WO2012094948A1

WO2012094948A1 - Coordinated precoding method, and coordinated information interaction method and system

Info

Publication number: WO2012094948A1
Application number: PCT/CN2011/085028
Authority: WO
Inventors: 陈艺戬; 李儒岳; 郁光辉; 郭森宝; 孙云锋
Original assignee: 中兴通讯股份有限公司
Priority date: 2011-01-12
Filing date: 2011-12-30
Publication date: 2012-07-19
Also published as: CN102075294A; CN102075294B

Abstract

Disclosed are a coordinated precoding method, a coordinated information interaction method and a system. The system includes a first eNodeB to which a first cell belongs and a first user terminal which the first cell serves, a second eNodeB to which a second cell belongs and a second user terminal which the second cell serves. On the same segment of time frequency resources, the symbols to be transmitted of the first user terminal are precoded by the first eNodeB using a first precoding weighted value in the first cell and then transmitted to the first terminal; the symbols to be transmitted of the second user terminal are precoded by the second eNodeB using a second precoding weighted value in the second cell and then transmitted to the second terminal; and the first precoding weighted value and the second precoding weighted value are in an orthogonal relationship. The method and system of the present invention use orthogonal coordinated precoding among cells to achieve the object of eliminating interference by utilizing the orthogonality of the receiving space.

Description

Collaborative precoding method, cooperative information interaction method and system

Technical field

The present invention relates to the field of mobile communication technologies, and in particular, to a cooperative precoding method, a cooperative information interaction method and system.

Background technique

In a wireless communication system, a cell (CELL) edge receives signals from a plurality of cells outside the serving cell to form strong interference. At this time, the SINR (Signal Interference Noise Ratio) of the radio signal received by the receiving terminal located at the edge of the cell is low, so the transmission performance of the user at the cell edge is relatively poor.

As shown in Figure 1, a schematic diagram of a scenario in which a cell edge user is interfered is given. In a wireless communication system, when each cell/base station transmits data using the same time-frequency domain resource location, the signal sent by the base station 2 (eNodeB 2) to the user terminal UE2 at the edge of the serving cell may be the base station 1 (eNodeB l) The user terminal UE1 at the edge of the serving cell forms interference, and the user terminal UE1 is subject to strong interference from the eNodeB2 signal. Similarly, the signal of the user terminal UE1 sent by the eNodeB1 to the edge of the serving cell may also form a strong interference to the cell edge user terminal UE2 served by the eNodeB2.

In the 4th generation wireless communication system (4G), such as the 3rd Generation Partnership Project (3GPP) Long Term Evolution (LTE) standard, due to the use of orthogonal frequency division multiplexing The (OFDM) technology is very sensitive to interference effects, so the performance problems of users at the edge of the cell appear to be more prominent. In the standard evolution process, the demand for spectrum efficiency at the cell edge is increasing, but there is currently no good way to solve the interference problem.

For example, one solution is to solve the interference problem by scheduling in the time domain or the frequency domain, which is commonly referred to as a cooperative scheduling technique. The simple cooperative scheduling technology can enable the users at the cell edge to avoid transmitting at the same time-frequency resource location at the same time as the users at the cell edge by the interaction of the information between the cells and the base stations. In FIG. 1 , the positions of the user terminals UE1 and UE2 are relatively similar, so that the interference scenario in the interference scenario shown in FIG. 1 is likely to generate strong interference, and the cooperative scheduling technique can be slowed to some extent. Solve the interference problem. However, in the scenario shown in FIG. 2, when UE1, UE2, and eNodeB2 are in the same straight line, when the three are in the same straight line or close to the same straight line, in the case that the channel has a direct channel (LOS) path, the eNodeB2 sends out The signal to UE2 may not be completely attenuated when it arrives at UE1, and there is a strong interference power arrival, so UE1 may still be subject to strong interference from eNB2. Therefore, the cooperative scheduling technology cannot solve the cell edge interference problem well by coordination in the time-frequency domain.

