KR102268262B1 - Frame structure for licensed assisted access in wireless communication system, method and apparatus using the frame structure - Google Patents

Abstract

Provided are a frame structure for Licensed Assisted Access (LAA) in a wireless communication system, a method for using the same, and an apparatus. In a wireless communication system supporting carrier aggregation between a serving cell of a licensed band and a serving cell of an unlicensed band, the communication method of the base station is a radio frame with a ratio between uplink and downlink and determining an uplink-downlink configuration to be applied to the serving cell of the unlicensed band based on at least one of the number of changes, and transmitting information on the determined uplink-downlink configuration to the terminal and performing uplink reception and downlink transmission according to the uplink-downlink configuration.

Description

FRAME STRUCTURE FOR LICENSED ASSISTED ACCESS IN WIRELESS COMMUNICATION SYSTEM, METHOD AND APPARATUS USING THE FRAME STRUCTURE

The present invention relates to a frame structure for LAA in a wireless communication system supporting Licensed Assisted Access (LAA), a method for using the same, and an apparatus.

Cellular is a concept proposed to overcome the limitations of the service area, frequency and subscriber capacity, and divides the mobile communication service area into several small cell units so that frequencies can be spatially reused. . However, in a specific area such as a hotspot inside a cell, a particularly high communication demand occurs, and the reception sensitivity of radio waves may decrease in a specific area such as a cell edge or a coverage hole. Accordingly, for the purpose of enabling communication in a hotspot, a cell boundary, a coverage hole, etc., in a macro cell, small cells, for example, a pico cell, a femto cell, etc. , a micro cell, a remote radio head (RRH), a relay, a repeater, etc. are installed together. Such a network is called a heterogeneous network. In a heterogeneous network environment, a macro cell is a cell having a relatively large coverage, and a small cell such as a femto cell and a pico cell is a cell having a small coverage.

However, with the rapid increase in wireless communication traffic, despite the active use of the small cell as described above, securing more frequencies is still an urgent issue. Accordingly, a method of performing wireless communication using frequencies of not only a licensed band but also an unlicensed band such as a WiFi band based on carrier aggregation (CA) is being discussed. CA is a technology for efficiently using fragmented small bands. In the frequency domain, physically continuous or non-continuous bands are bundled together to achieve the same effect as using a logically large band. it is to do

However, in the case of the unlicensed band, competitive access is allowed in order to avoid a case in which wireless communication devices transmit simultaneously on the same channel. Therefore, a wireless communication device that intends to use the unlicensed band must acquire a channel access opportunity before using the corresponding channel. Therefore, the radio resources of the unlicensed band cannot be continuously occupied. Therefore, when carrier aggregation is configured between the serving cell of the licensed band and the serving cell of the unlicensed band, a new frame structure for non-continuous transmission on the unlicensed band is required.

An object of the present invention is to provide a frame structure capable of efficiently configuring uplink resources and downlink resources when carrier aggregation is configured between a serving cell of a licensed band and a serving cell of an unlicensed band, and a method and apparatus using the same.

According to an aspect of the present invention, a communication method of a base station in a wireless communication system supporting carrier aggregation between a serving cell of a licensed band and a serving cell of an unlicensed band is a radio frame (radio frame) Determining an uplink-downlink configuration to be applied to a serving cell of the unlicensed band based on at least one of the number of changes and the proportion between the uplink and the downlink in the determined uplink-downlink It may include transmitting configuration information to the terminal and performing uplink reception and downlink transmission according to the uplink-downlink configuration.

According to another aspect of the present invention, a communication method of a terminal in a wireless communication system supporting carrier aggregation between a serving cell of a licensed band and a serving cell of an unlicensed band includes at least one of the proportion and number of changes between uplink and downlink in a radio frame. Receiving information on an uplink-downlink configuration determined based on , and performing uplink transmission and downlink reception based on information on the determined uplink-downlink configuration. may include

According to another aspect of the present invention, a wireless communication device supporting carrier aggregation between a serving cell of a licensed band and a serving cell of an unlicensed band is based on at least one of the ratio and number of changes between the uplink and the downlink in the radio frame. A processor that determines an uplink-downlink configuration to be applied to a serving cell of the unlicensed band, and checks whether transmission is possible through a serving cell of the unlicensed band according to the determined uplink-downlink configuration, and a serving cell of the unlicensed band When transmission is possible through , it may include a radio frequency (RF) unit that performs at least one of uplink reception and downlink transmission according to the uplink-downlink configuration.

According to another aspect of the present invention, a wireless communication device supporting carrier aggregation between a serving cell of a licensed band and a serving cell of an unlicensed band is determined based on at least one of the ratio between uplink and downlink in a radio frame and the number of changes. It may include an RF unit for receiving information on the uplink-downlink configuration and a processor for performing uplink transmission and downlink reception based on the determined information on the uplink-downlink configuration.

Even when carrier aggregation is configured between the serving cell of the licensed band and the serving cell of the unlicensed band, the base station and the terminal can configure uplink resources and downlink resources more efficiently.

1 shows a wireless communication system to which the present invention is applied.
2 shows examples of an LAA deployment scenario to which the present invention is applied.
3 is a diagram illustrating a frame structure for using an unlicensed band.
4 is a diagram illustrating a frame structure of a wireless communication system to which the present invention is applied.
5 is a view showing a frame structure for LAA according to the first embodiment of the present invention.
6 is a diagram illustrating a frame structure for LAA according to a second embodiment of the present invention.
7 is a diagram illustrating a frame structure for LAA according to a third embodiment of the present invention.
8 is a diagram illustrating a frame structure for LAA according to a fourth embodiment of the present invention.
9 is a diagram illustrating a frame structure for LAA according to a fifth embodiment of the present invention.
10 is a diagram illustrating a frame structure for LAA according to a sixth embodiment of the present invention.
11 is a flowchart illustrating an operation of a base station according to the present invention.
12 is a flowchart illustrating an operation of a terminal according to the present invention.
13 is a block diagram illustrating a wireless communication system according to an embodiment of the present invention.

Hereinafter, some embodiments will be described in detail with reference to exemplary drawings. In adding reference numerals to the components of each drawing, it should be noted that the same components are given the same reference numerals as much as possible even though they are indicated on different drawings. In addition, in describing the embodiments of the present specification, if it is determined that a detailed description of a related known configuration or function may obscure the gist of the present specification, the detailed description thereof will be omitted.

In addition, this specification describes a wireless communication network, and the work performed in the wireless communication network is performed in the process of controlling the network and transmitting data in a system (eg, a base station) having jurisdiction over the wireless communication network, or the corresponding wireless communication network. The operation may be performed in a terminal connected to the network.

1 shows a wireless communication system to which the present invention is applied.

The network structure shown in FIG. 1 may be that of an Evolved-Universal Mobile Telecommunications System (E-UMTS). The E-UMTS system may include a Long Term Evolution (LTE), an advanced LTE (LTE-A) system, and the like. Wireless communication systems are widely deployed to provide various communication services such as voice, packet data, and the like.

On the other hand, there is no limitation on the multiple access technique applied to the wireless communication system. Code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), Orthogonal Frequency Division Multiple Access (OFDMA), Single Carrier-FDMA (SC-FDMA), OFDM-FDMA, OFDM-TDMA , various multiple access schemes such as OFDM-CDMA can be used.

Referring to FIG. 1 , the E-UTRAN includes at least one base station (BS) 20 that provides a control plane and a user plane to a terminal. The terminal 10 (User Equipment, UE) may be fixed or have mobility, and may be a mobile station (MS), an advanced MS (AMS), a user terminal (UT), a subscriber station (SS), a wireless device, etc. term can be called.

