CN105324953A

CN105324953A - Method for determining downlink channel precoding matrix, base station, and user equipment

Info

Publication number: CN105324953A
Application number: CN201380076803.9A
Authority: CN
Inventors: 戎璐; 陈大庚
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2013-09-16
Filing date: 2013-09-16
Publication date: 2016-02-10
Anticipated expiration: 2033-09-16
Also published as: CN105324953B; WO2015035645A1

Abstract

Embodiments of the present invention provide a method for determining a downlink channel precoding matrix, a base station, and a user equipment (UE). In the method provided in this embodiment, a base station sends a downlink reference signal to each UE, so that each UE performs channel estimation to acquire a downlink channel matrix Hi, determines Ki feedback precoding matrices according to the downlink channel matrix Hi, and adopts a reverse precoding matrix to perform precoding on an uplink reference signal and then returns Ki feedback reference signals to the base station, and the base station determines a downlink precoding matrix of each UE according to Ki reference signals returned by each UE. Because each UE only needs to return Ki uplink feedback reference signals to perform channel estimation, and the number Ki of the uplink feedback reference signals is smaller than or equal to the number of antennas of the UE; and therefore, a feedback overhead of an uplink reference signal can be reduced, so as to improve a spectrum utilization rate.

Description

Method for determining downlink channel precoding matrix, base station, and user equipment

Determination method, base station and the user equipment of down channel pre-coding matrix

Technical field

The present embodiments relate to data communication technology, more particularly to a kind of determination method, base station and the user equipment of down channel pre-coding matrix.Background technology

The fast development of requirements of mobile subscribers, higher and higher requirement is put forward to the capacity of mobile communications network, and an effective way for improving mobile communications network is to improve spectrum efficiency.Multiple-input and multiple-output (Multiple-Input Multiple-Output, abbreviation MIMO) antenna technology, the capacity of mobile communications network can be improved, the receptivity of system can be effectively improved using precoding technique in mimo system, in order to obtain the pre-coding matrix of down channel, need to send substantial amounts of reference signal and feedback signal in the air, available frequency spectrum resource is consumed in large quantities.

In the prior art, a kind of mode is, base station and user equipment（User Equipment, referred to as

UE a set of precoding codebook can) be arranged in advance.UE is according to its measurement result, from this set code book, chooses suitable pre-coding matrix, and the sequence number to the base station feedback pre-coding matrix in the codebook.The sequence number that base station is fed back according to UE, you can determine the pre-coding matrix that UE is fed back.One reverse side, the antenna amount of base station is bigger, and the dimension of pre-coding matrix is bigger, and the error of introducing is also more, therefore performance loss can be bigger.On the other hand, with the increase of antenna for base station quantity, pre-coding matrix quantity in code book with antenna amount rather than will be linearly increased, therefore feedback overhead can be increased rapidly.In another way, in tdd mode, it is possible to use channel reciprocity, UE every antenna sends detection reference signal respectively（Sounding Reference Signa, abbreviation SRS), the SRS that base station is sent according to UE measures mimo channel, and then base station can just calculate suitable pre-coding matrix accordingly.Because SRS is the reference signal for channel measurement, and in order to accurately measure frequency-selective channel, SRS pilot tone needs are very intensive, therefore the expense of SRS consumption is very big.In order to measure complete MIMO channels, UE every antenna will send SRS respectively, therefore with the growth of UE antenna amounts, and the expense of SRS consumption also can further linear increase.

The content of the invention The embodiment of the present invention provides a kind of determination method, base station and the user equipment of down channel pre-coding matrix, to reduce the expense for sending uplink feedback reference signal, improves the utilization rate of frequency spectrum resource.

First aspect present invention provides a kind of determination method of down channel pre-coding matrix, including：Base station sends downlink reference signal to each user equipment (UE), so that each UE carries out down channel matrix H i (i=l that channel estimation obtains down channel according to the downlink reference signal, 2 ... I), I is the quantity of UE in cell, and Ki feedback precoding vector is determined according to the down channel matrix H i, wherein, the down channel matrix H i is matrix, M is the antenna number that the base station is used, Ni is the antenna number that i-th of UE is used, M and Ni is positive integer, Ki is the quantity for the feedback reference signal that i-th UE need to be sent, 1≤≤ π ι (Μ, Λ ^, the feedback precoding vector is matrix；

The base station receives the Ki feedback reference signal that each UE is sent, wherein, each UE feedback reference signal is that the UE is obtained according to corresponding feedback precoding vector to uplink reference signals progress precoding processing；

The base station according to the feedback reference signal of each UE, or, the base station determines the downlink precoding matrix of each UE according to each each UE feedback reference signal and other UE up precoding reference signal.

In the first possible implementation of first aspect present invention, the base station is according to the feedback reference signal of each UE, or, the base station is according to the feedback reference signal of each UE and other UE up precoding reference signal, the downlink precoding matrix of each UE is determined, including：

The base station carries out channel estimation respectively according to the Ki feedback reference signal of each UE, determine the corresponding Ki up precoding vector h of each UE, wherein, h is i-th of UE k-th of up precoding vector, k=l, 2 ... Ki, h are Μ χ matrixes；

The base station is according to the corresponding Ki up precoding vector h of each UE_Lk, the feeding back precoding matrix of each UE is determined, wherein, the feeding back precoding matrix is MxKi matrix;The base station according to the feeding back precoding matrix of each UE, or, the base station determines the downlink precoding matrix of each UE according to the feeding back precoding matrix of each UE and other UE feeding back precoding matrix.

In second of possible implementation of first aspect present invention, the feeding back precoding matrix of each UE is determined in the base station according to the corresponding Ki up precoding vector h of each UE, Including：

Ki up precoding vector corresponding to each UE is normalized respectively for the base station, and determines according to the Ki up ^ of precoding vector 1 after each UE normalizeds the feeding back precoding matrix of each UE.

With reference to the first and second possible implementation of first aspect present invention, in the third possible implementation of first aspect present invention, the base station is according to the feeding back precoding matrix of each UE and other UE feeding back precoding matrix, the downlink precoding matrix of each UE is determined, including：

The base station combines the feeding back precoding matrix of each UE, obtain joint feeding back precoding matrix R, R=[QU, wherein, represent i-th of UE feeding back precoding matrix;The base station determines the downlink precoding matrix P of each UE according to below equation:

P = ( R R^H) R, R^hR conjugate matrices are represented,（X) represent to matrix X finding the inverse matrix computings.

In the 4th kind of possible implementation of first aspect present invention, the base station is sent to each user equipment (UE) before downlink reference signal, in addition to：

The base station notifies that each UE sends the feedback reference signal on specified running time-frequency resource position, and the feedback reference signal quantity.

In the 5th kind of possible implementation of first aspect present invention, the base station notifies that each UE sends the up reference information on specified running time-frequency resource position, and the up reference information quantity K, including：

The base station sends reference signal to each UE and indicates message, and the reference signal indicates to send the running time-frequency resource position of the feedback reference signal in message comprising the UE, and the feedback reference signal quantity.

In the 6th kind of possible implementation of first aspect present invention, the base station notifies that each UE sends the feedback reference signal on specified running time-frequency resource position, and the feedback reference signal quantity Κ, including：

Total running time-frequency resource that the base station takes to each UE feedback reference signals for sending the UE, and the running time-frequency resource of the occupancy of each feedback reference signal of the UE, so that total running time-frequency resource and the running time-frequency resource of the occupancy of each feedback reference signal that each UE takes according to the feedback reference signal determine the quantity Κ of the feedback reference signal. Second aspect of the present invention provides a kind of determination method of down channel pre-coding matrix, including：User equipment (UE) receives the downlink reference signal that base station is sent, the down channel matrix H that channel estimation obtains down channel is carried out according to the downlink reference signal, wherein, the down channel matrix H is NxM matrixes, M is the antenna number that the base station is used, N is the antenna number that the UE is used, and M and N are positive integer；

The UE determines K feedback precoding vector according to the down channel matrix H, wherein, K is the quantity for the feedback reference signal that the UE need to be sent, and l≤≤ min (M, N), the feedback precoding vector is Nx l matrixes；

The UE carries out precoding processing to uplink reference signals respectively, obtains K feedback reference signal according to described K feedback precoding vector；

The UE sends the K feedback reference signal to the base station, so that the base station determines the downlink precoding matrix of the UE according to the K feedback reference signal.

In the first possible implementation of second aspect of the present invention, the UE determines K feedback precoding vector according to the down channel matrix H, including：

The UE carries out singular value decomposition to the down channel matrix H, obtains H_D = U∑V^H, wherein, U is Ν χ Ν unitary matrice, and V is Μ χ Μ unitary matrice, and ∑ is NxM diagonal matrix；

The K of matrix U is taken to arrange as described K feedback precoding vector, or, take any K of matrix U to arrange and carry out linear combination, obtain the K feedback precoding vector.

In second of possible implementation of second aspect of the present invention, the UE determines K feedback precoding vector according to the down channel matrix H, including：

The UE is by HH^HEigenvalues Decomposition is carried out, is obtained Z USUH, wherein, H^HRepresenting matrix H conjugate matrices, U is NxN unitary matrice, and ∑ is NxM diagonal matrix, U^HFor the conjugate matrices of matrix U；

In the third possible implementation of second aspect of the present invention, the UE determines K feedback precoding vector according to the down channel matrix H, including：

The UE determines the K rear coding vectors of the down channel H according to the down channel H；Precoding vector is fed back using the transposition of coding vector after the K of the down channel H as described K of H, or takes any K of the transposition of coding vector after K of down channel H Row carry out linear combination, obtain the κ feedback precoding vector.

With reference to second aspect of the present invention and second aspect the first to the third possible implementation, in the 4th kind of possible implementation of second aspect of the present invention, the UE according to the down channel matrix H determine K feedback precoding vector before, in addition to：

The UE obtains the quantity K of the running time-frequency resource position for sending the up precoding reference signal and the uplink reference signals.

With reference to second aspect of the present invention and second aspect the first to the 4th kind of possible implementation, in the 5th kind of possible implementation of second aspect of the present invention, the UE is according to described Κ feedback precoding vector, precoding processing is carried out to uplink reference signals respectively, Κ feedback reference signal is obtained, including：

The UE carries out precoding processing according to below equation according to described Κ feedback precoding vector to uplink reference signals： i⁼ ∑^w(» )(")

M wherein ,/_nRepresent time resource position, k_nFrequency resource position is represented, p represents the antenna serial number of the UE, and β represents amplitude adjusted coefficient, r^(m)Represent that m-th of uplink reference signals uses sequence of complex numbers, r^(m)(n) n-th of plural elements of the sequence of complex numbers, w are represented^(m)Represent the precoding vector that m-th of feedback reference signal is used, l≤m≤K, w^(m)(p) p-th of plural elements of the precoding vector that m-th of uplink reference signals are used are represented.Third aspect present invention provides a kind of base station, including：

Sending module, for sending downlink reference signal to each user equipment (UE), so that each UE carries out the down channel matrix that channel estimation obtains down channel according to the downlink reference signal

(i=l, 2 ... I), I is the quantity of UE in cell, and Ki feedback precoding vector is determined according to the down channel matrix H i, wherein, the down channel matrix H i is matrix, M is the antenna number that the base station is used, Ni is the antenna number that i-th of UE is used, M and Ni is positive integer, and Ki is the quantity for the feedback reference signal that i-th of UE need to be sent, 1≤≤ π ι (Μ, Λ ^, the feedback precoding vector is NiX l matrixes；

Receiving module, for receiving the Ki feedback reference signal that each UE is sent, wherein, each UE feedback reference signal is that the UE is obtained according to corresponding feedback precoding vector to uplink reference signals progress precoding processing； Pre-coding matrix determining module, for the feedback reference signal according to each UE, or, according to the up precoding reference signal of each each UE feedback reference signal and other UE, determine the downlink precoding matrix of each UE.

