KR20130087972A - Method for rrm measurement, point and user equipment thereof in coordinated multi-point transmission/reception system - Google Patents

Abstract

The present invention relates to an RRM measurement method, a transmission / reception point thereof, and a terminal in a cooperative multi-cell communication system in which two or more transmission / reception points transmit signals in cooperation.

Description

RRM measurement method and its transmission / reception point and terminal in cooperative multi-cell communication system {Method for RRM Measurement, Point and User Equipment Thereof in Coordinated multi-point transmission / reception system}

The present invention relates to an RRM measurement method, a transmission / reception point thereof, and a terminal in a cooperative multi-cell communication system in which two or more transmission / reception points transmit signals in cooperation.

In a wireless communication system, in order to support wireless communication between a network and a terminal, a terminal must measure and report various information about a channel and a link to a network, and the network generates control information related to access control based on this information. Notify this to the terminal. Through these steps, a connection between the network and the terminal is established.

For the above operation, the network should transmit information on a reference signal to the terminal that the terminal should use for link measurement, and for more effective communication, for example, communication with low feedback / signaling overhead In order to support this, information on the reference signal should be appropriately configured.

It is an object of the present invention to perform RRM measurements as appropriate to support more effective communication.

Another object of the present invention is to support communication with low feedback / signaling overhead.

RRM measurement method of a transmission and reception point according to an embodiment of the present invention in a wireless communication system in which the communication between the two or more transmission and reception points and the terminal, at least one consisting of a carrier (frequency) and bandwidth (bandwidth) and cell ID (cell ID) Transmitting cell list information including cell information and reference signal list information including information on at least one CSI-RS resource to the terminal; And at least one RRM measurement measured through the CSR received based on the cell list information, and at least one measured through CSI-RS received from another transmission / reception point based on the reference signal list information. Receiving a result of the RRM measurement for the specific frequency band obtained from the RRM measurement from the terminal all or includes.

In another embodiment, an RRM measuring method of a terminal includes at least one cell including a frequency, a bandwidth, and a cell ID in a wireless communication system in which two or more transmission / reception points and a terminal cooperate with each other. Receiving reference list information including cell list information including information and information on at least one CSI-RS resource from one transmission / reception point of transmission / reception points; CSI- received from at least one RRM (Radio Resource Management) measurement measured through the CRS received from the one transmit / receive point based on the cell list information and at least one other transmit / receive point based on the reference signal list information Obtaining an RRM measurement result for a specific frequency band from at least one RRM measurement measured through RS; And transmitting all or one of the RRM measurement results to the one transmission / reception point.

A transmission and reception point according to another embodiment may include at least one cell information including a frequency, a bandwidth, and a cell ID in a wireless communication system in which the terminal cooperates with two or more transmission and reception points. At least one RRM (Radio) measured by using a received CSR list information including cell list information and information on at least one CSI-RS resource to the terminal and received based on the cell list information Resource management) Transceiving unit for receiving the RRM measurement results for the specific frequency band obtained from at least one RRM measurement measured through the CSI-RS received from another transmission point based on the measurement and reference signal list information from the terminal; And an operation part for performing a CoMP operation based on the measurement result.

In another embodiment, a terminal includes at least one cell information including a carrier frequency, a bandwidth, and a cell ID in a wireless communication system in which the terminal cooperates with at least two transmission / reception points. Receives reference signal list information including cell list information and information on at least one CSI-RS resource from one transmit / receive point among transmit / receive points, and transmits the following Radio Resource Management (RRM) measurement result to the transmit / receive point. Transmitting and receiving unit; And at least one RRM measurement measured through the CRS received from the one transmission / reception point based on the cell list information, and the measurement through the CSI-RS received from at least one other transmission / reception point based on the reference signal list information. It includes all or part of the measuring unit for obtaining the RRM measurement results for a specific frequency band from at least one RRM measurement.

1 illustrates an example of a wireless communication system to which embodiments are applied.
2 is a flowchart illustrating an RRM measuring method of a first transmission / reception point and a terminal according to another embodiment.
3 shows patterns of the CSI-RS.
4 and 5 are examples of an RRM measurement object configuration.
FIG. 6 is a flowchart illustrating an embodiment of determining RRM measurement information of a UE in step S240 of FIG. 2.
7 shows another example of a wireless communication system to which embodiments are applied.
FIG. 8 is a flowchart illustrating another embodiment of determining RRM measurement information of a UE in step S240 of FIG. 2.
9 is a block diagram illustrating a terminal and a transmission / reception point according to another embodiment.

Hereinafter, some embodiments of the present invention will be described in detail with reference to exemplary drawings. In adding reference numerals to the components of each drawing, it should be noted that the same reference numerals are assigned to the same components as much as possible even though 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.

In the present specification, a cell means a component carrier having a coverage of a signal transmitted from a transmission / reception point or a signal transmitted from a transmission point or a transmission / reception point, and the transmission / reception point itself. Can be.

