WO2010021471A2 - Communication system including base stations and terminal for multi-cell cooperative communication - Google Patents
Communication system including base stations and terminal for multi-cell cooperative communication Download PDFInfo
- Publication number
- WO2010021471A2 WO2010021471A2 PCT/KR2009/004548 KR2009004548W WO2010021471A2 WO 2010021471 A2 WO2010021471 A2 WO 2010021471A2 KR 2009004548 W KR2009004548 W KR 2009004548W WO 2010021471 A2 WO2010021471 A2 WO 2010021471A2
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- base station
- phase shift
- terminal
- matrix
- shift matrix
- Prior art date
Links
- 238000004891 communication Methods 0.000 title claims abstract description 47
- 239000011159 matrix material Substances 0.000 claims abstract description 262
- 230000010363 phase shift Effects 0.000 claims abstract description 141
- 238000000034 method Methods 0.000 claims description 42
- 239000013598 vector Substances 0.000 description 34
- 230000005540 biological transmission Effects 0.000 description 17
- 238000010586 diagram Methods 0.000 description 16
- 238000012546 transfer Methods 0.000 description 4
- 238000005516 engineering process Methods 0.000 description 3
- 238000011160 research Methods 0.000 description 2
- 230000010267 cellular communication Effects 0.000 description 1
- 230000001413 cellular effect Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
Images
Classifications
-
- 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
- H04B7/022—Site diversity; Macro-diversity
- H04B7/024—Co-operative use of antennas of several sites, e.g. in co-ordinated multipoint or co-operative multiple-input multiple-output [MIMO] systems
-
- 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
-
- 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
-
- 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
- H04B7/0456—Selection of precoding matrices or codebooks, e.g. using matrices antenna weighting
-
- 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
- H04B7/0621—Feedback content
- H04B7/0634—Antenna weights or vector/matrix coefficients
-
- 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
-
- 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
- H04B7/0667—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 delayed versions of same signal
- H04B7/0671—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 delayed versions of same signal using different delays between antennas
Definitions
- Embodiments of the present invention relate to a multiple input multiple output (MIMO) communication system, and more particularly, to technologies required for at least two base stations to serve at least one terminal in a multi-cell MIMO communication system.
- MIMO multiple input multiple output
- a single-cell MIMO communication system includes a single base station.
- the single-cell MIMO communication system may be classified into a single-cell multi-user MIMO communication system including a plurality of users and a single base station, and a single-cell single-user MIMO communication system including a single user and a single base station.
- At least one base station and terminals may use a codebook.
- a particular space may be quantized into a plurality of vectors or matrices.
- the plurality of vectors or matrices may be stored as the codebook in the base station and the terminals.
- Each of the terminals may select any one vector or matrix from vectors or matrices included in the codebook, based on a channel between the base station and each of the terminals.
- the base station may also verify the selected vector matrix using the codebook.
- the selected vector or matrix may be used for the base station to generate a precoding vector or a precoding matrix.
- a scheme of performing precoding as described above is referred to as a codebook-based precoding scheme.
- a research regarding a multi-cell MIMO communication system including a plurality of base stations is being conducted.
- at least two base stations may serve at least one terminal through a mutual cooperation. Since the at least two base stations cooperate with each other, it is possible to enhance a transmission rate to a terminal, particularly, a terminal that is located in a cell edge.
- the codebook-based precoding scheme may be used even in the multi-cell MIMO communication system.
- a difference between the multi-cell MIMO communication system and the single-cell MIMO communication system lies in that the multi-cell MIMO communication system includes at least two base stations and the single-cell MIMO communication system includes a single base station. Accordingly, when the codebook-based precoding scheme used in the single-cell MIMO communication system is applied to the multi-cell MIMO communication as is, it may cause a problem.
- An aspect of the present invention provides a base station and a terminal that may shift a phase of at least one element among elements included in a precoding matrix, using a phase shift matrix, to thereby perform precoding optimized for a multi-cell cooperative communication.
- Another aspect of the present invention also provides a base station and a terminal that may adaptively use a phase shift matrix to perform a multi-cell cooperative communication achieving an enhanced capacity.
- Another aspect of the present invention also provides a base station and a terminal that may more effectively determine a phase shift matrix using a codebook including a plurality of candidate matrices.
- Another aspect of the present invention also provides a terminal that may calculate a preferred phase shift matrix with a small calculation amount.
- Another aspect of the present invention also provides a base station that may adaptively adjust a power weight.
- a method of operating a serving base station for a multi-cell cooperative communication in cooperation with at least one neighboring base station including: generating a precoding matrix based on a plurality of codeword matrices; providing a phase shift matrix to shift a phase of at least one element among elements included in the precoding matrix; and precoding at least one data symbol using the phase shift matrix and the precoding matrix.
- the method may further include adjusting a transmit power of the precoded at least one data symbol.
- the adjusting may include adaptively adjusting the transmit power of the precoded at least one data symbol based on at least one of a channel between the at least one neighboring base station and a terminal, a channel between the serving base station and the terminal, and an achievable capacity of the terminal.
- the providing may include adaptively providing the phase shift matrix based on at least one of a channel between the at least one neighboring base station and a terminal, a channel between the serving base station and the terminal, and an achievable capacity of the terminal.
- the providing may include generating the phase shift matrix based on an effective channel between the at least one neighboring base station and a terminal or an effective channel between the at least one neighboring base station and the terminal with respect to each of the at least one data symbol.
- the providing may include providing the phase shift matrix using a plurality of candidate matrices pre-stored in a memory.
- the method may further include receiving, from a terminal, information associated with a preferred phase shift matrix.
- the providing may include providing the phase shift matrix based on information associated with the preferred phase shift matrix.
- information associated with the preferred phase shift matrix may be generated by the terminal based on an achievable capacity of the terminal, or may be generated by the terminal based on an effective channel between the serving base station and the terminal or an effective channel between the at least one neighboring base station and the terminal with respect to each of the at least one data symbol.
- the providing may include providing the phase shift matrix in a form of a diagonal matrix.
- the providing may include providing the phase shift matrix in order to shift a phase of each of at least one precoding vector included in the precoding matrix, based on a column vector unit.
- the method may further include transferring, to the at least one neighboring base station, information associated with the phase shift matrix, information associated with the precoding matrix, or information associated with the transmit power.
- a method of operating a terminal for a multi-cell cooperative communication through a mutual cooperation between at least one neighboring base station and a servicing base station including: driving a memory storing a plurality of candidate matrices; generating information associated with a preferred phase shift matrix among the plurality of candidate matrices, so that the at least one neighboring base station or the serving base station uses a phase shift matrix to shift a phase of at least on element among elements included in a precoding matrix; and feeding back, to the at least one neighboring base station or the serving base station, information associated with the preferred phase shift matrix.
- the generating may include generating information associated with the preferred phase shift matrix based on an achievable capacity.
- the generating may include generating information associated with the preferred phase shift matrix based on an effective channel between the at least one neighboring base station and a terminal or an effective channel between the serving base station and the terminal with respect to each of at least one data symbol that the at least one neighboring base station or the serving base station desires to precode.
- the generating may include determining the preferred phase shift matrix after determining at least one of a number of preferred data symbols and the preferred precoding matrix.