In the first possible implementation of third aspect present invention, the pre-coding matrix determining module includes：

Up precoding vector determining unit, channel estimation is carried out respectively for the Ki feedback reference signal according to each UE, determine the corresponding Ki up precoding vector h of each UE, wherein, 1 ^ is i-th of UE k-th of up precoding vector, k=l, 2 ... Ki, h are Μ χ matrixes；

Feeding back precoding matrix determining unit, for according to the corresponding Ki up precoding vector h of each UE, determining the feeding back precoding matrix of each UE, wherein, the feeding back precoding matrix is MxKi matrix；

Downlink precoding matrix determining unit, for the feeding back precoding matrix according to each UE, or, according to the feeding back precoding matrix of each UE and other UE feeding back precoding matrix, determine the downlink precoding matrix of each UE.

In second of possible implementation of third aspect present invention, the feeding back precoding matrix determining unit specifically for：

Ki up precoding vector corresponding to each UE is normalized, and according to Ki up precoding vectors after each UE normalizeds!^ determines the feeding back precoding matrix of each UE.

With reference to the first and second possible implementation of third aspect present invention, in the third possible implementation of third aspect present invention, the downlink precoding matrix determining unit specifically for：

The feeding back precoding matrix of each UE is combined, joint feeding back precoding matrix R, R=[Q is obtained_{1 ?}Q₂... Q, wherein, represent i-th of UE feeding back precoding matrix；

The downlink precoding matrix P of each UE is determined according to below equation:

In the 4th kind of possible implementation of third aspect present invention, the sending module is additionally operable to： Notify that each UE sends the feedback reference signal on specified running time-frequency resource position, and the feedback reference signal quantity K.

In the 5th kind of possible implementation of third aspect present invention, the sending module specifically for：

Send reference signal to each UE and indicate message, the reference signal indicates to send the running time-frequency resource position of the feedback reference signal in message comprising the UE, and the feedback reference signal quantity Κ.

In the 6th kind of possible implementation of third aspect present invention, the sending module specifically for：

The total running time-frequency resource taken to each UE feedback reference signals for sending the UE, and the running time-frequency resource of the occupancy of each feedback reference signal of the UE, so that total running time-frequency resource and the running time-frequency resource of the occupancy of each feedback reference signal that each UE takes according to the feedback reference signal determine the quantity Κ of the feedback reference signal.

Fourth aspect present invention provides a kind of user equipment (UE), including：

Receiving module, the downlink reference signal for receiving base station transmission；

Down channel matrix deciding module, for carrying out the down channel matrix H that channel estimation obtains down channel according to the downlink reference signal, wherein, the down channel matrix H is NxM matrixes, M is the antenna number that the base station is used, N is the antenna number that the UE is used, and M and N are positive integer；

Precoding vector determining module is fed back, for determining K feedback precoding vector according to the down channel matrix H, wherein, the quantity for the feedback reference signal that K need to be sent for the UE, l≤^≤min (, N)₎The feedback precoding vector is Nx l matrixes；

Precoding processing module, for according to described K feedback precoding vector, carrying out precoding processing to uplink reference signals respectively, obtaining κ feedback reference signal；

Sending module, for sending the K feedback reference signal to the base station, so that the base station determines the downlink precoding matrix of the UE according to the K feedback reference signal.

In the first possible implementation of fourth aspect present invention, it is described feedback precoding vector determining module specifically for：

Singular value decomposition is carried out to the down channel matrix H, H is obtained_D = U∑V^H, wherein, U is NxN unitary matrice, and V is MxM unitary matrice, and ∑ is NxM diagonal matrix； The K of matrix U is taken to arrange as described K feedback precoding vector, or, take any Κ of matrix U to arrange and carry out linear combination, obtain Κ feedback precoding vector.

In second of possible implementation of fourth aspect present invention, it is described feedback precoding vector determining module specifically for：

By Η Η^ΗEigenvalues Decomposition is carried out, H^ HD=U ∑s U is obtained^H, wherein, H^HRepresenting matrix H conjugate matrices, U is NxN unitary matrice, and ∑ is Ν χ Μ diagonal matrix, U^HFor the conjugate matrices of matrix U；

The K of matrix U is taken to arrange as described K feedback precoding vector, or, take any K of matrix U to arrange and carry out linear combination, obtain K feedback precoding vector.

In the third possible implementation of fourth aspect present invention, it is described feedback precoding vector determining module specifically for：

Coding vector after K of the down channel H is determined according to the down channel H；Precoding vector is fed back using the transposition of coding vector after the K of the down channel H as described K of H, or take any K row of the transposition of coding vector after K of down channel H to carry out linear combination, obtain K feedback precoding vector.

With reference to fourth aspect present invention and fourth aspect the first to the third possible implementation, in the 4th kind of possible implementation of fourth aspect present invention, described user equipment also includes：

Acquisition module, the running time-frequency resource position of the up precoding reference signal and the quantity K of the uplink reference signals are sent for obtaining.

With reference to fourth aspect present invention and fourth aspect the first to the 4th kind of possible implementation, in the 5th kind of possible implementation of fourth aspect present invention, the precoding processing module specifically for：

According to described Κ feedback precoding vector, precoding processing is carried out to uplink reference signals according to below equation： i⁼ ∑^w(» )(")

M wherein ,/_nRepresent time resource position, k_nFrequency resource position is represented, p represents the antenna serial number of the UE, and β represents amplitude adjusted coefficient, r^(m)Represent that m-th of uplink reference signals uses sequence of complex numbers, r^(m)(n) n-th of plural elements of the sequence of complex numbers, w are represented^(m)Represent the precoding vector that m-th of feedback reference signal is used, l≤m≤K, w^(m)(p) represent on described m-th The P plural elements of the precoding vector that row reference signal is used.Fifth aspect present invention provides a kind of base station, including：

Transmitter, for sending downlink reference signal to each user equipment (UE), so that each UE carries out down channel matrix H i (i=l that channel estimation obtains down channel according to the downlink reference signal, 2 ... I), I is the quantity of UE in cell, and Ki feedback precoding vector is determined according to the down channel matrix, wherein, the down channel matrix H i is NiXM matrixes, M is the antenna number that the base station is used, Ni is the antenna number that i-th of UE is used, M and Ni is positive integer, Ki is the quantity for the feedback reference signal that i-th of UE need to be sent, 1≤≤ π ι (Μ, Λ ^, the feedback precoding vector is matrix；

Receiver, for receiving the Ki feedback reference signal that each UE is sent, wherein, each UE feedback reference signal is that the UE is obtained according to corresponding feedback precoding vector to uplink reference signals progress precoding processing；

Processor, for the feedback reference signal according to each UE, or, according to the up precoding reference signal of each each UE feedback reference signal and other UE, determine the downlink precoding matrix of each UE.

In the first possible implementation of fifth aspect present invention, the processor specifically for：

Channel estimation is carried out according to the Ki feedback reference signal of each UE respectively, determine the corresponding Ki up precoding vector of each UE wherein, h is i-th of UE k-th of up precoding vector, k=l, 2 ... Ki, h are Mx l matrixes；

According to the corresponding Ki up precoding vector h of each UE, the feeding back precoding matrix of each UE is determined, wherein, the feeding back precoding matrix is MxKi matrix；

According to the feeding back precoding matrix of each UE, or, according to the feeding back precoding matrix of each UE and other UE feeding back precoding matrix, determine the downlink precoding matrix of each UE.

In second of possible implementation of fifth aspect present invention, the processor specifically for：

Ki up precoding vector 1 ι corresponding to each UE_έIt is normalized, and according to Ki up precoding vectors after each UE normalizeds!^ determines the feeding back precoding matrix of each UE. With reference to the first and second possible implementation of fifth aspect present invention, in the third possible implementation of fifth aspect present invention, the processor specifically for：

The feeding back precoding matrix of each UE is combined, joint feeding back precoding matrix R, R=[QuQ is obtained₂... ^], wherein,（Represent i-th of UE feeding back precoding matrix；

In the 4th kind of possible implementation of fifth aspect present invention, the transmitter is additionally operable to：Notify that each UE sends the feedback reference signal on specified running time-frequency resource position, and the feedback reference signal quantity κ.

In the 5th kind of possible implementation of fifth aspect present invention, the transmitter specifically for：

In the 6th kind of possible implementation of fifth aspect present invention, the transmitter specifically for：

Sixth aspect present invention provides a kind of user equipment (UE), including：

Receiver, the downlink reference signal for receiving base station transmission；

Processor, for carrying out the down channel matrix H that channel estimation obtains down channel according to the downlink reference signal, wherein, the down channel matrix H is NxM matrixes, M is the antenna number that the base station is used, and N is the antenna number that the UE is used, and M and N are positive integer；

K feedback precoding vector is determined according to the down channel matrix H, wherein, K is the quantity for the feedback reference signal that the UE need to be sent, and l≤≤ min (M, N), the feedback precoding vector is Nx l matrixes；

According to described K feedback precoding vector, uplink reference signals are carried out at precoding respectively Reason, obtains κ feedback reference signal；

Transmitter, for sending the κ feedback reference signal to the base station, so that the base station determines the downlink precoding matrix of the UE according to the Κ feedback reference signal.

In the first possible implementation of sixth aspect present invention, the processor specifically for：

Singular value decomposition is carried out to the down channel matrix Η, H is obtained_D = U∑V^H, wherein, U is NxN unitary matrice, and V is Μ χ Μ unitary matrice, and ∑ is Ν χ Μ diagonal matrix；

In second of possible implementation of sixth aspect present invention, the processor specifically for：

By HH^HEigenvalues Decomposition is carried out, H^ HD=U ∑s U is obtained^H, wherein, H^HRepresenting matrix H conjugate matrices, U is NxN unitary matrice, and ∑ is NxM diagonal matrix, U^HFor the conjugate matrices of matrix U；

In the third possible implementation of sixth aspect present invention, the processor specifically for：

With reference to sixth aspect present invention and the 6th aspect the first to the third possible implementation, in the 4th kind of possible implementation of sixth aspect present invention, the processor is additionally operable to：Obtain the quantity K of the running time-frequency resource position for sending the up precoding reference signal and the uplink reference signals.

