CN101557367A - Method for precoding multi-point limited cooperative multiple-input-multiple-output communication system - Google Patents

Abstract

The invention discloses a method for precoding multi-point limited cooperative multiple-input-multiple-output communication system. The method is based on hybrid channel information which is limitedly cooperatively obtained from each transmitter to all receivers; each transmitter precodes the sending signal of the receivers which are serviced thereby according to the obtained channel information to maximize the energy of the desired signal of each transmitter and minimize interference to the other receivers; the communication system comprises a plurality of transmitters and a plurality of receivers, wherein, each transmitter can transmit desired signal to the receivers simultaneously, while, each receiver can receive the desired signal from one transmitter simultaneously at most, and signals from the other transmitters are taken as interference; and the transmitters are divided into a plurality of clusters which are not interfered with each other, wherein, the transmitters in the same cluster can limitedly cooperate with each other and the transmitters in different clusters can not cooperate with each other. Compared with the prior art, the method better obtains compromising between the communication system and real complexity.

Description

The precoding multi-point limited cooperative multiple-input-multiple-output communication system method

Technical field

The present invention relates to a kind of method for precoding that is applied to wireless communication system, relate to a kind of method for precoding of multi-point limited cooperative multiple-input-multiple-output communication system especially, belong to wireless communication field.

Background technology

(Multiple-Input Multiple-Output, MIMO) communication technology has obtained abundant development to multiple-input and multiple-output, and is acknowledged as one of key technology of effective lifting future wireless systematic function in recent years.According to information-theoretical result of study, for example: E.Telatar, " Capacity of multi-antenna Gaussian channels; " EuropeanTransactions on Telecommunication, vol.10, no.6, pp.585-595, Nov/Dec.1999, the smaller value in the capacity of point-to-point multi-input multi-output system and the sending and receiving antenna number is the relation of linear growth.Space division multiple access (Space Division Multiple Access, SDMA) technology utilize precoding or beam-forming technology can be on multiplexing a plurality of spaces on identical time slot and the frequency separable user, thereby the volumetric properties that significantly promotes the multi-input multi-output system of point-to-multipoint (sees Q.H.Spencer for details, A.L.Swindlehurst, M.Haardt, " Zero-forcing methods fordownlink spatial multiplexing in multiuser MIMO channels; " IEEE Transactions onSignal Processing, vol.52, no.2, pp.461-471, Feb.2004.).Yet above-mentioned conclusion all is based on the single-shot transmitter system, do not have in theoretical derivation and the algorithm design process to consider that the cochannel from other transmitters disturbs (Co-Channel Interference, CCI).In the cellular radio Communication system of reality, often exist a plurality of transmitters and a plurality of receiver simultaneously, the signal that arbitrary transmitter is launched all can cause interference to the receiver of other transmitter services, and whole system is normally interference-limited.As seen, in multi-multipoint full rate multiplex system, cochannel from other transmitter disturbs the key factor that just becomes restriction MIMO technique elevator system performance (to see S.Catreux for details, P.F.Driessen, L.J.Greenstein, " Simulation results for an interference-limitedmultiple-input multiple-output cellular system; " IEEE Communications Letters, vol.4, no.11, pp.334-336, Nov.2000.).

In non-centralized cellular radio communication network system, though the cochannel between a plurality of receivers of same transmitter service disturbs instantaneous channel condition information (the Channel State Information can utilize each receiver that transmitting terminal obtains, CSI) adopt the pre-coding scheme of traditional point-to-multipoint effectively to suppress, but still can cause certain interference the receiver of other transmitter services.Therefore, the precoding technique of traditional point-to-multipoint is applied directly to is difficult to obtain preferable performance in the multi-multipoint cellular system.For the cochannel that suppresses effectively in the multi-multipoint full rate multiplex system disturbs, even this interference is converted into useful signal, network multiple-input and multiple-output (Network MIMO) technology based on the complete collaborative process of a plurality of transmitters has obtained extensive concern in recent years.If regard a plurality of co-operating transmitters as a more massive virtual transmitter, comprise dirty paper code (dirty paper coding so, DPC) and based on the pre-coding scheme of different criterions can be applied in the multi-multipoint multi-input multi-output system, unique different be that the constraint of transmitting power no longer is a total power constraint, but the power constraint of each transmitter.Though the cochannel that the network MIMO technology of handling based on multipoint cooperative can effectively suppress even eliminate in the multi-multipoint system disturbs, thereby the effective spectrum efficiency of elevator system is a cost but the lifting of this performance is surge with signaling and feedback overhead and computation complexity.Even if by whole system is divided into a plurality of scales less relatively bunch and a plurality of base stations in same bunch between the signaling and the feedback overhead that can correspondingly reduce system of cooperating fully (see A.Papadogiannis for details, D.Gesbert, E.Hardouin, " A dynamic clusteringapproach in wireless networks with multi-cell cooperative processing; " in Proc.IEEEInternational Conference on Communications (ICC), pp.4033-4037, Beijing, China, May2008.), it is still extremely important further to reduce the required overhead of information interaction between feedback of channel information and the base station.

