CN103843276A - Method and apparatus for nonlinear joint transmission and reception in wireless communication systems - Google Patents

Abstract

The present invention relates to method and apparatus for joint nonlinear transmission and reception in a multiuser MIMO system. According to an embodiment of the present invention, a method for operating a base station in a multiuser MIMO system in which K active UEs communicate with said base station, the method comprising: performing joint Tomlimson-Harashima precoding on information bearing symbols of said K UEs; performing feed-forward precoding to obtain transmitted signal vectors for said K UEs. The method further comprises: determining the number of transmission layers for each of the K UEs according to a predefined criterion; determining, based on the number of transmission layers for each of the K UEs, feed-forward precoding matrix F and joint Tomlimson-Harashima precoding matrix B by using a generalized triangular decomposition scheme. According to an embodiment of the present invention, there is also provided corresponding devices and communication system.

Description

Be used at the non-linear joint transmission of wireless communication system and the method and apparatus of reception

Technical field

Present invention relates in general to communication system, relate to especially for the non-linear joint transmission at wireless communication system and the method and apparatus of reception.

Background technology

In radio communication, multi-user's multiple-input, multiple-output (MIMO) transmission technology has obtained suitable concern in recent years, and this is because it provides the spectrum efficiency of remarkable enhancing and the ability of link reliability than conventional a single aerial system.It becomes the key technology for third generation partner program (3GPP) standard long-term evolution (LTE), LTE senior (LTE-A) Long Term Evolution.The transmission and being weakened by multithread serious interference due to data streams in parallel time of the performance of mimo system of utilizing spatial reuse.In order to reduce the interference between data streams in parallel, can use the processing to data flow in emitting side, such as precoding processing, and in receiver side processing to received signal, such as equilibrium treatment.

Precoding in emitting side matches transmission and channel.No matter still provide a kind of optional mode in the Nonlinear Processing of receiver side in emitting side, it has provided the possibility of the performance improvement that exceedes linear mode (for example, ZF, least mean-square error).Especially, Tomlinson-Harashima precoding (THP) can obtain significantly more excellent performance than linear predictive coding algorithm as one of nonlinear way.

At J.Liu and W.A.Krzymien one piece is entitled as " A Nonlineaer Joint Transmitter-Receiver Processing Algorithm for the Downlink of Multiuser MIMO System; " (IEEE trans.Veh.Technol., the 54th volume, no.7,2189-2204 page, in July, 2008) document in a kind of non-linear combination launcher-receiver Processing Algorithm is disclosed, by reference the entirety of the document is openly incorporated into this.The document is devoted to a kind of novel nonlinear algorithm based on ZF standard, wherein, at base station place application THP, processes and modulo operation but can apply linear receiver at each travelling carriage place.The geometric mean decomposition (GMD) of the algorithm of the document based on for mimo channel, the number for the transport layer of each subscriber equipment (UE) in mimo channel is fixed to the order for the equivalent channel of each UE.That is to say, on all subchannels of UE from the most by force to the most weak homogenizing that realizes.Given concrete constraint criteria, may not optimize according to the transmission of the system of this algorithm.

Be desirable to provide a kind of improved solution for the non-linear joint communication at wireless communication system, it is adapted to the variation of channel fading and can be optimized according to given standard.

Summary of the invention

In order to solve the problem of prior art, one or more method and apparatus execution modes according to the present invention are proposed to be applied to the down link of multi-user MIMO system/many antennas multipoint cooperative system, wherein, in multi-user MIMO system/many antennas multipoint cooperative system, THP can realize by the help of the Generalized Triangular decomposition (GTD) of the equivalent channel for each UE.

According to an aspect of the present invention, it is a kind of for operate the method for base station at wireless communication system that embodiments of the present invention provide, and movable UE and at least one base station more than one in this wireless communication system communicate.The method comprises: the information carrying symbol to UE is carried out associating THP; Carry out feedforward precoding to obtain the transmission signal vectors for UE.The method also comprises: according to predetermined standard, be identified for the number of the transport layer of each UE; The described number of the transport layer based on for each UE, by using GTD scheme, determine feedforward pre-coding matrix and associating THP matrix.

According to a further aspect in the invention, it is a kind of for operate the method for UE at wireless communication system that embodiments of the present invention provide, and movable UE and at least one base station more than one in this wireless communication system communicate.The method comprises: utilize linear equalization matrix to carry out the signal vector of balanced reception; Carry out mould and decision process based on balanced signal vector.The method also comprises: according to predetermined standard, be identified for the number of the transport layer of UE; The described number of the transport layer based on for UE, by using GTD scheme, determine linear equalization matrix.

According to another aspect of the invention, it is a kind of for operate the device of base station at wireless communication system that embodiments of the present invention provide, and movable UE and at least one base station more than one in this wireless communication system communicate.This device comprises: the device of carrying out associating Tomlimson-Harashima precoding for the information carrying symbol to UE; For carrying out feedforward precoding to obtain the device for the transmission signal vectors of UE.This device also comprises: for according to predetermined standard, be identified for several destination devices of the transport layer of each UE; For the described number of the transport layer based on for each UE, by using the device of GTD scheme, definite feedforward pre-coding matrix and associating Tomlimson-Harashima pre-coding matrix.

According to another aspect of the invention, it is a kind of for operate the device of UE at wireless communication system that embodiments of the present invention provide, and movable UE and at least one base station more than one in this wireless communication system communicate.This device comprises: for utilizing linear equalization matrix to carry out the device of the signal vector of balanced reception; Carry out the device of mould and decision process for the signal vector based on balanced.This device also comprises: for the several destination devices for the transport layer of UE according to predetermined standard; For the described number of the transport layer based on for UE, by using GTD scheme to determine the device of linear equalization matrix.

According to another aspect of the invention, embodiments of the present invention provide the base station in a kind of wireless communication system.This base station comprises: at least one processor; And at least one comprises the memory of computer program code, wherein at least one memory and computer program code are configured to utilize at least one processor to carry out the method for operation base station according to the embodiment of the present invention.

According to another aspect of the invention, embodiments of the present invention provide the subscriber equipment in a kind of wireless communication system.This subscriber equipment comprises: at least one processor; And at least one comprises the memory of computer program code, wherein at least one memory and computer program code are configured to utilize at least one processor to carry out the method for operation subscriber equipment according to the embodiment of the present invention.