In the present specification, the network refers to an entire communication network including an entity such as a control terminal for controlling transmission and reception of a first transmission / reception point and other access points and point (s). For example, the network may be configured with one eNB (base station or transmission end, a transmission / reception point) and at least one RRH controlled by the eNB. As another example, the network may include at least one eNB supporting cooperative communication; RRH or at least one eNB and RRH sharing inter-cell interference information or exchanging inter-cell interference. Therefore, the operation of the network described herein may be performed by the first transmission / reception point or may be performed by an entity other than the first transmission / reception point.

In another aspect, in the present specification, the network may refer to an eNB that generates control information for CoMP cooperative communication and may include a first transmission / reception point. The network is not limited to the eNB and may be a higher layer for generating control information. In the following specification, the network and the first transmission / reception point are not distinguished, and collectively referred to as the first transmission / reception point or network as necessary.

1 illustrates a wireless communication system to which embodiments are applied.

Referring to FIG. 1, a wireless communication system 100 to which embodiments are applied includes a coordinated multi-point transmission / reception system (CoMP system) or cooperative system in which two or more transmission / reception points cooperate to transmit a signal. It may be a coordinated multi-antenna transmission system, a cooperative multi-cell communication system. CoMP system 100 may include multiple transmission and reception points and the terminal.

In FIG. 1, the CoMP system 100 includes two or more transmission / reception points designed to have the same PCID (Physical Cell ID) for the same frequency band.

The multiple transmit / receive points may include at least one having a high transmit power or a low transmit power in a macro cell region, which is connected to a macro cell (eNB) 110 and wired controlled by an optical cable or an optical fiber to the macro cell 110. It may be the RRH 112.

The terminal 120 recognizes one component carrier among three connectable component carriers as a primary cell (PC) and communicates with the first transmission / reception point 110, the second transmission / reception point 112, or both. PDCCH reception or control channel reception such as PDCCH is performed.

The network of FIG. 1 not only transmits the PDSCH to the current terminal 120 through one or both transmit / receive points, but also has the potential to transmit a physical downlink shared channel (PDSCH) to the terminal 120. After searching for the transmission / reception point, the terminal also allocates at least one optimal transmission / reception point to the terminal. The allocation information is transmitted to the terminal through one or both of two transmission and reception points constituting one network. Here, the allocation of the transmission and reception points means that the terminal 120 notifies the terminal 120 of information necessary for receiving a signal or channel from each transmission and reception point.

Hereinafter, downlink (downlink) means a communication or communication path from the transmission and reception point 110 to the terminal 120, uplink (uplink) indicates a communication or communication path from the terminal 120 to the transmission and reception point 110. it means. In downlink, the transmitter may be part of the transmission / reception point 110 and the receiver may be part of the terminal 120. In uplink, the transmitter may be part of the terminal 120 and the receiver may be part of the transmission / reception point 110.

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

As described above, in order to support smooth CoMP operation, multiple transmission / reception points 110 and 112 may have the same physical cell ID (PCID) for the same band. When the multiple transmit / receive points 110 and 112 have the same PCID for the same band, downlink transmit / receive point switching or uplink transmit / receive point switching is performed without a handover process, thereby more effectively network load balancing. ), And CoMP support is possible without additional signaling to the terminal.

As shown in (a) of FIG. 1, the CoMP system 100 in which multiple transmit / receive points 110 and 112 have the same PCI for the same band may be cell-specific using two or more transmit / receive points using the same resource. Cell-specific) Since some of the transmission / reception points constituting the CRS transmission or the network do not perform CRS transmission, the UE may not recognize some transmission / reception points, and thus, effective transmission / reception point operation may be difficult.

In particular, when a CA scheme and a CoMP scheme for allocating two or more component carriers to each terminal are used at the same time, a reduction in the selection efficiency of a transmission / reception point may cause more serious network efficiency degradation.

As shown in FIG. 1, two transmit / receive points 110 and 112 share the same cell ID for the same band, and each transmit / receive point 110 and 112 has three first to third component carriers. , CC0 to CC2) may be supported.

As shown in (a) of FIG. 1, the terminal 120 may be allocated a first CC (CC0) as a primary cell (Pcell) and an additional CC as a secondary cell (SCell). In this case, the link state between the first transmission / reception point 110 and the terminal 120 is in a bad and normal state with respect to the first component carrier CC0 and the second component carrier CC1, and the second transmission / reception point Assume that the link state between the 112 and the terminal 120 is a good and bad state for the second CC CC3 and the CC CC2.

The above-described first transmission / reception point 110 notifies each terminal 120 of a radio resource management (RRM) measurement object (RMR) measurement object in which the terminal should measure a link state through higher layer signaling, for example, RRC signaling. . The RRM measurement object includes a carrier frequency, a bandwidth, and a cell ID. Meanwhile, the network is also reporting configuration information on how the terminal 120 will report the RRM for the cells through the transmission / reception point (s) configured to be used for RRC signal transmission to each terminal 120. .

