KR20150083784A - Methods for receiving a reference signal for small cell discovery and Apparatuses thereof - Google Patents

Abstract

The present invention relates to a method for transmitting and receiving a reference signal for small cell discovery. More specifically, the present invention relates to a method for setting a downlink reference signal used by a terminal to search a small cell base station in a deactivated state. Particularly, the present invention provides: a method of a terminal for receiving a reference signal for small cell discovery; and an apparatus for the same. The method includes the steps of: receiving a reference signal transmitted by a base station in a deactivated state; and checking the reference signal by using transmission antenna port information and wireless resource allocation information of the reference signal.

Description

TECHNICAL FIELD [0001] The present invention relates to a method for receiving a reference signal for small cell discovery,

The present invention relates to a method for transmitting and receiving a reference signal for small cell discovery. More particularly, the present invention relates to a method of setting a downlink reference signal for searching for a small cell base station in a disabled state.

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

On the other hand, according to the increase of the wireless terminal and the increase of the transmission / reception data, the communication system needs to process a large amount of data. Accordingly, various types of base stations for data processing have been developed, and the increase of such base stations or data transmission / reception points causes an increase in power consumption of the entire communication system. In addition, when a large number of base stations are located in a dense environment for processing a large amount of data, a radio signal transmitted / received by each base station is increased, resulting in a signal interference phenomenon, which lowers data processing speed.

SUMMARY OF THE INVENTION The present invention, which is devised in accordance with the above-described needs, proposes a method and apparatus for transmitting and receiving a reference signal of a base station performing on / off operation in a small cell deployment environment in which macro cells and small cells are overlapped.

Also, the present invention proposes an antenna port and a radio resource setting method and apparatus for transmitting a reference signal for small cell discovery by a base station in an inactive (OFF) state.

Also, the present invention proposes a method and apparatus for transmitting and receiving a reference signal for small cell discovery in order to minimize signal interference in a small cell deployment situation.

According to an aspect of the present invention, there is provided a method of receiving a reference signal for small cell discovery, the method comprising: receiving a reference signal transmitted by a base station in an inactive state; And identifying the reference signal using the allocation information.

According to another aspect of the present invention, there is provided a method of transmitting a reference signal for small cell discovery, the method comprising: configuring a base station into a deactivated state; generating a reference signal by setting transmission antenna port information and radio resource allocation information; And transmitting a reference signal using the antenna port information and the radio resource allocation information.

According to another aspect of the present invention, there is provided a terminal for receiving a reference signal for small cell discovery, the terminal including a receiving unit for receiving a reference signal transmitted by a base station in an inactive state, And a control unit for confirming the terminal apparatus.

According to another aspect of the present invention, there is provided a base station for transmitting a reference signal for small cell discovery, the base station including a controller configured to configure a base station to be inactive, generate transmit antenna port information and radio resource allocation information to generate a reference signal, And a transmitter for transmitting a reference signal using the radio resource allocation information.

The present invention described above provides an effect of reducing signal interference by changing a base station providing a small cell to an inactive state in an environment in which macro cells and small cells overlap.

The present invention also provides a specific procedure and method for the terminal to receive and verify a reference signal transmitted by a base station in an inactive state.

The present invention also relates to a method and apparatus for measuring a channel state of a base station in a non-active state by receiving a reference signal and performing connection with a base station in an inactive state based thereon, thereby reducing power consumption and signal interference of the communication system, And provides an effect that can be processed.

1 is a view showing a small cell development according to an embodiment.
2 is a diagram showing a small cell deployment scenario.
3 to 6 are diagrams showing detailed scenarios in the small cell deployment.
7 is a diagram illustrating an example of radio resource allocation of a downlink reference signal.
8 is a diagram showing an example of information elements of measurement configuration information.
9 is a diagram illustrating an example of an information element of an RRC connection reconfiguration message with upper layer signaling according to the present invention.
10 is a diagram illustrating an example of information elements of upper layer signaling including configuration information for CSI-RS transmission.
11 is a diagram illustrating another example of information elements of upper layer signaling including configuration information for CSI-RS transmission.
12 is a diagram illustrating a CSI-RS transmit antenna port table according to an embodiment of the present invention.
13 is a diagram illustrating a CSI-RS transmit antenna port table according to the number of transmit antenna ports according to another embodiment of the present invention.
FIG. 14 is a diagram illustrating an example of a radio resource configuration table for CSI-RS transmission for each frame structure type in the case of the normal cyclic prefix.
FIG. 15 is a diagram illustrating an example of a radio resource configuration table for CSI-RS transmission for each frame structure type in the case of an extended cyclic prefix.
16 is a diagram for explaining operations of a terminal according to another embodiment of the present invention.
17 is a view for explaining the operation of a base station according to another embodiment of the present invention.
18 is a diagram illustrating a configuration of a user terminal according to another embodiment of the present invention.
19 is a diagram illustrating a configuration of a base station according to another embodiment of the present invention.

Hereinafter, some embodiments of the present invention will be described in detail with reference to exemplary drawings. It should be noted that, in adding reference numerals to the constituent elements of the drawings, the same constituent elements are denoted by the same reference 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, OFDM- 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.

In this specification, the macro cell and the small cell are classified by the relative size of the coverage of the communicable cell, and the macro cell has a wider coverage than the small cell. A macro cell and a small cell may be formed by respective base stations or transmission / reception points. In this specification, a base station providing a macro cell is referred to as a macro cell base station, a master base station or a MeNB, and a base station for providing a small cell A small cell base station, a secondary base station, or a SeNB. In this specification, it is assumed that the base station that changes states into the ON state and the OFF state is referred to as a base station providing a small cell, but the present invention is not limited thereto.

