CN101350655B - Method for eliminating interference between users - Google Patents
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- CN101350655B CN101350655B CN 200710137288 CN200710137288A CN101350655B CN 101350655 B CN101350655 B CN 101350655B CN 200710137288 CN200710137288 CN 200710137288 CN 200710137288 A CN200710137288 A CN 200710137288A CN 101350655 B CN101350655 B CN 101350655B
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Abstract
The present invention discloses a method of eliminating the interference between users, and comprises the following steps: S102: adopting the matrix consisting of one or more than one column vectors in the channel information matrix from each user for the weighting processing of transmission signals; and S104: completing the weighting processing of the transmission signals at the reception end after the weighting processing, so as to separate the transmission signals after weighting processing and to further eliminate the interference between the users. The method adopts the appropriate weighting vector of transmitting antennas and receiving antennas to separate the signals of a plurality of users, so as to eliminate the interference.
Description
Technical field
The present invention relates to the MIMO wireless moving communicating field, relate more specifically to a kind of method of eliminating inter-user interference.
Background technology
Multiple-input and multiple-output (Multiple Input and Multiple Output, being called for short MIMO) system becomes in the Long Term Evolution research of (Long TermEvolution is called for short LTE) the extremely technology paid close attention to of people owing to can effectively improving channel capacity.
For multiuser MIMO (Multi-User MIMO is called for short MU-MIMO) system, the key problem of being concerned about is to utilize spatial information that the user area is separated, and makes a plurality of users can use simultaneously the resources such as identical frequency and time.Only distinguish the user by spatial information, eliminate the interference between the user.
The performance constraints condition of existing interference elimination method is as follows:
(1.BD Block Diagonalize) method
The prerequisite that the BD algorithm is eliminated inter-user interference fully is N
RX* (K-1)≤N
TX, wherein, N
RXBe the reception antenna number of subscriber equipment (User Equipment is called for short UE) end, K is the subscriber equipment number, N
TXNumber of transmit antennas for Node B (Node B) end.
2. matrix inversion technique
The matrix inversion algorithm is eliminated inter-user interference fully, and also eliminating the prerequisite of disturbing between stream simultaneously is N
RX* K≤N
TX, while N
S≤ N
RX, wherein, N
RXBe the reception antenna number of UE end, N
SBe grade (rank) number that each user uses, K is user's number, N
TXNumber of transmit antennas for Node B end.
3.ZF (zero-forcing) method
The ZF algorithm is eliminated inter-user interference fully, and also eliminating the prerequisite of disturbing between stream simultaneously is N
RX* K≤N
TX, while N
S≤ N
RX, wherein, N
RXBe the reception antenna number of UE end, N
SBe the rank number that each user uses, K is user's number, N
TXNumber of transmit antennas for Node B end.
Existing this several method all needs to feed back whole channel matrix or the matrix relevant to channel information, and feedback overhead is larger.
Summary of the invention
One or more problems in view of the above the invention provides a kind of method of eliminating inter-user interference.
In the multiuser MIMO pattern, can come by the weighted vector that designs suitable transmitting antenna and reception antenna separately multi-user's signal, remove and disturb.In order to reduce feedback overhead, the present invention proposes a kind of ZF (Zero forcing the is called for short ZF) method that can only feed back a vector, be called for short Vector ZF method.
In Vector ZF method, for the MU-MIMO system that has K user, channel matrix is respectively H
1..., H
K, be computing [U for each user
j, D
j, V
j]=svd (H
j).Make UH
j=(U
j H* H
j)
T, UH
jBe equivalent to (D
j* V
j H)
T, D
jThe characteristic value of descending arrangement, V
jIt is the efficient precoding weighted vector.In order to reduce feedback overhead, do not carry out whole UH
jThe feedback of matrix, each user only feeds back UH
jThe front N of matrix
SIndividual column vector, wherein, N
SBe the rank number that each user uses, H
MU=[UH
1(:, 1:N
S) ... UH
j(:, 1:N
S) ... UH
K(:, 1:N
S)
T, weighted vector is W=pinv (H
MU), U
jPrecoding weights as j user's receiving terminal use.
Wherein, the Vector ZF method according to the present invention prerequisite of eliminating inter-user interference fully is N
S* K≤N
TX, wherein, N
SBe the rank number that each user uses, K is user's number, N
TXNumber of transmit antennas for the Node B end.
Wherein, Vector ZF method according to the present invention is eliminated inter-user interference fully simultaneously also to eliminate the prerequisite of disturbing between stream is N
RX* K≤N
TX, while N
S≤ N
RX, wherein, N
RXBe the reception antenna number of UE end, N
SBe the rank number that each user uses, K is user's number, N
TXNumber of transmit antennas for the Node B end.
