CN103023605A - Method and device for precoding coordinated-multiple-point transmission - Google Patents

Abstract

The invention discloses a method and a device for precoding coordinated-multiple-point (CoMP) transmission. The method comprises the following steps that: a service base station receives an expected sub-precoding matrix indicator of a terminal under the service base station and a leakage sub-precoding matrix indicator of a terminal under a cooperation base station, wherein the leakage sub-precoding matrix indicator is transmitted by the cooperation base station, the expected sub-precoding matrix indicator corresponds to a coding code word in the direction of an expected terminal, and the leakage sub-precoding matrix indicator corresponds to a coding code word in an interference direction; the service base station selects an expected coding code word according to the expected sub-precoding matrix indicator and selects a leakage sub-precoding code word according to the leakage sub-precoding matrix indicator; and the service base station performs convolution on the expected coding code word and the leakage sub-precoding code word to obtain a precoding code word. By adopting the method and the device, the problem that the accuracy of reducing interferences caused by edge user terminals is low when the CoMP is realized in the prior art is solved, and then the effect of greatly improving the accuracy of reducing the interferences caused by the edge user terminals by adopting a CoMP technology is achieved.

Description

Coordinated multipoint transmission recoding processing method and device

Technical field

The present invention relates to the communications field, in particular to a kind of coordinated multipoint transmission recoding processing method and device.

Background technology

At 3Gpp Long Term Evolution (Long Term Evolution-Advanced, referred to as LTE-A) in the system, coordinated multipoint transmission (Coordinated Multiple Point is referred to as CoMP) technology can solve presence of intercell interference, improves cell edge and cell spectrum efficient.This technology is mainly for Cell Edge User, mutual by mobile subscriber's channel information between adjacent base station, adjacent base station takes certain interference avoidance strategy or a plurality of base station that the mobile subscriber is carried out the interference that joint transmission reduces edge customer to disturbed user, improves throughput and the spectrum utilization efficiency of cell edge data.

Fig. 1 is the application schematic diagram of CoMP technology in the correlation technique, and as shown in Figure 1, there are serving BS, cooperative base station in the base station.Wherein, H ₁₁The expression service cell eNB ₁To this community user UE ₁Channel, H ₂₁The expression service cell eNB ₁To adjacent cell user UE ₂Channel.Equally, H ₂₂Expression cooperation cell eNB ₂To this community user UE ₂Channel, H ₁₂Expression cooperation cell eNB ₂To adjacent cell user UE ₁Channel.

Usually, the CoMP uplink feedback adopts the form of partial feedback, i.e. the UE channel matrix that not exclusively feeds back the channel matrix of this residential quarter and not exclusively feed back adjacent cell, but feedback fraction channel information.Specifically, UE feeds back pre-coding matrix index (the Precoding Matrix Indicator of this cell channel, referred to as PMI), UE also feeds back the poorest precoding index (the Worst Companion Indicator to adjacent cell channel, referred to as WCI) realize the CoMP of terminal spatial domain Inter-Cell Interference Coordination, but code book optimizing mode is loaded down with trivial details when adopting the CoMP technology in the correlation technique, reduces the edge customer terminal when causing CoMP to realize and disturbs the not high problem of accuracy rate.

Summary of the invention

Code book optimizing mode is loaded down with trivial details when adopting the CoMP technology in the correlation technique, reduce the edge customer terminal when causing CoMP to realize and disturb the not high problem of accuracy rate, the invention provides a kind of coordinated multipoint transmission recoding processing method and device, to address the above problem at least.

According to an aspect of the present invention, a kind of coordinated multipoint transmission recoding processing method is provided, comprise, serving BS receives the sub-pre-coding matrix index of expectation of the terminal under this serving BS and the sub-pre-coding matrix index of leakage of the terminal under described cooperative base station that cooperative base station sends, wherein, the coding codeword that the described expectation corresponding expectation of sub-pre-coding matrix index terminal side makes progress, the coding codeword on the corresponding interference radiating way of the sub-pre-coding matrix index of described leakage; Described serving BS is selected the expectation coding codeword and is selected to leak sub-pre-encoding codeword according to the sub-pre-coding matrix index of described leakage according to the sub-pre-coding matrix index of described expectation; Described serving BS carries out convolution operation with described expectation coding codeword and the sub-pre-encoding codeword of described leakage, obtains described pre-encoding codeword.

Preferably, receive at serving BS before the sub-pre-coding matrix index of expectation of the terminal under this serving BS, comprise, the terminal under the described serving BS is estimated terminal under the described serving BS and the channel matrix between described serving BS; According to the channel matrix given period shop sign in the form of a streamer pre-encoding codeword between the terminal under the described serving BS and described serving BS; Obtain the sub-pre-coding matrix index of expectation according to the sub-pre-encoding codeword of described expectation.

Preferably, comprised before receiving the sub-pre-coding matrix index of the leakage in the terminal under the described cooperative base station that described cooperative base station sends that the terminal under the described cooperative base station is estimated terminal under the described cooperative base station and the channel matrix between serving BS; Calculate the sub-pre-encoding codeword of leakage according to the terminal under the described cooperative base station and the channel matrix between serving BS; Obtain the sub-pre-coding matrix index of leakage according to the sub-pre-encoding codeword of described leakage.