For example, another solution is to solve the interference problem by cooperative beamforming in the airspace. The schematic scenario of the application is shown in Figure 3. The cooperative beamforming of the airspace mainly performs beam coordination (also referred to as cooperative precoding) according to channel information. This technique can better eliminate interference. It relies on channel information feedback from UE1 to eNodeB2. It needs to feed back the channel information of subbands in each frequency domain, and increase the feedback amount of the uplink channel. Moreover, because it is at the edge of the cell, User feedback accuracy is also affected.

Summary of the invention

Therefore, existing problems in cooperative beamforming techniques based on airspace interference cancellation include:

(1) Compared with the single cell situation, the UE needs to feed back additional channel information, can not achieve mode transparency, and needs to design a new mode. For the standard version that has already been completed, the technology cannot be supported; (2) additional uplink is required. Channel feedback overhead; (3) When the UE1 measures the channel between the eNodeB2 and the channel between them, it will bring a certain channel estimation error, and the estimated channel information quantized by the feedback will also bring certain errors; (4) The eNodeB2 needs to ensure the transmission quality of the UE2 and does not interfere with the UE1. The two channels need to have good orthogonality. Therefore, it is necessary to select an appropriate UE2 during scheduling, which will bring certain scheduling restrictions. .

The technical problem to be solved by the present invention is to provide a cooperative precoding method, a cooperative information interaction method and system, which are used to solve the interference problem between adjacent cells.

In order to solve the above problem, the present invention provides a mobile communication system using cooperative precoding, including: a first base station to which a first cell belongs and a first user terminal served by a first cell, and a second user belonging to a second cell a second user terminal served by the base station and the second cell; wherein, in the same time-frequency resource, the first base station uses the first pre-encoding weight in the first cell to wait for the first user terminal Transmitting a symbol to perform precoding, and transmitting data to the first terminal; the second base station precoding the to-be-transmitted symbol of the second user terminal by using the second precoding weight in the second cell, and sending the data to the second terminal; The first precoding weight and the second precoding weight are orthogonal. Preferably, the first base station and the second base station are the same base station or different base stations, that is, the first cell and the second cell belong to the same base station or preferably, the first precoding weight W

Oh,

Wherein, respectively, a vector or matrix of ² xm, which is the number of transmitting antennas, m is a positive integer less than or equal to ² , "is any real number or complex number. Preferably, the ^ and ^ are the same or different vectors or matrix.

Preferably, the ^ and ^ are orthogonal relationships.

Preferably, the first precoding weight and the second precoding weight are respectively codewords in the 8 antenna layer 1 codebook in the LTE-A standard;

Or the codeword in the 4 antenna layer 1 codebook in the LTE/LTE-A standard;

Or extracting one or more columns of mutually orthogonal matrices from one codeword of the 8 antenna layer 4 codebook in the LTE-A standard;

Or respectively, two sets of mutually orthogonal in the set { }

V2

Preferably, the first cell feeds back precoding information on a part or all of the transmission resource locations to the second cell through the first base station to which the first cell belongs; and/or, the second cell passes the second base station to which the second cell belongs The first cell feeds back precoding information on the same or different transmission resources as the first cell.

Preferably, the precoding information is quantized using a precoding codebook, including using the codeword index information corresponding to the precoding codebook to represent the precoding information; or the precoding information is quantized using a parameter codebook, The method includes: the first cell and the second cell agree on a precoding model, and quantize the parameters in the model by using parameter index information corresponding to the parameter codebook. The present invention also provides a method for cooperative precoding in a mobile communication system, where the first base station to which the first cell belongs and the first user terminal served by the first cell, the second base station to which the second cell belongs, and the second In the mobile communication system of the second user terminal served by the cell, the method includes: on the same time-frequency resource, the first base station performs, on the first cell, the first pre-coding weight to perform the to-be-transmitted symbol of the first user terminal. Transmitting the data to the first terminal after precoding; the second base station precoding the to-be-transmitted symbol of the second user terminal by using the second precoding weight in the second cell, and transmitting the data to the second terminal; the first precoding The weight is orthogonal to the second precoding weight.

Preferably, the first base station and the second base station are the same base station or different base stations, that is, the first cell and the second cell belong to the same base station or, preferably, the first precoding weight W

Oh,

Preferably, the ^ and ^ are orthogonal relationships.