- the method may further include feeding back information associated with a preferred power weight so that the at least one neighboring base station or the serving base station adjust a transmit power of at least one data symbol.
- a serving base station for a multi-cell cooperative communication in cooperation with at least one neighboring base station, the serving base station including: a memory to store a plurality of codeword matrices and a plurality of candidate matrices; a precoding matrix generator to generate a precoding matrix based on the plurality of codeword matrices stored in the memory; a phase shift matrix providing unit to provide a phase shift matrix based on the plurality of candidate matrices in order to shift a phase of at least one element among elements included in the precoding matrix; and a precoder to precode at least one data symbol using the phase shift matrix and the precoding matrix.
- the serving base station may further include: an information receiver to receive, from a terminal, information associated with a preferred phase shift matrix; and a power weight adjustment unit to adjust a power weight based on information associated with a preferred power weight fed back from the terminal, in order to adjust a transmit power of the precoded at least one data symbol.
- the phase shift matrix providing unit may provide the phase shift matrix based on information associated with the preferred phase shift matrix.
- a terminal for a multi-cell cooperative communication performed through a mutual cooperation between at least one neighboring base station and a serving base station including: a memory to store a plurality of codeword matrices and a plurality of candidate matrices that are used to feed back information associated with a preferred precoding matrix; an information generator to generate information associated with a preferred phase shift matrix among the plurality of candidate matrices, so that the at least one neighboring base station or the serving base station uses a phase shift matrix to shift a phase of at least one element among elements included in the precoding matrix; and an information feedback unit to feed back, to the at least one neighboring base station or the serving base station, information associated with the preferred phase shift matrix.
- the information generator may generate information associated with the preferred phase shift matrix based on an achievable capacity, or may generate information associated with the preferred phase shift matrix based on an effective channel between the serving base station and a terminal or an effective channel between the at least one neighboring base station and the terminal with respect to each of at least one data symbol that the at least one neighboring base station or the serving base station desires to precode.
- the information generator may include a decision unit to determine the preferred phase shift matrix after determining at least one of a number of preferred data symbols and the preferred precoding matrix.
- a method of operating a neighboring base station for a multi-cell cooperative communication in cooperation with a serving base station including: receiving, from the serving base station, information regarding a phase shift matrix and a precoding matrix; and precoding at least one data symbol that the serving base station desires to transmit using the phase shift matrix and the precoding matrix.
- the method may further include extracting the phase shift matrix from a plurality of candidate matrices pre-stored in a memory, based on information associated with the phase shift matrix.
- phase shift matrix may be in a form of a diagonal matrix.
- the method may further include: receiving information associated with a transmit power from the serving base station; and adjusting a transmit power of the precoded at least one data symbol based on information associated with the transmit power.
- FIG. 1 is a diagram illustrating a base station and terminals included in a single-cell multi-user multiple input multiple output (MIMO) communication system according to an embodiment of the present invention
- FIG. 2 is a diagram for describing a precoding matrix, and a channel and an effective channel between a base station and a terminal according to an embodiment of the present invention
- FIG. 3 is a diagram illustrating an example of a multi-cell MIMO communication system according to an embodiment of the present invention
- FIG. 4 is a diagram illustrating two base stations and a terminal in a multi-cell MIMO communication system according to an embodiment of the present invention
- FIG. 5 is a conceptual diagram illustrating an effective channel between a base station (BS1) and a terminal, and an effective channel between a base station (BS2) and the terminal with respect to a data symbol x 1 according to an embodiment of the present invention
- FIG. 6 illustrates examples of shifting phases of elements included in a precoding matrix according to an embodiment of the present invention
- FIG. 7 is a flowchart illustrating a method of operating a serving base station according to an embodiment of the present invention.
- FIG. 8 is a flowchart illustrating a method of operating a terminal according to an embodiment of the present invention.
- FIG. 9 is a block diagram illustrating a configuration of a serving base station and a terminal according to an embodiment of the present invention.
- FIG. 10 is a flowchart illustrating a method of operating a neighboring base station according to an embodiment of the present invention.
- the term "base station” used throughout the present specification may include a general base station of a cellular communication system and various types of devices.
- the base station may include a femto base station, a small base station such as a pico base station, a relay, and the like. Therefore, the base station may include devices that are used to serve various types of receivers such as terminals.
- the term "terminal” used throughout the present specification may include a mobile device such as a cellular phone, a notebook, a smart phone, and the like, and may also include various types of devices receiving data signals from the base station or the relay.
- FIG. 1 is a diagram illustrating a base station and terminals included in a single-cell multi-user multiple input multiple output (MIMO) communication system according to an embodiment of the present invention.
- MIMO multiple input multiple output
- the single-cell multi-user MIMO communication system may include a single base station 110 and K terminals (terminal 1, ..., terminal K) 121 and 122.
- the base station 110 may include transmit antennas.
- Each of the terminals (terminal 1, ..., terminal K) 121 and 122 may include at least one receive antenna.
- i denotes an index of the base station 110.
- Channels may be formed between the base station 110 and the terminals (terminal 1, ..., terminal K) 121 and 122.
- Each of the base station and the terminals (terminal 1, ..., terminal K) 121 and 122 may transmit and receive various signals via the channels.
- the base station 110 may transmit at least one data symbol to the terminals (terminal 1, ..., terminal K) 121 and 122.
- the base station 110 may perform beamforming for the at least one data symbol according to a spatial division multiplexing access (SDMA) scheme.
- SDMA spatial division multiplexing access
- the base station 110 may determine a precoding matrix using a codebook, and precode at least one data symbol using the determined precoding matrix.
- a codebook S (i) may be expressed by the following Equation 1:
- L denotes a number of layers and corresponds to a number of data symbols to be simultaneously transmitted.
- a dimension of W n,L is .
- the base station 110 may transmit well-known signals such as pilot signals to the terminals (terminal 1, ..., terminal K) 121 and 122 via a downlink channel.
- each of the terminals (terminal 1, ..., terminal K) 121 and 122 may estimate a channel between the base station 110 and each of the terminals (terminal 1, ..., terminal K) 121 and 122 using the pilot signals.
- Each of the terminals (terminal 1, ..., terminal K) 121 and 122 may select, as a preferred precoding matrix, any one matrix from the codebook matrices included in the codebook S (i) according to various types of criteria, based on the estimated channel. For example, each of the terminals (terminal 1, ..., terminal K) 121 and 122 may select the preferred precoding matrix by considering various types of factors, for example, an achievable capacity, a signal-to-interference plus noise ratio (SINR), and the like.
- SINR signal-to-interference plus noise ratio
- Each of the terminals (terminal 1, ..., terminal K) 121 and 122 may feed back the preferred precoding matrix to the base station 110.
- information associated with the preferred precoding matrix is also referred to as a preferred matrix indicator (PMI) or a precoding matrix indicator (PMI).
- each of the terminals (terminal 1, ..., terminal K) 121 and 122 may feed back, to the base station 110, information associated with a number of preferred layers.
- Each of the terminals (terminal 1, ..., terminal K) 121 and 122 may feed back, to the base station 110, information associated with the achievable capacity, information associated with the SINR, and the like.