Preferably, comprise according to the channel matrix given period shop sign in the form of a streamer pre-encoding codeword between the terminal under the described serving BS and described serving BS, channel matrix between the terminal under the described serving BS and described serving BS is carried out singular value decomposition, obtain channel estimating code word matrix; Travel through the channel estimating code word in the described channel estimating code word matrix, obtain the distance of code word in described channel estimating code word and the code book; Determine that code word schedules to last the shop sign in the form of a streamer pre-encoding codeword apart from the channel estimating code word of minimum.

Preferably, comprise according to the terminal under the described cooperative base station and the sub-pre-encoding codeword of the calculating of the channel matrix between serving BS leakage, the terminal under the described cooperative base station and the channel matrix between serving BS are carried out singular value decomposition, obtain channel estimating code word matrix; Travel through the channel estimating code word in the described channel estimating code word matrix, obtain the distance of code word in described channel estimating code word and the code book; Determine that code word is the sub-pre-encoding codeword of leakage apart from the channel estimating code word of maximum.

Preferably, at described serving BS described expectation coding codeword and the sub-pre-encoding codeword of described leakage are carried out convolution operation, obtain after the described pre-encoding codeword, carry out precoding processing to transmitting according to described pre-encoding codeword.

According to a further aspect in the invention, a kind of coordinated multipoint transmission precoding processing device is provided, comprise, receiver module, be used for serving BS and receive the sub-pre-coding matrix index of expectation of the terminal under this serving BS and the sub-pre-coding matrix index of leakage of the terminal under described cooperative base station that cooperative base station sends, wherein, the coding codeword that the described expectation corresponding expectation of sub-pre-coding matrix index terminal side makes progress, the coding codeword on the corresponding interference radiating way of the sub-pre-coding matrix index of described leakage; Select module, be connected to described receiver module, be used for described serving BS and select the expectation coding codeword and select to leak sub-pre-encoding codeword according to the sub-pre-coding matrix index of described leakage according to the sub-pre-coding matrix index of described expectation; The convolution operation module is connected to described selection module, is used for described serving BS described expectation coding codeword and the sub-pre-encoding codeword of described leakage are carried out convolution operation, obtains described pre-encoding codeword.

Preferably, comprise also that estimation module is used for terminal under the described serving BS and estimates terminal under the described serving BS and the channel matrix between described serving BS; Computing module is connected to described estimation module, is used for according to the channel matrix given period shop sign in the form of a streamer pre-encoding codeword between the terminal under the described serving BS and described serving BS; Acquisition module is connected to described computing module, is used for obtaining the sub-pre-coding matrix index of expectation according to the sub-pre-encoding codeword of described expectation.

Preferably, described estimation module also is used for terminal under the described cooperative base station and estimates terminal under the described cooperative base station and the channel matrix between serving BS; Described computing module also is used for calculating the sub-pre-encoding codeword of leakage according to the terminal under the described cooperative base station and the channel matrix between serving BS; Described acquisition module also is used for obtaining the sub-pre-coding matrix index of leakage according to the sub-pre-encoding codeword of described leakage.

Preferably, described computing module comprises, decomposing module is used for the channel matrix between the terminal under the described serving BS and described serving BS is carried out singular value decomposition, obtains channel estimating code word matrix; Spider module is connected to described decomposing module, is used for traveling through the channel estimating code word of described channel estimating code word matrix, obtains the distance of code word in described channel estimating code word and the code book; Determination module is connected to described spider module, is used for determining that code word schedules to last the shop sign in the form of a streamer pre-encoding codeword apart from the channel estimating code word of minimum.

Preferably, described decomposing module also is used for the terminal under the described cooperative base station and the channel matrix between serving BS are carried out singular value decomposition, obtains channel estimating code word matrix; Described spider module also for the channel estimating code word that travels through described channel estimating code word matrix, obtains the distance of code word in described channel estimating code word and the code book; Described determination module is used for also determining that code word is the sub-pre-encoding codeword of leakage apart from the channel estimating code word of maximum.

Preferably, also comprise precoding module, be connected to described convolution operation module, be used at described serving BS described expectation coding codeword and the sub-pre-encoding codeword of described leakage being carried out convolution operation, obtain after the described pre-encoding codeword, carry out precoding processing to transmitting according to described pre-encoding codeword.

By the present invention, adopt serving BS to receive the sub-pre-coding matrix index of expectation of the terminal under this serving BS and the sub-pre-coding matrix index of leakage of the terminal under described cooperative base station that cooperative base station sends, wherein, the coding codeword that the described expectation corresponding expectation of sub-pre-coding matrix index terminal side makes progress, the coding codeword on the corresponding interference radiating way of the sub-pre-coding matrix index of described leakage; Described serving BS is selected the expectation coding codeword and is selected to leak sub-pre-encoding codeword according to the sub-pre-coding matrix index of described leakage according to the sub-pre-coding matrix index of described expectation; Described serving BS carries out convolution operation with described expectation coding codeword and the sub-pre-encoding codeword of described leakage, obtain described pre-encoding codeword, code book optimizing mode is loaded down with trivial details when having solved available technology adopting CoMP technology, reduce the edge customer terminal when causing CoMP to realize and disturb the not high problem of accuracy rate, and then when having reached employing CoMP technology, make and reduce the edge customer terminal and disturb the larger raising effect of accuracy rate.

