CN103580744A - Precode generating method and device for inter-cell multi-antenna cooperative system - Google Patents

Abstract

The invention discloses a method for generating a precoding of an inter-cell multi-antenna cooperative system. The method includes: the cooperative execution base station calculates the interference null space of each cooperation initiating base station and performs combined SVD decomposition, and picks out from the V matrix obtained after decomposition The vectors corresponding to the first r large singular values in the singular value matrix form a vector space S, and the vectors in S are screened, and the vector v _k in S after screening is multiplied by the corresponding singular value σ _k to obtain the precoding space A , the cooperative execution base station projects each vector p _i corresponding to the PMI of the station to the precoding space A to obtain the precoding vector _{w i} . condition, it is confirmed that the precoding vector w _i is valid. The precoding vector generated by the present invention can make the cooperative base station meet the requirement of restraining each channel of interference, and improve the accuracy of precoding. The invention also discloses a precoding generation device of an inter-cell multi-antenna cooperation system.

Description

Pre-coding generation method and device for inter-cell multi-antenna cooperation system

Technical Field

The present invention relates to the field of wireless communication technologies, and in particular, to a method and an apparatus for generating a precoding for an inter-cell multi-antenna cooperative system.

Background

As a standard of the fourth generation communication system (4G), IMT-Advanced puts higher demands on the performance of the system, especially on the frequency efficiency of uplink and downlink. Coordinated multi-point transmission/reception (COMP) is a technology for increasing transmission coverage, improving cell edge service quality and throughput, and improving system throughput, and is an important technology for improving system spectrum utilization. So-called coordinated multipoint transmission, i.e. a transmission where multiple base stations are coordinated, serves one or more user terminals (UEs).

The COMP defined by 3GPP includes 2 scenarios, one is multipoint coordinated scheduling, that is, interference between transmission signals of each cell is coordinated by interacting scheduling information between adjacent nodes; the other is multipoint joint processing, that is, a plurality of cooperative nodes jointly provide service for a target user through shared data, channel state information csi (channel configuration information), scheduling information and the like.

At present, a COMP precoding generation method is based on terminal codebook feedback, then cooperation is performed among base stations, the cooperative base stations put the interacted codebooks together to form a matrix, then SVD decomposition is performed, and by taking UE feedback WCI (Worst code index) as an example, a vector corresponding to a minimum singular value is taken as precoding according to the singular value. In the existing precoding generation method, joint decomposition of the codebook can only ensure interference and minimum, and cannot ensure that the interference to each base station needing cooperation is reduced. On the other hand, the error is large when generating the precoding.

Therefore, the existing COMP precoding generation method needs to be improved.

Disclosure of Invention

The technical problem to be solved by the present invention is to provide a method and an apparatus for generating precoding for an inter-cell multi-antenna cooperative system, which can accurately generate precoding, so that the suppression of the cooperative base station to each channel of interference can meet the requirement.

In order to solve the above technical problem, the present invention provides a precoding generation method for an inter-cell multi-antenna cooperative system, including:

the cooperative execution base station calculates interference null space of each cooperative initiation base station according to interference code word indication information sent by each cooperative initiation base station; combining interference null spaces of all cooperative initiating base stations, carrying out SVD on the combined null spaces, and obtaining a U matrix, a singular value matrix and a V matrix after decomposition; wherein the V matrix corresponds toOf the matrix of singular values of_jSorting according to the numerical value from large to small;

picking out vectors corresponding to the first r large singular values in the singular value matrix from the V matrix to form a vector space S; screening the vectors in the vector space S to screen out the vectors which do not meet the interference requirement, and screening the vectors v in the vector space S_kWith corresponding singular value σ_kMultiplying to obtain precoding space A, A ═ sigma [ sigma ]₁*v₁，σ₂*v₂，...，σ_r*v_t](ii) a The ratio of the accumulated sum of the first r large singular values of the singular value matrix to the sum of all singular values of the singular value matrix is greater than or equal to a threshold value a, and a is greater than 0 and less than 1; t is less than or equal to r, and t is the total number of vectors contained in the precoding space A;

the cooperative execution base station indicates each vector p corresponding to the PMI of the precoding matrix of the base station_iProjecting the pre-coding space A to obtain a pre-coding vector w_i(ii) a I is more than or equal to 1 and less than or equal to l, and l is the total number of vectors corresponding to the PMI;

e.g. precoding vector w_iIf the cooperation condition of the station for performing coordinated multi-point transmission COMP is met, the precoding vector w is confirmed_iIs effective.

Further, the interference code word indication information includes worst interference code word indication WCI or best interference code word indication BCI; the worst interference codeword indication is used to indicate a maximum interference direction of the cooperative initiating base station, and the best interference codeword indication is used to indicate a minimum interference direction of the cooperative initiating base station.

Further, if the cooperative execution base station receives a worst interference codeword indication sent by the cooperative initiation base station, calculating an interference null space according to an interference maximum vector space corresponding to the worst interference codeword indication, and taking the calculated interference null space as the interference null space of the cooperative initiation base station; and if the cooperation executing base station receives the best interference code word indication sent by the cooperation initiating base station, taking the vector space corresponding to the best interference code word indication as the interference null space of the cooperation initiating base station.

Further, screening out vectors that do not meet interference requirements, comprising:

each vector v in the vector space S_kObtaining a vector v 'after projecting the corresponding vector space to each interference code word'_kjCalculating post-projection vector v'_kjNorm of (d) and vector v before projection_kIs the ratio f of the norm of_kj(ii) a J is more than or equal to 1 and less than or equal to n, and n is the total number of the base stations which initiate the cooperation request to the cooperation execution base station;

indicating WCI when interference code word indicates worst interference code word_iWhen, e.g. the ratio f_kjGreater than or equal to the first threshold value a1, the vector v is filtered out_k(ii) a BCI is indicated when interference code word is indicated as best interference code word_iWhen, e.g. the ratio f_kjLess than or equal to the second threshold value a2, the vector v is filtered out_k(ii) a Wherein a1 is more than 0 and less than 1, and a2 is more than 0 and less than 1.

