CN102447534A - Data transmission method and system of multiple-input multiple-output (MIMO) system - Google Patents

Abstract

The invention discloses a data transmission method and system of a multiple-input multiple-output (MIMO) system. The method comprises the following steps: obtaining the user information of an interference source by each base station according to interactive user dispatching information, also obtaining interference information by measuring the channel information of a user to be interfered and transmitting the interference information to a base station to which the user with the interference source belongs; forming equivalent interference information by the base station to which the user with the interference source belongs according to the received interference information, also obtaining information relating to precoding on a time-frequency resource block by utilizing the equivalent interference information and the self channel information of the user to be served and also transmitting the information to the user to be interfered; and receiving the information relating to precoding by the user to be interfered, obtaining optimal precoding information and also regulating a transmission signal by using the optimal precoding information. By an information interacting mechanism and a data precoding mechanism according to the data transmission method and system of the MIMO system, only simple information interaction is needed between the base stations, and most of interference can be suppressed, so that the transmission quality of uplink data is enhanced.

Description

Data transmission method and system for MIMO system

Technical Field

The invention relates to the field of communication, in particular to a data transmission technology of a multi-input multi-output MIMO system.

Background

The Multiple-Input Multiple-Output (MIMO) technology is a major breakthrough of the intelligent antenna technology in the field of wireless mobile communication, and the technology not only can improve the capacity and the spectrum utilization rate of a communication system by multiples without increasing the bandwidth, but also can utilize multipath to reduce multipath fading, effectively eliminate channel interference, improve the reliability of a channel and reduce the error rate.

For a wireless communication system with a cellular structure arranged network, the co-channel interference of neighboring cells is one of the most important factors causing the degradation of communication quality, and especially in uplink, the interference source is a data signal sent by a user of a neighboring cell on the same co-channel resource at the same time, so that the interference level changes rapidly, which brings huge challenges and difficulties to common interference suppression and power control algorithms, so in B3G and 4G wireless communication systems, a multi-cell cooperative MIMO technique is introduced to combat the co-channel interference, and the main idea is to use the MIMO technique to zero the interference of neighboring cells, and the premise of the nulling is that each user must know the interference channel from itself to the neighboring cell, thereby properly precoding data, and minimizing the interference to the neighboring cells while maximizing the transmission of its own data. Therefore, the cooperative base station MIMO is that a plurality of adjacent base stations measure channels of subordinate users and channels of interfering users, and then the channel information of the interfering users is notified to the cooperative base station in a certain manner, so that the cooperative base station performs interference avoidance processing.

Disclosure of Invention

The invention aims to provide a data transmission method and a data transmission system of a multi-input multi-output MIMO system, which can better solve the problem of the transmission quality of uplink data.

According to an aspect of the present invention, a data transmission method for a MIMO system is provided, including:

A) each base station in the base station set participating in the cooperation interacts user scheduling information on the time-frequency resource blocks through a network backbone or a backbone network or a special interface between the base stations;

B) each base station in the base station set participating in the cooperation acquires interference source user information according to user scheduling information on a time-frequency resource block, acquires the interference information by measuring channel information between an interference source user and the base station, and sends the interference information to the base station to which the interference source user belongs;

C) each base station receives interference information sent by other base stations in the cooperative base station set, and equivalent interference information is formed according to the interference information;

D) each base station obtains information about precoding on a time-frequency resource block by using equivalent interference information and channel information from a served user to the base station, and sends the information to the served user;

E) and the user obtains optimal precoding information according to the received information about precoding, and adjusts the sending signal by utilizing the optimal precoding information.

According to another aspect of the present invention, there is provided a data transmission system of a MIMO system, comprising:

the information interaction unit is used for interacting the user scheduling information of the base stations in the base station set participating in the cooperation in the time-frequency resource block through a network backbone or a backbone network or a direct special interface of the base stations;

the interference information calculation and transmission unit is used for obtaining interference source user information according to user scheduling information on a time-frequency resource block, obtaining interference information through measured channel information of the interference source user, and transmitting the interference information to a base station to which the interference source user belongs;

the equivalent interference information generating unit is used for receiving interference information sent by other base stations in the cooperative base station set and forming equivalent interference information according to the interference information;

the optimal precoding information generating and sending unit is used for generating information about precoding on a time-frequency resource block by utilizing equivalent interference information and channel information from a user to the user under the base station, and sending the information to the adjusting unit;

and the adjusting unit is used for receiving the information about the precoding to obtain the optimal precoding information and adjusting the sending signal by utilizing the optimal precoding information.

Compared with the prior art, the invention has the beneficial effects that: according to the invention, through the information interaction mechanism and the pre-coding mechanism of the cooperative base station, the cooperative base station can inhibit most interference only by carrying out simple information interaction, so that the transmission quality of uplink data is improved.

Drawings

Fig. 1 is a flow chart of a data transmission method of a MIMO system according to the present invention;

fig. 2 is a diagram of a data transmission system structure of a MIMO system according to the present invention;

fig. 3 is a network diagram of a data transmission system of a MIMO system according to an embodiment of the present invention.

Detailed Description

The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings, and it should be understood that the preferred embodiments described below are only for the purpose of illustrating and explaining the present invention, and are not to be construed as limiting the present invention.

Fig. 1 shows a flow chart of a data transmission method of a MIMO system according to the present invention, as shown in fig. 1, the steps are as follows:

step 101: base station set omega ═ { BS) participating in cooperation₁，BS₂，L，BS_NEach base station in the system interacts user scheduling information on time frequency resource blocks through a network backbone or a backbone network or a special interface between the base stations, so that each base station obtains a user set scheduled by all adjacent base stations on each time frequency resource block;

step 102: each base station in the base station set participating in the cooperation acquires interference source user information according to user scheduling information on a time-frequency resource block, acquires interference information by measuring channel information from the interference source user to the base station to which the interference source user belongs, and sends the interference information to the base station to which the interference source user belongs;

step 103: each base station receives interference information sent by other base stations in the cooperative base station set, and equivalent interference information is formed according to the interference information;

step 104: each base station obtains information about precoding on a time-frequency resource block by using equivalent interference information and channel information from a served user to the base station, and sends the information to the served user;

step 105: and the served users receive information about precoding to obtain optimal precoding information, adjust the sending signals by utilizing the optimal precoding information, and then map the sending signals to corresponding antennas to send out.

The step 102 may specifically be:

each base station in the base station set participating in the cooperation acquires information of an interference source user according to user scheduling information of other base stations on a time-frequency resource block;

each base station in the cooperative base station set carries out singular value decomposition or pair (H) on the channel information H from the interference source user to the base station^HH or E ((H)^HH) Performing characteristic decomposition to obtain a right singular matrix or a characteristic vector matrix V;

extracting the first n columns of vectors of V to generate interference information VⁿSending the interference information to a base station k to which the interference source user belongs;

in this case, the equivalent interference information in step 103 is <math> <mrow> <msub> <mi>H</mi> <mi>I</mi> </msub> <mo>=</mo> <mfenced open='[' close=']'> <mtable> <mtr> <mtd> <msubsup> <mi>V</mi> <mrow> <mi>j</mi> <mn>1</mn> </mrow> <mi>n</mi> </msubsup> </mtd> <mtd> <mo>&CenterDot;</mo> <mo>&CenterDot;</mo> <mo>&CenterDot;</mo> </mtd> <mtd> <mo>&CenterDot;</mo> <mo>&CenterDot;</mo> <mo>&CenterDot;</mo> </mtd> <mtd> <msubsup> <mi>V</mi> <mi>jm</mi> <mi>n</mi> </msubsup> </mtd> </mtr> </mtable> </mfenced> <mo>;</mo> </mrow> </math>

Wherein n is determined by the base station according to the decomposition of the channel information H; m is a user set scheduled by a base station j on the same time-frequency resource block, j is not equal to k, j is 1, …, and N.

The step 102 may specifically be:

each base station in the base station set participating in the cooperation acquires information of an interference source user according to user scheduling information of other base stations on a time-frequency resource block;

each base station in the cooperative base station set quantizes the channel information H from the interference source user to the base station into a code word in the codebook set

And according to the code word

A corresponding index is obtained, and the index is obtained, $\mathrm{PMI}=\arg \underset{\mathrm{PMI}}{\max }\left|\right|{\left(H\right)}^H{W}_{\mathrm{PMI}}^n\left|\right|$ or $\mathrm{PMI}=\arg \underset{\mathrm{PMI}}{\max }\left|\right|{\left(W_{\mathrm{PMI}}^n\right)}^{H}H\left|\right|;$

Transmitting the index PMI to a base station k to which an interference source user belongs through a backbone network connected with the base stations or a network backbone or a special interface between the base stations;

in this case, the equivalent interference information in step 103 is <math> <mrow> <msub> <mi>H</mi> <mi>I</mi> </msub> <mo>=</mo> <mfenced open='[' close=']'> <mtable> <mtr> <mtd> <msubsup> <mi>W</mi> <msub> <mi>PMI</mi> <mrow> <mi>j</mi> <mn>1</mn> </mrow> </msub> <mi>n</mi> </msubsup> </mtd> <mtd> <mo>&CenterDot;</mo> <mo>&CenterDot;</mo> <mo>&CenterDot;</mo> </mtd> <mtd> <mo>&CenterDot;</mo> <mo>&CenterDot;</mo> <mo>&CenterDot;</mo> </mtd> <mtd> <msubsup> <mi>W</mi> <msub> <mi>PMI</mi> <mi>jm</mi> </msub> <mi>n</mi> </msubsup> </mtd> </mtr> </mtable> </mfenced> <mo>;</mo> </mrow> </math>

Where N is determined by the base station according to the decomposition of the channel information H, m is a user set scheduled by the base station j on the same time-frequency resource block, j ≠ k, j ═ 1, …, N.