The base station 20 generally refers to a station communicating with the terminal 10, and an evolved-NodeB (eNB), a base transceiver system (BTS), an access point, and a femto-eNB. ), a pico base station (pico-eNB), a home base station (Home eNB), may be referred to as other terms such as relay (relay). The base station 20 may provide at least one cell to the terminal. A cell may mean a geographic area in which the base station 20 provides a communication service, or may mean a specific frequency band. A cell may mean a downlink frequency resource and an uplink frequency resource. Alternatively, the cell may mean a combination of a downlink frequency resource and an optional uplink frequency resource. In addition, in general, when carrier aggregation (CA) is not considered, uplink and downlink frequency resources are always present as a pair in one cell.

An interface for transmitting user traffic or control traffic may be used between the base stations 20 . The source base station (Source BS, 21) means a base station in which a radio bearer is currently established with the terminal 10, and the target base station (Target BS, 22) is a new terminal after the terminal 10 disconnects the radio bearer with the source base station 21. It means a base station to handover to establish a radio bearer. The base stations 20 may be connected to each other through an X2 interface. The X2 interface is used to send and receive messages between the base stations 20 . In addition, the base station 20 is connected to an Evolved Packet System (EPS), more specifically, a Mobility Management Entity (MME)/Serving-Gateway (S-GW) 30 through the S1 interface. The S1 interface supports a many-to-many-relation between the base station 20 and the MME/S-GW 30 . PDN-GW (Packet Date Network-Gateway, 40) is used to provide a packet data service to the MME/S-GW 30 .

Hereinafter, downlink means communication from the base station 20 to the terminal 10 , and uplink means communication from the terminal 10 to the base station 20 . The downlink is also called a forward link, and the uplink is also called a reverse link. In the downlink, the transmitter may be a part of the base station 20 , and the receiver may be a part of the terminal 10 . In the uplink, the transmitter may be a part of the terminal 10 , and the receiver may be a part of the base station 20 . In a wireless communication system, a Time Division Duplex (TDD) method transmitted using different times may be used as uplink transmission and a downlink transmission method, or a Frequency Division Duplex (FDD) method transmitted using different frequencies may be used. can be used

Meanwhile, carrier aggregation (CA) supports a plurality of carriers and is also referred to as spectrum aggregation or bandwidth aggregation. An individual unit carrier bundled by carrier aggregation is called a component carrier (CC). Each component carrier is defined by its bandwidth and center frequency. For example, if five component carriers are allocated as a granularity of a carrier unit having a bandwidth of 20 MHz, a bandwidth of up to 100 MHz may be supported.

Hereinafter, a multiple carrier system includes a system supporting carrier aggregation (CA). A serving cell may be defined as a component frequency band that may be aggregated by CA based on a multiple component carrier system. The serving cell includes a primary serving cell (PCell) and a secondary serving cell (SCell). The primary serving cell provides a security input and Non-Access Stratum (NAS) mobility information in a Radio Resource Control (RRC) connection (establishment) or re-establishment state. It means a serving cell. According to the capabilities of the terminal, at least one cell may be configured to form a set of serving cells together with a primary serving cell. The at least one cell is referred to as a secondary serving cell. A set of serving cells configured for one UE may be configured with only one primary serving cell, or may include one primary serving cell and at least one secondary serving cell. Each serving cell may be operated in an activated or deactivated state.

2 shows examples of an LAA deployment scenario to which the present invention is applied.

It is difficult to meet the increasing demand for data services by simply dividing cells into macro cells and micro cells. Accordingly, small cells such as a pico cell, a femto cell, and a wireless relay may be used for a data service. In general, the small cell is advantageous compared to the macro cell in terms of throughput that can be provided to a single terminal because it serves a smaller area compared to the macro cell. However, as wireless communication traffic rapidly increases, securing more frequencies in order to improve throughput is emerging as an urgent problem. Accordingly, a method for performing wireless communication using frequencies of not only a licensed band but also an unlicensed band such as a WiFi band is being discussed. In order to smoothly support wireless communication in the unlicensed band, wireless communication in the unlicensed band may be provided under the support of the communication technique of the licensed band.

Hereinafter referred to as License Assisted Access (LAA), the CA operation for one or more secondary serving cells operating in the unlicensed band or unlicensed spectrum is supported based on the assistance of the primary serving cell operating in the licensed band or spectrum. represents a wireless communication technique. In other words, LAA is a technology that binds the licensed band and the unlicensed band together using the CA using the LTE licensed band as an anchor. In this case, one of the serving cells in the licensed band may be used as the primary serving cell, and the serving cells in the unlicensed band may always be configured as secondary serving cells. In addition, the unlicensed band is activated only through CA and may not perform LTE communication alone. The terminal accesses the network with the licensed band to use the service, and the base station combines the licensed band and the unlicensed band with CA depending on the situation to offload traffic of the licensed band to the unlicensed band.

2 illustrates, as an example, various LAA deployment scenarios. In each scenario, the number of licensed carriers and unlicensed carriers may each be one or more. As an example, scenario 1 is a case in which a macro cell using a licensed carrier F1 (frequency 1) and a small cell using an unlicensed carrier F3 are connected by carrier aggregation (CA). In this case, the macro cell and the small cell may be non-co-located and may be connected to each other through an ideal backhual.

As another example, scenario 2 is a case in which a small cell #1 using a licensed carrier F2 and a small cell #2 using an unlicensed carrier F3 without macro cell coverage are connected by carrier aggregation. In this case, the small cell #1 and the small cell #2 may be co-located with each other and may be connected to each other through an ideal backhaul.

As another example, scenario 3 is a case in which there are a macro cell and a small cell #1 using a licensed carrier F1, and the small cell #1 and a small cell #2 using an unlicensed carrier F3 are connected by carrier aggregation. In this case, the macro cell and the small cell #1 may be connected to each other through an ideal or non-ideal backhaul, and the small cell #1 and the small cell #2 may be connected to each other through an ideal backhaul and co-located with each other. may be co-located.

As another example, scenario 4 includes a macro cell using a licensed carrier F1, a small cell #1 using a licensed carrier F2, and a small cell #2 using an unlicensed carrier F3, a small cell #1 and a small cell. This is the case where #2 is connected by carrier aggregation. In this case, the macro cell and the small cell #1 may be connected to each other by an ideal or non-ideal backhaul, and the small cell #1 and the small cell #2 may be connected to each other by an ideal backhaul and co-located with each other. may be co-located. If the macro cell and the small cell #1 are connected to each other through an ideal backhaul, the macro cell F1, the small cell #1 (F2), and the small cell #2 (F3) may be connected by carrier aggregation. .

3 is a diagram illustrating a frame structure for using an unlicensed band.

In order to use the unlicensed band, it is necessary to follow the following regulations. Individual regulations may or may not exist by country/region. Alternatively, each country/region may have a standard of a different value.

The nominal channel bandwidth of the unlicensed band is 5 MHz or more, and about 80% to 100% of the nominal channel bandwidth should be used as the occupied channel bandwidth for actual transmission. Therefore, for the efficiency of the overall wireless communication system, a 20 MHz bandwidth may be used in a wireless communication system supporting LAA.

On the other hand, the unlicensed band permits a process in which a base station or a terminal acquires a channel access opportunity based on contention. There may be several contention-based channel access methods. A channel access mechanism for an unlicensed band according to the present invention includes the following.

A contention-based channel access mechanism for unlicensed bands provides opportunistic channel access. To this end, a wireless communication device such as a base station performs Clear Channel Assessment (CCA) or Extended Clear Channel Assessment (ECCA) before using a corresponding channel. This is to avoid transmission that occurs concurrently on the same channel with other RLAN (Radio Local Area Network) systems. Here, CCA or ECCA determines whether the corresponding channel is in the channel interference, occupied or unoccupied state, that is, whether the corresponding channel is busy or idle through energy scan or detection for the corresponding channel. It is a process of judgment Such contention-based channel access mechanism may be called LBT (Listen Before Talk) or carrier sensing (CS: Carrier Sensing).