In sum, also exist certain defective during the precoding problem of prior art in solving the multi-multipoint multiplexing multiple-input-multiple-output communication system of full rate, it is less to press for a kind of signaling and feedback overhead, and computation complexity is lower, and has the precoding technique of better performance.

Summary of the invention

Technical problem: at the shortcoming of prior art, it is less to the invention provides a kind of signaling and feedback overhead, and computation complexity is lower, and has the precoding multi-point limited cooperative multiple-input-multiple-output communication system method of better performance.

Technical scheme: the described communication system architecture of embodiments of the invention comprises a plurality of transmitters and a plurality of receiver, wherein a plurality of transmitters are divided into a plurality of mutually disjoint bunch by the cluster-dividing method of static state, each bunch is made up of the contiguous transmitter in a plurality of geographical position, with interactive channel state information partly between a plurality of transmitters in the cluster, thereby realization limited cooperative, and interactive information not between the transmitter in different bunches can't be worked in coordination with.Whole communication system adopts the multiplexing mode of full rate, and promptly each link can use entire available bandwidth simultaneously.Each transmitter can simultaneously send useful signals to a plurality of receivers, and each receiver synchronization can receive useful signal from a transmitter at the most, all is considered as disturbing from the signal of other transmitter.

Embodiments of the invention disclose a kind of precoding multi-point limited cooperative multiple-input-multiple-output communication system method, comprise following steps:

Step 1: adopt static mode that a plurality of transmitters are divided into a plurality of mutually disjoint bunch, each bunch is made up of the contiguous transmitter in a plurality of geographical position;

Step 2: each receiver is estimated the channel response between itself and each transmitter;

Step 3: each receiver feeds back to transmitter for its service with the channel response of estimating, thereby makes each transmitter obtain the instantaneous channel condition information of its each receiver of serving;

Step 4: partial information is mutual with carrying out between the different transmitters in the cluster, realizes limited cooperative;

Step 5: each transmitter obtains it to the statistical information with channel between the receiver of other transmitter service in the cluster by limited cooperative;

Step 6: each transmitter adopt form that a scalar factor is multiplied by a unit matrix to its in other bunch between each receiver the statistical information of channel approach;

Step 7: in itself that each transmitter obtains according to self and the communication system between all receivers the mixed information of channel design the pre-coding matrix of its a plurality of receivers of serving, based on the optimization criterion be: in each receiver desired signal energy of maximization, minimize the interference that the signal of this receiver causes other receiver; Wherein mixed information comprises: the instantaneous channel condition information between this transmitter that is obtained by step 3 and a plurality of receivers of its service, this transmitter that is obtained by step 4 is to the statistical channel state information each receiver of other transmitter service in the cluster, and this transmitter that is obtained by step 6 value of approaching of the statistical information of channel each receiver in other bunch;

Step 8: when each receiver was equipped with an antenna, each receiver can be supported a data flow at most, and the design of precoding vector can be described as following optimization problem:

subject?to ${\left|\right|W_k\left|\right|}_{\mathrm{<figure-callout\; id="2"\; label="F"\; filenames="A20091002483300101.png,A20091002483300132.png"\; state="\{\{state\}\}">F</figure-callout>}}^2=1$

Order $A_k=H_{k,b\left(k\right)}^H{H}_{k,b\left(k\right)}$ With Then this optimization problem can adopt and solve A _kW _k=λ B _kW _kThe algorithm of this generalized eigenvalue problem is solved, and its optimal solution is maximum generalized eigenvalue characteristic of correspondence vector;

