KR20150114890A - Methods for controlling the secondary cell operation of a mobile station and Apparatuses thereof - Google Patents

Abstract

The present invention relates to a method for a terminal controlling operation of a secondary cell, and to a device for the same. Particularly, the method for the terminal controlling operation of a secondary cell includes the steps of: receiving measurement configuration information for measuring a cell discovery signal; transmitting measurement information of a cell which is measured based on the measurement configuration information and the cell discovery signal; and adding a cell, related to the cell discovery signal, as a secondary cell based on an upper layer signal.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for controlling a secondary cell operation of a terminal,

The present invention relates to a method and an apparatus for controlling a secondary cell operation of a terminal. More particularly, the present invention relates to a method for controlling a secondary cell activation or deactivation operation of a terminal according to ON / OFF instruction information for a corresponding secondary cell received from a base station, the terminal having a cell supporting a ON / OFF function as a secondary cell, And apparatus.

As communications systems evolved, consumers, such as businesses and individuals, used a wide variety of wireless terminals. In a mobile communication system such as LTE (Long Term Evolution) and LTE-Advanced of the current 3GPP series, a high-speed and large-capacity communication system capable of transmitting and receiving various data such as video and wireless data outside a voice- It is required to develop a technique capable of transmitting large-capacity data in accordance with the above-described method. It is possible to efficiently transmit data using a plurality of cells in a method for transmitting a large amount of data.

In such a situation, a technique of expanding a large number of small base stations having a relatively narrow coverage such as a small cell is discussed in order to transmit a large amount of data at a high speed and stably transmit and receive data in an environment in which a plurality of terminals are concentrated in a specific base station In fact. In such an environment where a small base station is deployed, the terminal can improve data processing speed by transmitting and receiving data and signals using a macro base station having a relatively wide coverage with a small base station.

However, since the coverage of the small base station is relatively narrow, it may happen that the terminal does not exist in a small cell at a specific time or at a specific location. Or the small cell may not be used depending on the necessity of data processing of the terminal. Even in such a case, operating the small cell has a problem in that power consumption is wasted throughout the system.

Also, in an environment in which a plurality of small cells are deployed, a reference signal or the like increases, which may cause a problem of inter-cell signal interference.

In addition, when Small Cell uses the license-exempt band, always operating a small cell that uses the license-exempt band violates the regulations of the countries that restrict continuous transmission.

In order to solve the above-described problems, the present invention proposes a concrete operation method and apparatus for adding a cell supporting a terminal on / off function as a secondary cell in an environment in which a plurality of small cells are deployed.

The present invention also provides an operation method and device for controlling a secondary cell activation or deactivation operation of a terminal in accordance with on / off instruction information received from a base station when the terminal adds a cell supporting on / Lt; / RTI >

According to another aspect of the present invention, there is provided a method for controlling a secondary cell operation in a terminal, the method comprising: receiving measurement configuration information for measuring a cell discovery signal; measuring configuration information and a cell measured based on the cell discovery signal; And adding the cell associated with the cell discovery signal to the secondary cell based on the higher layer signal.

According to another aspect of the present invention, there is provided a method of controlling a secondary cell operation of a terminal in a base station, the method comprising: receiving measurement configuration information for measuring a cell discovery signal and measurement information of a cell associated with the measured cell discovery signal based on the cell discovery signal; And transmitting an upper layer signal including information for controlling the terminal to additionally configure a cell associated with the cell discovery signal as a secondary cell.

The present invention also provides a terminal for controlling operation of a secondary cell, comprising: a receiver for receiving measurement configuration information for measuring a cell discovery signal; a transmitter for transmitting measurement configuration information and measurement information of a cell measured based on the cell discovery signal; And a control unit for constructing a cell associated with the cell discovery signal as a secondary cell based on the upper layer signal.

According to another aspect of the present invention, there is provided a base station for controlling a secondary cell operation of a terminal,

A receiving section for receiving measurement configuration information for measuring a cell discovery signal and measurement information of a cell associated with the cell discovery signal measured based on the cell discovery signal and information for controlling the terminal to additionally configure a cell associated with the cell discovery signal as a secondary cell And a transmitter for transmitting an upper layer signal including the higher layer signal.

The present invention described above provides an effect of preventing cell-to-cell signal interference and wasted power consumption of the entire system by adding a cell supporting the on / off function of the terminal as a secondary cell in an environment in which a plurality of small cells are deployed.

In addition, the present invention defines a method of operating a secondary cell of a terminal according to on / off indication information of a base station when a terminal supporting the on / off function is added, And provides an effect of preventing the ambiguity of the secondary cell activation operation of the terminal according to the instruction information.

In addition, the present invention provides a concrete method of transmitting and receiving data as needed in parallel with the on / off function and the activation operation, thereby providing an effect of processing a large amount of data at a high speed.

In addition, the present invention provides an effect of distinguishing and managing the channel occupancy time of the license-exempt band cell through the on / off function of the cell when configuring the license-exclusion band cell as a secondary cell.

FIG. 1 is a view for explaining a method of indicating on / off state of a secondary cell according to an embodiment of the present invention.
FIG. 2 is a diagram for explaining a method of notifying the on / off state of a secondary cell according to another embodiment of the present invention.
3 is a view for explaining a method of indicating on / off state of a secondary cell according to another embodiment of the present invention.
4 is a diagram for explaining operations of a terminal and a base station according to another embodiment of the present invention.
5 is a flowchart illustrating a terminal operation according to another embodiment of the present invention.
6 is a flowchart illustrating an operation of a terminal for receiving a physical layer signal according to another embodiment of the present invention.
7 is a flowchart for explaining another base station operation according to another embodiment of the present invention.
8 is a flowchart illustrating an operation of a base station for transmitting a physical layer signal according to another embodiment of the present invention.
9 is a diagram illustrating a terminal configuration according to another embodiment of the present invention.
10 is a diagram illustrating a base station configuration 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 symbols as 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.

Herein, a small cell refers to a cell having a relatively narrower coverage than a macro cell, and a small cell can be provided by all communication devices providing communication coverage such as a base station or a wireless router. Hereinafter, a small cell may mean a communication device itself providing coverage such as a base station or a wireless router.

Activate / deactivate cell ( activation / deactivation )

In a single base station based Carrier Aggregation (CA) technology or a dual connectivity based on multiple base stations, a small cell may be composed of an additional serving cell or a secondary cell. When a small cell is composed of an additional serving cell or a secondary cell in the UE, an RRC Connection Reconfiguration procedure can be used. When a small cell is configured as an additional serving cell or a secondary cell by a base station, the UE configures the corresponding additional serving cell or secondary cell to be in a deactivated state in a lower layer (UE configure lower layers to consider the SCELL to be in deactivated state. In the case of dual connectivity, the small cell may be composed of secondary cells rather than primary secondary cells. The secondary cell in the following description means that the small cell includes all secondary cells that are not the primary secondary cell in the case of the additional serving cell or the secondary cell or the dual connectivity of the terminal.

Therefore, in order to use the DL Component Carrier and / or the UL Component Carrier of the secondary cell, the additional configured secondary cell must be activated. That is, in order to efficiently manage the battery of the terminal, it is necessary to perform an activation step, which is different from the secondary cell addition or secondary base station addition step, in order for the terminal to further configure the secondary cell.

Activation and deactivation of the secondary cell is performed through a Medium Access Control (MAC) signal. The UE can perform only reference signal received power (RSRP) or reference signal reception quality (RSRQ) measurement without performing CSI (Channel State Information) measurement on the inactivated secondary cell. Through this, it is possible to effectively manage power consumption of the terminal by blocking the execution of CSI measurement which requires a lot of power consumption. Transmission to the uplink element carrier is also disabled for the secondary cell in the inactive state. Since the base station does not schedule the PUSCH for the disabled secondary cell, SRS (Sounding Reference Signal) is not transmitted to the corresponding cell.

When the secondary cell is deactivated, the UE does not transmit the SRS to the secondary cell (not transmit SRS on the SCell) and not to the secondary cell's UL-SCH (not transmit on the UL-SCH on the SCell) A channel quality indicator (CQI), a precoding matrix indicator (PMI), a rank indicator (RI), and a procedure transaction identifier (PTI) report for a secondary cell are not transmitted on the RACH of the secondary cell (Not report the CQI / PMI / RI / PTI for the SCell), but not the secondary cell (not monitor the PDCCH on the SCell) and not perform the PDCCH monitoring for the secondary cell PDCCH for the SCell).

When the secondary cell is activated, normal secondary cell operation (SRS transmissions on the SCell, CQI / PMI / RI / PTI reporting for the SCell, PDCCH monitoring on the SCell and PDCCH monitoring for the SCell) are performed. For example, when the secondary cell is activated, the terminal transmits SRS to the secondary cell, transmits CQI / PMI / RI / PTI to the secondary cell, monitors the PDCCH to the secondary cell, and performs PDCCH monitoring for the secondary cell can do.

Small cell on / off ( On / Off )

When a plurality of small cells overlap with macro cell coverage, the overall system throughput is increased through the cell splitting gain, but inter-cell interference and power consumption are also increased. On the other hand, even when there is no UE connected in the small cell coverage, the small cell continuously transmits a downlink signal including PSS / SSS, PBCH, or CRS, so unnecessary power consumption and interference may occur.

In order to prevent such a situation, the state of the small cell can be dynamically changed. That is, the state of the small cell can be changed to the on state or the off state.

Small cell on / off can be performed for intercell interference adjustment and avoidance, load balancing, energy saving, and the like. In particular, small cell on / off is required in a dense small cell deployment environment.

When the small cell is turned on, the small cell can transmit signals necessary for the terminal to receive data. For example, a small cell in an ON state can transmit signals (for example, CRS, SI, etc.) transmitted from an existing cell in the same manner.

When the small cell is turned off, the small cell may not transmit signals necessary for the terminal to receive data. For example, the small cell in the off state does not transmit some or all of the signals (e.g., CRS, SI, etc.) transmitted in the existing cell. However, even when the small cell is turned off, a discovery signal (e.g., Discovery Reference Signals, DRS) signal for small cell detection or the like can be transmitted. The discovery signal may be used to detect the presence of an off state cell and the discovery signal may be used to measure the radio quality of the off state cell. The discovery signal may be represented by a cell discovery signal. The cell discovery signal described in the present invention is not limited to 3GPP Rel-12 DRS. For example, a signal for detecting a cell that supports any on / off function.

Licensee  Band cell ( unlicensed band cell )

In 3GPP, as a measure to cope with the explosion of mobile data traffic, there is a need for a technology discussion for adding and utilizing a license-exempt frequency band cell as a secondary cell under the support of a licensed band cell. The license-exempt zone is regulated for the fair use of heterogeneous networks, such as Wireless Local Area Network (WLAN) or heterogeneous operators. For example, in Europe and Japan, continuous transmission is prohibited and the maximum duration of a transmission burst is limited. For example, according to European regulations, the maximum channel occupancy should not exceed 13 ms. According to Japanese regulations, maximum channel occupancy should not exceed 4 ms.

In this way, the license-exempt band cell has a limitation on the maximum channel occupation period, and should not occupy the channel for a certain period of time. It may be desirable to use the cell in the off state for periods in which the channel can not occupy. In addition, the cell can be used in an ON state during a period in which the channel can be occupied. That is, with respect to the license-exempted band cell, the base station can operate the period in which the channel of the license-exempt band cell is on and the period in which the channel of the license-exempt band cell can be occupied in the off-state.