Each terminal 120 performs RRM measurement through cell-specific CRS based on RRM measurement object and reporting configuration information, and, if reporting is required, reports the measured RRM measurement result according to a report instruction. Report to one transmission and reception point (110).

In the aforementioned channel state, the terminal 120 performs the RRM measurement based on the cell-specific CRS transmitted by the first transmission / reception point 110 during the RRM measurement, thereby performing the second component carrier CC1. It is possible to report a link state of a normal state for the bad, third component carrier CC2. Accordingly, the network including the first transmission / reception point may select the second component carrier CC1 as the SCell of the terminal 120. As described above, the network recognizes the movement of the terminal based on the measurement result report information and performs a handover or cell (re) configuration. In the above example, the network may not use the link between the second transmission and reception point 112 and the terminal 120 which is a good channel. Because the second transmitting and receiving point 112 does not perform cell-specific CRS transmission or CRS transmission using the same resources as the first transmission and reception point, the terminal does not recognize the second transmission and reception point. This is because the second transmission / reception point 112 and the terminal 120 cannot measure the link state.

As shown in FIG. 1 (b), the present invention enables the terminal 120 to perform RRM measurement through CRS and CSI-RS in order to support more efficient CA and CoMP operation in the aforementioned CoMP system 100. It provides a method and apparatus. In addition, the present invention in the above-described CoMP system 100, the terminal 120 through the CRS and CSI-RS through the measurement results based on the RRM measurement, more effective transmission and reception point setting and cell (re) configuration (Cell (re) configuration) Is possible. As a result, the terminal 120 may recognize all transmission / reception points related thereto or measure a link state with all transmission / reception points.

In more detail, when the terminal 120 performs RRM measurement on the first to third component carriers CC0 to CC2 of each of two transmission and reception points, two measurement objects, CRS port 0 and CSI-RS port 15 or Each cell performs RRM measurement through at least one CSI-RS port including port 16, and compares the measurement results of these measurement objects to deliver the RRM measurement results for the optimal link of each cell to the network. By comparing the measurement results, it is possible to recognize the best cell and report the best cell to the network.

According to the present invention, the UE performs RRM measurement through CRS port 0 and RRM measurement through at least one CSI-RS port including CSI-RS port 15 or port 16 and reports the RRM measurement results to the network. And CA can be supported at the same time.

2 is a flowchart illustrating an RRM measuring method of a first transmission / reception point and a terminal according to another embodiment.

Referring to FIG. 2, in the network supporting CoMP, each terminal determines a target of RRM measurement (S210). The RRM measurement target may refer to a transmission / reception point and an element carrier allocated to the transmission / reception point and an object for measuring a measurement value of a reference signal received by the terminal as described below regardless of these.

Next, the network sends a higher layer message to the RRM measurement configuration element including an RRM measurement object including an RRM measurement object including information about a reference signal resource to be used for RRM measurement. For example, it transmits to the terminal 120 through RRC (Radio Resource Control) signaling and a downlink control channel (S220). At this time, the first transmission and reception point 110, the second transmission and reception point 112, or both may be used for information transmission.

The network uses the first transmission / reception point 110 or the second transmission / reception point 112 to allow the terminal 120 to perform RRM measurement through the CRS transmitted by the first transmission / reception point 110 through RRC signaling. The list information and the reference signal list information are transmitted to the terminal 120 so that the RRM measurement can be performed through the CSI-RS transmitted by the second transmitting / receiving point 112.

For example, the first transmission / reception point 110 may transmit the RRM measurement component to the terminal 120 through an RRC connection reconfiguration message. In this case, the reference signal may be a CRS and a CSI-RS, but is not limited thereto. Hereinafter, the CSI-RS will be mainly described as an example, but other types of reference signals are also the same.

Information on the CSI-RS resources to be used for the RRM measurement, the number of CSI-RS transmission ports, the location of the RE, information about the CSI-RS sequence, the transmission power offset with the PDSCH (sub) to which the CSI-RS is transmitted It includes all the information needed to measure channel status information, such as frame location information, or 1) the location of CSI-RS port 15 RE, 2) information on the CSI-RS sequence, and 3) the CSI-RS transmission. It may be information about a subframe or subframe offset. Information on at least one CSI-RS resource may be used to construct a CSI-RS list necessary for RRM measurement.

This RRM measurement configuration element may follow the form of a general measurement configuration that supports the control of UE mobility as follows.

1. Measurement object

The measurement object performs RRM measurement through cell list information and CSI-RS transmitted by the second transmission / reception point 112 so that the terminal 120 performs RRM measurement through the CRS transmitted by the first transmission / reception point 110. Reference signal list information is included to be performed.

A part of the measurement object or the first measurement object includes cell information including a frequency, a bandwidth, and a cell ID for performing CRS measurement as cell list information. The cell list information consists of at least one cell information.

