CN102104404A - Multi-user MIMO transmission method in wireless communication system, base station and user terminal - Google Patents

Abstract

The invention discloses a multi-user multiple input multiple output (MU-MIMO) transmission method in a wireless communication system, a base station and a user terminal. The method comprises the following steps that: the base station receives detection pilot frequency SRS of N users to perform channel estimation and acquires downlink channel information according to the channel estimation result and channel reciprocity of the system, wherein N is more than 1; the base station performs quick response (QR) decomposition on the downlink channel information, acquires a multi-user beamforming (MU-BF) matrix P (i) of the ith user from a Q matrix acquired through decomposition, and acquires a downlink single-user beamforming (SU-BF) matrix V (i) of the ith user further, wherein i=1, ...,N; and the base station performs beamforming processing on transmitting data of the ith user according to the MU-BF matrix P (i) and the SU-BF matrix V (i). The method and equipment acquire beamforming matrixes for uplink and downlink MU-MIMO transmission by means of the channel reciprocity of the system and the QR decomposition, and the MU-MIMO transmission performance can be improved.

Description

The transmission method of multiuser MIMO, base station and user terminal in the wireless communication system

Technical field

The present invention relates to wireless communication field, relate in particular to multi-user's multiple-input and multiple-output (MU-MIMO) in the wireless communication system (such as the LTE-A system) transmission method, be used for the base station and the user terminal of MU-MIMO transmission.

Background technology

Multiple-input and multiple-output (MIMO) technology has become one of key technology of the system of broadband wireless communication that comprises 3GPP Long Term Evolution (LTE) because can effectively improve the spectrum efficiency of Radio Link.Can according to support a plurality of users simultaneously on identical running time-frequency resource, the MIMO technology can be divided into Single User MIMO (SU-MIMO) and multiuser MIMO (MU-MIMO) again.Wherein, MU-MIMO has more advantages, as support user antenna configuration more flexibly, stronger to the adaptive capacity of channel condition, have a multi-user diversity gain etc.MU-MIMO is suitable for for the uplink downlink of cellular system, but descending MU-MIMO has higher requirement to the channel condition information (CSIT) of emission pusher side, promptly requires base station (eNB) must obtain each user's (UE) descending channel information.The 2 kinds of situations of common branch of obtaining of CSIT:

For time division duplex (TDD) system, because uplink downlink takies identical frequency resource, so has reciprocity between the up-downgoing wireless channel, can know down channel by inference according to up channel easily, vice versa.

For Frequency Division Duplexing (FDD) (FDD) system, because uplink downlink takies different frequency resources, scarcely has reciprocity between the up-downgoing wireless channel, the obtaining of the more difficult acquisition of reciprocity in the FDD system, so CSIT in other words mostly by feedback channel.Certainly, in order to reduce feedback quantity, can be by code book design or quantification technique.

When specific implementation, SU-MIMO and MU-MIMO need carry out preliminary treatment according to CSIT usually to transmitting, (aforesaid operations is called precoding or beam forming for MUI, purpose multi-userinterference) to reach match channels respectively and to eliminate multi-user interference.Because different technology scene descriptions custom is different, may be used alternatingly this two kinds of titles among the application, but the implication of the two is identical.

At present, the up design of 3GPP LTE Rel-8 only can virtual support MU-MIMO, promptly can support a plurality of single antenna UE to send data simultaneously; Descending design then mainly is to be optimized at SU-MIMO, and is very limited to the support of MU-MIMO, can't support the transmission of many UE and every UE multiple data stream.In addition, for the simplified system design, LTE Rel-8 has adopted almost completely identical design to FDD and TDD, promptly all adopts the beam forming based on code book, the reciprocity of not utilizing wireless channel to exist.

Along with the standard formulation work of LTE Rel-8 is drawn to a close, 3GPP has started the research work of LTE-A in year in 2008.LTE-A is the follow-up evolution of LTE, systematic function is had higher requirement, such as requiring the LTE-A system can support the MU-MIMO transmission of many UE and every UE multiple data stream.So, how in the LTE-A system, to support up-downgoing MU-MIMO to become a research focus effectively.Have, in the technical discussion at LTE-A, the reciprocity that how to make full use of wireless channel supports the beam forming of non-code book just receiving increasing concern, especially for the TDD system again.

At the problems referred to above, modal way is that uplink downlink to cellular system adopts independently MU-MIMO transmission in the prior art, wherein the simplest implementation (scheme one) is that descending MU-MIMO sends based on a minute block diagonalization (BD), and up MU-MIMO does not process and only adopt Multiuser Detection (MUD) reception at transmitting terminal.Though it is simple that scheme one realizes,, further do not utilize the characteristic of wireless channel, thereby sacrificed spectrum efficiency to a certain extent because how a consideration eliminates the phase mutual interference between the multi-user.

On the basis of scheme one, prior art has also proposed a kind of associating MU-MIMO scheme (scheme two) at TDD system uplink downlink.That is: descending MU-MIMO carries out SVD to the equivalent channel of each UE and decomposes by after the BD criterion elimination multi-user interference, thereby each UE is realized the feature transmission respectively; Use same wireless channel to carry out under the prerequisite of transfer of data in up-downgoing, up MU-MIMO also can realize the feature transmission of each UE.As can be seen, scheme two realizes the orthogonal transmission of a plurality of data flow of a plurality of users of up-downgoing simultaneously, and spectrum efficiency is improved.But the complexity that SVD decomposes is very high, and numerical stability is relatively poor, makes the realization of scheme two have certain obstacle.Simultaneously, scheme two requires up-downgoing must use identical wireless channel to carry out transfer of data, and this can not satisfy in the cellular system of reality sometimes, has also limited the realizability of up MU-MIMO in the scheme two.

Summary of the invention

In view of this, main purpose of the present invention is to provide a kind of MU-MIMO transmission method, base station and user terminal.

For achieving the above object, technical scheme of the present invention specifically is achieved in that

The transmission method of multi-user's multiple-input and multiple-output MU-MIMO in a kind of wireless communication system comprises:

The base station receives the detecting pilot frequency SRS that sends from N user terminal UE and carries out channel estimating, and generates the descending channel information matrix according to the channel reciprocity of channel estimation results and described system, and wherein said N is greater than 1;

The QR decomposition is carried out to the descending channel information matrix of described generation in described base station, obtains the multi-user beam moulding MU-BF matrix P of i UE from the Q matrix that decomposition obtains ⁽ⁱ⁾, and further obtain descending single user wave beam moulding SU-BF matrix V of i UE ⁽ⁱ⁾, i=1 wherein ..., N;

Described base station is according to described MU-BF matrix P ⁽ⁱ⁾With described descending SU-BF matrix V ⁽ⁱ⁾, the emission data of i UE are carried out beam forming handle.

