KR20100100578A - The method for performing comp operation and transmitting feedback information in wireless communication system - Google Patents

Abstract

PURPOSE: A CoMP(Coordinated Multi-Point) operation performing and feedback information transfer method in a wireless communications system is provided to perform CoMP operation and transmit feedback information. CONSTITUTION: A measurement module(411) measures an interference distribution value by using reference signal received from an adjacent cell. The noises and interference distribution value include the signal intensity or the interference level. A transmission module(430) transmits the noises, the interference distributed intelligence and PMI(Precoding Matrix Index) information to a base station. The noises and interference distributed information includes the measured noises and the interference distribution value. The PMI information is information for the specific adjacent cell.

Description

The method for performing CoMP operation and transmitting feedback information in wireless communication system}

The present invention relates to a wireless communication system, and more particularly, to a method of performing a CoMP operation in a wireless communication system.

Coordinated Multi-Point (CoMP) systems (hereinafter referred to as CoMP systems) are designed to improve throughput for users at cell boundaries by applying improved multiple-input multiple-output (MIMO) transmissions in multicell environments. System. Application of the CoMP system can reduce inter-cell interference in a multi-cell environment. Using this CoMP system, the terminal can be jointly supported data from the multi-cell base station (Multi-cell base-station).

In addition, each base station can improve the performance of the system by simultaneously supporting one or more terminals (UE 1, UE 2, ... UE K) by using the same radio frequency resource (Same Radio Frequency Resource). Also, the base station may perform a space division multiple access (SDMA) method based on channel state information (CSI) between the base station and the terminal.

The CoMP scheme can be divided into Co-MIMO (JP) Joint Processing (Co-MIMO) and Cooperative Scheduling / Beamforming Scheme (CS / CB) through data sharing. .

FIG. 1 conceptually illustrates CoMP of an existing intra eNB and an inter eNB.

Referring to FIG. 1, intra base stations 110 and 120 and inter base stations 130 exist in a multi-cell environment. In Long Term Evolution (LTE), an intra base station consists of several cells (or sectors). Cells belonging to a base station to which a specific terminal belongs have a relationship with a specific terminal and an intra base station (110, 120). That is, the cells sharing the same base station as the cell to which the terminal belongs are cells corresponding to the intra base stations 110 and 120, and cells belonging to other base stations become cells corresponding to the inter base station 130. As such, cells based on the same base station as a specific terminal exchange information (for example, data and channel state information (CSI)) through an x2 interface or the like, but cells based on other base stations Information may be exchanged between cells through the backhaul 140 and the like.

As shown in FIG. 1, a single cell MIMO user 150 within a single cell communicates with one serving base station in one cell (sector), and the multi cell MIMO user 160 located at the cell boundary is a multi cell (sector). Can communicate with multiple serving base stations.

Hereinafter, a spatial channel matrix that can be used as feedback information will be briefly described.

Where H (i, k) is the spatial channel matrix, h _{r , t} (i, k) is an element of the channel matrix H (i, k), Nr is the number of receive antennas, Nt is the number of transmit antennas, r is the receive antenna Is the index of the transmission antenna, i is the index of the OFDM (or SC-FDMA) symbol, k is the index of the subcarrier.

는 채널 행렬 H(i,k)의 요소(element)로서, i번째 심볼 및 k번째 부반송파상에서의 r번째 채널 상태 및 t번째 안테나를 의미한다.

Denotes an element of the channel matrix H (i, k) and denotes the r th channel state and the t th antenna on the i th symbol and the k th subcarrier.

In addition, the spatial channel covariance matrix that can be used in the present invention will be briefly described. The spatial channel covariance matrix can be represented by the symbol R.

이고, 여기서 H는 공간 채널 행렬을, R은 공간 채널 공분산 행렬을 의미한다. E[]는 평균(mean)을 의미하며, i는 심볼 인덱스, k는 주파수 인덱스를 의미한다.

Where H is a spatial channel matrix and R is a spatial channel covariance matrix. E [] means mean, i means symbol index, and k means frequency index.

Singular Value Decomposition (SVD) is one of the important methods of decomposing rectangular matrices and is widely used in signal processing and statistics. Singular value decomposition is a generalization of the spectral theory of matrices for arbitrary rectangular matrices. Using spectral theory, orthogonal square matrices can be decomposed into diagonal matrices based on eigenvalues. Assume matrix H is an m × m matrix of real or complex set elements. The matrix H can be expressed as the product of three matrices as follows.

이다. 이와 같이 세 행렬의 곱으로 나타내는 것을 특이값 분해라고 한다. 특이값 분해는 직교 정사각행렬만을 분해할 수 있는 고유값 분해보다 훨씬 일반적인 행렬을 다룰 수 있다. 이러한 특이값 분해와 고유값 분해 서로 관련되어 있다.Where U and V represent unitary matrices, and ∑ is an m × n diagonal matrix containing nonnegative singular values. Singular values are

to be. This multiplication of three matrices is called singular value decomposition. Singular value decomposition can handle matrices much more general than eigenvalue decomposition, which can only resolve orthogonal square matrices. These singular value decompositions and eigenvalue decompositions are related to each other.

When matrix H is a Hermitian matrix with positive definite, all eigenvalues of H are nonnegative real numbers. At this time, the singular value and singular vector of H are all non-negative real numbers of H. The singular values and singular vectors of H are equal to the eigenvalues and eigenvectors of H.

Eigen Value Decomposition (EVD) can be expressed as follows.

The eigenvalues may be λ _{1, ..,} λ _r .

Up to now, as the terminal transmits only the PMI value as feedback information, it is difficult for the base station to rank the PMI values. Therefore, there is a problem that the efficiency and accuracy of performing the CoMP operation due to the PMI ranking problem.

An object of the present invention is to provide a method of performing a CoMP operation and a method of transmitting feedback information in a wireless communication system.

Another object of the present invention is to provide a terminal device performing a CoMP operation and transmitting feedback information in a wireless communication system.

Another object of the present invention is to provide a base station apparatus for performing CoMP operation in a wireless communication system.

The technical problems to be solved by the present invention are not limited to the technical problems and other technical problems which are not mentioned can be understood by those skilled in the art from the following description.

In order to achieve the above technical problem, the method for transmitting CoMP feedback information according to the present invention includes precoding matrix index (PMI) set information desired to be restricted or recommended for a specific neighbor cell performing the CoMP operation to a serving base station. Transmitting, and a difference between a strength or interference level of a signal calculated by applying the PMI set to the specific neighbor cell and a signal or interference level of the signal calculated when the PMI set information is not applied. And transmitting a signal strength gain value or an interference level gain value, which is a gain value, to the serving base station.