The small cell on / off state described above may be determined according to information such as traffic load, user arrival / departure, packet arrival / completion, maximum channel occupancy period regulation of the license-exempt band cell, and the like.

In order to determine the small cell on / off state, the UE in the RRC Connected state can perform Radio Resource Management (RRM) measurement based on the cell discovery signal and report it to the base station.

However, unlike the CRS (Cell-specific Reference Signals) transmitted in each subframe, the DRS transmitted through the small cell in the off state can be transmitted only within a limited subframe. Therefore, when the UE uses the existing CRS-based RRM measurement method as it is, there is a problem in the UE performing the RRM measurement based on the DRS and reporting it. That is, conventionally, since RRM measurement is performed based on the CRS transmitted in every subframe, RRM measurement can not be performed based on DRS of an off-state small cell transmitted within a limited subframe.

On the other hand, according to the 3GPP TR 36.872 document, when the small cell on / off transition time is short, the user throughput gain from the small cell on / off operation can be obtained.

The L1 procedure can be newly defined as one of the ways to reduce the transition time between the on state and the off state. The new L1 procedure can reduce interference in the network by allowing some subframes without downlink data transmission to dynamically turn off in a cell that supports on / off functionality.

However, the specific method of the new L1 procedure for reducing the current small cell on / off transition time is not specified. Therefore, a small cell capable of providing an on / off function through the L1 procedure could not be added as a secondary cell, or data could not be transferred by activating the secondary cell. Particularly, there is a problem that the terminal can perform an operation in an activated state unnecessarily even when the secondary cell supporting the small cell on / off is activated and the small cell is in the off state. Further, even when the secondary cell is inactivated and the small cell is changed to the on-state and operated, there is a problem that the data can not be transmitted quickly due to the terminal operation in the inactive state.

It is an object of the present invention, which is devised to solve such problems, to provide a method for efficiently performing RRM measurement on a mobile station based on a DRS of an off-state small cell transmitted only within a limited subframe and reporting the RRM measurement to a base station . In addition, in the case of transmitting data by adding or activating a small cell supporting the on / off function of the terminal and the base station as a secondary cell, the terminal can effectively transmit and receive data through the L1 procedure for reducing the small cell on / The present invention is directed to providing a method that can be used in a variety of applications.

Specifically, the operation of the small cell and the terminal will be described as follows.

When the small cell is turned off, the small cell can transmit the cell discovery signal. The cell discovery signal may include a plurality of signals for coarse synchronization, cell identification, RRM measurement, and the like.

The UE can perform RRM measurement based on the cell discovery signal for intra-freq / inter-freq for small cell discovery (or small cell on / off decision) transmitting cell discovery signals.

For cell discovery in the cell discovery signal, one or more of PSS, SSS, CRS, CSI-RS, and PRS may be used. Also, one or more of PSS / SSS, CRS, CSI-RS, and PRS may be transmitted for small cell RSRP measurements. Alternatively, information necessary for performing small cell discovery may be provided to the terminal. This information may include at least timing related information of the discovery signal.

For small cell RRM measurements, DRS-based RSRP needs to provide comparable RSRP measurement performance to conventional CRS-based RSRP. Accordingly, the terminal may receive a signal including at least one of a period, an offset, and potentially a duration for the cell discovery signal.

As an example of a procedure for the small cell on / off state transition, a secondary cell activation / deactivation procedure in a handover procedure, a single base station based carrier merging (CA) technology, a secondary base station addition procedure in a dual connectivity technology, Or a secondary cell activation / deactivation procedure by the secondary cell may be used.

As another example of a procedure for small cell on / off state transition, a new Ll procedure may be used to reduce the on / off transition time. The new L1 procedure will be described in detail with reference to the following drawings.

FIG. 1 is a view for explaining a method of indicating on / off state of a secondary cell according to an embodiment of the present invention.

Referring to FIG. 1, information for explicitly indicating a secondary cell on / off state at intervals of a predetermined radio frame (or a subframe) with respect to a secondary cell through a PCell (Primary Cell) can be provided. The terminal can know the ON / OFF state of the corresponding small cell.

For example, in FIG. 1, in the fourth subframe before the start subframe of the radio frame in the radio frame interval, information indicating explicitly indicating the secondary cell on / off state is transmitted in the PCell. In other words, the secondary cell (SCell) can be switched on and off in units of radio frames. To this end, the terminal can receive the instruction information 100 indicating the off state in the PCell. When the UE receives the subframe 100 including the indication information indicating the off state in the PCell, it can know that SCell after 4 subframes is off. Similarly, the UE receives the indication information indicating the on state in the fourth sub-frame 110 and can recognize that the next radio frame is on. Thereafter, when the state of the secondary cell is changed again, the UE can receive the indication information indicating the off state through the 4 th previous subframe 120.

In FIG. 1, the state of a small cell composed of secondary cells is changed in units of radio frames, but the present invention is not limited thereto. In FIG. 1, the state information of the small cell is received through the fourth previous subframe of the subframe in which the radio frame is started. However, this is not intended to limit the present invention. The subframe in which the status information of the small cell is received may be configured in the terminal through the base station or may be a value set in the terminal in advance.

FIG. 2 is a diagram for explaining a method of notifying the on / off state of a secondary cell according to another embodiment of the present invention.

Referring to FIG. 2, in another example of the above-described L1 procedure, when the state of the small cell is changed in units of subframes, information indicating the change may be received. That is, the UE can receive on / off state information of the secondary cell, which is changed in units of subframes, via the PCell. In this case, the terminal can also receive the number information of the subframes maintaining the state.

For example, the UE can receive the status change information through the sub-frame of the second previous PCell of the subframe in which the status of the secondary cell is changed. Specifically, when the small cell configured as the secondary cell is changed from the OFF state to the ON state, the change information can be received through the second all subframes 200 and 210 starting the subframe of the secondary cell changed to the terminal ON state .

Alternatively, status information may be received on a subframe basis in the next radio frame through the second previous subframe 220 of the subframe in which each radio frame is started. That is, the UE can receive information on the number of ON-state subframes (0) through the 220th subframe even if there is no ONF state in the next radio frame.

The above-described state change information may include the number information on the ON-state subframe. That is, the state change information received in the 200 subframe may include information indicating that five subframes are on. Similarly, the status change information received in 210 subframes may include information indicating that six subframes are on. On the other hand, even if there is no on-state sub-frame, information indicating that 0 sub-frames are on, such as state change information received in 220 sub-frames, may be included.

FIG. 2 illustrates the transmission of information indicating explicitly the secondary cell on / off state via PCell in the second sub-frame before the ON-state sub-frame. However, the subframe position including the information explicitly indicating the cell on / off state may have a value different from that shown in Fig. The value may be configured through the base station or may be set in the terminal in advance.

3 is a view for explaining a method of indicating on / off state of a secondary cell according to another embodiment of the present invention.

Referring to FIG. 3, the UE can receive a signal indicating the ON / OFF state of a specific radio frame (subframe) for a secondary cell through a secondary cell. For example, a signal that can recognize the on / off state may be a reference signal or PDCCH, EPDCCH. The terminal can know the small cell on / off state through this.

For example, the terminal can check the ON / OFF state of the small cell configured as the secondary cell by using the state change information received in the specific subframe 300 of the secondary cell. Similarly, the UE can check the on / off state of the small cell configured as the secondary cell using the state change information received in the 310 subframe. The state change information may include the number of subframes to which the state change is applied or the subframe information at which the state change starts. Alternatively, as shown in FIGS. 1 and 2, the position of the sub-frame including the corresponding state change information may be determined in advance.

FIG. 3 shows that information indicating explicitly indicating the secondary cell on / off state is transmitted through the SCell in the on-state starting subframe. However, in the subframe including the information explicitly indicating the cell on / The position may have a value different from that shown in Fig. For example, it may be a sub-frame immediately before the ON-state start sub-frame. Alternatively, the value may be configured through the base station or may be set in the terminal in advance.

The L1 procedure for small cell on / off transition described above is exemplarily shown. The L1 procedure described below may be the L1 procedure described above, or may be another L1 procedure. For example, one of the explicitly ON state or the OFF state may be implicitly recognized by the UE without directing it through physical layer signaling, or a pattern for this may be preconfigured through the RRC configuration information. That is, the on-state is indicated via PCell or SCell, but the off-state may not be pre-set and directed. As another example, the on state may be indicated via PCell, but the off state may be indicated via the corresponding SCell. As another example, a subframe pattern that indicates the on or off state of the SCell through the corresponding SCell, but which can receive the physical layer signal indicating the on or off state of the SCel, , And may be configured in advance through the RRC configuration information. As another example, a duration pattern for the ON state, a duration pattern for the OFF state, and the like may be preset or may be configured in advance through the RRC configuration information.

On the other hand, the terminal can transmit and receive data by configuring the small cells in the ON state as secondary cells. For example, the terminal can perform handover to the small cell in an ON state to transmit and receive data. As another example, the terminal may add a small cell in an ON state as a secondary cell while activating a secondary cell while transmitting an RRC connection with the first base station cell as a PCell, and transmit and receive data. As another example, a terminal may transmit and receive data by adding a small cell, which is a secondary base station cell in an ON state, to a secondary base station cell in an RRC connection through a first base station cell (or a cell associated with the first base station). When the small cell in the ON state is not the primary secondary cell of the secondary base station, the secondary cell can be activated to transmit and receive data.

Hereinafter, specific operations of a terminal and a base station for performing the present invention will be described with reference to the drawings.

4 is a diagram for explaining operations of a terminal and a base station according to another embodiment of the present invention.

Referring to FIG. 4, a first cell 402 denotes a macro cell, and a second cell 403 denotes a small cell. The first cell and the second cell are cells associated with one base station. The terminal 401 receives the measurement configuration information for measuring the cell discovery signal through the first cell 402 (S410). The measurement configuration information may include information necessary for the UE to receive the cell discovery signal, such as the transmission period of the cell discovery signal, the transmission method and the offset information, and to measure the radio signal quality of the cell.

The terminal 401 receives the cell discovery signal from the second cell 403 (S420). The cell discovery signal may be transmitted when the small cell is in the off state as described above, and may be transmitted when the second cell 403 is in the off state.

The terminal 401 may measure the radio signal quality of the cell that transmitted the cell discovery signal based on the received measurement configuration information and the cell discovery signal (S430). The measurement of the radio signal quality for the small cell can be performed by the RRM measurement method as described above.

Meanwhile, the terminal 401 may transmit the measurement information (for example, a measurement report) generated according to the radio quality measurement of the small cell to the base station through the first cell 402 (S440). The base station comprehensively considers the received measurement information and the load of the macro cell and determines whether to add the corresponding small cell to the terminal 401 as a secondary cell.

The base station transmits the secondary cell addition configuration information to the terminal 401 through the first cell 402 (S450). The secondary cell addition configuration information includes information necessary for adding the small cell supporting the on / off function measured by the terminal 401 as a secondary cell, and can be transferred to higher layer signaling. For example, the secondary cell addition configuration information may be included in the RRC connection reconfiguration message and transmitted.

Then, the terminal 401 can perform communication using the small cell added as a secondary cell.