Step 9: when each receiver was equipped with many antennas, each receiver can be supported a plurality of data flow simultaneously, not only needed to determine its precoding vector for each data flow, and will realize the optimized distribution of transmitting power on a plurality of data flow this moment:

1.. at first give its a plurality of receivers of serving with the available launch power mean allocation of each transmitter, promptly to arbitrary receiver k ∈ 1 ..., the K} order

2.. next makes the data flowing full emission of each receiver, promptly to arbitrary receiver k ∈ 1 ..., K} makes L _k=rank (H _{K, b (k)});

3.. the available launch power mean allocation with each receiver arrives each data flow once more, and each data flow adopts A _k/ B _kCharacteristic vector in one as its precoding vector, promptly to k ∈ arbitrarily 1 ..., K} and l ∈ 1 ..., L _kOrder: P _{K, l}=P _k/ L _k, $W_k=[{\mathrm{<figure-callout\; id="1"\; label="V"\; filenames="A20091002483300101.png,A20091002483300132.png"\; state="\{\{state\}\}">V</figure-callout>}}_1,...,V_{L_k}];$

4.. adaptively the data fluxion of each receiver is adjusted at last, and again its available launch power is carried out optimized distribution: A on selected data flow, each data flow characteristic of correspondence value and pre-set threshold are compared, select to carry out transfer of data more than or equal to the characteristic value corresponding data flow of this threshold value; After B, data flow are determined, adopt the space water-filling algorithm that each data flow is carried out power division, promptly arbitrary receiver k ∈ 1 ..., the l ∈ of K} 1 ..., L _kEach distribution of flows to power be $P_{k,l}={(\mathrm{\&mu;}-\frac{1}{{\mathrm{\&lambda;}}_l})}^{+}.$

Wherein: max{}-maximization operator clips, () ^HThe conjugate transpose of-matrix or vector, || || _FThe Frobenius norm of-matrix or vector, W _k-receiver k ∈ 1 ..., the pre-coding matrix of K}, the receiver number in the K-communication system, b (k)-the be transmitter of receiver k service, H _{K, b (k)}Channel matrix between-transmitter b (k) and the receiver k, H _{U, b (k)}Channel matrix between-transmitter b (k) and the receiver u, R _{B (k)} ^{Intra-cluster}-transmitter b (k) and with the correlation matrix of channel matrix between the receiver of other transmitter service in the cluster, α I-are used for approaching the correlation matrix of channel matrix between the receiver that each transmitter of transmitter b (k) and other bunch serves, The set that the user of-transmitter b (k) service forms,

The number of users of-transmitter b (k) service, P _{B (k)}The available launch power of-transmitter b (k), P _kThe available launch power of-receiver k, L _kThe maximum supported data fluxions of-receiver k, rank (H _{K, b (k)})-channel matrix H _{K, b (k)}Order, P _{K, l}-receiver k ∈ L ..., the l ∈ of K} 1 ..., L _kThe transmitting power of individual data flow, λ-A _kAnd B _kGeneralized eigenvalue,

L _kIndividual characteristic value characteristic of correspondence vector, (x) ⁺=max{0, x}, λ _l-A _k/ B _kL ∈ 1 ..., L _kIndividual characteristic value characteristic of correspondence vector, μ-satisfy power constraint ∑ _lP _{K, l}≤ P _kThe water filling level.

Beneficial effect: the present invention proposes a kind of precoding multi-point limited cooperative multiple-input-multiple-output communication system method.At first, adopt static mode to carry out sub-clustering in a plurality of transmitters, each bunch is made up of the adjacent a plurality of transmitters in a plurality of geographical position; Secondly, each receiver estimate its with each transmitter between channel response, and will estimate to feed back this and be the transmitter of its service; Then, partial information is mutual with carrying out between a plurality of transmitters in the cluster, thereby realizes limited cooperative, and each transmitter obtains self to the statistical information with channel between the receiver of other transmitter services in the cluster by limited cooperative; In addition, each transmitter adopts form that a scalar factor multiply by a unit matrix to come the statistical information of channel between its receiver of serving to the transmitter in other bunches of approximate evaluation; At last, each transmitter carries out precoding to the mixed information of channel between all receivers to the transmission signal of its a plurality of receivers of serving according to himself that obtains, based on the optimization criterion be: in each receiver desired signal energy of maximization, minimize the interference that the signal of this receiver causes other receivers.The present invention is based on the limited cooperative between a plurality of transmitters, each transmitter has made full use of the mixed channel information that obtains by limited cooperative in the pre-coding scheme design process.Compare with existing complete distributed point-to-multipoint multiple-input and multiple-output precoding technology, the present invention has the cochannel interference capability that suppresses intrinsic in the communication system better, thus the availability of frequency spectrum of elevator system better; Compare with existing precoding technique of cooperating fully based on a plurality of transmitters, the present invention needs lower signaling and feedback overhead, has lower implementation complexity.