According to another aspect of the invention, embodiments of the present invention also provide a kind of wireless communication system, comprise according at least one base station of embodiment of the present invention and multiple subscriber equipment.

Accompanying drawing explanation

In claims, set forth the invention feature that is considered to feature of the present invention.But, reading the following detailed description for example embodiment by reference to accompanying drawing, the present invention, its implementation, other object, feature and advantage are by easy to understand, wherein in the accompanying drawings:

Fig. 1 has schematically shown according to the block diagram of one embodiment of the present invention downlink transmission in wireless communication system;

Fig. 2 has schematically shown according to one embodiment of the present invention for operate the flow chart of the method for base station at wireless communication system;

Fig. 3 has schematically shown according to one embodiment of the present invention for operate the flow chart of the method for UE at wireless communication system;

Fig. 4 has schematically shown according to the block diagram of the base station of one embodiment of the present invention; And

Fig. 5 has schematically shown according to the block diagram of the UE of one embodiment of the present invention.

Embodiment

Hereinafter, each execution mode of the present invention is described with reference to the accompanying drawings.In the following description, show many details to more synthetically understand the present invention.But, be apparent that for those skilled in the art, realize the present invention and can there are these details.Additionally, should be appreciated that, the present invention is not limited to specific implementations presented here.On the contrary, can be considered to realize and put into practice the present invention for any combination in any of following characteristics and element, and no matter whether they relate to different execution modes.Therefore, various aspects, feature, execution mode and advantage be below only for illustrative object, and should not be understood to element or the restriction of claims, unless separately indicated significantly in claims.

Fig. 1 has schematically shown according to the block diagram of one embodiment of the present invention downlink transmission in wireless communication system.

Consider multi-user MIMO system, there is M _tthe base station such as eNB of individual antenna is used nonlinear precoding to K UE signal transmission.K UE has N _kreception antenna, for k=1 ..., K.At the number M of the total transmitting antenna in base station place _tand the number N of the reception antenna of k UE _kshould meet

the signal vector y receiving at k UE place _kprovided by following formula

y _k=H _kx _k+n _k 1)

Wherein H _kthe channel gain matrix of representative to the channel of k UE; n _kit is the additive noise for k UE.

The signal of locating to receive all users can be represented as:

y=Hx+n 2)

Wherein

$y={(y_1^T,y_2^T,...,y_K^T)}^T$

$H={(H_1^T,H_2^T,...,H_K^T)}^T$

$n={(n_1^T,n_2^T,...,n_K^T)}^T$

And, should be appreciated that, can illustrate for example according to the downlink transmission of the multipoint cooperative of 3GPP LTE-advanced standard (CoMP) system with reference to figure 1.CoMP technology is conventionally integrated multiple eNB/ points and is merged and transmit identical or different data messages to identical UE to form collaboration set.By this way, improved the received signal strength of UE, and reduced presence of intercell interference.Suppose perfect cooperation between base station, the downlink transmission of CoMP system can be modeled as the MIMO broadcast channel that utilizes an equivalent base station with multiple antennas.

Consider to utilize many cell mimos system of CoMP, wherein K _tindividual base station utilizes nonlinear precoding jointly to transmit to K UE.Each base station in base station is equipped with n _tindividual antenna and for k=1 ..., k UE of K has N _kindividual reception antenna.Each base station is by backhaul network and central controller exchange of control information.Therefore, this can be modeled as all base stations in cooperation set as having M _t=K _tn _tthe single joint base station of individual antenna.Therefore the signal, receiving at the UE place of CoMP system also can through type 1) and formula 2) expression.

In succinct consideration, term " wireless communication system " is used to refer to any system in the two for multi-user MIMO system and multipoint cooperative system herein, and any can be according to the wireless communication system of the structural modeling in system shown in Fig. 1; Term " base station " can be used to refer to has the single base station of multiple antennas or the Equivalent Modeling base station for cooperative base station in multipoint cooperative system in the multi-user MIMO system of Dai Dan community.

As shown in Figure 1, representative is for the vector of the symbolic vector of the modulation of all UE

be fed to TH precoding module.TH precoding module is by backward square formation B and nonlinear operation symbol MOD _τ() forms, operator MOD _τ() acts on real part and the imaginary part of its input as follows independently:

Wherein τ is relevant to adopted modulating mode; And operator

it is the maximum integer that is no more than z for obtaining.Should be appreciated that, matrix B must be strict lower triangle to allow carrying out data precoding with recursive fashion.After TH precoding, obtain delivery channel signal vector i the element of u obtains by following formula:

$u_i={\mathrm{MOD}}_{\mathrm{\τ}}(s_i-\underset{l=1}{\overset{i-1}{\mathrm{\Σ}}}{\left[B\right]}_{i,l}{u}_{l}k,i=1,\·\·\·,\underset{k=1}{\overset{K}{\mathrm{\Σ}}}{l}_k$

Wherein l _kit is the number of the transport layer of k UE.

By feedforward pre-coding matrix F=[F ₁, F ₂..., F _k], to channel signal vector u feedforward precoding.Can be expressed as from the signal vector of base-station transmission:

$x=\mathrm{Fu}=\underset{k=1}{\overset{K}{\mathrm{\Σ}}}{F}_k{u}_k$

Wherein the channel signal vector u for k UE _kfeedforward pre-coding matrix, l _kit is the number for the transport layer of k UE.

At receiver side place, k UE is by using linear equalization matrix R _kto the signal vector y receiving _kcarry out equilibrium.Signal vector after equilibrium enters mould and judging module to carry out mould and decision process.

In the prior art, for example a piece at J.Liu and W.A.Krzymien is entitled as " A Nonlineaer Joint Transmitter-Receiver Processing Algorithm for the Downlink of Multiuser MIMO System, " (IEEE trans.Veh.Technol., the 54th volume, no.7, 2189-2204 page, in July, 2008) document in, GMD based on mimo channel determines at the feedforward pre-coding matrix F of emitting side and combines Tomlimson-Harashima pre-coding matrix B (being backward square formation) and the linear equalization matrix R at receiver side.The number l of transport layer _kbe fixed to the order for the equivalent channel of UE k.That is to say, on all subchannels of UE from the most by force to the most weak homogenizing that realizes.Given concrete constraint criteria, may not optimize according to the transmission of the system of this algorithm.In this case, given concrete bLock error rate (BLER) can not be optimized the transmission of wireless communication system, and given transmission rate also can not minimize BLER for each UE.