Under the LBT protocol, the wireless communication device determines whether a corresponding channel is available for transmission based on energy measured in the corresponding channel. LBT may be performed on a frame-based or load-based basis.

In the case of frame-based LBT, parameters such as CCA, extended CCA, channel occupancy time, idle time, and CCA energy detection threshold are required to satisfy the LBT requirements. can be defined.

Referring to Figure 3, the frame structure for the frame-based LBT may be expressed as a fixed frame period (fixed frame period) defined by the channel use time, the idle time, and CCA. Here, the channel use time may be 1 ms to 10 ms, and the CCA may be greater than 20 us. The idle time and the length of time in the frame structure for the CCA should be at least 5% greater than the channel usage time. Accordingly, the wireless communication device using the unlicensed band may occupy the corresponding channel by performing (E) CCA at the end of the idle time.

On the other hand, in the case of the load-based LBT, unlike the frame-based LBT, the channel occupancy can be evaluated by performing a predetermined CCA operation at any time without using a specific frame structure. In this case, if the channel is not occupied during the randomly selected N CCAs, the corresponding wireless communication device may occupy the channel.

Meanwhile, in order to control interference between wireless communication devices within the unlicensed band, the wireless communication devices using the unlicensed band must perform power control of at least a certain level (eg, at least 3 dB). In a wireless communication system supporting LAA, the regulation may be satisfied through transmit power control.

In addition, when using an unlicensed band, a Dynamic Frequency Selection (DFS) operation should be considered. The purpose of DFS is to avoid interference with radar systems and to achieve a near-uniform load in a band such as 5 GHz. When a relatively slow time scale such as seconds is considered in the DFS procedure, the DFS requirements can be expressed as shown in Table 1 below.

parameters requirement DFS threshold Region Specific Channel availability check > 60 seconds Channel move time < 10 seconds non-occupancy time > 30 minutes

Since all DFS requirements as shown in Table 1 are based on long period values, in a wireless communication system supporting LAA, the corresponding request is made through higher layer signaling (eg, serving cell deactivation or deconfiguration). things can be satisfied.

On the other hand, since there are many carriers in the unlicensed band and they are used by various wireless communication devices, a method for appropriately selecting unused carriers is needed in order to reduce interference between transmitters and to ensure fair use between transmitters.

Due to such regulations, in the case of an unlicensed band, unlike a licensed band, it is difficult to continuously occupy radio resources. Accordingly, in the present specification, when carrier aggregation is configured between the serving cell of the licensed band and the serving cell of the unlicensed band, new frame structures are provided for non-continuous transmission on the unlicensed band by the following method.

4 is a diagram illustrating a frame structure of a wireless communication system to which the present invention is applied.

4 shows a frame structure of FDD and a frame structure of TDD as an example. One radio frame (radio frame) includes 10 subframes (subframe), one subframe includes two consecutive (consecutive) slots (slot).

In the case of FDD, a carrier used for uplink transmission and a carrier used for downlink transmission exist, respectively, and uplink transmission and downlink transmission may be simultaneously performed within one cell.

On the other hand, in the case of TDD, uplink transmission and downlink transmission are temporally separated based on one cell. Since the same carrier is used for uplink transmission and downlink transmission, the base station and the terminal repeatedly switch between the transmission mode and the reception mode. In addition, in the case of TDD, a special subframe may be provided to provide a guard period for mode switching between transmission and reception.

As shown in FIG. 4, the special subframe may include a downlink part (DwPTS: Downlink Pilot Time Slot), a guard period (GP: Guard Period), and an uplink part (UpPTS: Uplink Pilot Time Slot). DwPTS is used for initial cell search, synchronization, or channel estimation in the UE. UpPTS is used to synchronize the channel estimation in the base station with the uplink transmission synchronization of the terminal. GP is necessary to avoid interference between uplink and downlink, and neither uplink transmission nor downlink transmission is performed during the guard period. Table 2 below shows a special subframe configuration.

Special subframe configuration Normal CP in DL Extended CP in DL DwPTS UpPTS DwPTS UpPTS Generic CP at UL Extended CP in UL Generic CP at UL Extended CP in UL 0 6592 Ts

2192 Ts

2560 Ts 7680 Ts 2192 Ts 2560 Ts One 1960 Ts 20480 Ts 2 21952 Ts 23040 Ts 3 24144 Ts 25600 Ts 4 26336 Ts 7680 Ts 4384 Ts 5120 Ts 5 6592 Ts
4384 Ts
5120 Ts 20480 Ts 6 1960 Ts 23040 Ts 7 21952 Ts 15800 Ts 8 24144 Ts - - - 9 13168 Ts - - -

Referring to Table 2, the configuration of special subframes in the TDD frame is divided into 9 types in a normal cyclic prefix (CP) and 7 types in an extended CP.

Meanwhile, the following Table 3 shows an example of an uplink-downlink configuration of a TDD radio frame (UL-DL configuration).

UL-DL configuration
transition point cycle
subframe number 0 One 2 3 4 5 6 7 8 9 0 5 ms D S U U U D S U U U One 5 ms D S U U D D S U U D 2 5 ms D S U D D D S U D D 3 10 ms D S U U U D D D D D 4 10 ms D S U U D D D D D D 5 10 ms D S U D D D D D D D 6 5 ms D S U U U D S U U D

Referring to Table 3, the UL-DL configuration defines a subframe reserved for uplink transmission and a subframe reserved for downlink transmission. That is, the UL-DL configuration informs by which rule the uplink and downlink are allocated (or reserved) to all subframes in one radio frame. In Table 3, D denotes a downlink subframe, U denotes an uplink subframe, and S denotes a special subframe, respectively.

Referring to Table 3, in each UL-DL configuration, subframes 0 and 5 are always allocated for downlink transmission, and subframe 2 is always allocated for uplink transmission. In addition, the positions and the number of downlink subframes and uplink subframes in one radio frame are different for each UL-DL configuration. In the case of TDD, the amount of resources allocated for uplink and downlink transmission can be asymmetrically given through such various UL-DL configurations. In this case, in order to avoid severe interference between downlink and uplink between cells, in general, neighboring cells may have the same UL-DL configuration.

On the other hand, the time at which the DL is switched to the UL or the time when the UL is switched to the DL is referred to as a switching point. The switch-point periodicity refers to a period in which the UL subframe and the DL subframe are switched identically, and is 5 ms or 10 ms. For example, looking at UL-DL configuration 0 of Table 3, the 0th to 4th subframes are switched to D->S->U->U->U, and the 5th to 9th subframes are the same as before. Likewise, it is converted to D->S->U->U->U. Since one subframe has a length of 1 ms, the periodicity of the transition time is 5 ms. That is, the periodicity of the switching time is less than the length of one radio frame (10 ms), and the switching aspect is repeated within the radio frame.

The UL-DL configuration shown in Table 3 may be transmitted from the base station to the terminal through system information. For example, the base station may notify the terminal of the change in the uplink-downlink allocation state of the radio frame by transmitting only the index of the corresponding UL-DL configuration whenever the UL-DL configuration is changed. Alternatively, the UL-DL configuration may be control information commonly transmitted to all terminals in a cell through a broadcast channel.

On the other hand, in the frame structure for using the unlicensed band as shown in FIG. 3, the idle time according to each channel usage time is summarized in symbol units as shown in Table 4 below.