Description of drawings

Accompanying drawing described herein is used to provide a further understanding of the present invention, consists of the application's a part, and illustrative examples of the present invention and explanation thereof are used for explaining the present invention, do not consist of improper restriction of the present invention.In the accompanying drawings:

Fig. 1 is the application schematic diagram of CoMP technology in the correlation technique;

Fig. 2 is the flow chart according to the coordinated multipoint transmission recoding processing method of the embodiment of the invention;

Fig. 3 is the structured flowchart according to the coordinated multipoint transmission precoding processing device of the embodiment of the invention;

Fig. 4 is the structured flowchart according to the coordinated multipoint transmission precoding processing device one of the embodiment of the invention;

Fig. 5 is the structured flowchart according to the computing module of the coordinated multipoint transmission precoding processing device of the embodiment of the invention;

Fig. 6 is the structured flowchart according to the coordinated multipoint transmission precoding processing device two of the embodiment of the invention;

Fig. 7 is the flow chart of coordinated multipoint transmission recoding processing method according to the preferred embodiment of the invention;

Fig. 8 is the schematic diagram based on the CoMP precoding implementation result of code book according to the embodiment of the invention;

Fig. 9 is the structured flowchart of CoMP pre-coding apparatus according to the preferred embodiment of the invention.

Embodiment

Hereinafter also describe in conjunction with the embodiments the present invention in detail with reference to accompanying drawing.Need to prove that in the situation of not conflicting, embodiment and the feature among the embodiment among the application can make up mutually.

A kind of coordinated multipoint transmission recoding processing method is provided in the present embodiment, and Fig. 2 is the flow chart according to the coordinated multipoint transmission recoding processing method of the embodiment of the invention, and as shown in Figure 2, this flow process comprises the steps:

Step S202, serving BS receives the sub-pre-coding matrix index of expectation of the terminal under this serving BS and the sub-pre-coding matrix index of leakage of the terminal under this cooperative base station that cooperative base station sends, wherein, expect the coding codeword that the corresponding expectation of sub-pre-coding matrix index terminal side makes progress, leak the coding codeword on the corresponding interference radiating way of sub-pre-coding matrix index, this expectation terminal is the terminal of serving BS expectation transmitted signal;

Step S204, serving BS is selected the expectation coding codeword and is selected to leak sub-pre-encoding codeword according to leaking sub-pre-coding matrix index according to the sub-pre-coding matrix index of expectation;

Step S206, serving BS will expect that coding codeword and the sub-pre-encoding codeword of leakage carry out convolution operation, obtain pre-encoding codeword.

Pass through above-mentioned steps, according to channel information, when the structure pre-encoding codeword, pre-encoding codeword is divided into the expectation coding codeword and leaks sub-pre-encoding codeword, making transmits more concentrates on the expectation coding codeword that the desired user terminal side makes progress, and as far as possible little in the interference signal of leaking on the sub-pre-encoding codeword, so that when adopting the CoMP technology, make and reduce the edge customer terminal and disturb accuracy rate to obtain larger raising.

As a more excellent execution mode, receive at serving BS before the sub-pre-coding matrix index of expectation of the terminal under this serving BS, obtain to expect sub-pre-coding matrix index by the terminal under the serving BS, comprise the terminal under the terminal estimation serving BS under the serving BS and the channel matrix between serving BS; According to the terminal under the serving BS and the channel matrix given period shop sign in the form of a streamer pre-encoding codeword between serving BS; Obtain the sub-pre-coding matrix index of expectation according to the sub-pre-encoding codeword of expectation.Certainly carry out above-mentioned steps and obtain to expect that sub-pre-coding matrix index also can obtain at serving BS.When if base station and user terminal all need this to expect sub-pre-coding matrix index, can realize by the mode of interactive information.Here obtain to expect sub-pre-coding matrix index and leak sub-pre-coding matrix index by the mode to the channel matrix singular value decomposition, can certainly obtain to expect sub-pre-coding matrix index by other Mathematical treatment and leak sub-pre-coding matrix index, thereby obtain expecting sub-pre-encoding codeword and reveal sub-pre-encoding codeword, can select according to concrete demand.

Equally, before the sub-pre-coding matrix index of the leakage in the terminal under the cooperative base station that receives the cooperative base station transmission, also can obtain to leak pre-coding matrix index by same processing mode, specifically comprise the steps the terminal under the terminal estimation cooperative base station under the cooperative base station and the channel matrix between serving BS; Calculate the sub-pre-encoding codeword of leakage according to the terminal under the cooperative base station and the channel matrix between serving BS; Obtain the sub-pre-coding matrix index of leakage according to leaking sub-pre-encoding codeword.

Mode according to the terminal under the serving BS and the channel matrix given period shop sign in the form of a streamer pre-encoding codeword between serving BS is a lot, introduce the mathematical processing methods of singular value decomposition here, for example, terminal under the serving BS and the channel matrix between serving BS are carried out the singular value decomposition of mathematical theorem, obtain channel estimating code word matrix; Wherein, this channel estimating code word matrix is the part of V matrix, the channel estimating code word in the traversal channel estimating code word matrix, the distance of code word in acquisition channel estimating code word and the code book; Determine that code word schedules to last the shop sign in the form of a streamer pre-encoding codeword apart from the channel estimating code word of minimum.Namely find out the code word the most similar to the channel estimating code word by corresponding with the code word in the codebook set, and with it as the sub-pre-encoding codeword of expectation, mode relatively also can be a lot, for example, can by general Mathematical treatment mode, also can adopt some other artificial treatment mode.