On the other hand, as described above, the small cell can support the on / off function. In addition, the secondary cell can perform data transmission / reception through an activation or deactivation operation. Therefore, if the small cell additionally provided to the terminal as a secondary cell supports the on / off function, it is necessary to define the secondary cell operation of the terminal according to the on / off instruction information of the corresponding cell.

5 is a flowchart illustrating a terminal operation according to another embodiment of the present invention.

In another aspect of the present invention, there is provided a method of controlling a secondary cell operation, the method comprising: receiving measurement configuration information for measuring a cell discovery signal; receiving measurement configuration information and a cell discovery signal; Transmitting the measurement information, and further configuring a cell associated with the cell discovery signal as a secondary cell based on the higher layer signal.

Referring to FIG. 5, the UE of the present invention may include receiving measurement configuration information for measuring a cell discovery signal (S510). It is possible to receive the measurement configuration information necessary for measuring the cell discovery signal transmitted by the small cell in the OFF state. For example, the measurement configuration information may include information necessary for detecting a small cell using a cell discovery signal or for measuring a radio signal quality of a small cell. Alternatively, the measurement configuration information may include the type of the cell discovery signal, the transmission period of the cell discovery signal, the transmission method, and the offset information.

The terminal may include transmitting measurement information of the measured cell's radio signal quality based on the measurement configuration information and the cell discovery signal (S520). For example, the UE can measure the radio signal quality of the small cell that transmits the cell discovery signal using the measurement configuration information and the received cell discovery signal. That is, RSRP or RSRQ of the cell discovery signal of the small cell can be measured. The UE can transmit measured channel condition measurement information to the BS. The wireless signal quality measurement information (e.g., measurement report) is transmitted to the base station that has an RRC connection with the terminal.

The terminal may further comprise configuring a cell associated with the cell discovery signal as a secondary cell based on the higher layer signal (S530). For example, the terminal can additionally configure a secondary cell as a cell to which a cell discovery signal has been transmitted based on an upper layer signal. The higher layer signal may be an RRC message including information related to the additional configuration when the base station further configures the corresponding small cell as a secondary cell based on the channel state measurement information transmitted in step S520. For example, the upper layer signal may be an RRC connection reconfiguration message, and the additional configuration of the secondary cell may be indicated by adding the identifier of the corresponding small cell to the SCellToAddMod field of the RRC connection reconfiguration message. In another example, the additional configuration of the secondary cell may be indicated in a form that includes configuration information for further configuring the license-exempt band cell in the RRC connection reconfiguration message.

On the other hand, as will be described in more detail below, the additional secondary cell may be a cell associated with the master base station or a cell associated with the secondary base station. The secondary cell may be added in the OFF state or may be added in the ON state.

6 is a flowchart illustrating an operation of a terminal for receiving a physical layer signal according to another embodiment of the present invention.

6, the terminal of the present invention includes a step of receiving a physical layer signal including information indicating an on state or an off state of a secondary cell, and a step of activating or deactivating the terminal for the secondary cell based on the physical layer signal And controlling the operation.

For example, as shown in FIG. 5, the terminal may include receiving measurement configuration information for measuring a cell discovery signal (S610). That is, it is possible to receive the measurement configuration information necessary for measuring the cell discovery signal transmitted by the small cell in the OFF state. In addition, the terminal may include transmitting measurement information of the measured cell based on the measurement configuration information and the cell discovery signal (S620). For example, the UE can measure the radio signal quality of the small cell that transmits the cell discovery signal using the measurement configuration information and the received cell discovery signal. In addition, the terminal may further include a step of constructing a cell associated with the cell discovery signal as a secondary cell based on the upper layer signal (S630). For example, the terminal can additionally configure a secondary cell as a cell to which a cell discovery signal has been transmitted based on an upper layer signal.

Meanwhile, the terminal may further include receiving a physical layer signal including information indicating an on state or an off state of the secondary cell (S640). For example, when a small cell is additionally configured as a secondary cell in an ON state or an OFF state as in the following embodiments, the terminal can configure the secondary cell to be in a deactivated state. Thereafter, information indicating the ON state of the corresponding secondary cell can be received from the base station through a physical layer signal (for example, L1 signaling). (Alternatively, after receiving the MAC signal indicating the activation, information indicating the ON state of the corresponding secondary cell can be received through the physical layer signal.) In another example, when the license-exempted small cell is in the ON state When the secondary cell is additionally configured in the off state, the terminal can configure the secondary cell as a license-exempt band cell. Thereafter, information indicating the ON state or the OFF state of the corresponding secondary cell can be received from the base station through a physical layer signal (for example, L1 signaling).

Thereafter, the terminal may include a step of controlling the secondary cell activation operation or the secondary cell activation operation of the terminal based on the physical layer signal (S650). For example, when the physical layer signal includes information indicating the on state of the secondary cell, the terminal may control the secondary cell activation or the secondary cell activation of the terminal for the secondary cell to be performed. The secondary cell activation operation is performed by transmitting an upward reference signal (SRS) transmission operation on a secondary cell, a channel state information (CSI) reporting transmission operation for a secondary cell, a control channel monitoring operation on a secondary cell, And one or more of the control channel monitoring operations for the cell. That is, the terminal may control to perform all of the above-described activation operations, or may control to perform some of the above-described activation operations.

As another example, if the physical layer signal includes information indicating the off state of the secondary cell,

It is possible to perform control so that a part of the terminal deactivation operation or the secondary inactivation operation for the secondary cell is performed. The secondary cell deactivation operation does not transmit the upper reference signal (SRS) on the secondary cell, does not transmit the uplink shared channel on the secondary cell, does not transmit the random access channel on the secondary cell, Means for not performing the channel state information reporting for the cell, not performing the control channel monitoring on the secondary cell, and not performing the control channel monitoring for the secondary cell. That is, the UE may control to perform all of the cell inactivation operations described above, or may control some of them to be performed.

7 is a flowchart for explaining another base station operation according to another embodiment of the present invention.

A method for controlling a secondary cell operation of a terminal, the method comprising: receiving measurement configuration information for measuring a cell discovery signal and radio signal quality measurement information of a cell associated with a measured cell discovery signal based on the cell discovery signal; And transmitting an upper layer signal including information for controlling the terminal to additionally configure the cell associated with the cell discovery signal to be a secondary cell.

Referring to FIG. 7, the base station includes measuring configuration information for measuring a cell discovery signal and receiving measurement information of a cell associated with the measured cell discovery signal based on the cell discovery signal (S710). For example, the base station can receive the radio signal quality measurement information of the small cell measured by the terminal based on the cell discovery signal. If desired, the base station may transmit measurement configuration information including information necessary for the terminal to measure the cell discovery signal. The cell discovery signal is transmitted by the small cell in the off state, and the terminal can measure the small cell detection or the small cell radio signal quality using the cell discovery signal. The UE can then transmit channel state measurement information to the base station. Here, the small cell may be a cell associated with a base station, or may be a cell associated with another base station (e.g., a secondary base station) connected to the base station by an X2 interface.

The base station may include transmitting an upper layer signal including information for controlling the cell to associate the cell discovery signal with the secondary cell (S720). For example, the base station can control the small cell to be additionally configured as a secondary cell of the terminal by taking into consideration the channel state measurement information received from the terminal, the number of terminals located in the small cell or the traffic load. To this end, the base station can transmit information for controlling the secondary cell to be added to the terminal through an upper layer signal. For example, the upper layer signal may be an RRC message and may include the identifier information of the corresponding small cell in the SCellToAddMod field in the RRC connection reconfiguration message. As another example, when a license-exempt band cell is added as a secondary cell, it may be transmitted including configuration information for further configuring a license-exempt band cell in the RRC connection reconfiguration message.

Meanwhile, the base station can determine and control the on / off state change of the small cell. In addition, the secondary cell added to the terminal may be added in the off state or the on state, and may be added to the inactive state or the active state. Alternatively, when adding a license-exempt band cell to the secondary cell, the secondary cell added to the terminal may be added in the off state or the on state, and may be added to the license-exempt band cell.

8 is a flowchart illustrating an operation of a base station for transmitting a physical layer signal according to another embodiment of the present invention.

The base station of the present invention may further include transmitting a physical layer signal including information indicating an on state or an off state of the secondary cell.

Referring to FIG. 8, the base station includes measurement configuration information for measuring a cell discovery signal and measurement information of a cell associated with the measured cell discovery signal based on the cell discovery signal (S810). For example, the base station can receive the radio signal quality measurement information of the small cell measured by the terminal based on the cell discovery signal.

The base station may include a step of transmitting an upper layer signal including information for controlling the terminal to additionally configure a cell associated with the cell discovery signal as a secondary cell (S820). For example, the base station can control the small cell to be additionally configured as a secondary cell of the terminal by taking into consideration the measurement information received from the terminal, the number of terminals located in the small cell or the traffic load.

In addition, the base station may include transmitting a physical layer signal including information indicating an on state or an off state of the secondary cell (S830). The base station can transmit a physical layer signal including information indicating whether the secondary cell further configured to the terminal is on or off. As described above, the secondary cell can be changed to the ON state or the OFF state, and the terminal can configure the secondary cell to be in an activated state or an inactive state. Alternatively, when a license-exempted band cell is added as a secondary cell, the secondary cell can be turned on or off, and the terminal can configure the secondary cell as a license-exempted band cell state.

Therefore, the base station can transmit information instructing the terminal to turn on / off the corresponding secondary cell. In this case, the indication information indicating the ON state or the OFF state transmitted by the base station to the mobile station can be transmitted through the physical layer signal. The physical layer signal may be a signal differentiated from a conventional MAC control element, for example, a physical layer control channel or the like.

For example, a terminal receiving a physical layer signal including information indicating an on state of a secondary cell may perform a secondary cell activation operation or a secondary cell activation operation for a secondary cell configured in addition to the physical layer signal . For example, it is possible to perform at least one of an operation of transmitting an uplink reference signal on a secondary cell, a transmitting operation of reporting channel state information for a secondary cell, a control channel monitoring operation on a secondary cell, and a control channel monitoring operation for a secondary cell have.

.

As another example, the terminal receiving the physical layer signal including the information for controlling the secondary cell to be inactivated may control the terminal to perform a partial deactivation operation or a secondary deactivation operation for the secondary cell. For example, the uplink reference signal is not transmitted on the secondary cell, the uplink shared channel is not transmitted on the secondary cell, the random access channel is not transmitted on the secondary cell, and the channel state information for the secondary cell is not reported , No control channel monitoring on the secondary cell, and no control channel monitoring for the secondary cell.

Hereinafter, a method of additionally configuring the small cell as the secondary cell and a specific method of instructing the activation operation of the secondary cell to be further configured will be described with reference to the respective embodiments.

off  Switching state small cell on state

The terminal or the base station can transmit and receive data by configuring the small cells in the off state as secondary cells according to each of the following embodiments.

1st Example : off  Add / configure cell after transition from on state Procedure  Perform.

The terminal can perform communication by additionally configuring the small cell as a secondary cell after the small cell is changed to the ON state.

For example, when the small cell is in the off state, the small cell can transmit the cell discovery signal. The terminal can detect the small cell in the OFF state based on the cell discovery signal. Alternatively, the terminal can measure the radio signal quality of the off-state small cell based on the cell discovery signal.

