence of an NB in a frequency common wireless communication system according to an embodiment of the present invention. FIG.

Referring to FIG. 25, first, when the NB determines that unlicensed band downlink resource allocation is necessary (S310), the NB determines one of Self Scheduling or Cross Carrier Scheduling, and transmits the relevant information to the UE to exempt the license. Request activation of the band cell (S320).

If the scheduling scheme is Self Scheduling (S330), the NB performs carrier sensing on whether the unlicensed band can be occupied in advance and according to a predetermined back-off counter value (S332), the signal for occupying the unlicensed band resource (or preamble). The transmission possible point of time (subframe) is checked (S332).

Thereafter, the NB may check or calculate a data processing time for an unlicensed band resource occupying signal in consideration of a transmittable time point (subframe), and confirm or calculate a signal length (number of OFDM symbols) that can be transmitted in a corresponding subframe period. (S333).

Accordingly, within the identified range, the NB determines the transmission time (subframe) and the length of the signal of the final unlicensed band resource occupancy signal (S334), and performs back-off with the CCA searching for the optimal channel. In operation S335, when the back-off counter value decreases to 0 and another WLAN system does not occupy the unlicensed band (S336), the signal (or preamble) for occupying the corresponding unlicensed band resource at the transmission time point (subframe) is performed. Subframe data including the transmission is transmitted to the UE through the unlicensed band (S337).

On the other hand, when the scheduling scheme is Cross Carrier Scheduling (S330), when the NB refers to the generation of the Explicit PDCCH (including the actual amount of resources used) in the licensed band cell (340), first, whether the NB can occupy the unlicensed band in advance Carrier sensing is performed and the transmission time point (subframe) of the unlicensed band resource occupancy signal (or preamble) is checked according to a predetermined back-off counter value (S350).

Thereafter, the NB checks or calculates a data processing time for an unlicensed band resource occupancy signal in consideration of a transmittable time point (subframe), and checks or calculates a signal length (number of OFDM symbols) that can be transmitted in a corresponding subframe period. Subframe data including the corresponding unlicensed band resource occupancy signal (or preamble) is generated (S352). In this case, data may be loaded in a fixed slot usage method of the unlicensed band, that is, the entire slot of the subframe, and may be generated so that the data is loaded only in the second slot which is the rear part of the subframe.

When the corresponding subframe data is generated (S352) and the unlicensed band is used, the NB performs back-off with CCA searching for an optimal channel (S353), and the back-off counter value is reduced to 0, and another WLAN system If the unlicensed band is not occupied (S354), the subframe data including the unlicensed band resource occupancy signal (or preamble) is transmitted to the UE through the unlicensed band at the transmission time (subframe) (S355). ).

At the same time, when the corresponding subframe data is generated (S352) and the licensed band is used, the corresponding subframe data is transmitted when the subframe data including the unlicensed band resource occupancy signal (or preamble) is transmitted through the unlicensed band. It is possible to transmit to the UE through the licensed band (S356).

In addition, when the Explicit PDCCH (including the actual amount of resources used) does not occur in the licensed band cell and thus the NB cannot refer to the Explicit PDCCH (S340), first, the NB performs carrier sensing on whether the unlicensed band can be occupied in advance. In operation S360, the transmission time point (subframe) of the unlicensed band resource occupancy signal (or preamble) is checked according to a predetermined back-off counter value (S361).

Thereafter, the NB checks or calculates a data processing time for an unlicensed band resource occupancy signal in consideration of a transmittable time point (subframe), and checks or calculates a signal length (number of OFDM symbols) that can be transmitted in a corresponding subframe period. Subframe data including the corresponding unlicensed band resource occupancy signal (or preamble) is generated (S352). In this case, an unlicensed band selection method of the unlicensed band, that is, the data may be loaded in the entire slot of the subframe, and in this case, the data may be generated only in the second slot that is later in the subframe, or arbitrarily slot without slot allocation. The selected and used subframe data may be generated.

When the corresponding subframe data is generated (S362) and the unlicensed band is used, the NB performs back-off with the CCA searching for the optimal channel (S363), and the back-off counter value is reduced to 0, and another WLAN system If the unlicensed band is not occupied (S364), the subframe data including the unlicensed band resource occupancy signal (or preamble) is transmitted to the UE through the unlicensed band at the transmission time (subframe) (S365). ).

At the same time, when the corresponding subframe data is generated above (S362) and the licensed band is used, the subframe data including the unlicensed band resource occupancy signal (or preamble) is transmitted through the unlicensed band according to channel conditions. Subframe data may be transmitted to the UE through the licensed band (S366).