The present invention proposes a method of establishing a downlink reference signal for detecting an arbitrary cell formed by an arbitrary base station (eNB, RRH or RU) in a 3GPP LTE or LTE-Advanced wireless mobile communication system . In particular, as a method for reducing power consumption of a base station (eNB or RRH or RU) and reducing interference to a neighboring cell, a corresponding cell is turned on or deactivated according to the number of terminals belonging to the cell or the amount of data traffic a semi-static or dynamic cell on / off mechanism is provided to turn off the cell. In order to achieve this, a CSI-RS transmission method for cell discovery is proposed when the CSI-RS is newly used as a downlink reference signal for cell discovery in addition to the existing PSS / SSS and CRS.

In this regard, in the present invention, in particular, semi-static or dynamic small cell omnidirections in various types of small cell base stations (eNBs or RRHs or RUs) formed by overlapping macro cells, And a method of setting a small cell detection / discovery reference signal according to application of a dynamic small cell on / off will be described. However, it is apparent that the present invention can be applied not only to small cells but also to cells of various sizes and various types.

In a 3GPP LTE or LTE-Advanced system, a macro cell formed by a high power base station (eNB), a Coordinated MultiPoint (CoMP) system with a small cell formed by a low power RRH connected to a high- ) Various techniques for applying the technology can be defined. In addition, a heterogeneous network scenario in which a pico cell or a micro cell for supporting a hot spot or a coverage hole is formed by overlapping a macro cell, Various interference control techniques can be proposed. In addition, various communication methods using the small cell are being studied.

Hereinafter, a small cell deployment scenario to which the present invention is applicable will be described.

1 is a view showing a small cell development according to an embodiment.

FIG. 1 shows a configuration in which a small cell and a macro cell coexist. In FIGS. 2 to 3, the presence or absence of macro coverage, whether the small cell is for outdoor use or indoor use, , Whether the development of the small cell is sparse or dense, or whether the same frequency spectrum as the macro is used in terms of spectrum or not.

2 is a diagram showing a small cell deployment scenario. Figure 2 shows a typical representative configuration for the scenario of Figure 3; Fig. 2 shows a small cell deployment scenario and includes scenarios # 1, # 2a, # 2b, and # 3. 200 represents a macro cell, and 210 and 220 represent a small cell. The overlapping macrocells in FIG. 2 may or may not exist. Coordination can be performed between the macro cell 200 and the small cells 210 and 220 and adjustment can also be performed between the small cells 210 and 220. And the overlapping regions of 200, 210, and 220 can be clustered.

3 to 6 are diagrams showing detailed scenarios in the small cell deployment.

Fig. 3 shows scenario # 1 in the small cell expansion. Scenario 1 is a co-channel deployment scenario for small cells and macro cells in the presence of overhead macros and is an outdoor small cell scenario. Reference numeral 310 denotes a case where both the macro cell 311 and the small cell are outdoors, and 312 denotes a small cell cluster. Users are distributed both indoors / outdoors.

The solid lines connecting the small cells in the small cell 312 mean a backhaul link within a cluster. The dotted lines connecting the base station of the macro cell and the small cells in the cluster mean a backhaul link between small cells and macro cells.

Fig. 4 shows the small cell deployment scenario # 2a. Scenario 2a is a deployment scenario in which small cells and macros use different frequency spectra in the presence of an overlaid macro, and is an outdoor small cell scenario. Both the macro cell 411 and the small cells are outdoors and 412 indicates a small cell cluster. Users are distributed both indoors / outdoors.

The solid lines connecting the small cells in the small cell 412 indicate a backhaul link within the cluster. The dotted lines connecting the base station of the macro cell and the small cells in the cluster mean a backhaul link between small cells and macro cells.

5 shows the small cell deployment scenario # 2b. Scenario 2b is a deployment scenario in which the small cell and the macro use different frequency spectrum in the presence of the overlay macro and is an indoor small cell scenario. The macro cell 511 is outdoors, the small cells are all indoors, and 512 is a small cell cluster. Users are distributed both indoors / outdoors.

The solid lines connecting the small cells in the small cell 512 indicate a backhaul link within the cluster. The dotted lines connecting the base station of the macro cell and the small cells in the cluster mean a backhaul link between small cells and macro cells.

6 shows the small cell deployment scenario # 3. Scenario 3 is an indoor small cell scenario with no coverage of macros. 612 indicates a small cell cluster. In addition, the small cells are all indoor and users are dispersed both indoors and outdoors.

The solid lines connecting the small cells in the small cell 612 mean a backhaul link within the cluster. The dotted lines connecting the base station of the macro cell and the small cells in the cluster mean a backhaul link between small cells and macro cells.

The frequencies F1 and F2 used in the various small cell scenarios of FIGS. 1 and 2 to 6 described above may be frequencies that support the same duplex mode, or F1 and F2 may have different duplex modes , For example, F1 may be considered to support FDD mode, F2 may be considered to support TDD mode, or vice versa.

< Small cell discovery >

A downlink synchronization for detecting an arbitrary cell formed by an arbitrary base station / an eNB / RU / RRH in a conventional 3GPP LTE / LTE-Advanced system, and a PSS (Primary Synchronization Signal) / SSS (Secondary Synchronization Signal) and CRS (cell specific reference signal). Accordingly, in a base station / eNB / RU / RRH constituting an arbitrary cell, FDD (Frequency Division Duplex) is performed according to a frame structure type (for example, TDD / FDD) SSS through the downlink subframe # 0 and # 5, and transmits the PSS / SSS through the downlink subframe # 1 and # 6 in case of TDD (Time Division Duplex) The CRS is transmitted in the subframe.