The UE measures the small cell radio signal quality and reports the radio signal quality measurement information to the base station. In measuring the radio signal quality of the small cell, the UE can measure the radio signal quality using the measurement configuration information and the cell discovery signal for measuring the cell discovery signal.

The base station can perform on-state switching of the small cell based on traffic load, serving cell load, user arrival / departure, number of users, packet arrival / completion, radio quality or channel status measurement information, You can decide.

If the base station determines to switch the state of the small cell to the ON state, the base station switches the small cell to the ON state when the small cell determined to be turned on is a cell provided by the same base station. Alternatively, when the small cell determining the on-state transition is a cell provided by another base station connected via the X2 interface, the base station transmits display information for switching the small cell to the on-state to the corresponding base station, can do.

Thereafter, the terminal and the base station can transmit and receive data by configuring the small cells in the ON state as secondary cells. For example, the terminal can perform handover to the small cell in an ON state to transmit and receive data. As another example, the terminal may add the on-state small cell as a secondary cell while activating the secondary cell with the RRC connection established with the master base station cell as PCell, and transmit / receive data by activating the secondary cell. As another example, if the terminal adds an on-state small cell, which is an on-state secondary base station cell (or a cell associated with a secondary base station), with an RRC connection through a master base station cell (or a cell associated with the master base station) So that data can be transmitted and received. When the small cell in the ON state is not the primary secondary cell of the secondary base station, the secondary cell can be activated to transmit and receive data.

In order to reduce the on-state transition time, when the small cell for which the base station has decided to switch on state is a cell provided from another base station connected via the X2 interface, the base station turns on the small cell to another base station (for example, State may be included in the handover request message or the secondary base station addition request message and transmitted.

In this way, in the first embodiment, the base station can switch the small cell to be added to the secondary cell in the terminal to the ON state and configure it in the terminal.

Second Example : off  Allow small cell addition / configuration in status.

The terminal can perform communication by additionally configuring the small cell as a secondary cell in a situation where the small cell is in an off state.

For example, when the small cell is in the off state, the small cell can transmit the cell discovery signal. The terminal can detect the small cell in the OFF state based on the cell discovery signal. Alternatively, the terminal can measure the radio signal quality of the off-state small cell based on the cell discovery signal.

The UE measures the small cell radio signal quality and reports the radio signal quality measurement information to the base station. In measuring the radio signal quality of the small cell, the UE can measure the cell discovery signal using the measurement configuration information and the cell discovery signal for measuring the cell discovery signal.

The base station can configure the small cell in the off state as a secondary cell based on the radio quality measurement information. The configuration of the secondary cell as described above includes both cases where the small cell is configured as a serving cell, an additional serving cell, or a secondary base station serving cell.

For example, a base station may transmit an upper layer signal for adding a small cell in an off state to a terminal for a terminal having an RRC connection with a master base station cell as a PCell. For example, the upper layer signal may be an RRC connection reconfiguration message including cell additional configuration information (SCellToAddMod). Cell additional configuration information (or RRC connection reconfiguration message or measurement configuration information or signaling that the base station transmits to the terminal), information indicating that the small cell additionally configured as a secondary cell is off, and / or cell discovery signal measurement of the off- May be included. Alternatively, the cell addition configuration information may not include information indicating that the small cell additionally configured as a secondary cell is in an OFF state. As another example, when a license-exempt band cell is added as a secondary cell, it may be indicated by including configuration information for further configuring a license-exempt band cell in the RRC connection reconfiguration message.

The UE can perform the radio signal quality measurement based on the cell discovery signal for the small cell in the OFF state constituted by the secondary cell. The cell discovery signal can be transmitted at a frequency different from that of the small cell in the off state configured in the secondary cell and in the state in which the secondary cell is not configured in the secondary cell. For example, a cell discovery signal of a small cell in an OFF state composed of a secondary cell can be transmitted more frequently or more rarely than a cell discovery signal of an OFF state small cell not composed of a secondary cell. Alternatively, the transmission frequency of the cell discovery signal may be set to be the same.

The terminal may add the small cell included in the cell addition configuration information as a secondary cell and configure the secondary cell as a disabled state in the lower layer.

The UE may perform an off-state small cell detection and / or an off-state small cell radio signal quality measurement based on the cell discovery signal, and report the radio signal quality measurement information to the base station. Alternatively, the terminal may not perform off-state small cell detection and / or off-state small cell radio signal quality measurement based on the cell discovery signal.

The base station can perform on-state switching of the small cell based on traffic load, serving cell load, user arrival / departure, number of users, packet arrival / completion, radio signal quality or channel state measurement information, You can decide. The base station can switch the small cell to the ON state according to the result of the on-state switching determination described above.

Thereafter, the base station can transmit an Activation / Deactivation MAC Control Element for activating the secondary cell through the PCell.

The base station can transmit and receive data through the activated small cell.

As another example, the ON state transition of the small cell and the activation / deactivation MAC control element transmission of the secondary cell may be performed at the same time.

As another example, the activation / deactivation MAC control element transmission of the secondary cell may occur earlier than the on-state transition of the small cell. The terminal performs actions related to activation / deactivation within the minimum requirements (for delay) specified in 3GPP TS36.133 after the subframe in which the activation / deactivation MAC control element of the secondary cell is received from the base station. The transmission of the MAC control element takes place before the on / off instruction of the small cell in consideration of the delay time until the terminal performs the operation related to the actual activation / deactivation of the activation / deactivation MAC control element of the secondary cell .

In the above example, a case where a small cell is added as a secondary cell has been described as an example. However, in a similar manner, a small cell may be added as a secondary base station cell. Hereinafter, a case where a small cell is added as a secondary base station cell will be described in detail.

For a terminal that has made an RRC connection through a master base station cell, the master base station can transmit an upper layer signal for adding a small cell as a secondary base station cell through a secondary base station addition procedure.

The secondary base station cell in the OFF state can not be constituted by the secondary base station primary secondary cell (SeNB PSCell) which is always active. Alternatively, when there is a cell in the ON state in the secondary base station cell, one of the cells in the ON state in the secondary base station cell may be configured as the secondary base station primary secondary cell. Alternatively, the off-state secondary base station cell may include the on-state secondary base station cell including the information for requesting the on-state switching to the secondary base station addition request message as the secondary base station primary secondary cell, which is always active.

(Or an RRC reconfiguration message or measurement configuration information or signaling to be transmitted to the terminal by the base station) in addition to the information indicating that the small cell additionally constituted by the secondary base station cell is off and / Information for measuring the cell discovery signal of the off-state small cell can be included. Or the information for further configuring the small cell in the OFF state as the secondary base station secondary cell may not include information indicating that the small cell additionally provided in the secondary base station cell is in the OFF state.

The UE can perform the measurement based on the cell discovery signal for the small cell in the OFF state constituted by the secondary base station cell. The cell discovery signal can be transmitted to the small cell in the off state configured by the secondary base station cell at a frequency different from the small cell in the off state not configured in the secondary base station cell. For example, a cell discovery signal of an OFF state small cell composed of a secondary base station cell can be transmitted more frequently or more rarely than a cell discovery signal of an OFF state small cell not configured as a secondary base station cell. Alternatively, the transmission frequency of the cell discovery signal may be set to be the same.

The UE can add the small cell of the secondary base station included in the upper layer signal (for example, the RRC message) as a secondary base station cell and configure the corresponding secondary cell as a deactivated state in the lower layer.

State small cell detection and / or off-state small cell measurement based on the cell discovery signal, and report the radio signal quality measurement information to the base station. Alternatively, the terminal may not perform off-state small cell detection and / or off-state small cell measurement based on the cell discovery signal.

The secondary base station determines the on-state transition of the small cell based on traffic load, serving cell load, user arrival / departure, number of users, packet arrival / completion, channel state measurement information, maximum channel occupancy period of the license-

And the secondary base station switches the corresponding small cell to the ON state.

The secondary base station can transmit an Activation / Deactivation MAC control element for activating the small cell in the off state via the secondary base station primary secondary cell.

The secondary base station can transmit and receive data through the activated small cell.

Third Example : off  State small cell L1 Procedure  Switching on through.

The base station of the present invention can additionally form a small cell in the off state as a secondary cell and can switch to the on state through the L1 procedure. Alternatively, the base station may additionally configure the small cell in the off state as a secondary cell, and allow the terminal to perform the secondary cell activation operation through the L1 procedure.

When the small cell is in the OFF state, the small cell can transmit the cell discovery signal.

The UE can perform the off-state small cell detection and / or the off-state small cell radio signal quality measurement based on the cell discovery signal.

The terminal reports the radio signal quality measurement information to the base station.

The base station can configure the small cell in the off state as a secondary cell based on the radio signal quality measurement information. Here, the secondary cell is meant to include both the above-described serving cell, the additional serving cell, or the secondary base station cell.

For example, an RRC connection reconfiguration (RRC connection reconfiguration) message including cell addition configuration information (SCellToAddMod) for adding a small cell in an OFF state to a secondary cell, Message) to the terminal. The terminal adds the small cell included in the cell addition configuration information as a secondary cell and configures the secondary cell as a disabled state in the lower layer.

As another example, when the small cell has been turned on, the terminal can add the small cell as a secondary cell and configure the secondary cell to be considered as inactive.

As another example, when a license-exempted band cell is added as a secondary cell, the base station can transmit the RRC connection reconfiguration message including the configuration information for configuring the license-exempt band cell to the terminal. When the terminal adds the license-exempted band small cell to the secondary cell, the license-exempt band cell may be on-state (a period in which the license-exempt band cell channel can be occupied or a period in which the license-exempt band cell is available) When added as a cell, the license-exempt band cell may be in an off state (a period during which the channel occupancy of the license-exempt band cell is impossible or a period during which the license-exclusion band cell is unavailable). The terminal may configure the corresponding license-exempted secondary cell to be deactivated, or the terminal may configure the corresponding license-exempted secondary cell to a specific state for the license-exempted band. The specific state for the license-exempted band is that the terminal according to the present invention transmits a part of the normal secondary cell operation (for example, PDCCH monitoring for the corresponding secondary cell or another example, SRS transmission operation for the secondary cell, , A CQI / PMI / RI / PTI reporting operation for the secondary cell, a PDCCH monitoring operation for the secondary cell, and a PDCCH monitoring operation for the secondary cell).

The base station determines the switch-off state of the small cell based on traffic load, serving cell load, user arrival / departure, number of users, packet arrival / completion, radio signal quality measurement information, maximum channel occupancy period of the license- The UE can perform the off-state small cell detection and / or the off-state small cell radio signal quality measurement based on the cell discovery signal, and report the radio signal quality measurement information to the base station. Alternatively, the terminal may not perform off-state small cell detection and / or off-state small cell measurement based on the cell discovery signal.

Alternatively, the base station determines the on-state transition of the small cell based on traffic load, serving cell load, user arrival / departure, number of users, packet arrival / completion, measurement report, maximum channel occupancy period of the license- The base station switches the corresponding small cell to the ON state.

In this case, the information indicating the on state of the corresponding secondary cell can be transmitted through the physical layer signal (L1 procedure).

For example, the base station may activate a secondary cell of the terminal by performing a new L1 procedure to reduce the time required for the terminal and the small cell on / off transition through the PCell. That is, when the terminal receives the physical layer signal indicating the on state of the secondary cell with respect to the corresponding secondary cell, the terminal can perform a normal secondary cell operation or a part of the normal secondary cell operation with respect to the secondary cell.