In like manner, when calculating the sub-pre-encoding codeword of leakage, identical processing mode is arranged also, for example, the terminal under the cooperative base station and the channel matrix between serving BS are carried out singular value decomposition, obtain channel estimating code word matrix; Channel estimating code word in the traversal channel estimating code word matrix, the distance of code word in acquisition channel estimating code word and the code book; Determine that code word is the sub-pre-encoding codeword of leakage apart from the channel estimating code word of maximum.

Preferably, will expect that at serving BS coding codeword and the sub-pre-encoding codeword of leakage carry out convolution operation, obtain after the pre-encoding codeword, carry out precoding processing to transmitting according to pre-encoding codeword.By such processing, the energy centralization (or perhaps transmitting power is concentrated) that the expectation precoding is upwards transmitted in the desired user terminal side, and the value that transmits on its interference radiating way in the leakage precoding is tried one's best close to zero, make edge customer obtain high as far as possible signal to noise ratio, obtain certain inhibition at interference radiating way.

A kind of coordinated multipoint transmission precoding processing device also is provided in the present embodiment, and this device is used for realizing above-described embodiment and preferred implementation, had carried out repeating no more of explanation.As used below, the combination of software and/or the hardware of predetermined function can be realized in term " module ".Although the described device of following examples is preferably realized with software, hardware, perhaps the realization of the combination of software and hardware also may and be conceived.Fig. 3 is the structured flowchart according to the coordinated multipoint transmission precoding processing device of the embodiment of the invention, and as shown in Figure 3, this device comprises, receiver module 32, selection module 34 and convolution operation module 36, and the below describes this device.

Receiver module 32, be used for serving BS and receive the sub-pre-coding matrix index of expectation of the terminal under this serving BS and the sub-pre-coding matrix index of leakage of the terminal under cooperative base station that cooperative base station sends, wherein, expect the coding codeword that the corresponding expectation of sub-pre-coding matrix index terminal side makes progress, leak the coding codeword on the corresponding interference radiating way of sub-pre-coding matrix index;

Select module 34, be connected to receiver module 32, be used for serving BS and select the expectation coding codeword and select to leak sub-pre-encoding codeword according to leaking sub-pre-coding matrix index according to the sub-pre-coding matrix index of expectation;

Convolution operation module 36 is connected to and selects module 34, is used for serving BS and will expects that coding codeword and the sub-pre-encoding codeword of leakage carry out convolution operation, obtain pre-encoding codeword.

Fig. 4 is the structured flowchart according to the coordinated multipoint transmission precoding processing device one of the embodiment of the invention, and as shown in Figure 4, this device is except comprising that the module among Fig. 3 also comprises estimation module 42, computing module 44 and acquisition module 46.The below describes other module in this device.

Estimation module 42 is for the terminal under the estimation of the terminal under the serving BS serving BS and the channel matrix between serving BS;

Computing module 44 is connected to estimation module 42, is used for according to the terminal under the serving BS and the channel matrix given period shop sign in the form of a streamer pre-encoding codeword between serving BS;

Acquisition module 46 is connected to computing module 44, is used for obtaining the sub-pre-coding matrix index of expectation according to the sub-pre-encoding codeword of expectation.

Preferably, this estimation module 42 is also for the terminal under the estimation of the terminal under the cooperative base station cooperative base station and the channel matrix between serving BS; This computing module 44 also is used for calculating the sub-pre-encoding codeword of leakage according to the terminal under the cooperative base station and the channel matrix between serving BS; This acquisition module 46 also is used for obtaining the sub-pre-coding matrix index of leakage according to leaking sub-pre-encoding codeword.

Fig. 5 is the structured flowchart according to the computing module of the coordinated multipoint transmission precoding processing device of the embodiment of the invention, and as shown in Figure 5, this computing module 44 comprises decomposing module 52, spider module 54 and determination module 56.The below describes this computing module.Decomposing module 52 is used for the terminal under the serving BS and the channel matrix between serving BS are carried out singular value decomposition, obtains channel estimating code word matrix; Spider module 54 is connected to decomposing module 52, is used for the channel estimating code word of traversal channel estimating code word matrix, obtains the distance of code word in channel estimating code word and the code book; Determination module 56 is connected to spider module 54, is used for determining that code word schedules to last the shop sign in the form of a streamer pre-encoding codeword apart from the channel estimating code word of minimum.

Preferably, this decomposing module 52 also is used for the terminal under the cooperative base station and the channel matrix between serving BS are carried out singular value decomposition, obtains channel estimating code word matrix; This spider module 54 also for the channel estimating code word of traversal channel estimating code word matrix, obtains the distance of code word in channel estimating code word and the code book; This determination module 56 is used for also determining that code word is the sub-pre-encoding codeword of leakage apart from the channel estimating code word of maximum.

Fig. 6 is the structured flowchart according to the coordinated multipoint transmission precoding processing device two of the embodiment of the invention, and as shown in Figure 6, this device comprises except module among Fig. 3 and also comprises precoding module 62.This precoding module 62 is connected to convolution operation module 36, is used for will expecting that at serving BS coding codeword and the sub-pre-encoding codeword of leakage carry out convolution operation, obtains after the pre-encoding codeword, carries out precoding processing to transmitting according to pre-encoding codeword.

A kind of CoMP precoding implementation method based on code word range search code book is provided in this preferred embodiment, according to channel information, when the structure pre-encoding codeword, the pre-encoding codeword equivalence that will transmit to the user is the form of 2 sub-precodings, sub-precoding forming energy on the desired user direction is assembled, another sub-precoding then forms zero at each interference radiating way and falls into, thereby obtain high as far as possible Signal to Interference plus Noise Ratio at the desired user receiving terminal, suppress to disturb at each interference radiating way simultaneously.The below describes the method.