However, there is a need for a small cell on / off operation in a small cell deployment scenario, and a discovery procedure related to the small cell on / off operation is required. Therefore, in addition to the PSS / SSS and CRS-based small cell discovery methods, a specific definition of a new small cell discovery procedure based on a new reference signal is required.

When a plurality of small cells are overlapped with any macro cell coverage, overall system throughput is increased through cell splitting gain. However, There are disadvantages such as an interference problem between a small cell and a macro cell which reduces the effect of a gain, an increase in system power consumption and an increase in maintenance cost due to introduction of a plurality of base stations. In particular, even when there is no UE connected in the small cell coverage, the small cell base station / eNB / RU / RRH continuously transmits downlink signals including the PSS / SSS and the PBCH or CRS Therefore, unnecessary power consumption in the small cell base station / eNB / RU / RRH is caused, and unnecessary interference may occur in data transmission / reception in the adjacent cell.

In order to solve this problem, a small cell on / off switch for switching the corresponding small cell base station / eNB / RU / RRH to the inactive mode / state (off mode / state) according to the number of terminals connected to the small cell, / off) operation support. However, when a dynamic or semi-static small cell on / off operation is supported, a cell measurement / discovery procedure of the UE is performed in the corresponding small cell off state. . In addition to the existing PSS / SSS and CRS-based cell measurement / discovery procedures, it is necessary to define CSI-RS or PRS-based cell measurement / discovery methods. In addition, a new discovery RS based cell measurement / discovery procedure needs to be defined.

In the small cell deployment scenario in which the above-described macro cell and a plurality of small cells are superimposed, the number of cells connected to an arbitrary base station / eNB / RRH / RU, the presence or absence of connection terminals, a method and an apparatus for transmitting and receiving a downlink reference signal for small cell discovery to support an on / off operation. In particular, when a conventional CSI-RS is used as a reference signal for small cell discovery, a concrete method and apparatus for antenna port and radio resource allocation for the corresponding CSI-RS transmission will be described.

7 is a diagram illustrating an example of radio resource allocation of a downlink reference signal.

As shown in FIG. 7, in the conventional 3GPP LTE / LTE-Advanced and below systems, mobility (handover) and cell selection / reselection of a UE in a base station / eNB / RU / In order to perform downlink channel measurement of a UE for secondary care cell measurement for mobility management or carrier merging, all downlink subframes Specific reference signal (CRS). However, in the downlink subframe set with the MBSFN subframe, the corresponding CRS is transmitted only through the first OFDM symbol of the first slot or the second OFDM symbol.

That is, referring to FIG. 7, a base station transmitting a CRS maps CRS using different radio resource elements according to the number of antenna ports.

Accordingly, the UE connected to the corresponding base station receives the CRS transmitted through each downlink subframe for a predetermined time and measures the RSRP / RSRQ. The MS reports the measured RSRP / RSRQ result to the BS, and determines whether the MS performs a mobility management procedure such as handover based on the measured RSRP / RSRQ result and a secondary serving cell for merging carriers (Activation / deactivation). The CRS transmitted by the corresponding base station can also be used for channel measurement for determination of a handover target base station and channel measurement for cell selection / reselection of idle state terminals according to movement of a terminal connected to a neighboring base station . Therefore, even if there is no terminal connected to the base station, the base station always transmits the CRS through all the downlink subframes.

However, when a plurality of small cells are overlapped with a macro cell, it is often the case that there is no terminal connected to the small cell. In this case, the downlink signals such as CRS and PSS / SSS or PBCH transmitted from the corresponding small cell may unnecessarily interfere with macro cells or adjacent small cells. In addition, unnecessary power consumption always occurs in the small cell base station / eNB / RU / RRH in order to transmit CRS through each downlink subframe.

In order to solve this problem, a semi-static or dynamic small cell on / off method of changing a small cell to a disabled state when there is no terminal connected to an arbitrary small cell or when there is no data traffic Can be considered. That is, the switching of the on / off mode can be considered dynamically at a subframe level or a 10ms radio frame level for an arbitrary cell. Alternatively, a small cell on / off operation supporting deactivation mode operation that does not perform transmission of the existing downlink PSS / SSS, CRS, or other downlink signals and channels through a quasi-on / off mode switching is considered.

When the small cell on / off operation described above is applied to an arbitrary small cell base station, when the corresponding small cell is in the off state, the CRS for the downlink channel measurement is not transmitted in all downlink subframes Therefore, it is necessary to perform an operation for discovery performance of the terminal for the corresponding small cell. That is, when the small cell base station is in the inactive state, since the downlink signal is not transmitted, the terminal determines whether the terminal is located in the coverage of the inactive small cell base station or information on the channel state of the small cell in the inactive state Can not confirm. Therefore, the inactive small cell base station needs to transmit the downlink reference signal for small cell discovery even in the inactive state. The UE can measure the channel state of the small cell base station in the deactivated state based on the received reference signal and check whether it is located in the coverage of the small cell base station.

In the present invention, a method of transmitting and receiving a downlink reference signal used for a new small cell discovery will be described. In particular, when CSI-RS is used for small cell discovery, the CSI-RS transmission / reception method for small cell discovery will be described. That is, as in the small cell deployment scenario described above, when the small cell operates on different frequency bands from the macrocell and the UE supports the merging of the carriers between the macrocell frequency and the small cell frequency, the CSI-RS setting for the small cell discovery Describe the method.

