KR20160010848A - Methods for processing the data retransmission and Apparatuses thereof - Google Patents

Abstract

The present invention relates to a data retransmission processing method and apparatus. And more particularly, to a hybrid automatic repeat request (HARQ) operation method and apparatus for a terminal and a base station that perform communication using a license-exempt band cell. In particular, the present invention provides a method for processing data retransmission in a terminal, the method comprising: performing downlink data reception or uplink data transmission in an unlicensed band cell; and performing HARQ Receiving downlink control information including scheduling information for a hybrid automatic repeat request retransmission; And performing a HARQ retransmission operation on downlink data or uplink data in the licensed band cell, wherein the license-exempt band cell is a cell using frequencies of an unlicensed band shared by one or more communication systems .

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data retransmission method,

The present invention relates to a data retransmission processing method and apparatus. And more particularly, to a hybrid automatic repeat request (HARQ) operation method and apparatus for a terminal and a base station that perform communication using a license-exempt band cell.

As the communication system evolved, consumers such as businesses and individuals became using a wide variety of wireless terminals. The current mobile communication system such as LTE (Long Term Evolution) and LTE-Advanced of the 3GPP series is a high-speed and large-capacity communication system capable of transmitting and receiving various data such as video and wireless data beyond voice- It is required to develop a technique capable of transmitting large-capacity data in accordance with the above-described method. On the other hand, techniques are being discussed which allow carrier merging to be applied to various deployment scenarios as a result of the introduction of multiple cells or small cell deployments.

On the other hand, the carrier merging technique is a technique for merging one or more element carriers to transmit and receive data to improve the data transmission / reception ratio. In the terminal, the available frequency is increased and high-capacity data can be processed at a high speed.

However, the frequency for the mobile communication network is limited, and there is a limitation in providing a high-speed large-capacity data transmission / reception rate to a large number of users in a situation where the number of mobile communication subscribers is increased.

In addition, different frequency bands are used by different wireless communication systems depending on the policy, resulting in poor compatibility.

In order to solve the above-described problems, the present invention proposes a method for ensuring reliability of data when different wireless communication systems transmit and receive data using the same frequency band.

In addition, the present invention defines a specific HARQ retransmission operation when a terminal and a base station communicate using a cell using a license-exempt band frequency.

According to another aspect of the present invention, there is provided a method of processing data retransmission by a terminal, the method comprising: performing downlink data reception or uplink data transmission in a license- The method comprising: receiving downlink control information including scheduling information for retransmission of a hybrid automatic repeat request (HARQ); And performing an HARQ retransmission operation on the downlink data or the uplink data in the licensed band cell, wherein the unlicensed band cell is a cell using the frequency of the license-exempt band shared by the one or more communication systems.

The method includes the steps of performing downlink data transmission or uplink data reception in a license-exempt band cell, and performing HARQ (downlink data transmission) when uplink data transmission or uplink data reception fails, The method comprising the steps of: transmitting downlink control information including scheduling information for retransmission of a hybrid automatic repeat request (UL); and performing HARQ retransmission of downlink data or uplink data in a license band cell, Which is a cell using frequencies of an unlicensed band shared by one or more communication systems.

According to another aspect of the present invention, there is provided a terminal for processing data retransmission, comprising: a controller for performing downlink data reception or uplink data transmission in an unlicensed band cell; and a hybrid automatic repeat request (HARQ) and a receiver for receiving downlink control information including scheduling information for a retransmission request, the control unit performing an HARQ retransmission operation for downlink data or uplink data in a license band cell, Which is a cell using a frequency of an unlicensed band shared by one or more communication systems.

According to another aspect of the present invention, there is provided a base station for processing data retransmission, the base station including a control unit for performing downlink data transmission or uplink data reception in a license-exempt band cell and a hybrid automatic repeat request (HARQ) and a transmitter for transmitting downlink control information including scheduling information for a retransmission request, the control unit performing an HARQ retransmission operation for downlink data or uplink data in a license band cell, Which is a cell using frequencies of an unlicensed band shared by one or more communication systems.

The present invention described above provides an effect of ensuring reliability of data when different wireless communication systems transmit and receive data using the same frequency band.

In addition, the present invention provides an effect of preventing ambiguity of a terminal operation by defining a specific HARQ retransmission operation when a terminal and a base station communicate using a cell using a license-exempt band frequency.

1 is an exemplary diagram illustrating a layer 2 structure for downlink carrier merging.
FIG. 2 is an exemplary diagram illustrating a layer 2 structure for uplink carrier merging.
3 is an exemplary diagram illustrating an OFDM symbol for transmitting a control signal in one subframe.
4 is a diagram for explaining self-carrier scheduling and cross-carrier scheduling on a multiple carrier.
5 is a diagram for explaining a downlink control information format.
6 is a diagram for explaining an operation in which a terminal performs communication using a license band and a license-exempt band.
7 is an exemplary diagram for explaining a usable period in a license-exempt band cell.
8 is a diagram for explaining operations of a terminal according to an embodiment of the present invention.
FIG. 9 is a view for explaining an operation of a base station according to another embodiment of the present invention.
10 is a diagram illustrating a configuration of a user terminal according to another embodiment of the present invention.
11 is a diagram illustrating a configuration of a base station according to another embodiment of the present invention.

Hereinafter, some embodiments of the present invention will be described in detail with reference to exemplary drawings. It should be noted that, in adding reference numerals to the constituent elements of the drawings, the same constituent elements are denoted by the same reference numerals whenever possible, even if they are shown in different drawings. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

The wireless communication system in the present invention is widely deployed to provide various communication services such as voice, packet data and the like. A wireless communication system includes a user equipment (UE) and a base station (BS, or eNB). The user terminal in this specification is a comprehensive concept of a terminal in wireless communication. It is a comprehensive concept which means a mobile station (MS), a user terminal (UT), an SS (User Equipment) (Subscriber Station), a wireless device, and the like.

A base station or a cell generally refers to a station that communicates with a user terminal and includes a Node-B, an evolved Node-B (eNB), a sector, a Site, a BTS A base transceiver system, an access point, a relay node, a remote radio head (RRH), a radio unit (RU), and a small cell.