Channel usage time (ms) One 2 3 4 5 6 7 8 9 10 Minimum idle time with CCA (ms) 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45 0.5 Number of symbols for minimum idle time including CCA One 2 3 3 4 5 5 6 7 7

Table 4 shows a standard CP, and in the case of a normal CP, the symbol length is 0.0719ms (71.9us) for the first symbol in the slot and 0.0713ms (71.3us) for the remaining symbols.

In addition, the special subframe configuration of Table 2 is summarized in symbol units in the general CP structure, as shown in Table 5 below.

Special subframe configuration
(Special subframe configuration) Number of symbols (in case of normal CP for both uplink and downlink) DwPTS GP UpPTS 0 Three 10 things One One 9 pieces 4 2 10 things Three 3 11 pieces 2 4 12 pieces One 5 Three 9 pieces 2 6 9 pieces Three 7 10 things 2 8 11 pieces One

On the other hand, in the frame structure for using the unlicensed band as shown in FIG. 3, the length of the CCA is at least 20us. Accordingly, in a wireless communication system supporting LAA, the uplink subframe may be expressed by the length of uplink symbols and the length of the idle time including the CCA. The idle time including CCA may have a length corresponding to a value obtained by subtracting the Ts value for uplink symbols from 30720·Ts, which is the length of the subframe, and the idle time without CCA is 30720·Ts in the uplink symbol It may have a length corresponding to a value obtained by subtracting the Ts value for the CCA and the Ts value for the CCA. In this case, since the length of the CCA is 20us or more, it may be a value greater than 615.4·Ts (eg, 615·Ts) when expressed as a Ts value. In the case of a general CP structure, Table 6 below summarizes them.

UL subframe configuration for LAA uplink symbol Symbols for idle time with CCA 0 11 pieces
(= 24144 Ts) Three
(= 6576·Ts) One 12 pieces
(= 26336 Ts) 2
(= 4384 Ts) 2 13 pieces
(= 28528·Ts) One
(= 2192·Ts)

Meanwhile, in the case of a general CP structure in the same manner as in Table 6, a downlink subframe in a wireless communication system supporting LAA may be expressed by the length of downlink symbols and the length of the idle time including the CCA as shown in Table 7. have.

DL subframe configuration for LAA downlink symbol Symbols for idle time with CCA 0 11 pieces
(= 24144 Ts) Three
(= 6576·Ts) One 12 pieces
(= 26336 Ts) 2
(= 4384 Ts) 2 13 pieces
(= 28528·Ts) One
(= 2192·Ts)

Accordingly, in a wireless communication system supporting LAA, an uplink subframe may be configured in the following two cases.

1) All symbols in one subframe are used for uplink transmission as uplink symbols

2) As shown in Table 6, one subframe can be expressed by the length of the uplink symbols and the length of the idle time including the CCA. In this case, some uplink symbols included in the one subframe are uplinked. used for transmission

Similarly, in a wireless communication system supporting LAA, a downlink subframe may be configured in the following two cases.

1) All symbols in one subframe are used for downlink transmission as downlink symbols

2) As shown in Table 7, one subframe may be expressed by the length of downlink symbols and the length of the idle time including the CCA. In this case, some downlink symbols included in the one subframe are downlinked. used for transmission

In addition, a subframe having a structure similar to the special subframe described in Tables 2, 3, and 5 may be used in a wireless communication system supporting LAA. In this case, in a subframe having a structure similar to the special server frame, a symbol corresponding to a downlink part (DwPTS) and an uplink part (UpPTS) for downlink transmission and uplink transmission in a wireless communication system supporting LLA, respectively may be used, and a portion corresponding to the guard period (GP) may be used as a symbol for the idle time including the CCA.

Therefore, when uplink transmission and downlink transmission through the unlicensed band are simultaneously supported, the LLA is similar to the UL-DL configuration of Table 3 above based on the weight of UL and DL in the radio frame and the number of conversions between UL and DL. The channel use time for UL and the channel use time for DL in , can be configured in various ways.

For example, when DL is configured M times and UL is configured N times in units of one radio frame, that is, in units of 10 ms (here, M and N are natural numbers), the channel usage times for DL and UL are configured within 4 ms, respectively. can be This is because, in certain countries, the channel usage time may be stipulated within 4ms. In this case, when M is greater than 2, that is, when DLs are configured two or more times in one radio frame, the structures of the fixed frame period for each DL may be the same or different from each other. Similarly, when N is greater than 2, the structures of the fixed frame period for the UL may be the same or different from each other.

If DL No. 2 (ie, M=2) and UL No. 1 (ie, N=1) are configured in one radio frame (10 ms) unit, the channel usage time for DL and UL must be within 4 ms, respectively. One radio frame consists of (DL about 4ms, UL about 2ms, and DL about 4ms), (DL about 4ms, UL about 3ms, and DL about 3ms) and (DL about 3ms, UL about 4ms and DL about 3 ms).

In addition, if one radio frame (10ms) is composed of DL No. 2 (ie, M=2) and UL No. 2 (ie, N=2), the channel usage time for DL and UL should be within 4 ms, respectively. When one radio frame consists of (DL about 1ms, UL about 4ms, DL about 1ms, and UL about 4ms), (DL about 2ms, UL about 3ms, DL about 2ms, and UL about 3ms), ( DL about 3ms, UL about 2ms, DL about 3ms, and UL about 2ms) and (DL about 4ms, UL about 1ms, DL about 4ms, and UL about 1ms) exist.

Therefore, the wireless communication system supporting LAA sets one or more of the following configurations that can use the UL-DL configuration as shown in Table 3 to the UL-DL configuration for LAA, and through higher layer signaling such as RRC signal. A preselected UL-DL configuration for LAA may be used.

- UL-DL configuration for LAA in which one radio frame consists of (DL about 4ms, UL about 2ms, and DL about 4ms). This may be configured based on UL-DL configuration 4 among the UL-DL configurations of Table 3. This means that in the case of UL-DL configuration 4, one radio frame consists of 7 DL subframes (7ms), one special subframe and two UL subframes (2ms), and the special subframe mainly consists of DL symbols. because it becomes This will be described in more detail with reference to FIG. 5 .

- UL-DL configuration for LAA in which one radio frame consists of (DL about 4ms, UL about 3ms, and DL about 3ms). This may be configured based on UL-DL configuration 3 among the UL-DL configurations of Table 3. This is because, in the case of UL-DL configuration 3, one radio frame consists of six DL subframes (6ms), one special subframe, and three UL subframes (3ms). This will be described in more detail with reference to FIG. 6 .

- UL-DL configuration for LAA in which one radio frame consists of DL (about 3ms, UL about 4ms, and DL about 3ms). This will be described in more detail with reference to FIG. 7 .

- UL-DL configuration for LAA in which one radio frame consists of (DL about 2ms, UL about 3ms, DL about 2ms, and UL about 3ms). This may be configured based on UL-DL configuration 0 among the UL-DL configurations of Table 3. This is because, in the case of UL-DL configuration 0, one radio frame consists of one DL subframe (1 ms), one special subframe, and repetition of three UL subframes (3 ms). This will be described in more detail with reference to FIG. 8 .

- UL-DL configuration for LAA in which one radio frame consists of (DL about 3ms, UL about 2ms, DL about 3ms, and UL about 2ms). This may be configured based on UL-DL configuration 1 among the UL-DL configurations of Table 3. This is because, in the case of UL-DL configuration 1, one radio frame consists of two DL subframes (2ms), one special subframe, and repetition of two UL subframes (2ms). This will be described in more detail with reference to FIG. 9 .

- UL-DL configuration for LAA in which one radio frame consists of (DL about 4ms, UL about 1ms, DL about 4ms, and UL about 1ms). This may be configured based on UL-DL configuration 2 among the UL-DL configurations of Table 3. This is because, in the case of UL-DL configuration 2, one radio frame consists of three DL subframes (3ms), one special subframe and one UL subframe (1ms) repetition. This will be described in more detail with reference to FIG. 10 .