Each execution mode of the present invention is proposed to improve existing scheme of the prior art.According to the embodiment of the present invention, the continuous ZF precoding of piece is used to eliminate in advance part multi-user interference and is convenient to realize TH precoding, and TH precoding realizes by the equivalent channel of the help GTD of to(for) each UE.Based on distributing to the through-put power of each UE and determining the number of the transport layer of distributing to this UE for the singular value of the equivalent channel of this UE.By using GTD scheme, number based on for the definite transport layer of each UE, determine in the feedforward pre-coding matrix F of emitting side and associating THP matrix B with at the linear equalization matrix R of receiver side.

Fig. 2 has schematically shown according to one embodiment of the present invention for operate the flow chart of the method for base station at wireless communication system.

As shown in Figure 2, at step S200, start according to the processing at the base station place at wireless communication system of one embodiment of the present invention.

At step S210, the channel condition information of the channel based on for from base station to k UE, by determining the feedforward pre-coding matrix F for k UE by the continuous ZF of piece _kfirst order matrix N _k, k=1 ..., K.

The feedforward pre-coding matrix F of k UE _kformed by two-stage, i.e. F _k=N _kt _k, first order matrix N _kwith second level matrix T _k.

First order matrix N _khave as part cascaded channel matrix

the row on kernel basis, as follows:

${\stackrel{\‾}{H}}_j{N}_k=0,\mathrm{forj}\≤k.$

Wherein

and the number M of the total transmitting antenna in base station place _tand the number N of the reception antenna of k UE _kshould meet

for k=1, can suppose

for null matrix, i.e. N ₁do not there is this constraint.

Use the channel condition information from base station to supported multiple users' channel, can be based on the continuous ZF of piece, for example, by using singular value decomposition (SVD) or QR decomposing scheme to obtain first order feedforward pre-coding matrix N _k.

At step S220, by using SVD scheme, to the equivalent channel matrix H of k UE _kn _kdecompose, k=1 ..., K.

Calculate equivalent channel matrix H _kn _ksingular value σ _i(k), and by it with descending sort, wherein H _kbe the channel gain matrix of representative to the channel of k UE, and i is index and the satisfied 1≤i≤S of the singular value of descending _k, S _kequivalent channel matrix H _kn _korder.

At step S230, according to predetermined standard, be identified for the number of the transport layer of k UE, k=1 ..., K.

Base station obtains the equivalent channel matrix H of k UE _kn _ksingular value, equivalent channel matrix H _kn _kphysical channel and first order feedforward pre-coding matrix for this UE are merged.According to predetermined standard, be identified for the number of the transport layer of k UE.

According to an embodiment of the invention, the number l of transport layer _kstandard based on maximum channel throughput and definite, wherein

$l_k\text{=arg}\underset{1\≤n\≤S_k}{\max }n{\log }_2(1+\frac{P_k}{n}\sqrt[n]{\underset{i=1}{\overset{n}{\mathrm{\Π}}}{\mathrm{\σ}}_i^2\left(k\right)})$

Wherein P _kit is the through-put power of distributing to k UE.

According to another embodiment of the present invention, the number l of transport layer _kbased on meeting the standard of desired bLock error rate and definite, wherein

$l_k=\arg \underset{\frac{P_k}{n}\sqrt[n]{{\mathrm{\Π}}_{i=1}^n{\mathrm{\σ}}_i^2\left(k\right)}\≥{\mathrm{\γ}}_k,1\≤n\≤S_k}{\max }n$

Wherein γ _kcorresponding to described desired bLock error rate, for the signal to noise ratio/Signal to Interference plus Noise Ratio of each data flow; P _kit is the through-put power of distributing to k UE.

At step S240, the number of the transport layer of the each UE based on for a described K UE, by using GTD scheme to determine feedforward pre-coding matrix F and associating THP matrix B.

By use GTD scheme as follows to for k UE (k=1 ..., K) equivalent channel matrix H _kn _kdecompose:

$H_k{N}_k=Q_k{J}_k{P}_k^H$

Wherein Q _kand P _kit is half unitary matrice;

J _kbe lower triangular matrix, its diagonal element is provided by following formula:

${\left[J_k\right]}_{i,i}={\stackrel{\‾}{\mathrm{\σ}}}_{k,l_k},\mathrm{fori}=1,\·\·\·,l_k,$

${\left[J_k\right]}_{i,i}={\mathrm{\σ}}_i\left(k\right),\mathrm{fori}=l_k+1,\·\·\·,S_k,$

equivalent channel matrix H _kn _kfront l _kthe geometric mean of individual maximum singular value.

Calculate feedforward pre-coding matrix F by following formula _ksecond level matrix T _k:

$T_k=\sqrt{\frac{P_k}{l_k\mathrm{\Γ}}}{\left[P_k\right]}_{:,1:l_k}$

Wherein P _kbe the through-put power of distributing to k UE, Γ is for the normalized constant of through-put power.

Like this, determine feedforward pre-coding matrix F by following formula:

F=[F ₁，F ₂，…，F _K]

Wherein $F_k=\sqrt{\frac{P_k}{l_k\mathrm{\Γ}}}{N}_k{T}_k=\sqrt{\frac{P_k}{l_k\mathrm{\Γ}}}{N}_k{\left[P_k\right]}_{:,1:l_k}.$

For k the UE of a described K UE, calculate linear equalization matrix R by following formula _k:

$R_k={\mathrm{\Λ}}_k{\left[Q_k\right]}_{:,1:l_k}^H$

Wherein ${\mathrm{\Λ}}_k=\mathrm{diag}{\{{\left[J_k\right]}_{\mathrm{1,1}},\·\·\·,{\left[J_k\right]}_{l_k,l_k}\}}^{-1}.$

Cascade linear equalization matrix R for all K UE can be defined as to R=blockdiag (R ₁, R ₂..., R _k), wherein operator blockdiag (M ₁..., M _k) represent to there is diagonal element M ₁..., M _kblock diagonal matrix.