That is, in the present specification, a base station or a cell has a comprehensive meaning indicating a part or function covered by BSC (Base Station Controller) in CDMA, Node-B in WCDMA, eNB in LTE or sector (site) And covers various coverage areas such as megacell, macrocell, microcell, picocell, femtocell and relay node, RRH, RU, and small cell communication range.

Since the various cells listed above exist in the base station controlling each cell, the base station can be interpreted into two meanings. i) the device itself providing a megacell, macrocell, microcell, picocell, femtocell, small cell in relation to the wireless region, or ii) indicating the wireless region itself. i indicate to the base station all devices that are controlled by the same entity or that interact to configure the wireless region as a collaboration. An eNB, an RRH, an antenna, an RU, an LPN, a point, a transmission / reception point, a transmission point, a reception point, and the like are exemplary embodiments of a base station according to a configuration method of a radio area. ii) may indicate to the base station the wireless region itself that is to receive or transmit signals from the perspective of the user terminal or from a neighboring base station.

Therefore, a base station is collectively referred to as a base station, collectively referred to as a megacell, macrocell, microcell, picocell, femtocell, small cell, RRH, antenna, RU, low power node do.

Herein, the user terminal and the base station are used in a broad sense as the two transmitting and receiving subjects used to implement the technical or technical idea described in this specification, and are not limited by a specific term or word. The user terminal and the base station are used in a broad sense as two (uplink or downlink) transmitting and receiving subjects used to implement the technology or technical idea described in the present invention, and are not limited by a specific term or word. Here, an uplink (UL, or uplink) means a method of transmitting / receiving data to / from a base station by a user terminal, and a downlink (DL or downlink) .

There are no restrictions on multiple access schemes applied to wireless communication systems. Various multiple access schemes such as Code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), Orthogonal Frequency Division Multiple Access (OFDMA), OFDM-FDMA, Can be used. An embodiment of the present invention can be applied to asynchronous wireless communication that evolves into LTE and LTE-Advanced via GSM, WCDMA, and HSPA, and synchronous wireless communication that evolves into CDMA, CDMA-2000, and UMB. The present invention should not be construed as limited to or limited to a specific wireless communication field and should be construed as including all technical fields to which the idea of the present invention can be applied.

A TDD (Time Division Duplex) scheme in which uplink and downlink transmissions are transmitted using different time periods, or an FDD (Frequency Division Duplex) scheme in which they are transmitted using different frequencies can be used.

In systems such as LTE and LTE-Advanced, the uplink and downlink are configured on the basis of one carrier or carrier pair to form a standard. The uplink and the downlink are divided into a Physical Downlink Control Channel (PDCCH), a Physical Control Format Indicator CHannel (PCFICH), a Physical Hybrid ARQ Indicator CHannel, a Physical Uplink Control CHannel (PUCCH), an Enhanced Physical Downlink Control Channel (EPDCCH) Transmits control information through the same control channel, and is configured with data channels such as PDSCH (Physical Downlink Shared CHannel) and PUSCH (Physical Uplink Shared CHannel), and transmits data.

On the other hand, control information can also be transmitted using EPDCCH (enhanced PDCCH or extended PDCCH).

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

The wireless communication system to which the embodiments are applied may be a coordinated multi-point transmission / reception system (CoMP system) or a coordinated multi-point transmission / reception system in which two or more transmission / reception points cooperatively transmit signals. antenna transmission system, or a cooperative multi-cell communication system. A CoMP system may include at least two multipoint transmit and receive points and terminals.

The multi-point transmission / reception point includes a base station or a macro cell (hereinafter referred to as 'eNB'), and at least one mobile station having a high transmission power or a low transmission power in a macro cell area, Lt; / RTI >

Hereinafter, a downlink refers to a communication or communication path from a multipoint transmission / reception point to a terminal, and an uplink refers to a communication or communication path from a terminal to a multiple transmission / reception point. In the downlink, a transmitter may be a part of a multipoint transmission / reception point, and a receiver may be a part of a terminal. In the uplink, the transmitter may be a part of the terminal, and the receiver may be a part of multiple transmission / reception points.

Hereinafter, a situation in which a signal is transmitted / received through a channel such as PUCCH, PUSCH, PDCCH, EPDCCH, and PDSCH is expressed as 'PUCCH, PUSCH, PDCCH, EPDCCH and PDSCH are transmitted and received'.

In the following description, an indication that a PDCCH is transmitted or received or a signal is transmitted or received via a PDCCH may be used to mean transmitting or receiving an EPDCCH or transmitting or receiving a signal through an EPDCCH.

That is, the physical downlink control channel described below may mean a PDCCH, an EPDCCH, or a PDCCH and an EPDCCH.

Also, for convenience of description, EPDCCH, which is an embodiment of the present invention, may be applied to the portion described with PDCCH, and EPDCCH may be applied to the portion described with EPDCCH according to an embodiment of the present invention.

Meanwhile, the High Layer Signaling described below includes RRC signaling for transmitting RRC information including RRC parameters.

The eNB performs downlink transmission to the UEs. The eNB includes a physical downlink shared channel (PDSCH) as a main physical channel for unicast transmission, downlink control information such as scheduling required for reception of a PDSCH, A physical downlink control channel (PDCCH) for transmitting scheduling grant information for transmission in a Physical Uplink Shared Channel (PUSCH). Hereinafter, the transmission / reception of a signal through each channel will be described in a form in which the corresponding channel is transmitted / received.

With the introduction of carrier aggregation (CA) technology, a UE can allocate radio resources for uplink or downlink data transmission through a plurality of carriers or serving cells. Accordingly, it is possible to support an improved data transmission rate in comparison with existing communication systems operating in a single carrier or serving cell.

As CA technology is supported, CA-enabled UEs that are in the coverage of a base station that supports CAs are allowed to connect to the primary cell through an initial RRC connection / configuration procedure (RRC connection / configuration procedure) ), And addition / release process of Scand (Secandary cell) through RRC connection reconfiguration process. In addition, the CA-capable UE can additionally use up to five CCs or serving cells through a process of activation / deactivation of scell through MAC CE (Control Element) signaling.

