WO2014107888A1

WO2014107888A1 - Transmission method and base station for downlink multiple-input multiple-output

Info

Publication number: WO2014107888A1
Application number: PCT/CN2013/070381
Authority: WO
Inventors: 杨敬; 马霓; 蒋培刚
Original assignee: 华为技术有限公司
Priority date: 2013-01-11
Filing date: 2013-01-11
Publication date: 2014-07-17
Also published as: CN104185956B; CN104185956A

Abstract

Disclosed is a transmission method for downlink Multiple-Input Multiple-Output (MIMO), the method comprising: the precoding matrix indicators (PMI) transmitted by at least two user equipment are received and it is determined that the at least two user equipment is in the paired state according to the multi-user MIMO (MU-MIMO) pairing criteria; according to the PMI transmitted by the first user equipment, the beamforming and pairing power adjustment are performed to the transmission data on the Physical Downlink Shared Channel (PDSCH) distributed to the first user equipment in the first mode of the Long Term Evolution (LTE) transmission modes; the beamforming weights adjustment is performed to the second user equipment in the second mode so that the precoding matrix weights of the second user equipment are orthogonal with those of the first user equipment, and the power adjustment is performed to the second user equipment to satisfy the total power constraint of the paired first user equipment and second user equipment. The problem of pairing the user equipment in different MIMO modes could be solved with the method provided by the embodiments of the invention.

Description

Downlink multiple input multiple output transmission method and base station

Technical field

The present invention relates to the field of communications, and in particular, to a downlink multiple input multiple output transmission method and apparatus. Background technique

Multi-User Multiple Input-Multiple-Output (MU-MIMO) is a spatial freedom that utilizes multi-user channels to multiplex multiple downlink user data into the same time-frequency domain resource. Division Division Multiple Access (SDMA) gain. For downlink MU-MIMO, it is difficult to implement joint detection by each user, so it is multiplexed at the base.

In order to improve network performance, the implementation process of MU-MIMO related technology is introduced in each protocol version in the Long Term Evolution Frequency Division Duplexing (LTE FDD) system. In LTE protocol version 8, MU-MIMO is implemented by Transmission Mode (TM5) and Downlink Control Information (DCI) 1C signaling format. Wherein, the TM5 mode is used in a cell-specific reference signals (CRS) and a pre-coded mode for beamforming weights on the user, and the DCI 1D carries 1 bit of power offset information for Power allocation at the time of pairing.

LTE protocol version 10 based on version 8, through the newly introduced transmission mode (Transmission

Mode, TM9) MIMO mode and DCI Format 2C format for MU-MIMO characteristics support. In TM9 mode, the user's weight and power information is carried by Demodulation Reference Signal (DMRS); therefore, in TM9 mode, multi-user multiple input multiple output (MU-MIMO) and single user multiple input The output (SU-MIMO) is transparent to the UE and can be dynamically switched between multi-user multiple input multiple output and single user multiple input multiple output.

In the Release 8 protocol, the user equipment can only use the pre-coding matrix indicator (PMI) of the existing orthogonal RANK1 for multi-user (MU) pairing, but the PMI of RANK1 is orthogonal to each other. The ratio is lower. Under the R10 protocol, the DMRS scrambling code is not orthogonal after the number of pairing layers exceeds 2, which affects the channel estimation accuracy of the DMRS channel. Therefore, how to implement the paired transmission of the user equipment in the two modes of TM9 and TM5 in the case of being transparent to the user equipment is a technical problem to be solved by the present invention. Summary of the invention

A downlink MIMO transmission method and apparatus provided by the embodiments of the present invention are provided to solve the problem of pairing user equipments in different MIMO modes.

In a first aspect, an embodiment of the present invention provides a downlink MIMO transmission method, where the method includes:

Receiving precoding matrix indication information sent by at least two user equipments, and determining, according to the multi-user multiple input multiple output pairing criterion, that the at least two user equipments are in a pairing state;

Precoding matrix indication information sent by the first user equipment of the at least two user equipments

The PMI, the beamforming and the pairing power adjustment of the transmission data on the physical downlink shared channel PDSCH allocated by the first user equipment, where the first user equipment is in the first mode in the long term evolution LTE transmission mode ;

Performing beamforming weight adjustment on the second user equipment in the second mode in the LTE transmission mode of the at least two user equipments, so that the second user equipment and the first user equipment The weights of the precoding matrix are orthogonal, and the second user equipment is power adjusted to meet the total power constraint of the first user equipment and the second user equipment after pairing.

Based on the first aspect, in a first possible implementation manner, the first mode is a transmission mode 5 TM5 mode of the LTE system, and the second mode is a single layer transmission mode of the LTE system. 9 TM9 RANKL

Based on the first aspect, in a second possible implementation manner, the first mode is a transmission mode 5TM5 mode of the LTE system, and the second mode is a dual layer transmission mode 9 TM9 RANK2 of the LTE system.