Or the codeword in the 4 antenna layer 1 codebook in the LTE/LTE-A standard;

Or respectively, two sets of mutually orthogonal in the set { }

V2

Preferably, the first cell feeds back precoding information on a part or all of the transmission resource locations to the second cell through the first base station to which the first cell belongs; and/or, the second cell passes the second base station to which the second cell belongs The first cell feeds back precoding information on the same or different transmission resources as the first cell. Preferably, the precoding information is quantized using a precoding codebook, including using the codeword index information corresponding to the precoding codebook to represent the precoding information; or the precoding information is quantized using a parameter codebook, The method includes: the first cell and the second cell agree on a precoding model, and quantize the parameters in the model by using parameter index information corresponding to the parameter codebook.

The present invention also provides an interaction method for d and interval cooperation information, which is applied to a first base station to which the first cell belongs and a first user terminal served by the first cell, and a second base station and a second cell to which the second cell belongs. In the mobile communication system of the second user terminal that is served, the interaction method includes: the first cell feeds back precoding information at a part or all of the transmission resource location to the second cell through the first base station to which the first cell belongs; Or,

The second cell feeds back precoding information on some or all of the transmission resource locations to the first cell through the second base station to which the second cell belongs.

Preferably, the method further includes: the second cell performs cooperative precoding according to the precoding information fed back by the first cell; and/or, the first cell performs cooperative precoding according to the precoding information fed back by the second cell. .

Preferably, the precoding information is quantized using a precoding codebook, including using the codeword index information corresponding to the precoding codebook to represent the precoding information; or the precoding information is quantized using a parameter codebook, The method includes: the first cell and the second cell agree on a precoding model, and quantize the parameters in the model by using parameter index information corresponding to the parameter codebook.

Preferably, the precoding information is quantized using the precoding codebook, further comprising: indicating the precoding codebook or the parameter codebook by using layer indication information.

Preferably, when the first cell and/or the second cell send precoding information, the N bits are used to represent precoding index information or parameter index information.

Preferably, when the first cell and/or the second cell send precoding information, the agreed model u

For a ] , a = l -\J -j , the first cell and/or the second cell use 2 bits to inform the coordinator of the parameter α information of the model F. Preferably, when the first cell and/or the second cell send precoding information, the defined model u

For F a,u , a = l -\J -j , the first cell and/or the second cell respectively use the au method of codebook quantization to quantize the parameter α, μ information of the model and then notify the collaborator. Preferably, when the first cell and/or the second cell send the precoding information, the LTE-A 4 antenna or the 8 antenna codebook or a subset thereof is used to quantize the precoding information, and the corresponding index information is notified to the collaborator.

The present invention also provides a mobile communication system using cooperative precoding, comprising: a first transmission node and a first user terminal served by the first transmission node, a second transmission node, and a second service provided by the second transmission node a user terminal; wherein, on the same time-frequency resource,

The first transmitting node pre-codes the to-be-transmitted symbol of the first user terminal by using the first pre-encoding weight to send data to the first terminal;

The second transmission node pre-codes the to-be-transmitted symbol of the second user terminal by using the second pre-encoding weight to send data to the second terminal;

The first precoding weight and the second precoding weight are in an orthogonal relationship.

The present invention also provides a method for cooperative precoding in a mobile communication system, comprising: a first transmission node and a first user terminal served by the first transmission node, a second transmission node, and a second transmission node In a mobile communication system of a two user terminal, the method includes:

On the same time-frequency resource, the first transmission node pre-codes the to-be-transmitted symbol of the first user terminal by using the first pre-encoding weight to send data to the first terminal; the second transmission node uses the second pre-encoding weight And pre-coding the to-be-transmitted symbol of the second user terminal, and sending the data to the second terminal; the first pre-encoding weight and the second pre-encoding weight are in an orthogonal relationship. The present invention also provides a method for interacting cooperative information, which is applied to a first user terminal that is served by a first transmission node and a first transmission node, and a second user terminal that is served by a second transmission node and a second transmission node. In the mobile communication system, the interaction method includes: the first transmission node feeding back to the second transmission node the precoding information at a part or all of the transmission resource locations; and/or,

The second transmission node feeds back to the first transmission node at a part or all of the transmission resource location Precoded information.