8 is a diagram showing an example of information elements of measurement configuration information. 9 is a diagram illustrating an example of an information element of an RRC connection reconfiguration message with upper layer signaling according to the present invention.

Referring to FIGS. 8 and 9, according to measurement configuration information for an LTE / LTE-Advanced (E-UTRA) cell included in an RRC connection reconfiguration message as an example of upper layer signaling, The measurement cell list setting information, the measurement gap setting information, and the measurement reporting related setting information are transmitted. In addition, in the RRC connection reconfiguration message related to the secondary cell addition (SCell addition), the corresponding SCellIndex information, cell identification information (PCID, DL carrier frequency) Information related to a radio resource configuration, and the like are transmitted. Specific information areas related to this are shown in FIGS. 8 and 9. FIG.

An antenna port and a radio resource allocation setting method of a downlink reference signal transmitted by a base station (small cell base station) in the inactive state of the present invention will be described with reference to the above description.

First, a method for determining a transmission antenna port of a reference signal will be described.

To be used as a reference signal for discovery CSI - RS  How to set transmit antenna port.

A method for receiving a reference signal for small cell discovery in a terminal according to an embodiment of the present invention includes receiving a reference signal transmitted by a base station in an inactive state, Can be used to confirm the reference signal. Here, the reference signal may be the CSI-RS described above.

 In other words, CSI-RS may be used as a reference signal for discovery / measurement of the deactivation cell, as described above. The CSI-RS may be defined as a new cell discovery / measurement reference signal or may be defined as a cell discovery / measurement reference signal of a corresponding SCell through a RRC connection reconfiguration message for measurement configuration information or SCell addition. When it is defined that CSI-RS can be set as a measurement reference signal, it is necessary to define CSI-RS transmission resources and CSI-RS transmission resources for CSI-RS transmission in the corresponding SCell.

For example, according to the CSI-RS setting method, the number of antenna ports, CSI-RS radio resource setting information, CSI-RS subframe setting information, and the like are transmitted through RRC signaling when setting up a CSI-RS for an arbitrary terminal. RS ports 15, CSI-RS ports 15 and 16, and CSI-RS ports 15 and 16, respectively, according to the number of CSI-RS antenna ports (1,2,4 or 8) 17,18}, and CSI-RS ports {15,16,17,18,19,20,21,22}.

10 is a diagram illustrating an example of information elements of upper layer signaling including configuration information for CSI-RS transmission. 11 is a diagram illustrating another example of information elements of upper layer signaling including configuration information for CSI-RS transmission. Referring to FIG. 10, an information element of an RRC message defined for CSI-RS configuration of 3GPP Rel-10 may be configured as shown in FIG. Referring to FIG. 11, information elements of the RRC message defined for the CSI-RS setting of 3GPP Rel-11 may be configured as shown in FIG. In addition, FIG. 11 may be further defined to additionally set scrambling identification information and QCL-related information for CSI-RS sequence generation. On the other hand, the method defined in the document of 3GPP TS 36.211 can be used for the CSI-RS transmission method using FIG. 10 and FIG.

Hereinafter, an antenna port setting method for CSI-RS transmission when the CSI-RS of the present invention is set as a reference signal for discovery / measurement for a certain SCell will be described. That is, unlike the conventional CSI-RS, a reference signal for discovery or cell measurement transmitted by a base station in an inactive state needs to newly set information on a transmit antenna port. Therefore, a transmission antenna port setting method according to each embodiment will be described.

1st Example : For Discovery  Fixed transmit antenna port for reference signal.

According to an embodiment of the present invention, when a CSI-RS is transmitted as a reference signal for small cell discovery, a fixed antenna port number can be defined to be used. Specifically, the transmit antenna port information confirmed by the UE includes information on a fixed antenna port identification number defined in advance for CSI-RS transmission as a discovery reference signal, and the corresponding fixed antenna port identification number corresponds to a CSI- Or an arbitrary antenna port identification number of 8 antenna ports defined by 15 ~ 22, or may be defined as 2, 4, or 8. That is, when the CSI-RS is set as a reference signal for the cell discovery / measurement in any cell, the transmit antenna port of the corresponding CSI-RS for cell discovery / measurement is defined to use a fixed CSI-RS antenna port .

For example, when CSI-RS is used as a reference signal for small cell discovery, one CSI-RS transmit antenna port can be fixed to a CSI-RS transmit antenna port for the corresponding cell discovery / measurement. Specifically, when CSI-RS is used as a reference signal for discovery for a certain cell, it can always be fixed to transmit the corresponding CSI-RS through the antenna port 15. Or antenna port 16 to the corresponding CSI-RS transmit antenna port, or to define one of the antenna ports 17, 18, 19, 20, 21, 22 as a CSI-RS transmit antenna port for discovery.

As another example, when CSI-RS is used as a reference signal for discovery, it can be defined to be transmitted through a combination of two fixed antenna ports as a CSI-RS transmission antenna port for the corresponding discovery. In this case, the fixed two antenna port combinations are different resource elements such as {15,17}, {16.18}, {15,19}, {17,21}, {19,21}, {20,22} Lt; RTI ID = 0.0 &gt; antenna port &lt; / RTI &gt;

As another example, when CSI-RS is used as a reference signal for discovery, it can be defined to be transmitted through a fixed combination of four antenna ports as a CSI-RS transmission antenna port for the corresponding discovery. In this case, the fixed four antenna port combinations can be fixed to any four antenna port combinations using different resource elements such as {15,17,19,21}, {16,18,20,22} have.