With reference to sixth aspect present invention and the 6th aspect the first to the 4th kind of possible implementation, in the 5th kind of possible implementation of sixth aspect present invention, the processor specifically for：According to described Κ feedback precoding vector, precoding processing is carried out to uplink reference signals according to below equation： i ⁼ ∑^W(» )(")

M wherein ,/_nRepresent time resource position, k_nFrequency resource position is represented, p represents the antenna serial number of the UE, and β represents amplitude adjusted coefficient, r^(m)Represent that m-th of uplink reference signals uses sequence of complex numbers, r^(m)(n) n-th of plural elements of the sequence of complex numbers, w are represented^(m)Represent the precoding vector that m-th of feedback reference signal is used, l≤m≤K, w^(m)(p) p-th of plural elements of the precoding vector that m-th of uplink reference signals are used are represented.

Determination method, base station and the user equipment of down channel pre-coding matrix provided in an embodiment of the present invention, base station to each UE by sending downlink reference signal, so that each UE carries out channel estimation and obtains down channel matrix H i, and Ki feedback precoding vector is determined according to down channel matrix H i, using reverse precoding vector to returning to Ki feedback reference signal to base station after uplink reference signals precoding, the Ki reference signal that base station is returned according to each UE determines each UE downlink precoding matrix.Because each UE only needs to return to Ki uplink feedback reference signal progress channel estimation, the quantity Ki of uplink feedback reference signal is less than or equal to UE antenna amount, therefore, it is possible to reduce the feedback overhead of uplink reference signals, so as to improve the availability of frequency spectrum.Brief description of the drawings is in order to illustrate more clearly about the embodiment of the present invention or technical scheme of the prior art, the required accompanying drawing used in embodiment or description of the prior art will be briefly described below, apparently, drawings in the following description are some embodiments of the present invention, for those of ordinary skill in the art, without having to pay creative labor, other accompanying drawings can also be obtained according to these accompanying drawings.

Fig. 1 is the flow chart of the determination embodiment of the method one of down channel pre-coding matrix of the present invention；Fig. 2 is the flow chart of the determination embodiment of the method two of down channel pre-coding matrix of the present invention；Fig. 3 is the flow chart of the determination embodiment of the method three of down channel pre-coding matrix of the present invention；Fig. 4 is the flow chart of the determination embodiment of the method four of down channel pre-coding matrix of the present invention；Fig. 5 is a structural representation of base station embodiment of the present invention；

Fig. 6 is two structural representations of base station embodiment of the present invention；

Fig. 7 is the structural representation of user equipment embodiment one of the present invention；

Fig. 8 is the structural representation of user equipment embodiment one of the present invention； Fig. 9 is the structural representation of base station embodiment three of the present invention；

Figure 10 is the structural representation of user equipment embodiment three of the present invention.Embodiment is to make the purpose, technical scheme and advantage of the embodiment of the present invention clearer, below in conjunction with the accompanying drawing in the embodiment of the present invention, technical scheme in the embodiment of the present invention is clearly and completely described, obviously, described embodiment is a part of embodiment of the invention, rather than whole embodiments.Based on the embodiment in the present invention, the every other embodiment that those of ordinary skill in the art are obtained under the premise of creative work is not made belongs to the scope of protection of the invention.

Fig. 1 is the flow chart of the determination embodiment of the method one of down channel pre-coding matrix of the present invention, as shown in figure 1, the method for the present embodiment can include：

Step 101, base station send downlink reference signal to each user equipment (UE).

In this step, each UE of the base station into serving cell sends downlink reference signal, and to support UE to carry out channel estimation, base station and each UE are using many antennas.Downlink reference signal can be public reference signal, or channel condition information detection reference signal (Channel State Information Reference Signal, abbreviation CSI-RS), or the combination of other downlink reference signals or above-mentioned a variety of downlink reference signals.Preferably, downlink reference signal uses CSI-RS, and because the CSI-RS all UE being available in cell are received simultaneously, its expense is smaller.

UE of the base station into serving cell sends downlink reference signal, so that each UE carries out down channel matrix (i=l that channel estimation obtains down channel according to downlink reference signal, 2 ... I), I is the quantity of UE in cell, and Ki feedback precoding vector is determined according to down channel matrix H i, wherein, down channel matrix H i is NiXM matrixes, M is the antenna number that base station is used, Ni is the antenna number that i-th UE is used, M and Ni is positive integer, Ki is the quantity for the feedback reference signal that i-th of UE need to be sent, 1≤≤ (Μ, Λ ^, feeding back precoding vector is_{NiX l}Matrix.For each UE, the UE carries out the down channel matrix H that channel estimation obtains down channel according to the downlink reference signal received, then Ki feedback precoding vector is determined according to down channel matrix H, Ki represents the quantity for the feedback reference signal that k-th UE need to be returned, the quantity K possibility for the feedback reference signal that different UE are returned is identical may also be different, such as premium terminals in cell are equipped with 8 antennas, some low-level terminals only have 1 antenna, it is clear that the quantity of the former feedback reference signal should be more.How UE determines that down channel matrix H is prior art according to downlink reference signal, and UE can root Down channel matrix H is determined according to any one method of the prior art, the present embodiment is not limited this.UE is it is determined that before K feedback precoding vector, in addition it is also necessary to obtain the quantity K for the feedback reference signal that UE need to be sent, each feedback precoding vector one uplink reference signals of correspondence.

Step 102, base station receive the Ki feedback reference signal that each UE is sent, wherein, each UE feedback reference signal is that UE is obtained according to corresponding feedback precoding vector to uplink reference signals progress precoding processing.

Each UE determines Ki feedback precoding vector according to downlink reference signal, and carries out precoding processing to uplink reference signals according to feedback precoding vector, obtains Ki feedback reference signal, each UE Ki uplink reference signals are mutually orthogonal.

Step 103, base station according to each UE feedback reference signal, or, base station is according to each UE feedback reference signal and other UE feedback reference signal, it is determined that each UE downlink precoding matrix.

Base station receives the feedback reference signal that each UE is sent, for each UE, base station carries out up equivalent channel estimation according to the Ki feedback reference signal of the UE, determine the downlink precoding matrix of the UE, or base station carries out up equivalent channel estimation according to the Ki feedback reference signal of the UE and other UE feedback reference signal, determines the up pre- matrix of the UE.In the present embodiment, each UE only needs to return to Ki uplink feedback reference signal progress channel estimation, the quantity Ki of the feedback reference channel of transmission is equal to the transmission number of plies, the maximum transmitted number of plies that system can be supported is determined by down channel rank of matrix, and the order of down channel matrix H depends on the number and the correlation of channel of the dual-mode antenna of channel, the order maximum of down channel matrix H is not more than the minimum value of base station number and antenna amount, thus quantity ^ ^ ^¹¹^^⁷^).In the prior art, the quantity for the uplink reference signals that each UE is sent is equal to UE antenna amount, therefore with the increase of UE antenna amounts, uplink feedback expense can also increase, and in the present embodiment, the quantity of uplink feedback reference signal is unrelated with UE antenna amount, feedback overhead will not with the increase of UE antenna amounts rapid growth, therefore, compared to the prior art, the method that the present embodiment is provided can reduce the expense of uplink reference signals, improve the availability of frequency spectrum.

Referred to herein as equivalent channel estimation, it is because the feedback reference signal that UE is sent is signals of the UE according to feedback precoding vector after precoding, so the result for the uplink channel estimation estimated according to feedback reference signal, corresponding is not to eat dishes without rice or wine channel in itself, but the product of eat dishes without rice or wine channel and feedback precoding vector.In a tdd system, due to the symmetry of up-downgoing channel, base station is according to upper The result that row feedback reference signal is estimated, can as down channel estimated result, so that it is determined that going out down channel matrix.Base station carries out precoding processing, and the data after precoding are sent into UE using downlink precoding matrix after each UE downlink precoding matrix is estimated to downstream signal.

The method that the present embodiment is provided, base station to each UE by sending downlink reference signal, so that each UE carries out channel estimation and obtains down channel matrix H i, and Ki feedback precoding vector is determined according to down channel matrix H i, using reverse precoding vector to returning to Ki feedback reference signal to base station after uplink reference signals precoding, the Ki reference signal that base station is returned according to each UE determines each UE downlink precoding matrix.Because each UE only needs to return to Ki uplink feedback reference signal progress channel estimation, the quantity Ki of uplink feedback reference signal is less than or equal to UE antenna amount, therefore, it is possible to reduce the feedback overhead of uplink reference signals, so as to improve the availability of frequency spectrum.

Several specific embodiments are used below, and the technical scheme to embodiment of the method shown in Fig. 1 is described in detail.

Fig. 2 is the flow chart of the determination embodiment of the method two of down channel pre-coding matrix of the present invention, as shown in Fig. 2 the method for the present embodiment can include：

Step 201, base station notify that each UE sends feedback reference signal on specified running time-frequency resource position, and feedback reference signal quantity Ki.

Base station notifies each UE to send the feedback reference signal of specified quantity on specified running time-frequency resource position.The quantity Ki of feedback reference signal is determined by base station, the quantity Ki for the notice UE feedback reference signals that base station can be shown by signaling, message is indicated as base station sends reference signal to each UE, reference signal indicate message in comprising UE send feedback reference signal running time-frequency resource position, and feedback reference signal quantity Ki.Base station can also notify the quantity Ki of UE feedback reference signals by implicit mode, the total running time-frequency resource taken such as base station to each UE feedback reference signals for sending UE, and the running time-frequency resource of the occupancy of UE each feedback reference signal, so that total running time-frequency resource and the running time-frequency resource of the occupancy of each feedback reference signal that each UE takes according to feedback reference signal determine the quantity Ki of feedback reference signal.Assuming that the size for total running time-frequency resource that feedback reference signal takes is S, the running time-frequency resource size of the occupancy of each feedback reference signal of the UE is L, then feedback reference signal quantity K=S/K.Base station explicitly notifies that UE another implementation method is, UE is informed in base station indirectly by signaling by the number of plies is fed back, and appoints that the quantity Ki of feedback reference signal is equal to the feedback number of plies in advance with UE.

Step 202, base station send downlink reference signal to each UE. Base station sends downlink reference signal to each UE, so that each UE carries out the down channel matrix H that channel estimation obtains down channel according to downlink reference signal, and Ki feedback precoding vector is determined according to down channel matrix H, wherein, down channel matrix H is Ν ^ Μ matrixes, M is the antenna number that base station is used, Ni is the antenna number that i-th of UE is used, M and Ni is positive integer, Ki is the quantity for the feedback reference signal that i-th UE need to be sent, (Μ, Λ ^, feedback precoding vector are matrix to 1≤≤ π ι.

Step 203, base station receive the Ki feedback reference signal that each UE is sent, wherein, each UE feedback reference signal is that UE is obtained according to corresponding feedback precoding vector to uplink reference signals progress precoding processing.

Base station receives the Ki feedback reference signal that each UE is sent, feedback reference signal is corresponded with feedback precoding vector, UE is respectively adopted Ki feedback precoding vector and carries out precoding processing to uplink reference signals, Ki feedback reference signal is obtained, Ki feedback reference signal is sent to base station on specified running time-frequency resource position.For different UE, the quantity Ki possibility of feedback reference signal is identical may also be different.

