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WO2011065763A2 - Procédé de transmission d'informations relatives à une matrice de précodage et dispositif utilisateur, et procédé de transmission de données à plusieurs dispositifs utilisateurs et à une station de base - Google Patents

Procédé de transmission d'informations relatives à une matrice de précodage et dispositif utilisateur, et procédé de transmission de données à plusieurs dispositifs utilisateurs et à une station de base Download PDF

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Publication number
WO2011065763A2
WO2011065763A2 PCT/KR2010/008397 KR2010008397W WO2011065763A2 WO 2011065763 A2 WO2011065763 A2 WO 2011065763A2 KR 2010008397 W KR2010008397 W KR 2010008397W WO 2011065763 A2 WO2011065763 A2 WO 2011065763A2
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WO
WIPO (PCT)
Prior art keywords
precoding matrix
user equipment
codebook
base station
information
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/KR2010/008397
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English (en)
Korean (ko)
Other versions
WO2011065763A3 (fr
Inventor
구자호
이욱봉
정재훈
임빈철
이문일
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LG Electronics Inc
Original Assignee
LG Electronics Inc
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Publication date
Priority claimed from KR1020100055385A external-priority patent/KR101717524B1/ko
Application filed by LG Electronics Inc filed Critical LG Electronics Inc
Priority to US13/511,596 priority Critical patent/US8989115B2/en
Priority to CN201080054267.9A priority patent/CN102640429B/zh
Publication of WO2011065763A2 publication Critical patent/WO2011065763A2/fr
Publication of WO2011065763A3 publication Critical patent/WO2011065763A3/fr
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B7/00—Radio transmission systems, i.e. using radiation field
    • H04B7/02—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas
    • H04B7/04—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas
    • H04B7/0413—MIMO systems
    • H04B7/0426—Power distribution
    • H04B7/0434—Power distribution using multiple eigenmodes
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B7/00—Radio transmission systems, i.e. using radiation field
    • H04B7/02—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas
    • H04B7/04—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas
    • H04B7/06—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station
    • H04B7/0613—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station using simultaneous transmission
    • H04B7/0615—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station using simultaneous transmission of weighted versions of same signal
    • H04B7/0617—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station using simultaneous transmission of weighted versions of same signal for beam forming
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B7/00—Radio transmission systems, i.e. using radiation field
    • H04B7/02—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas
    • H04B7/04—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas
    • H04B7/06—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station
    • H04B7/0613—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station using simultaneous transmission
    • H04B7/0615—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station using simultaneous transmission of weighted versions of same signal
    • H04B7/0619—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station using simultaneous transmission of weighted versions of same signal using feedback from receiving side
    • H04B7/0636—Feedback format
    • H04B7/0639—Using selective indices, e.g. of a codebook, e.g. pre-distortion matrix index [PMI] or for beam selection

Definitions

  • the present invention relates to a wireless communication system. Specifically, the present invention relates to a method and apparatus for reducing channel interference between multiple user devices when simultaneously transmitting signals to multiple users.
  • MIMO system refers to a system that increases the communication efficiency of data using a plurality of antennas.
  • the MIMO system can be divided into a spatial multiplexing technique and a spatial diversity technique according to whether the same data is transmitted.
  • Spatial multiplexing refers to a method in which data can be transmitted at high speed without increasing bandwidth of a system by simultaneously transmitting different data through a plurality of transmit antennas.
  • the spatial diversity scheme refers to a method in which transmit diversity can be obtained by transmitting the same data from a plurality of transmit antennas.
  • One example of such a space diversity technique is space time channel coding.
  • the MIMO system is divided into a single user MIMO (SU-MIMO) and a multi-user MIMO (MU-MIMO) according to how many users are allocated in the same time / frequency domain.
  • a section having a time / frequency domain may also be referred to as a resource region.
  • SU-MIMO one user may be allocated to one resource region
  • MU-MIMO multiple users may be allocated to one resource region.
  • the performance of SU-MIMO is good
  • the performance of MU-MIMO is good.
  • SU-MIMO and MU-MIMO may be classified into an open loop method and a closed loop method according to whether feedback of channel information from a receiving side to a transmitting side is performed.
  • the transmitting end transmits the information in parallel, and the receiving end repeatedly detects signals using ZF (Zero Forcing) and MMSE (Minimum Mean Square Error) methods and increases the amount of information by the number of transmitting antennas.
  • ZF Zero Forcing
  • MMSE Minimum Mean Square Error
  • STTC Space-Time Trellis Code
  • the receiver estimates a state of a wireless channel, and then transmits the estimated channel state to the transmitter in the form of appropriate feedback information.
  • the transmitter controls channel quality in consideration of the channel state obtained from the feedback information. That's the way. Closed loop schemes include TxAA (Transmit Antenna Array) schemes.
  • User equipments performing MU-MIMO in the same resource region operate in a group with each other, and channel performance is degraded due to channel interference between the user equipments. Therefore, a method for reducing channel interference between user equipments performing MIMO in the same resource region is required.
  • the present invention provides a method and apparatus for reducing channel interference between user equipments.
  • the present invention provides a method and apparatus that can reduce the feedback overhead by reducing the amount of feedback information that the user equipment transmits to the base station.
  • a method of transmitting precoding matrix information is provided.
  • a base station in any one of the plurality of user equipment for transmitting the precoding matrix information in a wireless communication system in which a plurality of user equipment simultaneously receives a signal transmitted from one base station, A transmitter for transmitting a signal to the transmitter; And a first precoding matrix, which is a precoding matrix for the specific user equipment, is determined from a predetermined codebook in receiving the signal, and at least one second preamble for another user equipment to be multiplexed in a predetermined resource region together with the specific user equipment.
  • the base station transmits data, wherein the corresponding user is determined in a predetermined codebook from the plurality of user equipments.
  • the first precoding matrix as first precoding matrix information indicating a first precoding matrix, which is a precoding matrix for a user equipment, and a precoding matrix for another user equipment to be multiplexed in a predetermined resource region together with the corresponding user equipment.
  • Second precoding matrix information indicating at least one second precoding matrix determined within a codebook subset of a given codebook associated with the matrix; Selecting a precoding matrix for transmission data of each user equipment to be transmitted on the predetermined resource region based on the first precoding matrix information and the second precoding matrix information; And precoding the transmission data of the respective user equipment into the selected corresponding precoding matrix, and transmitting the transmitted data to the respective user equipment in the predetermined resource region.
  • the base station in another aspect of the present invention, in a wireless communication system in which one base station simultaneously transmits signals to a plurality of user equipments, the base station is a precoding matrix for the corresponding user equipment determined in a predetermined codebook from the plurality of user equipments.
  • Information in a codebook subset of a predetermined codebook associated with the first precoding matrix as first precoding matrix information indicating one precoding matrix and a precoding matrix for another user equipment to be multiplexed in a predetermined resource region together with the corresponding user equipment.
  • An antenna configured to receive second precoding matrix information indicating the one or more second precoding matrices determined in U; And a precoder configured to precode the transmission data; Select a precoding matrix for transmission data of each user equipment to be transmitted on the predetermined resource region based on the first precoding matrix information and the second precoding matrix information, and transmit the corresponding transmission data to the selected precoding matrix. And a processor for controlling the precoder to precode and controlling the antenna to transmit the precoded transmission data to the respective user equipment in the predetermined resource region.