Finally, determine associating THP matrix B by following formula:

$B={\left[\mathrm{blockdiag}(\sqrt{\frac{P_1}{l_1\mathrm{\Γ}}}{I}_{l_1},\·\·\·,\sqrt{\frac{P_K}{l_K\mathrm{\Γ}}}{I}_{l_K})\right]}^{-1}\mathrm{RHF}-I$

Wherein H is cascaded channel gain matrix, and it is provided by following formula

$H={[H_1^T,H_2^T,\·\·\·,H_K^T]}^T,$

Operator blockdiag (M ₁..., M _k) represent to there is diagonal element M ₁..., M _kblock diagonal matrix,

I is unit matrix.

At step S250, the matrix B based on definite and F, to for all UE1 ..., the symbol of the modulation of K is carried out associating THP and the precoding that feedovers, to obtain the signal vector for the transmission of all K UE.

With reference to Fig. 1, the base station precoding for downlink transmission is discussed, has been omitted the description to it here for the object of simplifying.

At step S260, finish according to the processing at base station in wireless communication system place of embodiment of the present invention.

Although should be noted that not shown in Figure 2ly, described feedforward pre-coding matrix F need to be notified to k UE in base station _kdetermined first order matrix N _k.Utilize first order matrix N _kwith channel gain matrix H _kknowledge, k UE can determine corresponding linear equalization matrix R _kwith the signal vector that equilibrium was received, this is described in detail with reference to Fig. 3.

Fig. 3 has schematically shown according to one embodiment of the present invention for operate the flow chart of the method for UE at wireless communication system.

At step S300, start according to the processing at the UE place in wireless communication system of one embodiment of the present invention.

At step S310, by using SVD scheme, decompose the equivalent channel matrix H of k UE _kn _k.

Receive described feedforward pre-coding matrix F at k UE place from respective base station _kfirst order matrix N _k.It will be rational carrying out following hypothesis: for each UE channel gain matrix during at least one transmission cycle, be fix and be all abundant known for respective base station and k UE.

Calculate equivalent channel matrix H _kn _ksingular value σ _i(k), and by it with descending sort, wherein i be descending singular value index and meet 1≤i≤S _k, S _kequivalent channel matrix H _kn _korder.

At step S320, according to predetermined standard, be identified for the number of the transport layer of k UE.

K UE obtains the equivalent channel matrix H of k UE _kn _ksingular value, equivalent channel matrix H _kn _kphysical channel and first order feedforward pre-coding matrix for this UE are merged.According to predetermined standard, be identified for the number of the transport layer of k UE.

According to an embodiment of the invention, the number l of transport layer _kstandard based on maximum channel throughput and definite, wherein

$l_k\text{=arg}\underset{1\≤n\≤S_k}{\max }n{\log }_2(1+\frac{P_k}{n}\sqrt[n]{\underset{i=1}{\overset{n}{\mathrm{\Π}}}{\mathrm{\σ}}_i^2\left(k\right)})$

Wherein P _kit is the through-put power of distributing to k UE.

According to another embodiment of the present invention, the number l of transport layer _kbased on meeting the standard of desired bLock error rate and definite, wherein

$l_k=\arg \underset{\frac{P_k}{n}\sqrt[n]{{\mathrm{\Π}}_{i=1}^n{\mathrm{\σ}}_i^2\left(k\right)}\≥{\mathrm{\γ}}_k,1\≤n\≤S_k}{\max }n$

Wherein γ _kcorresponding to described desired bLock error rate, for the signal to noise ratio/Signal to Interference plus Noise Ratio of each data flow; P _kit is the through-put power of distributing to k UE.

According to another embodiment of the present invention, the number l of transport layer _kbased on meeting the standard of desired bLock error rate and definite, wherein

$l_k=\arg \underset{\frac{P_k}{n}\sqrt[n]{{\mathrm{\Π}}_{i=1}^n{\mathrm{\σ}}_i^2\left(k\right)}\≥{\mathrm{\γ}}_k,1\≤n\≤S_k}{\max }n$

Wherein γ _kcorresponding to described desired bLock error rate, for the signal to noise ratio/Signal to Interference plus Noise Ratio of each data flow; P _kit is the through-put power of distributing to k UE.

At step S330, the number of the transport layer based on for k UE, by using GTD scheme, determines linear equalization matrix R _k.

By using GTD scheme as follows to the equivalent channel matrix H for k UE _kn _kdecompose:

$H_k{N}_k=Q_k{J}_k{P}_k^H$

Wherein Q _kand P _kit is half unitary matrice;

J _kbe lower triangular matrix, its diagonal element is provided by following formula:

${\left[J_k\right]}_{i,i}={\stackrel{\‾}{\mathrm{\σ}}}_{k,l_k},\mathrm{fori}=1,\·\·\·,l_k,$

${\left[J_k\right]}_{i,i}={\mathrm{\σ}}_i\left(k\right),\mathrm{fori}=l_k+1,\·\·\·,S_k,$

equivalent channel matrix H _kn _kfront l _kthe geometric mean of individual maximum singular value.

Like this, calculate linear equalization matrix R by following formula _k:

$R_k={\mathrm{\Λ}}_k{\left[Q_k\right]}_{:,1:l_k}^H$

Wherein ${\mathrm{\Λ}}_k=\mathrm{diag}{\{{\left[J_k\right]}_{\mathrm{1,1}},\·\·\·,{\left[J_k\right]}_{l_k,l_k}\}}^{-1}.$

At step S340, utilize the linear equalization matrix R calculating _kthe signal vector that k UE place received carries out equilibrium and the signal vector after equilibrium is carried out to mould and decision process.

At step S350, finish according to the processing at k the UE place in wireless communication system of one embodiment of the present invention.

Describe the processing in base station and in UE according to embodiment of the present invention in detail with reference to Fig. 2 and Fig. 3.Should be noted that above description is only all exemplary, is not intended to limit the present invention.In other execution mode of the present invention, it is more or still less or different steps that the method can have, and the numbering of step is only more succinct and more clear for making to describe, rather than the order between conditioning step strictly, and the order of step can from describe different.For example, in some embodiments, above-mentioned one or more optional step can be omitted.The specific implementations of each step can be different from description.Within all these distortion all fall into the spirit and scope of the present invention.