Further, screening out vectors that do not meet interference requirements, comprising:

each vector v in the vector space S_kObtaining a vector v 'after projecting the corresponding vector space to each interference code word'_kjCalculating post-projection vector v'_kjNorm of (d) and vector v before projection_kIs the ratio f of the norm of_kj(ii) a J is more than or equal to 1 and less than or equal to n, and n is the total number of the base stations which initiate the cooperation request to the cooperation execution base station;

each vector p corresponding to precoding matrix indicator PMI_sObtaining a vector p 'after the vector space projection corresponding to each interference code word is indicated'_siCalculating post-projection vector p'_siNorm of (d) and vector p before projection_sIs the ratio f of the norm of_si(ii) a I is more than or equal to 1 and less than or equal to n, and n is the total number of the base stations which initiate the cooperation request to the cooperation execution base station;

indicating WCI when interference code word indicates worst interference code word_iWhen, e.g. the ratio f_kjGreater than or equal to the ratiof_siThe minimum value of (d), then screen out the vector v_k(ii) a BCI is indicated when interference code word is indicated as best interference code word_iWhen, e.g. the ratio f_kjIs less than or equal to the ratio f_siThe maximum value of (d), then the vector v is screened out_k。

Further, the cooperation condition for the local station to perform COMP includes one or more of the following conditions:

a) the energy self-loss of the station meets the requirements, and comprises the following steps:

calculating the precoding vector w of the station_iVector p corresponding to PMI when transmitting in the indicated direction_iEnergy component L in the indicated direction_i，L_i＝SINR*f_i ²(ii) a Wherein,' is a vector inner product symbol, ' | A | ' is a vector A is subjected to modulo operation, and SINR is the signal to interference plus noise ratio of a terminal under the station;

such as L_iIf the energy threshold value is greater than or equal to a5, the precoding vector w is confirmed_iThe method is effective; wherein a5 is more than 0;

b) precoding vector w_iCompared with the precoding matrix PMI, the interference to the neighbor cell is lower, including:

precoding vector w_iObtaining a vector w 'after the vector space corresponding to each interference code word is indicated to be projected'_ijCalculating post-projection vector w'_ijNorm of (d); j is more than or equal to 1 and less than or equal to n, and n is the total number of the base stations which initiate the cooperation request to the cooperation execution base station;

vector p corresponding to precoding matrix indicator PMI_iObtaining a vector p 'after the vector space projection corresponding to each interference code word is indicated'_ijCalculating post-projection vector p'_ijNorm of (d); j is more than or equal to 1 and less than or equal to n, and n is the total number of the base stations which initiate the cooperation request to the cooperation execution base station;

indicating WCI when interference code word indicates worst interference code word_iJust like the vector w 'after projection'_ijNorm of (2) and post-projection vector p'_ijIs less than or equal to a third threshold a3, the precoding vector w is confirmed_iIn the WCI_iThe interference on the corresponding adjacent cell is smaller than that of the PMI; wherein a3 is more than 0 and less than 1;

BCI is indicated when interference code word is indicated as best interference code word_iJust like the vector w 'after projection'_ijNorm of (2) and post-projection vector p'_ijIs greater than or equal to a fourth threshold a4, the precoding vector w is confirmed_iThe interference of the PMI on the adjacent cell corresponding to the BCI is smaller than that of the PMI; 0 < a4 < 1;

for any precoding vector w_iIf the interference on all the adjacent regions is less than the interference of PMI, confirming the precoding vector w_iOtherwise, confirming the precoding vector w_iAnd (4) invalidation.

In order to solve the above technical problem, the present invention further provides a precoding generation apparatus for an inter-cell multi-antenna cooperative system, including:

the interference null space processing module is used for the cooperative execution base station to calculate the interference null space of each cooperative initiation base station according to the interference code word indication information sent by each cooperative initiation base station; combining interference null spaces of all cooperative initiating base stations, carrying out SVD on the combined null spaces, and obtaining a U matrix, a singular value matrix and a V matrix after decomposition; wherein, the singular value sigma in the singular value matrix corresponding to the V matrix_jSorting according to the numerical value from large to small;

the pre-coding space generation module is used for picking out vectors corresponding to the first r large singular values in the singular value matrix from the V matrix to form a vector space S; screening the vectors in the vector space S to screen out the vectors which do not meet the interference requirement, and screening the vectors v in the vector space S_kWith corresponding singular value σ_kMultiplying to obtain precoding space A, A ═ sigma [ sigma ]₁*v₁，σ₂*v₂，...，σ_r*v_t](ii) a The ratio of the accumulated sum of the first r large singular values of the singular value matrix to the sum of all singular values of the singular value matrix is greater than or equal to a threshold value a, and a is greater than 0 and less than 1; t is less than or equal to r, and t is the total number of vectors contained in the precoding space A;

a precoding vector generation module, configured to cooperate with the execution base station to indicate each vector p corresponding to the PMI of the precoding matrix of the base station_iProjecting the pre-coding space A to obtain a pre-coding vector w_i(ii) a I is more than or equal to 1 and less than or equal to l, and l is the total number of vectors corresponding to the PMI;

precoding vector checking module for precoding vectors w_iIf the cooperation condition of the station for performing coordinated multi-point transmission COMP is met, the precoding vector w is confirmed_iIs effective.

Further, the interference code word indication information includes worst interference code word indication WCI or best interference code word indication BCI; the worst interference codeword indication is used to indicate a maximum interference direction of the cooperative initiating base station, and the best interference codeword indication is used to indicate a minimum interference direction of the cooperative initiating base station.

Further, if the cooperative execution base station receives a worst interference codeword indication sent by the cooperative initiation base station, calculating an interference null space according to an interference maximum vector space corresponding to the worst interference codeword indication, and taking the calculated interference null space as the interference null space of the cooperative initiation base station; and if the cooperation executing base station receives the best interference code word indication sent by the cooperation initiating base station, taking the vector space corresponding to the best interference code word indication as the interference null space of the cooperation initiating base station.

Further, screening out vectors that do not meet interference requirements, comprising:

each vector v in the vector space S_kObtaining a vector v 'after projecting the corresponding vector space to each interference code word'_kjCalculating post-projection vector v'_kjNorm and projection ofVector v of the front_kIs the ratio f of the norm of_kj(ii) a J is more than or equal to 1 and less than or equal to n, and n is the total number of the base stations which initiate the cooperation request to the cooperation execution base station;

indicating WCI when interference code word indicates worst interference code word_iWhen, e.g. the ratio f_kjGreater than or equal to the first threshold value a1, the vector v is filtered out_k(ii) a BCI is indicated when interference code word is indicated as best interference code word_iWhen, e.g. the ratio f_kjLess than or equal to the second threshold value a2, the vector v is filtered out_k(ii) a Wherein a1 is more than 0 and less than 1, and a2 is more than 0 and less than 1.