This method further comprises:

Described base station is according to MU-BF matrix and the descending SU-BF matrix of i UE, the special pilot frequency for user of this UE is carried out the launching beam forming processes after, send to described UE.

This method further comprises:

I UE receives the descending pilot frequency that described base station sends and carries out channel estimating, obtains the descending channel information matrix at this UE;

This UE carries out QR to described descending channel information matrix and decomposes, and obtains the uplink single user beam forming SU-BF matrix U of self from the Q matrix that decomposition obtains ⁽ⁱ⁾

According to this up SU-BF matrix the emission data being carried out beam forming handles.

Described UE carries out QR to the descending channel information matrix and decomposes and to obtain up SU-BF matrix and comprise:

The special pilot frequency for user of i UE reception base station transmission carries out channel estimating, obtains descending equivalent channel matrix;

This UE carries out QR to described descending equivalent channel matrix and decomposes, and the Q matrix that decomposition is obtained is as the first up SU-BF matrix of described UE.

Described UE carries out QR to the descending channel information matrix and decomposes and to obtain up SU-BF matrix and comprise:

The cell-specific pilot tone of i UE reception base station transmission is carried out channel estimating, obtains the down physical channel matrix, and obtains the uplink physical channel matrix according to channel reciprocity;

This UE carries out QR to described uplink physical channel matrix and decomposes, and the Q matrix that obtains from decomposition obtains the second up SU-BF matrix of described UE.

This method further comprises:

This UE carries out conjugate transpose to up SU-BF matrix;

According to the conjugate transpose of described up SU-BF matrix the reception data of this UE are carried out carrying out MIMO and detecting after beam forming handles.

This method further comprises: this UE is according to described up SU-BF matrix, uplink demodulation pilot tone DMRS is carried out the launching beam forming processes after, send to described base station.

This method further comprises:

Conjugate transpose is carried out to MU-BF matrix and the descending SU-BF matrix of i UE in described base station;

According to the conjugate transpose of the MU-BF matrix of described UE the reception data of this base station are carried out multi-user interference and eliminate MUI, obtain the reception data of i UE, after utilizing the conjugate transpose of descending SU-BF matrix that the reception data of this UE are handled again, carry out MIMO and detect.

Described base station obtains descending single user wave beam moulding SU-BF matrix V of i UE ⁽ⁱ⁾Comprise:

Described base station is according to the down physical channel matrix H of i UE ⁽ⁱ⁾And MU-BF matrix P ⁽ⁱ⁾Obtain H ⁽ⁱ⁾P ⁽ⁱ⁾, and to H ⁽ⁱ⁾P ⁽ⁱ⁾Carry out QR and decompose, obtain the descending SU-BF matrix V of described UE ⁽ⁱ⁾

Described UE obtains the uplink single user beam forming SU-BF matrix U of self ⁽ⁱ⁾Comprise:

UE is with the uplink physical channel matrix H _UL ⁽ⁱ⁾Conjugate transpose H with this uplink physical channel matrix _UL ^{(i) H}Multiply each other and obtain H _UL ^{(i) H}H _UL ⁽ⁱ⁾, again with H _UL ^{(i) H}H _UL ⁽ⁱ⁾And U _T-1 ⁽ⁱ⁾Decomposition obtains up SU-BF matrix U through QR after multiplying each other _t ⁽ⁱ⁾

A kind of base station that is used for multi-user's multiple-input and multiple-output MU-MIMO transmission comprises:

Channel estimating unit is used to carry out the uplink channel information that channel estimating obtains an above user terminal UE, and obtains the descending channel information matrix according to channel reciprocity;

The QR resolving cell is used for that described descending channel information matrix is carried out QR and decomposes, and obtains the multi-user beam moulding MU-BF matrix of each UE from the Q matrix that decomposition obtains, and further obtains descending single user wave beam moulding SU-BF matrix of each UE;

The launching beam forming unit is used for MU-BF matrix and descending SU-BF matrix according to each UE, the emission data of corresponding UE are carried out beam forming handle, and the antenna of delivering to this base station transmits.

The R matrix that described QR resolving cell is further used for decomposition is obtained offers the MIMO detecting unit;

Described MIMO detecting unit is used for according to described R matrix the reception data of antenna being carried out MIMO and detects, and recovers the transmission data of each UE.

Described QR resolving cell is further used for the MU-BF matrix of each UE and descending SU-BF matrix are carried out conjugate transpose, offers the received beam forming unit;

Described received beam forming unit, be used for the reception data of described antenna being carried out multi-user interference and eliminate MUI according to the conjugate transpose of the MU-BF matrix of each UE, obtain the reception data of each UE, after utilizing the conjugate transpose of descending SU-BF matrix that the reception data of corresponding UE are handled again, send to described MIMO detecting unit.

Described QR resolving cell is further used for the R matrix that obtains according to decomposition, and the data streams of a described above UE is carried out Adaptive Modulation and Coding AMC control.

Described QR resolving cell is used for the down physical channel matrix H according to each UE ⁽ⁱ⁾And MU-BF matrix P ⁽ⁱ⁾Obtain H ⁽ⁱ⁾P ⁽ⁱ⁾, and to H ⁽ⁱ⁾P ⁽ⁱ⁾Carry out QR and decompose, obtain the descending SU-BF matrix V of each UE ⁽ⁱ⁾, described i is from 1 arbitrary integer to number of users N.

Described channel estimating unit is used for carrying out channel estimating according to the detecting pilot frequency SRS that each UE sends, and perhaps the uplink demodulation pilot tone DMRS that sends according to each UE obtains uplink channel information, and obtains the descending channel information matrix according to channel reciprocity.

Described launching beam forming unit is further used for according to the MU-BF matrix of each UE and descending SU-BF matrix, the special pilot frequency for user of issuing each UE is carried out beam forming handle.

A kind of user terminal UE that is used for multi-user's multiple-input and multiple-output MU-MIMO transmission comprises:

Channel estimating unit is used to carry out channel estimating, obtains the descending channel information matrix of this UE;

The QR resolving cell is used for that described descending channel information matrix is carried out QR and decomposes, and obtains the uplink single user beam forming SU-BF matrix of this UE from the Q matrix that decomposition obtains;

The launching beam forming unit is used for according to the up SU-BF matrix of this UE the emission data being carried out the beam forming processing, and sends from the antenna of this UE.

Described channel estimating unit is used for carrying out channel estimating according to the special pilot frequency for user that the base station sends, and obtains descending equivalent channel matrix;

Described QR resolving cell is used for that described descending equivalent channel matrix is carried out QR and decomposes, and the Q matrix that decomposition is obtained is as the first up SU-BF matrix of this UE.