1 is an exemplary diagram illustrating a layer 2 structure for downlink carrier merging. FIG. 2 is an exemplary diagram illustrating a layer 2 structure for uplink carrier merging.

Also, in the case of a UE to which a CA is applied, separate HARQ entities are defined for each CC or serving cell at the time of uplink or downlink data transmission, as shown in FIGS. 1 and 2, The HARQ procedure can be operated.

As each HARQ entity is defined for each CC or serving cell and the HARQ procedure is independently performed for each CC or serving cell, a transport block (TB) in which initial transmission is performed through an arbitrary CC or serving cell And the retransmission is performed through the same CC or serving cell.

3 is an exemplary diagram illustrating an OFDM symbol for transmitting a control signal in one subframe.

Referring to FIG. 3, a control region includes transmission of PHICH, PCFICH, and PDCCH. In this case, the PDCCH is allocated and transmitted in a region where the PDCCH indicated by the PCFICH is uniformly distributed in the number of OFDM symbols to which the PHICH and the PCFICH are allocated, excluding the resources used.

4 is a diagram for explaining self-carrier scheduling and cross-carrier scheduling on a multiple carrier.

Referring to FIG. 4, upon transmission of a PDSCH on a multiple carrier, transmission of a PDSCH indicated by a control channel transmitted in each subframe can be confirmed. FIG. 4A is a diagram showing a self-carrier scheduling operation on multiple carriers, in which a PDSCH is independently scheduled in each carrier. For example, there is a separate PDCCH for each carrier, and the PDCCH of each carrier schedules the PDSCH of the corresponding carrier. That is, data transmission is performed in each carrier by a control channel transmitted in every subframe in 1 ms subframe.

4B is a diagram showing a cross-carrier scheduling operation on multiple carriers, in which the PDSCH is set to be able to schedule PDSCHs for multiple carriers in one carrier. For example, it is possible to schedule a PDSCH in which a PDCCH existing in one carrier can be transmitted on a plurality of carriers. In the case of FIG. 4B, similarly to the case of FIG. 4A, data transmission in multiple carriers is performed by a control channel transmitted every subframe in a 1 ms subframe.

5 is a diagram for explaining a downlink control information format.

Referring to FIG. 5, a downlink control information (DCI) format indicating a scheduling grant for uplink or downlink transmission can be confirmed. DCI formats are separately transmitted according to each uplink or downlink transmission method and usage.

< In the license-exempt zone LTE  Connection using communication technology ( Licensed Assisted Access  using LTE in unlicensed spectrum )>

Mobile telecommunication carriers in each country constitute a wireless cell by exclusively using licensed spectrum frequencies licensed from the government, and provide wireless communication services to the user terminals based on the constitution. Therefore, it is desired to provide high spectral efficiency through technologies such as MIMO, ICIC and CoMP with a radio access technology (RAT) for efficiently using a limited frequency band. In addition, a carrier merging (CA) technique capable of supporting a higher data rate by merging a plurality of carriers existing in a continuous or non-continuous frequency band has been studied.

However, with the recent introduction of mobile devices with high processing power, including smartphones and tablets, mobile traffic of users is rapidly increasing. Therefore, each wireless communication service provider needs a plurality of frequency resources in order to cover the improved mobile traffic. However, licensed band frequency resources are limited or there is a limit depending on the policy situation of each country.

In this situation, there is a growing need to provide LTE / LTE-Advanced services through an unlicensed spectrum, which is used for providing short-range wireless communication services such as WiFi and Bluetooth.

However, in the case of license-exempt bands, unlike licensed bands, many users, including individuals within the regulations of each country, are freely available for the provision of wireless telecommunication services, rather than wireless channels exclusively available to arbitrary operators .

Therefore, signal interference and coexistence with other communication systems may occur when LTE / LTE-Advanced services are provided through the license-exempt band. For example, when a mobile communication service such as LTE is to be provided using a license-exempt band, co-existence with various short-range wireless communication protocols such as WiFi, Bluetooth, NFC, Problems can arise. In addition, co-existence problems may occur with each LTE provider. Therefore, a method for solving such a problem is needed.

For example, when providing an LTE / LTE-Advanced service through a license-exempt band, a wireless channel or a power level of a carrier to be used before transmitting a radio signal to avoid interference or collision between the respective wireless communication services ) To support a radio channel access method based on LBT (Listen Before Talk) for determining whether the corresponding radio channel or carrier can be used. In this case, if the specific radio channel or carrier of the unlicensed band is in use by another wireless communication protocol or another service provider, there is a possibility that the LTE / LTE-Advanced service through the corresponding bandwidth may be restricted. Therefore, unlike the LTE / LTE-Advanced service through the licensed band, the user can not guarantee the desired QoS in the LTE / LTE-Advanced service through the license-exempt band.

6 is a diagram for explaining an operation in which a terminal performs communication using a license band and a license-exempt band.

Referring to FIG. 6, in the case of providing LTE / LTE-A service through the license-exempted band, a licensed-assisted access method LTE (Carrier Aggregation) Service provision may be considered. In this case, the primary carrier supports the FDD or TDD frame structure through the license band, and the secondary carrier configured through the license-exempt band is used for the downlink only Lt; / RTI &gt; Or a secondary carrier configured through a license-exempt band, it may be a form supporting both the uplink and the downlink. That is, the terminal performs the carrier merging to perform the communication, and the primary carrier can process both the uplink and the downlink using the license band dedicated for the mobile communication system. On the other hand, the terminal may process only the downlink dedicated data using a frequency using the license-exempt band as the secondary carrier. Alternatively, the terminal may process both the uplink and downlink data through the secondary carrier.

Hereinafter, for convenience of understanding, a cell configured through the license-exempt band in FIG. 6 will be referred to as a license-exclusion band cell. It should be noted, however, that this is for convenience of description, and is not limited to the name, and may be used to include all the cells of the mobile communication system using the license-exempt band frequency. That is, a license-exempt band cell refers to a cell using an unlicensed band frequency shared by one or more communication systems.