The step 102 may specifically be:

each base station in the base station set participating in the cooperation acquires information of an interference source user according to user scheduling information of other base stations on a time-frequency resource block;

each base station in the base station set participating in the cooperation transmits channel information H from the interference source user to the base station k to which the interference source user belongs through a backbone network connected with the base stations or a network backbone or a special interface between the base stations;

in this case, the equivalent information in step 103 is <math> <mrow> <msub> <mi>H</mi> <mi>I</mi> </msub> <mo>=</mo> <mfenced open='[' close=']'> <mtable> <mtr> <mtd> <msub> <mi>H</mi> <mrow> <mi>j</mi> <mn>1</mn> </mrow> </msub> </mtd> <mtd> <mo>&CenterDot;</mo> <mo>&CenterDot;</mo> <mo>&CenterDot;</mo> </mtd> <mtd> <mo>&CenterDot;</mo> <mo>&CenterDot;</mo> <mo>&CenterDot;</mo> </mtd> <mtd> <msub> <mi>H</mi> <mi>jm</mi> </msub> </mtd> </mtr> </mtable> </mfenced> <mo>;</mo> </mrow> </math>

Where m is a user set scheduled by a base station j on the same time-frequency resource block, j ≠ k, j ═ 1, …, N.

The step 104 may specifically be, in combination with the above three cases:

the base station k obtains the maximum gain transmission information W by using the channel information from the served user to the base station k_MRT；

k utilizing said H_IAnd said W_MRTObtaining interference minimized transmission information <math> <mrow> <msub> <mi>W</mi> <mi>ZF</mi> </msub> <mo>=</mo> <msubsup> <mi>&Pi;</mi> <msub> <mi>H</mi> <mi>I</mi> </msub> <mo>&perp;</mo> </msubsup> <msub> <mi>W</mi> <mi>MRT</mi> </msub> <mo>;</mo> </mrow> </math>

Base station k obtains optimal precoding for serving usersInformation W ═ orth (λ W)_MRT+(1-λ)W_ZF) And sending the data to the interfered user through a downlink control channel;

wherein,

orth (-) denotes the orthonormal operation on the input parameters, λ ∈ [0, 1]]。

The step 104 may further specifically be:

the base station k obtains the maximum gain transmission information W by using the channel information from the served user to the base station k_MRTAnd quantized into codewords in a codebook set

Then, a code word is obtained

Corresponding index ${\mathrm{PMI}}_{\mathrm{MRT}}=\arg \underset{\mathrm{PMI}}{\max }\left|\right|{\left(W_{\mathrm{MRT}}\right)}^H{W}_{{\mathrm{PMI}}_{\mathrm{MRT}}}\left|\right|$ Or ${\mathrm{PMI}}_{\mathrm{MRT}}=\arg \underset{\mathrm{PMI}}{\max }\left|\right|{\left(W_{{\mathrm{PMI}}_{\mathrm{MRT}}}\right)}^H{W}_{\mathrm{MRT}}\left|\right|;$

Base station k utilizes the H_IAnd said W_MRTObtaining interference minimized transmission informationAnd quantized into codewords in a codebook set

Then, a code word is obtainedCorresponding index

Or

Base station sends PMI through downlink control channel_MRTAnd PMI_ZFTransmitting to the user under the base station;

wherein, <math> <mrow> <msubsup> <mi>&Pi;</mi> <msub> <mi>H</mi> <mi>I</mi> </msub> <mo>&perp;</mo> </msubsup> <mo>=</mo> <msub> <mrow> <mi>I</mi> <mo>-</mo> <mi>H</mi> </mrow> <mi>I</mi> </msub> <msup> <mrow> <mo>(</mo> <msubsup> <mi>H</mi> <mi>I</mi> <mi>H</mi> </msubsup> <msub> <mi>H</mi> <mi>I</mi> </msub> <mo>)</mo> </mrow> <mrow> <mo>-</mo> <mn>1</mn> </mrow> </msup> <msubsup> <mi>H</mi> <mi>I</mi> <mi>H</mi> </msubsup> <mo>.</mo> </mrow> </math>

in this case, the step 105 specifically includes: user based on received PMI_MRTAnd PMI_ZFGet the index as PMI_MRTCode word of

And indexed as PMI_ZFCode word of

And obtaining the optimal precoding information for adjusting the transmission signal by the following formula:

<math> <mrow> <mi>W</mi> <mo>=</mo> <mi>orth</mi> <mrow> <mo>(</mo> <mi>&lambda;</mi> <msub> <mi>W</mi> <msub> <mi>PMI</mi> <mi>MRT</mi> </msub> </msub> <mo>+</mo> <mrow> <mo>(</mo> <mn>1</mn> <mo>-</mo> <mi>&lambda;</mi> <mo>)</mo> </mrow> <msub> <mi>W</mi> <msub> <mi>PMI</mi> <mi>ZF</mi> </msub> </msub> <mo>)</mo> </mrow> </mrow> </math>

wherein orth (·) represents the orthonormal operation performed on the input parameters, and λ ∈ [0, 1 ].

The step 104 may further specifically be:

the base station K obtains the maximum gain transmission information W by utilizing the channel information from the served user to the base station K_MRT；

Base station K utilizes the H_IAnd said W_MRTObtaining interference minimized transmission information <math> <mrow> <msub> <mi>W</mi> <mi>ZF</mi> </msub> <mo>=</mo> <msubsup> <mi>&Pi;</mi> <msub> <mi>H</mi> <mi>I</mi> </msub> <mo>&perp;</mo> </msubsup> <msub> <mi>W</mi> <mi>MRT</mi> </msub> <mo>;</mo> </mrow> </math>

Base station K obtains precoding information W ═ orth (λ W)_MRT+(1-λ)W_ZF) And quantized into codewords in a codebook set

Then, a code word is obtained

Corresponding index

Or ${\mathrm{PMI}}_W=\arg \underset{\mathrm{PMI}}{\max }\left|\right|{\left(W_{{\mathrm{PMI}}_W}\right)}^{H}W\left|\right|;$

Base station K indexes PMI through downlink control channel_WTo the served user;

wherein,

orth (-) denotes the orthonormal operation on the input parameters, λ ∈ [0, 1]]。

In this case, the step 105 specifically includes: the user served by the base station K receives the PMI_WTo obtain the optimal precoding information

And regulate transmissionA signal; the above-mentioned

For indexing PMI_WThe code word of (1).

The step 102 may further specifically be:

each base station in the base station set participating in the cooperation acquires information of an interference source user according to user scheduling information of other base stations on a time-frequency resource block;

each base station in the base station set participating in cooperation quantizes channel information H from interference source user to itself into code words in the codebook set WAnd according to the code wordGet the corresponding index $\mathrm{PMI}=\arg \underset{\mathrm{PMI}}{\min }\left|\right|{\left(H\right)}^H{W}_{\mathrm{PMI}}^n\left|\right|$ Or $\mathrm{PMI}=\arg \underset{\mathrm{PMI}}{\min }\left|\right|{\left(W_{\mathrm{PMI}}^n\right)}^{H}H\left|\right|;$

Transmitting the index PMI to a base station k to which an interference source user belongs through a backbone network connected with the base stations or a network backbone or a special interface between the base stations;

in this case, the equivalent information in step 103 is <math> <mrow> <msub> <mi>H</mi> <mi>I</mi> </msub> <mo>=</mo> <mfenced open='[' close=']'> <mtable> <mtr> <mtd> <msubsup> <mi>W</mi> <msub> <mi>PMI</mi> <mrow> <mi>j</mi> <mn>1</mn> </mrow> </msub> <mi>n</mi> </msubsup> </mtd> <mtd> <mo>&CenterDot;</mo> <mo>&CenterDot;</mo> <mo>&CenterDot;</mo> </mtd> <mtd> <mo>&CenterDot;</mo> <mo>&CenterDot;</mo> <mo>&CenterDot;</mo> </mtd> <mtd> <msubsup> <mi>W</mi> <msub> <mi>PMI</mi> <mi>jm</mi> </msub> <mi>n</mi> </msubsup> </mtd> </mtr> </mtable> </mfenced> <mo>;</mo> </mrow> </math>

Where N is determined by the base station according to the decomposition of the channel information H, m is a user set scheduled by the base station j on the same time-frequency resource block, j ≠ k, j ═ 1, …, N.