Another part or second measurement object of the measurement object is a CSI-RS list and includes information on at least one CSI-RS resource or CSI-RS configuration information for each UE to perform RRM measurement. The reference signal list information includes at least one CSI-RS configuration information. Information on the CSI-RS resources is as follows.

a) information on a frequency and band (carrier frequency and bandwidth) for performing CSI-RS measurement and information on a cell ID for each CC. In this case, each CC has a different cell ID (PCI). In the above information, the information on the CC is defined by three values: a frequency and a band, a cell ID for each CC, and three values. Each component carrier and CSI-RS port 15 or port 16 to be measured in each component carrier and may include pairing information between at least one CSI-RS port. Alternatively, the following information about the CSI-RS may be defined for each CC.

b) CSI-RS port 15 includes information on the location of the mapped RE or at least one CSI-RS port is mapped to the location of the RE and the number of the port.

In the wireless communication system, as illustrated in FIG. 3, one, two, four, or eight CSI-RSs using patterns p = 15, p = 15,16, p = 15-18, and p = 15-22, respectively. Transmitted at the antenna port. Since all transmission / reception points performing CSI-RS transmission use CSI-RS port 15 regardless of the number of antennas, they are suitable for the RRM measurement of CSI-RS. In addition, it is also appropriate to use CSI-RS ports 15 and 16 as CSI-RS RRM measurement targets because CSI-RS configuration uses two or more ports for CSI-RS transmission in most cases. In the above case, among the tables representing the CSI-RS patterns of the 3GPP Rel-10, information on the location of the RE may be displayed by 5 bits using a table indicating the case where two CSI-RS ports are used.

The CSI-RS RRM measurement method is provided for the CSI-RS port 15 or the CSI-RS ports 15 and 16, but in addition, the RRM measurement is possible for at least one CSI-RS port. In both cases, the information on the location of the RE may be indicated by one or more indexes. The index may be selected using a table that illustrates the CSI-RS pattern defined in 3GPP Rel-10 or by using a portion of the table. Table showing the CSI-RS pattern of 3GPP Rel-10 shows the CSI-RS pattern represented by a specific number of bits, for example, 5 bits depending on whether the normal / extended CP is used, the FDD / TDD method, and the number of CSI-RS ports. The index may be selected to indicate the location of the REs used for CSI-RS transmission.

In the case of instructing power measurement for three or more ports in measuring the received power of each CSI-RS, the information about the RE position for each CSI-RS indicates an index indicating the number of ports and the CSI-RS pattern. It can be composed of an index.

For example, if only CSI-RS port 15 or CSI-RS ports 15 and 16 are used in measuring the received power of each CSI-RS, the information is used several times in the pattern defined in CSI-RS port 2. It can be composed of a factor of 5 bits indicating whether or not.

c) In measuring the CSI-RS, transmit information on the CSI-RS sequence to be considered when reviewing the RE.

The above information may be a direct factor indicating a CSI-RS sequence, a value for one of various factors used when generating a CSI-RS sequence, a value for the at least one factor, or It may be a value indicated by a combination of factors. For example, the initial value used to generate the CSI sequence,

는 셀 아이디)에 대한 정보를 전달함에 있어, 상기 값을 직접 전달하거나, 또는 셀 아이디인

에 대응되는 값을 전달하는 방식을 사용할 수 있다. Where n _s is the slot number of the frame and N _CP is the type of CP, which is 1 for normal CP and 0 for extended CP.

In transmitting information about a cell ID), the value is directly transmitted or is a cell ID.

You can use this method to pass a value corresponding to.

d) may include information on subframes to watch in measuring the CSI-RS.

The above information may be a location of a subframe in which each CSI-RS is transmitted, and may be a location of a subframe in which a UE should perform CSI-RS measurement among subframes in which each CSI-RS is transmitted.

The above information may be information indicating an exact position of a subframe in which each CSI-RS measurement should be performed, information on a period and subframe offset of a measurement in which the measurement should be performed, and perform CSI-RS measurement. It may be subframe offset information for a subframe to be performed.

For example, when offset = 20 is set, the UE performs the first measurement in the 20th subframe when measuring the CSI-RS and has the same 200ms period as the RRM (Radio Resource Management) measurement through the CRS. Measurement can be performed.

In summary, the information on the measurement object in the RRM measurement configuration element may consist of a combination of the following elements.

In order to transmit the above combination with the cell list indicating RRM measurement performed through CRS, the RRM measurement object configuration described with reference to FIGS. 4 and 5 may be configured.

4 and 5 are examples of an RRM measurement object configuration.

Referring to FIG. 4, when listing a cell list for performing RRM measurement in an RRM measurement object configuration, information may be included in a cell list in a frequency and band, a cell ID, and at least one CSI-RS resource.

Referring to FIG. 5, the RRM measurement object configuration may include a cell list for performing RRM measurement through CRS and a CSI-RS list for performing RRM measurement through CSI-RS as separate RRM measurement objects.