The present invention relates to a method for stably handling data retransmission that may occur in a time period when a frequency of a license-unlicensed band can not be used when communication is performed in a license-exempt band cell using frequencies of an unlicensed band shared by a plurality of communication systems And an apparatus.

7 is an exemplary diagram for explaining a usable period in a license-exempt band cell.

Referring to FIG. 7, in the case of a license-exempt band cell formed by a licensee through a license-exempt band frequency, the frequency band may be a license-exempt band cell formed by another business entity or another wireless connection technology such as WiFi and Bluetooth Access Technology, RAT) system, so the corresponding frequency band can not be used exclusively. Accordingly, when the corresponding frequency band is available through LBT (Listen before talk), it is possible to configure the license-exempt band cell through the frequency band of the license-exempt band for a specific time period to support the terminal. However, even if the license-exempt band cell is configured through the license-exempt band frequency, the frequency band should be emptied for another service provider or another communication system for a specific time after a predetermined time.

In the present invention, for convenience of understanding, as shown in FIG. 7, a time period in which a licensee can construct a license-exempt band cell in an arbitrary frequency band and support a terminal of the corresponding provider is referred to as a license- And the time period in which the license-exempted band cell can not be constructed in the frequency band is referred to as the license-exempted band cell inaccessible period. However, this is also for convenience of explanation, and does not limit the name.

Meanwhile, a terminal access method for a license-exempted band cell configured in an unlicensed spectrum can be configured as a carrier merging or a dual connectivity (DC) together with a normal LTE cell configured in a licensed spectrum have. In this case, a general LTE cell may be composed of a primary cell.

In the case where the license-exempt band cell forms a CA or DC together with a general cell, according to a HARQ operation scheme for a secondary cell defined in an existing CA or DC, an HARQ process independent of the corresponding license- Data transmission / reception should be performed. That is, retransmission of data transmitted through the license-exempt band cell upon failure of reception must be performed through the corresponding license-exempt band cell. In other words, at the time of data transmission / reception for an arbitrary terminal supporting a license-exempted band cell configured in a license-exempted band, an arbitrary transport block constituting the corresponding data is transmitted to a PDSCH or an uplink sub- Frame, if the PDSCH or PUSCH fails to be received, the retransmission for the corresponding transmission block must be performed through the uplink subframe or the downlink subframe of the same license-exempt band cell.

However, if the unlicensed band cell falls into the unlicensed band cell unavailable section for a certain period of time after the initial transmission for the corresponding transmission block, the downlink subframe or the uplink subframe of the license-exempt band cell for retransmission can be secured Do not have A problem arises.

Therefore, a terminal and a base station that perform communication using a license-exempt band cell have a problem in that they can not guarantee reliability of communication data due to data loss or data loss when data is processed according to a conventional data retransmission method.

Accordingly, the present invention proposes a HARQ retransmission scheme capable of securing data reliability even when using a license-exempt band cell. Specifically, the present invention proposes a resource allocation method for PUSCH or PDSCH retransmission, which is an uplink or downlink data channel, in a license-exempt band cell. In particular, we propose a PDSCH or PUSCH retransmission method in each case where cross carrier scheduling and self-carrier scheduling are applied. For example, a cross-carrier scheduling case in which the scheduling control information for the PDSCH or PUSCH of the unlicensed band cell is always transmitted through the PDCCH or the EPDCCH in the license band, and the scheduling control information for the unlicensed band cell are PDCCH or EPDCCH A case in which self-carrier scheduling is directly transmitted through a mobile station is proposed.

Hereinafter, each embodiment of the present invention will be described in detail with reference to the drawings.

8 is a diagram for explaining operations of a terminal according to an embodiment of the present invention.

There is provided a method of processing data retransmission by a terminal, the method comprising: performing downlink data reception or uplink data transmission in a license-exempt band cell and performing hybrid automatic transmission (HARQ) when the downlink data reception or uplink data transmission fails the method comprising the steps of: receiving downlink control information including scheduling information for a retransmission request and performing an HARQ retransmission operation on downlink data or uplink data in a license band cell, Which is a cell using the frequency of the license-exempt band shared by the communication system.

Referring to FIG. 8, the terminal of the present invention includes a step of performing downlink data reception or uplink data transmission in a license-exempt band cell (S810). For example, the terminal may receive downlink data in a license-exempt band cell. Alternatively, the terminal may transmit uplink data in the license-exempt band cell. The terminal may receive only downlink data or only uplink data through a license-exempt band cell according to the configuration of the license-exempt band cell or the configuration of the base station. As another example, a terminal may receive and transmit downlink data and uplink data through a license-exempt band cell. In addition, the terminal can configure the carrier merging using the license band cell and the license-exempt band cell, as described above. Alternatively, the terminal may configure the dual connectivity using the license band cell and the license-exempt band cell. The merging of carriers is a method of establishing a license band cell and a license-exempt band cell in the same base station to perform communication with the terminal. Dual connectivity is a method in which a base station constituting a license band cell and a base station constituting a license- . That is, the present invention can be applied to both cases in which a terminal configures a carrier merging using a license-exempt band cell and a license band cell, and a case in which dual connectivity is configured.

In step S820, the UE may receive downlink control information including scheduling information for HARQ retransmission if downlink data reception or uplink data transmission fails. For example, the terminal may not receive downlink data transmitted by the base station. Or the UE may not normally decode the downlink data transmitted by the base station. In this case, the UE must re-receive data not received from the base station through the HARQ process. The UE must receive the scheduling information related to the radio resource to which the missing data is transmitted in order to re-receive the missing data.

Likewise, when the UE transmits uplink data, it performs an operation according to the HARQ process in order to receive data without missing a base station. That is, if the BS does not normally receive the uplink data transmitted by the MS, the MS must receive the downlink control information including the scheduling information for retransmission from the BS in order to retransmit the missing uplink data. The UE confirms the uplink grant (UL grant) of the received downlink control information and retransmits the missing uplink data through the corresponding radio resource.