In order to achieve the above technical problem, the method for transmitting CoMP feedback information according to the present invention uses a reference signal received from one or more adjacent cells to measure noise and interference variance values corresponding to signal strength or interference level. And transmitting, to the serving base station, noise and interference variance information including the measured noise and interference variance values, and PMI (Precoding Matrix Index) information to be limited or recommended for a specific neighbor cell performing the CoMP operation. It has a step.

In order to achieve the above another technical problem, the terminal device according to the present invention, the measurement module for measuring the noise and interference dispersion value including the signal strength or interference level using a reference signal received from one or more adjacent cells And transmitting noise and interference variance information including the measured noise and interference variance values and precoding matrix index (PMI) information to a serving base station to limit or recommend to a specific neighbor cell performing the CoMP operation. With a module.

According to the present invention, the terminal and the base station can perform the CoMP operation more efficiently.

Effects obtained in the present invention are not limited to the above-mentioned effects, and other effects not mentioned above may be clearly understood by those skilled in the art from the following description. will be.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. The detailed description, which will be given below with reference to the accompanying drawings, is intended to explain exemplary embodiments of the present invention and is not intended to represent the only embodiments in which the present invention may be practiced. The following detailed description includes specific details in order to provide a thorough understanding of the present invention. However, one of ordinary skill in the art appreciates that the present invention may be practiced without these specific details. For example, the following detailed description will be described in detail on the assumption that the mobile communication system is a 3GPP LTE system, but is applicable to any other mobile communication system except for the specific matter of 3GPP LTE.

In some instances, well-known structures and devices may be omitted or shown in block diagram form centering on the core functions of the structures and devices in order to avoid obscuring the concepts of the present invention. In addition, the same components will be described with the same reference numerals throughout the present specification.

In addition, in the following description, it is assumed that a terminal (or user device) collectively refers to a mobile or fixed user terminal device such as a user equipment (UE) or a mobile station (MS). In addition, it is assumed that the base station collectively refers to any node of the network side that communicates with the terminal, such as Node B, eNode B, Base Station.

In a mobile communication system, a user equipment may receive information from a base station through downlink, and the terminal may also transmit information through uplink. The information transmitted or received by the terminal includes data and various control information, and various physical channels exist according to the type and purpose of the information transmitted or received by the terminal.

FIG. 2 is a diagram for explaining physical channels used in a 3rd Generation Partnership Project (3GPP) Long Term Evolution (LTE) system, which is an example of a mobile communication system, and a general signal transmission method using the same.

The terminal which is powered on again or enters a new cell while the power is turned off performs an initial cell search operation such as synchronizing with the base station in step S201. To this end, the UE receives a primary synchronization channel (P-SCH) and a secondary synchronization channel (S-SCH) from the base station, synchronizes with the base station, and obtains information such as a cell identifier (Identifier). can do. Thereafter, the terminal may receive a physical broadcast channel from the base station to obtain broadcast information in a cell. Meanwhile, the UE may check a downlink channel state by receiving a downlink reference signal (DL RS) in an initial cell search step.

After the initial cell search, the UE receives a physical downlink control channel (PDCCH) and a physical downlink control channel (PDSCH) according to the physical downlink control channel information in step S202. Specific system information can be obtained.

On the other hand, when the first access to the base station or there is no radio resource for signal transmission, the terminal may perform a random access procedure (Sandom Access Procedure), such as step S203 to step S206 to the base station. To this end, the UE may transmit a specific sequence as a preamble through a physical random access channel (PRACH) (S203) and receive a response message for the random access through the PDCCH and the corresponding PDSCH. There is (S204). In case of contention-based random access except for handover, a contention resolution procedure such as transmission of additional PRACH (S205) and PDCCH / PDSCH reception (S206) may be performed.

After performing the procedure as described above, the UE performs a PDCCH / PDSCH reception (S207) and a physical uplink shared channel (PUSCH) / physical uplink control channel (PUCCH) as a general uplink / downlink signal transmission procedure. Physical Uplink Control Channel) transmission (S208) may be performed. In this case, the control information transmitted by the terminal to the base station through the uplink or received by the terminal from the base station includes a downlink / uplink ACK / NACK signal and a channel quality indicator (CQI: hereinafter referred to as 'CQI') / free. A coding matrix index (PMI) (hereinafter referred to as 'PMI') / rank indicator (RI) may be included. In the 3GPP LTE 3rd Generation Partnership Project Long Term Evolution (LTE) system, the UE may transmit control information such as CQI, PMI, RI, and the like through a PUSCH and / or a PUCCH.

The term base station used in the present invention may be referred to as a cell or sector when used in a regional concept. The serving base station (or cell) may be regarded as a base station (or cell) that provides a main service to the terminal and may transmit and receive control information on a coordinated multiple transmission point. In this sense, the serving base station (or cell) may be referred to as an anchor base station (or cell). The serving base station may transmit various types of information received from the terminal to a neighbor base station (cell). Likewise, a neighbor base station may be referred to as a neighbor cell when used in a regional concept. One CoMP set refers to a set of cells that perform a CoMP operation.

Using the CoMP scheme in a multi-cell environment can improve the communication performance of the cell edge terminal. This CoMP method includes cooperative MIMO-type joint processing (JP: Joint Processing) through data sharing and cooperative scheduling / beamfobbing (CS / CB: Coordinated Scheduling / Beamforming) to reduce inter-cell interference such as worst companion and best companion. And the like. Here, the worst companion method is a method in which the UE reports the PMI with the most interference to the cells performing CoMP to the serving base station, so that the cells can remove the inter-cell interference using the PMI of the next lane except the corresponding PMI. to be. The best companion method is a method of reducing interference between cells by using the PMI corresponding to the cells by reporting the least interference PMI for the cells performing the CoMP.

In order to efficiently perform such a CoMP operation scheme, it is necessary for the UE to define measurement information measuring the interference level (or signal strength) of neighbor cells and feedback information for transmitting to a serving base station. have. That is, in the CoMP operation, an efficient CoMP operation can be performed by defining the overall operation procedure through the measurement procedure of the terminal and the CoMP Active Set. Here, the CoMP active set refers to a transmission point set for serving a specific terminal and actually performing CoMP transmission.