Based on the first aspect, in a third possible implementation, the second user equipment performs beamforming weight adjustment to implement precoding of the second user equipment and the first user equipment. The matrix indicates information orthogonalization, and performs power adjustment on the second user equipment to meet the total power constraint of the first user equipment and the second user equipment after the pairing, and further includes: The power of the first user equipment is set to 0 at a corresponding frequency domain resource unit location of the port of the pilot signal.

In a first possible implementation manner, the fourth possible implementation manner is further provided, where the weight adjustment is performed on the second user equipment to implement the second user equipment and the In the orthogonalization of the precoding matrix indication information of the first user equipment, the weight adjustment method of the second user equipment is specifically: where w. . a precoding weight matrix corresponding to the PMI index fed back by the first user equipment in the TM5 mode, _W1 . a precoding weight matrix corresponding to the PMI index fed back by the second user equipment in the TM9 mode. For the corrected precoding weight matrix of the second user equipment, it is a conjugate transposed matrix of w _∞ .

In a first possible implementation manner, the fifth possible implementation manner is further provided, where the second user equipment is power adjusted to meet the first use after the pairing. The total power constraint of the user equipment and the second user equipment is specifically: the MU power adjusted weight matrix of the first user equipment is the MU power adjusted weight matrix of the second user equipment:

Where w. . a precoding weight matrix corresponding to the PMI index fed back by the first user equipment in the TM5 mode, _W1 . a precoding weight matrix corresponding to the PMI index fed back by the second user equipment in the TM9 mode. For the corrected precoding weight matrix of the second user equipment, the conjugate transposed matrix of w _∞ , |itg| represents the pair. Vector finds 2-norm.

Based on the second possible implementation of the first aspect, a sixth possible implementation manner is further provided, where the weight adjustment is performed on the second user equipment, to implement the second user equipment and the In the orthogonalization of the precoding matrix indication information of a user equipment, the weight adjustment method of the second user equipment is specifically:

'10 = ^ιο - ^οο^ιο^οο = W - W _m W _n W ₀₀ - W _w W _n W _w

Where w. . a precoding weight matrix corresponding to the PMI index fed back by the first user equipment in the TM5 mode, and a precoding matrix weight corresponding to the RANK2 PMI index fed back by the second user equipment in the TM9 mode. And the precoding weight matrix of the modified second user equipment, which is a conjugate transposed matrix of W _,, is ^. Conjugate transposed matrix.

According to the second possible implementation manner of the first aspect, a seventh possible implementation manner is further provided, where the second user equipment is power-adjusted to meet the first user equipment and the The total power constraint of the second user equipment is specifically: the MM power adjusted weight matrix of the first user equipment is: 2 the MU power adjusted weight matrix of the second user equipment is:

The woo is a precoding weight matrix corresponding to the PMI index fed back by the first user equipment in the Γ mode, and ^w “the precoding matrix weight corresponding to the RANK2 PMI index fed back by the second user equipment in the TM9 mode. The value, . and the corrected pre-encoding weight matrix of the second user equipment, |.|| denotes a pair. The vector finds a 2-norm, and I JI denotes a 2-norm of the vector.

In a second aspect, an embodiment of the present invention provides a base station, where the base station includes:

a determining module, receiving precoding matrix indication information sent by at least two user equipments, and determining, according to the MU-MIMO pairing criterion, that the at least two user equipments are in a pairing state;

a first adjustment module, configured to allocate, according to the precoding matrix indication information PMI sent by the first user equipment of the at least two user equipments, the first user equipment to the transmission data on the physical downlink shared channel PDSCH of the first user equipment a beamforming weight and a pairing power adjustment, where the first user equipment is in a first mode in a long term evolution LTE transmission mode;

The second adjustment module performs beamforming weight adjustment on the second user equipment in the second mode in the LTE transmission mode of the at least two user equipments, so that the second user equipment and the first user The precoding matrix of the device indicates orthogonal information, and performs power adjustment on the second user equipment to meet the total power constraint of the first user equipment and the second user equipment after pairing.

Based on the second aspect, in a first possible implementation manner, the first mode is an LTE system transmission mode 5TM5 mode, and the second mode is an LTE system single layer transmission mode. 9 TM9 RANKL

Based on the second aspect, the first mode is an LTE system transmission mode 5 TM5 mode, and the second mode is an LTE system dual layer transmission mode 9 TM9 RANK2.