FIG. 26 illustrates a downlink data reception order of a UE in a frequency shared wireless communication system according to an embodiment of the present invention.

Referring to FIG. 24, first, upon receiving an unlicensed band cell activation request (see S320) from an NB, the UE transmits a corresponding response (S410).

If it is determined that the scheduling scheme is not Cross Carrier Scheduling (S420), the UE receives the unlicensed band downlink signal from the NB (S421), and the subframe data including the unlicensed band resource occupancy signal (or preamble) (see S337). Is detected (S422). Based on this, the UE may receive and demodulate downlink data from the NB (S423).

On the other hand, when the scheduling scheme is Cross Carrier Scheduling (S420), when the UE refers to the Explicit PDCCH from the NB (S430), during the unlicensed band cell activation period, the UE receives a downlink signal from the NB (S440). The unlicensed band resource occupancy signal (or preamble) S355 / S356, which is Cross Carrier Scheduling information in NB, may be extracted and received and demodulated based on the unlicensed band downlink data (S441).

In addition, when the UE does not reference the Explicit PDCCH from the NB (S430), during the unlicensed band cell activation period, the UE receives a downlink signal from the NB (S450) and the unlicensed band resource which is Cross Carrier Scheduling information in the NB. The occupied signal (or preamble) S365 / S366 is extracted and the unlicensed band downlink signal is received based on this (S451). However, except for the period in which there is no downlink signal in the downlink subframe (S452), the unlicensed band downlink data may be received and demodulated according to the cross carrier scheduling information (S453).

As described above, in the frequency shared wireless communication system 100 according to the present invention, WiFi, etc., may be configured by a preamble configuration and transmission method of an unlicensed band frame structure and a physical random access channel (PRACH) channel using the special subframe. It can occupy unlicensed band resources without collision or interference with unlicensed band systems. In addition, according to the signal transmission method of the present invention for occupying a channel in a GP (Guard Period) section, an uplink- allocated terminal does not allow an unlicensed band system to occupy a channel first. It is possible to reliably occupy this unlicensed band channel. In addition, the system is classified into Cross Carrier Scheduling using a licensed band and Self Scheduling using a downlink of an unlicensed band. The frequency coexistence wireless communication system of the present invention can stably occupy non-contiguous unlicensed band resources.

The above description is merely illustrative of the technical idea of the present invention, and those skilled in the art to which the present invention pertains may make various modifications and changes without departing from the essential characteristics of the present invention.

Therefore, the embodiments disclosed in the present invention are not intended to limit the technical idea of the present invention but to describe the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The protection scope of the present invention should be interpreted by the following claims, and all technical ideas within the equivalent scope should be interpreted as being included in the scope of the present invention.

Claims (20)