Described channel estimating unit is used for carrying out channel estimating according to the cell-specific pilot tone that the base station sends, and obtains the down physical channel matrix, and obtains the uplink physical channel matrix according to channel reciprocity;

Described QR resolving cell is used for that described uplink physical channel matrix is carried out QR and decomposes, and the Q matrix that obtains from decomposition obtains the second up SU-BF matrix of this UE.

The R matrix that described QR resolving cell is further used for decomposition is obtained offers the MIMO detecting unit;

Described MIMO detecting unit is used for according to described R matrix the reception data of this UE being carried out MIMO and detects.

Described QR resolving cell is further used for the up SU-BF matrix of this UE is carried out conjugate transpose, offers the received beam forming unit;

Described received beam forming unit after being used for according to the conjugate transpose of described up SU-BF matrix the reception data of this UE being handled, sends to described MIMO detecting unit.

Described QR resolving cell is further used for the R matrix that obtains according to decomposition, and the above data streams of described UE is carried out Adaptive Modulation and Coding AMC control.

Described launching beam forming unit is further used for the up SU-BF matrix according to this UE, uplink demodulation pilot tone DMRS is carried out beam forming handle.

As seen from the above technical solution, the beam forming matrix (comprising MU-BF matrix and SU-BF matrix) that this MU-MIMO transmission method of the present invention is lower by complexity, numerical stability QRD calculating preferably is used for up-downgoing MU-MIMO transmission, and on this basis transceiver architecture (base station and user terminal) is simplified and optimized, be beneficial to Project Realization.As can be seen, the present invention makes full use of the reciprocity of wireless channel in the communication system, design the MU-MIMO transmission plan of non-code book for the uplink downlink of LTE-A system, be used to support the transmission of multi-user's multiple data stream, the beam forming of this non-code book can be realized wireless channel is mated more accurately to promote transmission performance, need not to feed back pre-coding matrix index value (PMI) simultaneously, thereby can reduce feedback overhead to improve spectrum efficiency.

Description of drawings

Fig. 1 is the system model of MU-MIMO in the one embodiment of the invention;

Fig. 2 is the flow chart of MU-MIMO up-downgoing transmission when the up-downgoing resource allocation is identical in the one embodiment of the invention;

Fig. 3 is the schematic diagram of eNB side QRD iteration;

Fig. 4 is the up-downgoing resource allocation flow chart of MU-MIMO downlink transfer simultaneously not in the one embodiment of the invention;

Fig. 5 is the up-downgoing resource allocation flow chart of MU-MIMO uplink simultaneously not in the one embodiment of the invention;

Fig. 6 is the schematic diagram of UE side QRD iteration;

Fig. 7 is the structural representation that is used for the base station of MU-MIMO transmission in the one embodiment of the invention;

Fig. 8 is the structural representation that is used for the user terminal of MU-MIMO transmission in the one embodiment of the invention;

Fig. 9 is prior art and the comparison schematic diagram of the embodiment of the invention on descending throughput performance;

Figure 10 is prior art and the comparison schematic diagram of the embodiment of the invention on up throughput performance.

Embodiment

For making purpose of the present invention, technical scheme and advantage clearer, below with reference to the accompanying drawing embodiment that develops simultaneously, the present invention is described in more detail.

In one embodiment of the invention, MU-MIMO system for transmitting model as shown in Figure 1, this model is considered 1 base station (eNB) 2 users' (UE) situation, these 2 UE are isolated users of selecting by multi-subscriber dispatching.This eNB has 4 antennas, and each UE has 2 antennas.Need to prove,, before carrying out the MU-MIMO transmission, should pick out the separate user of several space channels, participate in the MU-MIMO transmission by the multi-subscriber dispatching algorithm owing to may have a lot of users in the cellular system.In the following description, only consider that multi-subscriber dispatching is finished after, how to carry out MU-MIMO transmission between the isolated user.

At system model shown in Figure 1, the signal model of descending MU-MIMO transmission is expressed as:

$y_{\mathrm{DL}}^{\left(i\right)}=H^{\left(i\right)}\underset{k=1}{\overset{2}{\mathrm{\Σ}}}{P}^{\left(k\right)}{V}^{\left(k\right)}{d}_{\mathrm{DL}}^{\left(k\right)}+n_{\mathrm{DL}}^{\left(i\right)},i=\mathrm{1,2}---\left(1\right)$

Wherein:

y _DL ⁽ⁱ⁾It is the received signal vector (2*1) of i UE;

H ⁽ⁱ⁾Be down channel matrix (2*4) from eNB to i UE;

P ^(k)It is multi-user beam moulding (MU-BF) matrix (4*2) of k UE;

V ^(k)It is descending single user wave beam moulding (SU-BF) matrix (2*2) of k UE;

d _DL ^(k)It is the downlink data flow vector (2*1) of i UE;

n _DL ⁽ⁱ⁾It is additive white Gaussian noise (AWGN, the Additive White GaussianNoise) noise vector (2*1) of i UE.

The allocation of radio resources of supposing uplink downlink is identical, and the signal model of then up MU-MIMO transmission can be expressed as:

$y_{\mathrm{UL}}=\underset{i=1}{\overset{2}{\mathrm{\Σ}}}{\left[H^{\left(i\right)}\right]}^H{U}^{\left(i\right)}{d}_{\mathrm{UL}}^{\left(i\right)}+n_{\mathrm{UL}}---\left(2\right)$

Wherein:

y _ULReceived signal vector (4*1) for eNB;

[H ⁽ⁱ⁾] ^HBe up channel matrix (4*2) from i UE to eNB;

U ⁽ⁱ⁾It is uplink single user beam forming (SU-BF) matrix (2*2) of i UE;

d _UL ⁽ⁱ⁾It is the upstream data flow vector (2*1) of i UE;

n _ULAWGN noise vector (4*1) for eNB.

It is pointed out that in the TDD system, when uplink downlink takies identical wireless channel, have reciprocity between the wireless channel of up-downgoing, if the down channel matrix notation promptly from eNB to i UE is H ⁽ⁱ⁾, the up channel matrix from i UE to eNB just can be expressed as [H so ⁽ⁱ⁾] ^T, that is the up-downgoing channel matrix satisfies transposition relation.In an embodiment of the present invention, in order to simplify the calculating of up-downgoing SU-BF matrix, need make and satisfy the conjugate transpose relation between the up-downgoing channel matrix, if the down channel matrix notation promptly from eNB to i UE is H ⁽ⁱ⁾, the up channel matrix from i UE to eNB then is expressed as [H so ⁽ⁱ⁾] ^TConcern in order to satisfy this conjugate transpose, only need before the upward signal emission and respectively carry out a conjugate operation before the processing of up received signal to get final product.