Further, screening out vectors that do not meet interference requirements, comprising:

each vector v in the vector space S_kObtaining a vector v 'after projecting the corresponding vector space to each interference code word'_kjCalculating post-projection vector v'_kjNorm of (d) and vector v before projection_kIs the ratio f of the norm of_kj(ii) a J is more than or equal to 1 and less than or equal to n, and n is the total number of the base stations which initiate the cooperation request to the cooperation execution base station;

each vector p corresponding to precoding matrix indicator PMI_sObtaining a vector p 'after the vector space projection corresponding to each interference code word is indicated'_siCalculating post-projection vector p'_siNorm of (d) and vector p before projection_sIs the ratio f of the norm of_si(ii) a I is more than or equal to 1 and less than or equal to n, and n is the total number of the base stations which initiate the cooperation request to the cooperation execution base station;

indicating WCI when interference code word indicates worst interference code word_iWhen, e.g. the ratio f_kjIs greater than or equal to the ratio f_siThe minimum value of (d), then screen out the vector v_k(ii) a BCI is indicated when interference code word is indicated as best interference code word_iWhen, e.g. the ratio f_kjIs less than or equal to the ratio f_siThe maximum value of (d), then the vector v is screened out_k。

Further, the cooperation condition for the local station to perform COMP includes one or more of the following conditions:

a) the energy self-loss of the station meets the requirements, and comprises the following steps:

calculating the precoding vector w of the station_iVector p corresponding to PMI when transmitting in the indicated direction_iEnergy component L in the indicated direction_i，L_i＝SINR*f_i ²(ii) a Wherein,' is a vector inner product symbol, ' | A | ' is a vector A is subjected to modulo operation, and SINR is the signal to interference plus noise ratio of a terminal under the station;

such as L_iIf the energy threshold value is greater than or equal to a5, the precoding vector w is confirmed_iThe method is effective; wherein a5 is more than 0;

b) precoding vector w_iCompared with the precoding matrix PMI, the interference to the neighbor cell is lower, including:

precoding vector w_iObtaining a vector w 'after the vector space corresponding to each interference code word is indicated to be projected'_ijCalculating post-projection vector w'_ijNorm of (d); j is more than or equal to 1 and less than or equal to n, and n is the total number of the base stations which initiate the cooperation request to the cooperation execution base station;

vector p corresponding to precoding matrix indicator PMI_iObtaining a vector p 'after the vector space projection corresponding to each interference code word is indicated'_ijCalculating post-projection vector p'_ijNorm of (d); j is more than or equal to 1 and less than or equal to n, and n is the total number of the base stations which initiate the cooperation request to the cooperation execution base station;

indicating WCI when interference code word indicates worst interference code word_iJust like the vector w 'after projection'_ijNorm of (2) and post-projection vector p'_ijIs less than or equal to a third threshold a3, the precoding vector w is confirmed_iIn the WCI_iThe interference on the corresponding adjacent cell is smaller than that of the PMI; wherein a3 is more than 0 and less than 1;

BCI is indicated when interference code word is indicated as best interference code word_iJust like the vector w 'after projection'_ijNorm of (2) and post-projection vector p'_ijIs greater than or equal to a fourth threshold a4, the precoding vector w is confirmed_iThe interference of the PMI on the adjacent cell corresponding to the BCI is smaller than that of the PMI; 0 < a4 < 1;

for any precoding vector w_iIf the interference on all the adjacent regions is less than the interference of PMI, confirming the precoding vector w_iOtherwise, confirming the precoding vector w_iAnd (4) invalidation.

Compared with the prior art, the precoding generation method and device for the inter-cell multi-antenna cooperation system provided by the invention have the advantages that the cooperation base stations calculate the interference null space of each cooperation initiating base station and carry out combined SVD decomposition, vectors corresponding to the first r large singular values in a singular value matrix are selected from a V matrix obtained after decomposition to form a vector space S, the vectors in the S are screened, the precoding space formed by the screened vectors generates precoding vectors and checks whether the precoding vectors meet the COMP cooperation requirement or not, and the checked precoding vectors are confirmed to be effective. The precoding vector generated by the invention can enable the cooperative base station to meet the requirement on the suppression of each path of interference, and improves the accuracy of precoding.

Drawings

Fig. 1 is a flowchart of a precoding generation method of an inter-cell multi-antenna cooperative system according to an embodiment of the present invention.

Fig. 2 is a schematic diagram of an inter-cell multi-antenna cooperative system in an application example of the present invention.

Fig. 3 is a schematic structural diagram of a precoding generation apparatus of an inter-cell multi-antenna cooperative system according to an embodiment of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be noted that the embodiments and features of the embodiments in the present application may be arbitrarily combined with each other without conflict.

As shown in fig. 1, an embodiment of the present invention provides a precoding generation method for an inter-cell multi-antenna cooperative system, where the method includes:

s10, the cooperative execution base station calculates the interference null space of each cooperative initiation base station according to the interference code word indication information sent by each cooperative initiation base station; combining interference null spaces of all cooperative initiating base stations, carrying out SVD on the combined null spaces, and obtaining a U matrix, a singular value matrix and a V matrix after decomposition; wherein, the singular value sigma in the singular value matrix corresponding to the V matrix_jSorting according to the numerical value from large to small, wherein V is [ V ═ V₁，v₂，...，v_m]J is more than or equal to 1 and less than or equal to m, and m is the total number of singular values contained in the singular value matrix;

s20, picking out vectors corresponding to the first r large singular values in the singular value matrix from the V matrix to form a vector space S; screening the vectors in the vector space S to screen out the vectors which do not meet the interference requirement, and screening the vectors v in the vector space S_kWith corresponding singular value σ_kMultiplying to obtain precoding space A, A ═ sigma [ sigma ]₁*v₁，σ₂*v₂，...，σ_r*v_t](ii) a Wherein the ratio of the cumulative sum of the first r large singular values of the singular value matrix to the sum of all singular values of the singular value matrix is greater than or equal to a threshold a, i.e.,

a is more than 0 and less than 1; t is less than or equal to r, and t is the total number of vectors contained in the precoding space A;

s30, the cooperation execution base station indicates each vector p corresponding to PMI of precoding matrix of the base station_iTo the precodingSpace A is projected to obtain a precoding vector w_i(ii) a I is more than or equal to 1 and less than or equal to l, and l is the total number of vectors corresponding to the PMI;

s40, e.g. precoding vector w_iIf the cooperation condition of the station for performing coordinated multi-point transmission COMP is met, the precoding vector w is confirmed_iIs effective.

Step S10 further includes the following features:

the interference code word indication information comprises worst interference code word indication or best interference code word indication; the Worst interference Codeword indication (WCI) is used to indicate the maximum interference direction of the cooperative initiating base station, and the Best interference Codeword indication (Best code Index, BCI) is used to indicate the minimum interference direction of the cooperative initiating base station.