As another example, the base station can perform a new L1 procedure to reduce the time required for the small cell ON / OFF transition with the terminal through the PCELL to turn the small cell in the OFF state into the ON state and activate the secondary cell operation in the terminal. That is, when the terminal receives the physical layer signal indicating the on state of the secondary cell with respect to the corresponding secondary cell, the terminal can perform a normal secondary cell operation or a part of the normal secondary cell operation with respect to the secondary cell.

As another example, the base station may perform a new L1 procedure to reduce the small cell on / off transition time through the PCcell to switch the small cell in the off state to the on state, and if the terminal performs one or more of the normal secondary cell operations As shown in FIG.

As another example, the base station may perform a new L1 procedure to reduce the time of the small cell on / off transition between the terminal and the terminal through the PCell, so that the terminal may perform one or more operations of the normal secondary cell operation.

As another example, the base station may perform a new L1 procedure to reduce the small cell on / off transition time with the terminal through the PCell so that the terminal in the inactive state performs one or more of the normal secondary cell operation with the base station can do.

As another example, the base station may perform a new L1 procedure to reduce the small cell on / off transition time through the SCell to switch the small cell in the off state to the on state, and if the terminal performs one or more of the normal secondary cell operations As shown in FIG.

As another example, the base station may perform a new L1 procedure to reduce the small cell on / off transition time with the terminal through the serving cell to switch the small cell in the off state to the on state, So as to perform an operation.

The normal secondary cell operation as described above includes SRS transmissions on the SCC on the secondary cell, CQI / PMI / RI / PTI reporting on the secondary cell (CQI / PMI / RI / PTI reporting for the SCell) , A PDCCH monitoring on the SCell on the secondary cell, and a PDCCH monitoring for the SCC on the secondary cell.

Thereafter, the base station can transmit and receive data to and from the terminal through the small cell.

The on-state switching of the small cell and the L1 procedure described above may be performed at the same time. Alternatively, the L1 procedure may occur earlier than the on-state transition of the small cell. For example, after the UE receives the physical layer signal (L1 procedure) and performs the L1 procedure in consideration of the delay time from when the mobile station performs the on-state operation in the corresponding secondary cell to when the mobile terminal performs the operation related to the activation (E.g., after a certain sub-frame, after another predefined constant sub-frame, for example).

Hereinafter, the operation of the terminal and the base station will be described once again when the above-mentioned small cell is a cell associated with the secondary base station. That is, the case where the above-described small cell is added to the secondary base station cell will be described.

In this case, the master base station can transmit an RRC connection reconfiguration message to the terminal for adding the off-state small cell to the secondary base station cell through the secondary base station addition procedure for the terminal that has made the RRC connection through the master base station cell.

For example, the secondary base station cell in the OFF state can be controlled so as not to consist of the secondary base station primary secondary cell, which is always active.

As another example, when there is a cell in the ON state in the secondary base station cell, one of the cells in the ON state in the secondary base station cell may be configured as the secondary base station primary secondary cell.

As another example, the off-state secondary base station cell may include information for requesting on-state switching to the secondary base station addition request message so that the on-state secondary base station cell is always configured as a secondary base station primary secondary cell have.

As another example, the off-state secondary base station cell may be configured as a secondary base station primary secondary cell. In this case, the secondary base station can perform the above-described L1 procedure through the secondary base station primary secondary cell. That is, the primary base station primary secondary cell can be switched to the active state, the ON state, or the ON state through the L1 procedure, so that the terminal can perform at least one of the normal secondary cell operations to transmit and receive data. The UE can monitor the PDCCH during the cell discovery signal measurement period so that the secondary base station can perform the L1 procedure through the secondary base station primary secondary cell. Alternatively, the UE may monitor the PDCCH at a specific point in time.

In another example, the UE adds the small cell of the secondary base station included in the RRC message to the secondary base station secondary cell and configures the corresponding secondary cell to the inactive state in the lower layer.

The UE may then perform an off-state small cell detection and / or an off-state small cell channel state measurement based on the cell discovery signal, and report the channel state measurement information to the base station. Alternatively, the terminal may not perform the off-state small cell detection and / or the off-state small cell channel state measurement based on the cell discovery signal.

The secondary base station can determine the on-state transition of the small cell based on traffic load, serving cell load, user arrival / departure, number of users, packet arrival / completion, measurement report, maximum channel occupancy period of license-

And the secondary base station switches the corresponding small cell to the ON state.

In this case, the information indicating the on state of the corresponding secondary cell can be transmitted through the physical layer signal (L1 procedure).

For example, the secondary base station can activate the small cell operation of the terminal by performing a new L1 procedure to reduce the time required for the small cell ON / OFF transition with the terminal through the secondary base station primary secondary cell. That is, when the terminal receives the physical layer signal indicating the on state of the secondary cell with respect to the corresponding secondary cell, the terminal can perform a normal secondary cell operation or a part of the normal secondary cell operation with respect to the secondary cell.

In another example, the secondary base station performs a new L1 procedure for reducing the small cell ON / OFF transition time with the terminal through the secondary base station primary secondary cell to switch the small cell in the OFF state to the ON state, Can be activated. That is, when the terminal receives the physical layer signal indicating the on state of the secondary cell with respect to the corresponding secondary cell, the terminal can perform a normal secondary cell operation or a part of the normal secondary cell operation with respect to the secondary cell.

In another example, the secondary base station performs a new L1 procedure for reducing the small cell on-off transition time with the terminal through the secondary base station primary secondary cell, thereby switching the small cell in the off state to the on state, To perform one or more operations during operation.

As another example, the secondary base station may perform a new L1 procedure for reducing the small cell on-off transition time with the terminal through the secondary base station primary secondary cell to perform one or more of the ordinary secondary cell operations.

The normal secondary cell operation as described above includes SRS transmissions on the SCell for the secondary cell, CQI / PMI / RI / PTI reporting for the secondary cell (CQI / PMI / RI / PTI reporting for the SCell) A PDCCH monitoring for the secondary cell and a PDCCH monitoring for the secondary cell may be included in the secondary cell.

The secondary base station can transmit and receive data through the small cell.

The on-state switching of the small cell and the L1 procedure described above may be performed at the same time. Alternatively, the L1 procedure may occur earlier than the on-state transition of the small cell. For example, after the UE receives the physical layer signal (L1 procedure) and performs the L1 procedure in consideration of the delay time from when the mobile station performs the on-state operation in the corresponding secondary cell to when the mobile terminal performs the operation related to the activation (E.g., after a certain sub-frame, after another predefined constant sub-frame, for example).

Fourth Example : On state cell in active state L1 Procedure  through off  Switch to state

When the small cell is on, the terminal can transmit and receive data through the small cell. For example, the mobile station can perform handover to an ON-state small cell to transmit and receive data. As another example, the terminal may add the on-state small cell as a secondary cell while activating the secondary cell with the RRC connection established with the master base station cell as PCell, and transmit / receive data by activating the secondary cell. As another example, if the terminal adds an on-state small cell, which is an on-state secondary base station cell (or a cell associated with a secondary base station), with an RRC connection through a master base station cell (or a cell associated with the master base station) So that data can be transmitted and received. When the small cell in the ON state is not the primary secondary cell of the secondary base station, the secondary cell can be activated to transmit and receive data. As another example, if the small cell in the on state or the off state is a license-exempt band cell, the terminal can transmit / receive data by performing the secondary cell activation operation in the on state when the license-exclusion band cell is configured.

The base station can determine the switch-off state of the small cell based on the traffic load, the serving cell load, the user arrival / departure, the number of users, the packet arrival / completion, the measurement report, and the maximum channel occupancy period of the license-

For example, the base station keeps the small cell in the ON state when there is a terminal having an RRC connection with the small cell of the ON state as the PCell. If there is a terminal that has an RRC connection with a small cell as a PCell, the terminal may generate an RLF (Radio Link Failure) when the small cell is turned off. In this case, it is possible to move the terminal to another cell through handover and determine the switching state of the cell.

As another example, the base station may add a small cell in the ON state as a secondary cell, and determine that the small cell is in an OFF state when the number of configured terminals is within a predetermined number. Alternatively, the base station may add a small cell in the ON state as a secondary cell, and may determine that the small cell is in the OFF state when the amount of the forwarding packets of the configured terminals is less than a predetermined level. Alternatively, the base station may add a small cell in the ON state as a secondary cell, and determine that the small cell is in an OFF state when a packet to be delivered to the configured UE has not arrived.

As another example, if there is a legacy terminal before Release 12 configured by adding a small cell in the ON state as a secondary cell, if the corresponding small cell is in the inactive state, (For example, when the number of Release 12 terminals is within a certain number, or when the amount of forwarded packets of the terminals is less than or equal to a certain level), it is possible to determine an OFF state transition . For example, if the number of terminals in the active state is within the reference number, or if the amount of forwarded packets of the terminals is less than a certain level, or if the packet to be delivered to the terminal does not arrive, the off state switching can be determined for the active secondary cell . Legacy terminals prior to Release 12 perform CRS-based measurements only, and measurements based on cell discovery signals can not be performed. If the small cell added as the secondary cell is switched to the off state, the legacy terminal before Rel-12 can not perform the CRS-based measurement and can not perform the DRS-based measurement through the small cell in the off state have. Therefore, the base station can consider the number of legacy terminals before Rel-12 or the configuration state of legacy terminals before Release 12 in determining small cell on / off. In addition, the base station can cause the secondary cell cancellation to be performed first before switching the secondary cell to the off state.

As another example, the secondary base station can determine the switch-off state of the corresponding small cell when the number of terminals configured by adding the small cell as the secondary base station secondary cell is less than a predetermined number or when the amount of the forwarding packets of the terminals is less than a predetermined level have.

As another example, if there is a legacy terminal before Release 12 configured by adding a small cell in the ON state as a secondary base station secondary cell, if the corresponding small cell is in the inactive state, (For example, when the number of Rel-12 UEs is within a certain number, or when the amount of forwarded packets of the UEs is below a certain level, or when a packet to be delivered to the UE is not reached , It is possible to decide to switch the off state of the secondary cell. Legacy terminals prior to Rel-12 perform only CRS-based measurements and can not perform cell discovery signal-based measurements. Therefore, when the small cell added as the secondary base station secondary cell is turned off, the legacy terminal before Rel-12 can not perform the CRS-based measurement and can perform the cell discovery signal based measurement through the small cell in the off state There can be no problems. Therefore, the base station can consider the number of legacy terminals before Rel-12 or the configuration state of legacy terminals before Rel-12 in determining small cell on / off. In addition, the base station can cause the secondary cell cancellation to be performed first before switching the secondary cell to the off state.

As another example, when using a license-exempt band cell, the base station can determine the switch-off state of the small cell when the period in which the license-exempt band cell channel is available or the period in which the license-exempt band cell is available expires.

Based on the above-described method of determining the off state, the base station switches the small cell to the off state.

For example, if the corresponding small cell is a secondary cell (or is a secondary cell when dual connectivity is applied, or is a secondary cell that is not a primary secondary cell when dual connectivity is applied), the terminal may perform a normal secondary cell operation As shown in FIG. The normal secondary cell operation includes SRS transmissions on the SCL for the secondary cell, CQI / PMI / RI / PTI reporting for the secondary cell, , A PDCCH monitoring on the SCell in the secondary cell, and a PDCCH monitoring for the SCC on the secondary cell.

