CN101997649B - Method and device for processing MU-MIMO (Multiuser Multiple-Input Multiple-Output) based on orthogonal diversity - Google Patents

Abstract

The invention discloses a method for processing multiuser multiple-input multiple-output (MU-MIMO) based on orthogonal diversity, which comprises the steps of: precoding data flows of different users by independent delamination and specific orthogonal diversity, and mapping the data in a space-frequency coded matrix; carrying out multiuser precoding or beam forming (BF) processing on data of different users in the space-frequency coded matrix; and transmitting the processed data subjected to resource mapping outside through a transmitting antenna. The invention also discloses a device for processing MU-MIMO based on orthogonal diversity. By using the method and the device, the processing of multiuser transmitting diversity is realized, the resources of the antenna and carrier waves are fully used, and more users can be multiplexed under the same resource consumption.

Description

MU-MIMO processing method and device based on orthogonal diversity

Technical Field

The present invention relates to a transmit diversity technique in a Long Term Evolution (LTE) system, and in particular, to a method and an apparatus for processing multi-user Multiple Input Multiple Output (MU-MIMO) based on orthogonal diversity.

Background

In the LTE system, the downlink defines that the diversity mode when the transmit antenna is 2 antennas is Space-Frequency coding (SFBC), and the coding matrix is shown as follows:

in the above formula, each row of the matrix corresponds to different transmitting frequencies, and each column of the matrix corresponds to different transmitting antennas; s₁Data, S, representing a mapping to Subcarrier (Subcarrier)1 at a first time instant₂Data, S, representing a second time instant mapping to Subcarrier 2₁ ^*And S₂ ^*Respectively represent S₁And S₂Conjugation of (1).

The Diversity mode when the transmitting antenna is 4 antennas is SFBC + frequency switching Diversity (FSTD), and the coding matrix is shown as the following formula:

in the above formula, each row of the matrix corresponds to different transmitting frequencies, and each column of the matrix corresponds to different transmitting antennas; s₁Representing data, S, mapped to Subcarrier 1 at a first time instant₂Data, S, representing a second time instant mapping to Subcarrier 2₃Data, S, representing the mapping of the third time instant to Subcarrier 3₄Data, S, representing a mapping to Subcarrier 4 at a fourth time₁ ^*、S₂ ^*、S₃ ^*And S₄ ^*Respectively represent S₁、S₂、S₃And S₄Conjugation of (1).

In the existing release of the LTE, 4-antenna transmission does not fully utilize the antenna and carrier resources, and only adopts a single-user transmit diversity scheme, and does not involve multi-user orthogonal diversity multiplexing, thereby limiting the performance of the LTE.

Disclosure of Invention

In view of the above, the main objective of the present invention is to provide a method and an apparatus for MU-MIMO processing based on orthogonal diversity to achieve multi-user transmit diversity processing.

In order to achieve the purpose, the technical scheme of the invention is realized as follows:

the invention provides a multi-user multi-input multi-output MU-MIMO processing method based on orthogonal diversity, which comprises the following steps:

mapping data streams of different users to a space-frequency coding matrix through independent layering and specific orthogonal diversity precoding;

and respectively carrying out multi-user precoding or beam forming BF processing on the data of different users in the space-frequency coding matrix, and carrying out resource mapping on the processed data and then transmitting the processed data to the outside through a transmitting antenna.

The method further comprises the following steps: when the number of transmit antennas is greater than or equal to 8, the specific orthogonal diversity precoding matrix is:

$\left[\begin{array}{cccc}{S}_{11}& S_{23}& -S_{12}^{*}& -S_{24}^{*}\\ S_{12}& S_{24}& S_{11}^{*}& S_{23}^{*}\\ S_{21}& S_{13}& -S_{22}^{*}& {-S}_{14}^{*}\\ S_{22}& S_{14}& S_{21}^{*}& S_{13}^{*}\end{array}\right]$

wherein S is_1iIndicating data transmitted by user 1, S_2iData transmitted by user 2, i is 1,2,3, 4;

the data stream of user 1 is mapped to the matrix of space-frequency coding by layering and diversity pre-coding, and the data stream of user 2 is mapped to the matrix of space-frequency coding by the complementary diversity pre-coding matrix.