In this case, the step 104 may specifically be:

the base station k obtains the maximum gain transmission information W by using the channel information from the served user to the base station k_MRT；

Base station k utilizes the H_IAnd said W_MRTObtaining interference minimized transmission information <math> <mrow> <msub> <mi>W</mi> <mi>ZF</mi> </msub> <mo>=</mo> <msubsup> <mi>&Pi;</mi> <msub> <mi>H</mi> <mi>I</mi> </msub> <mo>&perp;</mo> </msubsup> <msub> <mi>W</mi> <mi>MRT</mi> </msub> <mo>;</mo> </mrow> </math>

Base station k obtains optimal precoding information W ═ orth (λ W) for served users_MRT+(1-λ)W_ZF) And sending the data to the served user through a downlink control channel;

wherein,

orth (-) denotes the orthonormal operation on the input parameters, λ ∈ [0, 1]]。

The step 104 may further specifically be:

the base station k obtains the maximum gain transmission information W by using the channel information from the user to the base station k_MRTAnd quantized into codewords in a codebook set

Then, a code word is obtained

Corresponding index ${\mathrm{PMI}}_{\mathrm{MRT}}=\arg \underset{\mathrm{PMI}}{\max }\left|\right|{\left(W_{\mathrm{MRT}}\right)}^H{W}_{{\mathrm{PMI}}_{\mathrm{MRT}}}\left|\right|$ Or ${\mathrm{PMI}}_{\mathrm{MRT}}=\arg \underset{\mathrm{PMI}}{\max }\left|\right|{\left(W_{{\mathrm{PMI}}_{\mathrm{MRT}}}\right)}^H{W}_{\mathrm{MRT}}\left|\right|;$

Base station k utilizes the H_IAnd said W_MRTObtaining interference minimized transmission information

And quantized into codewords in a codebook set

Then, a code word is obtained

Corresponding indexOr

PMI of base station k to which user belongs through downlink control channel_MRTAnd PMI_ZFTransmitting to the user;

wherein, <math> <mrow> <msubsup> <mi>&Pi;</mi> <msub> <mi>H</mi> <mi>I</mi> </msub> <mo>&perp;</mo> </msubsup> <mo>=</mo> <msub> <mi>H</mi> <mi>I</mi> </msub> <msup> <mrow> <mo>(</mo> <msubsup> <mi>H</mi> <mi>I</mi> <mi>H</mi> </msubsup> <msub> <mi>H</mi> <mi>I</mi> </msub> <mo>)</mo> </mrow> <mrow> <mo>-</mo> <mn>1</mn> </mrow> </msup> <msubsup> <mi>H</mi> <mi>I</mi> <mi>H</mi> </msubsup> <mo>.</mo> </mrow> </math>

in this case, the step 105 specifically includes:

user based on received PMI_MRTAnd PMI_ZFGet the index as PMI_MRTCode word ofAnd indexed as PMI_ZFCode word of

And obtaining the optimal precoding information for adjusting the transmission signal by the following formula:

<math> <mrow> <mi>W</mi> <mo>=</mo> <mi>orth</mi> <mrow> <mo>(</mo> <mi>&lambda;</mi> <msub> <mi>W</mi> <msub> <mi>PMI</mi> <mi>MRT</mi> </msub> </msub> <mo>+</mo> <mrow> <mo>(</mo> <mn>1</mn> <mo>-</mo> <mi>&lambda;</mi> <mo>)</mo> </mrow> <msub> <mi>W</mi> <msub> <mi>PMI</mi> <mi>ZF</mi> </msub> </msub> <mo>)</mo> </mrow> </mrow> </math>

wherein orth (·) represents the orthonormal operation performed on the input parameters, and λ ∈ [0, 1 ].

The step 104 may further specifically be:

the base station k obtains the maximum gain transmission information W by using the channel information from the served user to the base station k_MRT；

Base station k utilizes the H_IAnd said W_MRTObtaining interference minimized transmission information <math> <mrow> <msub> <mi>W</mi> <mi>ZF</mi> </msub> <mo>=</mo> <msubsup> <mi>&Pi;</mi> <msub> <mi>H</mi> <mi>I</mi> </msub> <mo>&perp;</mo> </msubsup> <msub> <mi>W</mi> <mi>MRT</mi> </msub> <mo>;</mo> </mrow> </math>

Base station k obtains precoding information W ═ orth (λ W)_MRT+(1-λ)W_ZF) And quantized into codewords in a codebook setThen, a code word is obtained

Corresponding index

Or ${\mathrm{PMI}}_W=\arg \underset{\mathrm{PMI}}{\max }\left|\right|{\left(W_{{\mathrm{PMI}}_W}\right)}^{H}W\left|\right|;$

Base station k sends PMI through downlink control channel_WTo the served user;

wherein,orth (-) denotes the orthonormal operation on the input parameters, λ ∈ [0, 1]]。

In this case, the step 105 specifically includes: user based on received PMI_WTo obtain the optimal precoding information

And adjusting the transmitted signal; the above-mentioned

For indexing PMI_WThe code word of (1).

Fig. 2 is a diagram illustrating a structure of a data transmission system of a MIMO system according to the present invention, and as shown in fig. 2, the data transmission system includes:

the information interaction unit is used for interacting the user scheduling information of the base stations in the base station set participating in the cooperation in the time frequency resource blocks through a network backbone or a backbone network or a special interface among the base stations, so that each base station obtains the user scheduling information of all adjacent cooperative base stations on each time frequency resource block;

the interference information calculation and transmission unit is used for obtaining interference source user information according to user scheduling information on a time-frequency resource block, obtaining interference information through measured channel information of the interference source user, and transmitting the interference information to a base station to which the interference source user belongs; the interference information may be channel information H from the interference source user to the base station, or an index corresponding to a codeword after quantizing the channel information H from the interference source user to the base station into the codeword in the codebook set

Or

The interference information formed by the first n columns of the right singular matrix or the eigenvector matrix obtained by decomposing the channel information H can also be interference information formed by quantizing the channel information H from the interference source user to the base station into code words in the codebook set, and then the indexes corresponding to the code words

Or

The equivalent interference information generating unit is used for receiving the interference information sent by other base stations in the cooperative base station set and forming equivalent interference information according to the interference information;

the optimal precoding information generating and sending unit is used for generating information about precoding on a time-frequency resource block by utilizing equivalent interference information and channel information from a user to the user under the base station, and sending the information to the adjusting unit;

and the adjusting unit is used for receiving the information about the precoding, obtaining the optimal precoding information and adjusting the sending signal by using the optimal precoding information.

The working principle of the data transmission system is as follows:

each base station in the base station set participating in the cooperation obtains user scheduling information of other base stations on each resource block from a network backbone or a backbone network or a special interface between the base stations by using the information interaction unit, and sends the user scheduling information to the interference information calculation and sending unit, the interference information calculation and sending unit obtains interference source user information on each time-frequency resource block according to the user scheduling information, obtains interference information according to measured channel information from the interference source user to the base station, and sends the interference information to an equivalent interference information generation unit of the base station to which the interference source user belongs; an equivalent interference information generating unit of a base station to which an interference source user belongs receives interference information sent by all adjacent cooperative base stations, finally equivalent interference information is formed, and the equivalent interference information is sent to a connected optimal precoding information generating and sending unit; the optimal precoding information generating and sending unit generates information about precoding on a time-frequency resource block by using equivalent interference information and channel information from a user to the optimal precoding information generating and sending unit under the base station, and sends the information about precoding to the adjusting unit of the interference source user, and the adjusting unit of the interference source user obtains the optimal precoding information by using the information about precoding to adjust a sending signal.

Fig. 3 shows a networking diagram of a data transmission system of a MIMO system according to an embodiment of the present invention, as shown in fig. 3:

three adjacent base stations BS1, BS2 and BS3 in a base station set participating in cooperation carry out cooperative data transmission, for a certain time-frequency resource block, the base stations BS1, BS2 and BS3 schedule users MS1, MS2 and MS3 respectively, user scheduling information is interacted through a backbone network or a network backbone or a special interface among the base stations, so that the BS1 obtains interference source users MS2 and MS3 which form interference on the cell, the BS2 obtains interference source users MS1 and MS3 which form interference on the cell, and the BS3 obtains interference source users MS1 and MS2 which form interference on the cell.

For more detailed explanation of the present invention, the following specific examples are the case where each cooperative base station serves only one user, but the present invention is also applicable to the case where a plurality of cooperative base stations and each cooperative base station serves a plurality of users at the same time.