In the prior art, the interference signal is forced to zero based on the interference channel information, so that no interference signal arrives at the receiving end as much as possible, but the present invention uses orthogonal cooperative precoding between cells, and uses the orthogonality of the receiving space to achieve interference cancellation. The purpose is to allow the interference signal to arrive at the receiving end. Since the cooperative precoding makes the signals from different cells have orthogonality in the receiving space, the useful signal is extracted at the time of receiving, and the interference is reduced due to the orthogonal relationship. offset.

Compared with the prior art, the present invention has the following advantages:

(1) It is very suitable for the mainstream dual-polarized antenna configuration. At this time, although the SINR of the signal is large before the processing of the receiving algorithm, the interference can be well eliminated after the processing of the receiving algorithm, and the SINR is small and can be effectively eliminated. Interference; (2) The terminal does not need additional feedback; (3) Cooperative precoding does not require orthogonality of the channel itself, only orthogonality of cooperative precoding is required, and scheduling flexibility is high.

BRIEF abstract

1 is a schematic diagram of cell edge user interference;

2 is a schematic diagram of a scenario in which UE1, UE2, and eNodeB2 are in the same straight line; FIG. 3 is a schematic diagram of a scenario of cooperative beamforming in spatial domain interference cancellation;

Figure 4 is a schematic diagram of precoding and precoding information interaction.

Preferred embodiment of the invention

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be further described in detail with reference to the accompanying drawings.

In a specific embodiment of the present invention, a new cooperative precoding technical solution is proposed for the problem of inter-cell interference and cooperative precoding, which can be achieved without relying on additional feedback of the UE. Good purpose to eliminate interference. It can be applied to the scenarios in Figures 1 to 3. It can also be applied to scenarios with other neighboring cells. Further, an interactive technical scheme for inter-cell cooperation information is also given.

The cell A and the cell B are adjacent cells, and the cooperative precoding method of the two cells includes: The cell A pre-codes the to-be-transmitted symbol of the user UE1 to which it serves, and performs data transmission. At the same transmission resource location, the cell B pre-codes and transmits the data to be transmitted by the user UE2 serving the UE. And the sum is a precoding weight, and the two are orthogonal relationships. further. , _3⁄4 can be w _a -.

Where "., is a 2 x _m vector or matrix, the number of transmit antennas, m is a positive integer less than or equal to ² , "is any real or complex number. Further, ^M may be the same or different. Further ^M. Can be an orthogonal relationship. At the same time, an inter-cell cooperation information interaction method includes: the cell A feeds back to the cell B some or all of the precoding information on the transmission resource location; further, the cell B feeds back to the cell A some or all of the transmission resource locations. Encoding information.

The transmission and reception of the cell A and the cell B can be performed by the base station to which they belong, and the two can belong to the same base station or belong to different base stations.

In the mobile communication system in FIGS. 1 to 3, as shown in FIG. 4,

The first base station to which the cell A belongs sends the data to the terminal 1 after the cell A uses the first precoding weight to precode the to-be-transmitted symbol of the user terminal 1.

The second base station to which the cell B belongs sends the data to the terminal 2 after the cell B uses the second precoding weight ^ to precode the to-be-transmitted symbol of the user terminal 2.

The first precoding weight w _a and the second precoding weight ^ are in an orthogonal relationship.

The first base station and the second base station are the same base station or different base stations, that is, the first cell and the second cell belong to the same base station or belong to the first precoding weight W.

Where ^Ua , ^ are respectively a vector or matrix of xm, ^Λ ^ is the number of transmitting antennas, m A positive integer less than or equal to ² , "is any real number or complex number. The sum is the same or different vector or matrix. The sum is an orthogonal relationship. In the above communication system, as shown in Figure 4, the cell When the cooperation information between A and B is exchanged, the cell A feeds back some or all of the precoding information on the resource location to the cell B. Further, the cell B feeds back some or all of the precoding information on the resource location to the cell A. The transmission and reception of A and cell B can be done by the base station to which they belong, and both can belong to the same base station or different base stations.