The method further comprises the following steps: when the number of transmit antennas is greater than or equal to 8, the specific orthogonal diversity precoding matrix is:

$\left[\begin{array}{cccc}{S}_{11}& S_{12}& S_{23}& S_{24}\\ {-S}_{12}^{*}& S_{11}^{*}& {-S}_{24}^{*}& S_{23}^{*}\\ S_{21}& S_{22}& S_{13}& S_{14}\\ {-S}_{22}^{*}& S_{21}^{*}& {-S}_{14}^{*}& S_{13}^{*}\end{array}\right]$

wherein S is_1iIndicating data transmitted by user 1, S_2iData transmitted by user 2, i is 1,2,3, 4;

the data stream of user 1 is mapped to the matrix of space-frequency coding by layering and diversity pre-coding, and the data stream of user 2 is mapped to the matrix of space-frequency coding by the complementary diversity pre-coding matrix.

The method further comprises the following steps: when the number of transmit antennas is greater than or equal to 8, the specific orthogonal diversity precoding matrix is:

$\left[\begin{array}{cccc}{S}_{11}& S_{12}& -S_{13}^{*}& -S_{14}^{*}\\ {-S}_{12}^{*}& S_{11}^{*}& S_{14}& -S_{13}\\ S_{13}& S_{14}& S_{11}^{*}& S_{12}^{*}\\ {-S}_{14}^{*}& S_{13}^{*}& {-S}_{12}& S_{11}\end{array}\right],$ $\left[\begin{array}{cccc}{S}_{21}& S_{22}& -S_{23}^{*}& -S_{24}^{*}\\ {-S}_{22}^{*}& S_{21}^{*}& S_{24}& {-S}_{23}\\ S_{23}& S_{24}& S_{21}^{*}& S_{22}^{*}\\ -S_{24}^{*}& S_{23}^{*}& {-S}_{22}& S_{21}\end{array}\right]$

wherein S is_1iIndicating data transmitted by user 1, S_2iData transmitted by user 2, i is 1,2,3, 4;

the data stream of user 1 is mapped into the matrix of space-frequency coding by layering and diversity pre-coding, and the data stream of user 2 is mapped into the matrix of space-frequency coding by the same diversity pre-coding matrix as that of user 1.

The multi-user precoding or BF processing specifically includes:

and respectively multiplying the data of different users in the space-frequency coded matrix by different precoding vectors or multiplying by different BF vectors.

The invention also provides an MU-MIMO processing device based on orthogonal diversity, which comprises:

the orthogonal diversity pre-coding module is used for mapping data streams of different users to a space-frequency coding matrix through layering and specific orthogonal diversity pre-coding;

the multi-user pre-coding module is used for respectively carrying out multi-user pre-coding or BF processing on the data of different users in the space-frequency coding matrix;

and the transmitting module is used for transmitting the data processed by the multi-user precoding module to the outside after resource mapping.

When the number of the transmitting antennas is greater than or equal to 8, the orthogonal diversity pre-coding module is further configured to map the data stream of the user 1 to the matrix of the space-frequency code through hierarchical and diversity pre-coding, and map the data stream of the user 2 to the matrix of the space-frequency code through a complementary diversity pre-coding matrix.

When the number of the transmitting antennas is greater than or equal to 8, the orthogonal diversity pre-coding module is further configured to map the data stream of the user 1 into a matrix of the space-frequency code through hierarchical and diversity pre-coding, and map the data stream of the user 2 into the matrix of the space-frequency code through a diversity pre-coding matrix the same as that of the user 1.

The multi-user pre-coding module is further configured to multiply data of different users in the space-frequency coded matrix by different pre-coding vectors or by different BF vectors, respectively.

The invention provides a MU-MIMO processing method and device based on orthogonal diversity, which maps the data flow of different users to the matrix of space-frequency coding through independent layering and specific orthogonal diversity pre-coding; then, the data of different users are respectively processed by multi-user precoding or Beam Forming (BF), and the processed data are transmitted to the outside after resource mapping. The invention fully utilizes the resources of the antenna and the carrier wave through the orthogonal diversity multiplexing of multiple users, and multiplexes more users under the same resource consumption; under the condition of not increasing extra pilot frequency overhead, better performance gain can be obtained; interference between multiple users is eliminated by using precoding and BF techniques, and diversity gain is increased for a single user.