In case of operating in cooperative scheduling and beamforming (CS / CB) scheme among CoMP operation schemes, the UE restricts and / or recommends to an adjacent cell (hereinafter, abbreviated as 'CoMP neighbor cell') that performs CoMP operation. PMI information desired to be transmitted may be transmitted to the serving base station. When a plurality of UEs perform CoMP operation, when PMI information desired to be restricted and / or recommended for CoMP neighbor cells increases, the corresponding CoMP neighbor cell selects a PMI that can be restricted and / or recommended from the received PMI information. It is desirable to. Accordingly, the CoMP neighbor cell requested for the PMI restriction and / or recommendation request of the UE may determine the ranking of the PMI that is restricted and / or recommended. As such, the CoMP neighbor cell may determine the rank of the limited and / or recommended PMI using the received restriction and / or recommended PMI information. However, it is not desirable to determine PMI for PMI restriction and / or recommendation request using only PMI information received by CoMP neighbor cell.

Accordingly, the present invention proposes a method for helping CoMP neighbor cells to efficiently determine PMI rank. As one of the proposed methods, the terminal may consider a method of transmitting additional information as well as PMI information to a serving base station performing a CoMP operation. The UE may transmit such additional information when 1) configures a CoMP set, and 2) transmits PMI information during CoMP operation.

First, a method of transmitting additional information by the terminal when configuring a CoMP set will be described.

CoMP set may be configured based on the measurement information of the interference level (or signal strength) and the like measured by the UE for the neighbor cell. CoMP set configuration has the advantage of having flexibility in CoMP set configuration by configuring the CoMP set for the adjacent cell that directly affects the actual terminal based on the terminal measurement. The terminal may perform the measurement such as the interference level for the neighbor cell based on the neighbor cell list. Such a UE may receive a neighbor cell list from a serving base station or the like in advance to configure a CoMP set. Alternatively, the terminal may form a neighbor cell list by directly measuring the neighbor cell.

Measurement information about the interference level (or signal strength) that the UE measures for the neighbor cell for CoMP set configuration may be represented by various types of values. Examples of these various types of values include Reference Signal Received Power (RSRP), Reference Signal Received Quality (RSRQ), Reference Signal Strength Indicator (RSSI), and Propagation (PD). Delay), Carrier to Interference plus Noise Ratio (CINR) value or signal-to-interference for the neighboring cell measured when the neighboring cell used good PMI or bad PMI. Signal to Interference plus Noise Ratio (SINR) value, measured CINR value or SINR value when the adjacent cell does not use good PMI or bad PMI, or previously measured CINR value, or There is an improved CINR value or SINR value for the serving cell that indicates how much the channel state of the serving cell is improved by comparing the difference with the SINR value. In particular, the improved CINR value or SINR value may help determine the PMI rank in the adjacent cell. Before the UE applies the measured CINR value or SINR value and the limit and / or recommended PMI when the neighbor cell does not use the bad PMI recommended by the UE or limit the bad PMI recommended by the UE. A value corresponding to the difference between the measured CINR value or the SINR value may be generated and transmitted to the base station. Adjacent cells receiving this information from the serving base station may be able to determine the degree of improvement of the channel state based on the difference value of the CINR value or SINR value, and thus may be easy to determine the PMI rank.

As described above, in the LTE system, the UE can measure the channel quality state between the UE itself and the cell by using an improved CINR value or SINR value corresponding to the power of the pilot signal, RSRP, and the like. Here, the reference signal reception power refers to a linear average of power distributed to resource elements to which a cell-specific reference signal is allocated within the considered measurement frequency bandwidth. The power of each resource element on the resource block may be determined from the energy received from the valid interval of the symbol except for the cyclic prefix (CP). The reference signal reception power may be applied to the terminal in both the RRC_idle state and the RRC_connected state. In addition, when receiver diversity is used by the terminal, the reported value will be equal to the linear average of the power values of all diversity branches.

The UE may transmit the above-described various types of measurement values to the serving base station in addition to the PMI information desired to be limited and / or recommended for the CoMP neighbor cell. Meanwhile, the UE may transmit the various types of measurement values additionally transmitted when the CoMP set is configured to the serving base station even during the CoMP operation, and perform the measurement such as the interference level for the CoMP neighbor cell again during the CoMP operation. The measured values of may be transmitted to the serving base station.

Based on the measurement (eg, reference signal reception power measurement) of the neighbor cell of the terminal, the terminal may report information necessary for configuring the CoMP set to the serving base station. The information reported to the serving base station may include cell ID information of the neighbor cell together with one or more values of the above-described measured values of the neighbor cell. When the terminal directly forms the neighbor cell list, the terminal may directly upload cell ID information about the measured neighbor cell.

When the serving base station provides the terminal with a list of neighbor cells in advance, the terminal transmits an RSRP value measured for the corresponding cell in a predefined cell ID order, or adds an index corresponding to the cell ID in addition to the measured value. It can be transmitted to the serving base station. Alternatively, the terminal may arrange the index information corresponding to the cell ID in the order of the interference level and the like, and transmit the index and the interference level, which is a measurement value corresponding to the index, to the serving base station.

The serving base station may receive from the terminal PMI information and interference level information that the terminal desires to limit and / or recommend for CoMP neighbor cells. The serving base station may transmit the received PMI information and the interference level information to the CoMP neighbor cell. The CoMP neighbor cell that has received this information can determine the PMI to be restricted and / or recommended using the PMI information and interference level information that the UE wants to limit and / or recommend, and can provide PMI rank information for the determined PMIs. Can be generated. In this case, the CoMP neighbor cell may determine the PMI to be limited and / or recommended only by PMI counting without interference level information. That is, the PMI rank may be determined based on the number of limited and / or recommended PMIs for the CoMP specific neighbor cell. However, if the number of UEs performing CoMP is small or the number of PMIs requesting restriction and / or recommendation for CoMP neighbor cells is the same, there is a risk of ambiguity about which PMI to select. Nevertheless, the CoMP neighbor cell may reduce the overhead burden associated with additionally transmitting feedback information by the UE and the base station by determining the PMI that has received the most limited and / or recommendation request.

The case where PMI information and additional information are transmitted during CoMP operation will be described.

When configuring a CoMP set or performing a CoMP operation without configuring a CoMP set, the UE may transmit a selected PMI to a serving base station to limit and / or recommend for a neighboring cell that interferes. When the terminal transmits the PMI to perform the cooperative scheduling scheme while performing the CoMP operation, the serving base station may solve the problem of determining the PMI rank by using interference level information received from the terminal when configuring the CoMP set. That is, when the terminal uses the interference level information, etc. of the neighbor cells measured when configuring the CoMP set, only the PMI information of neighbor cells may be transmitted to the serving base station during the CoMP operation. In this case, the PMI ranking problem can be solved with less feedback overhead.