If necessary, the downlink control information may include downlink allocation information or uplink grant information. In addition, according to each embodiment to be described in detail below, the downlink control information includes information indicating a cell for retransmission of missing data, information indicating whether a cell is changed for data retransmission, or downlink allocation information Information for instructing retransmission, and the like.

Meanwhile, the UE may perform a HARQ retransmission operation for downlink data or uplink data in a license band cell (S830). For example, if some data in the downlink data received through the license-exempt band cell is missing, the terminal can receive the missing downlink data through the license band cell. Alternatively, if retransmission of uplink data transmitted through a license-exempt band cell is required, the UE may retransmit the uplink data through the licensed band cell. For this, the UE can perform HARQ operation in the license band cell based on the downlink control information received in step S820.

As described above, in the case of transmitting / receiving data through a license-exempt band cell, the terminal can perform stable data transmission / reception even in the presence of the characteristics of the license-exempt band cell (existence of an unusable interval).

Hereinafter, each of the embodiments of the present invention will be described in more detail.

1st Example : Of the licensed band primary  Through the cell HARQ  Perform retransmission.

The terminal of the present invention can perform the HARQ operation through the primary cell of the license band constituting the carrier merging or dual connectivity when HARQ operation for data transmission and reception in the license-exempt band cell is required. In this case, the UE determines whether the downlink assignment or the uplink grant is information for initial transmission of downlink data or uplink data and information for HARQ retransmission operation from the base station Downlink control information including the downlink control information.

For example, when a reception failure occurs in an initial transmission of a PUSCH through a PDSCH or a UL subframe in a DL subframe of a license-exempt band cell, the HARQ retransmission of the PUSCH is performed in the primary cell of the license band And so on. In this case, when dual connectivity is applied in the license band, the primary cell in which the HARQ retransmission for the PDSCH / PUSCH initial transmission of the license-exempt band cell is performed is the primary cell of the MCG (Master Cell Group) Cell group of a cell can be defined as a special cell. Here, MCG denotes a cell group associated with the master base station, and SCG denotes a cell group associated with the secondary base station. In addition, the primary cell has a PUSCH transmission function, can make a RRC connection with the UE, and can mean a cell serving as a reference for handover. The special cell means a cell having a PUSCH function in the secondary cell group, and may be referred to as PSCell or the like.

For example, according to the setting of a new data indicator bit included in a DL assignment DCI for a license-exempt band cell, the corresponding downlink allocation is scheduling information for initial transmission of downlink data And scheduling information for retransmission according to the HARQ operation. That is, if the DL allocation DCI is an initial transmission DL allocation DCI for an HARQ process number according to PDSCH resource allocation control information for initial transmission or PDSCH resource allocation control information for HARQ retransmission, And the PDSCH transmission resource allocation in the unlicensed band cell. In case of downlink allocation DCI for HARQ retransmission for a certain HARQ process number, it can be defined to mean PDSCH transmission resource allocation in the primary cell of the license band.

The HARQ operation for the uplink data may also be performed in a manner similar to that described above.

For example, even in the case of UL grant DCI for a license-exempt band cell, depending on whether a new data indicator bit is set, whether uplink grant information is for PUSCH initial transmission, Whether it is for retransmission or not. That is, if the new data indication bit is UL grant for the initial transmission, it can be defined to mean PUSCH resource allocation in the UL subframe of the license-exempt band cell. Also, if the new data indication bit is an uplink grant for HARQ retransmission, it can be defined to mean PUSCH resource allocation in the primary cell of the license band.

As another example, in the case of retransmission through the PHICH NACK without separately transmitting and receiving the UL acknowledgment for the retransmission, the PUSCH retransmission is performed in the primary cell of the license band according to the UL grant DCI in which the initial transmission for the corresponding HARQ process is performed It can also be defined to be

Meanwhile, the present embodiment can be applied equally regardless of whether self-carrier scheduling or cross-carrier scheduling is applied as a scheduling method for a license-exempt band cell. However, in the case of self-carrier scheduling, when the unlicensed band cell enters the unavailable period at the corresponding HARQ retransmission time, the uplink DCI for downlink allocation DCI or PUSCH retransmission for the corresponding PDSCH retransmission is received The problem can not be solved. Therefore, in this case, it is possible to define that downlink-allocated DCI for the corresponding PDSCH retransmission or uplink-granted DCI for PUSCH retransmission is received through the PDCCH or EPDCCH of the primary cell. Here, a method for distinguishing whether the corresponding DCI is for a primary cell having the same HARQ process number or for retransmission of a PDSCH or a PUSCH of an unlicensed band cell that has entered an unavailable period, The CIF (Carrier Indicator Field) may be defined to be included in the DCI format for a predetermined period of time, and the CIF may be divided. As another example, a new information area may be defined to distinguish the same and may be defined to be included in the corresponding DCI format for a predetermined period of time.

Second Example : Through the scheduling cell of the licensed band HARQ  Perform a retransmission operation

The present embodiment is a method applicable when cross-carrier scheduling for a license-exempted band cell is set up. The HARQ retransmission is performed through a scheduling cell of a license band in which scheduling control information for a PDSCH or a PUSCH of a corresponding license- Can be achieved. That is, based on the Carrier Indicator Field (CIF) information included in the DL allocation DCI transmitted through the license band and the new data indication bit, it is determined whether the corresponding DCI is resource allocation for data initial transmission in the license- The resource allocation for the operation can be distinguished.

For example, if a particular DCI is scheduling information for a license-exempt band cell according to CIF information, and the new data indication bit indicates initial transmission resource allocation information for an HARQ process number, the corresponding PDSCH is allocated a corresponding DL allocation DCI To be transmitted through the license-exempt band cell according to the resource allocation information of the license-unassigned band cell. As another example, if the specific DCI is the scheduling information for the license-exempt band cell according to the CIF information and the new data indication bit indicates the transmission resource allocation for HARQ retransmission, the corresponding PDSCH is allocated to the corresponding license band Lt; / RTI &gt; through the scheduling cell of FIG.