Example 1:

It is assumed that there are a cell A and a cell B, and the two cells may belong to the same base station, or may not belong to the same base station, and perform coordinated transmission. Both cell A and cell B have Nt root transmit antennas. On a time-frequency transmission resource M, M is an RB (Resource Block) or a plurality of RBs, and Cell A pre-codes with its service user UE1 using ^W ", when Nt=8, that is, 8 transmit antennas ^w . It may be one codeword in the 8 antenna layer 1 codebook in the LTE-A standard.

LTE-A standard 8 antenna 1 layer

φ ft2 4 /32 6 /32 η

The parameter example can be

, where, for a complex number, can take the value 1, , -1 , j , lKm yi β

-j is equal, ^v is the DFT vector, ^v = [on the same time-frequency transmission resource, the cell 预 pre-codes its service user UE2 using ^, ^ can be the 8 antenna layer 1 codebook in the LTE-A standard One of the code words. For example, it can be

, where, for a complex number, = - ^Ψη is the DFT vector,

Through the above method, the signal transmitted to the UE1 in the cell may be cancelled or reduced after being processed by the UE2 receiving algorithm, and the signal transmitted by the B cell to the UE2 is also processed by the UE1 receiving algorithm. It is eliminated or reduced.

Example 2

There are cell A and cell B, which belong to or do not belong to the same base station, and perform cooperative transmission. Both cells A and B have Nt root transmit antennas.

On a time-frequency transmission resource M, M is an RB (Resource Block) or a plurality of RBs, and Cell A pre-codes the use of its serving user UE1. When Nt=4, it may be as shown in Table 1. One codeword in the 4-antenna layer 1 codebook in the LTE/LTE-A standard.

Where W _N =I lu _n lu _n , / is a unit matrix, and ^ω represents the column vector of the matrix ^. h ^Mn) represents a matrix composed of the jth, j _nth columns of the matrix _Wk . For example, it may be M7 _{fl = 0} W ₌ [l 1 1 i on the same time-frequency transmission resource M, and the cell B pre-codes the service user UE2 using w _b , which may be the 4 antenna layer 1 in the LTE-A standard. A codeword in the codebook. For example, it can be ^ = = [i 1 -1 - if or other orthogonal codewords in the 4 antenna codebook, for example, . It can also be pre-prepared with orthogonal precoding codewords using 4 antenna codebooks. coding. Example 3:

There are a cell A and a cell B, belonging to the same base station or belonging to different base stations, for cooperative transmission. Both cells A and B have Nt root transmit antennas.

On a time-frequency transmission resource M, M is an RB (Resource Block) or a plurality of RBs, and the cell A pre-codes the use of its serving user UE1, when Nt=8, ^w . It may be two of the columns of one of the 8 antenna layers in the LTE-A standard.

The 8 antennas of LTE-A are 4 layers:

丄

among them:

For example, it can be ^m a ^m a

w

φ v φ V is a complex number, which can take values 1, -1, j, -j, etc., v _m , is DFT

On the same time-frequency transmission resource, the cell 预 pre-codes its service user UE2 using w _b , which may be two of the code words of the 8 antenna layer 4 codebook in the LTE-A standard. For example, it can be

Where, for a complex number, φ _ηί = -φ _ηα , v _mh , is the DFT vector

It can be seen that _Wfl and w _b are orthogonal here. Through the above method, the signal transmitted to the UE1 in the A cell can be cancelled or reduced after being processed by the UE2 receiving algorithm, and the signal transmitted by the B cell to the UE2 is also processed after being processed by the UE1 receiving algorithm. It is eliminated or reduced. Example 4:

Similar to the third embodiment, the precoding weight may be:

V V

Ma ^m a

W

φ V -φ V φ V

^{1 n} am _b where ^ _{b is} orthogonal to ^ m _a . = or =- Alternatively, the precoding weight may be:

Where v and both are orthogonal, v, and are orthogonal, =^ or or, the precoding weights ^, ^ may be parameters of unequal dimensions, for example:

Where V is V and V are orthogonal, V, and V, V are orthogonal, Φ _η =Φ _η ^Φ _η = - _h

Embodiment 5: There are a cell A and a cell B, which belong to or do not belong to the same base station, and perform cooperative transmission. Both cells A and B have Nt root transmit antennas.