If the cooperation execution base station receives the worst interference code word indication sent by the cooperation initiating base station, calculating an interference null space according to the interference maximum vector space corresponding to the worst interference code word indication, and taking the calculated interference null space as the interference null space of the cooperation initiating base station;

if the cooperative execution base station receives a best interference code word indication sent by the cooperative initiation base station, taking a vector space corresponding to the best interference code word indication as an interference null space of the cooperative initiation base station;

step S20 further includes the following features:

wherein, screening out vectors that do not meet interference requirements comprises:

each vector v in the vector space S_kObtaining a vector v 'after projecting the corresponding vector space to each interference code word'_kjCalculating post-projection vector v'_kjNorm of (d) and vector v before projection_kIs the ratio f of the norm of_kj(ii) a J is more than or equal to 1 and less than or equal to n, and n is the total number of the base stations which initiate the cooperation request to the cooperation execution base station;

when the interference code word indicates the worst interferenceCodeword indication WCI_iWhen, e.g. the ratio f_kjGreater than or equal to the first threshold value a1, the vector v is filtered out_k(ii) a BCI is indicated when interference code word is indicated as best interference code word_iWhen, e.g. the ratio f_kjLess than or equal to the second threshold value a2, the vector v is filtered out_k(ii) a Wherein a1 is more than 0 and less than 1, and a2 is more than 0 and less than 1.

Alternatively, the following method can be used to screen out vectors that do not meet the interference requirement:

each vector v in the vector space S_kObtaining a vector v 'after projecting the corresponding vector space to each interference code word'_kjCalculating post-projection vector v'_kjNorm of (d) and vector v before projection_kIs the ratio f of the norm of_kj(ii) a J is more than or equal to 1 and less than or equal to n, and n is the total number of the base stations which initiate the cooperation request to the cooperation execution base station;

each vector p corresponding to precoding matrix indicator PMI_sObtaining a vector p 'after the vector space projection corresponding to each interference code word is indicated'_siCalculating post-projection vector p'_siNorm of (d) and vector p before projection_sIs the ratio f of the norm of_si(ii) a I is more than or equal to 1 and less than or equal to n, and n is the total number of the base stations which initiate the cooperation request to the cooperation execution base station;

indicating WCI when interference code word indicates worst interference code word_iWhen, e.g. the ratio f_kjIs greater than or equal to the ratio f_siThe minimum value of (d), then screen out the vector v_k(ii) a BCI is indicated when interference code word is indicated as best interference code word_iWhen, e.g. the ratio f_kjIs less than or equal to the ratio f_siThe maximum value of (d), then the vector v is screened out_k；

Step S40 further includes the following features:

the coordination condition for the local station to perform coordinated multipoint transmission COMP comprises one or more of the following conditions:

a) the energy self-loss of the station meets the requirements, and comprises the following steps:

calculating the precoding vector w of the station_iVector p corresponding to PMI when transmitting in the indicated direction_iEnergy component L in the indicated direction_i，L_i＝SINR*f_i ²(ii) a Wherein,

' is a vector inner product symbol, ' | A | ' is a vector A is subjected to modulo operation, and SINR is the signal to interference plus noise ratio of a terminal under the station;

such as L_iIf the energy is larger than or equal to the energy threshold value, the precoding vector w is confirmed_iThe method is effective;

b) precoding vector w_iCompared with the precoding matrix PMI, the interference to the neighbor cell is lower, including:

precoding vector w_iObtaining a vector w 'after the vector space corresponding to each interference code word is indicated to be projected'_ijCalculating post-projection vector w'_ijNorm of (d); j is more than or equal to 1 and less than or equal to n, and n is the total number of the base stations which initiate the cooperation request to the cooperation execution base station;

vector p corresponding to precoding matrix indicator PMI_iObtaining a vector p 'after the vector space projection corresponding to each interference code word is indicated'_ijCalculating post-projection vector p'_ijNorm of (d); j is more than or equal to 1 and less than or equal to n, and n is the total number of the base stations which initiate the cooperation request to the cooperation execution base station;

indicating WCI when interference code word indicates worst interference code word_iJust like the vector w 'after projection'_ijNorm of (2) and post-projection vector p'_ijIs less than or equal to a third threshold a3, the precoding vector w is confirmed_iIn the WCI_iThe interference on the corresponding adjacent cell is smaller than that of the PMI; wherein a3 is more than 0 and less than 1;

BCI is indicated when interference code word is indicated as best interference code word_iJust like the vector w 'after projection'_ijNorm of (2) and post-projection vector p'_ijIs greater than or equal to a fourth threshold a4, the precoding vector w is confirmed_iThe interference of the PMI on the adjacent cell corresponding to the BCI is smaller than that of the PMI; 0 < a4 < 1;

for any precoding vector w_iIf the interference on all the adjacent regions is less than the interference of PMI, confirming the precoding vector w_iOtherwise, confirming the precoding vector w_iAnd (4) invalidation.

Wherein the vector w is precoded as described_iIf the condition that the station executes coordinated multi-point transmission COMP is not satisfied, the precoding vector w is_iAnd (4) invalidation.

Application example

As shown in FIG. 2, there are ue1 under the base station BBU1, ue2 under the base station BBU2, and ue3 under the base station BBU 3. The main signal channels of the BBUs 1 to ue1 are H1, the main signal channels of the BBUs 2 to ue2 are H2, and the main signal channels of the BBUs 3 to ue3 are H3; the interference channel of the BBUs 2 to ue1 is H21, the interference channel of the BBUs 3 to ue1 is H31, and the interference channel of the BBUs 3 to ue2 is H32. 3 cells (cell 1-3), each cell has one UE, 3 UEs (UE 1-3) respectively use cell 1-3 as their service cell. Interference situation: UE1 can see the interference of cells 2 and 3, UE2 can only see the interference of cell 3, and UE3 cannot see the interference of other cells.

Step S101, a terminal feeds back a signal to interference plus noise ratio (SINR) and a Precoding Matrix Indicator (PMI) to a base station of a service area where the terminal is located; if the terminal also detects interference, the terminal also feeds back interference code word indication information (BCI) to the base station of the service area where the terminal is located;

the UE1 feeds back BCI1, PMI1 and SINR1 to the indoor baseband processing unit BBU1 of the service area where the UE is located; the UE2 feeds back BCI2, PMI2 and SINR2 to a BBU2 of a service area where the UE is located; the UE3 feeds back the PMI3 and the SINR3 to the BBU3 of the service area where the UE is located.

Step S102, BBU1 sends a cooperation request to BBU3 and BCI 1; the BBU2 sends a cooperation request to BBU3 and sends BCI 2.

Wherein,

in step S103, since all the coordination initiating base stations received by the coordination performing base station BBU3 are BCIs, the vector space corresponding to each BCI is directly used as the interference null space of each coordination initiating base station.