As shown in FIG. 5, the RRM measurement object MeasObjectCoM1 for performing RRM measurement through CRS includes a cell list of a frequency (Carrier freq), a bandwidth (Bandwidth), and a cell ID (CellID). In this case, the cell ID may be a PCI shared by the first transmission / reception point 110 and the second transmission / reception point 112 or an indicator indicating the same.

The RRM measurement object (MeasObjectCoM2) for performing RRM measurement through CSI-RS includes frequency (carrier freq) and bandwidth (bandwidth), cell ID (CellID), CSI-RS RE location (RELoc), and CSI-RS sequence (Sequence ID). ), A reference signal (CSI-RS) list of the position or offset of the subframe. In this case, the cell ID (CellID) is a PCI of the CC to which the CSI-RS is allocated or an indicator indicating the same.

In this case, since the object is added or removed through separate signaling, the information is modified or updated, and thus the UE may indicate a change in the CSI-RS configuration information to perform RRM measurement. For example, the information included in the measurement object may be modified in a format such as RSToAddList / RSToRemoveList (modify (add or remove).

2. Reporting configuration

Reporting configuration is composed of information indicating the measurement report of the terminal, each information consists of the following two elements as shown in Table 2.

Reporting configuration information, which may include information on the frequency of the received power (RSRP) reporting of the CSI-RS, and information for separately setting the period or offset of the measurement report for each band or CSI-RS It may be included in an RRM measurement configuration element, but is not limited thereto.

Reporting configuration is given as a list of information in Table 2.

3. Measurement identities

Measurement identities are information about linking between each measurement object and each reporting configuration. For example, two or more measurement objects can be linked to one reporting configuration, or two or more reporting configurations can be linked to the same measurement objects. .

Measurement identities are given in the list of information.

4. Measurement gaps

Measurement gaps define a time period during which the UE can perform measurement because uplink or downlink transmission is not scheduled. For each CSI-RS signal for which the UE should perform CSI-RS measurement, a different measurement period may be set or the same measurement period may be set. When there is no separate instruction, the UE performs power measurement at the same period for all CSI-RS signals. When there is no separate instruction, the UE performs CSI-RS measurement at a specific period, for example, a period of 200 ms.

Next, the first transmission / reception point 110 transmits the CRS to the first to third component carriers CC0 to CC3 (S230). In this case, in step S230, the transmission and reception point 112 transmits the CSI-RS to the first to third component carriers CC0 to CC3. The terminal 120 receives the CRS and the CSI-RS from two or more transmission and reception points.

The terminal 120 performs RRM measurement through the CRS transmitted by the first transmission / reception point 110 based on the cell list information included in the received RRM measurement object, and the second transmission / reception point 112 based on the CSI-RS list. RRM measurement is performed through CSI-RS which is transmitted by S).

The terminal 120 reports the RRM measurement information to a transmission / reception point selected for reporting as a measurement result based on the received reporting configuration information. (S250). The transmission / reception point selected for reporting may be the first transmission / reception point 110.

In other words, the terminal 120 receives from the second transmission / reception point 112 based on at least one RRM measurement and reference signal list information measured through the CSR received from the first transmission / reception point 110 based on the cell list information. The RRM measurement result obtained from at least one RRM measurement measured through the CSI-RS is transmitted to a transmission / reception point selected for reporting. The transmission / reception point selected for reporting may be the first transmission / reception point 110. The terminal 120 may report the RRM measurement information by higher layer signaling, for example, RRC signaling. For example, the first transmission / reception point 110 may receive the RRM measurement result from the terminal 120.

The RRM measurement information may be a reference signal received power (RSRP), which is a reference signal reception power, but is not limited thereto, and may be one of a received signal strength indicator (RSSI) and a reference signal received quality (RSRQ). Also, it may be another value derived from the CSI-RS received power, and may be information about the relative strength or the magnitude of the signal strength and interference calculated by each CSI-RS received power and other CSI-RS received power. Or information about a ratio of interference measured through CSI-RS received power and other signals or channels. Alternatively, the information may include two values of CSI-RS received power and interference.

The terminal 120 reports the RRM measurement value to the network periodically as a result of the RRM measurement, or (2) reports the network request aperiodically, or the network including the first transmission / reception point 110 controls the CoMP measurement set. For CSI-RS receive power report via PDCCH. (3) When it is detected that there is a change in channel state (when a specific event occurs), it can report to the network. In order to support the above-mentioned method (1), an uplink radio resource to be used for the above information reporting may be previously selected and notified to the terminal. The above notification may be included in the information indicating the RRM measurement defined by the present invention.

The terminal 120 obtains two or more RRM measurements for each cell or CC (CC0 to CC2) through CRS and CSI-RS, and various methods as described with reference to FIGS. 6 to 8. By comparing the RRM measurement values, the RRM measurement value for each cell may be determined, and the RRM measurement value may be reported to the network through one or more transmission / reception points.