On a time-frequency transmission resource M, M is a resource block RB (Resource Block) or multiple resource blocks (RBs), and cell A pre-codes its service user UE1. It can be any of the following indexes (Index) 0~3.

In the same period of time-frequency resources on the transmission M, the cell B service to its users UE2 precoded using _w¾: When ^"=

Embodiment 6: There are a cell A and a cell B, which may belong to the same base station or belong to different base stations for cooperative transmission. The cell A sends the precoding information on the time-frequency transmission resource M to the cell B. M is a resource block RB (Resource Block) or a plurality of resource blocks (RBs); correspondingly, the cell B performs cooperative precoding according to precoding information and layer information transmitted by the cell A. Further, the cell A may send precoding information on the partial time-frequency transmission resource location M1 (M1 is a part of M) to the cell B; the cell B will additionally precoding information on a part of the time-frequency transmission resource location M2. Send to cell A. At the transmission resource location M1, the cell B performs cooperative precoding according to the precoding information transmitted by the cell A: At the transmission resource location M2, the cell A performs cooperative precoding according to the precoding information transmitted by the cell B. Further, the cell A and the cell B can transmit precoding information on the same time-frequency transmission resource location. For example, on the same time-frequency transmission resource M, the cell A sends the precoding information to the cell B, and the cell B also sends the precoding information to the cell A. Cell A and cell B re-negotiate for cooperative precoding. Embodiment 7: Precoding information is quantized using a precoding codebook, including using the codeword index information corresponding to the precoding codebook to represent the precoding information; or, the precoding information is quantized using a parameter codebook, including, A cell and a second cell agree on a precoding model, and quantize the parameters in the model using parameter index information corresponding to the parameter codebook. The quantizing the precoding information using the precoding codebook further comprises: indicating the precoding codebook or the parameter codebook using layer indication information. When the first cell and/or the second cell transmit precoding information, N bits are used to represent precoding index information or parameter index information.

When the first cell and/or the second cell send precoding information, the agreed model is u.

F(a), a = \-\ -j, the first cell and/or the second cell use 2 bits to inform the cooperative au party of the parameter information of the model F, the first cell and/or the second cell transmitting the pre- When encoding information, the defined model is u

F[a, u , a = l-\Jj, the first cell and/or the second cell respectively quantize the parameters α and μ of the model using the square au method of codebook quantization, and then notify the collaborator. When the first cell and/or the second cell send the precoding information, the LTE-A 4 antenna or the 8 antenna codebook or a subset thereof is used to quantize the precoding information, and the corresponding index information is notified to the collaborator. In a specific implementation, as described in Embodiment 6, when the cell or the cell B transmits the precoding information, the N bits are used to quantize the precoding information. For example, one or two bits are used to quantize layer information; N bits are used to represent precoding information. The precoding information is quantized using a subcodebook corresponding to the layer, and 2 ^W is equal to the number of codewords of the layer corresponding to the subcodebook. Of course, other codebooks can also be used. When the cell A or the cell B sends the precoding information, the codeword model can also be defined.

U

The model used by this party is given to the collaborator. If the model used for definition is _a = \ -\ -j , use au 2bit to inform the model F ( ) related α information to determine the specific F ( : Cell A or Cell B can also define the codeword model when transmitting precoding information ^c^), inform

U

Relevant alpha, μ information to determine the specific ;). The model used as defined limits the associated alpha, μ information to the usable amount of au bits. More generally, the above method can be used between different transport nodes:

A mobile communication system using cooperative precoding includes: a first transmission node and a first user terminal served by the first transmission node, a second transmission node, and a second user terminal served by the second transmission node; On the same time-frequency resource,

Correspondingly, the method for cooperative precoding in a mobile communication system includes: a first user node, a first user terminal served by the first transmission node, a second user node, and a second user terminal served by the second transmission node In a mobile communication system, the method includes:

On the same time-frequency resource, the first transmission node pre-codes the to-be-transmitted symbol of the first user terminal by using the first pre-encoding weight to send data to the first terminal; the second transmission node uses the second pre-encoding weight And pre-coding the to-be-transmitted symbol of the second user terminal, and sending the data to the second terminal; the first pre-encoding weight and the second pre-encoding weight are in an orthogonal relationship. Correspondingly, a method for interacting cooperative information is applied to a mobile communication including a first user node and a first user terminal served by the first transmission node, a second transmission node, and a second user terminal served by the second transmission node In the system, the interaction method includes: the first transmission node feeding back, to the second transmission node, precoding information at a part or all of the transmission resource locations; and/or,

The second transmission node feeds back precoding information at a portion or all of the transmission resource locations to the first transmission node.