However, when the small cell is switched to the off state in a state in which the corresponding secondary cell is configured to be active in the terminal, it may be inefficient to perform all or a part of the normal secondary cell operation in the active state. Also, when the small cell is in the off state, an error may occur when the secondary cell configured in the terminal performs the conventional secondary cell operation in the active state. That is, when the small cell is turned off and only the cell discovery signal is transmitted, the terminal can not perform a normal conventional secondary cell operation and an error may occur when performing the normal secondary cell operation described above. Accordingly, when the secondary cell is in the active state and the small cell is switched to the off state, the terminal and the base station need to perform the following operations.

For example, the BS may deactivate the operation of the small cell of the UE by performing a new L1 procedure for decreasing the small cell on / off transition time through the PCcell (or PSCell cell or SCell). That is, when the terminal receives the physical layer signal indicating the off state of the secondary cell with respect to the corresponding secondary cell, the terminal performs a secondary cell operation in the inactive state or a part of the inactive state secondary cell operation with respect to the corresponding secondary cell .

As another example, the base station may perform a new L1 procedure to reduce the small cell on / off transition time through the PCell (or PSCell cell or SCell) to switch the on-state small cell to the off state, Can be deactivated. That is, when the terminal receives the physical layer signal indicating the off state of the secondary cell with respect to the corresponding secondary cell, the terminal performs a secondary cell operation in the inactive state or a part of the inactive state secondary cell operation with respect to the corresponding secondary cell .

As another example, the base station may instruct the switching of the on-state small cell to the off state by performing a new L1 procedure to reduce the small cell on / off transition time through the PCcell (or PSCell cell or SCell) So that a corresponding operation can be performed. For example, the UE can confirm that the secondary cell configured in the active state is changed from the ON state to the OFF state through the L1 procedure described above. In this case, the terminal recognizes that the secondary cell configured in the terminal is switched to the off state through the L1 procedure indicating the off state of the secondary cell, and the terminal can perform one or more operations during the operation when the secondary cell is inactivated . For example, the UE does not perform transmission via the secondary cell (not transmit SRS on the SCell, not transmit on UL-SCH on the SCell, not transmit on the RACH on the SCell) (Not report CQI / PMI / RI / PTI for the SCell) without performing a CQI / PMI / RI / PTI report for the secondary cell. However, the UE can perform the PDCCH for the secondary cell through the PCell. As another example, the UE does not perform transmission on the secondary cell (not transmit SRS on the SCell, not transmit on the UL-SCH on the SCell, not transmit on the RACH on the SCell) Monitoring and / or PDCCH monitoring for the secondary cell through PCell. As another example, the random access procedure through the secondary cell may not be performed. Alternatively, the random access procedure can be performed through the primary cell. Alternatively, the random access procedure through the secondary cell may be suspended. As another example, the scheduling request (SR) procedure through the secondary cell may not be performed. Alternatively, the scheduling request procedure may be performed through the primary cell. Alternatively, a scheduling request (SR) procedure via a secondary cell may be suspended.

The activation of the secondary cell of the terminal by the MAC Control Element of the conventional 3GPP TS 36.321 follows the timing related standard of 3GPP TS 36.213. The TS 36.213 timing specifications are as follows.

When a terminal receives an activation command for a secondary cell in subframe n, the corresponding actions are applied to subframe n + 8, with the exception of the minimum requirements defined in 3GPP TS 36.133, It should be applied not too late and not faster than sub-frame n + 8.

Actions related to -CSI reporting

- actions associated with the sCellDeactivationTimer associated with the secondary cell

The minimum requirements defined in 3GPP TS36.133 are as follows.

For the SCell activation delay requirement, if the terminal sends a valid measurement report during the same period as max (5 measCycleSCell, 5 DRX cycles) before receiving the SCell activation command and the SCell remains in a detectable state, it is later than subframe n + 24 Otherwise, the terminal must be able to apply the operation no later than subframe n + 34.

Thus, the UE has a delay time until it receives an active MAC Control element and performs operations for actual activation. Accordingly, when instructing the terminal to turn on / off the cell through the physical layer signal, the terminal may perform a related operation in a state where the cell can perform the normal secondary cell operation in the activated state. For example, indicating the on or off state of the secondary cell via PCell (or via SCell), indicating the duration of the on-state and on-state of the secondary cell via another example, PCell (or via SCell) A duration pattern for on-state or a pattern for on-off state, a duration pattern for on-off state, or a duration pattern for on-off state are preset or pre-configured through RRC configuration information, When recognizing the state, the terminal recognizes the ON / OFF state information of the cell or the ON / OFF state of the cell in a state where the cell can perform a normal secondary cell operation or a part of a normal secondary cell operation , It is possible to perform or change some operations of the related secondary cell terminal operation.

For example, the terminal may add a small cell in an off state as a secondary cell, and configure the secondary cell to be considered in an inactive state.

The base station activates the corresponding secondary cell through the MAC Control element.

The base station switches the corresponding secondary cell to the ON state through the above-described physical layer signaling (L1 procedure).

The activation of the corresponding secondary cell via the MAC Control element and the on-state transition of the corresponding secondary cell may be initiated at the same time or may be started at the same time (as in the present invention, the secondary cell may be in the cell- The secondary cell activation may be initiated first.

When the base station determines to switch the off state of the corresponding secondary cell, the base station switches the corresponding secondary cell to the off state through the above-described physical layer signaling (L1 procedure). Or the base station and the terminal recognize the switch-off state of the corresponding secondary cell.

The terminal performs a part of the secondary cell deactivation operation or the secondary cell deactivation operation.

If the base station determines that the corresponding secondary cell is turned on, the base station switches the corresponding secondary cell to the on state through the above-described physical layer signaling (L1 procedure). Or the base station and the terminal recognize that the corresponding secondary cell is turned on.

The terminal performs a part of the secondary cell activation operation or the secondary activation operation.

As another example, when a license-exempted band cell is added as a secondary cell, the base station can transmit the RRC connection reconfiguration message including the configuration information for configuring the license-exempt band cell to the terminal. When the terminal adds the license-exempted band small cell to the secondary cell, the license-exempt band cell may be on-state (a period in which the license-exempt band cell channel can be occupied or a period in which the license-exempt band cell is available) When added as a cell, the license-exempt band cell may be in an off state (a period during which the channel occupancy of the license-exempt band cell is impossible or a period during which the license-exclusion band cell is unavailable).

The terminal can be configured to consider the corresponding license-exempted secondary cell as inactive. Alternatively, the terminal may configure the unlicensed band secondary cell to a specific state for the license-exempt band. (Or the terminal can configure the corresponding unlicensed frequency band secondary cell) or the terminal can configure the unlicensed frequency band secondary cell to be in an off state.

As described above, a specific state for the license-exempt band may indicate a state in which the terminal according to the present invention can perform a part of normal secondary cell operation or a normal secondary cell operation.

For example, if the base station determines to switch the off state of the corresponding secondary cell, the base station switches the secondary cell to the off state through the above-described physical layer signaling (L1 procedure) do. Or the base station and the terminal recognize the switch-off state of the corresponding secondary cell.

The terminal performs a part of the secondary cell deactivation operation or the secondary cell deactivation operation.

If the base station determines that the corresponding secondary cell is turned on, the base station switches the corresponding secondary cell to the on state through the above-described physical layer signaling (L1 procedure). Or the base station and the terminal recognize that the corresponding secondary cell is turned on.

The terminal performs a part of the secondary cell activation operation or the secondary disablement operation.

As another example (when configuring a license-exempt band cell in the off state), if the base station determines to switch the on state of the corresponding secondary cell, the base station switches the corresponding secondary cell to the on state via the above- mentioned physical layer signaling (L1 procedure) do. Or the base station and the terminal recognize that the corresponding secondary cell is turned on.

The terminal performs a part of the secondary cell activation operation or the secondary activation operation.

Thereafter, when the base station determines to switch the off state of the corresponding secondary cell, the base station switches the corresponding secondary cell to the off state through the above-described physical layer signaling (L1 procedure). Or the base station and the terminal recognize the switch-off state of the corresponding secondary cell.

The terminal performs a part of the secondary cell deactivation operation or the secondary cell deactivation operation.

The secondary cell activation operation or the secondary cell inactivation operation is as described above.

When the small cell is off, the small cell can transmit the cell discovery signal.

The terminal may perform an off state small cell detection and / or an off state small cell radio signal quality based on the cell discovery signal. Alternatively, the terminal may not perform off-state small cell detection and / or off-state small cell measurement based on the cell discovery signal. Alternatively, the terminal can receive information indicating the small cell-on state through the PCell. Alternatively, the terminal can perform an operation (for example, PCell monitoring) for receiving information indicating the small cell on state through the PCell.

When the small cell is in the off state, the operation of the terminal may be performed only when the on-state cell is switched to the off state through the L1 procedure or when the terminal recognizes the off state. It is possible.

Hereinafter, a method of measuring the cell discovery signal received from the small cell in the OFF state in the OFF state briefly described in each of the above-described embodiments will be described in detail.

Cell discovery signal measurement of terminal

Small cell on / off may be provided in a dense mall cell deployment in which small cells are built. When the small cell is turned off, the small cell can transmit the cell discovery signal. Unlike the CRS transmitted every subframe, the cell discovery signal transmitted when the small cell is off is transmitted in a limited subframe.

The base station can provide the terminal with the necessary information to perform small cell discovery or to perform cell discovery signal based channel condition measurements. For example, the base station may transmit measurement configuration information for measuring the cell discovery signal to the terminal. The measurement configuration information may at least include timing related information of the cell discovery signal (s). As an example, the measurement configuration information may include information on the period of the cell discovery signal. As another example, the measurement configuration information may include cell discovery signal offset information indicating a first sub-frame in which each cell discovery signal occurs in one SFN (or a radio frame or a specific SFN number). As another example, the measurement configuration information may include duration information in which reception of the cell discovery signal is continued. As another example, the measurement configuration information may include timer information that terminates performing cell discovery signal based measurements.

In order to detect / detect a cell based on a cell discovery signal transmitted in a limited subframe or to measure a channel state, the UE acquires a downlink synchronization signal of the corresponding cell to obtain a first measurement sample, and a cell discovery signal The cell can be remeasured according to the pattern (or period) to be transmitted. The synchronization signal of the small cell and the cell discovery signal set to the off state may be transmitted in one subframe. Alternatively, the synchronization signal and the cell discovery signal of the small cell set to the off state may be transmitted with a constant subframe interval. Or the synchronization signal and the cell discovery signal may be transmitted on specific subframes in a particular radio frame of the small cell set to the off state.

Different small cells may have different cell discovery signal periods or patterns. When a small cell is constructed in a dense manner or a plurality of small cells are constructed, the terminal can perform cell discovery signal measurement for different small cells in an off state. When the UE performs measurements on all received cell discovery signals according to the cell discovery signal cycle or pattern of each small cell in order to perform cell discovery signal measurement on different small cells, A problem may arise.

Accordingly, the following method can be used as a method for the UE to efficiently perform cell discovery signal measurement on small cells of different sizes.