Need to prove, in this preferred embodiment, suppose to have K eNB, a UE is only served in each residential quarter, and the UE of each residential quarter service uses same running time-frequency resource, and each eNB all has the M transmit antennas, k user comprises Nk root reception antenna, and user k need to transmit m _kIndividual independently data flow.Certain eNB _k(k=1,2 ... the signal that K) sends can be expressed as M dimensional vector W _ks _k, wherein, W _kM * m for user k _kThe dimension pre-coding matrix, and satisfy

The computing of tr () expression mark, superscript H represents conjugate transpose computing, s _kThe m of user k _kDimension emission symbolic vector.

For two residential quarter two users, suppose user UE ₁For desired user is without loss of generality, then to user UE ₁The implementation procedure of precoding be described below:

S1 estimates channel.

To serving BS eNB ₁, this community user UE ₁Estimate and serving BS eNB ₁Between channel matrix H ₁₁And and cooperative base station eNB ₂Between channel matrix H ₁₂

To cooperative base station eNB ₂, this community user UE ₂Estimate and serving BS eNB ₂Between channel matrix H ₂₂And and cooperative base station eNB ₁Between channel matrix H ₂₁

S2, given period shop sign in the form of a streamer pre-encoding codeword.

(1) at UE ₁Side is from the inner code word of choosing of code book (as determining the LTE agreement) of precoding, the code word W in the traversal code book _i(wherein i is the code word sequence number in the corresponding code book).

With channel matrix H ₁₁Carry out singular value decomposition, namely

Obtain channel estimating code word matrix:

Wherein

Be V ₁₁Front m _kRow, H ₁₁UE1 user and this cell base station eNB ₁Between N _k* M ties up channel matrix, U ₁₁N _k* M ties up unitary matrice, V ₁₁That M * M ties up unitary matrice, ∈ ₁₁=diag (σ ₁, σ ₂... σ _r), r=rank (H ₁₁), diag represents diagonal matrix, rank represents order computing, σ ₁, σ ₂... σ _rIt is channel matrix H ₁₁Singular value.

Then travel through the channel estimating code word

With code word W in the code book _iDistance, code word apart from minimum be the expectation sub-pre-encoding codeword estimated value W ₁₁:

Wherein superscript H represents the conjugate transpose operator, and Z is code word W in the code book _iDimension.

The codeword selection of corresponding () intermediate value minimum of expression schedules to last the estimated value W of shop sign in the form of a streamer pre-encoding codeword ₁₁, corresponding pre-coding matrix index is PMI ₁₁, UE1 is to this cell base station eNB1 feedback PMI ₁₁

Similar, at UE ₂Side is with channel matrix H ₂₂Carry out singular value decomposition, obtain channel estimating code word matrix

Further obtain expecting sub-pre-encoding codeword W ₂₂:

Corresponding pre-coding matrix index is PMI ₂₂, UE ₂To this cell base station eNB ₂Feedback PMI ₂₂

S3 estimates to leak sub-pre-encoding codeword.

At UE ₁Side is from the inner code word of choosing of code book (as determining the LTE agreement) of precoding, the code word W in the traversal code book _i(wherein i is the code word sequence number in the corresponding code book) is with channel matrix H ₁₂Carry out singular value decomposition, obtain channel estimating code word matrix

Further calculate the channel estimating code word

With code word W in the code book _iDistance, code word is then leaked sub-pre-encoding codeword W apart from being of maximum ₁₂: $W_{12}=\arg \underset{W_i}{\max }{[Z-\mathrm{tr}{\{\left({W_i^{H}W}_{H_{12}}\right)}^H\left({W_i^{H}W}_{H_{12}}\right)\}]}^{1/2},$ Wherein

The codeword selection of corresponding () intermediate value maximum of expression is for leaking sub-pre-encoding codeword W ₁₂, corresponding pre-coding matrix index is WCI ₁₂, UE ₁To this cell base station eNB ₁Feedback WCI ₁₂

Similar, at UE ₂Side is with channel matrix H ₂₁Carry out singular value decomposition, obtain channel estimating code word matrix

Further obtain leaking sub-pre-encoding codeword W ₂₁: ${\mathrm{<figure-callout\; id="21"\; label="W"\; filenames="HDA0000093528860000061.png"\; state="\{\{state\}\}">W</figure-callout>}}_{21}=\arg \underset{W_i}{\max }{[Z-\mathrm{tr}{\{\left({W_i^{H}W}_{H_{21}}\right)}^H\left({W_i^{H}W}_{H_{21}}\right)\}]}^{1/2},$ Corresponding pre-coding matrix index is WCI ₂₁, UE ₂To this cell base station eNB ₂Feedback WCI ₂₁

S4, information interaction.

Serving BS eNB ₁With cooperative base station eNB ₂By the interface between base station and base station (X2 interface) interactive channel information, i.e. base station eNB ₁To base station eNB ₂Transmit pre-coding matrix index WCI ₁₂, base station eNB ₂To base station eNB ₁Transmit pre-coding matrix index WCI ₂₁

S5, the structure pre-encoding codeword.