It is worth noting that in the present invention and its specific embodiments, the vector or matrix described, each column multiplied by a constant coefficient belongs to the equivalent transformation of the present invention, and does not affect the implementation effect of the present invention. In addition, For all the matrices in the present invention, any column exchange of the columns it contains belongs to its equivalent transformation, and does not affect its implementation effect.

The above is only the embodiment of the present invention, and is not intended to limit the present invention, and various modifications and changes can be made to the present invention. All modifications, equivalents, improvements, etc., made within the spirit and scope of the invention are intended to be included within the scope of the appended claims.

Industrial Applicability The present invention has the following advantages over the prior art:

Claims

Claim

A mobile communication system using cooperative precoding, comprising: a first base station to which a first cell belongs and a first user terminal served by a first cell, and a second base station and a second cell to which the second cell belongs a second user terminal; wherein, on the same time-frequency resource,

The first base station sends data to the first terminal after the first cell uses the first precoding weight to precode the to-be-transmitted symbol of the first user terminal;

The second base station sends data to the second terminal after the second cell uses the second precoding weight to precode the to-be-transmitted symbol of the second user terminal;

2. The mobile communication system according to claim 1, wherein

The first base station and the second base station are the same base station or different base stations, that is, the first cell and the second cell belong to the same base station or belong to different base stations.

3. The first precoding weight W as claimed in claim 1 or 2

Oh,

Where, respectively, a vector or matrix of ² xm, ^{V f} is the number of transmitting antennas, and m is a positive integer less than or equal to ² , "is any real or complex number.

4. The mobile communication system according to claim 3, wherein said ^{U is} . And ^U b are the same or different vectors or matrices.

5. The mobile communication system according to claim 3, wherein said ^ and ^ are orthogonal relationships.

6. The mobile communication system according to claim 3, wherein

The first precoding weight and the second precoding weight are respectively codewords in the 8 antenna layer 1 codebook in the LTE-A standard; Or respectively, the codeword in the 4 antenna layer 1 codebook in the LTE/LTE-A standard; or the mutual obtained by extracting one or more columns from one codeword of the 8 antenna layer 4 codebook in the LTE-A standard, respectively. Orthogonal matrix;

Or respectively two sets of mutually orthogonal in the set { }

value.

The mobile communication system according to claim 3, wherein the first cell feeds back precoding information at a part or all of the transmission resource locations to the second cell through the first base station to which the first cell belongs;

And/or, the second cell feeds back, by the second base station to which the second cell belongs, the precoding information on the same or different transmission resources as the first cell to the first cell.

8. The mobile communication system according to claim 7, wherein

The precoding information is quantized by using a precoding codebook, including using the codeword index information corresponding to the precoding codebook to represent the precoding information; or the precoding information is quantized by using a parameter codebook, including: A cell and a second cell agree on a precoding model, and quantize the parameters in the model using parameter index information corresponding to the parameter codebook.

A method for cooperative precoding in a mobile communication system, comprising: a first base station to which the first cell belongs and a first user terminal served by the first cell, and a second base station and a second cell to which the second cell belongs In the mobile communication system of the second user terminal of the service, the method includes:

On the same time-frequency resource, the first base station uses the first pre-encoding weight to pre-code the to-be-transmitted symbol of the first user terminal, and then sends the data to the first terminal; the second base station uses the second cell in the second cell. The second pre-coding weight pre-codes the to-be-transmitted symbol of the second user terminal, and sends the data to the second terminal; the first pre-encoding weight and the second pre-encoding weight are in an orthogonal relationship.

10. The method of claim 9, wherein

11. The method according to claim 9 or 10, wherein The first precoding weight W

Oh,

Where is a ² xm vector or matrix, which is the number of transmitting antennas, m is a positive integer less than or equal to ² , "is any real or complex number.