Step 204, base station carry out equivalent channel estimation respectively according to each UE Ki feedback reference signal, determine the corresponding Ki up precoding vector h of each UE.

Each UE returns to Ki uplink feedback reference signal to base station, for i-th of UE, base station carries out up equivalent channel estimation according to Ki feedback reference signal, is not limited for the method that equivalent channel is estimated, can be using any one method in the prior art.Because the UE uplink feedback reference signals sent have passed through precoding processing, the result of uplink channel estimation, corresponding is not to eat dishes without rice or wine channel in itself, but the product of eat dishes without rice or wine channel and precoding, so using equivalent channel estimation in this step.

For each UE, base station carries out equivalent channel estimation according to Ki feedback reference signal, estimated result is h up precoding vector h, wherein, h is i-th of UE k-th of up precoding vector, k=l, 2 ... Ki, h is Mx l matrixes, and one up precoding vector of each feedback reference signal correspondence is the matrix that up precoding vector ^ arranges for a M row 1.

Each UE feeding back precoding matrix is determined in step 205, base station according to the corresponding Ki up precoding vector h of each UE.

Specifically, Ki corresponding to each UE up precoding vector h are normalized respectively for base station, and determine according to Ki up precoding vector h after each UE normalizeds each UE feeding back precoding matrix.A kind of normalization processing method is simply introduced below, it is assumed that i-th of UE K-th of up precoding vector of feedback is the Ki of h, k=l, 2 ..., then the up precoding vector after normalized ,=ι | | ι rivers, wherein | | h rivers are！^ norm.Certainly there is the method for other normalizeds, the present embodiment is limited not to this.Base station is by the up precoding vector groups of Ki after i-th of UE normalized and gets up, obtain the feeding back precoding matrix Q of UE feedbacks, wherein, feeding back precoding matrix Q is MxKi matrix, each h after normalized as feeding back precoding matrix Q a row.

Step 206, base station according to each UE feeding back precoding matrix, or, base station determines each UE downlink precoding matrix according to each UE feeding back precoding matrix and other UE feeding back precoding matrix.

Base station is according to each UE feeding back precoding matrix, it is determined that each UE downlink precoding matrix is specially, base station directly using the feeding back precoding matrix Q of the UE as the UE downlink precoding matrix, or, base station takes several row in Q matrixes as downlink precoding matrix.

Base station is according to each UE feeding back precoding matrix and other UE feeding back precoding matrix, it is determined that each UE downlink precoding matrix is specially, base station combines each UE feeding back precoding matrix, obtains joint feeding back precoding matrix R Wherein,（I-th of UE feeding back precoding matrix is represented, i=l, 2 ... I, I represents the number of UE in cell.Then, base station determines each UE downlink precoding matrix P according to below equation: P = ( R R^H) R^hR conjugate matrices are represented,（X) represent to matrix X finding the inverse matrix computings.In this implementation, base station it is determined that one of UE downlink precoding matrix when, it is also contemplated that other UE resource information scheduling in cell, so as to eliminate the interference between each UE, more preferable lifting system performance.

Step 207, base station use the corresponding downlink precoding matrixes of each UE, and downlink data is sent to UE.

The method that the present embodiment is provided, base station is in each determination UE downlink precoding matrix, each UE only needs to send Ki uplink feedback reference signal to base station, base station determines each UE feeding back precoding matrix according to each UE feedback reference signal, and each UE downlink precoding matrix is then determined according to each UE feeding back precoding matrix.Base station it is determined that UE downlink precoding matrix when, UE only needs to return to Ki uplink feedback reference signal, compared to the prior art, the quantity of feedback reference signal is less than or equal to UE antenna amount, so as to reduce the feedback overhead of uplink reference signals, frequency efficiency is improved. Fig. 3 is the flow chart of the determination embodiment of the method three of down channel pre-coding matrix of the present invention, as shown in figure 3, the method for the present embodiment can include：

Step 301, UE receive the downlink reference signal that base station is sent, and the down channel matrix H that channel estimation obtains down channel is carried out according to downlink reference signal.

UE carries out channel estimation according to downlink reference signal can use any one existing method of estimation, here it is not limited, the down channel matrix H that UE is estimated is NxM matrixes, M is the antenna number that base station is used, N is the antenna number that UE is used, and M and N are positive integer.

Step 302, UE are according to down channel matrix H_DL determines K feedback precoding vector, wherein, K is the quantity for the feedback reference signal that UE need to be sent, and l≤≤ min (M, N), feedback precoding vector is Nx l matrixes.

UE can determine to feed back precoding vector by following three kinds of modes：

First way：UE carries out singular value decomposition to down channel matrix H（Singular Value Decomposition, abbreviation SVD), obtain H=U ∑s V^H, wherein, U is NxN unitary matrice, and V is Μ χ Μ unitary matrice, and ∑ is Ν χ Μ diagonal matrix.The Κ of matrix U is taken to arrange as Κ feedback precoding vector, or, take the Κ of matrix U to arrange and carry out linear combination, obtain Κ feedback precoding vector.For latter approach, if any row of matrix 11 are expressed as ^₁),>^₂) ..., w_(Q), then linear combination can be expressed as) and=c) (l) w_w+c )(2)_W(₂)+...+c )(Q)w_ra, wherein c^(m)For m-th of feedback precoding vector w^(mUsed linear combination coefficient, it is the complex vector that a length is Q.

The second way：UE is by HH^HEigenvalues Decomposition is carried out, H is obtained_DLH_DL^H = U∑U^h, wherein, H^HRepresenting matrix H conjugate matrices, U is NxN unitary matrice, and ∑ is NxM diagonal matrix, U^HFor the conjugate matrices of matrix U, the K of matrix U is taken to arrange as K feedback precoding vector, or, take the K of matrix U to arrange and carry out linear combination, obtain K feedback precoding vector.

The third mode：UE determines K rear coding vectors of down channel matrix H according to down channel H, precoding vector is fed back using the transposition of coding vector after the K of down channel matrix H as K of down channel matrix H, or the K row progress linear combinations of the transposition of the rear coding vector of row channel matrix H are removed, obtain K feedback precoding vector.

Any one method of the prior art can be used by determining the rear coding vector of down channel, for example, it is assumed that the transmission signal of base station is s, UE reception signal r=H_DReception antenna weighting matrix used in L S+n, its MIMO detections is that (B is the function of down channel matrix H to B）, that is, add Reception signal after power is B*r, weighting matrix is then taken to take B K rows as the rear coding vector of down channel matrix H, then, the transposition of rear coding vector is sought, the transposition of the rear coding vector of down channel matrix H is K feedback precoding vector of down channel matrix H.Determine that the rear coding vector of down channel matrix H also has other methods, do not enumerate here.

Step 303, UE carry out precoding processing to uplink reference signals respectively, obtain K feedback reference signal according to K feedback precoding vector.

UE is determined after K precoding vector, and precoding processing is carried out to uplink reference signals according to precoding vector, obtains K feedback precoded signal, and feedback precoded signal and feedback precoding vector are corresponded.

Step 304, UE send K feedback reference signal to base station, so that base station determines UE downlink precoding matrix according to K feedback reference signal.

UE is after K feedback reference signal is generated, on specified running time-frequency resource position K feedback reference signal is sent to base station, the feedback reference signal is the uplink reference signals after precoding, the K precoded signal that base station is sent according to UE carries out channel estimation, determines UE downlink precoding matrix.

The method that the present embodiment is provided, UE is according to the down channel matrix estimated, determine K precoding vector, precoding processing is carried out to uplink reference signals by K precoding vector, obtain K feedback reference signal, and K feedback reference signal is sent to base station, so that base station carries out channel estimation according to K feedback reference signal, determine downlink precoding matrix.The method that the present embodiment is provided, UE is needed to K uplink feedback reference signal of base station feedback, and the number of feedback reference signal is less than UE antenna amount, so as to reduce the feedback overhead of uplink reference signals.

On the basis of above-described embodiment three, before step 302, that is UE determines before K feedback precoding vector that UE also needs to obtain the quantity K of the running time-frequency resource position for sending up precoding reference signal and uplink reference signals according to down channel matrix H.The quantity K of UE acquisition uplink reference signals can refer to the description in embodiment one, repeat no more here.

In an ofdm system, UE carries out precoding processing to uplink reference signals respectively, obtains K feedback reference signal, feedback reference signal can be expressed as according to K feedback precoding vector： m

Wherein ,/_nRepresent time resource position, k_nFrequency resource position is represented, p represents UE antenna serial number, and β represents amplitude adjusted coefficient, r^(m)Represent that m-th of uplink reference signals uses plural sequence Row, r^(m)(n) n-th of plural elements of sequence of complex numbers, w are represented^(m)Represent the precoding vector that m-th of feedback reference signal is used, l≤≤, w^(m)(p) p-th of plural elements of the precoding vector that m-th of uplink reference signals is used are represented.

Intensive pilot tone is needed to realize that the accurate measurement to frequency-selective channel is different it should be noted that measuring SRS used from up channel, the feedback reference signal for feeding back precoding information can be using relatively sparse pilot tone.For example, as shown in table 1, under 15kHz subcarrier spacing, typical SRS pilot interval is 2 subcarriers, and the pilot interval of a feedback reference signal can be 12 subcarriers, therefore in an OFDM symbol, it is possible to achieve 12 FBRS orthogonal multiplex.In addition, in an OFDM symbol, feedback reference signal can also realize orthogonal multiplex between SRS, so as to support more flexible UL scheduling of resource.As shown in table 2, a SRS takes half subcarrier（Numbering 0), and second half subcarrier（6), then numbering 1 can be scheduled to 6 feedback reference signals and use.The method of the present invention, in identical resource, can send more feedback reference signals, therefore, the quantity of the feedback reference signal sent within the unit interval is substantially reduced, so as to can also reduce uplink feedback expense.

Table 1

Table 2

For below will be by a specific example, it is assumed that have 10 UE in cell, base station and each

UE respectively has 32 antennas, it is necessary to feed back 4 layers of DL precoding informations.If using method of the prior art, feedback reference signal overhead is increased rapidly with UE antenna amounts.It is assumed to be and meets downlink precoding performance, in an OFDM symbol, can only be at most multiplexed 8 SRS (including channeling and cyclic shift）, then in a feedback cycle, required uplink feedback reference signal expense is 10 x 32/8=40 (sym), i.e., 40 OFDM symbols.TDD up-downgoings proportioning is 1:When 1, for 10ms feedback cycle, sub-frame of uplink one has 56 OFDM symbols, therefore only SRS is accomplished by occupying over 70% ascending resource, and this is unacceptable.

Another common downlink precoding method is the precoding technique based on code book in the prior art, Pre-coding matrix quantity in precoding technique based on code book in code book with antenna for base station quantity rather than will be linearly increased.It is assumed to be and meets downlink precoding performance, each UE needs to carry out the pre-coding matrix that 4 rows 32 are arranged accurate quantization feedback, 32 bit quantizations such as are used to each plural number in matrix, its expense would be possible to the ascending resource more than 100%, and this is not achievable.