Drawings

FIG. 1 is a flow chart of a method for MU-MIMO processing based on orthogonal diversity according to the present invention;

FIG. 2 is a diagram illustrating MU-MIMO processing based on orthogonal diversity in an embodiment of the present invention;

fig. 3 is a schematic diagram of a composition structure of an MU-MIMO processing apparatus based on orthogonal diversity according to the present invention.

Detailed Description

The technical solution of the present invention is further elaborated below with reference to the drawings and the specific embodiments.

The MU-MIMO processing method based on orthogonal diversity provided by the present invention, as shown in fig. 1, mainly comprises the following steps:

step 101, the base station maps the data streams of different users to the space-frequency coding matrix through independent layering and specific orthogonal diversity pre-coding.

Step 102, respectively performing multi-user precoding or Beamforming (BF) processing on data of different users in the space-frequency coded matrix.

Specifically, the data of different users in the space-frequency coded matrix is multiplied by different precoding vectors or by different BF vectors. And the precoding vector or the BF vector can be obtained by calculation according to interchangeability between an uplink channel and a downlink channel or according to information feedback of the uplink channel to the downlink channel.

And 103, mapping the processed data by resources and then transmitting the data to the outside through a transmitting antenna.

At present, theoretical analysis and simulation verification prove that the diversity output signals are respectively sent into independent beam forming arrays, and 6dB gain can be obtained compared with Alamouti diversity, wherein the coding matrix of the Alamouti diversity is $\left[\begin{array}{cc}{S}_1& S_2\\ -S_2^{*}& S_1^{*}\end{array}\right],$ S1 and S2 are symbols before coding, and the rows correspond to adjacent time instants or adjacent frequencies after Alamouti coding, and the columns represent different transmitting antennas. In addition, the precoding technology can eliminate the interference among multiple users under SFBC, and the diversity performance can be further enhanced by selecting the optimal precoding vector. Therefore, the invention designs the multi-user diversity method of the LTE-Advanced system by combining the pre-coding beam forming and the transmitting diversity.

The corresponding relation in the diversity method with 4 antennas as the transmitting antenna is as follows:

Subcarrier $\left[\begin{array}{cc}{S}_{11}& {-S}_{12}^{*}\\ S_{12}& S_{11}^{*}\end{array}\right]$ user 1

Subcarrier $\left[\begin{array}{cc}{S}_{21}& -S_{22}^{*}\\ S_{22}& S_{21}^{*}\end{array}\right]$ User 2

S_1iFor data transmitted by user 1, S_2iFor the data transmitted by user 2, i is 1,2,3, 4.

The corresponding relation in the diversity method with 8 antennas as the transmitting antennas is as follows:

Subcarrier $\left[\begin{array}{cc}{S}_{11}& -S_{12}^{*}\\ S_{12}& S_{11}^{*}\end{array}\right]$ user 1

Subcarrier $\left[\begin{array}{cc}{S}_{21}& -S_{22}^{*}\\ S_{22}& S_{21}^{*}\end{array}\right]$ User 2

Subcarrier $\left[\begin{array}{cccc}{S}_{11}& S_{23}& -S_{12}^{*}& -S_{24}^{*}\\ S_{12}& S_{24}& S_{11}^{*}& S_{23}^{*}\\ S_{21}& S_{13}& -S_{22}^{*}& {-S}_{14}^{*}\\ S_{22}& S_{14}& S_{21}^{*}& S_{13}^{*}\end{array}\right]$

Under the condition of 8 antennas, 4 users can be multiplexed at most by adopting space-frequency coding of two antennas, and by adopting a coding method in the case of 8 antennas, the pre-coding vector not only can eliminate multi-user interference, but also can enhance the signal energy of the users.