Meanwhile, the UL-DL configuration for LAA may be configured as follows.

In configuring the UL-DL configuration for LAA based on the UL-DL configuration for TDD as shown in Table 3, when a structure of a fixed frame period for DL is a structure including a special subframe of a TDD radio frame, TDD UL - According to the DL configuration and the special subframe configuration, a DL subframe and DwPTS within one DL-UL switching time may be applied as a channel usage time in a fixed frame period for DL. For example, in the case of a UL-DL configuration for LAA in which one radio frame (10 ms) includes DL No. 2 and UL No. 1, a fixed frame period for DL No. 1 among the structures of a fixed frame period for DL No. 2 A frame period corresponds to this, and in the case of a UL-DL configuration for LAA in which one radio frame (10 ms) includes DL 2 and UL 2, all structures of a fixed frame period for DL 2 correspond to this. . In this case, the number of symbols for the idle time including the CCA in the structure of each fixed frame period may be determined according to the length of the channel use time based on Table 4. For example, in the case of a UL-DL configuration for LAA in which one radio frame consists of (DL about 2ms, UL about 3ms, DL about 2ms, and UL about 3ms), according to Table 4, two symbols are fixed for DL. It may be determined as the number of symbols for the minimum idle time including the CCA in the specified frame period.

In addition, in configuring the UL-DL configuration for LAA based on the TDD UL-DL configuration as shown in Table 3, when the structure of the fixed frame period for DL is a structure including a special subframe of the TDD radio frame, the GP A special subframe structure having the same number of symbols for idle time including CCA and the same number of symbols for idle time may be used, and a portion corresponding to GP in the special subframe may be applied as idle time including CCA. For example, in the case of a UL-DL configuration for LAA in which one radio frame is composed of (DL about 2ms, UL about 3ms, DL about 2ms, and UL about 3ms), two symbols include a CCA minimum idle time. is a symbol for Therefore, one of the special subframe configurations 3 or 7 in Table 5 may be applied.

Meanwhile, in configuring the UL-DL configuration for LAA based on the UL-DL configuration for TDD as shown in Table 3, when the structure of the fixed frame period for DL is a structure that does not include a special subframe of the TDD radio frame , the structure and length of the channel usage time for DL may be the same as the structure including the special subframe. Accordingly, in the case of the last DL subframe among DL subframes, only some of the symbols in the last DL subframe may be used as the channel usage time. In this case, the structure and length of the idle time including the CCA may also be configured the same as the structure including the special subframe. Accordingly, in the case of the last DL subframe among DL subframes, some of the symbols in the last DL subframe may be used as idle times including the CCA. In this case, if the last one or two symbols are used as UpPTS in a structure including a special subframe, the last one or two symbols may not be used for DL. That is, the last one or two symbols may be unused symbols.

On the other hand, in configuring the UL-DL configuration for LAA based on the UL-DL configuration for TDD as shown in Table 3, the structure of the fixed frame period for DL does not include a special subframe of the TDD radio frame. In the case of the structure, as shown in Table 7, some symbols of the last DL subframe may be used as symbols for the idle time including the CCA. For example, if the number of symbols corresponding to the idle time including CCA is determined to be K (here, K is a natural number), K symbols from the end of the last DL subframe among DL subframes include CCA. It can be used as a symbol for the idle time.

On the other hand, in configuring the UL-DL configuration for LAA based on the UL-DL configuration for TDD as shown in Table 3, the symbol for the idle time including the CCA in the structure of the fixed frame period for UL is each fixed frame. In the structure of the period, it may be determined based on Table 4 according to the length of the channel use time. If the number of symbols corresponding to the idle time including the CCA is determined to be K, as shown in Table 6, from the end of the last UL subframe among the UL subframes, K symbols represent the idle time including the CCA. It can be used as a symbol for At this time, one or two symbols for UpPTS and UL subframes (in the case of the last UL subframe, K symbols for idle time including CCA are excluded) channel use in a fixed frame period for UL may correspond to time. Hereinafter, a frame structure for LAA according to each UL-DL configuration for LAA will be described in more detail with reference to FIGS. 5 to 10 .

5 is a view showing a frame structure for LAA according to the first embodiment of the present invention.

In FIG. 5, as a first embodiment, a fixed frame period for DL is configured twice within one radio frame (10ms), and a fixed frame period for UL is configured once within one radio frame (10ms). The frame structure for the constructed LAA is shown. This may be based on TDD UL-DL configuration 4.

First, referring to FIG. 5( a ), the fixed frame period for DL is about 4ms in length, and DwPTS (or DL subframe) including 3 DL subframes (14x3 symbols) and 9 or 10 symbols. frame) is made up of Here, DwPTS is the structure of special subframe configuration 2 of Table 5 (10 symbols for DwPTS, 3 symbols for GP and 1 symbol for UpPTS) or the structure of special subframe configuration 6 (for DwPTS) 9 symbols, 3 symbols for GP and 2 symbols for UpPTS). In this case, subframe 7 is the same as subframe 1 (special subframe), 9 or 10 symbols for DL, 3 symbols for idle time including CCA, and 1 not used (not used) Alternatively, it may be composed of two symbols. The three symbols for the idle time including the CCA may be configured based on the GP in the structure of the special subframe configuration 2 or the special subframe configuration 6 of Table 5 above. The unused one or two symbols are not used for the purpose of making the length of the fixed frame period (subframe 8 to subframe 1 and subframe 4 to subframe 7) for the second DL equal to each other. can

On the other hand, the fixed frame period for UL is about 2 ms in length, and 1 or 2 symbols corresponding to UpPTS of subframe 1, 1 UL subframe (14 symbols), and 12 UL subframes in 1 UL subframe. made up of symbols. Here, UpPTS may be configured based on UpPTS in the structure of special subframe configuration 2 or special subframe configuration 6 of Table 5. In this case, two symbols may be used for the idle time including the CCA in subframe 3 . The two symbols for the idle time including the CCA may be configured based on UL configuration 1 (12 UL symbols and 2 symbols for the idle time including the CCA) of Table 6 above.

Next, referring to FIG. 5(b), the fixed frame period for DL is about 4 ms in length, and consists of 3 DL subframes (14x3 symbols) and DwPTS (9 or 10 symbols) or , 3 DL subframes (14×3 symbols) and 11 symbols in one DL subframe. Here, DwPTS may be configured based on DwPTS in the structure of special subframe configuration 2 or special subframe configuration 6 of Table 5. In this case, subframe 7 may consist of 11 symbols for DL and 3 symbols for idle time including CCA. That is, it may be configured based on DL configuration 0 of Table 7 (11 DL symbols and 3 symbols for idle time including CCA). Three symbols for the idle time including the CCA are subframes included in a fixed frame period for the first DL within one radio frame (10ms) (for example, as shown in FIG. 5(b) ) In subframe 1), it may be configured based on the GP in the structure of the special subframe configuration 2 or the special subframe configuration 6 of Table 5, and is fixed for the second DL within one radio frame (10 ms). In a subframe (eg, subframe 7 as shown in FIG. 5(b)) included in the frame period, it may be composed of the last three symbols in the corresponding DL subframe. In this case, the fixed frame period for the UL may be configured to be the same as the fixed frame period for the UL in 5(a).

6 is a diagram illustrating a frame structure for LAA according to a second embodiment of the present invention.

In FIG. 6, as a second embodiment, a fixed frame period for DL is configured twice within one radio frame (10ms), and a fixed frame period for UL is configured once within one radio frame (10ms). The frame structure for the constructed LAA is shown. This may be based on TDD UL-DL configuration 3.