  • the second precoding matrix information may comprise an index of the second precoding matrix defined within the codebook subset.
  • the first precoding matrix information includes an index of the first precoding matrix defined within the predetermined codebook, or the codebook in codebook subsets belonging to the predetermined codebook. Information specifying a subset and an index of the first precoding matrix defined within the codebook subset.
  • the second precoding matrix information may include information designating one of patterns that prioritize the precoding matrices in the codebook subset.
  • information specifying one of the codebook subsets belonging to the predetermined codebook and one of the patterns defining the priority of precoding matrices in the codebook subset may include: It may be sent to the base station as first and second precoding matrix information.
  • the codebook subset may be configured with the first precoding matrix and a precoding matrix having a value below a predetermined correlation with the first precoding matrix.
  • a wireless communication system According to a wireless communication system according to embodiments of the present invention, there is an advantage in that channel interference can be reduced through feedback information transmitted between a user equipment and a base station.
  • FIG. 1 is a conceptual diagram illustrating a wireless communication system to which the present invention can be applied.
  • FIG. 2 is a block diagram illustrating components of a user equipment and a base station for carrying out the present invention.
  • FIG 3 illustrates a signal processing procedure using an orthogonal frequency division multiple access (OFDMA) scheme.
  • OFDMA orthogonal frequency division multiple access
  • FIG. 4 is a diagram illustrating an outline of a MIMO operation.
  • FIG. 5 is a diagram illustrating an example of a single user MIMO.
  • FIG. 6 is a diagram illustrating an example of a multi-user MIMO.
  • FIG. 7 is a conceptual diagram illustrating scheduling data for a plurality of users together for downlink transmission.
  • 8 is a table illustrating an example of a 4-bit codebook.
  • the wireless communication system includes at least one base station (BS) 11.
  • Each base station 110, 120, 130
  • Each base station provides a communication service for the user equipment (User Equipment, UE) located in a particular geographic area (commonly called a cell) (Cell A, Cell B, ..., Cell F) do.
  • the user device may be fixed or mobile, and various devices that communicate with the base station to transmit and receive user data and / or various control information belong to the same.
  • the user equipment may be a terminal equipment, a mobile station (MS), a mobile terminal (MT), a user terminal (UT), a subscriber station (SS), a wireless device, a personal digital assistant (PDA), a wireless modem ( It may be called a wireless modem, a handheld device, or the like.
  • a base station generally refers to a fixed station that communicates with a user equipment and / or another base station, and communicates with the user equipment and other base stations to exchange various data and control information.
  • the base station may be called in other terms such as an evolved-NodeB (eNB), a base transceiver system (BTS), an access point.
  • eNB evolved-NodeB
  • BTS base transceiver system
  • intra base stations 110 and 120 and inter base stations 130 there are intra base stations 110 and 120 and inter base stations 130.
  • An intra base station consists of several cells (or sectors). Cells sharing a base station such as a cell to which a specific user equipment belongs are cells corresponding to intra base stations 110 and 120 with respect to a cell to which the specific user equipment belongs, and cells belonging to other base stations are cells to which the specific user equipment belongs. With respect to the cells corresponding to the inter base station 130.
  • an intra base station may be referred to as a serving base station and an inter base station may be referred to as a neighbor base station for a specific cell.
  • a single cell MIMO user 160 communicates with one base station in one cell (sector), and a multi-cell MIMO user 150 located at a cell boundary has multiple base stations in multiple cells (sectors).
  • the multi-cell MIMO user 150 can communicate with eNB A in Cell A and Cell C and UE3 communicates with eNB B in Cell B and Cell C while UE1 communicates with eNB A in Cell B and Cell C.
  • FIG. 2 is a block diagram illustrating components of a user equipment and a base station for carrying out the present invention.
  • the user device 12 operates as a transmitter in uplink and as a receiver in downlink.
  • the base station 11 may operate as a receiver in uplink and as a transmitter in downlink.
  • the user equipment 12 and the base station 11 are antennas 500a and 500b capable of receiving information and / or data, signals, messages and the like, and transmitters 100a and 100b which control the antennas and transmit messages. And a receiver (300a, 300b) for receiving a message by controlling the antenna, and memory (200a, 200b) for storing a variety of information related to communication in the wireless communication system.
  • the user equipment 12 and the base station 11 control the components of the user equipment 12 or the base station 11, such as a transmitter, a receiver, a memory, etc., the processor 400a, 400b configured to perform the present invention. Each includes.
  • the transmitter 100a, the receiver 300a, the memory 200a, and the processor 400a in the user device 12 may be embodied as independent components by separate chips, and two or more of them may be one. It may be implemented by a chip.
  • the transmitter 100b, the receiver 300b, the memory 200b, and the processor 400b in the base station 11 may each be implemented as separate components by separate chips, and two or more are one. It may be implemented by a chip of.
  • the antennas 500a and 500b transmit a signal generated by the transmitters 100a and 100b to the outside, or receive a radio signal from the outside and transmit the signal to the receivers 300a and 300b.
  • a transmission / reception module supporting a multi-input multi-output (MIMO) function for transmitting and receiving data using a plurality of antennas may be connected to two or more antennas.
  • MIMO multi-input multi-output
  • Processors 400a and 400b typically control the overall operation of various modules within user equipment 12 or base station 11.
  • the processor 400a or 400b includes various control functions for performing the present invention, a medium access control (MAC) frame variable control function according to service characteristics and a propagation environment, a power saving mode function for controlling idle mode operation, and a hand. Handover, authentication and encryption functions can be performed.
  • the processors 400a and 400b may also be referred to as controllers, microcontrollers, microprocessors, microcomputers, or the like. Meanwhile, the processors 400a and 400b may be implemented by hardware or firmware, software, or a combination thereof.
  • firmware or software When implementing the present invention using hardware, application specific integrated circuits (ASICs) or digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), FPGAs ( field programmable gate arrays) may be provided in the processors 400a and 400b.
  • ASICs application specific integrated circuits
  • DSPs digital signal processors
  • DSPDs digital signal processing devices
  • PLDs programmable logic devices
  • FPGAs field programmable gate arrays
  • the firmware or software may be configured to include a module, a procedure, or a function for performing the functions or operations of the present invention, and configured to perform the present invention.
  • the firmware or software may be provided in the processors 400a and 400b or may be stored in the memory 200a and 200b to be driven by the processors 400a and 400b.
  • Transmitters 100a and 100b perform predetermined coding and modulation on signals and / or data scheduled from the processors 400a and 400b and then transmitted to the antennas 500a and 500b. do.
  • the transmitters 100a and 100b convert the data sequence to be transmitted into K signal sequences through demultiplexing, channel encoding, and modulation.
  • the K signal strings are transmitted through the transmit antennas 500a and 500b through a transmitter in the transmitter.
  • the transmitters 100a and 100b and the receivers 300a and 300b of the user device 12 and the base station 11 may be configured differently according to a process of processing a transmission signal and a reception signal.
  • FIG 3 illustrates a signal processing procedure using an orthogonal frequency division multiple access (OFDMA) scheme.