Step S104, combining each interference null space by the BBU3 of the cooperative execution station, carrying out SVD on the combined null space, and obtaining a U matrix, a singular value matrix and a V matrix after decomposition;

and carrying out SVD on the combined matrix to obtain:

the singular values are as follows according to the sequence from big to small: 0.924, 0.7072, 0.3827;

v matrix: $V=[v_1,v_2,v_3]=$

$[\left(\begin{array}{c}0.3536+0.0000i\\ -0.2500-0.2500i\\ 0.5000+0.3535i\\ 0.6036+0.1036i\end{array}\right),\left(\begin{array}{c}-0.4619+0.4620i\\ 0.0001+0.6533i\\ 0.1914+0.1913i\\ 0.2706-0.0001i\end{array}\right),\left(\begin{array}{c}0.3536+0.5000i\\ -0.6036+0.1036i\\ -0.0000-0.3535i\\ -0.2501+0.2500i\end{array}\right)]$

step S105, the first 2 singular values σ₁、σ₂The sum of the sums with all 3 singular values σ₁、σ₂And σ₃Is 0.8099, greater than a threshold a (a-80%); from V in the V matrix₁、v₂Form a vector space S, S ═ v₁，v₂]；

Step S106, screening out vectors which do not meet the interference requirement, comprising the following steps:

the first vector v in the vector space S₁Obtaining a vector v 'after being projected to a vector space corresponding to BCI 1'₁₁Vector v 'after projection'₁₁Norm of (d) and vector v before projection₁Is the ratio f of the norm of₁₁0.8535; assuming that the threshold is 0.8, the ratio f₁₁Greater than a threshold; vector v₁Obtaining a vector v 'after being projected to a vector space corresponding to BCI 2'₁₂Vector v 'after projection'₁₂Norm of (d) and vector v before projection₁Is the ratio f of the norm of₁₂0.9301; assuming that the threshold is 0.8, the ratio f₁₁And the ratio f₁₂Are all greater than the threshold value of 0.8, so vector v is not screened out₁；

The second vector v in the vector space S₂Obtaining a vector v 'after being projected to a vector space corresponding to BCI 1'₂₁Vector v 'after projection'₂₁Norm of (d) and vector v before projection₂Is the ratio f of the norm of₂₁0.3827; assuming that the threshold is 0.8, the ratio f₂₁Less than a threshold; thus screening out vector v₂；

Thus, a precoding space $A=\{0.924*v_1\}=\left(\begin{array}{c}0.924*0.3536+0.924*0.0000i\\ 0.924*(-0.2500)-0.924*0.2500i\\ 0.924*0.5000+0.924*0.3535i\\ 0.924*0.6036+0.924*0.1036i\end{array}\right)$

Step S107, the vector corresponding to PMI3 is projected to the pre-coding space A to obtain a pre-coding vector w_i：

The vector space corresponding to PMI3 contains a vector p₁， $p_1=\left(\begin{array}{c}0.5000\\ -0.5000\\ -0.5000\\ 0.5000\end{array}\right)$

Vector p₁Projecting the pre-coding space A to obtain a pre-coding vector w₁；

Precoding vectors $w_1=\left(\begin{array}{c}0.3536+0.0000i\\ -0.2500-0.2500i\\ 0.5000+0.3535i\\ 0.6036+0.1035i\end{array}\right)$

Step S108, judging whether the energy self-loss of the station meets the requirement, comprising:

calculating the precoding vector w of the station_iVector p corresponding to PMI when transmitting in the indicated direction₁Energy component L in the indicated direction₁，L_i＝SINR*f₁ ²(ii) a Wherein,

calculate f₁＝0.3536，

When the SINR is 724.2, L is calculated₁90.5487, greater than the energy threshold (17), thus confirming that the self-loss of the station satisfies the requirement, the precoding vector w₁The method is effective;

step S109, determining the precoding vector w_iCompared with a precoding matrix PMI, whether the interference to the neighbor cell is lower:

precoding vector w₁Obtaining a vector w 'after being projected to a vector space corresponding to BCI 1'₁₁，w′₁₁Has a norm of 0.8535; vector P corresponding to precoding matrix indicator PMI3₁Obtaining a vector p 'after being projected to a vector space corresponding to BCI 1'₁₁，p′₁₁The norm of (a) is 0.2706; vector w 'after projection'₁₁Norm of (2) and post-projection vector p'₁₁Is 0.5829, greater than a threshold (0.2); then the precoding vector w is acknowledged₁The interference on the adjacent cell corresponding to the BCI1 is smaller than that of the PMI;

precoding vector w₁Obtaining a vector w 'after being projected to a vector space corresponding to BCI 2'₁₂，w′₁₂Has a norm of 0.9301; vector P corresponding to precoding matrix indicator PMI3₁Obtaining a vector p 'after being projected to a vector space corresponding to BCI 2'₁₂，p′₁₂Has a norm of 0.6361; vector w 'after projection'₁₁Norm of (2) and post-projection vector p'₁₁Is 0.294, greater than a threshold (0.2); then the precoding vector w is acknowledged₁The interference on the adjacent cell corresponding to the BCI2 is smaller than that of the PMI;

thus, for precoding vector w₁If the interference on all the adjacent regions is less than the interference of PMI, confirming the precoding vector w₁Is effective.

Validating a precoding vector w_iAll cooperation conditions, precoding vectors w, of coordinated multipoint transmission COMP are met_iIs effective.

As shown in fig. 3, an embodiment of the present invention provides a precoding generation apparatus for an inter-cell multi-antenna cooperative system, where the apparatus includes:

an interference null space processing module, which is used for the cooperative execution base station to calculate the interference null space of each cooperative initiation base station according to the interference code word indication information sent by each cooperative initiation base station(ii) a Combining interference null spaces of all cooperative initiating base stations, carrying out SVD on the combined null spaces, and obtaining a U matrix, a singular value matrix and a V matrix after decomposition; wherein, the singular value sigma in the singular value matrix corresponding to the V matrix_jSorting according to the numerical value from large to small;

the pre-coding space generation module is used for picking out vectors corresponding to the first r large singular values in the singular value matrix from the V matrix to form a vector space S; screening the vectors in the vector space S to screen out the vectors which do not meet the interference requirement, and screening the vectors v in the vector space S_kWith corresponding singular value σ_kMultiplying to obtain precoding space A, A ═ sigma [ sigma ]₁*v₁，σ₂*v₂，...，σ_r*v_t](ii) a The ratio of the accumulated sum of the first r large singular values of the singular value matrix to the sum of all singular values of the singular value matrix is greater than or equal to a threshold value a, and a is greater than 0 and less than 1; t is less than or equal to r, and t is the total number of vectors contained in the precoding space A;

a precoding vector generation module, configured to cooperate with the execution base station to indicate each vector p corresponding to the PMI of the precoding matrix of the base station_iProjecting the pre-coding space A to obtain a pre-coding vector w_i(ii) a I is more than or equal to 1 and less than or equal to l, and l is the total number of vectors corresponding to the PMI;

precoding vector checking module for precoding vectors w_iIf the cooperation condition of the station for performing coordinated multi-point transmission COMP is met, the precoding vector w is confirmed_iIs effective.