Based on the first aspect, in a third possible implementation, the third adjustment module is further configured to perform weight adjustment on the second user equipment by the second adjustment module, to implement the second user. The device is orthogonalized with the precoding matrix indication information of the first user equipment, and the second After the user equipment performs power adjustment to meet the total power constraint of the first user equipment and the second user equipment after the pairing,

The power of the first user equipment is set to 0 at a corresponding frequency domain resource unit location of the port of the demodulation pilot signal.

In a first possible implementation manner of the second aspect, a fourth possible implementation manner is further provided, where the second adjustment module adjusts the weight of the second user equipment by:

3⁄4 = ^ιο - ^ο ιο^οο

Where w. . a precoding weight matrix corresponding to the PMI index fed back by the first user equipment in the TM5 mode, _W1 . a precoding weight matrix corresponding to the PMI index fed back by the second user equipment in the TM9 mode. For the corrected precoding weight matrix of the second user equipment, it is a conjugate transposed matrix of w _∞ .

In a first possible implementation manner of the second aspect, a fifth possible implementation manner is further provided, where the second adjustment module performs power adjustment on the second user equipment to meet the pairing manner. The total power constraint of the first user equipment and the second user equipment: the MU power adjusted weight matrix of the first user equipment is: . = ^w. . The weighted matrix of the second user equipment after the MU power adjustment is: . =

Where w. . a precoding weight matrix corresponding to the PMI index fed back by the first user equipment in the TM5 mode, _W1 . a precoding weight matrix corresponding to the PMI index fed back by the second user equipment in the TM9 mode. For the corrected precoding weight matrix of the second user equipment, the conjugate transposed matrix of w _∞ , μ. | Indicates right. Vector finds 2-norm. .

According to the second possible implementation manner of the second aspect, a sixth possible implementation manner is further provided, where the second adjustment module performs weight adjustment on the second user equipment to implement the foregoing Orthogonalizing the precoding matrix indication information of the second user equipment and the first user equipment The weight adjustment of the second user equipment:

10 = - w3⁄4 ₀ w ₀₀ , w _u = w _u - w^w _u w ₀₀ - w _u .

The woo is a precoding weight matrix corresponding to the PMI index fed back by the first user equipment in the Γ mode, and ^w “the precoding matrix weight corresponding to the RANK2 PMI index fed back by the second user equipment in the TM9 mode. The value, and the matrix of the precoding weights of the modified second user equipment, the conjugate transposed matrix of w _∞ , is the conjugate transposed matrix of ^.

According to the second possible implementation manner of the second aspect, a seventh possible implementation manner is further provided, where the second adjustment module performs power adjustment on the second user equipment to meet the pairing manner. The total power constraint of the first user equipment and the second user equipment: the MU power adjusted weight matrix of the first user equipment is: 2 ^ ⁰⁰ ; after the MU power adjustment of the second user equipment The weight matrix is: ² IK

The woo is a precoding weight matrix corresponding to the PMI index fed back by the first user equipment in the Γ mode, and ^ is a precoding matrix weight corresponding to the RANK2 PMI index fed back by the second user equipment in the TM9 mode. , . And a precoding weight matrix for the modified second user equipment, . | means right. The vector finds the 2-norm, | | represents the 2-norm of the vector.

In a third aspect, an embodiment of the present invention provides a base station, where the base station includes a receiver and a processor;

The receiver is configured to receive precoding matrix indication information sent by at least two user equipments;

The processor is configured to determine, according to the multi-user multiple input multiple output pairing criterion, that the at least two user equipments are in a pairing state, and send according to the first user equipment of the at least two user equipments. Precoding matrix indicating information beamforming and pairing power adjustment of transmission data on a PDSCH allocated by a first user equipment in a first mode in an LTE transmission mode, and being in the at least two user equipments The second user equipment in the second mode of the LTE transmission mode performs beamforming weight adjustment, so that the second user equipment is orthogonal to the precoding matrix weight of the first user equipment, and the second The user equipment performs power adjustment to meet the total power constraint of the first user equipment and the second user equipment after pairing.

The downlink MIMO transmission method provided by the embodiment of the present invention determines that the first user equipment is in a pairing state by using precoding matrix indication information sent by the first user equipment in the first MU mode, and then the first user equipment performs corresponding data. Beamforming and pairing power adjustment; determining that the second user equipment is in a pairing state and beamforming the second user equipment according to the demodulation pilot signal DMRS sent by the second user equipment in the second MU mode a weight adjustment and a power adjustment to orthogonalize the precoding matrix weights of the second user equipment and the first user equipment, and satisfy the total of the first user equipment and the second user equipment after pairing Power constraint, so as to achieve the pairing problem of user equipment in different MIMO modes. DRAWINGS

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the embodiments or the description of the prior art will be briefly described below. Obviously, the drawings in the following description are merely the present invention. Some of the embodiments can be obtained by those skilled in the art from the drawings without any inventive labor.