  • OFDMA orthogonal frequency division multiple access
  • the transmitter in the user equipment or the base station may transmit one or more code words.
  • Each of the one or more codewords may be scrambled by the scrambling module 301 and modulated into a complex symbol by the modulation mapper 302.
  • the layer mapper 303 maps the complex symbols to one or more transmission layers, and the precoder 304 multiplies the complex symbols of the transmission layers by a predetermined precoding matrix W selected according to channel conditions and outputs the complex symbols for each antenna.
  • the precoder 304 may use both a codebook method and a non-codebook method.
  • the complex symbols for each antenna are mapped to time-frequency resource elements to be used for transmission by the resource element mapper 305, and the complex symbols for each antenna mapped to the time-frequency resource elements are OFDM signal generators.
  • 306 is converted into an OFDM signal for each antenna port and transmitted to each antenna port.
  • the OFDMA scheme is widely used for downlink transmission because frequency efficiency and cell capacity can be increased.
  • the OFDMA scheme may be used for uplink transmission.
  • FIG. 4 is a diagram illustrating an outline of a MIMO operation.
  • the base station has a precoding matrix W, and there is a channel matrix H between the base station and the user equipment (UE).
  • the user equipment estimates such a channel matrix H through a reference signal (RS) from the base station, and generates and feeds back precoding matrix information that helps the base station set the precoding matrix W well.
  • RS reference signal
  • CQI Channel Quality Indicator
  • RI Rank Indicator
  • the precoding matrix is selected based on the codebook, but the user equipment actually reduces the amount of feedback information because the user equipment designates the precoding matrix by feeding back only the index of the codebook.
  • the user equipment selects a precoding matrix estimated to minimize channel interference with respect to the user equipment among codebooks that designate 'L' precoding matrices, and indicates a precoding matrix indicator.
  • PMI Precoding Matrix Indicator
  • the base station selects a precoding matrix based on the PMI, multiplies the data to be transmitted to the user equipment, and transmits the precoding matrix to the user equipment.
  • Table 1 shows an example of a codebook for 2-port antenna transmission
  • Table 2 shows an example of a codebook for 4-port antenna transmission.
  • Table 1 is called a 2-bit codebook because it can specify a codebook index as 2 bits
  • Table 2 is called a 4-bit codebook because it can specify a codebook index as 4 bits.
  • 2-bit and 4-bit codebooks are taken as examples, 8-bit, 16-bit, and 64-bit codebooks may be further defined as the number of antenna ports increases.
  • the codebooks of Tables 1 and 2 designate a precoding matrix according to the LTE standard, and a different form of precoding matrix may be designated according to the wireless communication system standard.
  • embodiments of the present invention will be described using a 4-bit codebook as an example for convenience of explanation, but it is obvious that the present invention can be similarly applied to codebooks of other bits.
  • the base station selects a precoding matrix W in a codebook defined between the base station and the user equipment based on the PMI fed back from the user equipment, and performs precoding by multiplying the selected precoding matrix W by the complex symbols of the transmission layer. .
  • FIG. 5 is a diagram illustrating an example of a single user MIMO
  • FIG. 6 is a diagram illustrating an example of a multiuser-MIMO.
  • single-user MIMO is a structure in which a plurality of different transport streams transmitted by a base station are all transmitted to one user.
  • one transmitter and one receiver constitute a MIMO channel.
  • one user can receive all signals. That is, only data for one user is scheduled in the same time / frequency domain.
  • multi-user MIMO transmits a plurality of different transport streams transmitted by a base station to a plurality of users.
  • one transmitter and several receivers combine to form a MIMO channel. That is, data may be scheduled together for multiple users in the same time / frequency domain.
  • FIG. 7 is a conceptual diagram illustrating scheduling data for a plurality of users together for downlink transmission.
  • the scheduler may schedule data of specific users to be transmitted together based on precoding matrix information from the user equipment or feedback information such as CQI and RI. Referring to FIG. 7, the scheduler may schedule transmission data for user equipment 0 (UE 0 ) to user equipment K (UE K ) in the same time / frequency domain.
  • the processor 400b in the base station may be configured to perform a function of a scheduler. It is also possible that the control station connected to the base station has a scheduler and transmits schedule information to the base station.
  • the scheduler may be configured as an independent module and provided in the base station or the control station.
  • each of the plurality of user equipments has a CQI indicating the quality of a channel formed between itself and the base station, and a PMI for minimizing channel interference affecting itself.
  • the RI is fed back to the base station indicating how many signal streams can be transmitted on the channel at the same time.
  • the CQI, PMI, RI, etc. fed back from the user equipment to the base station indicate the state of the channel formed between the user equipment and the base station, and is called channel state information.
  • the base station selects a transmission channel or improves the quality of the transmission channel. It is also used to control channel quality control information (channel quality control information).
  • the base station selects user equipments to be scheduled together based on PMIs, CQIs, RIs, etc. sent by the plurality of user equipments, and sets a precoding matrix W based on PMIs sent by the user equipments to be scheduled together.
  • the precoding matrix indicated by the PMI for minimizing the channel interference affecting the specific user equipment may not be selected as the final precoding matrix by the PMI transmitted by other user equipment scheduled together.
  • the best precoding matrix W 0 is applied to user equipment 0 by PMIs transmitted by other user equipments. It may not be selected.
  • a base station when a base station receives several PMIs from a plurality of user equipments, the base station arbitrarily selects a matrix for precoding data of user equipments to be scheduled together based on these PMIs.
  • User device 0 may include something that is not the best precoding matrix. In this case, the interference by the channel of the other user equipments scheduled together may not be sufficiently reduced, resulting in degradation of downlink signal transmission performance to the user equipment 0.
  • channel interference occurs between transmission data of different user equipments transmitted together in the predetermined resource region, thereby degrading performance of a wireless communication system. Will result.
  • one embodiment of the present invention is considered in the case that the data for a plurality of user equipment is scheduled together in the same time / frequency domain, only the information specifying the best precoding matrix for the transmission data for the user equipment Rather, information is transmitted to the base station together with information specifying a precoding matrix to be applied to transmission data of another user equipment scheduled together with the corresponding user equipment.
  • a specific user equipment transmits feedback information to a base station
  • a precoding matrix to be applied to transmission data of a specific user equipment will be referred to as a best precoding matrix
  • the precoding matrix to be used by the other user equipment will be described as a best companion.
  • the user equipment feeds back information indicating the best companion to the base station, as the size of the codebook increases, the number of precoding matrices to be evaluated by the processor increases, and thus the processor and processing having higher processing performance. Higher memory capacity is required of the user equipment to temporarily store data.
  • FIG. 8 is a table illustrating an example of a 4-bit codebook to describe embodiments of the present invention.
  • a 4-bit codebook is described as an example, but it is obvious that embodiments of the present invention can be equally applied to codebooks of other bits.
  • a base station of a serving cell to which a specific user equipment currently belongs is specified in addition to information specifying a precoding matrix that the base station wants to apply to transmission data of the specific user equipment. Transmitting information specifying a precoding matrix for transmission data of another user equipment to be transmitted, that is, information specifying a best companion, to the base station, and selecting the best companion from all precoding matrices in a base codebook. Instead, the best companion is obtained from a codebook subset consisting of matrixes having a constant relationship with a precoding matrix (hereinafter, best precoding matrix) to be applied to transmission data of the specific user equipment among precoding matrices of a basic codebook. It selects and transmits information about the PMI designating this to the base station.