And if using technical solution of the present invention, then reference signal expense will not both have been increased rapidly with antenna for base station quantity, will not also be increased rapidly with UE antenna amounts.It is assumed to be and meets downlink precoding performance, the pilot interval of feedback reference signal is 12 subcarriers, 12 FBRS can be multiplexed in an OFDM symbol, then in a feedback cycle, required uplink reference signals expense is 10 χ 41 12< 3.5 sym.For 10ms feedback cycle, feedback reference signal only needs to take 6% ascending resource.

Fig. 4 is the flow chart of the determination embodiment of the method four of down channel pre-coding matrix of the present invention, as shown in figure 4, the method for the present embodiment can include：

Step 401, base station notify that each UE sends feedback reference signal on specified running time-frequency resource position, and feedback reference signal quantity Ki.

Embodiment can refer to the description of embodiment two, repeat no more here.

Step 402, base station send downlink reference signal to each UE.

Base station sends downlink reference signal to each UE, so that each UE carries out the down channel matrix that channel estimation obtains down channel according to downlink reference signal.

Step 403, each UE receive the downlink reference signal that base station is sent, and the down channel matrix that channel estimation obtains down channel is carried out according to downlink reference signal.

Wherein, down channel matrix is NiXM matrixes, and M is the antenna number that base station is used, and Ni is the antenna number that i-th of UE is used, and M and Ni are positive integer.

Step 404, each UE determine Ki feedback precoding vector according to down channel matrix H i.

Hi is the quantity for the feedback reference signal that i-th of UE need to be sent, and (Μ, Λ ^, feedback precoding vector are NiX l matrixes to 1≤≤ π ι.UE determines that the specific method for feeding back precoding vector can refer to the description of embodiment three according to down channel road matrix, repeats no more here.

Step 405, each UE carry out precoding processing to uplink reference signals respectively according to Ki feedback precoding vector, obtain K feedback reference signal, and send feedback reference signal to base station on specified running time-frequency resource position.

There are strict requirements different peak-to-average force ratio from the measuring SRS of up channel, requirement of the feedback reference signal to peak-to-average force ratio can be relatively loose, therefore be not necessarily required to use ZC sequence next life Into the pilot signal of feedback reference signal.For example, both sides can arrange, according to the signaling of base station, using defined parameter, based on certain specific pseudo-random sequence, the pilot signal on running time-frequency resource is specified in generation.Assuming that m-th of feedback reference signal that UE is sent, sends on specified N number of RE, wherein the time-domain OFDM symbol serial number corresponding to n-th of RE/_n, corresponding subcarrier in frequency domain serial number k_n, then the particular feedback reference signal that UE is sent on antenna p can be expressed as：

Wherein ,/_ηRepresent time resource position, k_nShow frequency m

Resource location, p represents UE antenna serial number, and β represents amplitude adjusted coefficient, r^(m)Represent that m-th of uplink reference signals uses sequence of complex numbers, r^(m)(n) n-th of plural elements of sequence of complex numbers, w are represented^(m)Represent the precoding vector that m-th of feedback reference signal is used, l≤m≤K, w^(m)(p) p-th of plural elements of the precoding vector that m-th of uplink reference signals is used are represented.

In addition, UE can send uplink feedback reference signal using relatively sparse pilot tone, the utilization rate of pilot tone can be provided, in identical resource, more feedback reference signals can be sent, therefore, the quantity of the feedback reference signal sent within the unit interval is substantially reduced, so as to can also reduce uplink feedback expense.

Step 406, base station receive the Ki feedback reference signal that each UE is sent, according to each UE's

Ki feedback reference signal carries out equivalent channel estimation respectively, determines the corresponding Ki up precoding vector h of each UE.

Base station receives the Ki feedback reference signal that each UE is sent, feedback reference signal is corresponded with feedback precoding vector, for i-th of UE, precoding processing is carried out to uplink reference signals using Ki feedback precoding vector, Ki feedback reference signal is obtained, and the Ki feedback reference signal is sent to base station on specified running time-frequency resource position.

For i-th of UE, base station carries out equivalent channel estimation according to Ki feedback reference signal, and estimated result is Ki up precoding vector h_Lk, one up precoding vector h of each feedback reference signal correspondence, wherein, up precoding vector!^ is Mx l matrixes, i.e., up precoding vector is the matrix that a M row 1 is arranged.

Each UE feeding back precoding matrix is determined in step 407, base station according to the corresponding Ki up precoding vector h of each UE, wherein, feeding back precoding matrix is MxKi matrix.

Specifically, Ki corresponding to each UE up precoding vectors are normalized respectively for base station, and each UE feeding back precoding matrix Qi is determined according to Ki up precoding vectors after each UE normalizeds, wherein, feeding back precoding matrix Qi is MxKi matrix, is returned One change processing after each h as feeding back precoding matrix Qi a row.

Step 408, base station according to each UE feeding back precoding matrix, or, base station is according to each UE feeding back precoding matrix and other UE feeding back precoding matrix, it is determined that each UE downlink precoding matrix.

Base station is according to each UE feeding back precoding matrix Qi, the downlink precoding matrix for determining each UE is specially, base station directly using feeding back precoding matrix Qi as i-th of UE downlink precoding matrix P, or, base station takes several row in Qi matrixes as downlink precoding matrix P.

Base station determines each UE downlink precoding matrix specifically, base station combines each UE feeding back precoding matrix, obtains joint feeding back precoding matrix R according to each UE feeding back precoding matrix Qi and other UE feeding back precoding matrix, Wherein,（I-th of UE feeding back precoding matrix is represented, i=l, 2 ... I, I represents the number of UE in cell.Then, base station determines each UE downlink precoding matrix P according to below equation: P = ( R R^H) R, R^HR conjugate matrices are represented,（X) represent to matrix X finding the inverse matrix computings.In this implementation, base station it is determined that one of UE downlink precoding matrix when, it is also contemplated that other UE resource information scheduling in cell, so as to eliminate the interference between each UE, more preferable lifting system performance.

Step 409, base station use the corresponding downlink precoding matrixes of each UE, and downlink data is sent to UE.

The method that the present embodiment is provided, base station it is determined that each UE downlink precoding matrix when, each UE only needs to send Ki uplink feedback reference signal to base station, base station determines each UE feeding back precoding matrix according to each UE feedback reference signal, and each UE downlink precoding matrix is then determined according to each UE feeding back precoding matrix.Base station it is determined that UE downlink precoding matrix when, each UE only needs to return to Ki uplink feedback reference signal, the quantity of feedback reference signal is less than or equal to UE antenna amount, so as to reduce the feedback overhead of uplink reference signals, improves frequency efficiency.

In the present embodiment, it is related to two kinds of reference signals：Downlink reference signal, uplink feedback reference signal.Wherein, the downlink reference signal sent by base station, such as CSI-RS, because be available for a large amount of UE in cell to receive simultaneously, its expense is smaller；The uplink feedback reference signal sent by UE, it is both unrelated with antenna for base station quantity because its quantity is equal to the transmission number of plies, it is also unrelated with UE antenna amounts, so its expense also very little.Therefore, when antenna amount increases, feedback reference signal overhead needed for technical solution of the present invention will not be with antenna amount rapid growth, compared with prior art, it is possible to achieve relatively low expense.

Fig. 5 is a structural representation of base station embodiment of the present invention, as shown in figure 5, the present embodiment is carried The base station of confession includes：Sending module 51, receiving module 52, pre-coding matrix determining module 53.Wherein, sending module 51, for sending downlink reference signal to each user equipment (UE), so that each UE carries out down channel matrix H i (i=l that channel estimation obtains down channel according to downlink reference signal, 2 ... I), I is the quantity of UE in cell, and Ki feedback precoding vector is determined according to down channel matrix H i, wherein, down channel matrix H i is Ν ^ Μ matrixes, M is the antenna number that base station is used, Ni is the antenna number that i-th of UE is used, M and Ni is positive integer, Ki is the quantity for the feedback reference signal that i-th UE need to be sent, 1≤≤ π ι (Μ, Λ ^, feedback precoding vector is matrix；

Receiving module 52, for receiving the Ki feedback reference signal that each UE is sent, wherein, each UE feedback reference signal is that UE is obtained according to corresponding feedback precoding vector to uplink reference signals progress precoding processing；

Pre-coding matrix determining module 53, for the feedback reference signal according to each UE, or, according to the up precoding reference signal of each each UE feedback reference signal and other UE, determine each UE downlink precoding matrix.

The base station that the present embodiment is provided can be used for performing the method shown in embodiment one, and specific implementation is similar with technique effect, repeats no more here, can refer to the description of embodiment one.

Fig. 6 is the structural representation of base station embodiment two of the present invention, as shown in fig. 6, the base station that the present embodiment is provided includes：Sending module 61, receiving module 62, pre-coding matrix determining module 63.

Sending module 61, for sending downlink reference signal to each user equipment (UE), so that each UE carries out down channel matrix (i=l that channel estimation obtains down channel according to downlink reference signal, 2 ... I), I is the quantity of UE in cell, and Ki feedback precoding vector is determined according to down channel matrix H i, wherein, down channel matrix H i is Ν ^ Μ matrixes, M is the antenna number that base station is used, Ni is the antenna number that i-th of UE is used, M and Ni is positive integer, Ki is the quantity for the feedback reference signal that i-th of UE need to be sent, 1≤≤ (Μ, Λ ^, feeding back precoding vector is_{NiX l}Matrix；

Receiving module 62, for receiving the Ki feedback reference signal that each UE is sent, wherein, each UE feedback reference signal is that UE is obtained according to corresponding feedback precoding vector to uplink reference signals progress precoding processing；

Pre-coding matrix determining module 63, for the feedback reference signal according to each UE, or, according to the up precoding reference signal of each each UE feedback reference signal and other UE, it is determined that Each UE downlink precoding matrix.

In the present embodiment, pre-coding matrix determining module 63 includes：Up precoding vector determining unit 631, feeding back precoding matrix determining unit 632 and downlink precoding matrix determining unit 633.

Up precoding vector determining unit 631, channel estimation is carried out respectively for the Ki feedback reference signal according to each UE, determine the corresponding Ki up precoding vector h of each UE, wherein, h is i-th of UE k-th of up precoding vector, k=l, 2 ... Ki, h are Μ χ matrixes；

Feeding back precoding matrix determining unit 632, for according to the corresponding Ki up precoding vector ι of each UE_έ, each UE feeding back precoding matrix is determined, wherein, feeding back precoding matrix is MxKi matrix；

Downlink precoding matrix determining unit 633, for the feeding back precoding matrix according to each UE, or, according to each UE feeding back precoding matrix and other UE feeding back precoding matrix, determine each UE downlink precoding matrix.