Detailed description of the preferred embodiment 1

Base stations BS1, BS2 and BS3 schedule users MS1, MS2 and MS3 respectively, and interact user scheduling information and the number of data streams sent by the users respectively through a network backbone or a dedicated interface between backbone networks or base stations, so that base station BS1 knows that user MS1 will interfere with user MS2 and user MS3, base station BS2 knows that user MS2 will interfere with user MS1 and user MS3, and base station BS3 knows that user MS3 will interfere with user MS1 and user MS 2;

the base station BS1 measures the channel information H from three users MS1, MS2 and MS3 to the base station BS 3578 through the uplink pilot₁₁，H₁₂，H₁₃The base station BS2 measures the channel information H from three users MS1, MS2 and MS3 to itself through the uplink pilot₂₁，H₂₂，H₂₃The base station BS3 measures the channel information H from three users MS1, MS2 and MS3 to itself through the uplink pilot₃₁，H₃₂，H₃₃；

Base station BS1 pair H₁₂，H₁₃Respectively carrying out characteristic decomposition or singular value decomposition to obtain a characteristic vector matrix or a right singular matrix, and forming interference information V by partial or all columns of the characteristic vector matrix or the right singular matrix₁₂And V₁₃Respectively transmitting to a base station BS2 and a base station BS3 through a network backbone or a backbone network or a special interface between the base stations; base station BS2 pair H₂₁、H₂₃Respectively carrying out characteristic decomposition or singular value decomposition to obtain a characteristic vector matrix or a right singular matrix, and forming interference information V by partial or all columns of the characteristic vector matrix or the right singular matrix₂₁And V₂₃The data is transmitted to the base station BS1 and the base station BS3 through a network backbone or a backbone network or a special interface between the base stations; base station BS3 pair H₃₁、H₃₂Respectively carrying out characteristic decomposition or singular value decomposition to obtain a characteristic vector matrix or a right singular matrix, and forming interference information V by partial or all columns of the characteristic vector matrix or the right singular matrix₃₁And V₃₂Transmitted to base station BS1 and base station BS2 through a network backbone or backbone network or a dedicated interface between base stations.

Taking the BS1 and the MS1 served by the BS as an example, the following processes are performed:

the base station BS1 receives the interference information V corresponding to the user MS1₂₁And V₃₁Forming equivalent interference information H_I1[V₂₁V₃₁]；

The base station BS1 according to the channel information H from the user MS1 to the base station BS1₁₁Obtaining the maximum gain transmission information W_MRTAnd W is_MRTQuantized to code words in a predetermined codebook setObtaining a codeword

The corresponding index is as follows:or ${\mathrm{PMI}}_{\mathrm{MRT}}=\arg \underset{\mathrm{PMI}}{\max }\left|\right|{\left(W_{{\mathrm{PMI}}_{\mathrm{MRT}}}\right)}^H{H}_{11}\left|\right|;$

The base station BS1 transmits the channel information H from the user MS1 to the base station BS1₁₁Performing eigen decomposition or singular value decomposition, and forming a vector V according to the first n columns of the obtained eigenvector matrix or right singular matrix₁Computing interference minimized transmission information

Wherein n is determined by the base station based on the channel information H₁₁Decomposition decision of (1);

since one base station only serves one user on one time-frequency resource block in this embodiment, V₁＝W_MRTI.e. by

Base station BS1 transmits information W with minimized interference_ZFQuantized to code words in a predetermined codebook set

And obtain a codeword

Corresponding index

Or ${\mathrm{PMI}}_{\mathrm{ZF}}=\arg \underset{\mathrm{PMI}}{\max }\left|\right|{\left(W_{{\mathrm{PMI}}_{\mathrm{ZF}}}\right)}^H{W}_{\mathrm{ZF}}\left|\right|;$

The base station BS1 will index PMI_MRTAnd PMI_ZFTransmitted to the user MS1 through a downlink control channel;

user MS1 based on received PMI_MRTAnd PMI_ZFGet the index as PMI_MRTCode word of

And indexed as PMI_ZFCode word of

And obtaining the optimal precoding information for adjusting the transmitted signal by the following formula:

<math> <mrow> <mi>W</mi> <mo>=</mo> <mi>orth</mi> <mrow> <mo>(</mo> <mi>&lambda;</mi> <msub> <mi>W</mi> <msub> <mi>PMI</mi> <mi>MRT</mi> </msub> </msub> <mo>+</mo> <mrow> <mo>(</mo> <mn>1</mn> <mo>-</mo> <mi>&lambda;</mi> <mo>)</mo> </mrow> <msub> <mi>W</mi> <msub> <mi>PMI</mi> <mi>ZF</mi> </msub> </msub> <mo>)</mo> </mrow> </mrow> </math>

wherein orth (·) represents the orthonormal operation performed on the input parameters, λ is a real number, and λ ∈ [0, 1 ].

Likewise, base station BS2 and base station BS3 perform similar operations as base station BS1 and perform corresponding transmissions.

Specific example 2

Base stations BS1, BS2 and BS3 schedule users MS1, MS2 and MS3 respectively, and interact user scheduling information and the number of data streams sent by the users respectively through a network backbone or a dedicated interface between backbone networks or base stations, so that base station BS1 knows that user MS1 will interfere with user MS2 and user MS3, base station BS2 knows that user MS2 will interfere with user MS1 and user MS3, and base station BS3 knows that user MS3 will interfere with user MS1 and user MS 2;

the base station BS1 measures the channel information H from three users MS1, MS2 and MS3 to the base station BS 3578 through the uplink pilot₁₁，H₁₂，H₁₃The base station BS2 measures the channel information H from three users MS1, MS2 and MS3 to itself through the uplink pilot₂₁，H₂₂，H₂₃The base station BS3 measures the channel information H from three users MS1, MS2 and MS3 to itself through the uplink pilot₃₁，H₃₂，H₃₃；

Base station BS1 pair H₁₂，H₁₃Respectively carrying out characteristic decomposition or singular value decomposition, and according to the characteristic value or singular value distribution condition obtained after decomposition, converting H into H₁₂And H₁₃Respectively quantized as code words in a codebook set preset by the systemAnd

and codes are transmitted through a dedicated interface between the network backbone or backbone network or base stationsCharacter (Chinese character)

And

corresponding index

Or

OrTo base station BS2 and base station BS3, respectively; base station BS2 pair H₂₁、H₂₃Respectively carrying out characteristic decomposition or singular value decomposition, and according to the characteristic value or singular value distribution condition obtained after decomposition, converting H into H₂₁And H₂₃Quantisation to codewords in a codebook set

Andand the code words are transmitted through a special interface between the network backbone or backbone networks or base stations

And

corresponding index

Or

OrTo base station BS1 and base station BS3, respectively; base station BS3 pair H₃₁、H₃₂Respectively carrying out characteristic decomposition or singular value decomposition, and according to the characteristic value or singular value distribution condition obtained after decomposition, converting H into H₃₁And H₃₂Quantisation to codewords in a codebook set

And

and the code words are transmitted through a special interface between the network backbone or backbone networks or base stations

And

corresponding index

Or

Or

To base station BS1 and base station BS2, respectively.

Taking the BS1 and the MS1 served by the BS as an example, the following processes are performed:

the base station BS1 receives the interference information PMI corresponding to the user MS1₂₁And PMI₃₁Forming equivalent interference information

Wherein, theRepresenting index PMI in codebook set₂₁Corresponding code word, said

Representing index PMI in codebook set₃₁A corresponding codeword;

the base station BS1 according to the channel information H from the user MS1 to the base station BS1₁₁To obtain the maximum gain transmission information W_MRTAnd quantized to code words in a codebook set preset by the system

Then, a code word is obtained

The corresponding index is as follows:

or ${\mathrm{PMI}}_{\mathrm{MRT}}=\arg \underset{\mathrm{PMI}}{\max }\left|\right|{\left(W_{{\mathrm{PMI}}_{\mathrm{MRT}}}\right)}^H{H}_{11}\left|\right|;$

The base station BS1 transmits the channel information H from the user MS1 to the base station BS1₁₁Performing eigen decomposition or singular value decomposition, and forming a matrix or vector V according to the first n columns of the obtained eigenvector matrix or right singular matrix₁Computing interference minimized transmission information

Wherein n is determined by the base station based on the channel information H₁₁Indicates the number of data streams transmitted by the subscriber MS 1;since one base station only serves one user on one time-frequency resource block in this embodiment, V₁＝W_MRTI.e. by <math> <mrow> <msub> <mi>W</mi> <mi>ZF</mi> </msub> <mo>=</mo> <msubsup> <mi>&Pi;</mi> <msub> <mi>H</mi> <mrow> <mi>I</mi> <mn>1</mn> </mrow> </msub> <mo>&perp;</mo> </msubsup> <msub> <mi>W</mi> <mi>MRT</mi> </msub> <mo>;</mo> </mrow> </math>

Base station BS1 transmits information W with minimized interference_ZFQuantisation to codewords in codebook set

And obtain a codeword

Corresponding index

Or ${\mathrm{PMI}}_{\mathrm{ZF}}=\arg \underset{\mathrm{PMI}}{\max }\left|\right|{\left(W_{{\mathrm{PMI}}_{\mathrm{ZF}}}\right)}^H{W}_{\mathrm{ZF}}\left|\right|;$

The base station BS1 will index PMI_MRTAnd PMI_ZFTransmitted to the user MS1 through a downlink control channel;

user MS1 based on received PMI_MRTAnd PMI_ZFGet the index as PMI_MRTCode word of

And indexed as PMI_ZFCode word ofAnd obtaining the optimal precoding information for adjusting the transmitted signal by the following formula:

<math> <mrow> <mi>W</mi> <mo>=</mo> <mi>orth</mi> <mrow> <mo>(</mo> <mi>&lambda;</mi> <msub> <mi>W</mi> <msub> <mi>PMI</mi> <mi>MRT</mi> </msub> </msub> <mo>+</mo> <mrow> <mo>(</mo> <mn>1</mn> <mo>-</mo> <mi>&lambda;</mi> <mo>)</mo> </mrow> <msub> <mi>W</mi> <msub> <mi>PMI</mi> <mi>ZF</mi> </msub> </msub> <mo>)</mo> </mrow> </mrow> </math>

wherein orth (·) represents the orthonormal operation performed on the input parameters, λ is a real number, and λ ∈ [0, 1 ].