Meanwhile, the UE may transmit interference level information, etc. in addition to the PMI information of CoMP neighbor cells during the CoMP operation. In the case of the interference level information reported when the CoMP set is configured (or initial related information in the case of a CoMP system that does not form a CoMP set), the interference level that changes over time may not be accurately reflected. Accordingly, the terminal can solve this problem by transmitting the PMI information and the interference level information together. In this case, the terminal may transmit the PMI information and the interference level information in the same transmission period or may transmit the transmission period in a different manner.

In addition, the transmitted interference level information may be represented by various types of measurement values. This may be in the form of measurement values that the UE measures for the neighboring cell when configuring the CoMP set. For example, as described above, reference signal received power (RSRP), reference signal received quality (RSRQ), reference signal strength indicator (RSSI), propagation (PD) Delay), Carrier to Interference plus Noise Ratio (CINR) value or signal-to-interference for the neighboring cell measured when the neighboring cell used good PMI or bad PMI. Signal to Interference plus Noise Ratio (SINR) value, measured CINR value or SINR value when the adjacent cell does not use good PMI or bad PMI, or previously measured CINR value, or There is an improved CINR value or SINR value for the serving cell that indicates how much the channel state of the serving cell is improved by comparing the difference with the SINR value. In particular, the improved CINR value or SINR value may help determine the PMI rank in the adjacent cell. The UE measures before applying the measured CINR value or SINR value and the limit and / or recommended PMI when the neighbor cell does not use the bad PMI recommended or limited by the UE. A value corresponding to the difference between the CINR value or the SINR value may be measured and generated and transmitted to the base station. Adjacent cells receiving this information from the serving base station may be able to determine the degree of improvement of the channel state based on the difference value of the CINR value or SINR value, and thus may be easy to determine the PMI rank. As such, the UE may measure and report an interference level difference between the case where the PMI set reported to the neighbor cell is applied to the neighbor cell and the case where it is not applied to the serving base station.

In addition to the method of transmitting the PMI information and the interference level information (or related information) by the UE during the CoMP operation, a method of transmitting the PMI information and noise and interference variance information may be considered. That is, in order to help the CoMP neighbor cell determine the PMI rank, the UE transmits noise and interference variance information together with the PMI information, so that the CoMP neighbor cell can efficiently select the PMI that the CoMP neighbor cell wants to limit and / or recommend. Can be determined.

Hereinafter, a method of transmitting PMI information and noise and interference dispersion information to a serving base station by a feedback information transmission method will be described. First, the definition of feedback information to be measured and transmitted by the terminal will be described.

는 단말이 서빙 셀에 대해 선택한 PMI,

는 단말이 서빙 셀에 대해 측정한 잡음 및 간섭 분산(서빙 셀 신호의 세기를 의미할 수 있음),

는 단말이 CoMP 동작을 수행하는 각 인접 셀에 대해 제한 및/또는 추천하기를 원하 는 PMI,

는 CoMP 동작을 수행하지 않는 나머지 셀에 대한 잡음 및 간섭 분산,

는 CoMP 동작을 수행하는 각 인접 셀에서 제한 및/또는 추천 PMI가 적용되었을 때에 해당 인접 셀의 잡음 및 간섭 분산(해당 인접 셀의 신호의 세기 또는 간섭의 세기),

는 CoMP 동작을 수행하는 각 인접 셀에서 제한 및/또는 추천하는 PMI가 적용되었을 때와 적용되지 않을 경우의 해당 인접 셀의 잡음 및 간섭 분산 변화량(해당 인접 셀의 신호의 세기의 변화량 또는 간섭의 세기의 변화량)이다. 그리고

은 CoMP 동작을 수행하는 각 인접 셀에 대해 제한 PMI가 적용되었을 때의 해당 인접 셀의 잡음 및 간섭 분산,

은 각 CoMP 동작을 수행하는 인접 셀에 대해 추천 PMI가 적용되었을 때의 해당 인접 셀의 잡음 및 간섭 분산,

,...,

은 CoMP 동작을 수행하는 각 인접 셀에 대해 제한 PMI가 적용되었을 때와 적용되지 않을 때의 차이값(해당 인접 셀의 잡음 및 간섭 분산 변화량)이고,

,...,

은 각 CoMP 동작을 수행하는 인접 셀에 대해 추천 PMI가 적용되었을 때와 적용되지 않을 때의 차이값(해당 인접 셀의 잡음 및 간섭 분산 변화량)이고,

은 각 CoMP 동작을 수행하는 인접 셀에서 제한 및/또는 추천 PMI가 적용되었을 때에 단말이 측정할 수 있는 전체 셀에 대한 잡음 및 간섭 분산값이고,

은 각 CoMP 동작을 수행하는 해당 인접 셀에서 제한 및/또는 추천 PMI가 적용되었을 때와 적용되지 않았을 때에 단말이 측정할 수 있는 전체 셀에 대한 잡음 및 간섭 분산의 변화량을 말한다. 이하에서 보다 구체적으로 단말이 서빙 기지국으로 전송하는 잡음 및 간섭 분산값의 형태에 따라 구분되는 피드백 정보 전송 예들을 설명할 것이다.

PMI selected by the terminal for the serving cell,

Is noise and interference variance measured by the UE for the serving cell (which may mean the strength of the serving cell signal),

PMI that the terminal wants to limit and / or recommend for each neighbor cell performing CoMP operation,

Noise and interference variance for the remaining cells that do not perform CoMP operations,

Is the noise and interference variance (the strength of the signal or interference of the neighboring cell) of the neighboring cell when the limiting and / or recommended PMI is applied in each neighboring cell performing the CoMP operation,

Is the amount of change in the noise and interference variance of the neighboring cell when the limiting and / or recommended PMI is applied and not applied in each neighboring cell that performs the CoMP operation. Change amount). And

For each neighboring cell performing CoMP operation, the noise and interference variance of that neighboring cell when limiting PMI is applied,

The noise and interference variance of the neighboring cell when the recommended PMI is applied to the neighboring cell performing each CoMP operation,

, ...,

Is the difference between when the limiting PMI is applied and when it is not applied (the amount of change in noise and interference variance of that neighboring cell) for each neighboring cell performing CoMP operation,

, ...,

Is the difference between when the recommended PMI is applied and when it is not applied (the amount of change in noise and interference variance of the neighboring cell) for the neighboring cell performing each CoMP operation,

Is the noise and interference variance of the entire cell that the UE can measure when limiting and / or recommended PMI is applied in the neighboring cell that performs each CoMP operation,

The amount of change in noise and interference variance for the entire cell that the UE can measure when the limited and / or recommended PMI is applied and when not applied in the corresponding neighbor cell performing each CoMP operation. In more detail below, examples of transmission of feedback information classified according to the type of noise and interference variance values transmitted by the terminal to the serving base station will be described.