Description of drawings

Fig. 1 is that communication system of the present invention is formed structural representation, and M represents the transmitter number in the system among the figure, and C represents the number of clusters that the transmitter in the whole system is divided into, and wherein C is the integer factor of M, and N=M/C represents the transmitter number that comprises in each bunch, N _tRepresent the antenna number that each transmitter is equipped with, N _rRepresent the antenna number that each receiver is equipped with.

Fig. 2 is the flow chart of method for precoding of the present invention, in last module of Fig. 2, each transmitter carries out the pretreating scheme design according to himself that is obtained to the mixed channel information of all receivers, and this module brief note is " pretreating scheme design module ".

Fig. 3 is the specific implementation flow chart of " pre-coding scheme design module " in the flow chart of the present invention shown in Figure 2.

Fig. 4-Figure 12 is that transmitter is with the configuration of receiver different antennae, under the situation of different signal to noise ratios, spectrum efficiency with dried make an uproar than the simulation curve that changes of variation, wherein dried making an uproar than being meant from the signal power of the receiver of other transmitter service and the ratio of noise power.Fig. 4: N _t=2, N _r=1, SNR=5dB; Fig. 5: N _t=2, N _r=1, SNR=10dB; Fig. 6: N _t=2, N _r=1, SNR=15dB; Fig. 7: N _t=4, N _r=2, SNR=5dB; Fig. 8: N _t=4, N _r=2, SNR=10dB; Fig. 9: N _t=4, N _r=2, SNR=15dB; Figure 10: N _t=8, N _r=4, SNR=5dB; Figure 11: N _t=8, N _r=4, SNR=10dB; Figure 12: N _t=8, N _r=4, SNR=15dB.

Embodiment

As shown in Figure 1, multi-point limited cooperative multiple-input-multiple-output communication system of the present invention comprises a plurality of transmitters and a plurality of receiver, wherein each transmitter can send useful signal to a plurality of receivers simultaneously, and each receiver synchronization can receive useful signal from transmitter at the most, all is considered as disturbing from the signal of other transmitter.A plurality of transmitters are divided into a plurality of mutually disjoint bunch by the cluster-dividing method of static state, each bunch is made up of the contiguous transmitter in a plurality of geographical position, with interactive channel state information partly between a plurality of transmitters in the cluster, realize limited cooperative, and interactive information not between the transmitter in different bunches can't be worked in coordination with.Whole communication system adopts the multiplexing mode of full rate, and promptly each link can use entire available bandwidth simultaneously.

As shown in Figure 2, precoding multi-point limited cooperative multiple-input-multiple-output communication system method of the present invention comprises the steps:

(1). adopt static mode that a plurality of transmitters are divided into a plurality of mutually disjoint bunch, each bunch is made up of the contiguous transmitter in a plurality of geographical position;

(2). each receiver is estimated the channel response between itself and each transmitter;

(3). each receiver feeds back to transmitter for its service with the channel response of estimating, thereby makes each transmitter obtain the instantaneous channel condition information of its each receiver of serving;

(4). partial information is mutual with carrying out between the different transmitters in the cluster, realizes limited cooperative;

(5). each transmitter obtains it to the statistical information with channel between the receiver of other transmitter service in the cluster by limited cooperative;

(6). each transmitter adopt form that a scalar factor is multiplied by a unit matrix to its in other bunch between each receiver the statistical information of channel approach;

(7). each transmitter designs the pre-coding matrix of its a plurality of receivers of serving according to the mixed information of channel between himself and all receivers of being obtained, based on the optimization criterion be: in each receiver desired signal energy of maximization, minimize the interference that the signal of this receiver causes other receiver; Wherein mixed information comprises: this transmitter that obtains by (3) and the instantaneous channel condition information between its a plurality of receivers of serving, this transmitter that obtains by (4) to this transmitter that obtains with the statistical channel state information each receiver of other transmitter service in the cluster and by (6) to other bunch in the value of approaching of the statistical information of channel each receiver.