  • best precoding matrix a codebook subset consisting of matrixes having a constant relationship with a precoding matrix
  • the codebook subset is composed of matrices having a constant relation with the best precoding matrix, when a base station cannot select the best precoding matrix designated by a specific user equipment, the codebook subset is arbitrarily selected from the entire precoding matrix of the basic codebook. There is an advantage that the precoding matrix selected in the codebook subset reduces the risk of worsening channel interference between user equipments rather than the precoding matrix.
  • the user equipment and the base station may consist of precoding matrices indicated by codebook indices within a range from the best PMI specifying the best precoding matrix, or may be composed of precoding matrices orthogonal to the best PMI.
  • An algorithm may be configured of precoding matrices having a value less than or equal to a predetermined correlation, or a codebook subset is determined from precoding matrices that are advantageous for reducing channel interference for each transmission mode determined according to a predetermined criterion.
  • the base station and the user equipment select precoding matrices designated by n codebook indexes, m lines, or l codebook indexes indicated by the PMI transmitted by the user equipment as the codebook subset.
  • the processor 400a generates precoding matrix information for designating the best precoding matrix and the best companion, and controls the transmitter 100a and the antenna 500a in the user equipment to transmit the precoding matrix information to the base station. Can be sent to.
  • the processor 400b of the base station selects the best precoding matrix for the specific user equipment and the user equipment (s) multiplexed in a predetermined resource region together with the specific user equipment.
  • the precoding matrix (s) for. For example, assuming that the precoding matrix W 3 corresponding to the codebook index 3 is the best precoding matrix for a specific user equipment, the user equipment and the base station are each n lines after the matrix designated by the codebook index 3, for example. And a set ⁇ W 1 , W 2 , W 3 , W 4 , W 5 ⁇ including two precoding matrices as a codebook subset corresponding to the best precoding matrix.
  • the codebook subset ⁇ W 3 , W 4 , W 5, W 6 ⁇ It may be determined as a codebook subset for the specific user equipment.
  • a set of orthogonal precoding matrices is formed. It may be set as a codebook subset.
  • a precoding matrix for minimizing channel interference between a channel of a specific user equipment and a channel of another user equipment is likely to have an orthogonal relationship with the precoding matrix that provides the best signal to the specific user equipment. That is, the smaller the best precoding matrix and correlation with respect to the specific user equipment, the more the channel interference of the other user equipment with respect to the channel of the specific user equipment may be minimized.
  • the processor 400a of the user equipment determines which of the precoding matrices in the basic codebook is the best precoding matrix for the user, and the best companion is the best precoding matrix. It can be configured to determine among the matrices that are orthogonal.
  • the user equipment processor 400a may control the transmitter 100a and the antenna 500a of the user equipment to transmit the precoding matrix information specifying the best precoding matrix and the best companion to the user equipment.
  • the set ⁇ W x , W y , and W z ⁇ consisting of them is codebook subset. It is also possible to specify. 2 and 4, a codebook subset according to a specific transmission mode may be predefined between a user equipment and a base station, and the processor 400a of the user equipment may use a codebook subset for itself from a codebook subset corresponding to the specific transmission mode. The best precoding matrix and the best companion for another user equipment may be determined, and the transmitter 100a and the antenna 500a may be controlled to transmit the information indicating the best precoding matrix and the best companion to the base station.
  • codebook subsets are defined by precoding matrices in orthogonal relations.
  • codebook subsets defined by other criteria as well as codebook subsets of orthogonal precoding matrices.
  • the precoding matrices designated by codebook indices 0 to 3 are orthogonal to each other
  • the precoding matrices designated by codebook indices 4 to 7 are orthogonal to each other
  • codebook indices 8 to 11 The precoding matrices specified by orthogonal to each other may be orthogonal to each other
  • the precoding matrices designated by the codebook indexes 12 to 15 may be orthogonal to each other.
  • the user equipment selects the best companion from the precoding matrices of codebook indexes 0, 2, and 3 that are orthogonal to each other, and selects the best
  • the best companion PMI specifying the companion can be transmitted to the base station along with the best PMI specifying the best precoding matrix.
  • the base station selects the best PMI that specifies the best precoding matrix sent by the user equipment 0 and the best companion PMI that specifies the best companion, and the best PMI and the best companion PMI sent by other user equipments to be scheduled together in a predetermined resource region.
  • each precoding matrix for data to be transmitted to these user equipments can be selected.
  • the number of best companions selected by the user equipment may depend on the number of user equipments that can be scheduled together or the number of signal streams that can be scheduled together.
  • the number of selectable best companions depends on the number of user equipments that can be scheduled together or the number of signal streams, for example, when user 0 can receive three signal streams at the same time. ) it is '3', the user equipment 0 to of the best precoding matrix W 0, W 2, which is orthogonal to W 1 W 3 determines two, best Compassion, the best precoding matrix W 1 and best Information specifying two companions may be fed back to the base station.
  • the processor 400a of the user equipment is the best precoding matrix W for itself among the precoding matrices in the codebook stored in the user equipment processor 400a itself or the memory 200a of the user equipment.
  • the precoding matrix information for sequentially specifying W 1 , W 3 , and W 0 may be transmitted to the base station.
  • the number of best companions indicates the number of signal streams that can be simultaneously transmitted by the user equipment.
  • the same effect as that of transmitting RIs with PMI can be obtained.
  • the processor 400a of the user equipment may not generate the RI, and the user may not transmit the RI to reduce the feedback overhead even if the user equipment generates the RI. It is also possible to control the device transmitter 100a.
  • the base station processor 400b may check the number of precoding matrices designated by the user equipment, which precoding matrices are designated, and the number of streams each user equipment can receive from the feedback precoding matrix information.
  • the rank it is also possible to select a certain number of best companions and feed back the information indicating these to the base station. For example, if the number of precoding matrices that a user equipment can specify is three, even if the rank of the user equipment is '2', the best precoding matrices and the two best companions are determined in order of preference. It is also possible to feed back information indicating the precoding matrix to the base station.
  • the user device 0 selected from the 4-bit codebook 0 is selected from the best precoding matrix W 1 , the best companion W 3 selected from the subset of codebooks constant with W 1 , and the next preferred best year W.
  • An example of selecting 0 and feeding back information indicating these to the base station will be described as an example. That is, the user device 0 selects a precoding matrix W 1 that the base station wants to apply to the transmission data when transmitting data to the user device 0, and there are other user devices to be multiplexed in a predetermined resource region together with the user device 0.
  • precoding matrix information In consideration of the case, a case in which a best coding year for minimizing interference on the user device 0 is selected in order of W 3 and W 0 is used as a precoding matrix that is desired to be applied to transmission data of another user device.
  • PMI K the PMI specifying the precoding matrix W K.
  • precoding matrix information the information which designates the best and best companion year is collectively demonstrated as precoding matrix information.
  • the user equipment may transmit, as the precoding matrix information, the PMI for each of the best companions selected from the best precoding matrix and a codebook subset having a constant relation with the best precoding matrix.