Based on the model of Fig. 1, under the identical prerequisite of uplink downlink allocation of radio resources, the flow process of up-downgoing associating MU-MIMO transmission may further comprise the steps as shown in Figure 2:

Step 201: a plurality of UE (suppose that number of users is N, N is greater than 1) send detecting pilot frequency (SRS) to eNB, and wherein i UE is UE _i, i=1 ..., N.In the present embodiment, N=2.

Step 202:eNB carries out channel estimating according to SRS, knows the uplink physical channel of a plurality of UE, knows down physical channel by inference according to channel reciprocity then $H_{\mathrm{DL}}\stackrel{\mathrm{\Δ}}{=}\left[\begin{array}{c}{H}^{\left(1\right)}\\ H^{\left(2\right)}\end{array}\right].$

Step 203:eNB carries out 4*4QR and decomposes (QRD, QR decomposition), is each UE calculating MU-BF matrix P separately ⁽ⁱ⁾, i=1,2.Wherein, the QR decomposition is also referred to as the orthogonal matrix trigonometric ratio, is about to certain matrix A and is decomposed into an orthogonal matrix Q and a upper triangular matrix R.

With P ⁽²⁾Be example, to H _DLConjugate transpose H ^HCarry out QRD, obtain H ^H=QR.Wherein, Q is the unitary matrix of 4*4, and R is the upper triangular matrix of 4*4, preceding 2 of Q is listed as with back 2 row is written as 2 submatrixs, i.e. Q=[Q ⁽¹⁾Q ⁽²⁾].So, P ⁽²⁾=Q ⁽²⁾Be the MU-BF matrix of UE2, satisfy H ⁽¹⁾P ⁽²⁾=0 _{2 * 2}

Step 204:eNB is according to UE _iDown physical channel H ⁽ⁱ⁾With MU-BF matrix P ⁽ⁱ⁾Calculate H ⁽ⁱ⁾P ⁽ⁱ⁾, i=1,2, at H ⁽ⁱ⁾P ⁽ⁱ⁾, i=1,2 carry out the QRD iteration of 2*2, obtain UE _iDescending SU-BF matrix V ⁽ⁱ⁾

Concrete iterative process is seen Fig. 3.Along with the increase of iterations, UE _iA plurality of data flow between interference reduction, but calculation delay also can correspondingly increase, common 1 iteration can reach better performance.

Step 205:eNB uses the BF matrix P of cascade ⁽ⁱ⁾V ⁽ⁱ⁾The emission data are carried out beam forming (Tx-BF).

Step 206:eNB also carries out same beam forming to special pilot frequency for user (UE-specific RS).

Step 207:eNB sends the Downlink Control Information (DCI, Downlink Control Information) that is used for transfer of data to each UE.It may be noted that this step is optional.

Step 208:eNB sends the special pilot frequency for user and the data of process beam forming to each UE.

Step 209:UE carries out channel estimating according to the special pilot frequency for user that receives, and obtains descending equivalent channel ${\tilde{H}}_{\mathrm{DL}}^{\left(i\right)}=H^{\left(i\right)}{P}^{\left(i\right)}{V}^{\left(i\right)}.$

Step 210:UE carries out 2*2QRD to descending equivalent channel, and the Q battle array that obtains is the first up SU-BF matrix U of this UE ₁ ⁽ⁱ⁾That is to say the first up SU-BF matrix U ₁ ⁽ⁱ⁾Be according to descending equivalent channel Obtain.

Step 211: with the first up SU-BF matrix U of UE ₁ ⁽ⁱ⁾Conjugate transpose [U ₁ ⁽ⁱ⁾] ^HAs the received beam moulding (Rx-BF) of this UE, obtain the reception data behind the beam forming

It may be noted that this step is optional.

${\tilde{d}}_{\mathrm{DL}}^{\left(i\right)}={\left[U^{\left(i\right)}\right]}^H{y}_{\mathrm{DL}}^{\left(i\right)}=R_{\mathrm{DL}}^{\left(i\right)}{d}_{\mathrm{DL}}^{\left(i\right)}+{\tilde{n}}_{\mathrm{DL}}^{\left(i\right)}$

Wherein, $R_{\mathrm{DL}}^{\left(i\right)}=\left[\begin{array}{cc}{r}_{\mathrm{DL},11}^{\left(i\right)}& r_{\mathrm{DL},12}^{\left(i\right)}\\ 0& r_{\mathrm{DL},22}^{\left(i\right)}\end{array}\right],$ This R _DL ⁽ⁱ⁾It is descending equivalent channel

Carry out the upper triangular matrix that 2*2QRD obtains afterwards; d _DL ⁽ⁱ⁾It is the downlink data flow vector (2*1) of i UE; ${\tilde{n}}_{\mathrm{DL}}^{\left(i\right)}={\left[U^{\left(i\right)}\right]}^H{n}_{\mathrm{DL}}^{\left(i\right)}.$

Step 212:UE carries out the MIMO detection to receiving data.

If execution in step 211 is then passed through after the received beam moulding, UE is right

Carrying out MIMO detects.The down link of considering the LTE-A system is based on OFDM (OFDMA), R _DL ⁽ⁱ⁾This three-legged structure of going up can support multiple different MIMO detection algorithm, comprise QR-SIC, QRM-MLD, SD etc.It is pointed out that the operation of received beam moulding is optionally, therefore also can be directly to y in MU-MIMO transmission shown in Figure 2 _DL ⁽ⁱ⁾Carrying out ZF/MMSE detection or ML detects.

Step 213:UE uses the first up SU-BF matrix U ₁ ⁽ⁱ⁾Send data, and uplink demodulation pilot tone (DMRS) is carried out same beam forming.

Step 214:UE will send to eNB through DMRS and the data that beam forming is handled.

Step 215:eNB uses the conjugate transpose [P of MU-BF matrix ⁽ⁱ⁾] ^HCarry out multi-user interference (MUI) elimination, thereby isolate the upstream of different UEs.It may be noted that this step is optional.

Step 216:eNB carries out channel estimating according to DMRS.

Step 217-218:eNB obtains the descending SU-BF matrix V of UE by QRD ⁽ⁱ⁾, and use its conjugate transpose [V ⁽ⁱ⁾] ^HCarry out the received beam moulding, obtain the reception data behind the beam forming

It may be noted that these two steps also are optional.