- the base station 110 may determine the precoding matrix and the number of layers to be applied, based on information associated with the preferred precoding matrix and information associated with the number of preferred layers that are fed back from each of the terminals (terminal 1, ..., terminal K) 121 and 122.
- the base station 110 may determine the number of layers L and generate the precoding matrix based on any one of codeword matrices with respect to the number of layers L, included in the codebook S (i) .
- any one codeword matrix may be selected as the precoding matrix from the codeword matrices included in the codebook S (i) with respect to the number of layers L.
- each of L vectors included in is a column vector and is referred to as a "precoding vector”.
- Precoding vector may be expressed by the following Equation 2:
- x When L data symbols that the base station 110 desires to transmit are , x may be referred to as a transmission symbol vector.
- transmission signals output via the transmit antennas of the base station 110 may be expressed by the following Equation 3:
- FIG. 2 is a diagram for describing a precoding matrix, and a channel and an effective channel between a base station and a terminal 1 according to an embodiment of the present invention.
- the channel between the base station and the terminal 1 may be expressed as "H".
- the base station may precode L data symbols using .
- a received signal vector r received by the terminal 1 via n R receive antennas may be expressed by the following Equation 4:
- z denotes a sum of interference and noise.
- Equation 4 It can be known from the above Equation 4 that x is transmitted from the base station to the terminal 1 via an effective channel . Therefore, one of schemes to enhance a transmission rate to the terminal 1 may select or determine to maximize a magnitude of the effective channel .
- FIG. 3 is a diagram illustrating an example of a multi-cell MIMO communication system according to an embodiment of the present invention.
- a plurality of base stations may serve a single terminal through a mutual cooperation.
- any one base station among the plurality of base stations (BS1, BS2, BSi) may be referred to as a "serving base station”, and the remaining base stations may be referred to as “neighboring base stations”.
- the base stations may transmit the same transmission symbol vector x via channels H (1) , H (2) , and H (i) , respectively.
- Equation 5 the received signal vector r received by the terminal via n R receive antennas may be expressed by the following Equation 5:
- a precoding matrix that is used by the base station (BSi) denotes a precoding matrix that is used by the base station (BSi) as an n(i) th codeword matrix among codeword matrices included in a codebook S (i) with respect to a number of layers L.
- the codebook S (i) denotes the codebook of the base station (BSi).
- H (i) denotes a matrix that expresses a channel between the base station (BSi) and the terminal
- z denotes a sum of interference and noise.
- FIG. 4 is a diagram illustrating two base stations (BS1, BS2) and a terminal in a multi-cell MIMO communication system according to an embodiment of the present invention.
- the two base stations may transmit a transmission symbol vector x through a mutual cooperation.
- the number of layers is two and the transmission symbol vector x includes two data symbols x 1 and x 2 .
- the received signal vector r may be expressed by the following Equation 6:
- Equation 7 the received signal vector r of the above Equation 6 may be expressed by the following Equation 7:
- the data symbol x 1 may be received through a sum of and
- the data symbol x 2 may be received through a sum of and .
- a norm of the sum of and may need to increase To enhance a transmission rate to the terminal with respect to the data symbol x 1 , a norm of the sum of and may need to increase. To enhance a transmission rate to the terminal with respect to the data symbol x 2 , a norm of the sum of and may need to increase.
- the capacity of the terminal may vary according to reception schemes of the terminal.
- the terminal may use a minimum mean square error (MMSE) successive interference cancellation (SIC) reception scheme.
- MMSE minimum mean square error
- SIC successive interference cancellation
- the received signal vector r may be expressed by the following Equation 8:
- the capacity of the terminal may be expressed by the following Equation 9:
- Equation 10 Equation 10
- the terminal may feed back, to the base station, information association with the preferred precoding matrix, that is, information associated with , and information associated with an achievable capacity .
- One of schemes to reduce calculation amounts may sequentially obtain and .
- the terminal may obtain , and may subsequently obtain that may maximize with respect to .
- the aforementioned process where the terminal obtains and sequentially obtains may be expressed by the following Equation 12:
- the terminal may calculate with respect only to 2N cases, and thereby may obtain and . Accordingly, it is possible to significantly reduce calculation amounts.
- FIG. 5 is a conceptual diagram illustrating an effective channel between a base station (BS1) and a terminal, and an effective channel between a base station (BS2) and the terminal with respect to a data symbol x 1 according to an embodiment of the present invention.
- the terminal may receive data symbols from the at least two base stations via at least two effective channels, respectively.
- a single data symbol may be transmitted from the at least two base stations to the terminal via the at least two effective channels.
- a chordal distance or an angle between and is relatively great Therefore, it is predicted that the norm of the sum of and is relatively small.
- the transmission rate to the terminal with respect to the data symbol x 1 is relatively small.
- a chordal distance or an angle between and is relatively small Therefore, it is predicted that the norm of the sum of and is relatively great.
- the transmission rate to the terminal with respect to the data symbol x 1 is relatively great.
- FIG. 6 illustrates examples 610 and 620 of shifting phases of elements included in a precoding matrix according to an embodiment of the present invention.
- effective channels may be appropriately arranged with respect to each data symbol by shifting a phase of at least one element among the elements included in the precoding matrix. Accordingly, a capacity of a terminal may be maximized or increase by appropriately arranging the effective channels.
- a first precoding vector of the precoding matrix is .
- elements of are ⁇ and ⁇ .
- the phase of at least one element among the elements included in the precoding matrix may be appropriately shifted using a phase shift matrix .
- the phase shift matrix may have various types of forms, and may be in a simple form of a diagonal matrix.
- the phase shift matrix may have an L x L dimension.
- the phase shift matrix in the form of the diagonal matrix may collectively shift phases of all the elements, included in the precoding vector, to be the same based on the column vector unit.
- phase shift matrix in the form of the diagonal matrix may be expressed by the following Equation 13:
- Equation 14 a phase of may be different, but a magnitude thereof may be the same. Specifically, may be expressed by the following Equation 14:
- any one base station for example, a base station of a cell including a terminal may use, as the phase shift matrix , a unitary matrix I LxL having an L x L dimension.
- the base stations participating in the multi-cell cooperative communication may include a serving base station and at least one neighboring base station.
- the terminal may feed back information associated with a preferred phase shift matrix to the serving base station.
- the serving base station may determine and use a corresponding phase shift matrix based on information associated with the preferred phase shift matrix.
- each of the at least one neighboring base station may receive, from the serving base station, information associated with the determined phase shift matrix to use the phase shift matrix.
- the terminal, the serving base station, and the at least one neighboring base station may store and use the same codebook with respect to the phase shift matrix.
- the codebook with respect to the phase shift matrix may be designed into various types.
- the codebook may include candidate matrices with respect to the phase shift matrix , and may also include individual candidate matrices with respect to each of L elements.
- a transmission signal of a base station may be expressed by the following Equation 15:
- Equation 16 a received signal vector r pro of the terminal.
- M 2 and a number of layers is 2.
- Equation 17 the received signal vector r pro of the above Equation 16 may be expressed by the following Equation 17:
- Equation 17 may be defined as given by the following Equation 18:
- Equation 17 may be expressed by the following Equation 19:
- phase shift matrix it is possible to maximize a transmission rate of the data symbol x 1 and the data symbol x 2 by appropriately determining the phase shift matrix . For example, when is appropriately determined, may become greater than . Also, when is appropriately determined, may also become greater than . Accordingly, it is possible to appropriately determine the phase shift matrix so that and may be maximized.