In base station eNB ₁To expect pre-encoding codeword W ₁₁With leakage pre-encoding codeword W ₂₁Carry out convolution, the gained matrix is as pre-encoding codeword.Thereby guarantee desired user signal power maximum, disturb to be suppressed to level off to zero.For residential quarter eNB ₁Corresponding this community user UE ₁, adjacent cell user UE ₂Precoding, namely

In the formula

Expression is to matrix W ₁₁And matrix W ₁₁Ask convolution, and get ranks and W at the matrix of consequence core ₁₁Identical part consists of matrix.

S6 carries out signal to launch after the precoding.

By this preferred embodiment, when the CoMP of LTE-Advanced system precoding, pre-coding matrix index according to the UE feedback, select the expectation pre-encoding codeword, by the pre-coding matrix index that adjacent cell is come alternately, select to leak pre-encoding codeword, will expect that then the pre-encoding codeword matrix carries out convolution with leakage pre-encoding codeword matrix and obtains precoding, can guarantee desired user signal power maximum, disturb to be suppressed to level off to zero.

In the CoMP of this preferred embodiment precoding, when considering that simultaneously the precoding gain of this community user is larger, also take into account adjacent cell with the zero leakage of time-frequency resource user, according to channel information, when the structure pre-encoding codeword, to be expectation pre-encoding codeword and the convolution form of leaking pre-encoding codeword to the precoding processing equivalence that the user transmits, expectation precoding forming energy on the desired user direction converges, leak precoding and then form zero leakage at each interference radiating way, thereby obtain high as far as possible Signal to Interference plus Noise Ratio at the desired user receiving terminal, suppress to disturb at each interference radiating way simultaneously.

In this preferred embodiment, take the situation of two base station cells as example describes, need to prove, CoMP precoding implementation method under two cell scenario that in the preferred embodiment, provide, wherein the number of transmit antennas of eNB1, eNB2 is 4, UE ₁, UE ₂Reception antenna is 2, and the number of plies of each UE is that 2, Fig. 7 is the flow chart of coordinated multipoint transmission recoding processing method according to the preferred embodiment of the invention, and as shown in Figure 7, this flow process comprises the steps:

Step S702 estimates base station eNB ₁With this community user UE ₁Between channel matrix H ₁₁And base station eNB ₁With adjacent cell user UE ₂Between channel matrix H ₂₁

To cooperation cell eNB ₂, estimate cooperation cell eNB ₂With this community user UE ₂Between channel matrix H ₂₂And cooperation cell eNB ₂With adjacent cell user UE ₂Between channel matrix H ₁₂

Step S704 estimates the expectation pre-encoding codeword, at UE ₁Side is with channel matrix H ₁₁Carry out singular value decomposition, namely

Obtain channel estimating code word matrix: V wherein _{11, [2]}Be V ₁₁Front 2 row of matrix, H ₁₁The dimension of 2 * 4 between UE1 user and this cell base station eNB1 channel matrix, U ₁₁2 * 4 dimension unitary matrice, V ₁₁4 * 4 dimension unitary matrice, ∈ ₁₁=diag (σ ₁, σ ₂), 2=rank (H ₁₁), diag () represents diagonal matrix, the computing of rank () expression order, σ ₁, σ ₂It is channel matrix H ₁₁Singular value.

Then travel through the channel estimating code word

With the distance of a certain code word in the code book, code word is apart from the estimated value W that is the sub-pre-encoding codeword of expectation of minimum ₁₁: $W_{11}=\arg \underset{W_i}{\min }{[Z-\mathrm{tr}{\{\left({W_i^{H}W}_{H_{11}}\right)}^H\left({W_i^{H}W}_{H_{11}}\right)\}]}^{1/2},$ Wherein superscript H represents the conjugate transpose operator, and Z is code word W in the code book _iDimension.

The codeword selection of corresponding () intermediate value minimum of expression schedules to last the estimated value W of shop sign in the form of a streamer pre-encoding codeword ₁₁, corresponding pre-coding matrix index is PMI ₁₁, UE1 is to this cell base station eNB1 feedback PMI ₁₁

Similar, at UE ₂Side obtains expecting sub-pre-encoding codeword W ₂₂: ${\mathrm{<figure-callout\; id="22"\; label="W"\; filenames="HDA0000093528860000061.png"\; state="\{\{state\}\}">W</figure-callout>}}_{22}=\arg \underset{W_i}{\min }{[Z-\mathrm{tr}{\{\left({W_i^{H}W}_{H_{22}}\right)}^H\left({W_i^{H}W}_{H_{22}}\right)\}]}^{1/2},$ Corresponding pre-coding matrix index is PMI ₂₂, UE ₂To this cell base station eNB ₂Feedback PMI ₂₂

Step S706 estimates to leak pre-encoding codeword W ₁₂

Estimate to leak pre-encoding codeword, in the UE1 side, from the inner code word of choosing of code book (as determining the LTE agreement) of precoding, the code word W in the traversal code book _i(wherein i is the code word sequence number pre-encoding codeword W in the corresponding code book ₁₂: $W_{12}=\arg \underset{W_i}{\max }{[Z-\mathrm{tr}{\{\left({W_i^{H}W}_{H_{12}}\right)}^H\left({W_i^{H}W}_{H_{12}}\right)\}]}^{1/2},$ Wherein

The codeword selection of corresponding () intermediate value maximum of expression is for leaking sub-pre-encoding codeword W ₁₂, corresponding pre-coding matrix index is WCI ₁₂, UE1 is to this cell base station eNB1 feedback WCI ₁₂