1) Configure Cell Discovery Signal Measurement Termination Timer

When the small cell is set to the off state, the small cell can transmit the cell discovery signal.

The terminal can perform the cell discovery signal based measurement through the small cell in the off state.

When configuring a small cell in a terminal (or configuring a cell discovery signal measurement for a small cell supporting on / off function to the terminal, or when configuring a small cell supporting on / (E.g., when configuring small cell discovery and cell discovery signal based measurements on a terminal, or when providing an indication to a terminal indicating a small cell off state, or when a small cell is turned off) You can configure or set up or start a measurement run end timer. The cell discovery signal based measurement execution termination timer may have a different timer value per cell. Or the cell discovery signal based measurement execution end timer may be a terminal-specific timer value.

The cell discovery signal based measurement execution end timer can be configured or started or restarted by the RRC signal. Alternatively, the cell discovery signal based measurement execution end timer may be configured or initiated or restarted by MAC signaling. Alternatively, the cell discovery signal based measurement end timer may be configured or initiated or restarted by L1 signaling (e.g., a physical layer control channel)

The UE can maintain the cell discovery signal based measurement execution end timer for every small cell in the OFF state.

The terminal does not perform the cell discovery signal based measurement when the cell discovery signal based measurement execution end timer expires.

If the cell discovery signal based measurement is performed before the cell discovery signal based measurement execution end timer expires (or if the terminal is provided with an indication indicating the small cell off state, or if information indicating that the small cell is turned off is received ), The UE can restart the cell discovery signal based measurement end timer.

If the small cell is turned on before the cell discovery signal based measurement execution end timer expires, the cell discovery signal based measurement end execution timer may be stopped, released, or expired.

2) Cell discovery signal cycle or pattern in the same base station is configured identically

When the small cell is turned off, the small cell can transmit the cell discovery signal.

When configuring a small cell in a terminal (or configuring a cell discovery signal measurement for a small cell supporting on / off function to the terminal, or when configuring a small cell supporting on / When a small cell discovery and a cell discovery signal based measurement are configured in a terminal or when an indication indicating a small cell off state is provided to a terminal or when a small cell is switched to an off state) And may provide the necessary information to perform cell discovery or to perform cell discovery signal based measurements.

In order to reduce the power consumption of the UE, the BS may determine that the cell discovery signal of all or some of the cells included in the cell group associated with the BS, or the cells provided by one BS, or all or some of the cells controlled by the same BS scheduler, As shown in FIG.

For example, the cell discovery signal transmission period or pattern of the cells in the base station having different frequencies may be transmitted equally, and the terminal may perform cell discovery signal measurement for each cell in the off state in the same subframe.

Another example is to transmit the cell discovery signal transmission period or pattern of the cells in the base station having the same frequency equally, but by setting a certain offset value to the cell discovery signal transmission of each cell, And to perform cell discovery signal measurement for each cell.

As another example, a cell discovery signal transmission period or pattern of cells in the base station belonging to the same timing advance group may be equally transmitted, and the terminal may perform cell discovery signal measurement for each cell in the off state in the same subframe .

Another example is to transmit the cell discovery signal transmission period or pattern of the cells in the base station belonging to the same timing advance group equally and to set the cell discovery signal transmission of each cell to have a constant offset value, , And to perform cell discovery signal measurement for each cell in the OFF state.

In another example, the base station may configure the terminal with a cell discovery signal transmission period or pattern of the same cell group or the same timing advance group unit.

In another example, the base station may configure the cell discovery signal transmission period or pattern on a cell group or a timing advance group basis for different cell groups or different timing advance groups, It is also possible to configure the terminal with different offset values for the signal transmission period or pattern.

3) Cell discovery signal cycle or pattern is configured differently depending on cell state, or cell discovery signal transmission cycle and cell discovery signal measurement cycle are configured differently

When the small cell is turned off, the small cell can transmit the cell discovery signal.

When configuring a small cell in a terminal (or configuring a cell discovery signal measurement for a small cell supporting on / off function to the terminal, or when configuring a small cell supporting on / When a small cell discovery and a cell discovery signal based measurement are configured in a terminal or when an indication indicating a small cell off state is provided to a terminal or when a small cell is switched to an off state) And may provide the terminal with the necessary information to perform cell discovery or to perform cell discovery signal based measurements.

In order to reduce the power consumption of the UE, the BS may configure the cell discovery signal transmission period or pattern differently depending on the cell state.

For example, the UE can perform measurement based on the CRS transmitted in every subframe in the ON state. Therefore, the base station does not transmit the cell discovery signal in the ON state of the small cell, or can transmit the cell discovery signal in a longer transmission period or pattern than the OFF state.

As another example, the base station may transmit the cell discovery signal in a specific cell discovery signal transmission period or pattern regardless of the on / off state of the small cell (or for the off state small cell). When the small cell is in the off state, the base station can transmit information to the mobile station so that measurement or reporting can be performed in a longer period than in the ON state. The terminal can use this to perform cell discovery signal based measurement or reporting in a longer period.

As another example, when the small cell is configured in the terminal even in the off state, the terminal may need to perform measurement with a longer period or a shorter period than when the small cell is not configured in the terminal. For example, when the small cell frequency in the off state is different from the frequency of the serving cell (s) configured in the current terminal, the base station determines that the intra-frequency measurement based on the cell discovery signal in the state where the off- The small cell can be performed in a shorter cycle or a longer cycle as compared with the inter-frequency measurement based on an unconfigured cell discovery signal. Therefore, when the small cell in the off state is configured in one or more terminals, the base station can set the cell discovery signal transmission period or pattern to a shorter transmission period or pattern than when the small cell in the off state is not configured in any terminal . The base station can transmit indication information to the terminal, and the terminal can perform measurement based on the cell discovery signal.

As another example, when the small cell is configured in the terminal even in the off state, the terminal may need to perform measurement with a longer period or a shorter period than when the small cell is not configured in the terminal. For example, when the small cell frequency in the off state is different from the frequency of the serving cell (s) configured in the current terminal, the base station sets the cell discovery signal based intra-frequency measurement in the off- It is possible to control the cell to perform with a shorter period or a longer period as compared to an unconfigured cell discovery signal based inter-frequency measurement. However, the base station can transmit the cell discovery signal in a specific cell discovery signal transmission period or pattern regardless of whether the small cell is configured in more than one terminal in the off state (or regardless of the state of the small cell). The base station can transmit configuration / indication information for causing the terminal to perform measurement or reporting in a shorter period or longer period depending on the state in which the off-state small cell is configured in the terminal. The terminal can use this to perform cell discovery signal based measurements in shorter or longer periods.

As another example, if the small cell is configured to be in an active state even if the small cell is in the off state, the terminal needs to perform measurement with a longer period or a shorter period than when the small cell is configured to be in the inactive state Can be. Therefore, when the small cell is activated to one or more terminals in the off state, the base station can set the cell discovery signal transmission period or pattern to a shorter period or pattern than when the small cell in the off state is not activated to any terminal. Meanwhile, the base station may transmit the configuration information or the indication information for the period or pattern of the cell discovery signal to the terminal, and the terminal may perform the cell discovery signal based measurement using the configuration information or the display information.

As another example, when the small cell is activated in the terminal even when the small cell is in the off state, the terminal needs to perform the cell discovery signal measurement with a longer period or a shorter period than when the small cell is not activated . However, the base station can transmit the cell discovery signal in a specific cell discovery signal transmission period or pattern irrespective of whether the small cell is activated to one or more terminals in the off state or regardless of the state of the small cell. The base station may transmit configuration or indication information for causing the terminal to perform a longer period or shorter period measurement or reporting according to the status of the off-state small cell, and the terminal may use the configuration or display information to measure the cell discovery signal- May be performed with a shorter period or a longer period.

In another example, the small cell may be in the off state, allowing the terminal to perform the measurement or reporting at a longer period than the specific cell discovery signal transmission period or pattern transmitted via the off state small cell. The base station can transmit the cell discovery signal transmission period or pattern of the off-state small cell to the terminal in addition to the information for performing measurement or reporting with a longer period of time in which the cell discovery signal based measurement can be performed for each terminal have. The terminal can perform the cell discovery signal based measurement using the above-described information in a longer period than the cell discovery signal transmission period or the pattern.

The base station may also be configured to distribute the cell discovery signal-based measurement period performed for each UE within the cell discovery signal transmission period.

For example, when the cell discovery signal transmission period is T_Period and the cell discovery signal measurement period of the UE is M_Period, M_Period = n * T_Period, n can be a natural number. Specifically, when M = Period = 2 * T_Period, the measurement periods are distributed to the terminal groups of the odd number T_Period (1, 3, 5, ...) and the even terminal T_Period (2, 4, 6, Therefore, when M_Period = n * T_Period, the measurement period can be distributed to a maximum of n groups.

In one example, the cell discovery signal transmission period described above may be timing related information of the discovery signal (s) required to perform small cell discovery or to perform cell discovery signal based measurement. For example, the above-described cell discovery signal pattern may include a cell discovery signal offset indicating a first sub-frame in which each cell discovery signal is generated in one SFN (or a radio frame or a specific SFN number), and / And may include persistent duration information.

As another example, the above-described cell discovery signal measurement period may be measurement gap information for inter-frequency measurement based on the cell discovery signal when the frequency of the off-state small-cell is different from the frequency of the serving cell (s) currently configured in the terminal. In the prior art, the measurement gap is a value configured to be terminal specific. In this case, for the inter-frequency or inter-RAT measurement of the UE, the BS does not perform scheduling for uplink or downlink transmission to the UE in the measurement gap. If the measurement gaps of all terminals in a particular cell are the same, there may be a problem that resources in the measurement gap can not be used. Therefore, the conventional measurement gap can be dispersed for each UE through a gap offset value in the measurement gap period.

The cell discovery signal transmission period or pattern in the small cell in the OFF state can be fixed on a cell-by-cell basis. When there are a plurality of off-state small cells, the cell discovery signal transmission period or pattern between cells may be the same or different. If all terminals have the same measurement gap in order to measure the off-state small cell (s) based on the cell discovery signal, it may be inefficient because resources in that measurement gap can not be used. In addition, the power consumption of the UE can be increased by measuring the cell discovery signal in every cell discovery signal transmission period or pattern. This problem may occur more severely if the DRX is configured and the terminal is in an inactive state. If the cell discovery signal measurement period and the cell discovery signal transmission period are used for each terminal group, the measurement gap can be divided into n terminal groups.

For example, if the cell discovery signal transmission period is 10 ms, the gap offset period may be selected within four values (for example, 0, 10, 20, 30) when the period of the measurement gap is 40 ms . If the cell discovery signal transmission period is 40 ms, the gap offset value can be selected within two values (for example, 0, 40) when the measurement gap period is 80 ms.