In a kind of feasible implementation, feeding back precoding matrix determining unit 632 specifically for：Ki corresponding to each UE up precoding vectors!^ is normalized, and determines according to the Ki up precoding vector h after each UE normalizeds each UE feeding back precoding matrix.Downlink precoding matrix determining unit 633 specifically for：Each UE feeding back precoding matrix is combined, joint feeding back precoding matrix R is obtained, Wherein,（Represent i-th of UE feeding back precoding matrix；Each UE downlink precoding matrix P is determined according to below equation: P = ( R R^H) R, R^HR conjugate matrices are represented,（X) represent that to matrix X finding the inverse matrixs fortune further in the present embodiment, sending module 61 is additionally operable to：Notify that each UE sends feedback reference signal on specified running time-frequency resource position, and feedback reference signal quantity K.

Sending module 61 specifically can notify UE by following two modes, to each UE send reference signal indicate message, reference signal indicate message in comprising UE send feedback reference signal running time-frequency resource position, and feedback reference signal quantity K.Or, the total running time-frequency resource taken to each UE feedback reference signals for sending UE, and the running time-frequency resource of the occupancy of UE each feedback reference signal, so that total running time-frequency resource and the running time-frequency resource of the occupancy of each feedback reference signal that each UE takes according to feedback reference signal determine the quantity Κ of feedback reference signal.

The base station that the present embodiment is provided, available for the technology for performing the offer of embodiment of the method one, two, four Scheme, specific implementation is similar with technique effect, repeats no more here, can refer to the description of each method embodiment.

Fig. 7 is the structural representation of user equipment embodiment one of the present invention, as shown in fig. 7, the user equipment that the present embodiment is provided includes：Receiving module 71, down channel matrix deciding module 72, feedback precoding vector determining module 73, precoding processing module 74, sending module 75.

Wherein, receiving module 71, the downlink reference signal for receiving base station transmission；

Down channel matrix deciding module 72, for carrying out the down channel matrix H that channel estimation obtains down channel according to downlink reference signal, wherein, down channel matrix H is Ν χ Μ matrixes, M is the antenna number that base station is used, and N is the antenna number that UE is used, and M and N are positive integer；

Precoding vector determining module 73 is fed back, for determining K feedback precoding vector according to down channel matrix H, wherein, K is the quantity for the feedback reference signal that UE need to be sent,

l≤^≤min( , N) ₎Feedback precoding vector is Nxl matrixes；

Precoding processing module 74, for according to K feedback precoding vector, carrying out precoding processing to uplink reference signals respectively, obtaining K feedback reference signal；

Sending module 75, for sending K feedback reference signal to base station, so that base station determines UE downlink precoding matrix according to K feedback reference signal.

The user equipment that the present embodiment is provided, available for the technical scheme that embodiment of the method three is provided is performed, specific implementation is similar with technique effect, repeats no more here, can refer to the description of embodiment three.

Fig. 8 is the structural representation of user equipment embodiment one of the present invention, as shown in figure 8, the user equipment that the present embodiment is provided includes：Receiving module 81, down channel matrix deciding module 82, feedback precoding vector determining module 83, precoding processing module 84, sending module 85.

Receiving module 81, the downlink reference signal for receiving base station transmission；

Down channel matrix deciding module 82, for carrying out the down channel matrix H that channel estimation obtains down channel according to downlink reference signal, wherein, down channel matrix H is NxM matrixes, M is the antenna number that base station is used, and N is the antenna number that UE is used, and M and N are positive integer；

Precoding vector determining module 83 is fed back, for determining K feedback precoding vector according to down channel matrix H, wherein, K is the quantity for the feedback reference signal that UE need to be sent,

l≤^≤min( , N) ₎Feedback precoding vector is Nxl matrixes；

Precoding processing module 84, for according to K feedback precoding vector, respectively to up ginseng Examine signal and carry out precoding processing, obtain κ feedback reference signal；

Sending module 85, for sending K feedback reference signal to base station, so that base station determines UE downlink precoding matrix according to K feedback reference signal.

In the first feasible implementation, feedback precoding vector determining module 83 specifically for：Singular value decomposition is carried out to down channel matrix H, H=U ∑s V is obtained^H, wherein, U is NxN unitary matrice, and V is Μ χ Μ unitary matrice, and ∑ is Ν χ Μ diagonal matrix；The Κ of matrix U is taken to arrange as Κ feedback precoding vector, or, take any Κ of matrix U to arrange and carry out linear combination, obtain Κ feedback precoding vector.

In second of feasible implementation, feedback precoding vector determining module 83 specifically for：By Η Η^ΗEigenvalues Decomposition is carried out, H^ HD Z UZUH are obtained, wherein, H^HRepresenting matrix H conjugate matrices, U is NxN unitary matrice, and ∑ is Ν χ Μ diagonal matrix, U^HFor the conjugate matrices of matrix U；The K of matrix U is taken to arrange as K feedback precoding vector, or, take any K of matrix U to arrange and carry out linear combination, obtain K feedback precoding vector.

In the third feasible implementation, feedback precoding vector determining module 83 specifically for：Coding vector after K of down channel H is determined according to down channel H；Precoding vector is fed back using the transposition of coding vector after down channel H K as K of H, or takes any K row of the transposition of coding vector after K of down channel H to carry out linear combination, K feedback precoding vector is obtained.

Further, the user equipment that this implementation is provided also includes：Acquisition module 86, the running time-frequency resource position of up precoding reference signal and the quantity K of uplink reference signals are sent for obtaining.

In the present embodiment, precoding processing module 84 specifically for：According to Κ feedback precoding vector, formula carries out precoding processing to uplink reference signals：

M wherein ,/_nRepresent time resource position, k_nFrequency resource position is represented, p represents UE antenna serial number, and β represents amplitude adjusted coefficient, r^(m)Represent that m-th of uplink reference signals uses sequence of complex numbers, r^(m)(n) n-th of plural elements of sequence of complex numbers, w are represented^(m)Represent the precoding vector that m-th of feedback reference signal is used, l≤m≤f, w^(m)(p) p-th of plural elements of the precoding vector that m-th of uplink reference signals is used are represented.

The user equipment that the present embodiment is provided, is provided available for execution embodiment of the method three and example IV Technical scheme, specific implementation is similar with technique effect, repeats no more here, can refer to the description of embodiment three and example IV.

Fig. 9 is the structural representation of base station embodiment three of the present invention, as shown in figure 9, the base station 900 that the present embodiment is provided includes：Processor 91, memory 92, transmitter 93, receiver 94.Memory 92, transmitter 93 are connected with receiver 94 by bus with processor 91.Wherein, the storage of memory 92 execute instruction, when base station is run, communicates between processor 91 and memory 92, and processor 91 performs execute instruction and causes base station to perform the determination method for the down channel pre-coding matrix that the present invention is provided.

Wherein, transmitter 93, for sending downlink reference signal to each user equipment (UE), so that each UE carries out the down channel matrix that channel estimation obtains down channel according to downlink reference signal_Hi(i=l, 2 ... I), I is the quantity of UE in cell, and Ki feedback precoding vector is determined according to down channel matrix H i, wherein, down channel matrix H i is NiXM matrixes, and M is the antenna number that base station is used, Ni is the antenna number that i-th of UE is used, M and Ni is positive integer, and Ki is the quantity for the feedback reference signal that i-th of UE need to be sent, 1≤≤ (Μ, Λ ^, feeding back precoding vector is_{NiX l}Matrix；

Receiver 94, for receiving the Ki feedback reference signal that each UE is sent, wherein, each

UE feedback reference signal is that UE is obtained according to corresponding feedback precoding vector to uplink reference signals progress precoding processing；

Processor 91, for the feedback reference signal according to each UE, or, according to the up precoding reference signal of each each UE feedback reference signal and other UE, determine each UE downlink precoding matrix.

Processor 91 specifically for：Channel estimation is carried out according to each UE Ki feedback reference signal respectively, the corresponding Ki up precoding vector h of each UE is determined, wherein, h is i-th of UE k-th of up precoding vector, k=l, 2 ... Ki, h are Mx l matrixes；According to the corresponding Ki up precoding vector h of each UE, each UE feeding back precoding matrix is determined, wherein, feeding back precoding matrix is MxKi matrix；According to each UE feeding back precoding matrix, or, according to each UE feeding back precoding matrix and other UE feeding back precoding matrix, determine each UE downlink precoding matrix.

Processor 91 according to following methods specifically for obtaining the corresponding Ki up precoding vector of each UE：

Ki corresponding to each UE up precoding vectors！^ is normalized, and according to each Ki up precoding vector h after UE normalizeds determine each UE feeding back precoding matrix.In a kind of possible implementation, processor 91 specifically for determining each UE downlink precoding matrix in the following manner：

Each UE feeding back precoding matrix is combined, obtain joint feeding back precoding matrix R, R=[QU, wherein, represent i-th of UE feeding back precoding matrix；

Each UE downlink precoding matrix P is determined according to below equation:

In the present embodiment, transmitter 93 is additionally operable to：Notify that each UE sends feedback reference signal on specified running time-frequency resource position, and feedback reference signal quantity K.Transmitter 93 specifically for：To each UE send reference signal indicate message, reference signal indicate message in comprising UE send feedback reference signal running time-frequency resource position, and feedback reference signal quantity K.Or, total running time-frequency resource that transmitter 93 takes to each UE feedback reference signals for sending UE, and the running time-frequency resource of the occupancy of UE each feedback reference signal, so that total running time-frequency resource and the running time-frequency resource of the occupancy of each feedback reference signal that each UE takes according to feedback reference signal determine the quantity Κ of feedback reference signal：.

The base station that the present embodiment is provided, can be used for the technical scheme for performing above method embodiment, and its implementing principle and technical effect is similar, and here is omitted.

Figure 10 is the structural representation of user equipment embodiment three of the present invention, as shown in Figure 10, and the user equipment 100 that the present embodiment is provided includes：Processor 11, memory 12, transmitter 13 and receiver 14, transmitter 13, receiver 14 and memory 12 can be connected by bus with processor 11.Wherein, memory 11 stores execute instruction, when user equipment 100 is run, communicated between processor 11 and memory 12, processor 11 performs execute instruction and causes user equipment to perform the determination method of the down channel pre-coding matrix of the present embodiment offer.

Wherein, receiver 14, the downlink reference signal for receiving base station transmission；

Processor 11, for carrying out the down channel matrix Η that channel estimation obtains down channel according to downlink reference signal, wherein, down channel matrix Η is NxM matrixes, Μ is the antenna number that base station is used, and Ν is the antenna number that UE is used, and Μ and Ν are positive integer；

Κ feedback precoding vector is determined according to down channel matrix Η, wherein, Κ is the quantity for the feedback reference signal that UE need to be sent, and l≤≤ min (M, N), feedback precoding vector is N><1 square Battle array；

According to K feedback precoding vector, precoding processing is carried out to uplink reference signals respectively, κ feedback reference signal is obtained；

Transmitter 13, for sending Κ feedback reference signal to base station, so that base station determines UE downlink precoding matrix according to Κ feedback reference signal.

Alternatively, processor 11 specifically for：Singular value decomposition is carried out to down channel matrix Η, H=U ∑s V is obtained^H, wherein, U is NxN unitary matrice, and V is MxM unitary matrice, and ∑ is NxM diagonal matrix；The K of matrix U is taken to arrange as K feedback precoding vector, or, take any K of matrix U to arrange and carry out linear combination, obtain K feedback precoding vector.