The interference code word indication information comprises worst interference code word indication WCI or best interference code word indication BCI; the worst interference codeword indication is used to indicate a maximum interference direction of the cooperative initiating base station, and the best interference codeword indication is used to indicate a minimum interference direction of the cooperative initiating base station.

If the cooperation execution base station receives the worst interference code word indication sent by the cooperation initiating base station, calculating an interference null space according to the interference maximum vector space corresponding to the worst interference code word indication, and taking the calculated interference null space as the interference null space of the cooperation initiating base station; and if the cooperation executing base station receives the best interference code word indication sent by the cooperation initiating base station, taking the vector space corresponding to the best interference code word indication as the interference null space of the cooperation initiating base station.

Wherein, screening out vectors that do not meet interference requirements comprises:

each vector v in the vector space S_kObtaining a vector v 'after projecting the corresponding vector space to each interference code word'_kjCalculating post-projection vector v'_kjNorm of (d) and vector v before projection_kIs the ratio f of the norm of_kj(ii) a J is more than or equal to 1 and less than or equal to n, and n is the total number of the base stations which initiate the cooperation request to the cooperation execution base station;

indicating WCI when interference code word indicates worst interference code word_iWhen, e.g. the ratio f_kjGreater than or equal to the first threshold value a1, the vector v is filtered out_k(ii) a BCI is indicated when interference code word is indicated as best interference code word_iWhen, e.g. the ratio f_kjLess than or equal to the second threshold value a2, the vector v is filtered out_k(ii) a Wherein a1 is more than 0 and less than 1, and a2 is more than 0 and less than 1.

Alternatively, the following method can be used to screen out vectors that do not meet the interference requirement:

each vector v in the vector space S_kObtaining a vector v 'after projecting the corresponding vector space to each interference code word'_kjCalculating post-projection vector v'_kjNorm of (d) and vector v before projection_kIs the ratio f of the norm of_kj(ii) a J is more than or equal to 1 and less than or equal to n, and n is the total number of the base stations which initiate the cooperation request to the cooperation execution base station;

each vector p corresponding to precoding matrix indicator PMI_sObtaining a vector p 'after the vector space projection corresponding to each interference code word is indicated'_siCalculating post-projection vector p'_siNorm of (d) and vector p before projection_sIs the ratio f of the norm of_si(ii) a I is more than or equal to 1 and less than or equal to n, and n is the total number of the base stations which initiate the cooperation request to the cooperation execution base station;

indicating WCI when interference code word indicates worst interference code word_iWhen, e.g. the ratio f_kjIs greater than or equal to the ratio f_siThe minimum value of (d), then screen out the vector v_k(ii) a BCI is indicated when interference code word is indicated as best interference code word_iWhen, e.g. the ratio f_kjIs less than or equal to the ratio f_siThe maximum value of (d), then the vector v is screened out_k。

The coordination condition for the local station to perform coordinated multipoint transmission COMP comprises one or more of the following conditions:

a) the energy self-loss of the station meets the requirements, and comprises the following steps:

calculating the precoding vector w of the station_iVector p corresponding to PMI when transmitting in the indicated direction_iEnergy component L in the indicated direction_i，L_i＝SINR*f_i ²(ii) a Wherein,

' is a vector inner product symbol, ' | A | ' is a vector A is subjected to modulo operation, and SINR is the signal to interference plus noise ratio of a terminal under the station;

such as L_iIf the energy threshold value is greater than or equal to a5, the precoding vector w is confirmed_iThe method is effective; wherein a5 is more than 0;

b) precoding vector w_iCompared with the precoding matrix PMI, the interference to the neighbor cell is lower, including:

precoding vector w_iObtaining a vector w 'after the vector space corresponding to each interference code word is indicated to be projected'_ijCalculating post-projection vector w'_ijNorm of (d); j is more than or equal to 1 and less than or equal to n, and n is the total number of the base stations which initiate the cooperation request to the cooperation execution base station;

vector p corresponding to precoding matrix indicator PMI_iObtaining a vector p 'after the vector space projection corresponding to each interference code word is indicated'_ijCalculating post-projection vector p'_ijNorm of (d); j is more than or equal to 1 and less than or equal to n, and n is the total number of the base stations which initiate the cooperation request to the cooperation execution base station;

indicating WCI when interference code word indicates worst interference code word_iJust like the vector w 'after projection'_ijNorm of (2) and post-projection vector p'_ijIs less than or equal to a third threshold a3, the precoding vector w is confirmed_iIn the WCI_iThe interference on the corresponding adjacent cell is smaller than that of the PMI; wherein a3 is more than 0 and less than 1;

BCI is indicated when interference code word is indicated as best interference code word_iJust like the vector w 'after projection'_ijNorm of (2) and post-projection vector p'_ijIs greater than or equal to a fourth threshold a4, the precoding vector w is confirmed_iThe interference of the PMI on the adjacent cell corresponding to the BCI is smaller than that of the PMI; 0 < a4 < 1;

for any precoding vector w_iIf the interference on all the adjacent regions is less than the interference of PMI, confirming the precoding vector w_iOtherwise, confirming the precoding vector w_iAnd (4) invalidation.

In the precoding generation method and apparatus for an inter-cell multi-antenna cooperative system provided in the above embodiments, the cooperative base stations calculate interference null spaces of each cooperative initiating base station and perform combined SVD decomposition, vectors corresponding to first r large singular values in a singular value matrix are selected from a V matrix obtained after decomposition to form a vector space S, the vectors in S are screened, a precoding vector is generated in a precoding space formed by the screened vectors and it is checked whether the precoding space meets COMP cooperation requirements, and the checked precoding vector is determined to be valid. The precoding vector generated by the invention can enable the cooperative base station to meet the requirement on the suppression of each path of interference, and improves the accuracy of precoding.

It will be understood by those skilled in the art that all or part of the steps of the above methods may be implemented by instructing the relevant hardware through a program, and the program may be stored in a computer readable storage medium, such as a read-only memory, a magnetic or optical disk, and the like. Alternatively, all or part of the steps of the foregoing embodiments may also be implemented by using one or more integrated circuits, and accordingly, each module/unit in the foregoing embodiments may be implemented in the form of hardware, and may also be implemented in the form of a software functional module. The present invention is not limited to any specific form of combination of hardware and software.

It should be noted that the present invention can be embodied in other specific forms, and various changes and modifications can be made by those skilled in the art without departing from the spirit and scope of the invention.