In another example, the above-described cell discovery signal measurement period may be measurement cycle information for secondary cell measurement based on the cell discovery signal when the small cell in the OFF state is configured in the UE and the small cell in the OFF state is the serving cell. For example, the measurement cycle information for the secondary cell measurement based on the cell discovery signal may be included as a new information element (e.g. MeasCycleOffSCell-r12 or MeasCycleDRS-r12) in the MeasObjectEUTRA field included in the measurement configuration or measurement configuration. The measurement cycle information for the secondary cell measurement based on the cell discovery signal may have a value longer than the cell discovery signal transmission period (for example, n times of the DRS transmission period and n is an integer). Or the measurement cycle information for the secondary cell measurement based on the cell discovery signal may have the same value as the measurement cycle information value for the secondary cell measurement in the inactive state in the existing standard. For example, if the cell discovery signal transmission period is 10 ms, the measurement cycle information for the secondary cell measurement based on the cell discovery signal may be selected from one or more of sf160, sf320, sf640, and sf1280. For another example, if the transmission period is 40 ms, the measurement cycle information for the secondary cell measurement based on the cell discovery signal may be selected from one or more of sf160, sf320, sf640, sf1280.

The method of distributing the cell discovery signal measurement period of the inter-frequency measurement gap per terminal or the intra-frequency measurement cycle of n times the transmission period is not limited to the illustrated example.

The above-described methods described herein can be used independently or in combination of one or more methods.

Cell Discovery Signal Measurements CRS  Measurement and Reporting

When the small cell is turned off, the small cell can transmit the cell discovery signal. When the small cell is turned on, the small cell may not transmit the cell discovery signal.

Alternatively, when the small cell is turned off, the small cell can transmit the cell discovery signal. When the small cell is turned on, the small cell can transmit the cell discovery signal.

For example, if the cell transmits a cell discovery signal when the small cell is on, and the terminal is configured for cell discovery signal measurement and CRS measurement, the terminal can perform both cell discovery signal based measurement and CRS based measurement. In addition, the terminal can perform both cell discovery signal based measurement reporting and CRS based measurement reporting. Alternatively, the terminal may only perform measurement reporting of either cell discovery signal based measurement reporting or CRS based measurement reporting. This can be determined either by the terminal itself or by the base station when it configures the measurement.

As another example, if a small cell is transmitting a cell discovery signal and the terminal is configured for cell discovery signal measurement and CRS measurement, the terminal performs only one of the cell discovery signal based measurement and the CRS based measurement can do. This can be determined by the terminal itself or by the base station to configure the measurement to be prioritized.

As described above, the present invention provides an effect of efficiently performing RRM measurement based on a cell discovery signal transmitted only in a limited subframe and reporting it to a base station, thereby reducing power consumption of the UE do. In addition, the present invention provides an effect of preventing cell-to-cell signal interference and wasted power consumption of the entire system by adding a cell supporting on / off function of the terminal as a secondary cell in an environment in which a plurality of small cells are deployed. In addition, the present invention defines an activation or deactivation operation method of a secondary cell when a terminal supporting ON / OFF function is added, thereby preventing the ambiguity of the activation operation of the cell supporting the ON / OFF function to provide. In addition, the present invention provides a concrete method of transmitting and receiving data as needed in parallel with the on / off operation and the activation operation, thereby providing an effect of processing a large amount of data at a high speed.

The configuration of a terminal and a base station to which all of the above-described present invention can be performed will be described again with reference to the drawings.

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

9, a user terminal 900 according to another embodiment of the present invention includes a receiver 930, a controller 910, and a transmitter 920.

The terminal 900 of the present invention includes a receiver 930 for receiving measurement configuration information for measuring a cell discovery signal, a transmitter for transmitting measurement configuration information and radio signal quality measurement information of a measured cell based on the cell discovery signal 920), and a controller 910 that further configures a cell associated with the cell discovery signal as a secondary cell based on the upper layer signal.

The receiving unit 930 may receive a physical layer signal including information indicating whether the secondary cell is activated. In addition, the controller 910 can control activation or deactivation of the terminal for the secondary cell based on the physical layer signal. For example, when the physical layer signal includes information indicating the on state of the secondary cell, the controller 910 can control the secondary cell activation or the secondary cell activation of the terminal for the secondary cell to be performed have. In this case, the secondary cell activation operation may include at least one of an upward reference signal transmission operation on the secondary cell, a channel state information reporting transmission operation for the secondary cell, a control channel monitoring operation on the secondary cell, and a control channel monitoring operation for the secondary cell .

In addition, when the physical layer signal includes information indicating the off state of the secondary cell, the controller 910 can control the partial deactivation operation or the secondary deactivation operation of the terminal for the secondary cell to be performed. The secondary cell deactivation operation does not transmit the uplink reference signal on the secondary cell, does not transmit the uplink shared channel on the secondary cell, does not transmit the random access channel on the secondary cell, reports channel state information on the secondary cell The control channel is not monitored on the secondary cell, and the control channel is not monitored on the secondary cell. .

In addition, the controller 910 can control the terminal operation for operating the above-described embodiments of the present invention.

The receiving unit 930 receives downlink control information, data, and a message from the base station through the corresponding channel. The transmitter 920 transmits uplink control information, data, and a message to the base station through the corresponding channel.

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

10, a base station 1000 according to another embodiment of the present invention includes a control unit 1010, a transmission unit 1020, and a reception unit 1030.

The base station 1000 of the present invention includes a receiver 1030 for receiving measurement configuration information for measuring a cell discovery signal and radio signal quality measurement information of a cell associated with a measured cell discovery signal based on a cell discovery signal, And a transmitter 1020 for transmitting an upper layer signal including information for controlling the terminal to additionally configure a cell associated with the secondary cell.

In addition, the transmitter 1020 may transmit a physical layer signal including information indicating an on state or an off state of the secondary cell. For example, the physical layer signal including the information indicating the on state of the secondary cell may be generated by the terminal receiving the physical layer signal to perform a part of the secondary cell activation operation or the secondary cell activation operation of the terminal for the secondary cell . Alternatively, the physical layer signal including the information indicating the off state of the secondary cell may be generated by controlling the terminal receiving the physical layer signal to perform a part of the secondary cell deactivation operation or the secondary cell deactivation operation of the terminal for the secondary cell .

The transmitting unit 1020 may transmit measurement configuration information including information necessary for measurement and retrieval of the cell discovery signal.

The controller 1010 controls the on / off state of the small cell required for performing the above-described present invention, the generation of a signal to be transmitted to the terminal, and the overall operation of the base station necessary to perform each of the above embodiments .

In addition, the transmitting unit 1020 and the receiving unit 1030 are used for transmitting / receiving signals, messages, and data necessary for performing the above-described present invention to / from the terminal.

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 (20)

A method for a terminal to control a secondary cell operation,
Receiving measurement configuration information for measuring a cell discovery signal;
Transmitting measurement configuration information of the measured cell based on the measurement configuration information and the cell discovery signal; And
Further comprising configuring cells associated with the cell discovery signal as secondary cells based on an upper layer signal. The method according to claim 1,
Receiving a physical layer signal including information indicating an on state or an off state of the secondary cell; And
And controlling an activation or deactivation operation of the terminal for the secondary cell based on the physical layer signal. 3. The method of claim 2,
When the physical layer signal includes information indicating an on state of the secondary cell,
A method of performing control so that a part of the secondary cell activation operation or the secondary cell activation operation of the terminal with respect to the secondary cell is performed The method of claim 3,
The secondary cell activating operation includes:
(SRS) transmission operation on the secondary cell, a channel state information (CSI) reporting transmission operation for the secondary cell, a control channel monitoring operation on the secondary cell, and a control channel for the secondary cell Wherein the at least one monitoring operation comprises one or more operations. 3. The method of claim 2,
When the physical layer signal includes information indicating an off state of the secondary cell,
A part of the terminal deactivation operation or the secondary inactivation operation for the secondary cell is performed. 6. The method of claim 5,
The secondary cell deactivation operation includes:
(SRS) is not transmitted on a secondary cell, an uplink shared channel is not transmitted on a secondary cell, a random access channel is not transmitted on a secondary cell, channel state information is transmitted for a secondary cell, CSI) reporting, control channel non-monitoring on a secondary cell, and control channel non-monitoring for a secondary cell. A method for a base station to control a secondary cell operation of a terminal,
Receiving measurement configuration information for measuring a cell discovery signal and measurement information of a cell associated with the cell discovery signal measured based on the cell discovery signal; And
And transmitting an upper layer signal including information for controlling the cell to add a cell associated with the cell discovery signal to the secondary cell. 8. The method of claim 7,
Further comprising transmitting a physical layer signal including information indicating whether the secondary cell is on or off. 9. The method of claim 8,
The physical layer signal includes:
And information indicating the on state of the secondary cell for controlling the terminal receiving the physical layer signal to perform a part of the secondary cell activation operation or the secondary cell activation operation of the terminal for the secondary cell. 9. The method of claim 8,
The physical layer signal includes:
And information indicating an off state of the secondary cell for controlling the terminal receiving the physical layer signal to perform a part of the secondary cell deactivation operation or the secondary deactivation operation of the terminal for the secondary cell. In a terminal for controlling a secondary cell operation,
A receiving unit for receiving measurement configuration information for measuring a cell discovery signal;
A measurement unit configured to measure measurement information of a cell based on the measurement configuration information and the cell discovery signal; And
And a control unit configured to further configure a cell associated with the cell discovery signal as a secondary cell based on the upper layer signal. 12. The method of claim 11,
The receiver may further comprise:
Further receiving a physical layer signal including information indicating an on state or an off state of the secondary cell,
Wherein,
And controls an activation or deactivation operation of the terminal for the secondary cell based on the physical layer signal. 13. The method of claim 12,
Wherein,
When the physical layer signal includes information indicating an on state of the secondary cell,
The secondary cell activation operation or the secondary cell activation operation of the terminal with respect to the secondary cell is performed. 14. The method of claim 13,
The secondary cell activating operation includes:
(SRS) transmission operation on a secondary cell, a channel state information (CSI) reporting transmission operation for a secondary cell, a control channel monitoring operation on a secondary cell, and a control channel monitoring for a secondary cell A terminal comprising one or more operations in operation. 13. The method of claim 12,
Wherein,
When the physical layer signal includes information indicating an off state of the secondary cell,
Wherein the control unit controls the terminal to perform a deactivation operation or a secondary deactivation operation for the secondary cell. 16. The method of claim 15,
The secondary cell deactivation operation includes:
(SRS) is not transmitted on the secondary cell, the uplink shared channel is not transmitted on the secondary cell, the random access channel is not transmitted on the secondary cell, and the channel state information for the secondary cell (CSI: Channel State Information) reporting, a control channel non-monitoring on a secondary cell, and a control channel non-monitoring for a secondary cell. A base station for controlling a secondary cell operation of a terminal,
A receiving unit for receiving measurement configuration information for measuring a cell discovery signal and measurement information of a cell associated with the cell discovery signal measured based on the cell discovery signal; And
And a transmitter for transmitting an upper layer signal including information for controlling the terminal to additionally configure a cell associated with the cell discovery signal as a secondary cell. 18. The method of claim 17,
The transmitter may further comprise:
Wherein the base station further transmits a physical layer signal including information indicating an on state or an off state of the secondary cell. 19. The method of claim 18,
The physical layer signal includes:
Wherein the information indicating the ON state of the secondary cell for controlling the terminal receiving the physical layer signal to perform a part of the secondary cell activation operation or the secondary cell activation operation of the terminal for the secondary cell. 19. The method of claim 18,
The physical layer signal includes:
And information indicating an off state of the secondary cell to control the terminal, which has received the physical layer signal, to perform a part of the secondary cell deactivation operation or the secondary deactivation operation of the terminal for the secondary cell.

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