${\tilde{d}}_{\mathrm{DL}}^{\left(i\right)}={\left[V^{\left(i\right)}\right]}^H{\left[P^{\left(i\right)}\right]}^H{y}_{\mathrm{UL}}=R_{\mathrm{UL}}^{\left(i\right)}{d}_{\mathrm{UL}}^{\left(i\right)}+{\tilde{n}}_{\mathrm{UL}}^{\left(i\right)}$

Wherein, $R_{\mathrm{UL}}^{\left(i\right)}=\left[\begin{array}{cc}{r}_{\mathrm{UL},11}^{\left(i\right)}& r_{\mathrm{UL},12}^{\left(i\right)}\\ 0& r_{\mathrm{UL},22}^{\left(i\right)}\end{array}\right],$ This R _UL ⁽ⁱ⁾It is the up equivalent channel of this moment ${\tilde{H}}_{\mathrm{UL}}^{\left(i\right)}={\left[V^{\left(i\right)}\right]}^H{\left[P^{\left(i\right)}\right]}^H{\left[H^{\left(i\right)}\right]}^H{U}^{\left(i\right)}$ Carry out the upper triangular matrix that obtains behind the 2*2QRD; d _UL ⁽ⁱ⁾It is the upstream data flow vector (2*1) of i UE; ${\tilde{n}}_{\mathrm{UL}}^{\left(i\right)}={\left[V^{\left(i\right)}\right]}^H{\left[P^{\left(i\right)}\right]}^H{n}_{\mathrm{UL}}.$ The up link of considering the LTE-A system is based on single-carrier frequency division multiple access (SC-FDMA), R _UL ⁽ⁱ⁾This three-legged structure of going up can support MIMO detection algorithm based on QR-SIC.

Step 219:eNB utilizes R _UL ⁽ⁱ⁾Carrying out MIMO detects.

Need to prove, in flow process shown in Figure 2, have two kinds of situations after the step 214:

(1) if eNB carries out up joint-detection, just need not to carry out the operation of received beam moulding.So, eNB carries out channel estimating according to DMRS and obtains up equivalent channel ${\tilde{H}}_{\mathrm{UL}}^{\left(i\right)}={\left[H^{\left(i\right)}\right]}^H{U}^{\left(i\right)},$ Then directly to y _ULCarrying out the ZF/MMSE detection gets final product.

(2), then use the conjugate transpose [P of MU-BF matrix if eNB carries out up independent detection ⁽ⁱ⁾] ^HIsolate the upstream of different UEs, re-use descending SU-BF matrix V ⁽ⁱ⁾Conjugate transpose [V ⁽ⁱ⁾] ^HCarry out the received beam moulding, right then

Carrying out MIMO detects.

So far, the transmission course of the once complete up MU-MIMO of descending MU-MIMO+ is finished.Wherein, eNB uses MU-BF matrix P ⁽ⁱ⁾With descending SU-BF matrix V ⁽ⁱ⁾Carry out Tx-BF, each UE that participates in the MU-MIMO transmission uses the first up SU-BF matrix U ₁ ⁽ⁱ⁾Carry out Tx-BF.Alternatively, each UE can also use the conjugate transpose of the first up SU-BF matrix to carry out Rx-BF, and eNB also can use the conjugate transpose of MU-BF matrix and descending SU-BF matrix to carry out Rx-BF.

Under the prerequisite that channel condition does not change, the MU-MIMO of up-downgoing transmission can be based on the P that has obtained ⁽ⁱ⁾, V ⁽ⁱ⁾And U ⁽ⁱ⁾, and

(seeing step 209) and (seeing step 216) proceeded down.When channel condition changes, then need to restart to take turns flow process shown in Figure 2.

In said process, the concrete iteration of step 204 comprises: matrix H as shown in Figure 3 ⁽ⁱ⁾P ⁽ⁱ⁾One tunnel process Hermitian deferring device 301 obtains P ^{(i) H}H ^{(i) H}, another road is through matrix multiplier 302 Hes $V_{t-1}^{\left(i\right)}(V_0^{\left(i\right)}=I_{2\×2})$ Multiply each other and obtain H ⁽ⁱ⁾P ⁽ⁱ⁾V _T-1 ⁽ⁱ⁾H ⁽ⁱ⁾P ⁽ⁱ⁾V _T-1 ⁽ⁱ⁾Through obtaining U behind the QR decomposer 303 _T-1 ⁽ⁱ⁾, U _T-1 ⁽ⁱ⁾Through matrix multiplier 304 and P ^{(i) H}H ^{(i) H}Multiply each other and obtain P ^{(i) H}H ^{(i) H}U _T-1 ⁽ⁱ⁾P ^{(i) H}H ^{(i) H}U _T-1 ⁽ⁱ⁾Obtain V respectively through QR decomposer 305 _t ⁽ⁱ⁾And R _t ⁽ⁱ⁾According to the iterations that sets in advance, V _t ⁽ⁱ⁾Can also conduct $V_{t-1}^{\left(i\right)}(V_0^{\left(i\right)}=I_{2\×2})$ Feed back to matrix multiplier 302.

Up-downgoing MU-MIMO transmission course shown in Figure 2 requires the allocation of radio resources of uplink downlink identical.When the allocation of radio resources of uplink downlink not simultaneously, the transmission course of descending MU-MIMO and up MU-MIMO should independently be carried out, and respectively as shown in Figure 4 and Figure 5, but still can utilize the reciprocity of up-downgoing wireless channel.

As seen from Figure 4, the resource allocation difference brings influence for descending MU-MIMO transmission course, and the step 201-212 among this process and Fig. 2 is similar, repeats no more herein.Wherein, optionally step (such as step 407,410,411) is shown in broken lines.

Fig. 5 is the up-downgoing resource allocation transmission course of up MU-MIMO simultaneously not in the one embodiment of the invention, and this process and Fig. 2 are different, specifically comprise:

Step 501-504 is referring to the corresponding step among Fig. 2.Particularly, step 501 and step 201 are similar, and step 502 and step 202 are similar, and step 503 and step 207 are similar, and step 504 and step 208 are similar, and different is, and eNB sends among Fig. 5 is cell-specific pilot tone (Cell-specific RS).

Step 505:UE carries out channel estimating according to the cell-specific pilot tone that eNB sends, and knows the down physical channel H of 2*4 ⁽ⁱ⁾, know the uplink physical channel H of 4*2 then by inference according to channel reciprocity _UL ⁽ⁱ⁾Be [H ⁽ⁱ⁾] ^T

Step 506: according to this uplink physical channel matrix H _UL ⁽ⁱ⁾, UE carries out the 2*2QRD iteration and obtains the second up SU-BF matrix U ₂ ⁽ⁱ⁾(can be expressed as U again _Phy ⁽ⁱ⁾), this iteration can be controlled by different iterationses is set.It should be noted that the second up SU-BF matrix U of this moment ₂ ⁽ⁱ⁾Calculate according to uplink physical channel, be different among Fig. 2 and calculate the first up SU-BF matrix U according to descending equivalent channel ₁ ⁽ⁱ⁾

Step 507:UE uses the second up SU-BF matrix U ₂ ⁽ⁱ⁾Carry out data and send, and DMRS also needs to carry out same launching beam moulding.