1 is a flowchart of an embodiment of a downlink MIMO transmission method according to an embodiment of the present invention; FIG. 2 is a structural diagram of a base station according to an embodiment of the present invention;

FIG. 3 is a structural diagram of another embodiment of a base station according to an embodiment of the present invention. detailed description

The technical solution of the present invention will be further described in detail below through the accompanying drawings and embodiments. The TM5 mode introduced in the LTE R8 protocol can support the MU-MIMO feature. It performs 7-carrier MU-MIMO weight based on CRS and PMI. Therefore, in order to obtain better MU-MIMO gain, orthogonal codebook-based pairing is suitable. The way to deal with it. In TM5 mode, the main process of MU-MIMO pairing is as follows:

First, the base station determines whether the UE needs to be paired based on the existing pairing criterion. The pairing criterion may be, for example, a base station, and receives a RANK1 PMI fed back by the UE in the TM5 mode, and then according to whether the codebook is orthogonal and the estimated pairing is performed. The subsequent MU-MIMO spectral efficiency comprehensively determines whether the UE needs to perform MU-MIMO pairing, and the pairing criterion is an existing rule, and is not explained much.

If the base station decides that the UE needs to perform MU-MIMO pairing, the base station sets the power offset value in the DCI 1D to 0, and the data channel power of the UE is halved;

If the base station decides that the UE does not need to perform MU-MIMO pairing, the DCI 1D power is configured to be 1, and the data channel power of the UE is unchanged;

Regardless of whether the base station decides whether the UE needs to perform MU-MIMO pairing, the base station indicates the PMI used by the current UE's data channel to the UE in the DCI ID.

The disadvantage is that this mode can only use the existing orthogonal RANK1 PMI for MU pairing; however, the RANK1 PMI has a low ratio of two orthogonals, only 25%, so the pairing is greatly limited by the codebook.

In the R10 protocol, the TM9 mode introduced by the R10 protocol can also support the MU-MIMO feature. According to the TM9 MIMO mode feature, it is based on DMRS for MU-MIMO weight and user data power. According to this characteristic, when the MU-MIMO pairing is performed in the TM9 mode, the base station can be constrained by whether the PMI matrix or the matrix is orthogonal, and the base station can obtain a more suitable transmission weight by an appropriate beamforming weight algorithm scheme.

Then, in view of this, an embodiment of the present invention provides a downlink MIMO transmission method, and FIG. 1 is a flowchart of a downlink MIMO transmission method provided by this embodiment, where the method may include:

S101. Receive precoding matrix indication information sent by at least two user equipments, and according to The MU-MIMO pairing criterion determines that the at least two user equipments are in a pairing state; at least two of the user equipments may be in different modes, for example, the first user equipment is in the first mode, and the second user equipment is in the second mode.

In particular, the first mode may be the TM5 MIMO mode in the LTE system R8 protocol, or the TM4, TM6 mode. These transmission modes are based on CRS and PMI for MU-MIMO weight bearing mode.

The base station receives the RANK1 PMI fed back by the UE in the TM5 mode, and then comprehensively determines whether the UE needs to perform MU-MIMO pairing according to whether the codebook is orthogonal and the estimated paired MU-MIMO spectrum efficiency. The MU-MIMO pairing criterion may refer to the existing MU-MIMO pairing criterion. The rule, for example, may be a base station, and receives the RANK1 PMI fed back by the UE in the TM5 mode, and then comprehensively determines whether the UE needs to perform MU-MIMO pairing according to whether the codebook is orthogonal and the estimated paired MU-MIMO spectrum efficiency. If the base station decides that the UE performs MU-MIMO pairing, the power offset value in the DCI 1D is set to 0, and the UE data channel power is halved; if the base station decides that the UE does not perform MU-MIMO pairing, the power in the DCI 1D is configured as 1 . The UE data channel power is unchanged. In this embodiment, since the user equipments in the two modes can be paired, the default is to determine that the first user equipment UE0 in the first mode performs MU-MIMO pairing.

The second mode may be the TM9 RANK1/RANK2 mode in the R10 protocol. The second mode may be a mode of carrying MU-MIMO weights and user data power based on DMRS. When the MU-MIMO pairing is performed in the TM9 mode, the base station can obtain a more suitable transmission weight by an appropriate beamforming weight algorithm scheme without being constrained by whether the PMI matrix or the matrix is orthogonal. Also in order to enable the user equipments in the two modes to be paired, it is determined by default that the second user equipment UE1 in the second mode also needs to perform MU-MIMO pairing.