- the phase shift matrix may be determined to maximize a capacity of the terminal. Also, the phase shift matrix may be determined to decrease interference occurring between data symbols.
- a power weight P (i) may be used to adaptively adjust the transmit power.
- P (i) denotes a real number.
- the terminal may feed back, to the serving base station, information associated with a preferred power weight.
- the serving base station may appropriately determine the transmit power based on information associated with the preferred power weight, and may apply the determined transmit power.
- the serving base station may transfer information associated with the determined transmit power to at least one neighboring base station, so that the at least one neighboring base station may apply the adaptively adjusted transmit power.
- each of the serving base station and the at least one neighboring base station may adaptively apply the power weight P (i) .
- a particular base station not participating in the multi-cell cooperative communication may determine the power weight P (i) of zero.
- the terminal may determine the preferred precoding matrix and the preferred phase shift matrix by considering effective channels with respect to each data symbol.
- the terminal may calculate a capacity, an SINR, and the like, from the received signal vector .
- the terminal may calculate the preferred precoding matrix and the preferred phase shift matrix based on the capacity, the SINR, and the like.
- the preferred precoding matrix and the preferred phase shift matrix it is possible to simultaneously calculate the preferred precoding matrix and the preferred phase shift matrix so that the capacity, the SINR, and the like may be maximized.
- to simultaneously calculate the preferred precoding matrix and the preferred phase shift matrix may require large calculation amounts and thus may not be well applicable to the terminal.
- calculation amounts by sequentially calculating the preferred precoding matrix and the preferred phase shift matrix .
- the calculation amounts may be reduced by initially finding the number of preferred layers L and the preferred precoding matrix , and subsequently finding the preferred phase shift matrix .
- a received signal vector includes only z and a signal transmitted from the base station i 0 , as given by the following Equation 20:
- the terminal may find the preferred precoding matrix and the number of preferred layers L, maximizing a capacity, according to various types of reception schemes such as an MMSE-SIC reception scheme and the like.
- reception schemes such as an MMSE-SIC reception scheme and the like.
- Equation 22 Equation 22
- Equation 23 may require a calculation amount to be in proportion to MN.
- it has been described above with reference to the above Equation 11 that to simultaneously find all the preferred precoding matrices with respect to i 0 1, 2, 3, . . ., M may require a calculation amount in proportion to N M
- to individually find a preferred precoding matrix with respect to i 0 1, 2, 3, . . ., M after assuming that the received signal vector includes only z and a signal transmitted from the base station i 0 may require a calculation amount in proportion to MN.
- the preferred phase shift matrix may be obtained.
- the preferred phase shift matrix may be obtained to maximize the capacity of the terminal.
- Equation 18 and Equation 19 may be obtained using the above Equation 18 and Equation 19 so that each of and may be maximized.
- the capacity of the terminal may be calculated with respect to the obtained and .
- a preferred phase shift matrix may be determined by selecting and so that the calculated capacity may be maximized.
- a terminal may feed back, to a serving base station, information regarding a number of preferred layers, a preferred precoding matrix, a preferred phase shift matrix, and an achievable capacity.
- the terminal may also feed back information associated with a preferred power weight.
- the serving base station may determine a precoding matrix, a phase shift matrix, and a power weight, that is, a transmit power to be substantially applied.
- the serving base station may transfer, to at least one neighboring base station, information regarding the determined precoding matrix, the phase shift matrix, and the power weight, that is, the transmit power.
- FIG. 7 is a flowchart illustrating a method of operating a serving base station according to an embodiment of the present invention.
- the serving base station among base stations participating in a multi-cell cooperative communication may receive, from a terminal, information regarding a preferred precoding matrix, a number of preferred layers, a preferred phase shift matrix, and a preferred power weight.
- the serving base station may generate a precoding matrix, based on information regarding the preferred precoding matrix and the number of preferred layers.
- a plurality of codeword matrices used to determine the precoding matrix may be stored in a memory of the serving base station.
- the serving base station may determine and provide a phase shift matrix based on information associated with the preferred phase shift matrix.
- the serving base station may determine a power weight based on information associated with the preferred power weight.
- a plurality of candidate matrices may be stored in the memory of the serving base station to determine the phase shift matrix.
- the serving base station may precode at least one data symbol based on the precoding matrix, the number of layers, the phase shift matrix, and the power weight.
- a phase of at least one element among elements included in the precoding matrix may be shifted using the phase shift matrix.
- the serving base station may transmit the precoded at least one data symbol via a plurality of transmit antennas.
- at least one neighboring base station may cooperate with the serving base station to thereby transmit the same at least one data symbol.
- FIG. 8 is a flowchart illustrating a method of operating a terminal according to an embodiment of the present invention.
- the terminal may estimate a channel between the terminal and each of a serving base station and at least one neighboring base station.
- the serving base station and the at least one neighboring base station may transmit a reference signal such as a pilot signal to the terminal.
- the terminal may estimate the channel based on the reference signal.
- the terminal may determine a number of preferred layers, a preferred precoding matrix, a preferred phase shift matrix, and a preferred power weight based on the estimated channel. Specifically, the terminal may predict an effective channel based on the estimated channel whereby an SINR and an achievable capacity of the terminal may be calculated. The terminal may determine the number of preferred layers, the preferred precoding matrix, the preferred phase shift matrix, and the preferred power weight, based on the predicted effective channel, the calculated achievable capacity, and the SINR.
- the terminal may feed back, to the serving base station, information regarding the number of preferred layers, the preferred precoding matrix, the preferred phase shift matrix, and the preferred power weight.
- the serving base station may determine a number of layers, a precoding matrix, a phase shift matrix, and a power weight, that is, a transmit power to be substantially applied, based on information regarding the number of preferred layers, the preferred precoding matrix, the preferred phase shift matrix, and the preferred power weight.
- the serving base station may transfer, to the at least one neighboring base station, information regarding the determined number of layers, the precoding matrix, the phase shift matrix, and the power weight, that is, the transmit power.
- the exemplary embodiments of the present invention include computer-readable media including program instructions to implement various operations embodied by a computer.
- the media may also include, alone or in combination with the program instructions, data files, data structures, tables, and the like.
- the media and program instructions may be those specially designed and constructed for the purposes of the present invention, or they may be of the kind well known and available to those having skill in the computer software arts.
- Examples of computer-readable media include magnetic media such as hard disks, floppy disks, and magnetic tape; optical media such as CD ROM disks; magneto-optical media such as floptical disks; and hardware devices that are specially configured to store and perform program instructions, such as read-only memory devices (ROM) and random access memory (RAM).
- Examples of program instructions include both machine code, such as produced by a compiler, and files containing higher level code that may be executed by the computer using an interpreter.
- the described hardware devices may be configured to act as one or more software modules in order to perform the operations of the above-described embodiments of the present invention, or vice versa.
- FIG. 9 is a block diagram illustrating a configuration of a serving base station 910 and a terminal 920 according to an embodiment of the present invention.