  • the user equipment 0 may transmit to the base station in the order of PMI 1 for the precoding matrix W 1 , PMI 3 for the precoding matrix W 3 , and PMI 0 for the precoding matrix W 0 .
  • the processor 400a of the user equipment determines PMI 1 for the best precoding matrix W 1 , PMI 3 for the first best companion W 3 , and PMI 0 for the second best companion W 0 . It can control the base station transmitter (100a) to transmit.
  • the user equipment and the base station may predetermine a pattern according to the priority of the matrixes of the codebook subset, and transmit the information specifying the user equipment preferred pattern as the precoding matrix information to the base station together with the information specifying the best precoding matrix. have.
  • the best precoding matrix for user equipment 0 is W 1 and the order of the preferred best companion, that is, the order of the precoding matrix that minimizes interference to the user equipment by other user equipment is W 2 , W O , W If the order is 3 , the user equipment 0 can feed back the base station with 4 bits of PMI designating the best precoding matrix W 1 and 3 bits of pattern index designating the best companions W 2 , W O , and W 3 in that order.
  • the best precoding matrix of user equipment 1 is W 2
  • the best companion pattern for user equipment 1 will be determined by combining W 0 , W 1 , and W 3 , and the best precoding of user equipment 3 If the matrix belongs to a codebook subset different from W 1 , the pattern of the precoding matrix for user equipment 3 will be determined by the combination of the precoding matrices of the other codebook subset.
  • the processor of the user equipment 0 configures the precoding matrix information using a total of 7 bits of the PMI bit string '0001' and the pattern index bit string '010'.
  • the transmitter and the antenna of the user equipment 0 may be controlled to feed back the precoding matrix information to the base station.
  • the antenna of the base station receives the precoding matrix information, and the processor of the base station can know the best precoding matrix W 1 for user equipment 0 and the precoding matrix pattern group associated with the W 1 by the first 4 bits. Then, it can be seen that the rank of the best companion for the user equipment 0 among the precoding matrix patterns associated with the W 1 is in the order of W 2 , W O , and W 3 by 3 bits.
  • the processor of the base station selects precoding matrices to be applied to user equipments to be scheduled together in a predetermined resource region based on 7 bits of precoding matrix information transmitted from user equipment 0 and precoding matrix information transmitted from other user equipments. can do.
  • the base station processor 400b may control the transmitter 100b of the base station to precode data for the corresponding user equipment by applying the selected precoding matrices.
  • the base station processor 400b may control the base station transmitter 100b to transmit data of the precoded user equipments in the predetermined resource region.
  • the user equipment and the base station predetermine patterns according to the priorities of the matrixes of the codebook subset, and the base station uses the information indicating the codebook subset including the preferred pattern of the user equipment and the information indicating the preferred pattern as the precoding matrix information. Can also be sent to.
  • the codebook subset to which the best precoding matrix W 1 of user equipment 0 belongs is ⁇ W O , W 1 , W 2 , W 3 ⁇
  • four precoding matrices are sequentially selected from the codebook subset, and a total of 24 codebook subsets are selected.
  • a total of 2 bits are required to indicate the codebook subset ⁇ W O , W 1 , W 2 , W 3 ⁇ among the total of 4 codebook subsets, and a total of 5 bits to indicate the preferred pattern of the user equipment among the total 24 patterns. Is needed.
  • the codebook subset ⁇ W O , W 1 , W 2 , W 3 ⁇ is the first codebook subset
  • user equipment 0's preferred best precoding matrix is W 1
  • the best companions are W 2 , W O , and W 3 . 2 and 8 and Table 4
  • the processor of the user equipment 0 has a bit string '00' 2 bits and the precoding matrix W 1 , W 2 , W O , W 3 that designate the codebook subset.
  • the precoding matrix information may be configured using 5 bits of the pattern index bit string '01000', which specifies the order, and the precoding matrix information may be fed back to the base station by controlling the transmitter and the antenna of the user device _0.
  • the base station antenna and the receiver receive the 7-bit precoding matrix information transmitted from the user equipment 0, and the processor of the base station is a precoding matrix preferred by the user equipment 0 by the preceding two bits of the precoding matrix information.
  • the codebook subsets ⁇ W O , W 1 , W 2 , W 3 ⁇ belong to each other, and the next 5 bits indicate the best precoding matrix for user equipment 0 is W 1 , and the preferred best companion is W in order. It can be seen that 2 , W O , W 3 .
  • the processor of the base station may be scheduled together in a predetermined resource region based on 7 bits of precoding matrix information transmitted from user equipment 0 and precoding matrix information transmitted from other user equipments, that is, multiplexed together in the predetermined resource region.
  • a precoding matrix to be applied to each user device can be selected.
  • the base station processor selects a precoding matrix to be applied to the transmission data of the user equipment 0 based on the best precoding matrix W 1 feedbacked by the user equipment 0 and the best companion transmitted by the other user equipment.
  • Precodings to be applied to the transmission data of each of the other user devices may be selected based on the best companion designated by the user device 0 and the corresponding best precoding matrix fed back by the other user devices.
  • the base station processor may control the transmitter 100b of the base station to precode transmission data of the corresponding user equipment multiplexed in the predetermined resource region by applying the selected precoding matrix.
  • the base station processor may control the base station transmitter 100b to simultaneously transmit transmission data of user equipments scheduled together in the predetermined resource region to the user equipments through the predetermined resource region.
  • the processor of user equipment 0 has the best precoding matrix W of 2 bits that designate the first codebook subset and the four precoding matrices of the first codebook subset.
  • Preferred precoding matrix in the first codebook subset using a total of 8 bits, including 2 bits specifying 1 , 2 bits specifying the best best companion W 2 , and 2 bits specifying the next best best year W O. Can be specified in order. That is, the processor of the user equipment 0 configures 8-bit precoding matrix information, and transmits the precoding matrix information to the base station by controlling the transmitter and the antenna of the user equipment 0. A base station receives the 8-bit precoding matrix information transmitted from the user equipment 0 through an antenna and a receiver, and the processor of the base station selects the best value for the user equipment 0 by the first two bits of the precoding matrix information.
  • the codebook subset ⁇ W O , W 1 , W 2 , W 3 ⁇ to which the precoding matrix and the Best Companion belong, can be seen, and the next 2 bits indicate that the best precoding matrix is W 1 , and the next 2 bits It can be seen that the first best companion W 2 , and then the second best companion is W O by the next 2 bits.
  • the processor of the base station selects precoding matrices to be applied to user equipments to be scheduled together in a predetermined resource region based on the 8 bits of the precoding matrix information transmitted from user equipment 0 and the precoding matrix information transmitted from other user equipments. Each can be selected.
  • the base station processor may control the transmitter 100b of the base station to precode the transmission data of the user equipments scheduled together using the selected corresponding precoding matrix.
  • the base station transmitter 100b may transmit the precoded transmission data to the predetermined user equipments through the predetermined resource region under the control of the base station processor 400b.
  • Information for specifying a predetermined codebook subset and information specifying a precoding matrix in the codebook subset between the user equipment and the base station is transmitted to the base station, but the best companions are the remaining matrices except the precoding matrix that has already been prioritized in the codebook subset. It is also possible to transmit the precoding matrix information to the base station in the form of choosing.