Alternatively, processor 11 specifically for：By HH^HEigenvalues Decomposition is carried out, is obtained

H_DLH_DL ^H ^ U∑U^H, wherein, H^HRepresenting matrix H conjugate matrices, U is NxN unitary matrice, and ∑ is NxM diagonal matrix, U^HFor the conjugate matrices of matrix U；The K of matrix U is taken to arrange as K feedback precoding vector, or, take any K of matrix U to arrange and carry out linear combination, obtain K feedback precoding vector.

Alternatively, processor 11 specifically for：Coding vector after K of down channel H is determined according to down channel H；Precoding vector is fed back using the transposition of coding vector after down channel H K as K of H, or takes any K row of the transposition of coding vector after K of down channel H to carry out linear combination, K feedback precoding vector is obtained.

In the present embodiment, processor 11 is additionally operable to：Obtain the quantity K of the running time-frequency resource position for sending up precoding reference signal and uplink reference signals.

In a kind of feasible implementation, processor 11 is specifically for according to Κ feedback precoding vector, formula carries out precoding processing to uplink reference signals：

The user equipment that the present embodiment is provided, can be used for the technical scheme for performing above method embodiment, Its implementing principle and technical effect is similar, and here is omitted.

One of ordinary skill in the art will appreciate that：Realizing all or part of step of above-mentioned each method embodiment can be completed by the related hardware of programmed instruction.Foregoing program can be stored in a computer read/write memory medium.The program upon execution, performs the step of including above-mentioned each method embodiment；And foregoing storage medium includes：ROM, RAM, magnetic disc or CD etc. are various can be with the medium of store program codes.Finally it should be noted that：Various embodiments above is merely illustrative of the technical solution of the present invention, rather than its limitations；Although the present invention is described in detail with reference to foregoing embodiments, it will be understood by those within the art that：It can still modify to the technical scheme described in foregoing embodiments, or carry out equivalent substitution to which part or all technical characteristic；And these modifications or replacement, the essence of appropriate technical solution is departed from the scope of various embodiments of the present invention technical scheme.

Claims

Claims

1st, a kind of determination method of down channel pre-coding matrix, it is characterised in that including：Base station sends downlink reference signal to each user equipment (UE), so that each UE carries out down channel matrix H i (i=l that channel estimation obtains down channel according to the downlink reference signal, 2 ... I), I is the quantity of UE in cell, and Ki feedback precoding vector is determined according to the down channel matrix H i, wherein, the down channel matrix H i is matrix, M is the antenna number that the base station is used, Ni is the antenna number that i-th of UE is used, M and Ni is positive integer, Ki is the quantity for the feedback reference signal that i-th UE need to be sent, 1≤≤ π ι (Μ, Λ ^, the feedback precoding vector is matrix；

The base station receives the Ki feedback reference signal that each UE is sent, wherein, it is each described

The UE feedback reference signal is that the UE is obtained according to corresponding feedback precoding vector to uplink reference signals progress precoding processing；

The base station according to the feedback reference signal of each UE, or, the base station determines the downlink precoding matrix of each UE according to each each UE feedback reference signal and other UE up precoding reference signal.

2nd, according to the method described in claim 1, it is characterized in that, the base station is according to the feedback reference signal of each UE, or, the base station is according to the feedback reference signal of each UE and other UE up precoding reference signal, the downlink precoding matrix of each UE is determined, including：

The base station carries out channel estimation respectively according to the Ki feedback reference signal of each UE, determines the corresponding Ki up precoding vector h of each UE, wherein, h is i-th of UE k-th of up precoding vector, k=l, 2 ... Ki, h are Mx l matrixes；

The base station is according to the corresponding Ki up precoding vector h of each UE_Lk, the feeding back precoding matrix of each UE is determined, wherein, the feeding back precoding matrix is MxKi matrix;The base station according to the feeding back precoding matrix of each UE, or, the base station determines the downlink precoding matrix of each UE according to the feeding back precoding matrix of each UE and other UE feeding back precoding matrix.

3rd, method according to claim 2, it is characterised in that the feeding back precoding matrix of each UE is determined in the base station according to the corresponding Ki up precoding vector h of each UE, including： Ki up precoding vector h corresponding to each UE is normalized respectively for the base station, and determines according to Ki up precoding vectors after each UE normalizeds the feeding back precoding matrix of each UE.

4th, the method according to any one of Claims 2 or 3, it is characterised in that the base station determines the downlink precoding matrix of each UE according to the feeding back precoding matrix of each UE and other UE feeding back precoding matrix, including：

The base station combines the feeding back precoding matrix of each UE, obtain joint feeding back precoding matrix R, R=[QU, wherein, represent i-th of UE feeding back precoding matrix;The base station determines the downlink precoding matrix P of each UE according to below equation:

P = ( R R^H) ^A R, R^HR conjugate matrices are represented,（X) represent to matrix X finding the inverse matrix computings.

5th, according to the method described in claim 1, it is characterised in that the base station to each user equipment (UE) send downlink reference signal before, in addition to：

The base station notifies that each UE sends the feedback reference signal on specified running time-frequency resource position, and the feedback reference signal quantity.

6th, method according to claim 5, it is characterised in that the base station notifies that each UE sends the up reference information on specified running time-frequency resource position, and the up reference information quantity K, including：

The base station sends reference signal to each UE and indicates message, and the reference signal indicates to send the running time-frequency resource position of the feedback reference signal in message comprising the UE, and the feedback reference signal quantity.

7th, method according to claim 5, it is characterised in that the base station notifies that each UE sends the feedback reference signal on specified running time-frequency resource position, and the feedback reference signal quantity Κ, including：

Total running time-frequency resource that the base station takes to each UE feedback reference signals for sending the UE, and the running time-frequency resource of the occupancy of each feedback reference signal of the UE, so that total running time-frequency resource and the running time-frequency resource of the occupancy of each feedback reference signal that each UE takes according to the feedback reference signal determine the quantity Κ of the feedback reference signal.

8th, a kind of determination method of down channel pre-coding matrix, it is characterised in that including：User equipment (UE) receives the downlink reference signal that base station is sent, according to the downlink reference signal The down channel matrix H that channel estimation obtains down channel is carried out, wherein, the down channel matrix H is NxM matrixes, and M is the antenna number that the base station is used, and N is the antenna number that the UE is used, and M and N are positive integer；

The UE determines K feedback precoding vector according to the down channel matrix H, wherein, K is the quantity for the feedback reference signal that the UE need to be sent, and l≤≤ min (M, N), the feedback precoding vector is Nx l matrixes；

The UE carries out precoding processing to uplink reference signals respectively, obtains K feedback reference signal according to described K feedback precoding vector；

The UE sends the K feedback reference signal to the base station, so that the base station determines the downlink precoding matrix of the UE according to the K feedback reference signal.

9th, method according to claim 8, it is characterised in that the UE determines K feedback precoding vector according to the down channel matrix H, including：

The UE carries out singular value decomposition to the down channel matrix H, obtains H_D = U∑V^H, wherein, U is Ν χ Ν unitary matrice, and V is Μ χ Μ unitary matrice, and ∑ is NxM diagonal matrix；

The K of matrix U is taken to arrange as described K feedback precoding vector, or, take any K of matrix U to arrange and carry out linear combination, obtain the K feedback precoding vector.

10th, method according to claim 9, it is characterised in that the UE determines K feedback precoding vector according to the down channel matrix H, including：

The UE is by HH^HEigenvalues Decomposition is carried out, is obtained Z USUH, wherein, H^HRepresenting matrix H conjugate matrices, U is NxN unitary matrice, and ∑ is NxM diagonal matrix, U^HFor the conjugate matrices of matrix U；

The K of matrix U is taken to arrange as described K feedback precoding vector, or, take any K of matrix U to arrange and carry out linear combination, obtain the K feedback precoding vector.

11, method according to claim 8, it is characterised in that the UE determines K feedback precoding vector according to the down channel matrix H, including：

The UE determines the K rear coding vectors of the down channel H according to the down channel H；Precoding vector is fed back using the transposition of coding vector after the K of the down channel H as described K of H, or take any K row of the transposition of coding vector after K of down channel H to carry out linear combination, obtain the K feedback precoding vector.

12nd, the method according to any one of claim 8- 11, it is characterised in that the UE roots According to the down channel matrix H determine K feedback precoding vector before, in addition to：The UE obtains the quantity K of the running time-frequency resource position for sending the up precoding reference signal and the uplink reference signals.

13rd, the method according to claim any one of 8-12, it is characterised in that the UE carries out precoding processing to uplink reference signals respectively, obtained according to described Κ feedback precoding vector

Κ feedback reference signal, including：

The UE carries out precoding processing according to below equation according to described Κ feedback precoding vector to uplink reference signals： i⁼ ∑^w(» )(")

m

Wherein ,/_nRepresent time resource position, k_nFrequency resource position is represented, p represents the antenna serial number of the UE, and β represents amplitude adjusted coefficient, r^(m)Represent that m-th of uplink reference signals uses sequence of complex numbers, r^(m)(n) n-th of plural elements of the sequence of complex numbers, w are represented^(m)Represent the precoding vector that m-th of feedback reference signal is used, l≤m≤K, w^(m)(p) p-th of plural elements of the precoding vector that m-th of uplink reference signals are used are represented.

14th, a kind of base station, it is characterised in that including：

Sending module, for sending downlink reference signal to each user equipment (UE), so that each UE carries out the down channel matrix that channel estimation obtains down channel according to the downlink reference signal

(i=l, 2 ... I), I is the quantity of UE in cell, and Ki feedback precoding vector is determined according to the down channel matrix H i, wherein, the down channel matrix H i is matrix, M is the antenna number that the base station is used, Ni is the antenna number that i-th of UE is used, M and Ni is positive integer, and Ki is the quantity for the feedback reference signal that i-th of UE need to be sent, 1≤≤ π ι (Μ, Λ ^, the feedback precoding vector is NiX l matrixes；

Receiving module, for receiving the Ki feedback reference signal that each UE is sent, wherein, each UE feedback reference signal is that the UE is obtained according to corresponding feedback precoding vector to uplink reference signals progress precoding processing；

Pre-coding matrix determining module, for the feedback reference signal according to each UE, or, according to the up precoding reference signal of each each UE feedback reference signal and other UE, determine the downlink precoding matrix of each UE.

15th, base station according to claim 14, it is characterised in that the pre-coding matrix is true Cover half block includes：

Up precoding vector determining unit, channel estimation is carried out respectively for the Ki feedback reference signal according to each UE, determine the corresponding Ki up precoding vector h of each UE, wherein, for i-th of UE k-th of up precoding vector, k=l, 2 ... Ki, h are Μ χ matrixes；

Feeding back precoding matrix determining unit, for according to the corresponding Ki up precoding vector h of each UE, determining the feeding back precoding matrix of each UE, wherein, the feeding back precoding matrix is MxKi matrix；

Downlink precoding matrix determining unit, for the feeding back precoding matrix according to each UE, or, according to the feeding back precoding matrix of each UE and other UE feeding back precoding matrix, determine the downlink precoding matrix of each UE.