As shown in Figure 3, pre-coding scheme design of the present invention comprises the steps:

(1). when each receiver was equipped with an antenna, each receiver can be supported a data flow at most, and the design of precoding vector can be described as following optimization problem:

subject?to ${\left|\right|W_k\left|\right|}_{\mathrm{<figure-callout\; id="2"\; label="F"\; filenames="A20091002483300101.png,A20091002483300132.png"\; state="\{\{state\}\}">F</figure-callout>}}^2=1$

Order $A_k=H_{k,b\left(k\right)}^H{H}_{k,b\left(k\right)}$ With

Then this optimization problem can adopt and solve A _kW _k=λ B _kW _kThe algorithm of this generalized eigenvalue problem is solved, and its optimal solution is maximum generalized eigenvalue characteristic of correspondence vector;

(2). when each receiver was equipped with many antennas, each receiver can be supported a plurality of data flow simultaneously, not only needed to determine its precoding vector for each data flow, and will realize the optimized distribution of transmitting power on a plurality of data flow this moment:

1. at first give its a plurality of receivers of serving with the available launch power mean allocation of each transmitter, promptly to arbitrary receiver k ∈ 1 ..., the K} order

2. secondly make the data flowing full emission of each receiver, promptly to arbitrary receiver k ∈ 1 ..., K} makes L _k=rank (H _{K, b (k)});

3. once more with the available launch power mean allocation of each receiver to each data flow, each data flow adopts A _k/ B _kCharacteristic vector in one as its precoding vector, promptly to receiver k ∈ arbitrarily 1 ..., K} and corresponding data flow l ∈ thereof 1 ..., L _kOrder: P _{K, l}=P _k/ L _k, $W_k=[{\mathrm{<figure-callout\; id="1"\; label="V"\; filenames="A20091002483300101.png,A20091002483300132.png"\; state="\{\{state\}\}">V</figure-callout>}}_1,...,V_{L_k}];$

4. adaptively the data fluxion of each receiver is adjusted at last, and again its available launch power is carried out optimized distribution on selected data flow, be implemented as follows: A, each data flow characteristic of correspondence value and pre-set threshold are compared, select to carry out transfer of data more than or equal to the characteristic value corresponding data flow of this threshold value; After B, data flow are determined, adopt the space water-filling algorithm that each data flow is carried out power division, promptly arbitrary receiver k ∈ 1 ..., the l ∈ of K} 1 ..., L _kEach distribution of flows to power be $P_{k,l}={(\mathrm{\&mu;}-\frac{1}{{\mathrm{\&lambda;}}_l})}^{+}.$

Wherein: max{}-maximization operator clips, () ^HThe conjugate transpose of-matrix or vector, || || _FThe Frobenius norm of-matrix or vector, W _k-receiver k ∈ 1 ..., the pre-coding matrix of K}, the receiver number in the K-communication system, b (k)-the be transmitter of receiver k service, H _{K, b (k)}Channel matrix between-transmitter b (k) and the receiver k, H _{U, b (k)}Channel matrix between-transmitter b (k) and the receiver u, R _{B (k)} ^{Intra-cluster}-transmitter b (k) and with the correlation matrix of channel matrix between the receiver of other transmitter service in the cluster, α I-are used for approaching the correlation matrix of channel matrix between the receiver that each transmitter of transmitter b (k) and other bunch serves,

The set that the user of-transmitter b (k) service forms,

The number of users of-transmitter b (k) service, P _{B (k)}The available launch power of-transmitter b (k), P _kThe available launch power of-receiver k, L _kThe maximum supported data fluxions of-receiver k, rank (H _{K, b (k)})-channel matrix H _{K, b (k)}Order, P _{K, l}-receiver k ∈ 1 ..., the l ∈ of K} 1 ..., L _kThe transmitting power of individual data flow, λ-A _kAnd B _kGeneralized eigenvalue,

L _kIndividual characteristic value characteristic of correspondence vector, (x) ⁺=max{0, x}, λ _l-A _k/ B _kL ∈ 1 ..., L _kIndividual characteristic value characteristic of correspondence vector, μ-satisfy power constraint ∑ _lP _{K, l}≤ P _kThe water filling level.