  • the best precoding matrix W 1 of user equipment 0 is included in the first codebook subset ⁇ W O , W 1 , W 2 , W 3 ⁇ , and the best companion wants to apply it to the transmission data of other user equipments.
  • the processor of user equipment 0 has the best precoding of the two bits that designate the first codebook subset of the four codebook subsets and the four precoding matrices of the first codebook subset. 2 bits specifying the matrix W 1 , 2 bits specifying the first best companion W 2 of the remaining three precoding matrices, and 7 bits total, 1 bit specifying the next best companion W O of the other two precoding matrices.
  • Precoding matrix information for sequentially designating a preferred precoding matrix and a best companion in the first codebook subset may be configured using.
  • the processor of the user device 0 may control the transmitter and the antenna to feed back the precoding matrix information to the base station.
  • a base station receives the 7-bit precoding matrix information transmitted from the user equipment 0 through an antenna and a receiver, and transmits the received 7-bit precoding matrix information to the processor of the base station.
  • the codebook subset ⁇ W O , W 1 , W 2 , W 3 ⁇ to which device 0 prefers the precoding matrix and the best companion (s) belongs, and the next 2 bits are the best precoding of the user device 0.
  • the matrix W 1 can be known, and the next two bits show that the first best companion is W 2 , and the next best bit is W 0 .
  • the processor of the base station selects precoding matrices to be applied to user equipments to be scheduled together in a predetermined resource region based on the 7 bits of the precoding matrix information transmitted from user equipment 0 and the precoding matrix information transmitted from other user equipments. Each can be selected.
  • the base station processor may control the transmitter 100b of the base station to precode data about the user equipments scheduled together by applying the selected corresponding precoding matrices, respectively.
  • the base station transmitter 100b may transmit the precoded transmission data to the predetermined user equipments through the predetermined resource region under the control of the base station processor 400b.
  • the user equipment can transmit the PMI specifying the best precoding matrix and the information specifying the best companion in the codebook subset to which the PMI belongs to the base station as the precoding matrix information.
  • the best precoding matrix of user equipment 0 is W 1
  • the codebook subset containing W 1 is ⁇ W O , W 1 , W 2 , W 3 ⁇ and user 0 is the preferred best companion.
  • the processor on the user equipment 0 is the codebook subset that belongs to 4 bits and W 1 that specifies W 1 in the 4-bit codebook ⁇ W O , W 1 , W 2 , W In 3 ⁇
  • a total of 8 bits of 2 bits designating W 2 and 2 bits designating W O are configured as precoding matrix information, and the transmitter and antenna of the user equipment 0 are controlled to transmit the precoding matrix information to the base station.
  • the base station receives the 8-bit precoding matrix information through the antenna and the receiver, and it can be seen that the best precoding matrix W 1 for user equipment 0 from the previous 4 bits, whereby W 1 is determined by W 1 . It can be seen that the codebook subset ⁇ W O , W 1 , W 2 , W 3 ⁇ belonging to. In addition, it can be seen that the next best bit is W 2 by the next two bits, and the next best year is W 0 by the next two bits.
  • the processor of the base station may select precoding matrices to be applied to user equipments to be scheduled together based on the 8 bits of the precoding matrix information transmitted from user equipment 0 and the precoding matrix information transmitted from other user equipments. have.
  • the base station processor may control the transmitter 100b of the base station to precode data about the user equipments scheduled together by applying the selected corresponding precoding matrices, respectively.
  • the base station transmitter 100b may transmit the precoded transmission data to the predetermined user equipments through the predetermined resource region under the control of the base station processor 400b.
  • the user equipment transmits the PMI designating the best precoding matrix and the information specifying the best companion in the codebook subset to which the PMI belongs to the base station as the precoding matrix information, but the best comparables already have priority in the codebook subset. It is also possible to transmit the precoding matrix information to the base station in a form of selecting from the rest of the matrix except the predetermined precoding matrix.
  • the best precoding matrix of user equipment 0 is W 1
  • the codebook subset containing W 1 is ⁇ W O , W 1 , W 2 , W 3 ⁇ and user 0 is the preferred best companion.
  • the processor on the user equipment 0 is the codebook subset that belongs to 4 bits and W 1 that specifies W 1 in the 4-bit codebook ⁇ W O , W 1 , W 2 , W Of the three precoding matrices except W 1 , 2 bits designating W 2 , and one bit designating W O among two precoding matrices except W 1 and W 2 . It can transmit to the base station as.
  • the base station receives the 7-bit precoding matrix information through a receiver and an antenna, so that the best precoding matrix W 1 for the user equipment 0 from the previous 4 bits and the codebook subset ⁇ W O , W 1 to which W 1 belongs. , W 2 , W 3 ⁇ . Further, that a ⁇ W O, W 2, W 3 ⁇ Best Compassion years W 2 of by the next two bits, ⁇ W 0, W 3 ⁇ yi W 0 in the following Best Compassion of by the next one bit of the It can be seen that.
  • the processor of the base station may select precoding matrices to be applied to user equipments to be scheduled together based on the 7 bits of the precoding matrix information transmitted from user equipment 0 and the precoding matrix information transmitted from other user equipments. have.
  • the base station processor may control the transmitter 100b of the base station to precode data about the user equipments scheduled together by applying the selected corresponding precoding matrices, respectively.
  • the base station transmitter 100b may transmit the precoded transmission data to the predetermined user equipments through the predetermined resource region under the control of the base station processor 400b.
  • the information specifying the lowest priority of the lowest codebook subset among the corresponding codebook subsets is not transmitted separately, but the information specifying the lowest ranking best companion W 3 is described. It is also possible to include in the precoding matrix information and transmit it. However, even if the lowest ranking best companion is not specified, by specifying the remaining three precoding matrices, the base station knows that W 3 of the four precoding matrices is the best companion having the lowest preference for user equipment 0. Can be.
  • the base station may receive precoding matrix information from user equipments in the area served by the base station, and select user equipments that may be scheduled together based on the precoding matrix information of the user equipments. For example, user equipment 0 feeds back to the base station precoding matrix information specifying the best precoding matrix and the best companion in the order of W 0 , W 3 , and W 1 , and user equipment 1 sends W 3 , W 1 , Feedback to the base station the precoding matrix information specifying the best precoding matrix and the best companion in order of W 2 , and user equipment 2 designates the best precoding matrix and the best companion in order of W 5 , W 7 , and W 4 .
  • precoding matrix information is fed back to the base station, and user equipment 3 feeds back the precoding matrix information specifying the best precoding matrix and the best companion in order of W 3 , W 1 , and W 0 to the base station. lets do it.
  • the processor 400b of the base station selects to schedule user devices 0 and 3 together to which a common precoding matrix is applied, and transmits data of user device 0 by using W 0 and transmits the user device 3. Data may be controlled by the precoder of the base station to precode using W 3 .
  • the base station processor may control the resource element mapper to allocate transmission data of the precoded user equipment 0 and the user equipment 3 to a predetermined resource region.
  • the base station transmitter under the control of the base station processor, transmits the transmission data to the user equipment 0 and the user equipment 3 in the predetermined resource region, that is, the frequency and time region of the predetermined resource region.