FIG. 6 is a flowchart illustrating an embodiment of determining an RRM measurement value of a terminal in S240 of FIG. 2.

Referring to FIG. 6, the terminal 120 performs RRM measurement on each cell or component carrier CC0 through CC2 through CRS based on cell list information included in the received RRM measurement object. RRM _CRS for CC0, RRM _CRS for CC1, and RRM _CRS for CC2) are acquired (S610).

The terminal 120 measures RRM measurement values (RRM _{CSI - RS} for CC0, RRM) for each cell or CC (CC0 to CC2) through the CSI-RS based on the CSI-RS list. _{CSI - RS} for CC1, RRM _{CSI - RS} for CC2) is obtained (S620).

The terminal 120 sequentially transmits two RRM measurement values (RRM _CRS for CCn, RRM _{CSI - RS)} for each CC through CRS and CSI-RS from the first CC CC3 to the third CC CC2. for CCn) (n = 0 to 2) is compared (S630).

If the RRM measurement value (RRM _CRS for CCn) for the n-th component carrier through the _CRS is greater than or equal to the RRM measurement value (RRM _CSI-RS for CCn) for the n-th component carrier through the _CSI-RS , 120 determines the RRM measurement value (RRM _CRS for CCn) for the n-th component carrier as the RRM measurement value (RRM for CCn) for the n-th component carrier through the _CRS (S640).

If the RRM measurement value (RRM _CRS for CCn) for the n-th component carrier through the _CRS is smaller than the RRM measurement value (RRM _{CSI - RS} for CCn) for the n-th component carrier through the _{CSI - RS} , the terminal 120 The RRM measurement value (RRM _{CSI - RS} for CCn) for the n-th component carrier is determined as the RRM measurement value (RRM for CCn) for the n-th component carrier through the _{CSI - RS} (S650).

As a result, as shown in FIG. 1B, the terminal 120 is good for the first CC CC0, good for the second CC CC1, and third CC. Report the RRM measurement for the link that is bad for (CC2). When reporting the results, a factor indicating whether the RRM for each cell is measured based on CRS or measured through CSI-RS may be reported together.

 The network allocates the second component carrier CC1 to the terminal as the SCell based on the RRM measurement result. After the assignment, the network recognizes that the second component carrier CC1 shows high link performance for the link between the second transmission / reception point 112 and the terminal 120 by a separate terminal report. CC1) transmits information through the second transmission / reception point 112 (RRH) during downlink communication. Alternatively, when the RRM is reported together with a factor indicating whether the RRM is measured based on the CRS or the value measured through the CSI-RS, the downlink is determined using a second CC using a second transmission / reception point. It can also be set to perform communication.

Although not shown, the network determines a measurement set as a target to measure channel state information using the information reported by the terminal and transmits the measurement set information to the terminal 120. The terminal 120 receives the CSI-RS from the transmission and reception points and measures channel state information by using the CSI-RS of the transmission and reception points corresponding to the measurement set. The terminal 120 reports channel state information of the transmission / reception points corresponding to the measurement set to the transmission / reception point (s) selected for CSI reporting through PUCCH / PUSCH. In this case, the selected transmission / reception point may be the first transmission / reception point 110. In addition, when it is determined that the measurement set needs to be changed in consideration of the CSI-RS RRM measurement result report of the UE, the network (base station, transmitting end) transmits a transmission / reception point selected for the information leaflet (or PDSCH transmission). It can be used to notify the terminal by <measurement set information>. The selected transmission / reception point may be the first transmission / reception point 110.

Next, at least one transmission / reception point and the terminal 120 cooperatively communicate (transmit), thereby driving CoMP / CA (operation). CoMP driving (operation) may be joint processing (JP, hereinafter referred to as "JP") and cooperative scheduling / beamforming (Coordinated Scheduling / Beamforming, called "CS / CB"). In this case, a carrier aggregation (CA) that communicates using CoMP and two or more CCs may be simultaneously implemented for each UE, and only one of the two may be supported at each instant.

Meanwhile, the first component carrier CC0 and the second component carrier CC1 operate as CoMPs of the first transmission / reception point 110 and the second transmission / reception point 112, and the third component carrier CC2 is the first transmission / reception point ( 110).

In addition, only the first CC (CC0) and the first and second transmission points 110, 112 operate in CoMP and the second CC (CC1) is assigned only to the second transmission and reception point 112, RRH and the third element The carrier CC2 may be allocated only to the first transmission / reception point 110 (eNB).

In addition, the first component carrier CC0 supports CoMP driving of the first transmission / reception point 110 and the second transmission / reception point 112, and the second component carrier CC1 supports the second transmission / reception point 112 (RRH). To receive, the third component carrier CC2 may support receiving through the first transmission / reception point 110 (eNB).