As another example, when CSI-RS is used as a reference signal for discovery, it can be fixed to be transmitted using all eight antenna ports 15 to 22 as a CSI-RS transmission antenna port for the corresponding discovery.

Second Example : For Discovery  Transmit antenna port information for the reference signal.

In another embodiment of the present invention, the UE can receive information on a transmit antenna port set for a reference signal. Information on the transmit antenna port may be received via higher layer signaling. Meanwhile, the transmit antenna port information received through the higher layer signaling may be composed of bitmap information and may be index information indicating an index value of the transmit antenna port table.

Specifically, for example, a base station transmitting a CSI-RS for cell discovery / measurement directly sets a CSI-RS transmission antenna port for a corresponding cell discovery / measurement among the eight CSI-RS antenna ports And transmit it to the terminal through higher layer signaling (e.g., RRC message). In this case, the transmit antenna port information may be included in the above-described measurement configuration or RRC connection reconfiguration message for SCell addition. For example, the CSI-RS transmit antenna port information for the corresponding cell discovery / measurement may be set in a bitmap manner. That is, a bit map composed of 8 bits for 8 antenna port transmission settings is configured for each of the antenna ports 15 to 22, and CSI-RS transmission antenna port information for the corresponding discovery / measurement is transmitted to the terminal can do. As another example, the transmit antenna port information may include a CSI-RS transmission antenna port configuration candidate for each discovery / measurement table in a table mapping manner, a CSI-RS for discovery / measurement to be used in the corresponding cell, Index information indicating a transmit antenna port may be signaled.

12 is a diagram illustrating a CSI-RS transmit antenna port table according to an embodiment of the present invention. The above-described transmission antenna port table can be stored in advance as shown in FIG. However, since FIG. 12 has been described by way of example for the sake of understanding, it is not limited to the specific values of the antenna port and the table configured in each index.

Third Example : For Discovery  Fixed the number of transmit antenna ports for reference signal and transmitted index information according to each port number.

13 is a diagram illustrating a CSI-RS transmit antenna port table according to the number of transmit antenna ports according to another embodiment of the present invention.

In the method for identifying a reference signal by a UE according to another embodiment of the present invention, the transmit antenna port information for reference signal check may indicate an index value of a transmit antenna port table set according to the number of transmit antenna ports stored in advance &Lt; / RTI &gt;

Referring to FIG. 13, the number of CSI-RS transmission antenna ports is fixed, and a CSI-RS transmission antenna port is set based on the number of CSI-RS transmission antenna ports. For example, as shown in FIG. 13, the number of transmit antenna ports for transmitting a reference signal may be set to one, two, four, or eight. 8, the transmit antenna port table may not be needed because all antenna ports are used, and different transmit antenna port tables may be stored in advance according to the number of transmit antenna ports as shown in FIG. That is, the number of CSI-RS transmit antenna ports for cell discovery / measurement may be fixed to 1, fixed to 2 or 4, and index information of the Discovery CSI-RS transmit antenna port table may be transmitted to upper layer signaling . Therefore, the UE can previously store any one of the Tx antenna port tables according to the number of fixed Tx antenna ports in the table of FIG. 13, and transmits the Tx antenna for the reference signal using the index information included in the received Tx antenna port information You can see information about the port.

The transmit antenna port for the reference signal can be set in various manners as described above, and the terminal can confirm the reference signal using the transmit antenna port information.

Hereinafter, a method of setting radio resource element information allocated to a reference signal will be described.

To be used as a reference signal for discovery CSI - RS  Wireless resource allocation method.

A method of setting resources for CSI-RS transmission for the corresponding cell discovery / measurement will be described.

The UE of the present invention can use the radio resource allocation information to which the reference signal is allocated to identify the received reference signal. That is, the CSI-RS signal transmitted by the base station in the deactivated state can be confirmed using information on the radio resource allocation of the CSI-RS for the reference signal. Hereinafter, each embodiment of a method of acquiring radio resource allocation information will be described.

1st Example : Identify radio resource allocation information using cell physical cell identification information and frame structure type.

FIG. 14 is a diagram illustrating an example of a radio resource configuration table for CSI-RS transmission for each frame structure type in the case of the normal cyclic prefix.

FIG. 15 is a diagram illustrating an example of a radio resource configuration table for CSI-RS transmission for each frame structure type in the case of an extended cyclic prefix.

In order to set a general CSI-RS radio resource, CSI-RS transmission antenna ports are classified according to a Cyclic Prefix (CP) length and a frame structure, A resource configuration table for -RS can be configured. FIG. 14 is an example of a resource configuration table configured in the case of the normal cyclic prefix, and FIG. 15 is an example of a resource configuration table configured in the case of the extended cyclic prefix.

Alternatively, a method for implicitly setting CSI-RS transmission radio resource allocation information for cell discovery / measurement will be described in the embodiment of the present invention. For example, the radio resource allocation information may allocate a corresponding CSI-RS transmission radio resource as a function of physical cell identity (PCID) of a cell transmitting the discovery / measurement CSI-RS. For example, in case of a cell of frame structure type 1, the value of the corresponding PCID mod 20 may be defined as a CSI-RS transmission radio resource setting value in case of a normal CP (normal CP). Also, in case of a cell of frame structure type 1, a value of PCID mod 16 may be defined as a CSI-RS transmission radio resource setting value for the corresponding discovery / measurement in case of an extended CP (CP). Similarly, in case of a cell of frame structure type 2, the value of the corresponding PCID mod 32 can be defined as a CSI-RS transmission radio resource setting value for the corresponding discovery / measurement. Also, in case of a cell of frame structure type 2, a value of PCID mod 28 for an extended CP (CP) can be defined as a CSI-RS transmission radio resource setting value for the corresponding discovery / measurement.