- the serving base station 910 may include an information receiver 911, a memory 912, a precoding matrix generator 913, a phase shift matrix providing unit 914, a power weight adjustment unit 915, and a precoder 916.
- the information receiver 911 may receive, from the terminal 920, information regarding a number of preferred layers, a preferred precoding matrix, a preferred power weight, and a preferred phase shift matrix.
- the precoding matrix generator 913 may select a precoding matrix based on information regarding the number of preferred layers and the preferred precoding matrix, and a plurality of codeword matrices that are pre-stored in the memory 912.
- the phase shift matrix providing unit 914 may determine and provide a phase shift matrix based on information associated with the preferred phase shift matrix.
- a plurality of candidate matrices used to determine the phase shift matrix may be stored in the memory 912.
- the power weight adjustment unit 915 may determine a power weight, that is, a transmit power based on information associated with the preferred power weight.
- the precoder 916 may precode at least one data symbol using the precoding matrix, the phase shift matrix, and the power weight.
- the terminal 920 may include a channel estimator 921, a memory 922, an information generator 923, and a feedback unit 924.
- the channel estimator 921 may estimate a channel between each of base stations and the terminal 920.
- the information generator 923 may generate information associated with the preferred precoding matrix, based on the estimated channel and a plurality of codeword matrices pre-stored in the memory 922.
- the information generator 923 may additionally generate information regarding the number of preferred layers, the preferred phase shift matrix, and the preferred power weight.
- the preferred precoding matrix, the number of preferred layers, the preferred phase shift matrix, and the preferred power weight may be sequentially determined, or may also be simultaneously determined.
- the feedback unit 924 may feed back, to the serving base station 910, information regarding the preferred precoding matrix, the number of preferred layers, the preferred phase shift matrix, and the preferred power weight.
- the serving base station 910 may determine a number of layers, a precoding matrix, a phase shift matrix, and a power weight, that is, a transmit power to be substantially applied, based on information regarding the number of preferred layers, the preferred precoding matrix, the preferred phase shift matrix, and the preferred power weight.
- the serving base station 910 may transfer, to at least on neighboring base station, information regarding the determined number of layers, the precoding matrix, the phase shift matrix, and the power weight, that is, the transmit power.
- FIG. 10 is a flowchart illustrating a method of operating a neighboring base station according to an embodiment of the present invention.
- the neighboring base station may determine a phase shift matrix based on information associated with a preferred phase shift matrix received from a serving base station.
- the neighboring base station may store a plurality of candidate matrices in a memory, and may verify, from the plurality of candidate matrices, a candidate matrix corresponding to information associated with the preferred phase shift matrix.
- the neighboring base station may determine a phase shift matrix based on the verified candidate matrix.
- the neighboring base station may determine a precoding matrix based on information associated with a preferred precoding matrix received from the serving base station.
- the neighboring base station may determine a precoding matrix using a plurality of codeword matrices included in a codebook.
- the neighboring base station may determine a transmit power based on information associated with a preferred transmit power, that is, a preferred power weight received from the serving base station.
- the neighboring base station may precode at least one data symbol based on the determined phase shift matrix and the precoding matrix.
- a transmit power of the precoded at least one data symbol may be adjusted according to the determined power weight.
Landscapes
- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
- Physics & Mathematics (AREA)
- Mathematical Physics (AREA)
- Power Engineering (AREA)
- Mobile Radio Communication Systems (AREA)
- Radio Transmission System (AREA)
Abstract
Description
Claims (20)
- A method of operating a serving base station for a multi-cell cooperative communication in cooperation with at least one neighboring base station, the method comprising:generating a precoding matrix based on a plurality of codeword matrices;providing a phase shift matrix to shift a phase of at least one element among elements included in the precoding matrix; andprecoding at least one data symbol using the phase shift matrix and the precoding matrix.
- The method of claim 1, further comprising:adjusting a transmit power of the precoded at least one data symbol.
- The method of claim 2, wherein the adjusting comprises adaptively adjusting the transmit power of the precoded at least one data symbol based on at least one of a channel between the at least one neighboring base station and a terminal, a channel between the serving base station and the terminal, and an achievable capacity of the terminal.
- The method of claim 1, wherein the providing comprises adaptively providing the phase shift matrix based on at least one of a channel between the at least one neighboring base station and a terminal, a channel between the serving base station and the terminal, and an achievable capacity of the terminal.
- The method of claim 1, wherein the providing comprises generating the phase shift matrix based on an effective channel between the at least one neighboring base station and a terminal or an effective channel between the at least one neighboring base station the serving base station and the terminal with respect to each of the at least one data symbol.
- The method of claim 1, wherein the providing comprises providing the phase shift matrix using a plurality of candidate matrices pre-stored in a memory.
- The method of claim 1, further comprising:receiving, from a terminal, information associated with a preferred phase shift matrix,wherein the providing comprises providing the phase shift matrix based on information associated with the preferred phase shift matrix.
- The method of claim 1, wherein the providing comprises providing the phase shift matrix in a form of a diagonal matrix.
- The method of claim 2, further comprising:transferring, to the at least one neighboring base station, information associated with the phase shift matrix, information associated with the precoding matrix, or information associated with the transmit power.
- A method of operating a terminal for a multi-cell cooperative communication through a mutual cooperation between at least one neighboring base station and a servicing base station, the method comprising:driving a memory storing a plurality of candidate matrices;generating information associated with a preferred phase shift matrix among the plurality of candidate matrices, so that the at least one neighboring base station or the serving base station uses a phase shift matrix to shift a phase of at least on element among elements included in a precoding matrix; andfeeding back, to the at least one neighboring base station or the serving base station, information associated with the preferred phase shift matrix.
- The method of claim 10, wherein the generating comprises generating information associated with the preferred phase shift matrix based on an achievable capacity.
- The method of claim 10, wherein the generating comprises generating information associated with the preferred phase shift matrix based on an effective channel between the at least one neighboring base station and a terminal or an effective channel between the serving base station and the terminal with respect to each of at least one data symbol that the at least one neighboring base station or the serving base station desires to precode.
- The method of claim 10, further comprising:feeding back, to the at least one neighboring base station or the serving base station, information associated with a preferred power weight so that the at least one neighboring base station or the serving base station adjusts a transmit power of at least one data symbol.
- A serving base station for a multi-cell cooperative communication in cooperation with at least one neighboring base station, the serving base station comprising:a memory to store a plurality of codeword matrices and a plurality of candidate matrices;a precoding matrix generator to generate a precoding matrix based on the plurality of codeword matrices stored in the memory;a phase shift matrix providing unit to provide a phase shift matrix based on the plurality of candidate matrices in order to shift a phase of at least one element among elements included in the precoding matrix; anda precoder to precode at least one data symbol using the phase shift matrix and the precoding matrix.
- The serving base station of claim 14, further comprising:an information receiver to receive, from a terminal, information associated with a preferred phase shift matrix; anda power weight adjustment unit to adjust a power weight based on information associated with a preferred power weight, fed back from the terminal, in order to adjust a transmit power of the precoded at least one data symbol,wherein the phase shift matrix providing unit provides the phase shift matrix based on information associated with the preferred phase shift matrix.