As another embodiment, the terminal 120 may separate the RRM measurement through the CRS and the RRM measurement through the CSI-RS and report the information to the network as separate information. As described with reference to FIG. 6, instead of the terminal 120 reporting one RRM value to the network for the first to third component carriers CC0 to CC2, CRS based RRM for each component carrier (CC). And CSI-RS-based RRM measurement values are separately reported to report two RRMs for each cell to the network, and the network compares the above values to determine whether to support CoMP for each CC and to select an optimal transmit / receive point for each CC, and add a SCell. The work can be done at the same time.

7 shows another example of a wireless communication system to which embodiments are applied.

Referring to FIG. 7, in the wireless communication system, one first transmission / reception point 110 and second and third transmission / reception points 112 and 114 may share the same cell ID. The terminal 120 performs RRM measurement through one CRS and two CSI-RSs for each cell.

Looking at the configuration of the CSI-RS resources on the CoMP network, (1) the transmission and reception point having the same PCID (Physical Cell ID, Cell Unique Index, PCI) can use at least one CSI-RS resource, and (2) different PCID At least one transmission / reception point used may have the same CSI-RS resource, and (3) at least one transmission / reception point (having the same PCID or different PCID) may constitute one CSI-RS resource. In other words. The CSI-RSs transmitted by the at least one transmitting end may be combined to form one CSI-RS. Two or more transmitters may transmit different CSI-RSs, but the UE may recognize one or more of the two transmissions as one CSI-RS transmission. In other words, each transmit / receive point may transmit a subset (or subset) of CSI-RS.

FIG. 8 is a flowchart of another embodiment of determining an RRM measurement value of a UE in S240 of FIG. 2.

Referring to FIG. 8, the terminal 120 performs RRM measurement on each cell or each CC (CC0 to CC2) through the CRS based on the cell list information included in the received RRM measurement object to measure the RRM measurements. (RRM _CRS for CC0, RRM _CRS for CC1, RRM _CRS for CC2) is acquired (S810).

The terminal 120 performs RRM measurement values (RRM _{CSI - RS} for CC0,) for each cell or each component carrier CC0 to CC2 of the second and third transmission / reception points through the CSI-RS based on the CSI-RS list. RRM _{CSI - RS} for CC1, RRM _{CSI - RS} for CC2) is acquired (S820).

The terminal 120 determines, as the RRM measurement results, three RRM measurements for one CRS and two CSI-RSs for the same frequency band or component carrier, or an RRM measurement based on two CSI-RSs. The RRM measurement value for the highest value (the best link state) and the RRM measurement value for the CRS can be determined as the RRM measurement result. Alternatively, the highest value of all the RRM measurement values may be determined as the RRM measurement result (S830). In this case, a high RRM measurement means an RRM measurement for a good link.

The terminal 120 may report the measurement result to the network. In this case, a factor indicating whether the RRM is measured through CRS or CSI-RS may be transmitted, or a factor indicating which CSI-RS is measured through the RRM may be transmitted.

In the above description, the RRM measuring method according to the embodiment of the present invention has been described as being performed by the same procedure as in FIGS. Depending on the implementation method, the execution procedure of each step may be changed, two or more steps may be integrated, or one step may be performed in two or more steps.

9 is a block diagram illustrating a terminal and a transmission / reception point according to another embodiment.

Referring to FIG. 9, the transmission / reception point 910 performs the operation of the first transmission / reception point 110 described with reference to FIG. 2. In more detail, the transmission / reception point 910 includes a transmission / reception unit 912 and a CoMP / CA operation unit 914.

The transceiver 912 includes cell list information including at least one cell information including a carrier frequency, a bandwidth, and a cell ID, and information on at least one CSI-RS resource. Reference signal list information is transmitted to the terminal 920. Also, the transceiver 912 may include at least one RRM measurement measured through a CSR based on cell list information and at least one RRM measurement measured through a CSI-RS received from another transmit / receive point based on reference signal list information. The RRM measurement result for the specific frequency band obtained is received from the terminal 920.

The CoMP / CA operation unit 914 selects a specific frequency band as the SCell by reflecting the RRM measurement result. The CoMP / CA operation unit 914 simultaneously performs CoMP and CA operations based on the measurement result.

The terminal 920 performs an operation of the terminal 120 described with reference to FIG. 2. In more detail, the terminal 920 includes a transceiver 922 and a measurement unit 924.

The transceiver 922 includes cell list information including at least one cell information including a carrier frequency, a bandwidth, and a cell ID, and information on at least one CSI-RS resource. Reference signal list information is received from one transmission / reception point among the transmission / reception points. The transceiver 922 transmits the RRM measurement result to one transmission / reception point.

The transceiver 722 receives measurement set information from the transmission and reception point 710 and transmits channel state information about the measurement set to the transmission and reception point 710.

The measurement unit 924 may receive the CSI-RS received from at least one other transmit / receive point based on at least one RRM measurement and reference signal list information measured through the CRS received from one transmit / receive point based on cell list information. The RRM measurement result for a specific frequency band is obtained from at least one RRM measurement measured through the measurement.