12. The method of claim 11, wherein said ^U. And ^U b are the same or different vectors or matrices.

13. The method of claim 11, wherein the "" and ⁴ ^ are orthogonal relationships

14. The method of claim 11 wherein

The first precoding weight and the second precoding weight are respectively codewords in the 8 antenna layer 1 codebook in the LTE-A standard; or respectively, in the 4 antenna layer 1 codebook in the LTE/LTE-A standard Codeword

Or respectively, two sets of mutually orthogonal in the set { }

V2

Value _£

The method according to claim 11, wherein the first cell feeds back precoding information at a part or all of the transmission resource locations to the first cell through the first base station to which the first cell belongs; and/or,

The second cell feeds back, by the second base station to which the second cell belongs, the precoding information on the same or different transmission resources as the first cell.

16. The method of claim 15, wherein

The precoding information is quantized using a precoding codebook, including using a precoding codebook The codeword index information indicates the precoding information; or the precoding information is quantized using the parameter codebook, including: the first cell and the second cell contract precoding model, and using a parameter index corresponding to the parameter codebook The parameters in the information quantification model.

An interaction method for inter-cell cooperation information, which is applied to a first base station to which a first cell belongs and a first user terminal served by a first cell, and a second base station and a second cell to which the second cell belongs In the mobile communication system of the second user terminal, the interaction method includes: the first cell feeding back, by the first base station to which the first cell belongs, precoding information on a part or all of the transmission resource locations to the second cell; and/or,

The interaction method according to claim 17, wherein the method further comprises: performing, by the second cell, cooperative precoding according to precoding information fed back by the first cell; and/or, the first cell according to the first The precoding information fed back by the two cells is cooperatively precoded.

The interaction method according to claim 17 or 18, wherein the precoding information is quantized using a precoding codebook, including using the codeword index information corresponding to the precoding codebook to represent the precoding information;

Or,

The precoding information is quantized using a parameter codebook, including: the first cell and the second cell are determined by a precoding model, and the parameter in the model is quantized using parameter index information corresponding to the parameter codebook.

The interaction method of claim 19, wherein the precoding information is quantized using the precoding codebook further comprises: using the layer indication information to indicate the precoding codebook or the parameter codebook.

21. The interaction method according to claim 19, wherein

When the first cell and/or the second cell transmit precoding information, N bits are used to represent precoding index information or parameter index information.

22. The interaction method according to claim 19, wherein When the first cell and/or the second cell send precoding information, the agreed model is u

F (a) , a = l -\J -j , the first cell and/or the second cell use 2 bits to inform the cooperative au side of the parameter α information of the model F («).

The interaction method according to claim 19, wherein when the first cell and/or the second cell send precoding information, the defined model is u.

F , u , a = \ -\ -j , the first cell and/or the second cell respectively use the code-quantization method to quantize the parameter α and μ information of the model and then notify the collaborator.

The interaction method according to claim 19, wherein, when the first cell and/or the second cell send precoding information, the LTE-A 4 antenna or the 8 antenna codebook or a subset thereof is used to quantize the precoding information. And inform the collaborators of the corresponding index information.

25. A mobile communication system using cooperative precoding, comprising: a first transmission node and a first user terminal served by the first transmission node, a second transmission node, and a second user terminal served by the second transmission node; Among them, on the same time-frequency resource,

26 . A method for cooperative precoding in a mobile communication system, comprising: a first user node, a first user terminal served by the first transmission node, a second user node, and a second user terminal served by the second transmission node In a mobile communication system, the method includes:

On the same time-frequency resource, the first transmission node pre-codes the to-be-transmitted symbol of the first user terminal by using the first pre-encoding weight to send data to the first terminal; the second transmission node uses the second pre-encoding weight Precoding the symbol to be transmitted of the second user terminal and transmitting the data to the second terminal And the first precoding weight and the second precoding weight are orthogonal relationships.

27. An interaction method for cooperative information, comprising: a first user terminal, a first user terminal served by a first transmission node, a second transmission node, and a second user terminal serving a second user terminal The interaction method includes: the first transmission node feeding back, to the second transmission node, precoding information at a part or all of the transmission resource locations; and/or,