Likewise, base station BS2 and base station BS3 perform similar operations as base station BS1 and perform corresponding transmissions.

Specific example 3

Base stations BS1, BS2 and BS3 schedule users MS1, MS2 and MS3 respectively, and interact user scheduling information and the number of data streams sent by the users respectively through a network backbone or a dedicated interface between backbone networks or base stations, so that base station BS1 knows that user MS1 will interfere with user MS2 and user MS3, base station BS2 knows that user MS2 will interfere with user MS1 and user MS3, and base station BS3 knows that user MS3 will interfere with user MS1 and user MS 2;

the base station BS1 measures the channel information H from three users MS1, MS2 and MS3 to the base station BS 3578 through the uplink pilot₁₁，H₁₂，H₁₃The base station BS2 measures the channel information H from three users MS1, MS2 and MS3 to itself through the uplink pilot₂₁，H₂₂，H₂₃The base station BS3 measures the channel information H from three users MS1, MS2 and MS3 to itself through the uplink pilot₃₁，H₃₂，H₃₃；

Base station BS1 pair H₁₂，H₁₃Respectively carrying out characteristic decomposition or singular value decomposition, and according to the characteristic value or singular value distribution condition obtained after decomposition, converting H into H₁₂And H₁₃Quantizing to code words in a system preset codebook set

And

and the code words are transmitted through a special interface between the network backbone or backbone networks or base stations

And

corresponding index

Or

Or

To base station BS2 and base station BS3, respectively;

base station BS2 pair H₂₁、H₂₃Respectively carrying out characteristic decomposition or singular value decomposition, and according to the characteristic value or singular value distribution condition obtained after decomposition, converting H into H₂₁And H₂₃Quantisation to codewords in a codebook setAnd

and the code words are transmitted through a special interface between the network backbone or backbone networks or base stations

And

corresponding index

Or

Or

To base station BS1 and base station BS3, respectively;

base station BS3 pair H₃₁、H₃₂Respectively carrying out characteristic decomposition or singular value decomposition, and according to the characteristic value or singular value distribution condition obtained after decomposition, converting H into H₃₁And H₃₂Quantisation to codewords in a codebook set

And

and the code words are transmitted through a special interface between the network backbone or backbone networks or base stations

Andcorresponding index

Or

OrTo base station BS1 and base station BS2, respectively;

taking the BS1 and the MS1 served by the BS as an example, the following processes are performed:

the base station BS1 receives the interference information PMI corresponding to the user MS1₂₁And PMI₃₁Forming equivalent interference information

Wherein, the

Representing index PMI in codebook set₂₁Corresponding code word, said

Representing index PMI in codebook set₃₁A corresponding codeword;

base station BS1 according to user MS1 to base station BS1 channel informationH₁₁To obtain the maximum gain transmission information W_MRTAnd quantized into codewords in a codebook set

Then, a code word is obtained

The corresponding index is as follows:or

The base station BS1 transmits the channel information H from the user MS1 to the base station BS1₁₁Performing eigen decomposition or singular value decomposition, and forming a matrix or vector V according to the first n columns of the obtained eigenvector matrix or right singular matrix₁Computing interference minimized transmission information

Wherein n is determined by the base station based on the channel information H₁₁Indicates the number of data streams transmitted by the subscriber MS 1;

base station BS1 transmits information W with minimized interference_ZFQuantizing code words in codebook set preset by systemAnd obtain a codeword

Corresponding index

Or ${\mathrm{PMI}}_{\mathrm{ZF}}=\arg \underset{\mathrm{PMI}}{\max }\left|\right|{\left(W_{{\mathrm{PMI}}_{\mathrm{ZF}}}\right)}^H{W}_{\mathrm{ZF}}\left|\right|;$

The base station BS1 will index PMI_MRTAnd PMI_ZFTransmitted to the user MS1 through a downlink control channel;

user MS1 based on received PMI_MRTAnd PMI_ZFGet the index as PMI_MRTCode word of

And indexed as PMI_ZFCode word of

And obtaining the optimal precoding information for adjusting the transmitted signal by the following formula:

<math> <mrow> <mi>W</mi> <mo>=</mo> <mi>orth</mi> <mrow> <mo>(</mo> <mi>&lambda;</mi> <msub> <mi>W</mi> <msub> <mi>PMI</mi> <mi>MRT</mi> </msub> </msub> <mo>+</mo> <mrow> <mo>(</mo> <mn>1</mn> <mo>-</mo> <mi>&lambda;</mi> <mo>)</mo> </mrow> <msub> <mi>W</mi> <msub> <mi>PMI</mi> <mi>ZF</mi> </msub> </msub> <mo>)</mo> </mrow> </mrow> </math>

wherein orth (·) represents the orthonormal operation performed on the input parameters, λ is a real number, and λ ∈ [0, 1 ].

Likewise, base station BS2 and base station BS3 perform similar operations as base station BS1 and perform corresponding transmissions.

Specific example 4

Base stations BS1, BS2 and BS3 schedule users MS1, MS2 and MS3 respectively, and interact user scheduling information and the number of data streams sent by the users respectively through a network backbone or a dedicated interface between backbone networks or base stations, so that base station BS1 knows that user MS1 will interfere with user MS2 and user MS3, base station BS2 knows that user MS2 will interfere with user MS1 and user MS3, and base station BS3 knows that user MS3 will interfere with user MS1 and user MS 2;

the base station BS1 measures the channel information H from three users MS1, MS2 and MS3 to the base station BS 3578 through the uplink pilot₁₁，H₁₂，H₁₃The base station BS2 measures the channel information H from three users MS1, MS2 and MS3 to itself through the uplink pilot₂₁，H₂₂，H₂₃The base station BS3 measures the channel information H from three users MS1, MS2 and MS3 to itself through the uplink pilot₃₁，H₃₂，H₃₃；

Base station BS1 pair H₁₂，H₁₃Respectively carrying out characteristic decomposition or singular value decomposition, and according to the characteristic value or singular value distribution condition obtained after decomposition, converting H into H₁₂And H₁₃Quantisation to codewords in a codebook set

Andand the code words are transmitted through a special interface between the network backbone or backbone networks or base stations

And

corresponding index

Or

Or

To base station BS2 and base station BS3, respectively;

base station BS2 pair H₂₁、H₂₃Respectively carrying out characteristic decomposition or singular value decomposition, and according to the characteristic value or singular value distribution condition obtained after decomposition, converting H into H₂₁And H₂₃Quantisation to codewords in a codebook set

And

and the code words are transmitted through a special interface between the network backbone or backbone networks or base stations

And

corresponding index

Or

Or

To base station BS1 and base station BS3, respectively;

base station BS3 pair H₃₁、H₃₂Respectively carrying out characteristic decomposition or singular value decomposition, and according to the characteristic value or singular value distribution condition obtained after decomposition, converting H into H₃₁And H₃₂Quantisation to codewords in a codebook set

And

and the code words are transmitted through a special interface between the network backbone or backbone networks or base stations

Andcorresponding indexOr

Or

To base station BS1 and base station BS2, respectively;

taking the BS1 and the MS1 served by the BS as an example, the following processes are performed:

the base station BS1 receives the interference information PMI corresponding to the user MS1₂₁And PMI₃₁Forming equivalent interference information

Wherein, the

Representing index PMI in codebook set₂₁Corresponding code word, said

Representing index PMI in codebook set₃₁A corresponding codeword;

the base station BS1 according to the channel information H from the user MS1 to the base station BS1₁₁To obtain the maximum gain transmission information W_MRT(ii) a Wherein the maximized gain transmits information W_MRTCan pass throughOr

The calculation is carried out according to the calculation,

then

The base station BS1 utilizes the equivalent interference information H_I1And W_MRTComputing interference minimized transmission information

Wherein n is determined by the base station based on the channel information H₁₁Indicates the number of data streams transmitted by the subscriber MS 1;

base station BS1 uses W_MRTAnd W_ZFCalculating optimal precoding information W ═ orth (λ W)_MRT+(1-λ)W_ZF) Wherein orth (·) represents that the input parameter is subjected to standard orthogonalization operation, λ is a real number, and λ is more than or equal to 0 and less than or equal to 1;

base station BS1 quantizes W to codewords in codebook set

And combining the code words

Corresponding index

Or

Transmitted to the user MS1 through a downlink control channel;

MS1 is obtaining index PMI_WThen, taking out PMI from codebook set_WCorresponding code wordObtaining optimal precoding information

Then precoding data S to be transmitted to obtain W' S; wherein, W_PMIFor indexing PMI_WA corresponding codeword.

Likewise, base station BS2 and base station BS3 perform similar operations as base station BS1 and perform corresponding transmissions.