When the transmitting antenna is extended to be an N (N is more than or equal to 8) antenna, the corresponding relation in the corresponding diversity method is as follows:

Subcarrier $\left[\begin{array}{cc}{S}_{11}& -S_{12}^{*}\\ S_{12}& S_{11}^{*}\end{array}\right]$ user 1

Subcarrier $\left[\begin{array}{cc}{S}_{21}& -S_{22}^{*}\\ S_{22}& S_{21}^{*}\end{array}\right]$ User 2

…

Subcarrier $\left[\begin{array}{cc}{S}_{N/\mathrm{2,1}}& -S_{N/\mathrm{2,2}}^{*}\\ S_{N/\mathrm{2,2}}& S_{N/\mathrm{2,1}}^{*}\end{array}\right]$ User N/2

Subcarrier $\left[\begin{array}{cccc}{S}_{11}& S_{23}& -S_{12}^{*}& -S_{24}^{*}\\ S_{12}& S_{24}& S_{11}^{*}& S_{23}^{*}\\ S_{21}& S_{13}& -S_{22}^{*}& {-S}_{14}^{*}\\ S_{22}& S_{14}& S_{21}^{*}& S_{13}^{*}\end{array}\right]$

Wherein S is_niFor the data transmitted by user N, N is 1,2,3, …, N/2, i is 1,2,3, 4. In the case of N antennas, at most N/2 users can be multiplexed by adopting two-antenna space-frequency coding. When the number of users is less than N/2, the coding method of N antennas is adopted, the pre-coding vector not only can eliminate multi-user interference, but also can enhance the signal energy of the users.

The MU-MIMO processing method described above is further elaborated with reference to the specific embodiments based on the schematic diagram of MU-MIMO processing shown in fig. 2.

The first embodiment is as follows: the 4-antenna multi-user 2-antenna diversity encoding matrix is as follows:

Subcarrier $\left[\begin{array}{cc}{S}_{11}& -S_{12}^{*}\\ S_{12}& S_{11}^{*}\end{array}\right]$ user 1

Subcarrier $\left[\begin{array}{cc}{S}_{21}& -S_{22}^{*}\\ S_{22}& S_{21}^{*}\end{array}\right]$ User 2

Two streams of different users (user 1 data stream and user 2 data stream) are respectively divided into two layers, orthogonal diversity precoding is respectively carried out, then different precoding vectors or BF vectors are multiplied for different users, and user data are transmitted through an actual antenna after resource mapping.

On one hand, the Precoding vector or BF vector is used to eliminate interference between multiple users, i.e. interference cancellation is performed by Zero Forcing (ZF), Block Diagonalization (BD), Tomlinson-Harashima Precoding (THP), or by a weighted vector pairing criterion of multiple users; another aspect is that to enhance the diversity gain of each user, a weight vector may be calculated based on a maximum Signal to interference noise Ratio (SINR) criterion of eigenvalue decomposition.

Under the open loop condition, the vector pairing of multiple users is determined by utilizing the interchangeability of channels and calculating a downlink channel correlation matrix through the estimation of an uplink channel correlation matrix; or calculating the Angle of Arrival (AOA) by using the uplink ePlus link to determine the BF vector of each user, and selecting two users with the largest Angle difference (BF vector orthogonal) to be paired. In the closed loop situation, users with two orthogonal Precoding vectors can be selected for pairing by feeding back a Precoding codebook Index (PMI), and channel information (H) can also be fed back_i) And interference elimination among multiple users is realized by using ZF or BD, THP algorithm, and the method can also be usedAnd feeding the autocorrelation matrix of the matrix, and realizing pairing between two users by using a pairing algorithm of the users.