In the first method of transmitting noise and interference distribution information, a UE located at a cell boundary may select PMI information to be limited and / or recommended for CoMP neighbor cells that perform CoMP operation to a serving base station. Noise and interference variance information for the cell may be additionally transmitted.

에 추가하여, CoMP 인접 셀에 제한 또는 추천 PMI가 적용되었을 때의 잡음 및 간섭 분산값

을 추가로 전송할 수 있다(여기서 N은 CoMP 동작을 수행하는 셀 들 중 간섭을 주고 있는 셀의 인덱스를 의미).

값은 특정 CoMP 인접 셀에 국한된 잡음 및 간섭 분산값이다. 이 잡음 및 간섭 분산값에 기초하여 상기 특정 CoMP 인접 셀에 제한 또는 추천 PMI가 적용되었을 때와 적용되지 않았을 때의 잡음 및 간섭 분산 변화량을

와 같이 표현할 수 있다. 즉, 단말은 제한 및/또는 추천하는 PMI,

,

(또는

)을 서빙 기지국에 전송 하거나, 또는 제한 및/또는 추천하는 PMI,

,

및

모두를 전송할 수 있다.As another method for transmitting noise and interference distribution information, the UE wants to limit and / or recommend CoMP neighbor cells and noise and interference dispersion for other cells that do not perform CoMP operation.

In addition, noise and interference variances when limited or recommended PMI is applied to CoMP neighbor cells.

Can be additionally transmitted (where N denotes the index of the interfering cell among the cells performing the CoMP operation).

The value is a noise and interference variance that is localized to a particular CoMP neighbor cell. Based on this noise and interference variance value, the amount of change in noise and interference variance when the limited or recommended PMI is applied to the specific CoMP neighbor cell and when it is not applied

It can be expressed as That is, the terminal is limited and / or recommended PMI,

,

(or

PMI for transmitting or limiting and / or recommending to the serving base station,

,

And

You can send everything.

에 덧붙여, 특정 CoMP 인접 셀에 제한 PMI가 적용되었을 때의 잡음 및 간섭 분산값

와 추천하는 PMI가 적용되었을 때의 잡음 및 간섭 분산값

을 추가로 서빙 기지국에 전송할 수 있다. 또는, 단말은 서빙 기지국으로

와

값의 차이값인

을 전송할 수도 있다. 또는, 단말이 제한 및/또는 추천하는 PMI,

,

,

및

정보 모두를 서빙 기지국에 전송할 수도 있다. As another method, noise and interference variance values for the cells that perform the CoMP operation and / or the PMI and the other cells that do not perform the CoMP operation are recommended.

In addition, noise and interference variances when limiting PMI is applied to a particular CoMP neighbor cell.

And interference variances when and PMI is applied

May be further transmitted to the serving base station. Or, the terminal is a serving base station

Wow

The difference between

Can also be transmitted. Or, the PMI limited and / or recommended by the terminal,

,

,

And

All of the information may be sent to the serving base station.

에 덧붙여, 특정 CoMP 인접 셀에 대해 제한 또는 추천하는 PMI가 적용되었을 때의 전체 잡음 및 간섭 분산값

또는 상기

와 특정 CoMP 인접 셀에 대해 제한 또는 추천하는 PMI가 적용하기 전의 CoMP 동작을 수행하는 전체 셀에 대한 잡음 및 간섭 분산값과의 차이값인

을 서빙 기지국 으로 전송할 수 있다. 즉, 단말은

또는

값을 추가적으로 서빙 기지국에 전송할 수 있다. 여기서

값은 특정 CoMP 인접 셀에 국한된 잡음 및 간섭 분산 값이 아니라 단말에 영향을 미치는 전체 셀에 대한 잡음 및 간섭 분산값의 변화량을 의미한다. As another method for transmitting noise and interference distribution information, the UE limits noise and interference for cells performing CoMP operation and / or distributes noise and interference for other cells not performing CoMP operation

In addition, the overall noise and interference variance when the PMI is applied or limited for a particular CoMP neighbor cell.

Or above

And the difference between the noise and interference variances for all cells that perform CoMP operations before the PMI that is limited or recommended for a particular CoMP neighbor cell.

Can be transmitted to the serving base station. That is, the terminal

or

The value may additionally be transmitted to the serving base station. here

The value is not a noise and interference variance value limited to a specific CoMP neighbor cell but a change amount of noise and interference variance value for all cells affecting the terminal.

및 CoMP 동작을 수행하지 않는 나머지 셀에 대한 잡음 및 간섭 분산

에 추가하여

을 서빙 기지국으로 전송할 수 있다. 또는 단말은 특정 CoMP 인접 셀들에 대해 제한 및/또는 추천하는 PMI 정보와 CINR값인

,

를 전송할 수 있다. 이를 수신한 기지국은 협력 스케줄링/빔포밍을 수행할 때에 PMI 정보,

및

값에 기반하여

와 같이 CINR을 계산할 수 있다. 조인트 프로세싱을 수행할 시에는

와 같이 CINR을 계산할 수 있다. 이러한 전송 방법에 의하여, 단말은 서빙 기지국으로 전송하는 피드백 정보량을 감소시킬 수 있다. 또한, 단말이 제한 또는/및 추천하는 PMI가 적용되었을 때와 적용되지 않았을 때의 잡음 및 간섭 분산 변화량

을 이용해서 서빙 기지국으로 CINR 값을 보낼 수도 있다. 즉, 단말은 제한 및/또는 추천하는 PMI,

및

을 서빙 기지국에 전송할 수 있다. 또는, 단말이 제한 또는/및 추천하는 PMI,

,

및

을 서빙 기지국에 전송할 수 있다. As another method for transmitting noise and interference variance information, the UE restricts and / or recommends PMI and variance values of a serving cell to cells that perform CoMP operation.

And interference variance for the remaining cells that do not perform CoMP operation

In addition to

May be transmitted to the serving base station. Or, the UE is a PMI information and CINR value that is limited and / or recommended for specific CoMP neighbor cells.

,

Can be transmitted. The base station receiving the PMI information, when performing the cooperative scheduling / beamforming,

And

Based on the value

CINR can be calculated as When performing joint processing

CINR can be calculated as By this transmission method, the terminal can reduce the amount of feedback information transmitted to the serving base station. In addition, the amount of change in noise and interference variance when the terminal is limited and / or recommended PMI applied and when not applied

May also send a CINR value to the serving base station. That is, the terminal is limited and / or recommended PMI,

And

May be transmitted to the serving base station. Or, PMI recommended or restricted by the terminal;

,

And

May be transmitted to the serving base station.