Claims (12)

1. A precoding generation method of an inter-cell multi-antenna cooperative system comprises the following steps:

the cooperative execution base station calculates interference null space of each cooperative initiation base station according to interference code word indication information sent by each cooperative initiation base station; combining interference null spaces of all cooperative initiating base stations, carrying out SVD on the combined null spaces, and obtaining a U matrix, a singular value matrix and a V matrix after decomposition; wherein, the singular value sigma in the singular value matrix corresponding to the V matrix_jSorting according to numerical values from large to small;

picking out vectors corresponding to the first r large singular values in the singular value matrix from the V matrix to form a vector space S; screening the vectors in the vector space S to screen out the vectors which do not meet the interference requirement, and screening the vectors v in the vector space S_kWith corresponding singular value σ_kMultiplying to obtain precoding space A, A ═ sigma [ sigma ]₁*v₁，σ₂*v₂，...，σ_r*v_t](ii) a The ratio of the accumulated sum of the first r large singular values of the singular value matrix to the sum of all singular values of the singular value matrix is greater than or equal to a threshold value a, and a is greater than 0 and less than 1; t is less than or equal to r, and t is the total number of vectors contained in the precoding space A;

the cooperative execution base station indicates each vector p corresponding to the PMI of the precoding matrix of the base station_iProjecting the pre-coding space A to obtain a pre-coding vector w_i(ii) a I is more than or equal to 1 and less than or equal to l, and l is the total number of vectors corresponding to the PMI;

e.g. precoding vector w_iIf the cooperation condition of the station for performing coordinated multi-point transmission COMP is met, the precoding vector w is confirmed_iIs effective.

2. The method of claim 1, wherein:

the interference code word indication information comprises worst interference code word indication WCI or best interference code word indication BCI; the worst interference codeword indication is used to indicate a maximum interference direction of the cooperative initiating base station, and the best interference codeword indication is used to indicate a minimum interference direction of the cooperative initiating base station.

3. The method of claim 2, wherein:

if the cooperation execution base station receives the worst interference code word indication sent by the cooperation initiating base station, calculating an interference null space according to the interference maximum vector space corresponding to the worst interference code word indication, and taking the calculated interference null space as the interference null space of the cooperation initiating base station;

and if the cooperation executing base station receives the best interference code word indication sent by the cooperation initiating base station, taking the vector space corresponding to the best interference code word indication as the interference null space of the cooperation initiating base station.

4. The method of claim 3, wherein:

screening out vectors that do not meet interference requirements, comprising:

each vector v in the vector space S_kObtaining a vector v 'after projecting the corresponding vector space to each interference code word'_kjCalculating post-projection vector v'_kjNorm of (d) and vector v before projection_kIs the ratio f of the norm of_kj(ii) a J is more than or equal to 1 and less than or equal to n, and n is the total number of the base stations which initiate the cooperation request to the cooperation execution base station;

indicating WCI when interference code word indicates worst interference code word_iWhen, e.g. the ratio f_kjGreater than or equal to the first threshold value a1, the vector v is filtered out_k(ii) a BCI is indicated when interference code word is indicated as best interference code word_iWhen, e.g. the ratio f_kjLess than or equal to the second threshold value a2, the vector v is filtered out_k(ii) a Wherein a1 is more than 0 and less than 1, and a2 is more than 0 and less than 1.

5. The method of claim 3, wherein:

screening out vectors that do not meet interference requirements, comprising:

each vector v in the vector space S_kObtaining a vector v 'after projecting the corresponding vector space to each interference code word'_kjCalculating post-projection vector v'_kjNorm of (d) and vector v before projection_kIs the ratio f of the norm of_kj(ii) a J is more than or equal to 1 and less than or equal to n, and n is the total number of the base stations which initiate the cooperation request to the cooperation execution base station;

each vector p corresponding to precoding matrix indicator PMI_sObtaining a vector p 'after the vector space projection corresponding to each interference code word is indicated'_siCalculating post-projection vector p'_siNorm of (d) and vector p before projection_sIs the ratio f of the norm of_si(ii) a I is more than or equal to 1 and less than or equal to n, and n is a cooperative execution baseThe total number of base stations for which the station initiates a cooperation request;

indicating WCI when interference code word indicates worst interference code word_iWhen, e.g. the ratio f_kjIs greater than or equal to the ratio f_siThe minimum value of (d), then screen out the vector v_k(ii) a BCI is indicated when interference code word is indicated as best interference code word_iWhen, e.g. the ratio f_kjIs less than or equal to the ratio f_siThe maximum value of (d), then the vector v is screened out_k。

6. The method of claim 3, 4 or 5, wherein:

the cooperation condition for the local station to perform COMP includes one or more of the following conditions:

a) the energy self-loss of the station meets the requirements, and comprises the following steps:

calculating the precoding vector w of the station_iVector p corresponding to PMI when transmitting in the indicated direction_iEnergy component L in the indicated direction_i，L_i＝SINR*f_i ²(ii) a Wherein,

' is a vector inner product symbol, ' | A | ' is a vector A is subjected to modulo operation, and SINR is the signal to interference plus noise ratio of a terminal under the station;

such as L_iIf the energy threshold value is greater than or equal to a5, the precoding vector w is confirmed_iThe method is effective; wherein a5 is more than 0;

b) precoding vector w_iCompared with the precoding matrix PMI, the interference to the neighbor cell is lower, including:

precoding vector w_iObtaining a vector w 'after the vector space corresponding to each interference code word is indicated to be projected'_ijCalculating post-projection vector w'_ijNorm of (d); j is more than or equal to 1 and less than or equal to n, and n is the total number of the base stations which initiate the cooperation request to the cooperation execution base station;

vector p corresponding to precoding matrix indicator PMI_iObtaining a vector p 'after the vector space projection corresponding to each interference code word is indicated'_ijCalculating post-projection vector p'_ijNorm of (d); j is more than or equal to 1 and less than or equal to n, and n is the total number of the base stations which initiate the cooperation request to the cooperation execution base station;

indicating WCI when interference code word indicates worst interference code word_iJust like the vector w 'after projection'_ijNorm of (2) and post-projection vector p'_ijIs less than or equal to a third threshold a3, the precoding vector w is confirmed_iIn the WCI_iThe interference on the corresponding adjacent cell is smaller than that of the PMI; wherein a3 is more than 0 and less than 1;

BCI is indicated when interference code word is indicated as best interference code word_iJust like the vector w 'after projection'_ijNorm of (2) and post-projection vector p'_ijIs greater than or equal to a fourth threshold a4, the precoding vector w is confirmed_iThe interference of the PMI on the adjacent cell corresponding to the BCI is smaller than that of the PMI; 0 < a4 < 1;

for any precoding vector w_iIf the interference on all the adjacent regions is less than the interference of PMI, confirming the precoding vector w_iOtherwise, confirming the precoding vector w_iAnd (4) invalidation.