Similarly, in the case of the uplink data, based on the CIF information included in the uplink grant DCI transmitted through the license band and the new data indication bit, whether the corresponding DCI is for the initial transmission or for the HARQ retransmission is performed can do. For example, if the DCI is the scheduling information for the license-exempt band cell according to the CIF and the new data indication bit indicates the initial transmission resource allocation information for the HARQ process number, the corresponding PUSCH is allocated to the resource allocation information of the corresponding UL grant DCI Can be defined to be transmitted through the license-exempt band cell. As another example, if the DCI is the scheduling information for the license-exempt band cell according to the CIF and the new data indication bit indicates transmission resource allocation for HARQ retransmission, the corresponding PUSCH is allocated to the corresponding license band Lt; / RTI &gt; through the scheduling cell of FIG. In the case of retransmission through the PHICH NACK without separately transmitting and receiving the UL grant for the retransmission, the PUSCH retransmission may be defined to be performed in the scheduling cell of the licensed band according to the initial transmission resource allocation information for the PUSCH of the HARQ process number have.

Third Example : License-exempt band  Based on the state of the cell HARQ  Select retransmission cell

In this embodiment, it is possible to determine a cell in which an HARQ retransmission operation is performed according to availability of a license-exempt band cell. That is, if the cell is a usable period according to the state of the license-exempt band cell, retransmission is performed for the PDSCH or the PUSCH through the corresponding license-exempt band cell, and if the cell is not available, Retransmission can be defined to be performed. In the case where retransmission is performed for the PDSCH or the PUSCH using the licensed band cell, the cell in the license band where the HARQ retransmission operation is performed may be the primary cell of the first embodiment or the scheduling cell of the second embodiment.

More specifically, for example, when an unlicensed band cell is in an available period at the time of HARQ retransmission for a PDSCH or a PUSCH in which initial transmission is performed through a license-exempt band cell, the downlink allocation DCI A re-transmission operation can be performed through the DL sub-frame or the UL sub-frame of the license-exempt band cell according to the resource assignment information of the DL assignment DCI or the UL grant DCI. If the unlicensed band cell is an unavailable period at the time of HARQ retransmission for the PDSCH or the PUSCH in which initial transmission is performed through the license-exempt band cell, the HARQ retransmission operation can be performed in the license band cell . That is, according to the first embodiment, the retransmission may be performed through the primary cell of the license band, or the retransmission may be performed in the scheduling cell of the license band by applying the second embodiment.

However, in this embodiment, the state of the license-exempt band cell may be explicitly or implicitly signaled to the terminal. There is no limit to the signaling method.

Fourth Example : Downlink control information ( DCI ) Containing cell change instruction information

The UE of the present invention can receive the cell change indication information included in the downlink control information. For example, in this embodiment, when a downlink allocation DCI or an uplink grant DCI for HARQ retransmission for a PDSCH or a PUSCH that is initially transmitted through a license-exempt band cell is transmitted, a retransmission cell change instruction information area is defined in the corresponding DCI . The UE can confirm whether or not the cell in which the retransmission is performed is changed through the information in the cell change indication information area.

In other words, when a transmission / reception failure occurs for a PDSCH having an arbitrary HARQ process number that has been initially transmitted to a license-exempt band cell, a downlink allocation DCI including PDSCH resource allocation information for HARQ retransmission of the corresponding downlink data, An information area may be defined and signaling to the UE whether the PDSCH retransmission is performed or not may be established. For example, when the corresponding cell change instruction information area is set to "0 ", the corresponding PDSCH retransmission is performed through the corresponding unlicensed band cell. When the cell change instruction information area is set to & The PDSCH retransmission can be set to be performed through the PDSCH. A cell in which PDSCH retransmission is performed may be a primary cell as in the first embodiment, or may be a scheduling cell as in the second embodiment. However, the value of the cell change instruction information area in the above example may be set to various values only for the sake of convenience of understanding.

Also, as described in the third embodiment, when the unlicensed band cell is unavailable at the time of retransmission, the retransmission may be performed through the license band cell regardless of the value of the corresponding cell change indicator information area.

Meanwhile, in the case of retransmission for the PUSCH, the same method as in the case of the PDSCH described above can be applied.

Fifth Example : License-exempt band  For cells HARQ  Disable behavior

In the case of a license-exempt band cell, it is possible to define that the HARQ operation is not performed. That is, the HARQ ACK / NACK feedback for the PDSCH or PUSCH transmission through all the license-exempt band cells is not performed, and the retransmission for transmission / reception failure can be defined to be performed according to the ARQ retransmission of the upper layer.

Or in the case of a usable period according to the state of the license-exempt band cell, the HARQ retransmission can be performed through the corresponding license-exempt band cell. Or if the state of the license-exempted band cell is an available period, the HARQ retransmission operation is performed in the license band cell as described in the first to fourth embodiments, and only when the license- All HARQ processes can be stopped. In this case, the retransmission for the PDSCH or the PUSCH of the HARQ process that does not receive the HARQ ACK can be defined to be performed in the ARQ stage. However, in order to minimize the ARQ retransmission delay, the HARQ process of the discarded license-exempt band cell is regarded as a transmission / reception failure at the ARQ terminal and the status report from the terminal through the license band Can be defined so that retransmission can be performed without receiving the retransmission request.

As described above in detail, the present invention can be performed in the form of one or a combination of the above-described various embodiments with respect to the HARQ procedure of the license-exempt band cell and the HARQ retransmission method therefor. In addition, the names described above are for the purpose of understanding the present invention, and the rights of the present invention are not limited by the corresponding names.

The present invention can be similarly applied to a base station. That is, when the base station transmits the downlink data and receives the uplink data, the description described above based on the terminal can be applied correspondingly or applied equally. The present invention will be briefly described below in terms of a base station.

FIG. 9 is a view for explaining an operation of a base station according to another embodiment of the present invention.