S102. The physical downlink shared channel allocated to the first user equipment in the first mode in the LTE transmission mode according to the precoding matrix indication information sent by the first user equipment in the at least two user equipments. Transmission data on PDSCH) Beamforming and pairing power adjustment;

Specifically, the base station sets the power offset value to 0 in DCI 1D to achieve the purpose of power halving and data beam shaping weight adjustment.

S103, performing weight adjustment on the second user equipment in the second mode of the at least two user equipments, to implement orthogonality of weights of the precoding matrix of the second user equipment and the first user equipment, and The second user equipment performs power adjustment to meet the total power constraint of the first user equipment and the second user equipment after pairing.

In this step, the base station may adjust the weight of the second user equipment UE1 to implement orthogonalization of the precoding matrix indication information of the second user equipment and the first user equipment to avoid interference. At the same time, the data is adjusted in power so that the base station's transmit power is not greater than the total power of the base station.

Certainly, after S103, the UEO data power may be set to 0 in the MFRS port corresponding to the resource element (Resource Element, RE) to achieve mutual interference in the frequency domain, and the uplink physical channel is used for uplink transmission. The smallest resource unit is called a resource element.

With the downlink MIMO transmission method provided by the embodiment of the present invention, paired transmission of MU-MIMO and orthogonalization of pilots can be implemented under the premise of being transparent to the UE.

Optionally, the first mode is a TM5 mode, and the second mode is a TM9 RANK1 mode. In the scenario where the first mode is the TM5 mode and the second mode is the TM9 RANK1 mode, the weight of the second user equipment can be adjusted as follows: where w. . a precoding weight matrix corresponding to the PMI index fed back by the first user equipment in the TM5 mode, and w _1Q is a precoding weight matrix corresponding to the PMI index fed back by the second user equipment in the TM9 mode. The corrected precoding weight matrix of the first user equipment is a conjugate transposed matrix of w ₀₀ .

In the scenario where the first mode is the TM5 mode and the second mode is the TM9 RANK1 mode, the second user equipment may be power-adjusted to meet the first user setting after the pairing. And a total power constraint of the second user equipment: the MU power adjusted weight matrix of the first user equipment is: = ^w ₍ The MU power adjusted weight matrix of the second user equipment is: .

Where w. . a precoding weight matrix corresponding to the PMI index fed back by the first user equipment in the TM5 mode, _W1 . a precoding weight matrix corresponding to the PMI index fed back by the second user equipment in the TM9 mode. For the corrected precoding weight matrix of the second user equipment, the conjugate transposed matrix of w _∞ , 1^. 1 means right. The vector finds the 2-norm (also called the Frobenius norm) to reach ^. The purpose of normalization.

In another embodiment, the first mode may be a TM5 mode and the second mode may be a TM9 RANK2 mode.

In the scenario where the first mode is the TM5 mode and the second mode is the dual-layer transmission mode TM9 RANK2, the second user equipment may be weighted to implement the second user equipment and the first user equipment. Precoding matrix indicates information orthogonalization: where woo is a precoding weight matrix corresponding to a PMI index fed back by the first user equipment in the Γ mode, and ^w "is a second user equipment feedback in the TM9 mode The precoding matrix weight corresponding to the RANK2PMI index, and the precoding weight matrix of the modified second user equipment, the conjugate transposed matrix of w., the conjugate transposed matrix of 3⁄4.

In the scenario where the first mode is the TM5 mode and the second mode is the dual-layer transmission mode TM9 RANK2, the second user equipment may be power-adjusted in the following manner to meet the paired user equipment and the second user. The total power constraint of the device is specifically as follows: The MM power adjusted weight matrix of the first user equipment is: = ^w _m The MU power adjusted weight matrix of the second user equipment is: =^, i _n = - i where woo is the precoding weight matrix corresponding to the PMI index fed back by the first user equipment in the Γ mode, ^ is a precoding matrix weight corresponding to the RANK2 PMI index fed back by the second user equipment in the TM9 mode. And the precoding weight of the modified second user equipment

Norm pair normalization.

Correspondingly, the embodiment of the present invention further provides a base station, and the structure thereof is as shown in FIG. 2, the base station may be an enodeB, and the base station may include:

The determining module 201 is configured to receive precoding matrix indication information sent by at least two user equipments in different modes, and determine, according to the MU-MIMO pairing criterion, that the at least two first user equipments are in a pairing state;

The first adjustment module 202, according to the precoding matrix indication information PMI sent by the first user equipment of the at least two user equipments, performs the transmission on the physical downlink shared channel PDSCH allocated by the first user equipment to the first user equipment. a beamforming weight and a pairing power adjustment of the data, where the first user equipment is in a first mode in a long term evolution LTE transmission mode;

The second adjustment module 203 performs beam shaping weight adjustment on the second user equipment in the second mode in the LTE transmission mode of the at least two user equipments, so that the second user equipment and the first The precoding matrix indication information of the user equipment is orthogonal, and power adjustment is performed on the second user equipment to meet the total power constraint of the first user equipment and the second user equipment after pairing.