Specific example 5

For a certain resource block to be scheduled, the base station BS1, BS2, and BS3 schedule the user MS1, MS2, and MS3, respectively, and interact the user scheduling information and the number of data streams sent by the user through a dedicated interface between a network backbone or backbone network or base stations, respectively, so that the base station BS1 knows that the user MS1 will interfere with the user MS2 and the user MS3, the base station BS2 knows that the user MS2 will interfere with the user MS1 and the user MS3, and the base station BS3 knows that the user MS3 will interfere with the user MS1 and the user MS 2;

the base station BS1 measures the channel information H from three users MS1, MS2 and MS3 to the base station BS 3578 through the uplink pilot₁₁，H₁₂，H₁₃Base station BS2 via uplinkPilot measures channel information H from three users MS1, MS2 and MS3 to the pilot₂₁，H₂₂，H₂₃The base station BS3 measures the channel information H from three users MS1, MS2 and MS3 to itself through the uplink pilot₃₁，H₃₂，H₃₃；

Base station BS1 will H₁₂，H₁₃The data are respectively transmitted to a base station BS2 and a base station BS3 through a backbone network or a special interface between backbone networks or base stations;

base station BS2 will H₂₁，H₂₃The data are respectively transmitted to a base station BS1 and a base station BS3 through a backbone network or a special interface between backbone networks or base stations;

base station BS3 will H₃₁，H₃₂The data are respectively transmitted to a base station BS1 and a base station BS2 through a backbone network or a special interface between backbone networks or base stations;

for the base station BS1 and its served user MS1, the following processing is performed:

the base station BS1 receives the interference information H corresponding to the MS1₁₂And H₁₂Forming equivalent interference information: h_I1＝[H₂₁H₃₁]；

The base station BS1 utilizes the channel information H from MS1 to the base station₁₁To obtain the maximum gain transmission information W_MRTAnd finding out the code word of the maximum gain transmission information in the codebook set preset by the system

Obtaining a codeword

Corresponding index

Or ${\mathrm{PMI}}_{\mathrm{MRT}}=\arg \underset{\mathrm{PMI}}{\max }\left|\right|{\left(W_{{\mathrm{PMI}}_{\mathrm{MRT}}}\right)}^H{H}_{11}\left|\right|;$

Base station BS1 will H₁₁Singular value decomposition is carried out, and the first n columns of decomposed right singular vectors are taken to form a matrix or a vector V₁Using V₁To obtain

Wherein n is determined by the base station based on the channel information H₁₁Indicates the number of data streams transmitted by the subscriber MS 1;

the base station BS1 will minimize the interference transmission information W_ZFQuantizing to code words in a system preset codebook set

Code word

Corresponding index isOr ${\mathrm{PMI}}_{\mathrm{ZF}}=\arg \underset{\mathrm{PMI}}{\max }\left|\right|{\left(W_{{\mathrm{PMI}}_{\mathrm{ZF}}}\right)}^H{W}_{\mathrm{ZF}}\left|\right|.$

The base station BS1 will index PMI_MRTAnd PMI_ZFUsing a downlink control channel for transmission to the MS 1.

MS1 is obtaining index PMI_MRTAnd PMI_ZFAnd then, calculating the optimal precoding information by using a formula preset by the system:

wherein

Indicating PMI as index in preset codebook_MRTThe code words of (a) are used,

indicating PMI as index in preset codebook_ZFThe code word of (1). Lambda is a real number, and lambda is more than or equal to 0 and less than or equal to 1.

Likewise, base station BS2 and base station BS3 perform similar operations as base station BS1 and perform corresponding transmissions.

Specific example 6

For a certain resource block to be scheduled, the BS1, BS2, and BS3 schedule users MS1, MS2, and MS3, respectively, and the base stations BS1, BS2, and BS3 interact the scheduling information with the number of data streams sent by the users through a backbone network or a dedicated interface between backbones of the network or between the base stations, so that the BS1 knows that the MS1 will interfere with the MS2 and the MS3, the BS2 knows that the MS2 will interfere with the MS1 and the MS3, and the BS3 knows that the MS3 will interfere with the MS1 and the MS 2.

The base station BS1 measures the channel information H from three users MS1, MS2 and MS3 to the base station BS 3578 through the uplink pilot₁₁，H₁₂，H₁₃The base station BS2 measures the channels from three users MS1, MS2 and MS3 to itself through uplink pilotInformation H₂₁，H₂₂，H₂₃The base station BS3 measures the channel information H from three users MS1, MS2 and MS3 to itself through the uplink pilot₃₁，H₃₂，H₃₃；

BS1 for H₁₂，H₁₃Performing eigenvalue or singular value decomposition, respectively, by BS1 based on H₁₂，H₁₃Distribution of characteristic values or singular values of H₁₂，H₁₃Quantizing to code words in a system preset codebook set

And

and obtain the corresponding index

Or

Or

The base station BS1 will index PMI₁₂And PMI₁₃The data are respectively transmitted to a base station BS2 and a base station BS3 through a backbone network or a special interface between backbone networks or base stations;

BS2 according to H₂₁And H₂₃Performing eigenvalue or singular value decomposition, respectively, by BS2 based on H₂₁And H₂₃Distribution of characteristic values or singular values of H₂₁And H₂₃Quantizing to code words in a system preset codebook set

And

and obtain the corresponding index

Or

Or

The base station BS2 will index PMI₂₁And PMI₂₃The data are respectively transmitted to a base station BS1 and a base station BS3 through a backbone network or a special interface between backbone networks or base stations;

BS3 according to H₃₁And H₃₂Performing eigenvalue or singular value decomposition, respectively, by BS3 based on H₃₁And H₃₂Distribution of characteristic values or singular values of H₃₁And H₃₂Quantizing to code words in a system preset codebook set

And

and obtain the corresponding index

Or

OrThe base station BS2 will index PMI₃₁And PMI₃₂The data is transmitted to the base station BS1 and the base station BS3 through a backbone network or a network backbone or a special interface between the base stations;

taking the BS1 and the MS1 served by the BS as an example, the following processes are performed:

the base station BS1 receives the interference information PMI corresponding to the MS1₂₁And PMI₃₁Forming equivalent interference information

WhereinIndicates that index in preset codebook set of codebook system is PMI₂₁The corresponding code word or words are then used,indicates that index in preset codebook set of codebook system is PMI₃₁A corresponding codeword.

The base station BS1 utilizes the MS1 to the channel H of the base station₁₁Calculating maximum gain transmission information

Wherein the maximized gain transmits information W_MRTCan pass through

Or

The calculation is carried out according to the calculation,

then

The base station BS1 utilizes the equivalent interference information H_I1And W_MRTComputing interference minimized transmission information

Wherein n is determined by the base station according to the channelInformation H₁₁Indicates the number of data streams transmitted by the subscriber MS 1;

base station BS1 uses W_MRTAnd W_ZFCalculating optimal precoding information W ═ orth (λ W)_MRT+(1-λ)W_ZF) Wherein

Indicating PMI as index in preset codebook_MRTThe code words of (a) are used,

indicating PMI as index in preset codebook_ZFThe code word of (1). Lambda is a real number, and lambda is more than or equal to 0 and less than or equal to 1.

The base station BS1 quantizes W into code words in a codebook set preset by the system

And will correspond to the index

And to the user MS1 via a downlink control channel.

MS1 is obtaining index PMI_WThen, taking out PMI from codebook set_WCorresponding code word

Obtaining optimal precoding information

Then precoding data S to be transmitted to obtain W' S; wherein,for indexing PMI_WA corresponding codeword.

Similarly, BS2 and BS3 perform similar operations to accomplish corresponding transmissions.

In summary, the present invention provides a multi-base station information interaction mechanism and a data precoding mechanism, so that only simple information interaction is required for the base stations participating in the cooperation, most interference can be suppressed, and the transmission quality of uplink data is improved.

Although the present invention has been described in detail hereinabove, the present invention is not limited thereto, and various modifications can be made by those skilled in the art in light of the principle of the present invention. Thus, modifications made in accordance with the principles of the present invention should be understood to fall within the scope of the present invention.

Claims (20)

1. A data transmission method of a mimo MIM0 system, comprising:

A) each base station in the base station set participating in the cooperation interacts user scheduling information on the time-frequency resource blocks through a network backbone or a backbone network or a special interface between the base stations;

B) each base station in the base station set participating in the cooperation acquires interference source user information according to user scheduling information on a time-frequency resource block, acquires the interference information by measuring channel information between an interference source user and the base station, and sends the interference information to the base station to which the interference source user belongs;

C) each base station receives interference information sent by other base stations in the cooperative base station set, and equivalent interference information is formed according to the interference information;

D) each base station obtains information about precoding on a time-frequency resource block by using equivalent interference information and channel information from a served user to the base station, and sends the information to the served user;

E) and the user obtains optimal precoding information according to the received information about precoding, and adjusts the sending signal by utilizing the optimal precoding information.

2. The data transmission method according to claim 1, wherein the step B) is specifically:

each base station in the base station set participating in the cooperation acquires information of an interference source user according to user scheduling information of other base stations on a time-frequency resource block;

each base station in the cooperative base station set carries out singular value decomposition or pair (H) on the channel information H from the interference source user to the base station^HH or E ((H)^HH) Performing characteristic decomposition to obtain a right singular matrix or a characteristic vector matrix V;

extracting the first n columns of vectors of V to generate interference information VⁿSending the interference information to a base station K to which the interference source user belongs;

where n is determined by the base station based on the decomposition of the channel information H.