Second Example : Identify radio resource allocation information using cell physical cell identification information.

As another example, in the case of the normal CP, regardless of the frame structure type, the value of the corresponding PCID mod 20 is used as the value of the PCID mod 16 for the corresponding discovery / CSI-RS transmission radio resource setting value. That is, unlike the first embodiment, in the second embodiment, the radio resource allocation information can be confirmed only by using the type of the cyclic prefix and the physical cell identification information without considering the frame structure type.

In the case of the first and second embodiments, the UE can receive the physical cell identification information (PCID) of the corresponding cell through higher layer signaling. For example, the upper layer signaling including the physical cell identification information may be a RRConnectionReconfiguration message for the above measurement configuration or SCell addition.

Third Example : Upper layer Signaling  Check the radio resource allocation information through.

The terminal of the present invention may directly receive radio resource allocation information of the reference signal through higher layer signaling. For example, the UE may receive the CSI-RS radio resource allocation information directly in the above-described measurement configuration for SCell addition or RRC connection reconfiguration message for SCell addition.

The UE can directly acquire the radio resource allocation information of the reference signal using the received higher layer signaling.

In the above description, the transmission antenna port setting method and the radio resource allocation method of the reference signal transmitted by the base station configured in the deactivated state have been described by way of each embodiment. Hereinafter, the present invention will be described with reference to operations of a terminal and a base station.

16 is a diagram for explaining operations of a terminal according to another embodiment of the present invention.

In another aspect of the present invention, there is provided a method of receiving a reference signal for small cell discovery, the method comprising: receiving a reference signal transmitted from a base station in an inactive state; And confirming the reference signal using the information.

Referring to FIG. 16, a method for receiving a reference signal for small cell discovery in a mobile station includes receiving a reference signal transmitted by a base station in an inactive state (S1610). That is, the UE can receive a reference signal for cell discovery / measurement transmitted from a base station (a small cell base station) in an inactive state. For example, the reference signal may be a CSI-RS (Channel State Indicator Reference Signal).

Meanwhile, the UE includes a step of checking the reference signal using the transmission antenna port information and the radio resource allocation information of the reference signal (S1620). The UE can use the transmission antenna port information and the radio resource allocation information to which the reference signal is transmitted to check the received reference signal.

For example, the transmit antenna information includes information on a fixed antenna port identification number previously set for transmitting a reference signal, and the fixed antenna port identification number may be set to one, two, four, or eight. That is, the UE can acquire transmission antenna information using a fixed antenna port identification number for transmitting a known reference signal.

As another example, it may receive higher layer signaling including transmit antenna port information. The transmit antenna port information may include bitmap information indicating a transmit antenna port or index information indicating an index value of a predetermined transmit antenna port table. For example, the UE can check the information on the transmit antenna port through the transmit antenna information included in the bitmap scheme for the received higher layer signaling. Alternatively, the UE stores a predetermined transmit antenna port table, and can check information on the transmit antenna port using the index information included in the above-described upper layer signaling.

As another example, the UE may previously store a transmit antenna port table set according to the number of transmit antenna ports, transmit antenna information including index information indicating a specific index value of the transmit antenna port table through upper layer signaling Thereby confirming the information on the transmission antenna.

The upper layer signaling described above may include a measurement configuration or an RRC connection reconfiguration message. In addition, the UE can perform all the operations according to the method of setting the transmit antenna port.

The UE can confirm the reference signal using the radio resource allocation information of the reference signal.

For example, the UE can confirm information on the allocation of radio resources of the reference signal using the Physical Cell IDentity (PCID) of the base station of the radio resource allocation information included in the upper layer signaling. Specifically, the UE can confirm the reference signal based on at least one of the physical cell identification information, the cyclic prefix (CP) type, and the frame structure type. Alternatively, the reference signal can be checked based on the physical cell identification information and the type of the cyclic prefix irrespective of the frame structure type.

As another example, the UE can explicitly check the information on the radio resource allocation using the radio resource allocation information directly included in the upper layer signaling. That is, the UE can receive the upper layer signaling and check the allocation information for the radio resource of the reference signal.

The above-described upper layer signaling may include a measurement configuration or an RRC connection reconfiguration message. In addition, the UE can perform all the operations according to the radio resource setting method described above.

The above-described upper layer signaling including transmission antenna port information or radio resource allocation information may be transmitted from a base station that has made an RRC connection with the UE. That is, since the UE does not make an RRC connection with the base station in an inactive state, a base station that has made an RRC connection with the base station, such as a macro cell base station, transmits transmission antenna port information and radio resource allocation information Lt; / RTI &gt;

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

A method for transmitting a reference signal for small cell discovery in a base station according to another embodiment of the present invention includes configuring a base station into a deactivated state, setting a transmit antenna port information and radio resource allocation information to generate a reference signal And transmitting a reference signal using the transmission antenna port information and the radio resource allocation information.

Referring to FIG. 17, the base station includes a step of configuring the base station into a disabled state (S1710). The inactivation state can be determined according to the number of terminals located in the cell provided by the corresponding base station or the amount of data traffic, and in the case of a small cell base station, the state of the base station is activated or deactivated to reduce power consumption and signal interference Can be changed. The state change may be made at a subframe level or a radio frame level. Thus, the base station can configure the state of the base station to the inactive state when a change to the inactive state is triggered.