에 기초하여, CoMP 동작을 수행하는 CoMP 인접 셀에 대한 정보를 추가적으로 전송할 수도 있다. 즉, 단말은 CoMP 동작을 수행하는 인접 셀에 대한 간섭 레벨 정보를 추가적으로 서빙 기지국으로 전송할 수 있다. 단말이 다중 셀의 신호 세기를 측정하는 때에 서빙 셀과 인접 셀 간에 참조심볼 자원 요소(reference symbol resource element)와 데이터 자원 요소의 충돌 등으로 인해 CoMP 동작을 수행하지 않는 인접 셀에 대한 잡음 및 간섭 분산값에 해당하는 값을 측정하여 구하기 어려울 수 있다. 따라서 단일 셀 동작에서 피드백 정보 전송을 위해 측정한 값들을 그대로 이용하여 다중 셀에서 CoMP 동작에서 피드백 전송을 함으로써, 다중 셀 기반으로 확장할 수 있으며 보다 효율적으로 피드백 정보를 전송할 수 있다. 결과적으로, 다중 셀 기반하에서 CoMP 인접 셀에 대한 간섭 레벨 측정에 따른 오버헤드, 피드백 정보 전송에 따른 오버헤드를 상당히 줄일 수 있다. Another noise and interference distributed information transmission method (Option 6), which is a CQI value transmitted from a terminal to a base station in a single cell operation

Based on the information, CoMP neighbor cell performing the CoMP operation may be additionally transmitted. That is, the UE may additionally transmit the interference level information for the neighbor cell performing the CoMP operation to the serving base station. Noise and interference distribution for neighboring cells that do not perform CoMP operation due to collision of reference symbol resource element and data resource element between serving cell and neighboring cell when UE measures signal strength of multiple cells It can be difficult to find and measure the value corresponding to a value. Therefore, by using feedback values measured for feedback information transmission in a single cell operation as it is in the CoMP operation in multiple cells, it can be extended based on a multi-cell and feedback information can be transmitted more efficiently. As a result, the overhead of measuring the interference level for CoMP neighbor cells and the overhead of transmitting feedback information on a multi-cell basis can be significantly reduced.

값에 서빙 셀의 신호의 세기로 정규화된 인접 셀의 신호의 세기

를 추가로 전송할 수 있다. 이를 통해 협력 스케줄링/빔포밍(CS/CB) 방식뿐만 아니라, 조인트 프로세싱(JP) 방식도 원활하게 수행할 수 있다.As an example, the UE is a CQI value for the serving cell based on a single cell.

Intensity of the signal in neighboring cells normalized to the strength of the signal in the serving cell

Can be further transmitted. Through this, not only the cooperative scheduling / beamforming (CS / CB) scheme but also the joint processing (JP) scheme may be smoothly performed.

The noise and interference distribution information transmission method described above is merely exemplary. The terminal may combine these noise and interference variance information in various forms and feed back various measured channel state information to the serving base station.

The following Table 1 is a table exemplifying measurement information values measured by a UE from a neighbor cell for transmission to a serving base station.

Measured value for the serving cell Measured value for adjacent cells performing CoMP operation Measured value for remaining cells that do not perform CoMP operation Option 1

,

(선택적임)

,

(Optional)

Option 2-1

,

(Optional)

or

Option 2-2

,

(Optional)

And

Option 3-1

,

(Optional)

(

) or (

, ...,

, ...,

)

Option 3-2

,

(Optional)

(

) And (

, ...,

, ...,

)

Option 4-1

,

(Optional)

or

Option 4-2

,

(Optional)

And

Option 5-1

,

or

Option 5-2

,

And

Option 6

Transmission of the measurement information shown in Table 1 is merely exemplary, and the terminal may provide feedback to the serving base station by combining various measured values in various forms.

3 is a view for explaining the concept of the UE and the base station performs a CoMP operation according to the present invention.

로 표현 가능하다. 단말이 셀 B에 대해 제한하기를 원하는 PMI인 W₂를 전송하고자 할 때, 셀 B가 W₂를 제한했을 때의 잡음 및 간섭 분산값인

를 함께 전송할 수 있다. 또는, 단말은 서빙 기지국으로 셀 B가 W₂를 제한하지 않았을 때의 잡음 및 간섭 분산값과 제한했을 때의 값과의 차이값인

을 추가적으로 보낼 수도 있다. 이때, 셀 B에 제한 PMI가 적용되었을 때의 잡음 및 간섭 분산값은

로, 추천 PMI가 적용되었을 때의 잡음 및 간섭 분산값은

로 나타낼 수 있고, 그 차이값은

로 나타낼 수 있다. 또한, 셀 B에 제한 또는 추천 PMI가 적용되었을 때의 전체 셀(셀 A 내지 셀 I)의 잡음 및 간섭 분산 값의 변화량을

로 나타낼 수 있다. A total of nine adjacent cells (cells A to I) exist in a terminal located at a cell boundary, and three neighboring cells (cell A, cell B, and cell C) have cooperative scheduling / beamforming or PMI restriction and / or Suppose you are involved in a recommendation. Consider a case in which cell boundary terminals belonging to cell A are subjected to interference from cell B and cell C, respectively, and want to limit W ₂ and W ₃ among PMIs for cell B and cell C, respectively. Here, the noise and interference variance values generated from the remaining six (Cell D to Cell I) that do not perform the CoMP operation

Can be expressed as When the UE wants to transmit W ₂ , which is a PMI that the UE wants to limit for cell B, it is a noise and interference variance value when cell B limits W ₂ .

Can be sent together. Or, the terminal is a serving base station, the difference between the noise and interference variance value when the cell B does not limit W ₂ and the value when limited

You can also send In this case, when the limit PMI is applied to the cell B, the noise and interference variance values are

The noise and interference variance values when the recommended PMI is applied

And the difference is

It can be represented as. In addition, the amount of change in the noise and interference variance values of all cells (cells A to I) when the limit or recommended PMI is applied to cell B

It can be represented as.

에 추가하여, 셀 B가 W₂를 제한했을 때의 잡음 및 간섭 분산값

및/또는 제한 PMI에 따른 잡음 및 간섭 분산값의 변화량인

을 더 포함하여 서빙 기지국으로 전송할 수 있다. 또한, 단말은 셀 B에 대하여 제한하고자 하는 PMI인 W_{2 ,} 및

외에

,

,

및

중에서 하나 이상의 값을 선택해서 함께 서빙 기지국으로 전송할 수 있다. The terminal may transmit various types of measurement values together with PMI information to the serving base station in various combinations. For example, the UE determines the noise and interference variance values generated from W ₂ , which is a PMI to be restricted for cell B, and the remaining six cells that do not perform CoMP operation.