In a preferred embodiment, the base station may further include the third adjustment module 204 performing weight adjustment on the second user equipment to implement the second user equipment and the first user. The precoding matrix of the device indicates information orthogonalization, and performs power adjustment on the second user equipment to meet the total power constraint of the first user equipment and the second user equipment after pairing, and further Includes:

In an optional implementation manner, the first mode is a TM5 mode of a Long Term Evolution (LTE) system, and the second mode is a TM9 RANK1 mode of an LTE system.

The second adjustment module 203 performs weight adjustment on the second user equipment to implement orthogonalization of precoding matrix indication information of the second user equipment and the first user equipment, where the second user The weight adjustment method of the device is specifically as follows: where, w. . a precoding weight matrix corresponding to the PMI index fed back by the first user equipment in the TM5 mode, and w1O is a precoding weight matrix corresponding to the PMI index fed back by the second user equipment in the TM9 mode, which is a modified The precoding weight matrix of the second user equipment is a conjugate transposed matrix of w _∞ .

The second adjustment module 203 performs power adjustment on the second user equipment to meet the total power constraint of the first user equipment and the second user equipment after the pairing is specifically as follows: The MU power adjusted weight matrix is:

The MU power adjusted weight matrix of the second user equipment is: ^{1Q 2} 1 . I. In another optional implementation manner, the first mode is a TM5 mode of an LTE system, and the second mode is a TM9 RANK2 mode of an LTE system.

The second adjustment module 203 performs weight adjustment on the second user equipment to implement orthogonalization of precoding matrix indication information of the second user equipment and the first user equipment, where the second user The weight adjustment method of the device is specifically as follows: The wOO is a precoding weight matrix corresponding to the PMI index fed back by the first user equipment in the TM5 mode, and ^ is a precoding matrix weight corresponding to the RANK2PMI index fed back by the second user equipment in the TM9 mode, . And a matrix of precoding weights for the modified second user equipment.

The power adjustment is performed on the second user equipment to meet the total power constraint of the first user equipment and the second user equipment after the pairing is specifically:

The MU power adjusted weight matrix of the second user equipment is: ² ll ^Wi . Ll ,

^{11 _} .

Further, the implementation manners and interaction processes of the modules of the base station in this embodiment may refer to related descriptions in the method embodiments.

Correspondingly, please refer to FIG. 3 , which is a schematic structural diagram of a base station according to an embodiment of the present invention. As shown, the base station can include a receiver 31 and a processor 34. Of course, the base station may also include a common component such as an antenna, a baseband processing component, a medium-frequency processing component, and an input/output device. The embodiment of the present invention is not limited herein.

The receiver 31 is configured to receive precoding matrix indication information sent by at least two user equipments;

The processor 34 is configured to determine, according to the multi-user multiple input multiple output pairing criterion, that the at least two user equipments are in a pairing state, according to the precoding matrix indication information sent by the first user equipment of the at least two user equipments. Beamforming and pairing power adjustment of transmission data on the downlink physical shared channel PDSCH obtained by the first user equipment in the first mode in the LTE transmission mode, and in the LTE transmission mode of the at least two user equipments The second user equipment of the second mode performs beamforming weight adjustment, so that the second user equipment and the first The precoding matrix weights of the user equipment are orthogonal, and the second user equipment is power adjusted to meet the total power constraint of the first user equipment and the second user equipment after pairing.

It should be noted that the base station shown in FIG. 3 is similar to the foregoing embodiment in any of the methods provided in the foregoing method embodiments, and details are not described herein again.

Those skilled in the art should further appreciate that the elements and algorithm steps of the various examples described in connection with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of both, for clarity. Interchangeability of hardware and software In the above description, the composition and steps of the examples have been generally described in terms of functions. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the solution. The skilled person can use different methods for implementing the described functions for each particular application, but such implementation should not be considered to be beyond the scope of the present invention.

The steps of a method or algorithm described in connection with the embodiments disclosed herein can be implemented in hardware, a software module executed by a processor, or a combination of both. The software module can be placed in random access memory (RAM), memory, read only memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, registers, hard disk, removable disk, CD-ROM, or technical field. Any other form of storage medium known.

The above described embodiments of the present invention are further described in detail, and the embodiments of the present invention are intended to be illustrative only. The scope of the protection, any modifications, equivalents, improvements, etc., made within the spirit and scope of the invention are intended to be included within the scope of the invention.