The base station includes a step of generating a reference signal by setting transmission antenna port information and radio resource allocation information (S1720). The reference signal is transmitted by the base station in the inactive state as described above, and the terminal can receive the reference signal and perform cell measurement or cell detection. Accordingly, the base station can generate the reference signal by setting the transmission antenna port information for transmitting the reference signal and the radio resource allocation information for allocating the reference signal. The transmit antenna port information includes information on a fixed antenna port identification number set in advance for reference signal transmission, and the fixed antenna port identification number can be set to one, two, four, or eight. Alternatively, the radio resource allocation information may be determined by the Physical Cell IDentity (PCID) of the base station. Or radio resource allocation information may be determined based on at least one of physical cell identification information, a cyclic prefix (CP) type, and a frame structure type.

Here, generating a reference signal means setting a transmission antenna port for transmitting a reference signal and setting a radio resource.

The base station includes a step of transmitting a reference signal using the transmission antenna port information and the radio resource allocation information (S1730). For example, the base station transmits a reference signal using the set transmit antenna port and the radio resource using the set transmit antenna port information and the corresponding radio resource allocation information.

The reference signal may be a CSI-RS (Channel State Indicator Reference Signal).

The present invention described above provides an effect of reducing signal interference by changing the base station providing a small cell to an inactive state in an environment where macro cells and small cells overlap. The present invention also provides a specific procedure and method for the terminal to receive and verify a reference signal transmitted by a base station in an inactive state. The present invention also relates to a method and apparatus for measuring a channel state of a base station in a non-active state by receiving a reference signal and performing connection with a base station in an inactive state based thereon, thereby reducing power consumption and signal interference of the communication system, And provides an effect that can be processed.

A configuration of a terminal and a base station capable of performing all the operations of the present invention will be briefly described.

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

18, a user terminal 1800 according to another embodiment of the present invention includes a receiver 1830, a controller 1810, and a transmitter 1820.

The terminal 1800 that receives the reference signal for small cell discovery according to the present invention includes a receiving unit 1830 that receives a reference signal transmitted by a base station in an inactive state and a transmitting antenna port information and radio resource allocation information And a control unit 1810 for confirming the reference signal. For example, the reference signal may be a CSI-RS (Channel State Indicator Reference Signal).

The receiver 1830 may further receive upper layer signaling including transmit antenna port information or radio resource allocation information. The higher layer signaling may include a measurement configuration or an RRC connection reconfiguration message. In addition, the receiver 1830 receives downlink control information, data, and messages from the base station through the corresponding channel.

The transmitter 1820 transmits uplink control information, data, and a message to the base station through the corresponding channel.

The control unit 1810 confirms the reference signal using the transmission antenna port information and the radio resource allocation information of the reference signal. For example, the transmit antenna information includes information on a fixed antenna port identification number previously set for transmitting a reference signal, and the fixed antenna port identification number may be set to one, two, four, or eight. That is, the control unit 1810 can acquire transmission antenna information using a known fixed antenna port identification number for transmitting a reference signal. As another example, the controller 1810 may check the reference signal using bitmap information indicating a transmit antenna port of the received transmit antenna information or index information indicating an index value of a predetermined transmit antenna port table. As another example, the controller 1810 may check the information on the transmit antennas using the transmit antenna port table set according to the number of previously stored transmit antenna ports and the index information indicating a specific index value of the received transmit antenna port table have.

Also, the control unit 1810 can confirm the reference signal using the radio resource allocation information of the reference signal. For example, the controller 1810 can confirm the information on the allocation of the radio resources of the reference signal using the Physical Cell IDentity (PCID) of the base station of the radio resource allocation information included in the upper layer signaling. Specifically, the UE can confirm the reference signal based on at least one of the physical cell identification information, the cyclic prefix (CP) type, and the frame structure type. Alternatively, the reference signal can be checked based on the physical cell identification information and the type of the cyclic prefix irrespective of the frame structure type. As another example, the controller 1810 can explicitly check the information on the radio resource allocation using the radio resource allocation information directly included in the higher layer signaling. That is, the UE 1800 can receive the upper layer signaling and check the allocation information for the radio resources of the reference signal.

In addition, the control unit 1810 can control the operation of the terminal according to the above-described terminal of the present invention for checking the reference signal using the transmit antenna port information and the radio resource allocation information.

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

19, a base station 1900 according to another embodiment of the present invention includes a receiving unit 1930, a control unit 1910, and a transmitting unit 1920.

The control unit 1910 can configure the base station to be in an inactive state. The inactivation state can be determined according to the number of terminals located in the cell provided by the corresponding base station or the amount of data traffic, and in the case of a small cell base station, the state of the base station is activated or deactivated to reduce power consumption and signal interference Can be changed. The state change may be made at a subframe level or a radio frame level. Accordingly, the control unit 1910 can configure the state of the base station 1900 to be in an inactive state when a change to the inactive state is triggered.

Also, the control unit 1910 can generate the reference signal by setting the transmission antenna port information and the radio resource allocation information. The control unit 1910 may generate reference signals by setting transmission antenna port information for transmitting the reference signals and radio resource allocation information for allocating reference signals. The transmit antenna port information includes information on a fixed antenna port identification number set in advance for reference signal transmission, and the fixed antenna port identification number can be set to one, two, four, or eight. Alternatively, the radio resource allocation information may be determined by the Physical Cell IDentity (PCID) of the base station. Or radio resource allocation information may be determined based on at least one of physical cell identification information, a cyclic prefix (CP) type, and a frame structure type.