3. The data transmission method according to claim 2, wherein in the step C), the equivalent interference information is:

<math> <mrow> <msub> <mi>H</mi> <mi>I</mi> </msub> <mo>=</mo> <mfenced open='[' close=']'> <mtable> <mtr> <mtd> <msubsup> <mi>V</mi> <mrow> <mi>j</mi> <mn>1</mn> </mrow> <mi>n</mi> </msubsup> </mtd> <mtd> <mo>&CenterDot;</mo> <mo>&CenterDot;</mo> <mo>&CenterDot;</mo> </mtd> <mtd> <mo>&CenterDot;</mo> <mo>&CenterDot;</mo> <mo>&CenterDot;</mo> </mtd> <mtd> <msubsup> <mi>V</mi> <mi>jm</mi> <mi>n</mi> </msubsup> </mtd> </mtr> </mtable> </mfenced> </mrow> </math>

where m is a user set scheduled by a base station j on the same time-frequency resource block, j ≠ k, j ═ 1, …, N.

4. The data transmission method according to claim 1, wherein the step B) is specifically:

each base station in the base station set participating in the cooperation acquires information of an interference source user according to user scheduling information of other base stations on a time-frequency resource block;

each base station in the cooperative base station set quantizes the channel information H from the interference source user to the base station into a code word in the codebook set

And according to the code wordA corresponding index is obtained, and the index is obtained, $\mathrm{PMI}=\arg \underset{\mathrm{PMI}}{\max }\left|\right|{\left(H\right)}^H{W}_{\mathrm{PMI}}^n\left|\right|$ or $\mathrm{PMI}=\arg \underset{\mathrm{PMI}}{\max }\left|\right|{\left(W_{\mathrm{PMI}}^n\right)}^{H}H\left|\right|;$

Transmitting the index PMI to a base station k to which an interference source user belongs through a backbone network connected with the base stations or a network backbone or a special interface between the base stations;

where n is determined by the base station based on the channel information H.

5. The data transmission method according to claim 4, wherein in the step C), the equivalent interference information is:

<math> <mrow> <msub> <mi>H</mi> <mi>I</mi> </msub> <mo>=</mo> <mfenced open='[' close=']'> <mtable> <mtr> <mtd> <msubsup> <mi>W</mi> <msub> <mi>PMI</mi> <mrow> <mi>j</mi> <mn>1</mn> </mrow> </msub> <mi>n</mi> </msubsup> </mtd> <mtd> <mo>&CenterDot;</mo> <mo>&CenterDot;</mo> <mo>&CenterDot;</mo> </mtd> <mtd> <mo>&CenterDot;</mo> <mo>&CenterDot;</mo> <mo>&CenterDot;</mo> </mtd> <mtd> <msubsup> <mi>W</mi> <msub> <mi>PMI</mi> <mi>jm</mi> </msub> <mi>n</mi> </msubsup> </mtd> </mtr> </mtable> </mfenced> </mrow> </math>

where m is a user set scheduled by a base station j on the same time-frequency resource block, j ≠ k, j ═ 1, …, N.

6. The data transmission method according to claim 1, wherein the step B) is specifically:

each base station in the base station set participating in the cooperation acquires information of an interference source user according to user scheduling information of other base stations on a time-frequency resource block;

and each base station in the cooperative base station set transmits the channel information H from the interference source user to the base station K to which the interference source user belongs through a backbone network connected with the base stations or a network backbone or a special interface between the base stations.

7. The data transmission method according to claim 6, wherein in the step C), the equivalent interference information is:

<math> <mrow> <msub> <mi>H</mi> <mi>I</mi> </msub> <mo>=</mo> <mfenced open='[' close=']'> <mtable> <mtr> <mtd> <msub> <mi>H</mi> <mrow> <mi>j</mi> <mn>1</mn> </mrow> </msub> </mtd> <mtd> <mo>&CenterDot;</mo> <mo>&CenterDot;</mo> <mo>&CenterDot;</mo> </mtd> <mtd> <mo>&CenterDot;</mo> <mo>&CenterDot;</mo> <mo>&CenterDot;</mo> </mtd> <mtd> <msub> <mi>H</mi> <mi>jm</mi> </msub> </mtd> </mtr> </mtable> </mfenced> </mrow> </math>

where m is a user set scheduled by a base station j on the same time-frequency resource block, j ≠ k, j ═ 1, …, N.

8. The data transmission method according to any one of claims 1 to 7, wherein the step D) is specifically:

the base station k obtains the maximum gain transmission information W by using the channel information from the served user to the base station k_MRT；

Base station k utilizes the H_IAnd said W_MRTObtaining interference minimized transmission information <math> <mrow> <msub> <mi>W</mi> <mi>ZF</mi> </msub> <mo>=</mo> <msubsup> <mi>&Pi;</mi> <msub> <mi>H</mi> <mi>I</mi> </msub> <mo>&perp;</mo> </msubsup> <msub> <mi>W</mi> <mi>MRT</mi> </msub> <mo>;</mo> </mrow> </math>

Base station k obtains optimal precoding information W ═ orth (λ W) of serving user_MRT+(1-λ)W_ZF) And sending the data to the interfered user through a downlink control channel;

wherein,

orth (-) denotes the orthonormal operation on the input parameters, λ ∈ [0, 1]]。

9. The data transmission method according to any one of claims 1 to 7, wherein the step D) is specifically:

the base station k obtains the maximum gain transmission information W by using the channel information from the served user to the base station k_MRTAnd quantized into codewords in a codebook set

Then, a code word is obtained

Corresponding index ${\mathrm{PMI}}_{\mathrm{MRT}}=\arg \underset{\mathrm{PMI}}{\max }\left|\right|{\left(W_{\mathrm{MRT}}\right)}^H{W}_{{\mathrm{PMI}}_{\mathrm{MRT}}}\left|\right|$ Or ${\mathrm{PMI}}_{\mathrm{MRT}}=\arg \underset{\mathrm{PMI}}{\max }\left|\right|{\left(W_{{\mathrm{PMI}}_{\mathrm{MRT}}}\right)}^H{W}_{\mathrm{MRT}}\left|\right|;$

Base station k utilizes the H_IAnd said W_MRTObtaining interference minimized transmission information

And quantized into codewords in a codebook set

Then, a code word is obtained

Corresponding index

Or

Base station sends PMI through downlink control channel_MRTAnd PMI_ZFTransmitting to the user under the base station;

wherein, <math> <mrow> <msubsup> <mi>&Pi;</mi> <msub> <mi>H</mi> <mi>I</mi> </msub> <mo>&perp;</mo> </msubsup> <mo>=</mo> <msub> <mrow> <mi>I</mi> <mo>-</mo> <mi>H</mi> </mrow> <mi>I</mi> </msub> <msup> <mrow> <mo>(</mo> <msubsup> <mi>H</mi> <mi>I</mi> <mi>H</mi> </msubsup> <msub> <mi>H</mi> <mi>I</mi> </msub> <mo>)</mo> </mrow> <mrow> <mo>-</mo> <mn>1</mn> </mrow> </msup> <msubsup> <mi>H</mi> <mi>I</mi> <mi>H</mi> </msubsup> <mo>.</mo> </mrow> </math>

10. the data transmission method according to claim 9, wherein the step E) is specifically: user based on received PMI_MRTAnd PMI_ZFGet the index as PMI_MRTCode word of

And indexed as PMI_ZFCode word of

And obtaining the optimal precoding information for adjusting the transmission signal by the following formula:

<math> <mrow> <mi>W</mi> <mo>=</mo> <mi>orth</mi> <mrow> <mo>(</mo> <mi>&lambda;</mi> <msub> <mi>W</mi> <msub> <mi>PMI</mi> <mi>MRT</mi> </msub> </msub> <mo>+</mo> <mrow> <mo>(</mo> <mn>1</mn> <mo>-</mo> <mi>&lambda;</mi> <mo>)</mo> </mrow> <msub> <mi>W</mi> <msub> <mi>PMI</mi> <mi>ZF</mi> </msub> </msub> <mo>)</mo> </mrow> </mrow> </math>

wherein orth (·) represents the orthonormal operation performed on the input parameters, and λ ∈ [0, 1 ].

11. The data transmission method according to any one of claims 1 to 7, wherein the step D) is specifically:

the base station K obtains the maximum gain transmission information W by utilizing the channel information from the served user to the base station K_MRT；

Base station K utilizes the H_IAnd said W_MRTObtaining interference minimized transmission information <math> <mrow> <msub> <mi>W</mi> <mi>ZF</mi> </msub> <mo>=</mo> <msubsup> <mi>&Pi;</mi> <msub> <mi>H</mi> <mi>I</mi> </msub> <mo>&perp;</mo> </msubsup> <msub> <mi>W</mi> <mi>MRT</mi> </msub> <mo>;</mo> </mrow> </math>

Base station K obtains precoding information W ═ orth (λ W)_MRT+(1-λ)W_ZF) And quantized into codewords in a codebook set

Then, a code word is obtainedCorresponding index

Or ${\mathrm{PMI}}_W=\arg \underset{\mathrm{PMI}}{\max }\left|\right|{\left(W_{{\mathrm{PMI}}_W}\right)}^{H}W\left|\right|;$

Base station K indexes PMI through downlink control channel_WTo the served user;

wherein,

orth (-) denotes the orthonormal operation on the input parameters, λ ∈ [0, 1]]。

12. The data transmission method according to claim 11, wherein the step E) is specifically:

the user served by the base station K receives the PMI_WObtaining optimal precoding information for adjusting a transmitted signal

To which it belongsIs indexed as PMI_WThe code word of (1).