Fig. 4 has schematically shown according to the simplified block diagram of the base station of one embodiment of the present invention.

Base station 400 is suitable for communicating with multiple UE in wireless communication system.As previously mentioned, base station 400 can be the single base station with multiple antennas (for example, eNB) in the community of multi-user MIMO system, or in multipoint cooperative system the Equivalent Modeling base station of each base station of multiple cell coordinations.

Base station 400 comprises data processor (DP) 410, is coupled to/is embedded into the memory (MEM) 420 of DP410, and aerial array 450 is coupled to the applicable RF reflector TX/ receiver RX440 of DP410.RF TX/RX module 440 is for carrying out two-way wireless communication with at least one UE.MEM420 storage program (PROG) 430.

PROG430 is believed to comprise program command, in the time that program command is carried out by DP410, can make base station 400 to operate according to exemplary embodiment of the invention, as method 200 as shown in Figure 2 discussed here.

MEM420 can have and is anyly suitable for the type of local technical environment and can utilizes any applicable data storage technology to realize, as non-limiting example, these data storage technologies are for example memory device, magnetic storage apparatus and system, light storage device and system, read-only storage and the removable memories of based semiconductor.Although only at a MEM shown in base station 400, in base station 400, can there are several physically different memory cells.

DP410 carry out as with reference to figure 1 and the described matrix operation in precoding process of Fig. 2.DP410 can have any type that is suitable for local technical environment, and it can comprise one or more all-purpose computers, special-purpose computer, microprocessor, DSP and the processor based on polycaryon processor framework as non-limiting example.

Fig. 5 has schematically shown according to the simplified block diagram of the UE of one embodiment of the present invention.

Conventionally, the various execution modes of UE500 can include but not limited to cell phone, have wireless communication ability PDA, have wireless communication ability pocket computer, have wireless communication ability image capture device (such as digital camera), there is the game station of wireless communication ability and integrate portable unit or the terminal of the combination of these functions.

UE500 is suitable for communicating with one or more base stations in wireless communication system.Just as previously mentioned, the in the situation that of multi-user MIMO system, in multiple UE, (each UE has individual antenna or multiple antenna (as shown in Figure 5)) communicates with the base station that is equipped with multiple antennas simultaneously; And the in the situation that of coordinated multi-point system, UE500 receives identical/different data message from the collaboration set splice grafting of the base station of some neighbor cells.

UE500 comprises data processor (DP) 510, is coupled to/is embedded into the memory (MEM) 520 of DP510, and aerial array 550 is coupled to the applicable RF reflector TX/ receiver RX540 of DP510.RF TX/RX module 540 is for carrying out two-way wireless communication with at least one base station.MEM520 storage program (PROG) 530.

PROG530 is believed to comprise program command, in the time that program command is carried out by DP510, can make UE500 to operate according to exemplary embodiment of the invention, as method 300 as shown in Figure 3 discussed here.

MEM520 can have and is anyly suitable for the type of local technical environment and can utilizes any applicable data storage technology to realize, as non-limiting example, these data storage technologies are for example memory device, magnetic storage apparatus and system, light storage device and system, read-only storage and the removable memories of based semiconductor.Although only at a MEM shown in UE500, in UE500, can there are several physically different memory cells.

DP510 carry out as with reference to figure 1 and the described matrix operation in precoding process of Fig. 3.DP510 can have any type that is suitable for local technical environment, and it can comprise one or more all-purpose computers, special-purpose computer, microprocessor, DSP and the processor based on polycaryon processor framework as non-limiting example.

Generally speaking, various example embodiment can combine to realize with hardware or special circuit, software, logic or its.For example, some aspects can be implemented in hardware, and other side can be implemented in firmware or can be by the performed software of controller, microcontroller or other computing equipment, although the present invention is not limited to this.Although the various aspects of illustrative embodiments of the present invention can be illustrated and be described as block diagram and signaling diagram, also should understand these frames described herein, device, system, technology or method and can be implemented in hardware, software, firmware, special circuit or logic, common hardware or controller or other computing equipment or its some combination as non-limiting example.

Thus, should be appreciated that at least some aspect of illustrative embodiments of the present invention can realize with various assemblies, such as integrated circuit (IC) chip and module.As known in the field, the design of integrated circuit is supermatic process substantially.

The present invention can also be embodied as computer program, and it comprises can realize all features of method as described herein and can realize the method in the time being loaded in computer system.

Illustrate particularly and illustrated the present invention with reference to optional execution mode.It should be appreciated by those skilled in the art, can carry out various changes in form and details to the present invention, and can not deviate from the spirit and scope of the present invention.

Claims (37)

1. for operate a method for base station at wireless communication system, in described wireless communication system, K movable UE and at least one base station communicate, and described method comprises:

Information carrying symbol to a described K UE is carried out associating Tomlimson-Harashima precoding;

Carry out feedforward precoding to obtain the transmission signal vectors for a described K UE,

Wherein said method also comprises:

Number according to predetermined standard for the transport layer of each UE of a described K UE;

The described number of the transport layer of the each UE based on for a described K UE, by using Generalized Triangular decomposing scheme to determine feedforward pre-coding matrix F and associating Tomlimson-Harashima pre-coding matrix B.

2. method according to claim 1, also comprises:

K the UE in a described K UE:

The channel condition information of the channel based on for to described UE, by determining described feedforward pre-coding matrix F by the continuous ZF of piece _kfirst order matrix N _k;

By using singular value decomposition scheme, calculate equivalent channel matrix H _kn _ksingular value σ _i(k), H wherein _kbe the channel gain matrix of representative to the channel of k UE, and i is index and the satisfied 1≤i≤S of the described singular value of descending _k, S _kdescribed equivalent channel matrix H _kn _korder.