- A terminal for a multi-cell cooperative communication performed through a mutual cooperation between at least one neighboring base station and a serving base station, the terminal comprising:a memory to store a plurality of codeword matrices and a plurality of candidate matrices that are used to feed back information associated with a preferred precoding matrix;an information generator to generate information associated with a preferred phase shift matrix among the plurality of candidate matrices, so that the at least one neighboring base station or the serving base station uses a phase shift matrix to shift a phase of at least one element among elements included in the precoding matrix; andan information feedback unit to feed back, to the at least one neighboring base station or the serving base station, information associated with the preferred phase shift matrix.
- The terminal of claim 16, wherein the information generator comprises a decision unit to determine the preferred phase shift matrix after determining at least one of a number of preferred data symbols and the preferred precoding matrix.
- A method of operating a neighboring base station for a multi-cell cooperative communication in cooperation with a serving base station, the method comprising:receiving, from the serving base station, information regarding a phase shift matrix and a precoding matrix; andprecoding at least one data symbol that the serving base station desires to transmit using the phase shift matrix and the precoding matrix.
- The method of claim 18, further comprising:extracting the phase shift matrix from a plurality of candidate matrices pre-stored in a memory, based on information associated with the phase shift matrix.
- The method of claim 18, further comprising:receiving information associated with a transmit power from the serving base station; andadjusting a transmit power of the precoded at least one data symbol based on information associated with the transmit power.
Priority Applications (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP09808377.7A EP2316171A4 (en) | 2008-08-18 | 2009-08-14 | Communication system including base stations and terminal for multi-cell cooperative communication |
JP2011523734A JP5762959B2 (en) | 2008-08-18 | 2009-08-14 | Communication system including base station and terminal for multi-cell cooperative communication |
CN200980141404.XA CN102239646B (en) | 2008-08-18 | 2009-08-14 | For the communication system comprising base station and terminal of multiple cell cooperative communication |
US13/059,903 US8660601B2 (en) | 2008-08-18 | 2009-08-14 | Communication system including base stations and terminal for multi-cell cooperative communication |
Applications Claiming Priority (6)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
KR10-2008-0080454 | 2008-08-18 | ||
KR20080080454 | 2008-08-18 | ||
KR10-2008-0093586 | 2008-09-24 | ||
KR20080093586 | 2008-09-24 | ||
KR10-2009-0062450 | 2009-07-09 | ||
KR1020090062450A KR101268687B1 (en) | 2008-08-18 | 2009-07-09 | Communication system including basestations and terminal for multi-cell cooperative communication |
Publications (2)
Publication Number | Publication Date |
---|---|
WO2010021471A2 true WO2010021471A2 (en) | 2010-02-25 |
WO2010021471A3 WO2010021471A3 (en) | 2011-08-11 |
Family
ID=42091472
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/KR2009/004548 WO2010021471A2 (en) | 2008-08-18 | 2009-08-14 | Communication system including base stations and terminal for multi-cell cooperative communication |
Country Status (6)
Country | Link |
---|---|
US (1) | US8660601B2 (en) |
EP (1) | EP2316171A4 (en) |
JP (1) | JP5762959B2 (en) |
KR (2) | KR101268687B1 (en) |
CN (1) | CN102239646B (en) |
WO (1) | WO2010021471A2 (en) |
Cited By (12)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN102377527A (en) * | 2010-08-09 | 2012-03-14 | 上海贝尔股份有限公司 | Method and device for decreasing multi-cell feedback overhead |
WO2012014064A3 (en) * | 2010-06-24 | 2012-03-22 | Alcatel Lucent | Method and device for obtaining precoding matrix |
CN102447534A (en) * | 2010-10-13 | 2012-05-09 | 中兴通讯股份有限公司 | Data transmission method and system of multiple-input multiple-output (MIMO) system |
JP2012209742A (en) * | 2011-03-29 | 2012-10-25 | Sharp Corp | Base station device, terminal device, communication system, and communication method |
CN102761354A (en) * | 2011-04-28 | 2012-10-31 | 上海贝尔股份有限公司 | Method and device for generating codebook and related data in network equipment |
JP2013516933A (en) * | 2010-01-11 | 2013-05-13 | チャイナ アカデミー オブ テレコミュニケーションズ テクノロジー | Method and apparatus for transmitting and receiving information in a multi-antenna system, and multi-antenna system |
GB2514111A (en) * | 2013-05-13 | 2014-11-19 | British Broadcasting Corp | Transmission techniques |
EP2589252A4 (en) * | 2010-04-29 | 2017-05-10 | Nokia Solutions and Networks Oy | Systems and methods for coordinating the scheduling of beamformed data to reduce interference |
CN107436602A (en) * | 2017-07-05 | 2017-12-05 | 深圳大学 | The position control method and device of mobile device based on single bit feedback |
JP2018170767A (en) * | 2011-04-19 | 2018-11-01 | サン パテント トラスト | Signal generation method and signal generation device |
JP2019092204A (en) * | 2011-02-18 | 2019-06-13 | サン パテント トラスト | Signal generation method and signal generating device |
CN112104585A (en) * | 2020-11-09 | 2020-12-18 | 电子科技大学 | Phase domain modulation method dependent on spatial position |
Families Citing this family (11)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
KR101268687B1 (en) * | 2008-08-18 | 2013-05-29 | 한국전자통신연구원 | Communication system including basestations and terminal for multi-cell cooperative communication |
US8676133B2 (en) * | 2008-09-19 | 2014-03-18 | Qualcomm Incorporated | Reference signal design for LTE A |
TWI429216B (en) * | 2009-10-02 | 2014-03-01 | Mediatek Inc | Concatenating precoder selection for ofdma-based multi-bs mimo |
KR20120085998A (en) * | 2011-01-25 | 2012-08-02 | 삼성전자주식회사 | Method and apparatus for interference mitigation in heterogeneous network using beamforming |
US8929473B2 (en) * | 2011-07-28 | 2015-01-06 | Samsung Electronics Co., Ltd. | Combining baseband processing and radio frequency beam steering in wireless communication systems |
US8478203B2 (en) * | 2011-07-31 | 2013-07-02 | Xiao-an Wang | Phase synchronization of base stations via mobile feedback in multipoint broadcasting |
WO2014112749A1 (en) * | 2013-01-18 | 2014-07-24 | 엘지전자 주식회사 | Interference-removed reception method and terminal |
KR102235686B1 (en) | 2013-12-30 | 2021-04-06 | 한국전자통신연구원 | Method for eliminating signal interference based on multiple input multiple output |
WO2016124457A1 (en) * | 2015-02-02 | 2016-08-11 | Telefonaktiebolaget Lm Ericsson (Publ) | Selective codeword-to-layer mapping for mimo transmissions |
US10110357B2 (en) * | 2016-11-03 | 2018-10-23 | Industrial Technology Research Institute | Cooperative communication method and system |