7. A precoding generation apparatus of an inter-cell multi-antenna cooperative system, the apparatus comprising:

the interference null space processing module is used for the cooperative execution base station to calculate the interference null space of each cooperative initiation base station according to the interference code word indication information sent by each cooperative initiation base station; combining interference null spaces of all cooperative initiating base stations, carrying out SVD on the combined null spaces, and obtaining a U matrix, a singular value matrix and a V matrix after decomposition; wherein, the singular value sigma in the singular value matrix corresponding to the V matrix_jSorting according to numerical values from large to small;

the pre-coding space generation module is used for picking out vectors corresponding to the first r large singular values in the singular value matrix from the V matrix to form a vector space S; screening the vectors in the vector space S to screen out the vectors which do not meet the interference requirement, and screening the vectors v in the vector space S_kWith corresponding singular value σ_kMultiplication to obtain preCoding space a, a ═ σ₁*v₁，σ₂*v₂，...，σ_r*v_t](ii) a The ratio of the accumulated sum of the first r large singular values of the singular value matrix to the sum of all singular values of the singular value matrix is greater than or equal to a threshold value a, and a is greater than 0 and less than 1; t is less than or equal to r, and t is the total number of vectors contained in the precoding space A;

a precoding vector generation module, configured to cooperate with the execution base station to indicate each vector p corresponding to the PMI of the precoding matrix of the base station_iProjecting the pre-coding space A to obtain a pre-coding vector w_i(ii) a I is more than or equal to 1 and less than or equal to l, and l is the total number of vectors corresponding to the PMI;

precoding vector checking module for precoding vectors w_iIf the cooperation condition of the station for performing coordinated multi-point transmission COMP is met, the precoding vector w is confirmed_iIs effective.

8. The apparatus of claim 7, wherein:

the interference code word indication information comprises worst interference code word indication WCI or best interference code word indication BCI; the worst interference codeword indication is used to indicate a maximum interference direction of the cooperative initiating base station, and the best interference codeword indication is used to indicate a minimum interference direction of the cooperative initiating base station.

9. The apparatus of claim 8, wherein:

if the cooperation execution base station receives the worst interference code word indication sent by the cooperation initiating base station, calculating an interference null space according to the interference maximum vector space corresponding to the worst interference code word indication, and taking the calculated interference null space as the interference null space of the cooperation initiating base station;

and if the cooperation executing base station receives the best interference code word indication sent by the cooperation initiating base station, taking the vector space corresponding to the best interference code word indication as the interference null space of the cooperation initiating base station.

10. The apparatus of claim 9, wherein:

screening out vectors that do not meet interference requirements, comprising:

each vector v in the vector space S_kObtaining a vector v 'after projecting the corresponding vector space to each interference code word'_kjCalculating post-projection vector v'_kjNorm of (d) and vector v before projection_kIs the ratio f of the norm of_kj(ii) a J is more than or equal to 1 and less than or equal to n, and n is the total number of the base stations which initiate the cooperation request to the cooperation execution base station;

indicating WCI when interference code word indicates worst interference code word_iWhen, e.g. the ratio f_kjGreater than or equal to the first threshold value a1, the vector v is filtered out_k(ii) a BCI is indicated when interference code word is indicated as best interference code word_iWhen, e.g. the ratio f_kjLess than or equal to the second threshold value a2, the vector v is filtered out_k(ii) a Wherein a1 is more than 0 and less than 1, and a2 is more than 0 and less than 1.

11. The apparatus of claim 9, wherein:

screening out vectors that do not meet interference requirements, comprising:

each vector v in the vector space S_kObtaining a vector v 'after projecting the corresponding vector space to each interference code word'_kjCalculating post-projection vector v'_kjNorm of (d) and vector v before projection_kIs the ratio f of the norm of_kj(ii) a J is more than or equal to 1 and less than or equal to n, and n is the total number of the base stations which initiate the cooperation request to the cooperation execution base station;

each vector p corresponding to precoding matrix indicator PMI_sObtaining a vector p 'after the vector space projection corresponding to each interference code word is indicated'_siCalculating post-projection vector p'_siNorm of (d) and vector p before projection_sIs the ratio f of the norm of_si(ii) a I is more than or equal to 1 and less than or equal to n, and n is the total number of the base stations which initiate the cooperation request to the cooperation execution base station;

indicating WCI when interference code word indicates worst interference code word_iWhen, e.g. the ratio f_kjIs greater than or equal to the ratio f_siMinimum value of (1), thenScreen out the vector v_k(ii) a BCI is indicated when interference code word is indicated as best interference code word_iWhen, e.g. the ratio f_kjIs less than or equal to the ratio f_siThe maximum value of (d), then the vector v is screened out_k。

12. The apparatus of claim 9, 10 or 11, wherein:

the cooperation condition for the local station to perform COMP includes one or more of the following conditions:

a) the energy self-loss of the station meets the requirements, and comprises the following steps:

calculating the precoding vector w of the station_iVector p corresponding to PMI when transmitting in the indicated direction_iEnergy component L in the indicated direction_i，L_i＝SINR*f_i ²(ii) a Wherein,

' is a vector inner product symbol, ' | A | ' is a vector A is subjected to modulo operation, and SINR is the signal to interference plus noise ratio of a terminal under the station;

such as L_iIf the energy threshold value is greater than or equal to a5, the precoding vector w is confirmed_iThe method is effective; wherein a5 is more than 0;

b) precoding vector w_iCompared with the precoding matrix PMI, the interference to the neighbor cell is lower, including:

precoding vector w_iObtaining a vector w 'after the vector space corresponding to each interference code word is indicated to be projected'_ijCalculating post-projection vector w'_ijNorm of (d); j is more than or equal to 1 and less than or equal to n, and n is the total number of the base stations which initiate the cooperation request to the cooperation execution base station;

vector p corresponding to precoding matrix indicator PMI_iObtaining a vector p 'after the vector space projection corresponding to each interference code word is indicated'_ijCalculating post-projection vector p'_ijNorm of (d); j is more than or equal to 1 and less than or equal to n, and n is the total number of the base stations which initiate the cooperation request to the cooperation execution base station;

when the interference code word indication is the worst interference code word indicationWCI_iJust like the vector w 'after projection'_ijNorm of (2) and post-projection vector p'_ijIs less than or equal to a third threshold a3, the precoding vector w is confirmed_iIn the WCI_iThe interference on the corresponding adjacent cell is smaller than that of the PMI; wherein a3 is more than 0 and less than 1;

BCI is indicated when interference code word is indicated as best interference code word_iJust like the vector w 'after projection'_ijNorm of (2) and post-projection vector p'_ijIs greater than or equal to a fourth threshold a4, the precoding vector w is confirmed_iThe interference of the PMI on the adjacent cell corresponding to the BCI is smaller than that of the PMI; 0 < a4 < 1;

for any precoding vector w_iIf the interference on all the adjacent regions is less than the interference of PMI, confirming the precoding vector w_iOtherwise, confirming the precoding vector w_iAnd (4) invalidation.

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