In addition, the controller 1910 can control the overall operation of the base station according to the above-described base station of the present invention to generate and transmit the reference signal by setting the transmit antenna port information and the radio resource allocation information.

The transmitter 1920 transmits the reference signal using the transmit antenna port information and the radio resource allocation information. In addition, the transmitter 1920 transmits a reference signal using the set transmission antenna port and the radio resource using the set transmission antenna port information and the corresponding radio resource allocation information. The reference signal may be a CSI-RS (Channel State Indicator Reference Signal). In addition, the transmitter 1920 can transmit downlink signals, data, and messages to the UE.

The receiver 1930 can receive an upper layer signal, data, and a message 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 (24)

A method for a terminal to receive a reference signal for small cell discovery,
Receiving a reference signal transmitted by a base station in an inactive state; And
And checking the reference signal using transmission antenna port information and radio resource allocation information of the reference signal. The method according to claim 1,
The reference signal,
And a CSI-RS (Channel State Indicator Reference Signal). The method according to claim 1,
The transmission antenna port information includes:
Information about a fixed antenna port identification number set in advance for transmission of the reference signal,
Wherein the fixed antenna port identification number is set to any one, two, four, or eight of eight antenna port identification numbers from 15 to 22. The method according to claim 1,
Prior to the step of receiving the reference signal,
Further comprising receiving higher layer signaling including the transmit antenna port information or the radio resource allocation information. 5. The method of claim 4,
The transmission antenna port information includes:
Wherein the index information includes bitmap information indicating a transmit antenna port or index information indicating an index value of a predetermined transmit antenna port table. 5. The method of claim 4,
The transmission antenna port information includes:
And index information indicating an index value of a transmit antenna port table set according to the number of the transmit antenna ports stored in advance. 5. The method of claim 4,
Wherein the radio resource allocation information comprises:
(Physical Cell IDentity, PCID) of the base station,
Wherein the step of verifying the reference signal comprises:
Wherein the reference signal is identified based on at least one of the physical cell identification information, the cyclic prefix (CP) type, and the frame structure type. A method for a base station to transmit a reference signal for small cell discovery,
Configuring the base station to the inactive state;
Transmitting antenna port information and radio resource allocation information to generate the reference signal; And
And transmitting the reference signal using the transmit antenna port information and the radio resource allocation information. 9. The method of claim 8,
The reference signal,
And a CSI-RS (Channel State Indicator Reference Signal). 9. The method of claim 8,
The transmission antenna port information includes:
Information about a fixed antenna port identification number set in advance for transmission of the reference signal,
Wherein the fixed antenna port identification number is set to any one, two, four, or eight of eight antenna port identification numbers from 15 to 22. 9. The method of claim 8,
Wherein the radio resource allocation information comprises:
And the physical cell identity (PCID) of the base station. 12. The method of claim 11,
Wherein the radio resource allocation information comprises:
Wherein the information is determined based on at least one of the physical cell identification information, the cyclic prefix (CP) type, and the frame structure type. A terminal for receiving a reference signal for small cell discovery,
A receiving unit for receiving a reference signal transmitted from a base station in an inactive state; And
And a controller for checking the reference signal using transmission antenna port information and radio resource allocation information of the reference signal. 14. The method of claim 13,
The reference signal,
And a CSI-RS (Channel State Indicator Reference Signal). 14. The method of claim 13,
The transmission antenna port information includes:
Information about a fixed antenna port identification number set in advance for transmission of the reference signal,
Wherein the fixed antenna port identification number is set to any one of 1, 2, 4, or 8 of eight antenna port identification numbers from 15 to 22. 14. The method of claim 13,
The receiver may further comprise:
And further receives an upper layer signaling including the transmission antenna port information or the radio resource allocation information. 17. The method of claim 16,
The transmission antenna port information includes:
Wherein the index information includes bitmap information indicating a transmit antenna port or index information indicating an index value of a predetermined transmit antenna port table. 17. The method of claim 16,
The transmission antenna port information includes:
And index information indicating an index value of the transmit antenna port table set according to the number of the transmit antenna ports stored in advance. 17. The method of claim 16,
Wherein the radio resource allocation information comprises:
(Physical Cell IDentity, PCID) of the base station,
Wherein,
And identifies the reference signal based on at least one of the physical cell identification information, the cyclic prefix (CP) type, and the frame structure type. A base station for transmitting a reference signal for small cell discovery,
The base station is configured to be in the inactive state,
A control unit for generating the reference signal by setting transmission antenna port information and radio resource allocation information; And
And a transmitter for transmitting the reference signal using the transmit antenna port information and the radio resource allocation information. 21. The method of claim 20,
The reference signal,
And a CSI-RS (Channel State Indicator Reference Signal). 21. The method of claim 20,
The transmission antenna port information includes:
Information about a fixed antenna port identification number set in advance for transmission of the reference signal,
Wherein the fixed antenna port identification number is set to one, two, four, or eight arbitrary ones of eight antenna port identification numbers from 15 to 22. 21. The method of claim 20,
Wherein the radio resource allocation information comprises:
And the physical cell identification information (PCID) of the base station. 24. The method of claim 23,
Wherein the radio resource allocation information comprises:
The base station identification information is determined based on at least one of the physical cell identification information, the cyclic prefix (CP) type, and the frame structure type.

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