DMRS behind the step 508:UE transmission beam forming and data are to eNB.

Step 509-510:eNB carries out channel estimating according to DMRS and obtains equivalent channel, and unites ZF/MMSE and detect.

In addition, the concrete iteration of step 506 comprises as shown in Figure 6: with the uplink physical channel matrix H _UL ⁽ⁱ⁾One the road delivers to Hermitian deferring device 601 obtains H _UL ^{(i) H}, matrix multiplier 602 and H are delivered in another road _UL ^{(i) H}Multiply each other and obtain H _UL ^{(i) H}H _UL ⁽ⁱ⁾With H _UL ^{(i) H}H _UL ⁽ⁱ⁾Deliver to matrix multiplier 603 and U _T-1(U ₀=I) multiply each other after, obtain U through QR decomposer 604 _tWith U _tAs U _T-1(U ₀=I) feed back to matrix multiplier 602.

Certainly, the described method of the embodiment of the invention can directly be generalized to the situation of any number of users and antenna number, as long as satisfy restriction relation (3).

$n_{\mathrm{eNB}}\≥\underset{i}{\mathrm{\Σ}}{n}_{\mathrm{UEi}}---\left(3\right)$

Wherein, n _ENBBe the antenna number of eNB, n _UEiBe the antenna number of i UE, i 〉=1.

As can be seen, up-downgoing MU-MIMO transmission method based on QRD provided by the invention, use the reciprocity of (such as TDD or FDD system) up-downgoing interchannel in the system, thereby on the uplink downlink of LTE-A system, can effectively support the quadrature or the accurate orthogonal transmission of multi-user's multiple data stream.

Further, embodiments of the invention provide a kind of MU-MIMO of being used for the base station of transmission, comprising: many antennas, switch element 701, channel estimating unit 702, QR resolving cell 703, launching beam forming unit 704, eliminate processing unit 707 for MIMO detecting unit, received beam forming unit 706, the MUI of each UE setting.In the present embodiment, setting eNB has 4 antennas, and the number of users N that participates in the MU-MIMO transmission is 2, and each user is provided with 2 antennas, and then the MIMO detecting unit comprises: the MIMO detecting unit 7051 of UE1 and the MIMO detecting unit 7052 of UE2.

During real work, channel estimating unit 702 offers QR resolving cell 703 with channel estimation results, is decomposed by 703 pairs of channel matrixes of QR resolving cell, obtains each user's MU-BF matrix and descending SU-BF matrix, is P in the present embodiment ⁽¹⁾, P ⁽²⁾, V ⁽¹⁾, V ⁽²⁾, offer launching beam forming unit 704.Further, QR resolving cell 703 provides V ^{(1) H}And V ^{(2) H}Give received beam forming unit 706, P is provided ^{(1) H}And P ^{(2) H}Eliminate processing unit 707 to MUI.Further, the R matrix that will generate during QR resolving cell 703 will decompose offers the MIMO detecting unit, detects so that carry out MIMO.Further, QR resolving cell 703 also will generate AMC control signal (such as utilizing the R matrix that generates in the decomposition), data streams be controlled, so that adapt to different channel conditions.

During data transmission, launching beam forming unit 704 uses V ⁽¹⁾Data streams 1 and data streams 2 to UE1 are carried out the processing of SU-BF matrix, use P again ⁽¹⁾Carry out the MU-BF matrix and handle, obtain 4 circuit-switched data stream a1-d1.Similarly, launching beam forming unit 704 uses V ⁽²⁾Data streams 1 and data streams 2 to UE2 are carried out the processing of SU-BF matrix, use P again ⁽²⁾Carry out the MU-BF matrix and handle, also obtain 4 circuit-switched data stream a2-d2.Will UE1 and the data flow superposition that obtains after through the launching beam moulding of UE2 after output to antenna, such as delivering to certain root antenna transmission behind the data flow a2 superposition with the data flow a1 of UE1 and UE2.

During Data Receiving, receive 4 circuit-switched data stream a3-d3 from 4 antennas, the MUI that every circuit-switched data flow point is not delivered to a plurality of users eliminates processing unit 707, delivers to received beam forming unit 706 again.Such as, the MUI that data flow a3 is delivered to UE1 and UE2 eliminates processing unit, uses P respectively ^{(1) H}And P ^{(2) H}Eliminate MUI, use the conjugate transpose V of SU-BF more respectively ^{(1) H}And V ^{(2) H}Carry out the received beam moulding.It may be noted that MUI eliminates processing unit 707 and received beam forming unit 706 is that eNB goes up optional unit.Afterwards, through the processing of MIMO detecting unit, recover the data streams of UE.

Further, embodiments of the invention provide a kind of MU-MIMO of being used for the user terminal of transmission, comprising: many antennas, switch element 801, channel estimating unit 802, QR resolving cell 803, launching beam forming unit 804, MIMO detecting unit 805, received beam forming unit 806.Wherein, launching beam forming unit 804 comprises SU-BF processing unit 8041, and received beam forming unit 806 comprises SU received beam forming unit 8061.It may be noted that received beam forming unit 806 is optional on user terminal.

QR resolving cell 803 decomposes channel matrix according to the channel estimation results that channel estimating unit provides, and obtains up SU-BF matrix U ⁽ⁱ⁾(can be the first up SU-BF matrix U ₁ ⁽ⁱ⁾, also can be the second up SU-BF matrix U ₂ ⁽ⁱ⁾), and further obtain the conjugate transpose [U of up SU-BF matrix ⁽ⁱ⁾] ^H, offer SU-BF processing unit 8041 and SU received beam forming unit 8061 respectively.Further, QR resolving cell 803 offers MIMO detecting unit 805 with the R matrix that decomposition obtains, and perhaps is used for AMC control.

As can be seen, method of the present invention, base station and user terminal need not the SVD by high complexity when carrying out the MU-MIMO transmission, even when not adopting MMSE to detect, matrix inversion that also can high complexity, but realize beam forming by the lower QRD of complexity.On the one hand, the unitary matrix that QRD produces can be used for MU-BF and SU-BF, and can be used to transmit and receive beam forming simultaneously; On the other hand, the upper triangular matrix of QRD generation can be used for MIMO detection and Adaptive Modulation and Coding (AMC).For example, can obtain the channel gain of each (standard) orthogonal channel according to the diagonal entry of upper triangular matrix, can calculate signal to noise ratio (snr) in conjunction with noise power, be that each (standard) orthogonal channel is selected suitable modulation coding mode (MCS) in view of the above, be included in and select to close this data flow when channel condition is not enough to support other MCS of lowermost level, thereby realize the adaptively changing of transmission exponent number (Rank).