13. The data transmission method according to claim 1, wherein the step B) is specifically:

each base station in the base station set participating in the cooperation acquires information of an interference source user according to user scheduling information of other base stations on a time-frequency resource block;

each base station in the base station set participating in cooperation quantizes channel information H from interference source user to itself into code words in the codebook set W

And according to the code word

Get the corresponding index $\mathrm{PMI}=\arg \underset{\mathrm{PMI}}{\min }\left|\right|{\left(H\right)}^H{W}_{\mathrm{PMI}}^n\left|\right|$ Or $\mathrm{PMI}=\arg \underset{\mathrm{PMI}}{\min }\left|\right|{\left(W_{\mathrm{PMI}}^n\right)}^{H}H\left|\right|;$

Transmitting the index PMI to a base station k to which an interference source user belongs through a backbone network connected with the base stations or a network backbone or a special interface between the base stations;

where n is determined by the base station based on the decomposition of the channel information H.

14. The data transmission method according to claim 13, wherein in the step C), the equivalent interference information is:

<math> <mrow> <msub> <mi>H</mi> <mi>I</mi> </msub> <mo>=</mo> <mfenced open='[' close=']'> <mtable> <mtr> <mtd> <msubsup> <mi>W</mi> <msub> <mi>PMI</mi> <mrow> <mi>j</mi> <mn>1</mn> </mrow> </msub> <mi>n</mi> </msubsup> </mtd> <mtd> <mo>&CenterDot;</mo> <mo>&CenterDot;</mo> <mo>&CenterDot;</mo> </mtd> <mtd> <mo>&CenterDot;</mo> <mo>&CenterDot;</mo> <mo>&CenterDot;</mo> </mtd> <mtd> <msubsup> <mi>W</mi> <msub> <mi>PMI</mi> <mi>jm</mi> </msub> <mi>n</mi> </msubsup> </mtd> </mtr> </mtable> </mfenced> </mrow> </math>

where m is a user set scheduled by a base station j on the same time-frequency resource block, j ≠ k, j ═ 1, …, N.

15. The data transmission method according to any one of claims 1, 13, and 14, wherein the step D) is specifically:

the base station K obtains the maximum gain transmission information W by utilizing the channel information from the served user to the base station K_MRT；

Base station K utilizes the H_IAnd said W_MRTObtaining interference minimized transmission information <math> <mrow> <msub> <mi>W</mi> <mi>ZF</mi> </msub> <mo>=</mo> <msubsup> <mi>&Pi;</mi> <msub> <mi>H</mi> <mi>I</mi> </msub> <mo>&perp;</mo> </msubsup> <msub> <mi>W</mi> <mi>MRT</mi> </msub> <mo>;</mo> </mrow> </math>

Base station k obtains optimal precoding information W ═ orth (λ W) for served users_MRT+(1-λ)W_ZF) And sending the data to the served user through a downlink control channel;

wherein,

orth (-) denotes the orthonormal operation on the input parameters, λ ∈ [0, 1]]。

16. The data transmission method according to any one of claims 1, 13, and 14, wherein the step D) is specifically:

the base station K obtains the maximum gain transmission information W by utilizing the channel information from the user to the base station K_MRTAnd quantized into codewords in a codebook set

Then, a code word is obtained

Corresponding index ${\mathrm{PMI}}_{\mathrm{MRT}}=\arg \underset{\mathrm{PMI}}{\max }\left|\right|{\left(W_{\mathrm{MRT}}\right)}^H{W}_{{\mathrm{PMI}}_{\mathrm{MRT}}}\left|\right|$ Or ${\mathrm{PMI}}_{\mathrm{MRT}}=\arg \underset{\mathrm{PMI}}{\max }\left|\right|{\left(W_{{\mathrm{PMI}}_{\mathrm{MRT}}}\right)}^H{W}_{\mathrm{MRT}}\left|\right|;$

Base station K utilizes the H_IAnd said W_MRTObtaining interference minimized transmission information

And quantized into codewords in a codebook set

Then, a code word is obtained

Corresponding index

Or

PMI of base station k to which user belongs through downlink control channel_MRTAnd PMI_ZFTransmitting to the user;

wherein, <math> <mrow> <msubsup> <mi>&Pi;</mi> <msub> <mi>H</mi> <mi>I</mi> </msub> <mo>&perp;</mo> </msubsup> <mo>=</mo> <msub> <mi>H</mi> <mi>I</mi> </msub> <msup> <mrow> <mo>(</mo> <msubsup> <mi>H</mi> <mi>I</mi> <mi>H</mi> </msubsup> <msub> <mi>H</mi> <mi>I</mi> </msub> <mo>)</mo> </mrow> <mrow> <mo>-</mo> <mn>1</mn> </mrow> </msup> <msubsup> <mi>H</mi> <mi>I</mi> <mi>H</mi> </msubsup> <mo>.</mo> </mrow> </math>

17. the data transmission method according to claim 16, wherein the step E) is specifically:

user based on received PMI_MRTAnd PMI_ZFGet the index as PMI_MRTCode word of

And indexed as PMI_ZFCode word of

And obtaining the optimal precoding information for adjusting the transmission signal by the following formula:

<math> <mrow> <mi>W</mi> <mo>=</mo> <mi>orth</mi> <mrow> <mo>(</mo> <mi>&lambda;</mi> <msub> <mi>W</mi> <msub> <mi>PMI</mi> <mi>MRT</mi> </msub> </msub> <mo>+</mo> <mrow> <mo>(</mo> <mn>1</mn> <mo>-</mo> <mi>&lambda;</mi> <mo>)</mo> </mrow> <msub> <mi>W</mi> <msub> <mi>PMI</mi> <mi>ZF</mi> </msub> </msub> <mo>)</mo> </mrow> </mrow> </math>

wherein orth (·) represents the orthonormal operation performed on the input parameters, and λ ∈ [0, 1 ].

18. The data transmission method according to any one of claims 1, 13, and 14, wherein the step D) is specifically:

the base station K utilizes the channel information from the served users to itself,obtaining maximum gain transmission information W_MRT(ii) a Base station K utilizes the H_IAnd said W_MRTObtaining interference minimized transmission information <math> <mrow> <msub> <mi>W</mi> <mi>ZF</mi> </msub> <mo>=</mo> <msubsup> <mi>&Pi;</mi> <msub> <mi>H</mi> <mi>I</mi> </msub> <mo>&perp;</mo> </msubsup> <msub> <mi>W</mi> <mi>MRT</mi> </msub> <mo>;</mo> </mrow> </math>

Base station k obtains precoding information W ═ orth (λ W)_MRT+(1-λ)W_ZF) And quantized into codewords in a codebook set

Then, a code word is obtained

Corresponding index

Or ${\mathrm{PMI}}_W=\arg \underset{\mathrm{PMI}}{\max }\left|\right|{\left(W_{{\mathrm{PMI}}_W}\right)}^{H}W\left|\right|;$

Base station k sends PMI through downlink control channel_WTo the served user;

wherein,

orth (-) denotes normalizing input parametersIntersection operation, λ ∈ [0, 1]]。

19. The data transmission method according to claim 18, wherein the step E) is specifically:

user based on received PMI_WObtaining optimal precoding information for adjusting a transmitted signal <math> <mrow> <msup> <mi>W</mi> <mo>&prime;</mo> </msup> <mo>=</mo> <msub> <mi>W</mi> <msub> <mi>PMI</mi> <mi>W</mi> </msub> </msub> <mo>;</mo> </mrow> </math>

The above-mentioned

For indexing PMI_WThe code word of (1).

20. A data transmission system for a multiple-input multiple-output, MIMO, system, comprising:

the information interaction unit is used for interacting the user scheduling information of the base stations in the base station set participating in the cooperation in the time-frequency resource block through a network backbone or a backbone network or a special interface between the base stations;

the interference information calculation and transmission unit is used for obtaining interference source user information according to user scheduling information on a time-frequency resource block, obtaining interference information through measured channel information of the interference source user, and transmitting the interference information to a base station to which the interference source user belongs;

the equivalent interference information generating unit is used for receiving interference information sent by other base stations in the cooperative base station set and forming equivalent interference information according to the interference information;

the optimal precoding information generating and sending unit is used for generating information about precoding on a time-frequency resource block by utilizing equivalent interference information and channel information from a user to the user under the base station, and sending the information to the adjusting unit;

and the adjusting unit is used for receiving the information about the precoding to obtain the optimal precoding information and adjusting the sending signal by utilizing the optimal precoding information.

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