In the channel occupancy method for using the unlicensed band as a secondary in the wireless communication system using the licensed band, Downlink pilot time slot (DwPTS), variable length guard period (GP), and UL signal for DL signal transmission between downlink (DL) and uplink (UL) subframes for channel occupancy of the unlicensed band Using a Special Subframe consisting of an UpPTS (Uplink Pilot Time Slot) section for transmission, The base station transmits a signal to the user terminal in the DwPTS section by not transmitting a signal (No-Tx) or by using a section for one or more of control signal transmission, data transmission, carrier sensing, and back-off. Doing; And Transmitting, by the user terminal, a physical random access channel (PRACH) preamble for UL synchronization in a continuous period of the period of the No-Tx, the GP period, and the UpPTS period; Channel occupancy method comprising a. The method of claim 1, And the user terminal can stop transmission of the PRACH preamble at a symbol or subframe boundary. The method of claim 1, In the step of transmitting the PRACH preamble, when the DwPTS interval is No-Tx, one or more user terminals transmit the PRACH preamble from before the GP interval, characterized in that it comprises. The method of claim 1, And in the step of transmitting the PRACH preamble, the user terminal transmits the PRACH preamble only in the GP section or the UpPTS section. The method of claim 1, And in the step of transmitting the preamble, the user terminal transmits the PRACH preamble using a part of the unlicensed band or the entire unlicensed band. The method of claim 1, In the step of transmitting the preamble, the user terminal, in order to occupy the channel of the unlicensed band, the No-Tx section or the rest period by the GP is occupied by the unlicensed band system after the end of the signal transmission of the DwPTS. The PRACH preamble or the UL subframe is transmitted after leaving a fixed offset of a predetermined length or less within the GP period from the end time. The method of claim 1, And the user terminal transmits the PRACH preamble to a corresponding channel of the unlicensed band according to the index information from the base station that has scheduled the unlicensed band uplink resource. The method of claim 1, When the base station informs the PRACH channel allocation information of the unlicensed band including the index information using a predetermined message or a PDCCH signal, the user terminal corresponds to the unlicensed band channel corresponding to the subframe index of the allocated unlicensed band. Channel occupancy method for transmitting the PRACH preamble. The method of claim 8, And the base station transmits the message or the PDCCH signal in a licensed or unlicensed band. The method of claim 8, The base station further informs the bit information indicating whether the number of consecutive UL subframes after the UpPTS through the PRACH channel allocation information, the user terminal is assigned to the first UL subframe after the UpPTS In the case, the channel occupancy method, characterized in that for transmitting the PRACH preamble in a continuous period of the interval of the No-Tx, the GP interval and the UpPTS interval. The method of claim 8, And if the user terminal does not occupy the corresponding unlicensed band channel in the subframe index of the allocated unlicensed band, the user terminal accesses and occupies the corresponding unlicensed band channel within a UL window section of a predetermined length. In the channel occupancy method for using the unlicensed band as a secondary in the wireless communication system using the licensed band, Between downlink (DL) and uplink (UL) subframes, a downlink pilot time slot (DwPTS) for DL signal transmission, a guard period (GP) that is variable in length, and an uplink pilot time for UL signal transmission Slot) using a special subframe consisting of a section, in order to occupy the uplink channel of the unlicensed band, Determining, at the base station, either scheme of Self Scheduling or Cross Carrier Scheduling; Transmitting, by the base station in self scheduling, information on an unlicensed band UL channel allocated to the user terminal to the user terminal in a special subframe in an unlicensed band; And The base station in the cross carrier scheduling, attempting to access the user terminal in an unlicensed band within a predetermined UL window period and receiving uplink data Channel occupancy method comprising a. The method of claim 12, When the base station occupies the UL channel in advance in Cross Carrier Scheduling, the DwPTS signal including information about the unlicensed band UL channel within the UL window period is transmitted based on the transmission from the licensed band to the user terminal. Channel occupancy method characterized in that for receiving uplink data. The method of claim 12, When the base station does not occupy the UL channel in advance in the cross carrier scheduling, uplink data based on detecting a physical random access channel (PRACH) preamble of an unlicensed band received from the user terminal within the UL window period Channel occupancy method characterized in that for receiving. The method of claim 12, In the Self Scheduling, when the user terminal is allocated to the first UL subframe after the UpPTS, transmitting the PRACH Preamble in a continuous period of the No-Tx interval, the GP interval, and the UpPTS interval. Channel occupancy method characterized by. The method of claim 12, In the Cross Carrier Scheduling, when the user terminal previously occupies the UL channel notified from the base station, the PRACH preamble is transmitted to the special subframe in the special subframe within the UL window period notified from the base station. And occupying the uplink data to the base station. The method of claim 12, In the Cross Carrier Scheduling, when the user terminal does not previously occupy the UL channel notified from the base station, the DwPTS signal is received from the base station within the UL window period notified from the base station, and the PRACH Preamble And transmitting the uplink data to the base station based on the transmission to the base station. In the channel occupancy method for using the unlicensed band as a secondary in the wireless communication system using the licensed band, Between downlink (DL) and uplink (UL) subframes, a downlink pilot time slot (DwPTS) for DL signal transmission, a guard period (GP) that is variable in length, and an uplink pilot time for UL signal transmission Slot) using a special subframe consisting of a section, in order to occupy the downlink channel of the unlicensed band, Determining, at the base station, either scheme of Self Scheduling or Cross Carrier Scheduling; Transmitting, by the base station in self scheduling, subframe data, including a signal for occupying an unlicensed band resource, to a user terminal through an unlicensed band at a predetermined transmission time point; And In the Cross Carrier Scheduling, the base station transmits the subframe data generated by the unlicensed band system including the unlicensed band resource occupancy signal to a user terminal through the unlicensed band and the licensed band at a predetermined transmission time point not occupying the corresponding unlicensed band. Steps to Channel occupancy method comprising a. The method of claim 18, In the Cross Carrier Scheduling, after checking the transmittable time, the data is loaded in all slots of the corresponding subframe, or the subframe data is generated so that the data is loaded only in the second slot of the corresponding subframe. How to occupy your channel. The method of claim 18, The user terminal receives and demodulates unlicensed band downlink data based on the unlicensed band resource occupancy signal for receiving and detecting an unlicensed band downlink signal from the base station during an unlicensed band activation period. Way.

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