Utilize the simulation parameter shown in the table one, the method that the embodiment of the invention provides is carried out link level simulation.In this emulation, suppose the current multi-subscriber dispatching of having finished, the wireless channel of 2 UE remains independence, and each UE supports 2 data flow.If considered SU-BF in MU-BF, 2 data flow points do not adopt 64QAM and 4QAM modulation so; If do not consider SU-BF in MU-BF, 2 data flow adopt identical modulation system so, are 16QAM.In addition, the supposition ideal communication channel is estimated in this emulation, and beam forming is based on that average channel (rather than instantaneous channel of each subcarrier) in the Resource Block carries out, though this can cause decreased performance to a certain degree, but the requirement of more realistic system.

Table one simulation parameter

Fig. 8 is prior art and the comparison schematic diagram of the embodiment of the invention on downlink throughput capacity.Wherein, the descending unified MMSE detection algorithm that adopts, emulation obtains totally 5 performance curves at 3 kinds of descending MU-MIMO methods, is respectively that BD, BD+SVD and the method that the present invention is based on QRD (are curve B D-QRD _Eq ⁰, BD-QRD _Eq ¹, BD-QRD _Eq ²), wherein the iterations of SU-BF is set to 0,1,2 respectively.When iterations is 0, mean and do not carry out SU-BF to have only MU-BF.

As can be seen from Figure 8: 1. for MU-BF, performance based on QRD is better than the performance of traditional B D, reason is that MU-BF matrix based on QRD on the diagonalizable basis of piecemeal, further realized the trigonometric ratio of hypermatrix, can reduce the interference between the data flow; 2. for SU-BF, very fast based on the iterative convergence speed of QRD, only 1-2 iteration of need can reach the performance of SVD.

Fig. 9 is prior art and the comparison schematic diagram of the embodiment of the invention on uplink throughput, the up unified associating MMSE detection algorithm that adopts, and emulation obtains totally 7 performance curves at 4 kinds of up MU-MIMO methods.These 4 kinds up MU-MIMO methods are respectively: make a start do not carry out beam forming (NoBF), SVD, the present invention is directed to equivalent channel, to carry out QRD (be curve QRD _Eq ⁰, QRD _Eq ¹, QRD _Eq ²), the present invention is directed to physical channel, to carry out QRD (be curve QRD _Phy ¹, QRD _Phy ²).Wherein, when carrying out QRD, uply only carry out QRD 1 time, and the iterations of descending QRD is set to 0,1,2 respectively at equivalent channel; When carrying out QRD at physical channel, up iterations is set to 1 and 2 respectively.

As can be seen from Figure 9: 1. when the up-downgoing resource allocation is identical, can reach the performance identical based on the QRD of equivalent channel, and ascending performance is littler to the dependence of descending QRD iterations with SVD; 2. when the up-downgoing resource allocation not simultaneously, can carry out the QRD iteration based on physical channel, though performance descends to some extent based on the QRD or the SVD of equivalent channel, and do not carry out beam forming and compare and still have obvious performance gain.

The above only is preferred embodiment of the present invention, and is in order to restriction the present invention, within the spirit and principles in the present invention not all, any modification of being done, is equal to replacement, improvement etc., all should be included within protection scope of the present invention.

Claims (24)

1. the transmission method of multi-user's multiple-input and multiple-output MU-MIMO in the wireless communication system is characterized in that, comprising:

The base station receives the detecting pilot frequency SRS that sends from N user terminal UE and carries out channel estimating, and generates the descending channel information matrix according to the channel reciprocity of channel estimation results and described system, and wherein said N is greater than 1;

The QR decomposition is carried out to the descending channel information matrix of described generation in described base station, obtains the multi-user beam moulding MU-BF matrix P of i UE from the Q matrix that decomposition obtains ⁽ⁱ⁾, and further obtain descending single user wave beam moulding SU-BF matrix V of i UE ⁽ⁱ⁾, i=1 wherein ..., N;

Described base station is according to described MU-BF matrix P ⁽ⁱ⁾With described descending SU-BF matrix V ⁽ⁱ⁾, the emission data of i UE are carried out beam forming handle.

2. method according to claim 1 is characterized in that, further comprises:

Described base station is according to MU-BF matrix and the descending SU-BF matrix of i UE, the special pilot frequency for user of this UE is carried out the launching beam forming processes after, send to described UE.

3. method according to claim 1 is characterized in that, further comprises:

I UE receives the descending pilot frequency that described base station sends and carries out channel estimating, obtains the descending channel information matrix at this UE;

This UE carries out QR to described descending channel information matrix and decomposes, and obtains the uplink single user beam forming SU-BF matrix U of self from the Q matrix that decomposition obtains ⁽ⁱ⁾

According to this up SU-BF matrix the emission data being carried out beam forming handles.

4. method according to claim 3 is characterized in that, described UE carries out QR to the descending channel information matrix and decomposes and to obtain up SU-BF matrix and comprise:

The special pilot frequency for user of i UE reception base station transmission carries out channel estimating, obtains descending equivalent channel matrix;

This UE carries out QR to described descending equivalent channel matrix and decomposes, and the Q matrix that decomposition is obtained is as the first up SU-BF matrix of described UE.

5. method according to claim 3 is characterized in that, described UE carries out QR to the descending channel information matrix and decomposes and to obtain up SU-BF matrix and comprise:

The cell-specific pilot tone of i UE reception base station transmission is carried out channel estimating, obtains the down physical channel matrix, and obtains the uplink physical channel matrix according to channel reciprocity;

This UE carries out QR to described uplink physical channel matrix and decomposes, and the Q matrix that obtains from decomposition obtains the second up SU-BF matrix of described UE.

6. method according to claim 3 is characterized in that, further comprises:

This UE carries out conjugate transpose to up SU-BF matrix;

According to the conjugate transpose of described up SU-BF matrix the reception data of this UE are carried out carrying out MIMO and detecting after beam forming handles.

7. according to each described method of claim 3-6, it is characterized in that, further comprise: this UE is according to described up SU-BF matrix, uplink demodulation pilot tone DMRS is carried out the launching beam forming processes after, send to described base station.