3. method according to claim 2, wherein also comprises for the number of the transport layer of each UE of described UE according to predetermined standard:

K the UE in a described K UE:

Based on the described standard of maximum channel throughput, determine the described number l of transport layer _k, wherein

$l_k\text{=arg}\underset{1\≤n\≤S_k}{\max }n{\log }_2(1+\frac{P_k}{n}\sqrt[n]{\underset{i=1}{\overset{n}{\mathrm{\Π}}}{\mathrm{\σ}}_i^2\left(k\right)})$

Wherein P _kit is the through-put power of distributing to described k UE.

4. method according to claim 2, wherein also comprises for the number of the transport layer of each UE of described UE according to predetermined standard:

K the UE in a described K UE:

Based on the described standard that meets desired bLock error rate, determine the described number l of transport layer _k, wherein

$l_k=\arg \underset{\frac{P_k}{n}\sqrt[n]{{\mathrm{\Π}}_{i=1}^n{\mathrm{\σ}}_i^2\left(k\right)}\≥{\mathrm{\γ}}_k,1\≤n\≤S_k}{\max }n$

Wherein γ _kcorresponding to described desired bLock error rate, for the signal to noise ratio/Signal to Interference plus Noise Ratio of each data flow; P _kit is the through-put power of distributing to described k UE.

5. according to the method described in arbitrary claim in claim 3-4, wherein determine that feedforward pre-coding matrix F and associating Tomlimson-Harashima pre-coding matrix B comprise:

K the UE in a described K UE:

By using described Generalized Triangular decomposing scheme, by described equivalent channel matrix H _kn _kbe decomposed into:

$H_k{N}_k=Q_k{J}_k{P}_k^H$

Wherein Q _kand P _kit is half unitary matrice;

J _kbe lower triangular matrix, described lower triangular matrix has the diagonal element being provided by following formula:

${\left[J_k\right]}_{i,i}={\stackrel{\‾}{\mathrm{\σ}}}_{k,l_k},\mathrm{fori}=1,\·\·\·,l_k,$

${\left[J_k\right]}_{i,i}={\mathrm{\σ}}_i\left(k\right),\mathrm{fori}=l_k+1,\·\·\·,S_k,$

described equivalent channel matrix H _kn _kfront l _kthe geometric mean of individual maximum singular value.

6. method according to claim 5, wherein determine that feedforward pre-coding matrix F further comprises:

Calculate described feedforward pre-coding matrix F by following formula _ksecond level matrix T _k

$T_k=\sqrt{\frac{P_k}{l_k\mathrm{\Γ}}}{\left[P_k\right]}_{:,1:l_k},$

Wherein P _kbe the through-put power of distributing to described k UE, Γ is for the normalized constant of through-put power;

Determine described feedforward pre-coding matrix F by following formula

F=[F ₁，F ₂，…，F _K]

Wherein $F_k=\sqrt{\frac{P_k}{l_k\mathrm{\Γ}}}{N}_k{T}_k=\sqrt{\frac{P_k}{l_k\mathrm{\Γ}}}{N}_k{\left[P_k\right]}_{:,1:l_k}.$

7. method according to claim 6, wherein determine that associating Tomlimson-Harashima pre-coding matrix B comprises:

For k UE in a described K UE, calculate linear equalization matrix R by following formula _k

$R_k={\mathrm{\Λ}}_k{\left[Q_k\right]}_{:,1:l_k}^H$

Wherein ${\mathrm{\Λ}}_k=\mathrm{diag}{\{{\left[J_k\right]}_{\mathrm{1,1}},\·\·\·,{\left[J_k\right]}_{l_k,l_k}\}}^{-1};$

Cascade linear equalization matrix R for all described UE is defined as to R=blockdiag (R ₁, R ₂..., R _k);

Determine described associating Tomlimson-Harashima pre-coding matrix B by following formula

$B={\left[\mathrm{blockdiag}(\sqrt{\frac{P_1}{l_1\mathrm{\Γ}}}{I}_{l_1},\·\·\·,\sqrt{\frac{P_K}{l_K\mathrm{\Γ}}}{I}_{l_K})\right]}^{-1}\mathrm{RHF}-I$

Wherein H is cascaded channel gain matrix, and described cascaded channel gain matrix is provided by following formula

$H={[H_1^T,H_2^T,\·\·\·,H_K^T]}^T,$

Operator blockdiag (M ₁..., M _k) represent to there is diagonal element M ₁..., M _kblock diagonal matrix.

8. method according to claim 2, also comprises:

Notify described feedforward pre-coding matrix F to described k UE _kdetermine described first order matrix N _k.

9. method according to claim 1, wherein said wireless communication system is multi-user MIMO system.

10. method according to claim 1, wherein said wireless communication system is multipoint cooperative system.

11. 1 kinds for operate the method for UE at wireless communication system, and in described wireless communication system, K movable UE and at least one base station communicate, and described method comprises:

K the UE in a described K UE:

Utilize linear equalization matrix R _kcarry out the signal vector of balanced reception;

Described signal vector based on equilibrium is carried out mould and decision process,

Wherein said method also comprises:

Number according to predetermined standard for the transport layer of described k UE;

The described number of the transport layer based on for described k UE, by using Generalized Triangular decomposing scheme to determine described linear equalization matrix R _k.

12. methods according to claim 11, also comprise:

Receive feedforward pre-coding matrix F from eNode B _kfirst order matrix N _k;

By using singular value decomposition scheme, calculate equivalent channel matrix H _kn _ksingular value σ _i(k), H wherein _kbe the channel gain matrix of representative to the channel of described k UE, and i is index and the satisfied 1≤i≤S of the described singular value of descending _k, S _kdescribed equivalent channel matrix H _kn _korder.

13. methods according to claim 12, wherein also comprise for the number of the transport layer of described k UE according to predetermined standard:

Based on the described standard of maximum channel throughput, determine the described number l of transport layer _k, wherein

$l_k\text{=arg}\underset{1\≤n\≤S_k}{\max }n{\log }_2(1+\frac{P_k}{n}\sqrt[n]{\underset{i=1}{\overset{n}{\mathrm{\Π}}}{\mathrm{\σ}}_i^2\left(k\right)})$

Wherein P _kit is the through-put power of distributing to described k UE.