Similar, in the UE2 side, obtain leaking sub-pre-encoding codeword W ₂₁: ${\mathrm{<figure-callout\; id="21"\; label="W"\; filenames="HDA0000093528860000061.png"\; state="\{\{state\}\}">W</figure-callout>}}_{21}=\arg \underset{W_i}{\max }{[Z-\mathrm{tr}{\{\left({W_i^{H}W}_{H_{21}}\right)}^H\left({W_i^{H}W}_{H_{21}}\right)\}]}^{1/2},$ Corresponding pre-coding matrix index is WCI ₂₁, UE2 is to this cell base station eNB2 feedback WCI ₂₁

Step S708, information interaction, serving BS eNB1 and cooperative base station eNB2 are by X2 mouth interactive channel information, and namely base station eNB 1 is transmitted pre-coding matrix index WCI to base station eNB 2 ₁₂, base station eNB 2 is transmitted pre-coding matrix index WCI to base station eNB 1 ₂₁

Step S710, the structure pre-encoding codeword is by expectation pre-encoding codeword W ₁With leakage pre-encoding codeword W ₂Between mapping, obtain the pre-encoding codeword of corresponding this community user UE1 of base station eNB 1, adjacent cell user UE2, namely In the formula

Expression is to matrix W ₁₁And matrix W ₂₁Ask convolution, and get ranks and W in the matrix of consequence central part ₁₁The part that size is identical consists of matrix.

Step S712, precoding processing is for base station eNB ₁, according to the pre-encoding codeword W that estimates to obtain ₁₁X carries out precoding processing, i.e. W to transmitting ₁X.

For cooperative base station eNB ₂, its processing procedure and base station eNB ₁Similar, no longer narration here.

Fig. 8 is the schematic diagram based on the CoMP precoding implementation result of code book according to the embodiment of the invention, as shown in Figure 8, and for serving BS eNB ₁, energy centralization is to this community user UE after the precoding ₁, zero falls into trend adjacent cell user UE ₂For cooperative base station eNB ₂, energy centralization is to this community user UE after the precoding ₂, zero falls into trend adjacent cell user UE ₁

A kind of precoding implement device also is provided in this preferred embodiment, has been applied to the LTE-Advanced system.Fig. 9 is the structured flowchart of CoMP pre-coding apparatus according to the preferred embodiment of the invention, as shown in Figure 9, this device comprises: channel estimation module 90, expectation pre-encoding codeword and leakage pre-encoding codeword are estimated and feedback module 92, channel information interactive module 94, precoding constructing module 96 and precoding processing module 98, the below is described in detail said structure.

Channel estimation module 90 is for service cell eNB ₁, be used for estimating user UE1 and base station eNB ₁Between channel matrix H ₁₁And estimating user UE ₁With base station eNB ₂Between channel matrix H ₁₂

Equally, to cooperation cell UE ₂, be used for estimating user UE ₂With base station eNB ₂Between channel matrix H ₂₂And estimating user UE2 and base station eNB ₁Between channel matrix H ₂₁

Expectation pre-encoding codeword and leak pre-encoding codeword and estimate and feedback module 92 is connected to channel estimation module 90, be used for according to the delivery channel of channel estimation module 90 set up with expectation precoding and leakage precoding between relation.

Channel information interactive module 94 is connected to the expectation pre-encoding codeword and leaks pre-encoding codeword and estimates and feedback module 92, is used for the mutual transmission of channel information.

Precoding constructing module 96 is connected to channel information interactive module 94, is used for generating pre-encoding codeword.

Precoding processing module 98 is connected to precoding constructing module 96, is used for the CoMP precoding of residential quarter.

The practical function of the modules of the above device does not repeat them here referring to the specific implementation process of said method.

Obviously, those skilled in the art should be understood that, above-mentioned each module of the present invention or each step can realize with general calculation element, they can concentrate on the single calculation element, perhaps be distributed on the network that a plurality of calculation elements form, alternatively, they can be realized with the executable program code of calculation element, thereby, they can be stored in the storage device and be carried out by calculation element, and in some cases, can carry out step shown or that describe with the order that is different from herein, perhaps they are made into respectively each integrated circuit modules, perhaps a plurality of modules in them or step are made into the single integrated circuit module and realize.Like this, the present invention is not restricted to any specific hardware and software combination.

The above is the preferred embodiments of the present invention only, is not limited to the present invention, and for a person skilled in the art, the present invention can have various modifications and variations.Within the spirit and principles in the present invention all, any modification of doing, be equal to replacement, improvement etc., all should be included within protection scope of the present invention.

Claims (12)

1. a coordinated multipoint transmission recoding processing method is characterized in that comprising,

Serving BS receives the sub-pre-coding matrix index of expectation of the terminal under this serving BS and the sub-pre-coding matrix index of leakage of the terminal under described cooperative base station that cooperative base station sends, wherein, the coding codeword that the described expectation corresponding expectation of sub-pre-coding matrix index terminal side makes progress, the coding codeword on the corresponding interference radiating way of the sub-pre-coding matrix index of described leakage;

Described serving BS is selected the expectation coding codeword and is selected to leak sub-pre-encoding codeword according to the sub-pre-coding matrix index of described leakage according to the sub-pre-coding matrix index of described expectation;

Described serving BS carries out convolution operation with described expectation coding codeword and the sub-pre-encoding codeword of described leakage, obtains described pre-encoding codeword.