Example two: the 8-antenna multi-user 2-antenna diversity encoding matrix is as follows:

Subcarrier $\left[\begin{array}{cc}{S}_{11}& -S_{12}^{*}\\ S_{12}& S_{11}^{*}\end{array}\right]$ user 1

Subcarrier $\left[\begin{array}{cc}{S}_{21}& -S_{22}^{*}\\ S_{22}& S_{21}^{*}\end{array}\right]$ User 2

Subcarrier $\left[\begin{array}{cc}{S}_{31}& {-S}_{32}^{*}\\ S_{32}& S_{31}^{*}\end{array}\right]$ User 3

Subcarrier $\left[\begin{array}{cc}{S}_{41}& {-S}_{42}^{*}\\ S_{42}& S_{41}^{*}\end{array}\right]$ User 4

When multiplexing 4 users under 8-antenna condition, firstly mapping the streams of the first two users to four layers, then mapping the streams of the second two users to the other four layers, then performing orthogonal diversity precoding respectively, then multiplying different precoding vectors or BF vectors aiming at different users, finally performing resource mapping (mapping to the same time-frequency resource) and sending out through an actual antenna. The calculation method of the pre-coding vector or BF vector is the same as the first embodiment.

It should be noted that, when the channel information is PMI or Rank Index (RI, Rank Index), a Signal-to-leakage-noise Ratio (SLNR) pairing method may be used when there is no optimal orthogonal weighting vector. When fewer users are multiplexed under the 8-antenna condition, the precoding vectors can not only eliminate multi-user interference, but also enhance the signal energy of the users.

Example three: 8-antenna multi-user 4-antenna diversity coding matrix:

Subcarrier $\left[\begin{array}{cccc}{S}_{11}& S_{23}& -S_{12}^{*}& -S_{24}^{*}\\ S_{12}& S_{24}& S_{11}^{*}& S_{23}^{*}\\ S_{21}& S_{13}& -S_{22}^{*}& {-S}_{14}^{*}\\ S_{22}& S_{14}& S_{21}^{*}& S_{13}^{*}\end{array}\right]$

user 1 maps the modulation symbol to the space-frequency coding matrix through layering and diversity pre-coding, user 2 maps the modulation symbol to the space-frequency coding matrix by adopting a complementary diversity pre-coding matrix, then users 1 and 2 respectively carry out multi-user pre-coding or BF processing, and finally the modulation symbol is sent out through an actual antenna after resource mapping. The diversity with 8 antennas can obtain better diversity gain, and the adoption of 8 antennas BF can not only eliminate multi-user interference, but also enhance the signal energy of users. The specific precoding vector or BF vector calculation is as described in embodiment one.

Example four: 8-antenna multi-user 4-antenna diversity coding matrix:

Subcarrier $\left[\begin{array}{cccc}{S}_{11}& S_{12}& S_{23}& S_{24}\\ -S_{12}^{*}& S_{11}^{*}& -S_{24}^{*}& S_{23}^{*}\\ S_{21}& S_{22}& S_{13}& S_{14}\\ -S_{22}^{*}& S_{21}^{*}& {-S}_{14}^{*}& S_{13}^{*}\end{array}\right]$

user 1 maps the modulation symbol to the space-frequency coding matrix through layering and diversity pre-coding, user 2 maps the modulation symbol to the space-frequency coding matrix by adopting a complementary diversity pre-coding matrix, then users 1 and 2 respectively carry out multi-user pre-coding or BF processing, and finally the modulation symbol is sent out through an actual antenna after resource mapping. The difference from example three is the diversity precoding matrix. The specific precoding vector or BF vector calculation is as described in embodiment one.

Example five: 8-antenna multi-user 4-antenna diversity coding matrix:

Subcarrier $\left[\begin{array}{cccc}{S}_{11}& S_{12}& -S_{13}^{*}& -S_{14}^{*}\\ -S_{12}^{*}& S_{11}^{*}& S_{14}& {-S}_{13}\\ S_{13}& S_{14}& S_{11}^{*}& S_{12}^{*}\\ {-S}_{14}^{*}& S_{13}^{*}& -S_{12}& S_{11}\end{array}\right]$ user 1

Subcarrier $\left[\begin{array}{cccc}{S}_{21}& S_{22}& {-S}_{23}^{*}& -S_{24}^{*}\\ -S_{22}^{*}& S_{21}^{*}& S_{24}& {-S}_{23}\\ S_{23}& S_{24}& S_{21}^{*}& S_{22}^{*}\\ -S_{24}^{*}& S_{23}^{*}& -S_{22}& S_{21}\end{array}\right]$ User 2

User 1 maps the modulation symbol to the space-frequency coding matrix through layering and diversity pre-coding, user 2 maps the modulation symbol to the space-frequency coding matrix by using the same diversity pre-coding matrix, then users 1 and 2 respectively carry out multi-user pre-coding or BF processing, and finally the modulation symbol is sent out through an actual antenna after resource mapping (the multi-user occupies the same resources). The difference from the previous example is the diversity precoding matrix. Such a precoding matrix may provide better diversity gain. The specific precoding vector or BF vector calculation is as described in embodiment one.