The measuring unit 924 measures the channel state of the measurement set and obtains the channel state information.

Although the embodiments have been described with reference to the drawings, the present invention is not limited thereto.

Although the CSI-RS has been described as a downlink reference signal in the above-described embodiment, it may be another downlink reference signal, for example, a DM-RS, or may be a reference signal defined or standardized in the future.

In the above-described embodiment, the number of element carriers has been described as three, but the present invention is not limited thereto. In other words, the number of component carriers may be one or more.

In the above-described embodiment, the number of transmission and reception points corresponding to the RRH has been described as an example or two, but the present invention is not limited thereto. The number of transmission / reception points corresponding to the RRH may be one or more.

In the above-described embodiment, RRC signaling consisting of a combination of CSI-RS resource information and CSI-RS measurement indication information for RRM measurement is defined as RRM set or RRM set information. However, the present invention is limited to the aforementioned name or definition. The RRM may be named in various ways such as an RRM measurement control set. In addition, the present invention has been described in the case where the RRC signaling is defined in a separate configuration or set, but the present invention is not limited thereto, and the above signaling may be included as part of another RRC signaling configuration.

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 protection scope of the present invention should be interpreted by the following claims, and all technical ideas within the equivalent scope should be interpreted as being included in the scope of the present invention.

Claims (9)

In a wireless communication system in which two or more transmission and reception points and the terminal cooperative communication,
The cell list information including at least one cell information including a carrier frequency, a bandwidth, and a cell ID, and reference signal list information including information on at least one CSI-RS resource, may be used. Transmitting to the terminal; And
At least one RRM measurement measured through the CSR received based on the cell list information and at least one RRM measured through CSI-RS received from another transmission / reception point based on the reference signal list information RRM measurement method of a transmission and reception point comprising the step of receiving from the terminal an RRM measurement result for a specific frequency band obtained from the measurement. The method of claim 1,
The CSI-RS resource information includes at least one of a frequency and a bandwidth, RE location information of the CSI-RS, CSI-RS sequence information, and CSI-RS subframe information. RRM measurement method of transmitting and receiving point. The method of claim 1,
The RRM measurement result is selected from at least one of the RRM measurement measured by the CSR and the at least one RRM measurement measured by the CSI-RS for the same frequency band and transmitted to the terminal as the RRM measurement result for the same frequency band RRM measurement method of a transmission and reception point, characterized in that. The method of claim 1,
RRM measurement method of the transmission and reception point further comprising the step of selecting a specific frequency band to the SCell reflecting the RRM measurement results. In a wireless communication system in which two or more transmission and reception points and the terminal cooperative communication,
Transmitting and receiving cell list information including at least one cell information including a carrier frequency, a bandwidth, and a cell ID, and reference signal list information including information on at least one CSI-RS resource Receiving from a transmit / receive point of one of the points;
CSI- received from at least one RRM (Radio Resource Management) measurement measured through the CRS received from the one transmit / receive point based on the cell list information and at least one other transmit / receive point based on the reference signal list information Obtaining an RRM measurement result for a specific frequency band from at least one RRM measurement measured through RS; And
And transmitting the RRM measurement result to the one transmission / reception point. The method of claim 5,
The CSI-RS resource information includes at least one of a frequency and a bandwidth, RE location information of the CSI-RS, CSI-RS sequence information, and CSI-RS subframe information. RRM measurement method of the terminal. The method of claim 5,
The RRM measurement result is an RRM measurement result for the same frequency band by selecting at least one of an RRM measurement measured through a CSR and at least one RRM measurement measured through a CSI-RS for the same frequency band. RRM measurement method of the terminal. In a wireless communication system in which two or more transmission and reception points and the terminal cooperative communication,
The cell list information including at least one cell information including a carrier frequency, a bandwidth, and a cell ID, and reference signal list information including information on at least one CSI-RS resource, may be used. Measured through the CSI-RS received from another transmission point based on at least one RRM (Radio Resource Management) measurement and reference signal list information transmitted to the terminal, measured via the received CSR based on the cell list information A transceiver for receiving an RRM measurement result for a specific frequency band obtained from at least one RRM measurement from the terminal; And an operation unit performing a CoMP operation based on the measurement result. In a wireless communication system in which two or more transmission and reception points and the terminal cooperative communication,
Transmitting and receiving cell list information including at least one cell information including a carrier frequency, a bandwidth, and a cell ID, and reference signal list information including information on at least one CSI-RS resource A transceiver for receiving from one transmit / receive point of the points and transmitting the following Radio Resource Management (RRM) measurement result to the one transmit / receive point; And
At least one RRM measurement measured through the CRS received from the one transmit / receive point based on the cell list information and measured through the CSI-RS received from at least one other transmit / receive point based on the reference signal list information A terminal comprising a measurement unit for obtaining the RRM measurement results for a specific frequency band from the at least one RRM measurement.

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