14. methods according to claim 12, wherein also comprise for the number of the transport layer of described k UE according to predetermined standard:

Based on the described standard that meets desired bLock error rate, determine the described number l of transport layer _k, wherein

$l_k=\arg \underset{\frac{P_k}{n}\sqrt[n]{{\mathrm{\Π}}_{i=1}^n{\mathrm{\σ}}_i^2\left(k\right)}\≥{\mathrm{\γ}}_k,1\≤n\≤S_k}{\max }n$

Wherein γ _kcorresponding to described desired bLock error rate, for the signal to noise ratio of each data flow; P _kit is the through-put power of distributing to described k UE.

15. according to the method described in arbitrary claim in claim 13-14, wherein determines described linear equalization matrix R _kcomprise:

By using described Generalized Triangular decomposing scheme, by described equivalent channel matrix H _kn _kbe decomposed into:

$H_k{N}_k=Q_k{J}_k{P}_k^H$

Wherein Q _kand P _kit is half unitary matrice;

J _kbe lower triangular matrix, described lower triangular matrix has the diagonal element being provided by following formula:

${\left[J_k\right]}_{i,i}={\stackrel{\‾}{\mathrm{\σ}}}_{k,l_k},\mathrm{fori}=1,\·\·\·,l_k,$

${\left[J_k\right]}_{i,i}={\mathrm{\σ}}_i\left(k\right),\mathrm{fori}=l_k+1,\·\·\·,S_k,$

described equivalent channel matrix H _kn _kfront l _kthe geometric mean of individual maximum singular value;

Calculate described linear equalization matrix R by following formula _k

$R_k={\mathrm{\Λ}}_k{\left[Q_k\right]}_{:,1:l_k}^H$

Wherein ${\mathrm{\Λ}}_k=\mathrm{diag}{\{{\left[J_k\right]}_{\mathrm{1,1}},\·\·\·,{\left[J_k\right]}_{l_k,l_k}\}}^{-1};$

16. methods according to claim 11, wherein said wireless communication system is multi-user MIMO system.

17. methods according to claim 11, wherein said wireless communication system is multipoint cooperative system.

18. 1 kinds for operate the device of base station at wireless communication system, and in described wireless communication system, K movable UE and at least one base station communicate, and described device comprises:

Carry out the device of associating Tomlimson-Harashima precoding for the information carrying symbol to a described K UE;

For carrying out feedforward precoding to obtain the device for the transmission signal vectors of a described K UE,

Wherein said device also comprises:

For the several destination devices for the transport layer of each UE of a described K UE according to predetermined standard;

Be used for the described number of the transport layer of the each UE based on for a described K UE, by using Generalized Triangular decomposing scheme to determine the device of feedforward pre-coding matrix F and associating Tomlimson-Harashima pre-coding matrix B.

19. devices according to claim 18, also comprise:

For k the UE for a described K UE, the channel condition information of the channel based on for to described UE, by determining described feedforward pre-coding matrix F by the continuous ZF of piece _kfirst order matrix N _kdevice;

For calculating equivalent channel matrix H by use singular value decomposition scheme _kn _ksingular value σ _i(k) device, wherein H _kbe the channel gain matrix of representative to the channel of k UE, and i is index and the satisfied 1≤i≤S of the described singular value of descending _k, S _kdescribed equivalent channel matrix H _kn _korder.

20. devices according to claim 19, wherein for also comprising for several destination devices of the transport layer of each UE of described UE according to predetermined standard:

For k the UE for a described K UE, the described number l of the described standard transport layer based on maximum channel throughput _kdevice, wherein

$l_k\text{=arg}\underset{1\≤n\≤S_k}{\max }n{\log }_2(1+\frac{P_k}{n}\sqrt[n]{\underset{i=1}{\overset{n}{\mathrm{\Π}}}{\mathrm{\σ}}_i^2\left(k\right)})$

Wherein P _kit is the through-put power of distributing to described k UE.

21. devices according to claim 19, wherein for also comprising for several destination devices of the transport layer of each UE of described UE according to predetermined standard:

For for k the UE of a described K UE, based on the described number l of described standard transport layer that meets desired bLock error rate _kdevice, wherein

$l_k=\arg \underset{\frac{P_k}{n}\sqrt[n]{{\mathrm{\Π}}_{i=1}^n{\mathrm{\σ}}_i^2\left(k\right)}\≥{\mathrm{\γ}}_k,1\≤n\≤S_k}{\max }n$

Wherein γ _kbe corresponding to the bLock error rate of described requirement, for the signal to noise ratio/Signal to Interference plus Noise Ratio of each data flow; P _kit is the through-put power of distributing to described k UE.

22. according to the device described in arbitrary claim in claim 20-21, wherein comprises for the device of determining feedforward pre-coding matrix F and associating Tomlimson-Harashima pre-coding matrix B:

For k the UE for a described K UE, by using described Generalized Triangular decomposing scheme to described equivalent channel matrix H _kn _kthe device decomposing, wherein by H _kn _kbe decomposed into:

$H_k{N}_k=Q_k{J}_k{P}_k^H$

Wherein Q _kand P _kit is half unitary matrice;

J _kbe lower triangular matrix, described lower triangular matrix has the diagonal element being provided by following formula:

${\left[J_k\right]}_{i,i}={\stackrel{\‾}{\mathrm{\σ}}}_{k,l_k},\mathrm{fori}=1,\·\·\·,l_k,$

${\left[J_k\right]}_{i,i}={\mathrm{\σ}}_i\left(k\right),\mathrm{fori}=l_k+1,\·\·\·,S_k,$

described equivalent channel matrix H _kn _kfront l _kthe geometric mean of individual maximum singular value.