Referring to FIG. 6 , the fixed frame period for DL is about 4 ms in length and consists of 3 DL subframes (14×3 symbols) and DwPTS including 9 or 10 symbols, or as a length of about 3 ms. It consists of two DL subframes (14×2 symbols) and 11 symbols in one DL subframe. Here, DwPTS is the structure of special subframe configuration 2 of Table 5 (10 symbols for DwPTS, 3 symbols for GP and 1 symbol for UpPTS) or the structure of special subframe configuration 6 (for DwPTS) 9 symbols, 3 symbols for GP and 2 symbols for UpPTS). In this case, subframe 7 may consist of 11 symbols for DL and 3 symbols for idle time including CCA. That is, it may be configured based on DL configuration 0 of Table 7 (11 DL symbols and 3 symbols for idle time including CCA). Three symbols for the idle time including the CCA are subframes included in a fixed frame period for the first DL within one radio frame (10ms) (eg, subframe 1 as shown in FIG. 6 ) ) may be configured based on the GP in the structure of the special subframe configuration 2 or the special subframe configuration 6 of Table 5, and a fixed frame period for the second DL within one radio frame (10 ms) In a subframe included in the (eg, subframe 7 as shown in FIG. 6 ), the last three symbols in the corresponding DL subframe may be configured.

On the other hand, the fixed frame period for UL is about 3 ms in length, and 1 or 2 symbols corresponding to UpPTS of subframe 1, 2 UL subframes (14x2 symbols), and 11 symbols within 1 UL subframe is composed of Here, UpPTS may be configured based on UpPTS in the structure of special subframe configuration 2 or special subframe configuration 6 of Table 5. In this case, three symbols may be used for the idle time including the CCA in subframe 4. The three symbols for the idle time including the CCA may be configured based on UL configuration 0 (11 UL symbols and 3 symbols for the idle time including the CCA) of Table 6 above.

7 is a diagram illustrating a frame structure for LAA according to a third embodiment of the present invention.

7, as a third embodiment, a fixed frame period for DL is configured twice within one radio frame (10 ms), and a fixed frame period for UL is configured once within one radio frame (10 ms). The frame structure for the constructed LAA is shown.

First, referring to FIG. 7( a ), the fixed frame period for DL is about 3 ms in length, and DwPTS (or DL subframe) including 2 DL subframes (14×2 symbols) and 9 or 10 symbols. frame) is made up of Here, DwPTS is the structure of special subframe configuration 2 of Table 5 (10 symbols for DwPTS, 3 symbols for GP and 1 symbol for UpPTS) or the structure of special subframe configuration 6 (for DwPTS) 9 symbols, 3 symbols for GP and 2 symbols for UpPTS). At this time, subframe 8 is the same as subframe 1 (special subframe), 9 or 10 symbols for DL, 3 symbols for idle time including CCA, and 1 not used (not used) Alternatively, it may be composed of two symbols. The three symbols for the idle time including the CCA may be configured based on the GP in the structure of the special subframe configuration 2 or the special subframe configuration 6 of Table 5 above.

On the other hand, the fixed frame period for UL is about 4 ms in length, and 1 or 2 symbols corresponding to UpPTS of subframe 1, 3 UL subframes (14x3 symbols), and 11 UL subframes in one UL subframe made up of symbols. Here, UpPTS may be configured based on UpPTS in the structure of special subframe configuration 2 or special subframe configuration 6 of Table 5. In this case, three symbols may be used for the idle time including the CCA in subframe 5. The three symbols for the idle time including the CCA may be configured based on UL configuration 0 (11 UL symbols and 3 symbols for the idle time including the CCA) of Table 6 above.

Next, referring to FIG. 7(b), the fixed frame period for DL is about 3 ms in length, and consists of two DL subframes (14×2 symbols) and DwPTS (9 or 10 symbols) or , 2 DL subframes (14×2 symbols) and 11 symbols in one DL subframe. Here, DwPTS may be configured based on DwPTS in the structure of special subframe configuration 2 or special subframe configuration 6 of Table 5. In this case, subframe 8 may consist of 11 symbols for DL and 3 symbols for idle time including CCA. That is, it may be configured based on DL configuration 0 of Table 7 (11 DL symbols and 3 symbols for idle time including CCA). Three symbols for idle time including the CCA are subframes included in a fixed frame period for the first DL within one radio frame (10ms) (eg, subframe 1 as shown in FIG. 7 ) ) may be configured based on the GP in the structure of the special subframe configuration 2 or the special subframe configuration 6 of Table 5, and a fixed frame period for the second DL within one radio frame (10 ms) In a subframe included in the (eg, subframe 8 as shown in FIG. 7 ), the last three symbols in the corresponding DL subframe may be configured. In this case, the fixed frame period for the UL may be configured to be the same as the fixed frame period for the UL in 7(a).

8 is a diagram illustrating a frame structure for LAA according to a fourth embodiment of the present invention.

FIG. 8 shows a frame structure for LAA in which a fixed frame period for DL and a fixed frame period for UL are configured twice within one radio frame (10 ms), respectively, as a fourth embodiment. This may be based on TDD UL-DL configuration 0.

Referring to FIG. 8 , a fixed frame period for DL has a length of about 2 ms and consists of one DL subframe (14 symbols) and DwPTS including 10 or 11 symbols. Here, DwPTS is the structure of special subframe configuration 3 of Table 5 (11 symbols for DwPTS, 2 symbols for GP, and 1 symbol for UpPTS) or the structure of special subframe configuration 7 (for DwPTS) 10 symbols, 2 symbols for GP and 2 symbols for UpPTS). In this case, the two symbols for the idle time including the CCA may be configured based on the GP in the structure of the special subframe configuration 3 or the special subframe configuration 7 of Table 5, and the last in the corresponding DL subframe. It may consist of two symbols.

On the other hand, the fixed frame period for UL is about 3 ms in length, and 1 or 2 symbols corresponding to UpPTS of subframe 1, 2 UL subframes (14x2 symbols), and 11 symbols within 1 UL subframe is composed of Here, UpPTS may be configured based on UpPTS in the structure of special subframe configuration 3 of Table 5 or the structure of special subframe configuration 7 in Table 5. In this case, three symbols may be used for the idle time including CCA in subframes 4 and 9, respectively. The three symbols for the idle time including the CCA may be configured based on UL configuration 0 (11 UL symbols and 3 symbols for the idle time including the CCA) of Table 6 above.

9 is a diagram illustrating a frame structure for LAA according to a fifth embodiment of the present invention.

9 shows a frame structure for LAA in which a fixed frame period for DL and a fixed frame period for UL are configured twice within one radio frame (10 ms), respectively, as a fifth embodiment. This may be based on TDD UL-DL configuration 1.

Referring to FIG. 9 , a fixed frame period for DL has a length of about 3 ms and consists of two DL subframes (14×2 symbols) and DwPTS including 9 or 10 symbols. Here, DwPTS is the structure of special subframe configuration 2 of Table 5 (10 symbols for DwPTS, 3 symbols for GP and 1 symbol for UpPTS) or the structure of special subframe configuration 6 (for DwPTS) 9 symbols, 3 symbols for GP and 2 symbols for UpPTS). In this case, the three symbols for the idle time including the CCA may be configured based on the GP in the structure of the special subframe configuration 2 or the special subframe configuration 6 of Table 5, and the last in the corresponding DL subframe. It may consist of three symbols.