TWI633802B (en) * | 2016-11-03 | 2018-08-21 | 財團法人工業技術研究院 | Cooperative communication method and system |
Family Cites Families (33)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP3884774B2 (en) * | 1997-04-17 | 2007-02-21 | 株式会社エヌ・ティ・ティ・ドコモ | Base station apparatus in mobile communication system |
TW396686B (en) * | 1997-06-06 | 2000-07-01 | Ericsson Telefon Ab L M | Modified downlink power control during macrodiversity |
KR100640349B1 (en) * | 2003-01-02 | 2006-10-30 | 삼성전자주식회사 | Transmitting and receiving apparatus for wireless telecommunication system having 3 transmit antennas |
KR100938095B1 (en) | 2003-11-19 | 2010-01-21 | 삼성전자주식회사 | Apparatus and method for generating a preamble sequence in an orthogonal frequency division multiplexing communication system |
KR101231357B1 (en) * | 2006-04-06 | 2013-02-07 | 엘지전자 주식회사 | Channel status information feedback method and data transmission method for multiple antenna system |
US7526036B2 (en) * | 2006-04-20 | 2009-04-28 | Mitsubishi Electric Research Laboratories, Inc. | System and method for transmitting signals in cooperative base station multi-user mimo networks |
KR20070113967A (en) * | 2006-05-26 | 2007-11-29 | 엘지전자 주식회사 | Phase shift based precoding method and tranceiver supporting the same |
TWI343200B (en) * | 2006-05-26 | 2011-06-01 | Lg Electronics Inc | Method and apparatus for signal generation using phase-shift based pre-coding |
EP2249486A3 (en) * | 2006-08-18 | 2011-12-07 | NTT DoCoMo, Inc. | Transmitter/receiver for communicating with a remote transmitter/receiver using spatial phase codes |
KR20080026010A (en) | 2006-09-19 | 2008-03-24 | 엘지전자 주식회사 | Data transmitting method using phase-shift based precoding and tranceiver implementing the same |
US8503560B2 (en) * | 2006-10-02 | 2013-08-06 | Samsung Electronics Co., Ltd | System and method for performing precoding in a wireless communication system |
KR20080036493A (en) * | 2006-10-23 | 2008-04-28 | 엘지전자 주식회사 | Network access method in mobile communication system and terminal supporting the same |
KR20080040543A (en) | 2006-11-02 | 2008-05-08 | 엘지전자 주식회사 | Method for transmitting data using phase shift based precoding and tranceiver supporting the same |
CN100553184C (en) * | 2006-11-24 | 2009-10-21 | 普天信息技术研究院 | A kind of signal precoding method |
MX2009007986A (en) * | 2007-02-06 | 2009-08-07 | Qualcomm Inc | Mimo transmission with explicit and implicit cyclic delays. |
US8509710B2 (en) * | 2007-02-06 | 2013-08-13 | Qualcomm Incorporated | MIMO transmission with explicit and implicit cyclic delays |
US8068555B2 (en) * | 2007-02-13 | 2011-11-29 | Telefonaktiebolaget L M Ericsson (Publ) | Methods and systems for combined cyclic delay diversity and precoding of radio signals |
KR20080076683A (en) | 2007-02-14 | 2008-08-20 | 엘지전자 주식회사 | Phase shift based precoding method and tranceiver supporting the same |
KR100980647B1 (en) * | 2007-07-05 | 2010-09-07 | 삼성전자주식회사 | Apparatus and method for interference cancellation in multi-antenna system |
US8131228B2 (en) * | 2007-08-01 | 2012-03-06 | Telefonaktiebolaget Lm Ericsson (Publ) | Interference based phase shift precoding for OFDM |
KR101306713B1 (en) * | 2007-08-14 | 2013-09-11 | 엘지전자 주식회사 | Method for feedback and Method for configuring a codebook in multi antenna system |
WO2009051748A2 (en) * | 2007-10-15 | 2009-04-23 | Marvell World Trade Ltd. | Beamforming using predefined spatial mapping matrices |
KR101430476B1 (en) * | 2008-03-24 | 2014-08-18 | 엘지전자 주식회사 | A method for transmitting and receiving precoded signal in MIMO communication system |
KR101527009B1 (en) * | 2008-07-11 | 2015-06-18 | 엘지전자 주식회사 | A method for multi-cell mimo under multi cell environment |
KR101268687B1 (en) * | 2008-08-18 | 2013-05-29 | 한국전자통신연구원 | Communication system including basestations and terminal for multi-cell cooperative communication |
KR101481589B1 (en) * | 2008-08-25 | 2015-01-12 | 엘지전자 주식회사 | Method of feedback information transmition, method and apparatus of data transmition in a wireless communication system having multiple antennas |
US8442566B2 (en) * | 2009-01-07 | 2013-05-14 | Samsung Electronics Co., Ltd. | Coordinated multipoint (CoMP) joint transmission using channel information feedback and higher rank dedicated beam-forming |
US8358718B2 (en) * | 2009-04-02 | 2013-01-22 | Samsung Electronics Co., Ltd. | Apparatus and method for determining optimum integer perturbation vector of low complexity in multiple antenna system |
US8412275B2 (en) * | 2009-12-30 | 2013-04-02 | Broadcom Corporation | Method and system for communicating feedback information in a multiple user multiple input multiple output (MU-MIMO) communication system |
US9282541B2 (en) * | 2010-04-14 | 2016-03-08 | Lg Electronics Inc. | Method in which a terminal cooperates with another terminal to transmit data, and method for receiving the data |
US8855577B2 (en) * | 2011-01-21 | 2014-10-07 | Futurewei Technologies, Inc. | System and method for assisted open loop multiple input, multiple output communications |
US8798558B2 (en) * | 2011-01-27 | 2014-08-05 | Commonwealth Scientific And Industrial Research Organisation | Reducing out-of-band emission |
US20120282936A1 (en) * | 2011-05-02 | 2012-11-08 | Research In Motion Limited | Methods of PDCCH Capacity Enhancement in LTE Systems |
-
2009
- 2009-07-09 KR KR1020090062450A patent/KR101268687B1/en active IP Right Grant
- 2009-08-14 CN CN200980141404.XA patent/CN102239646B/en not_active Expired - Fee Related
- 2009-08-14 EP EP09808377.7A patent/EP2316171A4/en not_active Withdrawn
- 2009-08-14 US US13/059,903 patent/US8660601B2/en active Active
- 2009-08-14 WO PCT/KR2009/004548 patent/WO2010021471A2/en active Application Filing
- 2009-08-14 JP JP2011523734A patent/JP5762959B2/en active Active
-
2012
- 2012-06-18 KR KR1020120064764A patent/KR20120086279A/en not_active Application Discontinuation
Non-Patent Citations (1)
Title |
---|
See references of EP2316171A4 * |
Cited By (27)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2013516933A (en) * | 2010-01-11 | 2013-05-13 | チャイナ アカデミー オブ テレコミュニケーションズ テクノロジー | Method and apparatus for transmitting and receiving information in a multi-antenna system, and multi-antenna system |
EP2589252A4 (en) * | 2010-04-29 | 2017-05-10 | Nokia Solutions and Networks Oy | Systems and methods for coordinating the scheduling of beamformed data to reduce interference |
WO2012014064A3 (en) * | 2010-06-24 | 2012-03-22 | Alcatel Lucent | Method and device for obtaining precoding matrix |
US8831126B2 (en) | 2010-06-24 | 2014-09-09 | Alcatel Lucent | Method and device for obtaining precoding matrix |
CN102377527B (en) * | 2010-08-09 | 2014-12-24 | 上海贝尔股份有限公司 | Method and device for decreasing multi-cell feedback overhead |
WO2012020309A3 (en) * | 2010-08-09 | 2012-04-26 | Alcatel Lucent | Method and apparatus for decreasing multi-cell feedback overhead |