The base station according to another embodiment of the present invention includes a step of performing downlink data transmission or uplink data reception in a license-exempt band cell and a step of performing hybrid automatic repeat request (HARQ) retransmission when downlink data transmission or uplink data reception fails And transmitting the downlink control information including the scheduling information for the downlink data or the uplink data to the license band cell and performing an HARQ retransmission operation for the downlink data or the uplink data in the license band cell. Here, a license-exempt band cell may mean a cell using the frequency of the license-exempt band shared by one or more communication systems.

Referring to FIG. 9, the base station of the present invention includes a step of performing downlink data transmission or uplink data reception in a license-exempt band cell (S910). For example, the base station can transmit downlink data to the terminal and receive uplink data from the terminal. The base station can transmit and receive the downlink data and the uplink data using the above-described unlicensed band cell. In addition, the base station can set or configure the carrier merging or the dual connectivity to the terminal.

If the downlink data transmission or the uplink data reception fails, the base station may transmit downlink control information including scheduling information for HARQ retransmission (S920). For example, when downlink data transmission or uplink data reception fails, downlink control information (DCI) including scheduling information for a data retransmission operation is transmitted. The downlink control information may be transmitted through the license-exempt band cell or the license band cell. That is, when the UE configures the carrier merging and the cross-carrier scheduling is set to operate, the downlink control information can be transmitted through the scheduling cell (licensed band cell).

The downlink control information may include different information according to each of the first to fifth embodiments described above. For example, the downlink control information may include information for identifying whether DL allocation or uplink grant included in the DCI is for data initial transmission or retransmission. In another example, the downlink control information may include cell change indication information indicating whether to change the cell in which the HARQ operation is to be performed. In addition, it may include various kinds of information necessary for carrying out the embodiments of the present invention described above.

The base station may include performing a HARQ retransmission operation on downlink data or uplink data in the licensed band cell (S930). The base station can perform HARQ operations on the data transmitted and received in the license-exempt band cell in the license band cell. Specifically, the base station may perform HARQ retransmission operations in the primary cell or the scheduling cell of the licensed band. Or the base station can perform the HARQ retransmission operation in the license band cell when the license-exempt band cell is in an unavailable interval and the retransmission operation is performed in the corresponding interval. Performing the HARQ retransmission operation means allocating a PDSCH or PUSCH resource for data retransmission in the corresponding licensed band cell.

In addition, the base station can perform all the operations of the present invention described with reference to the first to fifth embodiments.

INDUSTRIAL APPLICABILITY As described above, the present invention provides an effect of ensuring reliability of data when different wireless communication systems transmit and receive data using the same frequency band. In addition, the present invention provides an effect of preventing ambiguity of a terminal operation by defining a specific HARQ retransmission operation when a terminal and a base station communicate using a cell using a license-exempt band frequency.

A configuration of a terminal and a base station capable of performing all of the above-described present invention will be described with reference to the drawings.

10 is a diagram illustrating a configuration of a user terminal according to another embodiment of the present invention.

10, the MS 1000 includes a controller 1010 for performing downlink data reception or uplink data transmission in a license-exempt band cell, and a controller 1010 for performing downlink data reception or uplink data transmission, And a receiving unit 1030 for receiving downlink control information including scheduling information for retransmission of a hybrid automatic repeat request (HARQ). The control unit 1010 controls a HARQ retransmission operation for downlink data or uplink data . Here, a license-exempt band cell means a cell that uses the frequency of the license-exempt band shared by one or more communication systems.

The receiver 1030 receives downlink data, signals, and messages from the base station via the corresponding channel.

Meanwhile, the receiving unit 1030 may receive downlink control information including information necessary for performing HARQ retransmission operations according to each of the above-described embodiments. For example, the downlink control information is classified into whether downlink assignment or uplink grant is information for initial transmission of downlink data or uplink data or information for HARQ retransmission operation Information. In another example, the downlink control information may include cell change indication information indicating whether the cell in which the HARQ retransmission operation is performed is changed.

The control unit 1010 configures the carrier merging or dual connectivity. In addition, the controller 1010 may perform the HARQ retransmission operation in the license-exempt band cell in a period in which the license-exempt band cell is available, and in the license band cell in the period in which the license-exclusion band cell can not be used. Alternatively, the control unit 1010 may determine a cell for performing an HARQ retransmission operation based on the downlink control information, and perform an HARQ retransmission operation in the determined license band cell. In one example, the licensed band cell may be a primary cell or a special cell, or may be a scheduling cell.

In addition, the controller 1010 controls the HARQ in a license-exempt band cell formed through a cell (or a carrier) and a CA (Carrier Aggregation) or a DC (Dual Connectivity) in a licensed spectrum necessary for performing the above- And controls the overall operation of the terminal necessary for defining the retransmission operation.

The transmitter 1130 transmits uplink control information, data, and a message to the base station through the corresponding channel.

11 is a diagram illustrating a configuration of a base station according to another embodiment of the present invention.

11, a base station 1100 according to another embodiment of the present invention includes a controller 1110 for performing downlink data transmission or uplink data reception in a license-exempt band cell, and a downlink data transmission or downlink data reception The control unit 1110 includes a transmitter 1120 for transmitting downlink control information including scheduling information for retransmission of a hybrid automatic repeat request (HARQ) when the downlink data or the uplink It is possible to perform an HARQ retransmission operation on data. Here, a license-exempt band cell means a cell that uses the frequency of the license-exempt band shared by one or more communication systems.

The transmitting unit 1120 and the receiving unit 1130 are used to transmit and receive signals, messages, and data necessary for carrying out the present invention to and from the terminal.

The transmitting unit 1120 may transmit the downlink control information required for performing the HARQ retransmission operation to the UE. For example, the downlink control information is classified into whether downlink assignment or uplink grant is information for initial transmission of downlink data or uplink data or information for HARQ retransmission operation Information. In another example, the downlink control information may include cell change indication information indicating whether the cell in which the HARQ retransmission operation is performed is changed.

The control unit 1110 sets the carrier merging or dual connectivity of the terminal. In addition, the controller 1110 may perform the HARQ retransmission operation in the license-exempt band cell in a period in which the license-exempt band cell is available, and in the license band cell in the period in which the license-exclusion band cell is not available. Alternatively, the controller 1110 may determine a cell for performing an HARQ retransmission operation and control the performance of an HARQ retransmission operation in the determined license band cell. In one example, the licensed band cell may be a primary cell or a special cell, or may be a scheduling cell.