Fig. 4-Figure 12 has provided transmitter, the configuration of receiver different antennae, and under the situation of different signal to noise ratios, spectrum efficiency is with the dried simulation curve of making an uproar and changing than variation.As seen, almost performance of the present invention all obviously is better than the ZF (Zero-Forcing of existing pre-coding scheme that only maximizes each receiver desired signal energy and traditional complete distributed point-to-multipoint in all embodiment, ZF) and least mean-square error (Minimum Mean Squared Error, MMSE) pre-coding scheme, especially work as a receipts/antenna more for a long time, and performance gain of the present invention is more obvious.In addition, because the present invention is based on a plurality of transmitter limited cooperatives, and between this limited collaborative a plurality of transmitters that only exist only in each bunch, thereby, compare based on the network MIMO technique of cooperating fully between a plurality of transmitters with existing, signaling and feedback overhead required for the present invention reduce greatly, have lower implementation complexity.

Claims (2)

1. precoding multi-point limited cooperative multiple-input-multiple-output communication system method, it is characterized in that, each transmitter that this method is obtained based on limited cooperative arrives the mixed channel information between all receivers, each transmitter carries out precoding according to the mixed channel information of being obtained to the transmission signal of a plurality of receivers of its service, to maximize the energy of each receiver desired signal, minimize the interference that the transmission signal of this receiver causes other receiver simultaneously; Comprise a plurality of transmitters and a plurality of receiver in the communication system, wherein each transmitter can send useful signal to a plurality of receivers simultaneously, and each receiver can receive useful signal from transmitter at the most at synchronization, all is considered as disturbing from the signal of other transmitter; A plurality of transmitters are divided into a plurality of mutually disjoint bunch by the cluster-dividing method of static state, channel condition information with the receiver that can partly be served separately alternately between a plurality of transmitters in the cluster, thereby the realization limited cooperative, and do not work in coordination with between the transmitter in different bunches; The concrete steps of this method are as follows:

Step 1: adopt static mode that a plurality of transmitters are divided into a plurality of mutually disjoint bunch, each bunch is made up of the contiguous transmitter in a plurality of geographical position;

Step 2: each receiver is estimated the channel response between itself and each transmitter;

Step 3: each receiver feeds back to transmitter for its service with the channel response of estimating, thereby makes each transmitter obtain the instantaneous channel condition information of its each receiver of serving;

Step 4: partial information is mutual with carrying out between the different transmitters in the cluster, realizes limited cooperative;

Step 5: each transmitter obtains it to the statistical information with channel between the receiver of other transmitter service in the cluster by limited cooperative;

Step 6: each transmitter adopt form that a scalar factor is multiplied by a unit matrix to its in other bunch between each receiver the statistical information of channel approach;

Step 7: in itself that each transmitter obtains according to self and the communication system between all receivers the mixed information of channel design the pre-coding matrix of its a plurality of receivers of serving, based on the optimization criterion be: the maximization each receiver desired signal energy in, minimize the interference that this receiver signal causes other receiver in the communication system; Wherein mixed information comprises: the instantaneous channel condition information between this transmitter that is obtained by step 3 and a plurality of receivers of its service, this transmitter that is obtained by step 4 is to the statistical channel state information each receiver of other transmitter service in the cluster, and this transmitter that is obtained by step 6 value of approaching of the statistical information of channel each receiver in other bunch;

Step 8: when each receiver was equipped with an antenna, each receiver can be supported a data flow at most, and the design of precoding vector can be described as following optimization problem:

$\max \left\{\frac{W_k^H{H}_{k,b\left(k\right)}^H{H}_{k,b\left(k\right)}{W}_k}{W_k^H(\underset{u\&Element;u\left(b\left(k\right)\right),u\&NotEqual;k}{\mathrm{\&Sigma;}}{H}_{u,b\left(k\right)}^H{H}_{u,b\left(k\right)}+R_{b\left(k\right)}^{\mathrm{intra}-\mathrm{cluster}}+\mathrm{\&alpha;I})W_k}\right\}$

subject?to ${\left|\right|W_k\left|\right|}_F^2=1$

Order $A_k=H_{k,b\left(k\right)}^H{H}_{k,b\left(k\right)}$ With $B_k=\underset{u\&Element;u\left(b\left(k\right)\right),u\&NotEqual;k}{\mathrm{\&Sigma;}}{H}_{u,b\left(k\right)}^H{H}_{u,b\left(k\right)}+R_{b\left(k\right)}^{\mathrm{intra}-\mathrm{cluster}}+\mathrm{\&alpha;I},$ Then this optimization problem can adopt and solve A _kW _k=λ B _kW _kThe algorithm of this generalized eigenvalue problem is solved, and its optimal solution is maximum generalized eigenvalue characteristic of correspondence vector;

Step 9: when each receiver was equipped with many antennas, each receiver can be supported a plurality of data flow simultaneously, not only needed to determine its precoding vector for each data flow, and will realize the optimized distribution of transmitting power on a plurality of data flow this moment.

2. precoding multi-point limited cooperative multiple-input-multiple-output communication system method according to claim 1 is characterized in that in step 9, and each data flow is determined its precoding vector, and realizes that the optimized distribution method of transmitting power on a plurality of data flow is:

1.. at first give its a plurality of receivers of serving with the available launch power mean allocation of each transmitter, promptly to arbitrary receiver k ∈ 1 ..., K} makes P _k=P _{B (k)}/ | u (b (k)) |;

2.. next makes the data flowing full emission of each receiver, promptly to arbitrary receiver k ∈ 1 ..., K} makes L _k=rank (H _{K, b (k)});

3.. the available launch power mean allocation with each receiver arrives each data flow once more, and each data flow adopts A _k/ B _kCharacteristic vector in one as its precoding vector, promptly to k ∈ arbitrarily 1 ..., K} and l ∈ 1 ..., L _kOrder: P _{K, l}=P _k/ L _k, $W_k=[V_1,...,V_{L_k}];$

4.. adaptively the data fluxion of each receiver is adjusted at last, and again its available launch power is carried out optimized distribution: A on selected data flow, each data flow characteristic of correspondence value and pre-set threshold are compared, select to carry out transfer of data more than or equal to the characteristic value corresponding data flow of this threshold value; After B, data flow are determined, adopt the space water-filling algorithm that each data flow is carried out power division, promptly arbitrary receiver k ∈ 1 ..., the l ∈ of K} 1 ..., L _kEach distribution of flows to power be $P_{k,l}={(\mathrm{\&mu;}-\frac{1}{{\mathrm{\&lambda;}}_l})}^{+};$

Wherein: max{}-maximization operator clips, () ^HThe conjugate transpose of-matrix or vector, || || _FThe Frobenius norm of-matrix or vector, W _k-receiver k ∈ 1 ..., the pre-coding matrix of K}, the receiver number in the K-communication system, b (k)-the be transmitter of receiver k service, H _{K, b (k)}Channel matrix between-transmitter b (k) and the receiver k, H _{U, b (k)}Channel matrix between-transmitter b (k) and the receiver u, R _{B (k)} ^{Int ra-cluster}-transmitter b (k) and with the correlation matrix of channel matrix between the receiver of other transmitter service in the cluster, α I-is used for approaching the correlation matrix of channel matrix between the receiver of transmitter b (k) and each transmitter service of other bunch, the set that the user of u (b (k))-transmitter b (k) service forms, | u (b (k)) | the number of users of-transmitter b (k) service, P _{B (k)}The available launch power of-transmitter b (k), P _kThe available launch power of-receiver k, L _kThe maximum supported data fluxions of-receiver k, rank (H _{K, b (k)})-channel matrix H _{K, b (k)}Order, P _{K, l}-receiver k ∈ 1 ..., the l ∈ of K} 1 ..., L _kThe transmitting power of individual data flow, λ-A _kAnd B _kGeneralized eigenvalue,

L _kIndividual characteristic value characteristic of correspondence vector, (x) ⁺=max{0, x}, λ _l-A _k/ B _kL ∈ 1 ..., L _kIndividual characteristic value characteristic of correspondence vector, μ-satisfy power constraint ∑ _lP _{K, l}≤ P _kThe water filling level.

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