In addition, noise and interference variances when cell B constrains W ₂

And / or the amount of change in noise and interference variance according to the limiting PMI,

It may further include transmitting to the serving base station. In addition, the UE W ₂ which is a PMI to be limited for the cell B _, and

In addition to

,

,

And

One or more values may be selected and transmitted together with the serving base station.

에 추가하여, 셀 C가 W₃를 제한했을 때의 잡음 및 간섭 분산값

또는 제한 PMI인 W₃ 에 따른 잡음 및 간섭 분산값의 변화량인

을 전송할 수 있다. 또한, 단말은 셀 C에 대하여 제한하고자 하는 PMI인 W_{3 ,} 및

에 추가하여

중 하나 이상의 값을 선택해서 함께 서빙 기지국으로 전송할 수 있다.Likewise, in case of cell C, the UE determines noise and interference variances generated from W ₃ , which is a PMI to be limited, and the remaining six cells that do not perform CoMP operation.

In addition, noise and interference variances when cell C limits W ₃

Or W ₃ , the limiting PMI Change in noise and interference variance according to

Can be transmitted. In addition, the UE W _{3 ,} which is a PMI to be limited for the cell C _, and

In addition to

One or more of the values may be selected and transmitted together with the serving base station.

을 구할 수 있고, 이는 PMI 순위 결정 문제를 해결하고 효율적인 협력 스케줄링/빔포밍 동작을 가능하게 해준다. Based on the noise and interference variance, the base station receives this information, which is the difference between when the PMI to be limited and / or recommended is applied in an adjacent cell and when it is not.

This solves the PMI ranking problem and enables efficient cooperative scheduling / beamforming operation.

When the terminal transmits the CSI feedback information to the serving base station, the terminal may normalize and transmit the CSI feedback information.

The UE may report recommended transmission characteristics (eg, CQI, PMI, RI) and other channel state information (CSI: Channel State Information, hereinafter called CSI) to the serving base station. In general, CSI feedback methods include quantization CSI feedback methods and analog CSI feedback methods. Regardless of the type of the CSI feedback scheme, the CSI reported by the UE to the serving cell may include a spatial channel matrix H (hereinafter, may be abbreviated as 'channel matrix H' or 'matrix H') or a spatial channel covariance matrix R (hereinafter, referred to as CSI feedback scheme). May be abbreviated as 'covariance matrix R' or 'matrix R', etc.). That is, the UE may transmit the spatial channel matrix H or the spatial channel covariance matrix R information as the CSI feedback information to the serving base station, and in addition to the spatial channel matrix H or the spatial channel covariance matrix R information, noise variance information (for example, , Interference level) may be additionally transmitted. That is, the UE may transmit noise and interference variance together with the spatial channel matrix H or the spatial channel covariance matrix R to the serving base station.

As such, the UE may normalize and transmit the CSI in order to transmit the CSI more accurately and efficiently. This normalization method may be performed in units of components of the channel matrix H and / or covariance matrix R, or may be performed on a vector of columns. Hereinafter, column normalized vector normalization will be described.

Normalization of a vector unit may be performed using a maximum value of norm values of respective columns of the matrix. The column with the largest norm value can normalize the noise and interference variance as well as the channel matrix H and / or covariance matrix R. After normalization, each column can be transferred in two ways.

First, the terminal may send a weighting factor of the norm value of each column normalized together with the CSI feedback information to the serving base station. The base station and the terminal share a codebook corresponding to one norm value (eg, norm = 1), and the serving base station transmits phase information through a channel matrix H and / or a covariance matrix R received from the terminal. The magnitude of the constellation may be known through a weighting coefficient of the norm value of each column received from the terminal. These weighting coefficient values may be transmitted as they are or may be transmitted in units of pre-quantized values. In addition, it can be expressed only by the change amount of the corresponding value based on the weighting factor 1.

Secondly, the base station and the terminal have codebooks corresponding to a plurality of norm values in advance, and not only the phase information but also the size information on the constellation through the channel matrix H and / or the covariance matrix R transmitted by the terminal. You can get it. The larger the number of predefined codebooks, the more accurate an estimation is possible.

A case where the terminal described above transmits the normalized channel matrix H and / or covariance matrix R will be described by way of example. Assume a 4x4 MIMO system with four transmission antennas of a base station and four receiving antennas of a terminal. The terminal may transmit a 4 × 4 channel matrix H expressed as in Equation 1 to the serving base station.

라고 가 정하자. 채널 행렬 H는 행렬의 각 열의 놈 값 중 최대값인 첫 번째 열의 놈 값인 2로 정규화될 수 있다. 이렇게 정규화된 각 열의 놈 값은 각각 1, 0.5, 0.5, 0.25가 되며, 단말은 1이 아닌 놈 값에 대한 가중 계수를 서빙 기지국에 전달할 수 있다.Where the norm values for each column

Let's say. The channel matrix H may be normalized to 2, which is the norm value of the first column, which is the maximum value among the norm values of each column of the matrix. The normalized values of the normalized columns are 1, 0.5, 0.5, and 0.25, respectively, and the terminal may transmit a weighting factor for the non-null value to the serving base station.

,

,

,

와 같이 4가지 놈 값에 대한 코드북이 있다고 가정하자. 우선 채널 행렬 H를 열의 놈 값들 중 가장 큰 놈 값으로 정규화를 수행할 수 있다. 상기 수학식 1의 예에서, 정규화 이후 첫 번째 열은

중 한 값에 매핑되고, 2, 3 번째 열은 각각

,

중 한 값에 각각 매핑될 수 있다. 마찬가지로, 4번째 열은

중 한 값에 매핑될 수 있다. 매핑 이후에는 단말은 해당 인덱스를 서빙 기지국으로 피드백해 줄 수 있다. In addition to the method of transmitting weighting coefficients to the serving base station, the terminal and the base station can know the channel matrix value by mapping the corresponding values with codebooks corresponding to various norm values in advance. E.g,

,

,

,

Suppose you have a codebook for four norm values, as in First, the channel matrix H may be normalized to the largest norm among the norm values of the column. In the example of Equation 1, the first column after normalization is

Are mapped to one of the values, and the second and third columns are

,

Each can be mapped to one of the values. Similarly, the fourth column

It can be mapped to either value. After mapping, the terminal may feed back the index to the serving base station.

The present invention can be extended to transmitting channel matrix H or covariance matrix R of each of a plurality of base stations and noise and interference variance values due to other base stations. In this case, the normalization may be performed using the largest norm among the columns of all channel matrices or the largest norm among the columns of all covariance matrices.

4 is a diagram illustrating a configuration of a preferred embodiment of a terminal device according to the present invention.