23. devices according to claim 22, wherein further comprise for the device of determining feedforward pre-coding matrix F:

For calculating described feedforward pre-coding matrix F by following formula _ksecond level matrix T _kdevice:

$T_k=\sqrt{\frac{P_k}{l_k\mathrm{\Γ}}}{\left[P_k\right]}_{:,1:l_k},$

Wherein P _kbe the through-put power of distributing to described k UE, Γ is for the normalized constant of through-put power;

For determine the device of described feedforward pre-coding matrix F by following formula:

F=[F ₁，F ₂，…，F _K]，

Wherein $F_k=\sqrt{\frac{P_k}{l_k\mathrm{\Γ}}}{N}_k{T}_k=\sqrt{\frac{P_k}{l_k\mathrm{\Γ}}}{N}_k{\left[P_k\right]}_{:,1:l_k}.$

24. devices according to claim 23, wherein comprise for the device of determining associating Tomlimson-Harashima pre-coding matrix B:

Device for following operation:

Calculate linear equalization matrix R for k UE in a described K UE by following formula _k

$R_k={\mathrm{\Λ}}_k{\left[Q_k\right]}_{:,1:l_k}^H$

Wherein ${\mathrm{\Λ}}_k=\mathrm{diag}{\{{\left[J_k\right]}_{\mathrm{1,1}},\·\·\·,{\left[J_k\right]}_{l_k,l_k}\}}^{-1};$

Cascade linear equalization matrix R for all described UE is defined as

R=blockdiag(R ₁，R ₂，…，R _K)；

Determine described associating Tomlimson-Harashima pre-coding matrix B by following formula

$B={\left[\mathrm{blockdiag}(\sqrt{\frac{P_1}{l_1\mathrm{\Γ}}}{I}_{l_1},\·\·\·,\sqrt{\frac{P_K}{l_K\mathrm{\Γ}}}{I}_{l_K})\right]}^{-1}\mathrm{RHF}-I$

Wherein H is cascaded channel gain matrix, and described cascaded channel gain matrix is provided by following formula

$H={[H_1^T,H_2^T,\·\·\·,H_K^T]}^T,$

Operator blockdiag (M ₁..., M _k) represent to there is diagonal element M ₁..., M _kblock diagonal matrix.

25. devices according to claim 19, also comprise:

For notifying described feedforward pre-coding matrix F to described k UE _kdetermine described first order matrix N _kdevice.

26. devices according to claim 18, wherein said wireless communication system is multi-user MIMO system.

27. devices according to claim 18, wherein said wireless communication system is multipoint cooperative system.

28. 1 kinds for operate the device of UE at wireless communication system, and in described wireless communication system, K movable UE and at least one base station communicate, and described device comprises:

For k the UE for a described K UE, utilize linear equalization matrix R _kcarry out the device of the signal vector of balanced reception;

For carry out the device of mould and decision process based on the described signal vector of equilibrium,

Wherein said device also comprises:

For the several destination devices for the transport layer of described k UE according to predetermined standard;

For the described number of the transport layer based on for described k UE, by using Generalized Triangular decomposing scheme to determine described linear equalization matrix R _kdevice.

29. devices according to claim 28, also comprise:

For receive feedforward pre-coding matrix F from eNode B _kfirst order matrix N _kdevice;

For calculating equivalent channel matrix H by use singular value decomposition scheme _kn _ksingular value σ _i(k) device, wherein H _kbe the channel gain matrix of representative to the channel of described k UE, and i is index and the satisfied 1≤i≤S of the described singular value of descending _k, S _kdescribed equivalent channel matrix H _kn _korder.

30. devices according to claim 29, wherein for also comprising for several destination devices of the transport layer of described k UE according to predetermined standard:

For the described number l of the described standard transport layer based on maximum channel throughput _kdevice, wherein

$l_k\text{=arg}\underset{1\≤n\≤S_k}{\max }n{\log }_2(1+\frac{P_k}{n}\sqrt[n]{\underset{i=1}{\overset{n}{\mathrm{\Π}}}{\mathrm{\σ}}_i^2\left(k\right)})$

Wherein P _kit is the through-put power of distributing to described k UE.

31. devices according to claim 29, wherein for also comprising for several destination devices of the transport layer of described k UE according to predetermined standard:

For the described number l of described standard transport layer based on meeting desired bLock error rate _kdevice, wherein

$l_k=\arg \underset{\frac{P_k}{n}\sqrt[n]{{\mathrm{\Π}}_{i=1}^n{\mathrm{\σ}}_i^2\left(k\right)}\≥{\mathrm{\γ}}_k,1\≤n\≤S_k}{\max }n$

Wherein γ _kcorresponding to described desired bLock error rate, for the signal to noise ratio of each data flow; P _kit is the through-put power of distributing to described k UE.

32. according to the device described in arbitrary claim in claim 30-31, wherein for determining described linear equalization matrix R _kdevice comprise:

Be used for by using described Generalized Triangular decomposing scheme to decompose described equivalent channel matrix H _kn _kdevice, wherein by H _kn _kbe decomposed into

$H_k{N}_k=Q_k{J}_k{P}_k^H$

Wherein Q _kand P _kit is half unitary matrice;

J _kbe lower triangular matrix, described lower triangular matrix has the diagonal element being provided by following formula:

${\left[J_k\right]}_{i,i}={\stackrel{\‾}{\mathrm{\σ}}}_{k,l_k},\mathrm{fori}=1,\·\·\·,l_k,$

${\left[J_k\right]}_{i,i}={\mathrm{\σ}}_i\left(k\right),\mathrm{fori}=l_k+1,\·\·\·,S_k,$

described equivalent channel matrix H _kn _kfront l _kthe geometric mean of individual maximum singular value;

For calculating described linear equalization matrix R by following formula _kdevice

$R_k={\mathrm{\Λ}}_k{\left[Q_k\right]}_{:,1:l_k}^H.$

Wherein ${\mathrm{\Λ}}_k=\mathrm{diag}{\{{\left[J_k\right]}_{\mathrm{1,1}},\·\·\·,{\left[J_k\right]}_{l_k,l_k}\}}^{-1}.$

33. devices according to claim 28, wherein said wireless communication system is multi-user MIMO system.

34. devices according to claim 28, wherein said wireless communication system is multipoint cooperative system.

Base station in 35. 1 kinds of wireless communication systems, comprising:

At least one processor; And

Comprise at least one memory of computer program code,

Wherein said at least one memory and described computer program code are configured to utilize described at least one processor to carry out according to the method described in arbitrary claim in claim 1-10.

Subscriber equipment in 36. 1 kinds of wireless communication systems, comprising:

At least one processor; And

Comprise at least one memory of computer program code,

Wherein said at least one memory and described computer program code are configured to utilize described at least one processor to carry out according to the method described in arbitrary claim in claim 11-17.

37. 1 kinds of wireless communication systems, comprise at least one base station according to claim 35 and at least one subscriber equipment according to claim 36.

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