CN102377527A (en) * | 2010-08-09 | 2012-03-14 | 上海贝尔股份有限公司 | Method and device for decreasing multi-cell feedback overhead |
CN102447534A (en) * | 2010-10-13 | 2012-05-09 | 中兴通讯股份有限公司 | Data transmission method and system of multiple-input multiple-output (MIMO) system |
CN102447534B (en) * | 2010-10-13 | 2014-04-09 | 中兴通讯股份有限公司 | Data transmission method and system of multiple-input multiple-output (MIMO) system |
JP7117506B2 (en) | 2011-02-18 | 2022-08-15 | サン パテント トラスト | SIGNAL GENERATING METHOD AND SIGNAL GENERATING DEVICE |
JP2019092204A (en) * | 2011-02-18 | 2019-06-13 | サン パテント トラスト | Signal generation method and signal generating device |
JP2021121105A (en) * | 2011-02-18 | 2021-08-19 | サン パテント トラスト | Signal generation method and signal generating device |
US20140011493A1 (en) * | 2011-03-29 | 2014-01-09 | Sharp Kabushiki Kaisha | Base station device, terminal device, communication system, and communication method |
JP2012209742A (en) * | 2011-03-29 | 2012-10-25 | Sharp Corp | Base station device, terminal device, communication system, and communication method |
JP2021007221A (en) * | 2011-04-19 | 2021-01-21 | サン パテント トラスト | Signal generation method and signal generation device |
JP2019198083A (en) * | 2011-04-19 | 2019-11-14 | サン パテント トラスト | Signal generation method and signal generation device |
JP2018170767A (en) * | 2011-04-19 | 2018-11-01 | サン パテント トラスト | Signal generation method and signal generation device |
WO2012146982A1 (en) * | 2011-04-28 | 2012-11-01 | Alcatel Lucent | Method and apparatus for generating codebooks and associated data in a network device |
US9184952B2 (en) | 2011-04-28 | 2015-11-10 | Alcatel Lucent | Method and apparatus for generating codebooks and associated data in a network device |
CN102761354B (en) * | 2011-04-28 | 2015-02-18 | 上海贝尔股份有限公司 | Method and device for generating codebook and related data in network equipment |
CN102761354A (en) * | 2011-04-28 | 2012-10-31 | 上海贝尔股份有限公司 | Method and device for generating codebook and related data in network equipment |
US10396869B2 (en) | 2013-05-13 | 2019-08-27 | British Broadcasting Corporation | Transmission techniques |
WO2014184540A1 (en) * | 2013-05-13 | 2014-11-20 | British Broadcasting Corporation | Precoding techniques for optimized channel capacity in mimo systems |
GB2514111A (en) * | 2013-05-13 | 2014-11-19 | British Broadcasting Corp | Transmission techniques |
CN107436602A (en) * | 2017-07-05 | 2017-12-05 | 深圳大学 | The position control method and device of mobile device based on single bit feedback |
CN112104585A (en) * | 2020-11-09 | 2020-12-18 | 电子科技大学 | Phase domain modulation method dependent on spatial position |
CN112104585B (en) * | 2020-11-09 | 2021-03-26 | 电子科技大学 | Phase domain modulation method dependent on spatial position |
Also Published As
Publication number | Publication date |
---|---|
CN102239646A (en) | 2011-11-09 |
CN102239646B (en) | 2016-02-10 |
WO2010021471A3 (en) | 2011-08-11 |
EP2316171A4 (en) | 2014-06-18 |
JP2012500550A (en) | 2012-01-05 |
KR20120086279A (en) | 2012-08-02 |
KR101268687B1 (en) | 2013-05-29 |
JP5762959B2 (en) | 2015-08-12 |
US8660601B2 (en) | 2014-02-25 |
EP2316171A2 (en) | 2011-05-04 |
US20110151918A1 (en) | 2011-06-23 |
KR20100021966A (en) | 2010-02-26 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
WO2010021471A2 (en) | Communication system including base stations and terminal for multi-cell cooperative communication | |
WO2017192025A1 (en) | Method and apparatus for transmitting harq-ack feedback information | |
WO2015020464A1 (en) | Method and apparatus for transmitting and receiving feedback information in mobile communication system based on 2 dimensional massive mimo | |
WO2011005045A2 (en) | Method for sending and receiving data on a cooperative communications system and a cooperative communications method | |
WO2010085092A2 (en) | Method and apparatus of transmitting data in coordinated multi-cell wireless communication system | |
WO2012093742A1 (en) | Terminal and base station, method thereof in wireless communication system | |
WO2016163855A1 (en) | Method for multiplexing uplink information | |
WO2011040792A2 (en) | Lte-a system and uplink power control method thereof | |
WO2015178711A1 (en) | Channel state information feedback method and apparatus for 2-dimensional massive mimo communication system | |
WO2013157815A1 (en) | Apparatus and method for controlling uplink power control in communication system | |
WO2014010841A1 (en) | Controlling transmit power of uplink sounding reference signal | |
WO2012093904A2 (en) | Interference alignment method and device in cellular network | |
WO2011099756A2 (en) | Unified feedback frame for supporting a plurality of feedback modes and a multiple-input multiple-output (mimo) communication system using the unified feedback frame | |
WO2011087227A2 (en) | Communication apparatus and precoding method based on multiple cells and multiple users | |
WO2011139081A2 (en) | Apparatus and method for transmitting and receiving of cyclic shift parameter for supporting orthogonality in mimo environment | |
WO2010101345A2 (en) | Signal transmission method and system for transmitting signal by using interference control method and/or transmission power control method | |
WO2011056027A2 (en) | Techniques for transformation codebook antenna beamforming in ofdm wireless communication system | |
WO2011083945A2 (en) | Multiple-input multiple-output (mimo) communication system using a codebook and method of designing the codebook | |
WO2013032294A2 (en) | Multiple antenna transmission with per-antenna power constraints | |
WO2014003256A1 (en) | Communication system using interference alignment in multi-cell environment | |
WO2015050421A1 (en) | Method and device for estimating channel in wireless communication system | |
WO2020009432A1 (en) | Method and device for performing beamforming in wireless communication system | |
WO2011093687A2 (en) | Apparatus and method for allocating channel and power in communication system | |
WO2014109538A1 (en) | Method for eliminating interference between cells in wireless communications system and apparatus therefor | |
WO2017069580A1 (en) | Precoder codebook for advanced wireless communication systems |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
WWE | Wipo information: entry into national phase |
Ref document number: 200980141404.X Country of ref document: CN |
|
121 | Ep: the epo has been informed by wipo that ep was designated in this application |
Ref document number: 09808377 Country of ref document: EP Kind code of ref document: A2 |
|
ENP | Entry into the national phase |
Ref document number: 2011523734 Country of ref document: JP Kind code of ref document: A |
|
WWE | Wipo information: entry into national phase |
Ref document number: 13059903 Country of ref document: US |
|
NENP | Non-entry into the national phase |
Ref country code: DE |
|
WWE | Wipo information: entry into national phase |
Ref document number: 2009808377 Country of ref document: EP |