  • embodiments of the present invention are equally applicable to single user MIMO as well as multi-user MIMO. Applying the embodiments of the present invention regardless of whether a multi-user MIMO or a single user, the user equipment can send some form of precoding matrix information to the base station without considering which user equipments are scheduled together and how many users are scheduled together. Send it.
  • embodiments of the present invention are the same when a single or a plurality of user equipments in one cell served by one base station feed back precoding matrix information to the base station, as well as when applying MIMO transmission in a multi-cell environment. Can be applied. That is, embodiments of the present invention can be equally applied to multi-cell MIMO as well as single-cell MIMO. Hereinafter, a case in which embodiments of the present invention are applied to a multi-cell MIMO will be described with reference to FIG. 1.
  • a single cell MIMO user 160 within a single cell communicates with one serving base station in one cell (sector), and a multi cell MIMO user 150 located at a cell boundary is located in a multiple cell (sector).
  • Communication with multiple serving base stations can improve inter-cell interference and throughput of users at cell boundaries, which is referred to as a Coordinated Multi-Point (CoMP) system (hereinafter referred to as CoMP system).
  • CoMP systems are also referred to as multi-base station MIMO systems, network MIMO systems, and collaborative MIMO systems.
  • each base station forms a MIMO with single or multiple user equipments in its own coverage area and transmits a signal.
  • signals transmitted from base stations adjacent to each other are signals to be transmitted only within a radius of their own cells, and when the signals are transmitted to adjacent cells, interference between cells occurs.
  • the multi-cell MIMO different symbols of the MIMO transmitted to one user equipment are transmitted from adjacent base stations, and each symbol is transmitted from different base stations far apart from each other. This results in an excellent channel matrix.
  • applying the CoMP system can reduce inter-cell interference in a multi-cell environment. Using this CoMP system, the user equipment can be jointly supported with data from a multi-cell base station.
  • each base station can improve the performance of the system by simultaneously supporting communication with one or more user equipments (UE 0 , UE 1 , ..., UE K ) using the same radio frequency resource.
  • the base station may perform a space division multiple access (SDMA) method based on channel state information between the base station and the user equipment.
  • SDMA space division multiple access
  • CoMP scheme may be divided into cooperative MIMO-type joint processing through a data sharing and a coordinated scheduling scheme / beamforming scheme.
  • CoMP systems also include inter-cell cooperative processing and cooperative scheduling / beamforming techniques, as well as geographically separated transmission processes (eg, multiple antennas).
  • a serving base station and one or more cooperative base stations are connected to a scheduler through a backhaul 140.
  • each base station may include a scheduler for scheduling signals to be transmitted to user equipments in its own coverage area
  • a scheduler for scheduling signals of one or more base stations may be referred to as a master scheduler by distinguishing the scheduler from each base station. do.
  • the master scheduler is a channel between each user equipment (UE 0 , UE 1 , ..., UE K ) measured by each base station (BS 0 , BS 1 , ..., BS M ) through the backhaul 140 and the cooperative base station. It can operate by receiving channel information about the status.
  • the master scheduler schedules information for collaborative MIMO operations for the serving base station and one or more cooperating base stations. That is, the scheduler may directly indicate the cooperative MIMO operation to each base station.
  • Embodiments of the present invention are equally applicable to this CoMP system.
  • the user equipments receiving different symbols from the plurality of base stations may feed back information indicating the best precoding matrix and the best companion of the corresponding user equipment to each of the plurality of base stations according to an embodiment of the present invention.
  • the master scheduler receives the precoding matrix information of each user equipment received by each base station through the backhaul 140, selects user equipments to be scheduled together among several user equipments in the region of the plurality of base stations, and selects the selected user equipment. Can be assigned to the same time / frequency domain.
  • Each base station may allocate the user equipments selected in the self coverage area to the same time / frequency domain according to the control of the master scheduler.
  • the user equipment 0 (UE 0 ) feeds back the precoding matrix information specifying the best precoding matrix and the best companion in the order of W 0 , W 3 , and W 1 to eNB A, and the user equipment 1 (UE 1).
  • UE 0 Feeds back the precoding matrix information specifying the best precoding matrix and the best companion in order of W 2 , W 1 , and W 3 to eNB A
  • UE2 (UE 2 ) receives W 5 , W 7 , and W 4 in order.
  • eNB A which specifies the best precoding matrix and the best companion
  • UE 3 (UE 3 ) specifies the best precoding matrix and the best companion in order of W 3 , W 1 , and W 0 .
  • the precoding matrix information is fed back to the eNB A and the eNB B, and the user equipment 4 (UE 4 ) sends the precoding matrix information to the eNB B, which specifies the best precoding matrix and the best companion in the order of W 8 , W 11 , and W 12 .
  • the user equipment 5 (UE 5) is W 1, W 2, W 0 in order of best precoding matrix and in best Compassion Suppose a case where the feedback precoding matrix information given to the eNB B.
  • the master scheduler receives precoding matrix information of user devices 0 and 1, 2, 3, 4, and 5 from eNB A and eNB B, and based on the received precoding matrix information, the best scheduler and best companion are preferred.
  • the overlapping user equipment 0 and the user equipment 3 can be scheduled together and delivered to eNB A, and the preferred best precoding matrix and the best companion can be scheduled together and delivered to eNB B.
  • the master scheduler may select a precoding matrix for user equipments scheduled together based on the precoding matrix information received from each base station and inform the base station of the precoding matrix.
  • the best pre-coding matrix W 0 is the best Compassion in your device's 0 W 3, and W 1, so the best pre-coding of the user equipment 3 matrix W 3 is the best-Compassion-year W 1, W 0, the master scheduler user devices 0
  • the precoding matrix for may be W 0 and the precoding matrix for user equipment 3 may be designated as W 3 and transmitted to eNB A.
  • the best precoding matrix W 2 of user equipment 1 and the best companions are W 1 , W 3
  • the best precoding matrix W 1 of user equipment 5 and the best companion years are W 2 , W 0
  • the master scheduler is user.
  • the precoding matrix for device 1 may be designated as W 2 and the precoding matrix for user equipment 5 may be designated as W 1 and transmitted to eNB B.
  • the processor of the eNB A by precoding the data to be transmitted the data to be transmitted to the user device 0 to the user equipment 3 as W 0 to W 3 control the transmitter of the eNB A to send to the user's device 0 and 3, and the eNB B the processor may be pre-coded data to transmit the data to be transmitted to the user device 1 to user device 5 to W 2 to W 1 to control the transmitter of the B eNB to transmit the user equipment 1 and 5.
  • the master scheduler selects user equipments to be scheduled together by each base station based on the precoding matrix information transmitted from each base station, schedules the selected user equipments, and transmits the selected user equipments to the corresponding base station, and the base station selects a precoding matrix. It is also possible. For example, when the master scheduler schedules user equipments 0 and 3 together and transmits them to eNB A, and schedules user equipments 1 and 5 together and sends them to eNB B, the eNB A processor may schedule the user equipments 0 and 3 together. Based on the precoding matrix information from the device 3, the precoding matrix to be applied to the transmission data of the user device 0 and the transmission data of the user device 3 can be selected.