On the other hand, the fixed frame period for UL is about 2 ms in length, and 1 or 2 symbols corresponding to UpPTS of subframe 1, 1 UL subframe (14 symbols), and 12 symbols in 1 UL subframe is composed of Here, UpPTS may be configured based on UpPTS in the structure of special subframe configuration 2 or special subframe configuration 6 of Table 5. In this case, in subframes 3 and 8, two symbols may be used for each idle time including CCA. The two symbols for the idle time including the CCA may be configured based on UL configuration 1 (12 UL symbols and 2 symbols for the idle time including the CCA) of Table 6 above.

10 is a diagram illustrating a frame structure for LAA according to a sixth embodiment of the present invention.

FIG. 10 shows a frame structure for LAA in which a fixed frame period for DL and a fixed frame period for UL are configured twice in one radio frame (10 ms), respectively, as a sixth embodiment. This may be based on TDD UL-DL configuration 2.

Referring to FIG. 10 , the fixed frame period for DL is about 4 ms in length and consists of 3 DL subframes (14×3 symbols) and DwPTS including 9 or 10 symbols. Here, DwPTS is the structure of special subframe configuration 2 of Table 5 (10 symbols for DwPTS, 3 symbols for GP and 1 symbol for UpPTS) or the structure of special subframe configuration 6 (for DwPTS) 9 symbols, 3 symbols for GP and 2 symbols for UpPTS). In this case, the three symbols for the idle time including the CCA may be configured based on the GP in the structure of the special subframe configuration 2 or the special subframe configuration 6 of Table 5, and the last in the corresponding DL subframe. It may consist of three symbols.

On the other hand, the fixed frame period for UL is about 1 ms in length, and consists of one or two symbols corresponding to UpPTS of subframe 1 and 13 symbols in one UL subframe. Here, UpPTS may be configured based on UpPTS in the structure of special subframe configuration 2 or special subframe configuration 6 of Table 5. In this case, one symbol may be used for each idle time including CCA in subframes 2 and 7. One symbol for the idle time including the CCA may be configured based on UL configuration 2 (13 UL symbols and one symbol for the idle time including the CCA) of Table 6 above.

11 is a flowchart illustrating an operation of a base station according to the present invention.

Referring to FIG. 11, the base station, when CA is configured between the serving cell of the licensed band and the serving cell of the unlicensed band, based on the ratio between UL and DL in the radio frame and the number of changes between UL and DL as shown in FIGS. 5 to 10 At least one of the UL-DL configurations for LAA may be determined as the UL-DL configuration for LLA (S1110). Then, the determined at least one UL-DL configuration information for LLA may be transmitted to the UE as an RRC message (S1120).

Thereafter, the base station checks whether transmission is possible through the corresponding DL resource during the CCA time configured according to the determined UL-DL configuration for LAA, and if transmission is possible through the DL resource, the DL channel (control information, data, etc.) carry out the transmission of In addition, UL channel (control information, data, etc.) reception is performed through a UL resource configured according to the determined UL-DL configuration for LLA (S1130).

Specifically, the base station may configure the UL-DL configuration for LAA based on the UL-DL configuration for TDD as shown in Table 3. For example, if the structure of the fixed frame period for DL is a structure including a special subframe of a TDD radio frame, a DL subframe within one DL-UL switching time according to the TDD UL-DL configuration and the special subframe configuration and DwPTS can be applied as channel usage time in a fixed frame period for DL. In this case, the number of symbols for the idle time including the CCA in the structure of each fixed frame period may be determined according to the length of the channel use time based on Table 4. In this case, the base station may use a special subframe configuration in which the number of symbols for GP and the number of symbols for idle time including CCA are the same as the structure of the special subframe, in which case the special subframe corresponds to the GP. The time may be used as a dwell time including the CCA.

In addition, when the base station configures the UL-DL configuration for LAA based on the UL-DL configuration for TDD as shown in Table 3, the structure of the fixed frame period for DL does not include a special subframe of the TDD radio frame. In the case of , the structure/length of the idle time including the channel usage time for DL and the CCA may be configured to be the same as the structure including the special subframe. Therefore, in the case of the last DL subframe among DL subframes, only a part of symbols in the last DL subframe may be used for DL, and the rest of them may be used as idle time including CCA. In this case, if the last one or two symbols are used as UpPTS in a structure including a special subframe, the last one or two symbols may not be used for DL. That is, the last one or two symbols may be unused symbols.

On the other hand, in configuring the UL-DL configuration for LAA based on the UL-DL configuration for TDD as shown in Table 3, the base station has a fixed frame period for the UL symbol for the idle time including the CCA. It can be determined based on Table 4 according to the length of the channel use time in the structure of the frame period. If the number of symbols corresponding to the idle time including the CCA is determined to be K, the base station uses K symbols from the end of the last UL subframe among the UL subframes as symbols for the idle time including the CCA. can

12 is a flowchart illustrating an operation of a terminal according to the present invention.

Referring to FIG. 12 , when CA is configured between a serving cell of a licensed band and a serving cell of an unlicensed band, the UE may receive an RRC message including UL-DL configuration information for LLA from the base station ( S1210 ). In this case, the UE may check whether transmission through the UL resource is possible through the CCA configured according to the received UL-DL configuration for LAA, or may receive an indication from the base station whether transmission through the UL resource is possible. If it is confirmed that transmission of the UL resource is possible through the CCA in the UL resource configured according to the determined UL-DL configuration for the LLA, the UE configures a UL channel (control information, data, etc.) through the UL resource. The transfer can be performed. Also, the UE may perform reception of a DL channel (control information, data, etc.) through a DL resource configured according to the determined UL-DL configuration for LLA (S1220).

13 is a block diagram illustrating a wireless communication system according to an embodiment of the present invention.

Referring to FIG. 13 , a wireless communication system supporting LAA according to the present invention includes at least one base station 1300 and at least one terminal 1400 .

Each base station 1300 includes a processor 1310 , a radio frequency (RF) unit 1320 , and a memory 1330 .

The memory 1330 is connected to the processor 1310 and stores various information for driving the processor 1310 . The RF unit 1320 is connected to the processor 1310 to transmit and/or receive a radio signal. For example, the RF unit 1320 may transmit information on at least one UL-DL configuration for LAA published in this specification to the terminal 1400 .

The processor 1320 implements the functions, processes and/or methods proposed herein. Specifically, the processor 1320 performs DL transmission and UL reception based on the UL-DL configuration for LAA according to the present specification. For example, the processor 1320 may include a determiner 1311 and a checker 1312 .

The determining unit 1311 determines at least one of the UL-DL configurations for LAA as shown in FIGS. 5 to 10 based on at least one of the ratio between the UL and the DL in the radio frame and the number of changes between the UL and DL in the UL-DL configuration for the LLA. can be determined as For example, when the structure of a fixed frame period for DL is a structure including a special subframe of a TDD radio frame, the determiner 1311 may configure one DL-UL according to the TDD UL-DL configuration and the special subframe configuration. The DL subframe and DwPTS within the transition time may be determined as the channel usage time in a fixed frame period for DL. In this case, the number of symbols for the idle time including the CCA in the structure of each fixed frame period may be determined according to the length of the channel use time based on Table 4. In this case, the determiner 1311 may determine to use a subframe configuration in which the number of symbols for GP and the number of symbols for idle time including CCA are the same as the structure of the special subframe, in which case the special subframe It can be determined that the time corresponding to the GP is used as the idle time including the CCA.

In addition, when the structure of the fixed frame period for DL is a structure that does not include a special subframe of the TDD radio frame, the determiner 1311 determines the structure/length of the idle time including the channel use time and CCA for DL. may be determined to be configured in the same way as the structure including the special subframe. In this case, only a part of symbols in the last DL subframe among DL subframes may be used for DL, and the rest of them may be used as idle time including CCA. In this case, if the last one or two symbols are used as UpPTS in a structure including a special subframe, the last one or two symbols may not be used for DL. That is, the last one or two symbols may be unused symbols.