8. method according to claim 1 is characterized in that, further comprises:

Conjugate transpose is carried out to MU-BF matrix and the descending SU-BF matrix of i UE in described base station;

According to the conjugate transpose of the MU-BF matrix of described UE the reception data of this base station are carried out multi-user interference and eliminate MUI, obtain the reception data of i UE, after utilizing the conjugate transpose of descending SU-BF matrix that the reception data of this UE are handled again, carry out MIMO and detect.

9. method according to claim 1 is characterized in that, described base station obtains descending single user wave beam moulding SU-BF matrix V of i UE ⁽ⁱ⁾Comprise:

Described base station is according to the down physical channel matrix H of i UE ⁽ⁱ⁾And MU-BF matrix P ⁽ⁱ⁾Obtain H ⁽ⁱ⁾P ⁽ⁱ⁾, and to H ⁽ⁱ⁾P ⁽ⁱ⁾Carry out QR and decompose, obtain the descending SU-BF matrix V of described UE ⁽ⁱ⁾

10. method according to claim 3 is characterized in that, described UE obtains the uplink single user beam forming SU-BF matrix U of self ⁽ⁱ⁾Comprise:

UE is with the uplink physical channel matrix H _UL ⁽ⁱ⁾Conjugate transpose H with this uplink physical channel matrix _UL ^{(i) H}Multiply each other and obtain H _UL ^{(i) H}H _UL ⁽ⁱ⁾, again with H _UL ^{(i) H}H _UL ⁽ⁱ⁾And U _T-1 ⁽ⁱ⁾Decomposition obtains up SU-BF matrix U through QR after multiplying each other _t ⁽ⁱ⁾

11. a base station that is used for multi-user's multiple-input and multiple-output MU-MIMO transmission is characterized in that, comprising:

Channel estimating unit is used to carry out the uplink channel information that channel estimating obtains an above user terminal UE, and obtains the descending channel information matrix according to channel reciprocity;

The QR resolving cell is used for that described descending channel information matrix is carried out QR and decomposes, and obtains the multi-user beam moulding MU-BF matrix of each UE from the Q matrix that decomposition obtains, and further obtains descending single user wave beam moulding SU-BF matrix of each UE;

The launching beam forming unit is used for MU-BF matrix and descending SU-BF matrix according to each UE, the emission data of corresponding UE are carried out beam forming handle, and the antenna of delivering to this base station transmits.

12. base station according to claim 11 is characterized in that, the R matrix that described QR resolving cell is further used for decomposition is obtained offers the MIMO detecting unit;

Described MIMO detecting unit is used for according to described R matrix the reception data of antenna being carried out MIMO and detects, and recovers the transmission data of each UE.

13. base station according to claim 12 is characterized in that, described QR resolving cell is further used for the MU-BF matrix of each UE and descending SU-BF matrix are carried out conjugate transpose, offers the received beam forming unit;

Described received beam forming unit, be used for the reception data of described antenna being carried out multi-user interference and eliminate MUI according to the conjugate transpose of the MU-BF matrix of each UE, obtain the reception data of each UE, after utilizing the conjugate transpose of descending SU-BF matrix that the reception data of corresponding UE are handled again, send to described MIMO detecting unit.

14., it is characterized in that described QR resolving cell is further used for the R matrix that obtains according to decomposition according to each described base station of claim 11-13, the data streams of a described above UE carried out Adaptive Modulation and Coding AMC control.

15., it is characterized in that described QR resolving cell is used for the down physical channel matrix H according to each UE according to each described base station of claim 11-13 ⁽ⁱ⁾And MU-BF matrix P ⁽ⁱ⁾Obtain H ⁽ⁱ⁾P ⁽ⁱ⁾, and to H ⁽ⁱ⁾P ⁽ⁱ⁾Carry out QR and decompose, obtain the descending SU-BF matrix V of each UE ⁽ⁱ⁾, described i is from 1 arbitrary integer to number of users N.

16. according to each described base station of claim 11-13, it is characterized in that, described channel estimating unit is used for carrying out channel estimating according to the detecting pilot frequency SRS that each UE sends, perhaps the uplink demodulation pilot tone DMRS that sends according to each UE obtains uplink channel information, and obtains the descending channel information matrix according to channel reciprocity.

17., it is characterized in that described launching beam forming unit is further used for according to the MU-BF matrix of each UE and descending SU-BF matrix according to each described base station of claim 11-13, the special pilot frequency for user of issuing each UE carried out beam forming handle.

18. a user terminal UE who is used for multi-user's multiple-input and multiple-output MU-MIMO transmission is characterized in that, comprising:

Channel estimating unit is used to carry out channel estimating, obtains the descending channel information matrix of this UE;

The QR resolving cell is used for that described descending channel information matrix is carried out QR and decomposes, and obtains the uplink single user beam forming SU-BF matrix of this UE from the Q matrix that decomposition obtains;

The launching beam forming unit is used for according to the up SU-BF matrix of this UE the emission data being carried out the beam forming processing, and sends from the antenna of this UE.

19. UE according to claim 18 is characterized in that, described channel estimating unit is used for carrying out channel estimating according to the special pilot frequency for user that the base station sends, and obtains descending equivalent channel matrix;

Described QR resolving cell is used for that described descending equivalent channel matrix is carried out QR and decomposes, and the Q matrix that decomposition is obtained is as the first up SU-BF matrix of this UE.

20. UE according to claim 18 is characterized in that, described channel estimating unit is used for carrying out channel estimating according to the cell-specific pilot tone that the base station sends, and obtains the down physical channel matrix, and obtains the uplink physical channel matrix according to channel reciprocity;

Described QR resolving cell is used for that described uplink physical channel matrix is carried out QR and decomposes, and the Q matrix that obtains from decomposition obtains the second up SU-BF matrix of this UE.

21., it is characterized in that the R matrix that described QR resolving cell is further used for decomposition is obtained offers the MIMO detecting unit according to each described UE of claim 18-20;

Described MIMO detecting unit is used for according to described R matrix the reception data of this UE being carried out MIMO and detects.

22. UE according to claim 21 is characterized in that, described QR resolving cell is further used for the up SU-BF matrix of this UE is carried out conjugate transpose, offers the received beam forming unit;

Described received beam forming unit after being used for according to the conjugate transpose of described up SU-BF matrix the reception data of this UE being handled, sends to described MIMO detecting unit.

23., it is characterized in that described QR resolving cell is further used for the R matrix that obtains according to decomposition according to each described UE of claim 18-20, the above data streams of described UE carried out Adaptive Modulation and Coding AMC control.

24., it is characterized in that described launching beam forming unit is further used for the up SU-BF matrix according to this UE according to each described UE of claim 18-20, uplink demodulation pilot tone DMRS carried out beam forming handle.

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