2. method according to claim 1 is characterized in that, receives at serving BS before the sub-pre-coding matrix index of expectation of the terminal under this serving BS, comprise,

Terminal under the described serving BS is estimated terminal under the described serving BS and the channel matrix between described serving BS;

According to the channel matrix given period shop sign in the form of a streamer pre-encoding codeword between the terminal under the described serving BS and described serving BS;

Obtain the sub-pre-coding matrix index of expectation according to the sub-pre-encoding codeword of described expectation.

3. method according to claim 1 is characterized in that, before the sub-pre-coding matrix index of the leakage in the terminal under the described cooperative base station that receives described cooperative base station transmission, comprise,

Terminal under the described cooperative base station is estimated terminal under the described cooperative base station and the channel matrix between serving BS;

Calculate the sub-pre-encoding codeword of leakage according to the terminal under the described cooperative base station and the channel matrix between serving BS;

Obtain the sub-pre-coding matrix index of leakage according to the sub-pre-encoding codeword of described leakage.

4. method according to claim 2 is characterized in that, comprise according to the channel matrix given period shop sign in the form of a streamer pre-encoding codeword between the terminal under the described serving BS and described serving BS,

Channel matrix between the terminal under the described serving BS and described serving BS is carried out singular value decomposition, obtain channel estimating code word matrix;

Travel through the channel estimating code word in the described channel estimating code word matrix, obtain the distance of code word in described channel estimating code word and the code book;

Determine that code word schedules to last the shop sign in the form of a streamer pre-encoding codeword apart from the channel estimating code word of minimum.

5. method according to claim 3 is characterized in that, comprise according to the terminal under the described cooperative base station and the sub-pre-encoding codeword of the calculating of the channel matrix between serving BS leakage,

Terminal under the described cooperative base station and the channel matrix between serving BS are carried out singular value decomposition, obtain channel estimating code word matrix;

Travel through the channel estimating code word in the described channel estimating code word matrix, obtain the distance of code word in described channel estimating code word and the code book;

Determine that code word is the sub-pre-encoding codeword of leakage apart from the channel estimating code word of maximum.

6. method according to claim 1, it is characterized in that, at described serving BS described expectation coding codeword and the sub-pre-encoding codeword of described leakage are carried out convolution operation, obtain after the described pre-encoding codeword, carry out precoding processing to transmitting according to described pre-encoding codeword.

7. a coordinated multipoint transmission precoding processing device is characterized in that comprising,

Receiver module, be used for serving BS and receive the sub-pre-coding matrix index of expectation of the terminal under this serving BS and the sub-pre-coding matrix index of leakage of the terminal under described cooperative base station that cooperative base station sends, wherein, the coding codeword that the described expectation corresponding expectation of sub-pre-coding matrix index terminal side makes progress, the coding codeword on the corresponding interference radiating way of the sub-pre-coding matrix index of described leakage;

Select module, be connected to described receiver module, be used for described serving BS and select the expectation coding codeword and select to leak sub-pre-encoding codeword according to the sub-pre-coding matrix index of described leakage according to the sub-pre-coding matrix index of described expectation;

The convolution operation module is connected to described selection module, is used for described serving BS described expectation coding codeword and the sub-pre-encoding codeword of described leakage are carried out convolution operation, obtains described pre-encoding codeword.

8. device according to claim 7 is characterized in that, also comprise,

Estimation module is used for terminal under the described serving BS and estimates terminal under the described serving BS and the channel matrix between described serving BS;

Computing module is connected to described estimation module, is used for according to the channel matrix given period shop sign in the form of a streamer pre-encoding codeword between the terminal under the described serving BS and described serving BS;

Acquisition module is connected to described computing module, is used for obtaining the sub-pre-coding matrix index of expectation according to the sub-pre-encoding codeword of described expectation.

9. device according to claim 8 is characterized in that,

Described estimation module also is used for terminal under the described cooperative base station and estimates terminal under the described cooperative base station and the channel matrix between serving BS;

Described computing module also is used for calculating the sub-pre-encoding codeword of leakage according to the terminal under the described cooperative base station and the channel matrix between serving BS;

Described acquisition module also is used for obtaining the sub-pre-coding matrix index of leakage according to the sub-pre-encoding codeword of described leakage.

10. device according to claim 8 is characterized in that, described computing module comprises,

Decomposing module is used for the channel matrix between the terminal under the described serving BS and described serving BS is carried out singular value decomposition, obtains channel estimating code word matrix;

Spider module is connected to described decomposing module, is used for traveling through the channel estimating code word of described channel estimating code word matrix, obtains the distance of code word in described channel estimating code word and the code book;

Determination module is connected to described spider module, is used for determining that code word schedules to last the shop sign in the form of a streamer pre-encoding codeword apart from the channel estimating code word of minimum.

11. device according to claim 10 is characterized in that,

Described decomposing module also is used for the terminal under the described cooperative base station and the channel matrix between serving BS are carried out singular value decomposition, obtains channel estimating code word matrix;

Described spider module also for the channel estimating code word that travels through described channel estimating code word matrix, obtains the distance of code word in described channel estimating code word and the code book;

Described determination module is used for also determining that code word is the sub-pre-encoding codeword of leakage apart from the channel estimating code word of maximum.

12. device according to claim 7, it is characterized in that, also comprise precoding module, be connected to described convolution operation module, be used at described serving BS described expectation coding codeword and the sub-pre-encoding codeword of described leakage being carried out convolution operation, obtain after the described pre-encoding codeword, carry out precoding processing to transmitting according to described pre-encoding codeword.

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