16th, base station according to claim 15, it is characterised in that the feeding back precoding matrix determining unit specifically for：

Ki up precoding vector corresponding to each UE is normalized, and according to Ki up precoding vectors after each UE normalizeds!^ determines the feeding back precoding matrix of each UE.

17th, the base station according to any one of claims 14 or 15, it is characterised in that the downlink precoding matrix determining unit specifically for：

The feeding back precoding matrix of each UE is combined, joint feeding back precoding matrix R, R=[Q is obtained_{1 ?}Q₂... Q, wherein, represent i-th of UE feeding back precoding matrix；

The downlink precoding matrix P of each UE is determined according to below equation:

P = ( R R^H) R, R^HR conjugate matrices are represented,（X) represent to matrix X finding the inverse matrix computings.

18th, base station according to claim 14, it is characterised in that the sending module is additionally operable to：

Notify that each UE sends the feedback reference signal on specified running time-frequency resource position, and the feedback reference signal quantity K.

19th, base station according to claim 18, it is characterised in that the sending module specifically for：

Reference signal is sent to each UE and indicates message, and the reference signal indicates to include in message The UE sends the running time-frequency resource position of the feedback reference signal, and the feedback reference signal quantity K.

20th, base station according to claim 18, it is characterised in that the sending module specifically for：

The total running time-frequency resource taken to each UE feedback reference signals for sending the UE, and the running time-frequency resource of the occupancy of each feedback reference signal of the UE, so that total running time-frequency resource and the running time-frequency resource of the occupancy of each feedback reference signal that each UE takes according to the feedback reference signal determine the quantity Κ of the feedback reference signal.

21st, a kind of user equipment (UE), it is characterised in that including：

Receiving module, the downlink reference signal for receiving base station transmission；

Down channel matrix deciding module, for carrying out the down channel matrix H that channel estimation obtains down channel according to the downlink reference signal, wherein, the down channel matrix H is NxM matrixes, M is the antenna number that the base station is used, N is the antenna number that the UE is used, and M and N are positive integer；

Precoding vector determining module is fed back, for determining K feedback precoding vector according to the down channel matrix H, wherein, the quantity for the feedback reference signal that K need to be sent for the UE, l≤^≤min (, N)₎The feedback precoding vector is Nx l matrixes；

Precoding processing module, for according to described K feedback precoding vector, carrying out precoding processing to uplink reference signals respectively, obtaining κ feedback reference signal；

Sending module, for sending the K feedback reference signal to the base station, so that the base station determines the downlink precoding matrix of the UE according to the K feedback reference signal.

22nd, user equipment according to claim 21, it is characterised in that the feedback precoding vector determining module specifically for：

Singular value decomposition is carried out to the down channel matrix H, H is obtained_D = U∑V^H, wherein, U is NxN unitary matrice, and V is MxM unitary matrice, and ∑ is NxM diagonal matrix；

The K of matrix U is taken to arrange as described K feedback precoding vector, or, take any K of matrix U to arrange and carry out linear combination, obtain K feedback precoding vector.

23rd, user equipment according to claim 21, it is characterised in that the feedback precoding vector determining module specifically for：

By HH^HEigenvalues Decomposition is carried out, H is obtained_nt H_nt H = U∑U^H, wherein, H^HRepresenting matrix H Conjugate matrices, U be Ν χ Ν unitary matrice, ∑ be Ν χ Μ diagonal matrix, U^HFor the conjugate matrices of matrix U；

The K of matrix U is taken to arrange as described K feedback precoding vector, or, take any K of matrix U to arrange and carry out linear combination, obtain K feedback precoding vector.

24th, user equipment according to claim 21, it is characterised in that the feedback precoding vector determining module specifically for：

Coding vector after K of the down channel H is determined according to the down channel H；Precoding vector is fed back using the transposition of coding vector after the K of the down channel H as described K of H, or take any K row of the transposition of coding vector after K of down channel H to carry out linear combination, obtain K feedback precoding vector.

25th, the user equipment according to claim any one of 21-24, it is characterised in that also include：

Acquisition module, the running time-frequency resource position of the up precoding reference signal and the quantity K of the uplink reference signals are sent for obtaining.

26th, the user equipment according to claim any one of 21-25, it is characterised in that the precoding processing module specifically for：

According to described Κ feedback precoding vector, the reason that prelists is carried out to uplink reference signals according to below equation：

m

Wherein ,/_nRepresent time resource position, k_nFrequency resource position is represented, p represents the antenna serial number of the UE, and β represents amplitude adjusted coefficient, r^(m)Represent that m-th of uplink reference signals uses sequence of complex numbers, r^(m)(n) n-th of plural elements of the sequence of complex numbers, w are represented^(m)Represent the precoding vector that m-th of feedback reference signal is used, l≤m≤K, w^(m)(p) p-th of plural elements of the precoding vector that m-th of uplink reference signals are used are represented.

27th, a kind of base station, it is characterised in that including：

Transmitter, for sending downlink reference signal to each user equipment (UE), so that each UE carries out the down channel matrix H i that channel estimation obtains down channel according to the downlink reference signal

(i=l, 2 ... I), I is the quantity of UE in cell, and determines Ki feedback precoding vector according to the down channel matrix, wherein, the down channel matrix is matrix, M The antenna number used for the base station, Ni is the antenna number that i-th of UE is used, and M and Ni are positive integer, Ki is the quantity for the feedback reference signal that i-th of UE need to be sent, (Μ, Λ ^, the feedback precoding vector are matrix to 1≤≤ π ι；

Receiver, for receiving the Ki feedback reference signal that each UE is sent, wherein, each UE feedback reference signal is that the UE is obtained according to corresponding feedback precoding vector to uplink reference signals progress precoding processing；

Processor, for the feedback reference signal according to each UE, or, according to the up precoding reference signal of each each UE feedback reference signal and other UE, determine the downlink precoding matrix of each UE.

28th, base station according to claim 27, it is characterised in that the processor specifically for：

Channel estimation is carried out according to the Ki feedback reference signal of each UE respectively, determine the corresponding Ki up precoding vector of each UE wherein, h is i-th of UE k-th of up precoding vector, k=l, 2 ... Ki, h are Μ χ matrixes；

According to the corresponding Ki up precoding vector h of each UE_Lk, the feeding back precoding matrix of each UE is determined, wherein, the feeding back precoding matrix is MxKi matrix；

According to the feeding back precoding matrix of each UE, or, according to the feeding back precoding matrix of each UE and other UE feeding back precoding matrix, determine the downlink precoding matrix of each UE.

29th, base station according to claim 28, it is characterised in that the processor specifically for：

Ki up precoding vector h corresponding to each UE is normalized, and according to Ki up precoding vectors after each UE normalizeds!^ determines the feeding back precoding matrix of each UE.

30th, the base station according to any one of claim 27 or 28, it is characterised in that the processor specifically for：

The feeding back precoding matrix of each UE is combined, joint feeding back precoding matrix R, R=[QuQ is obtained₂... ^], wherein,（Represent i-th of UE feeding back precoding matrix；

The downlink precoding matrix P of each UE is determined according to below equation:

P = ( R R^H) R, R^HR conjugate matrices are represented,（X square of being inverted to matrix X) is represented Battle array computing.

31st, base station according to claim 27, it is characterised in that the transmitter is additionally operable to:Notify that each UE sends the feedback reference signal on specified running time-frequency resource position, and the feedback reference signal quantity K.

32nd, base station according to claim 31, it is characterised in that the transmitter specifically for：

Send reference signal to each UE and indicate message, the reference signal indicates to send the running time-frequency resource position of the feedback reference signal in message comprising the UE, and the feedback reference signal quantity Κ.

33rd, base station according to claim 31, it is characterised in that the transmitter specifically for：

The total running time-frequency resource taken to each UE feedback reference signals for sending the UE, and the running time-frequency resource of the occupancy of each feedback reference signal of the UE, so that total running time-frequency resource and the running time-frequency resource of the occupancy of each feedback reference signal that each UE takes according to the feedback reference signal determine the quantity Κ of the feedback reference signal.

34th, a kind of user equipment (UE), it is characterised in that including：

Receiver, the downlink reference signal for receiving base station transmission；

Processor, for carrying out the down channel matrix H that channel estimation obtains down channel according to the downlink reference signal, wherein, the down channel matrix H is NxM matrixes, M is the antenna number that the base station is used, and N is the antenna number that the UE is used, and M and N are positive integer；

K feedback precoding vector is determined according to the down channel matrix H, wherein, K is the quantity for the feedback reference signal that the UE need to be sent, and l≤≤ min (M, N), the feedback precoding vector is Nx l matrixes；

According to described K feedback precoding vector, precoding processing is carried out to uplink reference signals respectively, K feedback reference signal is obtained；

Transmitter, for sending the K feedback reference signal to the base station, so that the base station determines the downlink precoding matrix of the UE according to the K feedback reference signal.

35th, user equipment according to claim 34, it is characterised in that the processor specifically for：

Singular value decomposition is carried out to the down channel matrix H, H is obtained_nt = U∑V^H, wherein, U For NxN unitary matrice, V is Μ χ Μ unitary matrice, and ∑ is Ν χ Μ diagonal matrix；The Κ of matrix U is taken to arrange as described Κ feedback precoding vector, or, take any Κ of matrix U to arrange and carry out linear combination, obtain Κ feedback precoding vector.

36th, user equipment according to claim 34, it is characterised in that the processor specifically for：

By Η Η^ΗEigenvalues Decomposition is carried out, H^ HD=U ∑s U is obtained^H, wherein, H^HRepresenting matrix H conjugate matrices, U is NxN unitary matrice, and ∑ is NxM diagonal matrix, U^HFor the conjugate matrices of matrix U；

The K of matrix U is taken to arrange as described K feedback precoding vector, or, take any K of matrix U to arrange and carry out linear combination, obtain K feedback precoding vector.

37th, user equipment according to claim 34, it is characterised in that the processor specifically for：

Coding vector after K of the down channel H is determined according to the down channel H；Precoding vector is fed back using the transposition of coding vector after the K of the down channel H as described K of H, or take any K row of the transposition of coding vector after K of down channel H to carry out linear combination, obtain K feedback precoding vector.

38th, the user equipment according to claim any one of 34-37, it is characterised in that the processor is additionally operable to：

Obtain the quantity K of the running time-frequency resource position for sending the up precoding reference signal and the uplink reference signals.

39th, the user equipment according to claim any one of 34-37, it is characterised in that the processor specifically for：

According to described Κ feedback precoding vector, uplink reference signals are prelisted according to below equation：

M wherein ,/_nRepresent time resource position, k_nFrequency resource position is represented, p represents the antenna serial number of the UE, and β represents amplitude adjusted coefficient, r^(m)Represent that m-th of uplink reference signals uses sequence of complex numbers, r^(m)(n) n-th of plural elements of the sequence of complex numbers, w are represented^(m)Represent the precoding vector that m-th of feedback reference signal is used, l≤m≤K, w^(m)(p) represent on described m-th 42