In order to implement the above-mentioned MU-MIMO processing method based on orthogonal diversity, the present invention further provides a MU-MIMO processing apparatus based on orthogonal diversity, as shown in fig. 3, the apparatus includes: an orthogonal diversity precoding module 10, a multi-user precoding module 20 and a transmitting module 30. An orthogonal diversity pre-coding module 10, configured to map data streams of different users into a space-frequency coded matrix through layered and specific orthogonal diversity pre-coding. A multi-user precoding module 20, configured to perform multi-user precoding or BF processing on data of different users in the space-frequency coded matrix, specifically: and respectively multiplying the data of different users in the space-frequency coded matrix by different precoding vectors or multiplying by different BF vectors. And a transmitting module 30, configured to map the resource of the data processed by the multi-user precoding module 20 and transmit the data to the outside.

The multi-user precoding module 20 may obtain a precoding vector or BF vector according to interchangeability between an uplink channel and a downlink channel, or according to information feedback calculation of the uplink channel to the downlink channel. Under the open-loop condition, the interchangeability of channels can be utilized, and a downlink channel correlation matrix is calculated through the estimation of an uplink channel correlation matrix so as to determine the vector pairing of multiple users; or the AOA is calculated using the uplink to determine the BF vector for each user. Under the closed-loop condition, selecting two users with orthogonal precoding vectors for pairing through a feedback PMI; or by feeding back channel information H_iAnd performing interference elimination among multiple users by using ZF or BD and THP algorithms; or through the autocorrelation matrix of the feedback matrix, and the pairing between the two users is performed by using the pairing algorithm of the users.

When the number of transmit antennas is greater than or equal to 8, the orthogonal diversity precoding module 10 is further configured to map the data stream of user 1 into a space-frequency coded matrix through hierarchical and diversity precoding, and map the data stream of user 2 into a space-frequency coded matrix through a complementary or same diversity precoding matrix.

It should be noted that the SFBC coding scheme employed in the present invention may be modified in many ways, and therefore, the orthogonal space-frequency or space-time coding units may be substituted for the SFBC, SFBC + FSTD coding scheme herein, and all shall be included in the protection scope of the present invention.

The above description is only a preferred embodiment of the present invention, and is not intended to limit the scope of the present invention.

Claims (7)

1. A multi-user multiple-input multiple-output (MU-MIMO) processing method based on orthogonal diversity is characterized by comprising the following steps:

mapping data streams of different users to a space-frequency coding matrix through independent layering and specific orthogonal diversity precoding;

respectively carrying out multi-user precoding or beam forming BF processing on data of different users in the space-frequency coding matrix, and carrying out resource mapping on the processed data and then transmitting the processed data to the outside through a transmitting antenna;

when the number of transmit antennas is greater than or equal to 8, the method further comprises: mapping the data stream of the user 1 into a matrix of space-frequency codes through layering and diversity pre-coding, and mapping the data stream of the user 2 into the matrix of space-frequency codes through a complementary diversity pre-coding matrix; or,

the data stream of user 1 is mapped into the matrix of space-frequency coding by layering and diversity pre-coding, and the data stream of user 2 is mapped into the matrix of space-frequency coding by the same diversity pre-coding matrix as that of user 1.

2. The method of claim 1, wherein when the data stream for user 1 is mapped to the space-frequency coded matrix by hierarchical and diversity pre-coding and the data stream for user 2 is mapped to the space-frequency coded matrix by the complementary diversity pre-coding matrix, the specific orthogonal diversity pre-coding matrix is:

$\left[\begin{array}{cccc}{S}_{11}& S_{23}& {-S}_{12}^{*}& {-S}_{24}^{*}\\ S_{12}& S_{24}& S_{11}^{*}& S_{23}^{*}\\ S_{21}& S_{13}& {-S}_{22}^{*}& {-S}_{14}^{*}\\ S_{22}& S_{14}& S_{21}^{*}& S_{13}^{*}\end{array}\right]$

wherein S is_1iIndicating data transmitted by user 1, S_2iIndicating the data transmitted by user 2, i is 1,2,3, 4.