Claims

claims

1. A downlink multiple-input multiple-output MIMO transmission method, characterized in that the method includes:

Receive precoding matrix indication information sent by at least two user equipments, and determine that the at least two user equipments are in a paired state according to the multi-user multiple-input multiple-output pairing criteria;

perform beamforming and pairing power adjustment on the transmission data on the physical downlink shared channel PDSCH allocated to the first user equipment according to the precoding matrix indication information PMI sent by the first user equipment among the at least two user equipments, Wherein, the first user equipment is in a first mode in the Long Term Evolution LTE transmission mode;

Beamforming weight adjustment is performed on the second user equipment in the second mode of the LTE transmission mode among the at least two user equipments, so that the precoding matrix of the second user equipment and the first user equipment The weights of are orthogonal, and the power of the second user equipment is adjusted to satisfy the total power constraint of the first user equipment and the second user equipment after pairing.

2. The downlink MIMO transmission method according to claim 1, wherein the first mode is the transmission mode 5 TM5 of the LTE system, and the second mode is the single-layer transmission mode 9 TM9 RANKL of the LTE system.

3. The downlink MIMO transmission method according to claim 1, wherein the first mode is the transmission mode 5 TM5 mode of the LTE system, and the second mode is the double-layer transmission mode 9 TM9 RANK2 of the LTE system.

4. The downlink MIMO transmission method according to claim 1, wherein the beamforming weight adjustment is performed on the second user equipment to realize the communication between the second user equipment and the first user equipment. After orthogonalizing the precoding matrix indication information and performing power adjustment on the second user equipment to meet the total power constraints of the first user equipment and the second user equipment after pairing, it also includes:

At the corresponding frequency domain resource unit position of the port of the demodulated pilot signal, the first user is configured The power of the device is set to 0.

5. The downlink MIMO transmission method according to claim 2, wherein the beamforming weight of the second user equipment is adjusted in the following manner:

^10 = ^10 - ^0^10^00

Among them, w. . is the precoding weight matrix corresponding to the PMI index fed back by the first user equipment in the TM5 mode, _Wl . is the precoding weight matrix corresponding to the PMI index fed back by the second user equipment in the TM9 mode, . is the modified precoding weight matrix of the second user equipment, and is the conjugate transposed matrix of w _∞ .

6. The downlink MIMO transmission method according to claim 2, wherein the power adjustment is performed on the second user equipment to meet the total power consumption of the first user equipment and the second user equipment after pairing. The power constraints include: The weight matrix of the first user equipment after multi-user power adjustment is: . . = _w . . ; The weight matrix of the second user equipment after multi-user power adjustment is: . = . Among them, w. . is the precoding weight matrix corresponding to the PMI index fed back by the first user equipment in the TM5 mode, _Wl . is the precoding weight matrix corresponding to the PMI index fed back by the second user equipment in the TM9 mode, is the modified precoding weight matrix of the second user equipment, is the conjugate transpose matrix of w _∞ , μ. | means right. Find the 2-norm of a vector.

7. The downlink MIMO transmission method according to claim 3, wherein the beamforming weight adjustment is performed on the second user equipment to realize the communication between the second user equipment and the first user equipment. In the orthogonalization of the precoding matrix indication information, the weight adjustment method of the second user equipment includes:

^io = ^w w - ^ο ιο^οο, ^ί = ^ί - ^ο ιο^οο - ^1 11^10

Among them, w. . is the preset corresponding to the PMI index fed back by the first user equipment in the TM5 mode. Coding weight matrices, , ^ are the precoding matrix weights corresponding to the RANK2 PMI index fed back by the second user equipment in the TM9 mode, . and is the modified precoding weight matrix of the second user equipment, is the conjugate transposed matrix of w _∞ , ^ ^ is ^. The conjugate transpose matrix of .

8. The downlink MIMO transmission method according to claim 2, wherein the power adjustment is performed on the second user equipment to meet the total power consumption of the first user equipment and the second user equipment after pairing. The power constraints include: the weight matrix of the first user equipment after multi-user power adjustment is: 2 ^W °°; the weight matrix of the second user equipment after multi-user power adjustment is: = ,

Wherein, woo is the precoding weight matrix corresponding to the PMI index fed back by the first user equipment in the Γ mode, and , ^ are the precoding matrix weights corresponding to the RANK2 PMI index fed back by the second user equipment in the TM9 mode. , . and is the modified precoding weight matrix of the second user equipment, and I J represents the pair of . Find the 2-norm of a vector, which means finding the 2-norm of the vector.