Referring to FIG. 4, a terminal device capable of performing a CoMP operation in a wireless communication system includes a processor 410, a memory unit 420, a transmission module 430, and a reception module 440.

Processor 410 includes a measurement module 411 module. The measurement module 411 may measure an interference level, noise, and interference variance value by using reference signals received from one or more adjacent cells.

The memory unit 420 may store various information received from the base station and values measured by the measurement module 411 for a predetermined period of time. The memory unit 420 may be replaced with another component such as a buffer (not shown).

The transmission module 430 includes the interference level information measured in the measurement module 411 or the noise and interference dispersion information, and the PMI (Precoding Matrix Index) information to be restricted or recommended for a specific neighbor cell performing the CoMP operation. It can transmit to the serving base station.

The receiving module 440 receives various signals and data such as control information and data from the serving base station.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The foregoing description of the preferred embodiments of the invention disclosed herein has been presented to enable any person skilled in the art to make and use the present invention. Although the above has been described with reference to the preferred embodiments of the present invention, those skilled in the art will understand that various modifications and changes can be made without departing from the scope of the present invention. For example, those skilled in the art can utilize each of the configurations described in the above-described embodiments in a manner of mutually combining them.

Accordingly, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are included as part of the detailed description in order to provide a thorough understanding of the present invention, provide an embodiment of the present invention and together with the description, illustrate the technical idea of the present invention.

1 is a diagram conceptually illustrating CoMP of an existing intra eNB and an inter eNB;

FIG. 2 is a diagram illustrating physical channels used in a 3rd generation partnership project (3GPP) Long Term Evolution (LTE) system, which is an example of a mobile communication system, and a general signal transmission method using the same;

3 is a view for explaining the concept of the UE and the base station performs a CoMP operation, and,

4 is a diagram illustrating a configuration of a preferred embodiment of a terminal device according to the present invention.

Claims (16)

In the wireless communication system in which at least one base station performs a coordinated multi-point (CoMP) operation, the terminal transmits feedback information, Transmitting Precoding Matrix Index (PMI) set information to a serving base station to limit or recommend for a particular neighbor cell performing the CoMP operation; And Signal strength gain that is a value corresponding to a difference between the strength or interference level of the signal calculated by applying the PMI set to the specific neighboring cell and the strength or interference level of the signal calculated when the PMI set information is not applied Transmitting a value or an interference level gain value to the serving base station. The method of claim 1, The signal strength or interference level may include a Signal to Interference plus Noise Ratio (SINR) value, a Reference Signal Received Power (RSRP), a Reference Signal Received Quality (RSRQ), and a reference signal. A method of transmitting CoMP feedback information, which is expressed by any one of a reference signal strength indicator (RSSI), a propagation delay (PD), and a carrier to interference plus noise ratio (CINR) value. In a method of transmitting feedback information by a terminal in a wireless communication system performing a coordinated multi-point (CoMP) operation, Measuring noise and interference variance values corresponding to signal strength or interference level using reference signals received from one or more adjacent cells; And Transmitting noise and interference variance information including the measured noise and interference variance values and precoding matrix index (PMI) information to be limited or recommended for a specific neighbor cell performing the CoMP operation to a serving base station; Including, CoMP feedback information transmission method. The method of claim 3, wherein The noise and interference variance information is a difference between a noise and interference variance value when the PMI applied to limit or recommend a specific neighbor cell performing the CoMP operation and a noise and interference variance value when not applied The CoMP feedback information transmission method comprising the first noise and interference dispersion information corresponding to. The method of claim 3, wherein The noise and interference variance information further includes second noise and interference variance information corresponding to noise and interference variance values for a cell not performing the CoMP operation. The method of claim 5, The noise and interference variance information further includes third noise and interference variance information corresponding to a value calculated by applying the limited or recommended PMI information to the specific CoMP neighbor cell. The method of claim 5, The noise and interference variance information is a noise and interference variance value before applying the limited or recommended PMI information to the specific CoMP neighbor cell, and a value corresponding to a difference between the noise and interference variance value when the fourth noise and interference variance is applied. Further comprising the information, CoMP feedback information transmission method. The method of claim 5, The noise and interference variance information corresponds to a noise and interference variance value calculated by applying the PMI desired to be limited to the specific CoMP neighbor cell and a noise and interference variance calculated by applying the PMI desired to be recommended. And further comprising fifth noise and interference variance information. The method of claim 5, The noise and interference variance information corresponds to a difference between a noise and interference variance calculated by applying a PMI desired to be limited to the specific CoMP neighbor cell and a noise and interference variance calculated by applying a PMI desired to be recommended. Further comprising sixth noise and interference variance information of the value. The method of claim 5, The noise and interference variance information further includes seventh noise and interference variance information corresponding to noise and interference variance values calculated by applying limited or recommended PMI information to all cells performing the CoMP operation. How to send information. The method of claim 5, The noise and interference variance information is based on a difference between the noise and interference variance values for all cells performing the CoMP operation before applying the received PMI to the specific CoMP neighbor cell, and the noise and interference variance values calculated by applying the CoMI operation. And a eighth noise and variance information, which is a corresponding value. The method of claim 5, The noise and interference variance information further includes noise and variance value information for a serving cell. The method of claim 12, The noise and interference variance information includes noise and interference variance values for a cell that does not perform the CoMP operation along with noise and variance values for the serving cell or the limited or recommended PMI information for the specific CoMP neighbor cell. The method of claim 1, further comprising information of the indicated value using the calculated noise and interference variance. The method of claim 12, The noise and interference variance information includes noise and interference variance values for cells that do not perform the CoMP operation, along with noise and variance values for the serving cell, or noise before applying the received PMI to the specific CoMP neighbor cell. The method of claim 1, further comprising information of a value indicated by using a value corresponding to a difference between the variance value and the noise and variance value calculated by applying. A method for performing a CoMP operation by a base station in a wireless communication system, Receive noise and interference distribution information including PMI (Precoding Matrix Index) information that the terminal wants to limit or recommend to the base station and signal strength or interference level of one or more adjacent cells measured by the terminal Making; And And generating rank information of the PMI for limiting or recommending to the terminal based on the received PMI information and the noise and interference variance information. A terminal device for transmitting feedback information in a wireless communication system performing a coordinated multi-point (CoMP) operation, A measurement module for measuring a noise and interference variance value including a strength or an interference level of the signal using reference signals received from one or more adjacent cells; And Transmission module for transmitting noise and interference variance information including the measured noise and interference variance values and PMI (Precoding Matrix Index) information to limit or recommend to a specific neighbor cell performing the CoMP operation to a serving base station A terminal device comprising a.

Images