3. The method of claim 1, wherein when the data stream for user 1 is mapped to the space-frequency coded matrix by hierarchical and diversity pre-coding and the data stream for user 2 is mapped to the space-frequency coded matrix by the complementary diversity pre-coding matrix, the specific orthogonal diversity pre-coding matrix is:

$\left[\begin{array}{cccc}{S}_{11}& S_{12}& S_{23}& S_{24}\\ -S_{12}^{*}& S_{11}^{*}& {-S}_{24}^{*}& S_{23}^{*}\\ S_{21}& S_{22}& S_{13}& S_{14}\\ {-S}_{22}^{*}& S_{21}^{*}& {-S}_{14}^{*}& S_{13}^{*}\end{array}\right]$

wherein S is_1iIndicating data transmitted by user 1, S_2iIndicating the data transmitted by user 2, i is 1,2,3, 4.

4. The method of claim 1, wherein when the data stream for user 1 is mapped to the space-frequency coded matrix by hierarchical and diversity pre-coding and the data stream for user 2 is mapped to the space-frequency coded matrix by the same diversity pre-coding matrix as user 1, the specific orthogonal diversity pre-coding matrix is:

$\left[\begin{array}{cccc}{S}_{11}& S_{12}& {-S}_{13}^{*}& {-S}_{14}^{*}\\ {-S}_{12}^{*}& S_{11}^{*}& S_{14}& {-S}_{13}\\ S_{13}& S_{14}& S_{11}^{*}& S_{12}^{*}\\ {-S}_{14}^{*}& S_{13}^{*}& {-S}_{12}& S_{11}\end{array}\right],\left[\begin{array}{cccc}{S}_{21}& S_{22}& {-S}_{23}^{*}& {-S}_{24}^{*}\\ {-S}_{22}^{*}& S_{21}^{*}& S_{24}& {-S}_{23}\\ S_{23}& S_{24}& S_{21}^{*}& S_{22}^{*}\\ {-S}_{24}^{*}& S_{23}^{*}& {-S}_{22}& S_{21}\end{array}\right]$

wherein S is_1iIndicating data transmitted by user 1, S_2iIndicating the data transmitted by user 2, i is 1,2,3, 4.

5. The method for MU-MIMO processing based on orthogonal diversity according to any of claims 1 to 4, wherein the multi-user precoding or BF processing is specifically:

and respectively multiplying the data of different users in the space-frequency coded matrix by different precoding vectors or multiplying by different BF vectors.

6. A multi-user multiple-input multiple-output (MU-MIMO) processing apparatus based on orthogonal diversity, the apparatus comprising:

the orthogonal diversity pre-coding module is used for mapping data streams of different users to a space-frequency coding matrix through layering and specific orthogonal diversity pre-coding;

the multi-user pre-coding module is used for respectively carrying out multi-user pre-coding or beam forming BF processing on the data of different users in the space-frequency coding matrix;

the transmitting module is used for transmitting the data processed by the multi-user precoding module to the outside after resource mapping;

when the number of transmit antennas is greater than or equal to 8, the orthogonal diversity precoding module is further configured to,

mapping the data stream of the user 1 into a matrix of space-frequency codes through layering and diversity pre-coding, and mapping the data stream of the user 2 into the matrix of space-frequency codes through a complementary diversity pre-coding matrix; or,

the data stream of user 1 is mapped into the matrix of space-frequency coding by layering and diversity pre-coding, and the data stream of user 2 is mapped into the matrix of space-frequency coding by the same diversity pre-coding matrix as that of user 1.

7. The apparatus of claim 6, wherein the multi-user precoding module is further configured to multiply data of different users in the space-frequency encoded matrix by different precoding vectors or by different BF vectors, respectively.