9. A base station, characterized by including:

The determination module receives the precoding matrix indication information sent by at least two user equipments, and determines the

The MU-MIMO pairing criterion determines that the at least two user equipments are in a paired state;

A first adjustment module, based on the precoding matrix indication information PMI sent by the first user equipment among the at least two user equipments, the beamforming sum of the transmission data on the physical downlink shared channel PDSCH allocated to the first user equipment. Pairing power adjustment, wherein the first user equipment is in the first mode in the long-term evolution LTE transmission mode;

The second adjustment module performs beamforming weight adjustment on the second user equipment in the second mode of the LTE transmission mode among the at least two user equipments, so that the second user equipment is consistent with the second user equipment. The precoding matrix weights of the first user equipment are orthogonal, and the power of the second user equipment is adjusted to meet the total power constraints of the first user equipment and the second user equipment after pairing.

10. The base station of claim 9, wherein the first mode is LTE system transmission mode 5 TM5, and the second mode is LTE system single layer transmission mode 9 TM9 RANK1.

11. The base station of claim 9, wherein the first mode is LTE system transmission mode 5 TM5, and the second mode is LTE system dual-layer transmission mode 9 TM9 RANK2.

12. The base station according to claim 9, further comprising a third adjustment module configured to adjust the weight of the second user equipment in the second adjustment module to realize the second user equipment. The device orthogonalizes the precoding matrix indication information of the first user equipment and adjusts the power of the second user equipment to meet the total power of the first user equipment and the second user equipment after pairing. After constraints,

At the corresponding frequency domain resource unit position of the port of the demodulated pilot signal, the power of the first user equipment is set to 0.

13. The base station according to claim 10, wherein the second adjustment module adjusts the weight of the second user equipment in the following manner: where, w. . is the precoding weight matrix corresponding to the PMI index fed back by the first user equipment in the TM5 mode, _Wl . is the precoding weight matrix corresponding to the PMI index fed back by the second user equipment in the TM9 mode, is the modified precoding weight matrix of the second user equipment, and is the conjugate transposed matrix of w _∞ .

14. The base station according to claim 10, wherein the second adjustment module performs power adjustment on the second user equipment in the following manner to meet the requirements of the first user equipment and the second user equipment after pairing. The total power constraint of user equipment: The weight matrix of the first user equipment after MU power adjustment is: . =—w _m ; The weight matrix of the second user equipment after MU power adjustment is: . = where, w. . is the precoding weight matrix corresponding to the PMI index fed back by the first user equipment in the TM5 mode, _Wl . is the precoding weight matrix corresponding to the PMI index fed back by the second user equipment in the TM9 mode, . is the modified precoding weight matrix of the second user equipment, and is

The conjugate transpose matrix of _W∞ , μ. | means right. Find the 2-norm of a vector. .

15. The base station according to claim 11, characterized in that the second adjustment module adjusts the weight of the second user equipment in the following manner to realize the integration between the second user equipment and the first user. During orthogonalization of the precoding matrix indication information of the device, the weight of the second user equipment is adjusted to 1. = - w ₁₀ w ₀₀ , w _n = w _n - w^w _u w ₀₀ - where, woo is the precoding weight matrix corresponding to the PMI index fed back by the first user equipment in the Γ mode, and ^ is the The precoding matrix weight corresponding to the RANK2 PMI index fed back by the second user equipment in the TM9 mode is, . and is the modified precoding weight matrix of the second user equipment, is the conjugate transposed matrix of w _∞ , and is ^. The conjugate transpose matrix of .

16. The base station according to claim 10, wherein the second adjustment module specifically adjusts the power of the second user equipment in the following manner to meet the requirements of the first user equipment and the third user equipment after pairing. Total power constraints of the two user equipments: The weight matrix of the first user equipment after MU power adjustment is: ^{2 ¼7} °°; The weight matrix of the second user equipment after MU power adjustment is: ^{1Q 2} l . l ,

Wherein, woo is the predetermined value corresponding to the PMI index fed back by the first user equipment in the Γ mode. Coding weight matrices, , ^ are the precoding matrix weights corresponding to the RANK2 PMI index fed back by the second user equipment in the TM9 mode, . and is the modified precoding weight matrix of the second user equipment, . | means right. To find the 2-norm, means to find the 2-norm of .

17. A base station, characterized by including a receiver and a processor;

Wherein, the receiver is configured to receive precoding matrix indication information sent by at least two user equipments; the processor is configured to select and determine that the at least two user equipments are in a pairing state according to a multi-user multiple input multiple output pairing criterion, according to The precoding matrix indication information sent by the first user equipment among the at least two user equipments is assigned to the beam assignment of the transmission data on the downlink physical shared channel PDSCH by the first user equipment in the first mode of the LTE transmission mode. Forming and pairing power adjustment, and beamforming weight adjustment for the second user equipment in the second mode of the LTE transmission mode among the at least two user equipments, so that the second user equipment is connected to the third user equipment. The precoding matrix weights of one user equipment are orthogonal, and the power of the second user equipment is adjusted to meet the total power constraints of the first user equipment and the second user equipment after pairing.