  • the processor of eNB B may select a precoding matrix to be applied to transmission data of user equipment 1 and transmission data of user equipment 5 based on precoding matrix information from user equipment 1 and user equipment 5 scheduled together. It may be.
  • the transmitter of the eNB A according to the control of the processor, precodes the transmission data of the user equipment 0 and the user equipment 3 into the selected corresponding precoding matrix, and transmits the precoded transmission data in the predetermined resource region. Send to Device 0 and User 3 together.
  • the transmitter of the eNB B precodes the transmission data of the user equipment 1 and the user equipment 5 to the selected corresponding precoding matrix and controls the precoded transmission data according to the control of the processor. It transmits to the user device 1 and the user device 5 together in the resource area.
  • the master scheduler designates only the user equipments that can be scheduled together and transmits the data to each base station, and the base station allocates data for the designated user equipments to the same time / frequency domain and to the data for the designated user equipments. It is also possible to select a precoding matrix to apply.
  • the processor of eNB A Allocating data for user equipments 0 and 3 in the same time / frequency domain and based on precoding matrix information of user equipments 0 and 3, precoding matrix W 0 for user equipment 0 and precoding matrix W for user equipment 3 3 is selected, the processor of eNB B allocates data for user equipments 1 and 5 to the same time / frequency domain, and based on the precoding matrix information of user equipments 1 and 5, precoding matrix W 2 and The precoding matrix W 1 for the user device 3 may be selected.
  • the transmitter of the eNB A precodes data to be transmitted to user device 0 with W 0 and precodes data to be transmitted to user device 3 with W 3 under the control of the corresponding processor. May transmit to the user devices 0 and 3, respectively.
  • the transmitter of the eNB B under the control of the processor, precodes data to be transmitted to the user equipment 1 to W 2 and precodes the data to be transmitted to the user equipment 5 to W 1 so as to transmit a time of a predetermined resource region through an antenna. And the user equipments 1 and 5, respectively, at a frequency.
  • each base station other than the master scheduler it is also possible to receive feedback information received by another base station through the backhaul 140 and select a user equipment and a precoding matrix to be scheduled together.
  • the processor of the eNB A may schedule the user devices 0 and 3 together based on the precoding matrix information transmitted from the user devices 0 and 1, 2, 3, and W 0 to transmit data to the user devices 0 and 3. And control the precoder of eNB A to precode each to W 3 , and control the transmitter and antenna of eNB A to transmit the precoded data to user devices 0 and 3 through a predetermined resource region.
  • Application of the embodiments of the present invention to a CoMP system can reduce not only inter-cell interference occurring in an interview area between different cells, but also channel interference by a plurality of users scheduled together. There is this.
  • Embodiments of the present invention may be used in a base station or terminal, or other equipment in a wireless communication system.

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Abstract

L'invention concerne un procédé de transmission d'informations relatives à une matrice de précodage et un dispositif utilisateur, et notamment un procédé de transmission d'informations relatives à une matrice de précodage par un dispositif utilisateur particulier parmi plusieurs dispositifs utilisateurs recevant un signal transmis par une station de base. Le procédé comprend les étapes consistant: à déterminer, à partir d'une liste de codage prédéfinie, une première matrice de précodage qui consiste en une matrice de précodage destinée au dispositif utilisateur particulier durant la réception du signal, et à déterminer une ou plusieurs deuxièmes matrices de précodage pour les autres dispositifs utilisateurs devant être multiplexés dans une région ressource prédéfinie avec le dispositif utilisateur particulier, la ou les deuxièmes matrices de précodage étant déterminées dans un sous-ensemble de listes de codage de la liste de codage prédéfinie liée à la première matrice de précodage; et une étape de transmission d'informations relatives à une matrice de précodage consistant à transmettre, à la station de base, les informations relatives à la première matrice de précodage indiquant la première matrice de précodage et les informations relatives à la deuxième matrice de précodage indiquant la ou les deuxièmes matrices de précodage.
PCT/KR2010/008397 2009-11-30 2010-11-25 Procédé de transmission d'informations relatives à une matrice de précodage et dispositif utilisateur, et procédé de transmission de données à plusieurs dispositifs utilisateurs et à une station de base Ceased WO2011065763A2 (fr)

Priority Applications (2)

Application Number Priority Date Filing Date Title
US13/511,596 US8989115B2 (en) 2009-11-30 2010-11-25 Method for transmitting precoding matrix information and user device, and method for transmitting data to plurality of user devices and base station
CN201080054267.9A CN102640429B (zh) 2009-11-30 2010-11-25 发射预编码矩阵信息的方法和装置

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US26484409P 2009-11-30 2009-11-30
US61/264,844 2009-11-30
KR10-2010-0055385 2010-06-11
KR1020100055385A KR101717524B1 (ko) 2009-11-30 2010-06-11 프리코딩 행렬 정보를 전송하는 방법 및 사용자기기와, 복수의 사용자기기에 데이터를 전송하는 방법 및 기지국

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CN104380637A (zh) * 2012-05-28 2015-02-25 日本电气株式会社 生成在优化dl mu-mimo通信系统中的e节点b与ue之间的传输能力中使用的预编码器
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CN104662942A (zh) * 2012-09-18 2015-05-27 日本电气株式会社 改善dl mu-mimo通信系统的传输能力的方法
CN107925454A (zh) * 2015-08-24 2018-04-17 华为技术有限公司 一种预编码信息发送、反馈方法及装置
CN114513289A (zh) * 2020-11-16 2022-05-17 上海朗帛通信技术有限公司 一种被用于无线通信的节点中的方法和装置

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Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2013117068A1 (fr) * 2012-02-10 2013-08-15 中兴通讯股份有限公司 Procédé de sélection de précodage dans une transmission multipoint coordonnée, station de base, et terminal
US20150139004A1 (en) * 2012-05-22 2015-05-21 Telefonaktiebolaget Lm Ericsson (Publ) Method and arrangement for interference mitigation
US9819470B2 (en) * 2012-05-22 2017-11-14 Telefonaktiebolaget Lm Ericsson (Publ) Method and arrangement for interference mitigation
CN104380637A (zh) * 2012-05-28 2015-02-25 日本电气株式会社 生成在优化dl mu-mimo通信系统中的e节点b与ue之间的传输能力中使用的预编码器
CN104380637B (zh) * 2012-05-28 2018-03-13 日本电气株式会社 生成在优化dl mu‑mimo通信系统中的e节点b与ue之间的传输能力中使用的预编码器
WO2013185525A1 (fr) * 2012-06-12 2013-12-19 富士通株式会社 Dispositif de transmission, et procédé et système de communication en rapport avec une pluralité de points de transmission coordonnée
CN104662942A (zh) * 2012-09-18 2015-05-27 日本电气株式会社 改善dl mu-mimo通信系统的传输能力的方法
CN104662942B (zh) * 2012-09-18 2018-11-16 日本电气株式会社 改善dl mu-mimo通信系统的传输能力的方法
CN107925454A (zh) * 2015-08-24 2018-04-17 华为技术有限公司 一种预编码信息发送、反馈方法及装置
CN114513289A (zh) * 2020-11-16 2022-05-17 上海朗帛通信技术有限公司 一种被用于无线通信的节点中的方法和装置

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