In addition, the controller 1110 controls the HARQ in a license-exempted band cell formed through a cell (or a carrier) and a CA (Carrier Aggregation) or a DC (Dual Connectivity) in a licensed spectrum necessary for performing the above- And controls the overall base station operation required to define the retransmission operation.

The foregoing description is merely illustrative of the technical idea of the present invention, and various changes and modifications may be made by those skilled in the art without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are intended to illustrate rather than limit the scope of the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The scope of protection of the present invention should be construed according to the following claims, and all technical ideas within the scope of equivalents should be construed as falling within the scope of the present invention.

Claims (24)

A method for a terminal to process data retransmission,
Performing downlink data reception or uplink data transmission in a license-exempt band cell;
Receiving downlink control information including scheduling information for a hybrid automatic repeat request (HARQ) retransmission if the downlink data reception or uplink data transmission fails; And
And performing the HARQ retransmission operation on the downlink data or the uplink data in a licensed band cell,
Wherein the license-exempt band cell is a cell using a frequency of an unlicensed band shared by one or more communication systems. The method according to claim 1,
The downlink control information includes:
And information for distinguishing whether the downlink assignment or the uplink grant is information for initial transmission of the downlink data or the uplink data or information for the HARQ retransmission operation Lt; / RTI &gt; The method according to claim 1,
The license band cell includes:
And if the UE is configured for cross-carrier scheduling, the UE is a scheduling cell. The method according to claim 1,
The license band cell includes:
And when the terminal is configured to merge carriers or dual connectivity, the terminal is a primary cell. The method according to claim 1,
The HARQ retransmission operation may include:
Wherein the unlicensed band cell is performed in the unlicensed band cell in a usable period and the unlicensed band cell is performed in the licensed band cell in an unusable period. The method according to claim 1,
The downlink control information includes:
And cell change indication information indicating whether to change the cell in which the HARQ retransmission operation is performed. A method for a base station to process data retransmission,
Performing downlink data transmission or uplink data reception in a license-exempt band cell;
Transmitting downlink control information including scheduling information for retransmission of a hybrid automatic repeat request (HARQ) when the downlink data transmission or the uplink data reception fails; And
And performing the HARQ retransmission operation on the downlink data or the uplink data in a licensed band cell,
Wherein the license-exempt band cell is a cell using a frequency of an unlicensed band shared by one or more communication systems. 8. The method of claim 7,
The downlink control information includes:
And information for distinguishing whether the downlink assignment or the uplink grant is information for initial transmission of the downlink data or the uplink data or information for the HARQ retransmission operation Lt; / RTI &gt; 8. The method of claim 7,
The license band cell includes:
And if the UE is configured for cross-carrier scheduling, the UE is a scheduling cell. 8. The method of claim 7,
The license band cell includes:
Wherein if the terminal is configured for carrier merging or dual connectivity, then the primary cell. 8. The method of claim 7,
The HARQ retransmission operation may include:
Wherein the unlicensed band cell is performed in the unlicensed band cell in a usable period and in the licensed band cell in an unusable unlicensed band cell. 8. The method of claim 7,
The downlink control information includes:
And cell change indication information indicating whether to change the cell in which the HARQ retransmission operation is performed. In a terminal for processing data retransmission,
A controller for performing downlink data reception or uplink data transmission in a license-exempted band cell; And
And a receiver for receiving downlink control information including scheduling information for retransmission of a hybrid automatic repeat request (HARQ) when the downlink data reception or uplink data transmission fails,
Wherein the controller performs the HARQ retransmission operation for the downlink data or the uplink data in a license band cell,
Wherein the license-exempt band cell is a cell using a frequency of an unlicensed band shared by one or more communication systems. 14. The method of claim 13,
The downlink control information includes:
And information for distinguishing whether the downlink assignment or the uplink grant is information for initial transmission of the downlink data or the uplink data or information for the HARQ retransmission operation . 14. The method of claim 13,
The license band cell includes:
Wherein the mobile station is a scheduling cell when cross carrier scheduling is set in the MS. 14. The method of claim 13,
The license band cell includes:
Wherein the terminal is a primary cell when a carrier merging or a dual connectivity is configured in the terminal. 14. The method of claim 13,
The HARQ retransmission operation may include:
Wherein the unlicensed band cell is performed in the license-exempt band cell in a usable section, and the license-cell is performed in an unusable-band-cell-usable section. 14. The method of claim 13,
The downlink control information includes:
And cell change indication information indicating whether the cell in which the HARQ retransmission operation is performed is changed. A base station for processing data retransmission,
A control unit for performing downlink data transmission or uplink data reception in a license-exempt band cell; And
And a transmitter for transmitting downlink control information including scheduling information for retransmission of a hybrid automatic repeat request (HARQ) when the downlink data transmission or the uplink data reception fails,
Wherein the controller performs the HARQ retransmission operation for the downlink data or the uplink data in a license band cell,
Wherein the license-exempt band cell is a cell using a frequency of an unlicensed band shared by one or more communication systems. 20. The method of claim 19,
The downlink control information includes:
And information for distinguishing whether the downlink assignment or the uplink grant is information for initial transmission of the downlink data or the uplink data or information for the HARQ retransmission operation . 20. The method of claim 19,
The license band cell includes:
Wherein the mobile station is a scheduling cell when cross carrier scheduling is set in the UE. 20. The method of claim 19,
The license band cell includes:
Wherein the mobile station is a primary cell when a terminal is configured to merge carriers or dual connectivity. 20. The method of claim 19,
The HARQ retransmission operation may include:
Wherein the unlicensed band cell is performed in the unlicensed band cell in a usable period and in the licensed band cell in an unusable unlicensed band cell. 20. The method of claim 19,
The downlink control information includes:
Wherein the HARQ retransmission operation includes cell change indication information indicating whether a cell in which the HARQ retransmission operation is performed is changed.

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