In addition, the determiner 1311 determines the symbol for the idle time including the CCA in the structure of the fixed frame period for UL based on Table 4 according to the length of the channel use time in the structure of each fixed frame period. have. If the number of symbols corresponding to the idle time including the CCA is determined to be K, K symbols from the end of the last UL subframe among the UL subframes may be used as symbols for the idle time including the CCA. .

The check unit 1312 checks whether transmission is possible through the corresponding DL resource during the CCA time configured according to the UL-DL configuration for LAA determined by the determination unit 1311 . The RF unit 1320 may transmit a DL channel (control information, data, etc.) when it is confirmed by the confirmation unit 1312 that transmission is possible through the DL resource. Also, the RF unit 1320 may perform UL channel (control information, data, etc.) reception through a UL resource configured according to the determined UL-DL configuration for LLA.

Meanwhile, the terminal 1400 includes a radio frequency (RF) unit 1140 , a processor 1420 , and a memory 1430 .

The memory 1430 is connected to the processor 1420 and stores various information for driving the processor 1420 . The RF unit 1410 is connected to the processor 1420 to transmit and/or receive a radio signal. The processor 1420 implements the functions, processes and/or methods proposed herein. In the above-described embodiment, the operation of the terminal 1400 may be implemented by the processor 1420 . When the UL-DL configuration information for LAA published in this specification is received, the processor 1420 performs UL transmission and DL reception accordingly.

To this end, the processor 1120 may include a confirmation unit 1421 and a configuration unit 1422 .

When the UL-DL configuration information for LLA is received from the base station, the check unit 1421 may check whether transmission through UL resources is possible through CCA configured according to the received UL-DL configuration for LAA.

The configuration unit 1422 may configure the UL channel when it is confirmed by the verification unit 1421 that transmission of the UL resource is possible through the CCA in the UL resource configured according to the determined UL-DL configuration for the LLA. The UL channel configured by the configuration unit 1422 may be transmitted to the base station 1300 through the RF unit 1420 .

The above-described processor may include an application-specific integrated circuit (ASIC), another chipset, a logic circuit, and/or a data processing device. Memory may include read-only memory (ROM), random access memory (RAM), flash memory, memory cards, storage media, and/or other storage devices. The RF unit may include a baseband circuit for processing a radio signal. When the present embodiment is implemented in software, the above-described technique may be implemented as a module (process, function, etc.) that performs the above-described function. A module may be stored in a memory and executed by a processor. The memory may be internal or external to the processor, and may be coupled to the processor by various well-known means.

Claims (16)

A communication method of a base station supporting carrier aggregation between a serving cell of a licensed band and a serving cell of an unlicensed band in a wireless communication system, the communication method comprising:
Uplink-downlink configuration having a fixed frame period to be applied to the serving cell of the unlicensed band based on at least one of the number of changes and the proportion between uplink and downlink in a radio frame (radio frame) ( determining an uplink-downlink configuration;
transmitting information on the determined uplink-downlink configuration to the terminal;
Comprising the step of performing uplink reception and downlink transmission according to the uplink-downlink configuration,
For the downlink transmission, when the uplink-downlink configuration having the fixed frame period has a structure including a special subframe, one or more downlinks within one downlink-uplink switching time period Link subframes and a downlink part in the special subframe are used as channel occupancy time, and a guard period part in the special subframe is used as an idle time,
For receiving the uplink, when the uplink-downlink configuration having the fixed frame period includes the special subframe, one or more uplink subs within the one downlink-uplink switching time period Frames and the uplink portion in the special subframe are used as channel usage time, and some of the symbols in the last uplink subframe in the one downlink-uplink switching time period are used as the idle time. how to communicate.
delete delete delete The method of claim 1, wherein when the uplink-downlink configuration having the fixed frame period is a structure that does not include the special subframe,
A communication method according to claim 1, wherein some of the symbols in the last downlink subframe in the one downlink-uplink switching time period are used for the downlink, and the rest is used as an idle time.
6. The method of claim 5,
The communication method, characterized in that the last one or two symbols among the symbols in the last downlink subframe are set as unused symbols.
delete In a communication method of a terminal supporting carrier aggregation between a serving cell of a licensed band and a serving cell of an unlicensed band in a wireless communication system, the communication method comprising:
Information on an uplink-downlink configuration having a fixed frame period determined based on at least one of a ratio between uplink and downlink in a radio frame and the number of changes receiving from the base station;
Comprising the step of performing uplink transmission and downlink reception based on the determined information on the uplink-downlink configuration,
For the downlink reception, when the uplink-downlink configuration having the fixed frame period has a structure including a special subframe, one or more downlinks within one downlink-uplink switching time period subframes and a downlink part in the special subframe are used as channel occupancy time, and a guard period part in the special subframe is used as an idle time,
For the uplink transmission, when the uplink-downlink configuration having the fixed frame period includes the special subframe, one or more uplink subframes within the one downlink-uplink switching time period and the uplink part in the special subframe are used as channel usage time, and some of the symbols in the last uplink subframe within the one downlink-uplink switching time period are used as the idle time. communication method.

delete delete delete The method of claim 8, wherein the receiving of the information on the uplink-downlink configuration comprises:
When the uplink-downlink configuration having the fixed frame period does not include the special subframe, some of the symbols in the last downlink subframe in the one downlink-uplink switching time period are the Used for downlink and the rest is used for idle time.
13. The method of claim 12,
The communication method, characterized in that the last one or two symbols among the symbols in the last downlink subframe are set as unused symbols.
delete In a wireless communication device supporting carrier aggregation between a serving cell of a licensed band and a serving cell of an unlicensed band,
Uplink-downlink configuration having a fixed frame period to be applied to the serving cell of the unlicensed band based on at least one of the number of changes and the proportion between uplink and downlink in a radio frame (radio frame) ( a processor for determining an uplink-downlink configuration) and confirming whether transmission is possible through a serving cell of the unlicensed band according to the determined uplink-downlink configuration; and
When transmission is possible through the serving cell of the unlicensed band, including a radio frequency (RF) unit that performs at least one of uplink reception and downlink transmission according to the uplink-downlink configuration,
The processor is
For the downlink transmission, when the uplink-downlink configuration having the fixed frame period has a structure including a special subframe, one or more downlinks within one downlink-uplink switching time period Link subframes and a downlink part in the special subframe are used as channel occupancy time, and a guard period part in the special subframe is used as an idle time,
For receiving the uplink, when the uplink-downlink configuration having the fixed frame period includes the special subframe, one or more uplink subs within the one downlink-uplink switching time period Frames and the uplink portion of the special subframe are used as channel usage times, and some of the symbols in the last uplink subframe within the one downlink-uplink switching time period are used as idle times. a wireless communication device.

In a wireless communication device supporting carrier aggregation between a serving cell of a licensed band and a serving cell of an unlicensed band,
Information on an uplink-downlink configuration having a fixed frame period determined based on at least one of a ratio between uplink and downlink in a radio frame and the number of changes RF (Radio Frequency) unit for receiving; and
A processor for performing uplink transmission and downlink reception based on the determined uplink-downlink configuration information,
The processor is
For the downlink reception, when the uplink-downlink configuration having the fixed frame period has a structure including a special subframe, one or more downlinks within one downlink-uplink switching time period subframes and a downlink part in the special subframe are used as channel occupancy time, and a guard period part in the special subframe is used as an idle time,
For the uplink transmission, when the uplink-downlink configuration having the fixed frame period includes the special subframe, one or more uplink subframes within the one downlink-uplink switching time period and the uplink portion of the special subframe as channel usage time, and some symbols in the last uplink subframe within the one downlink-uplink switching time period are used as the idle time. communication device.

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