In sum, can come by the weighted vector that designs suitable transmitting antenna and reception antenna separately multi-user's signal, remove and disturb.The present invention can only feed back a column vector, and the prerequisite that elimination is disturbed is N
S* K≤N
TX, more loose to the requirement of hardware.
Description of drawings
Accompanying drawing described herein is used to provide a further understanding of the present invention, consists of the application's a part, and illustrative examples of the present invention and explanation thereof are used for explaining the present invention, do not consist of improper restriction of the present invention.In the accompanying drawings:
Fig. 1 is the flow chart of the method for elimination inter-user interference according to an embodiment of the invention;
Fig. 2 be elimination inter-user interference according to another embodiment of the invention method the process schematic diagram; And
Fig. 3 is that simulated conditions is the simulation result schematic diagram of the situation of 4*4 antenna configuration, 2 users, ideal feedback information.
Embodiment
Below with reference to accompanying drawing, describe the specific embodiment of the present invention in detail.
With reference to figure 1, the method for elimination inter-user interference according to an embodiment of the invention is described.As shown in Figure 1, the method of this elimination inter-user interference comprises the following steps: S102, utilize the matrix that wherein one or more column vectors of the channel information matrix that each user in a plurality of users feeds back respectively form respectively a plurality of transmitting to be weighted processing; And S104, the weightings of carrying out receiving terminal that transmit that weighting is processed to a plurality of process are processed, and are a plurality of through transmitting that weighting is processed to separate, and then the interference between the elimination user.
Wherein, in step S104, by a plurality of of each user that are transmitted in a plurality of users are carried out following computing through transmitting of weighting processing, separate a plurality of through transmitting that weighting is processed: [U
j, D
j, V
j]=svd (H
j), wherein, UH
j=(U
j H* H
j)
T=(D
j* V
j H)
T, D
jThe characteristic value of descending arrangement, V
jIt is the efficient precoding weighted vector.
Wherein, wherein one or more column vectors of the channel information matrix of each user feedback in a plurality of users are UH
jThe front N of matrix
SIndividual column vector, wherein, N
SIt is the number of levels that each user in a plurality of users uses.Front N
SThe matrix that individual column vector forms is H
MU=[UH
1(:, 1:N
S) ... UH
j(:, 1:N
S) ... UH
K(:, 1:N
S)]
TBy front N
SBeing used for that the matrix that individual column vector forms draws is W=pinv (H to a plurality of weighted vectors that are weighted processing that transmit
MU), wherein, U
jBe j user's precoding weights.
Wherein, the prerequisite of eliminating inter-user interference fully according to the method for elimination inter-user interference of the present invention is N
S* K≤N
TX, wherein, N
SBe the number of levels that each user uses, K is user's number, N
TXNumber of transmit antennas for the Node B end.
Wherein, eliminating inter-user interference fully according to the method for elimination inter-user interference of the present invention, simultaneously also to eliminate the prerequisite of disturbing between stream be N
RX* K≤N
TX, while N
S≤ N
RX, wherein, N
RXBe the reception antenna number of user side, N
SBe the number of levels that each user uses, K is user's number, N
TXNumber of transmit antennas for the Node B end.
With reference to figure 2, the method for elimination inter-user interference according to another embodiment of the invention is described.In the embodiment shown in Figure 2, suppose that each user uses 1 data flow, i.e. N
SBe that 1, rank number is also 1; Number of users K is 2, namely uses simultaneously 2 users.Wherein, in order to reduce feedback overhead as far as possible, each user only uses the rank1 mode, so just only needs to feed back a N
TX* the column vector of 1 dimension, feed back the code book that uses and be 4bit (16) column vector code book.The method of elimination inter-user interference as shown in Figure 2 comprises the following steps: each user is computing [U
j, D
j, V
j]=svd (H
j), wherein, UH
j=(U
j H* H
j)
TDo not carry out whole UH
jThe feedback of matrix, each user only feeds back UH
jFirst column vector of matrix; Utilize code book to UH
jFirst column vector of matrix is fed back; Make H
MU=[UH
1(:, 1) ... UH
j(:, 1) ... UH
K(:, 1)]
T, make W=pinv (H
MU), wherein, W is the transmitting terminal weighted vector; U
jPrecoding weights as j user's receiving terminal use.
With reference to figure 3, effect of the present invention is described.The simulated conditions of simulation result shown in Figure 3 is as shown in the table:
| System bandwidth | 10MHz |
| Sub-carrier number | 601 |
| Subcarrier spacing | 15kHz |
| The Resource Block bandwidth | 180kHz (12 subcarrier) |
| Transmission Time Interval (TTI) | (1.0msec 14OFDM symbol) |
| Modulation system | QPSK |
| Code rate | R＝1/3 |
| Chnnel coding/decoding | Turbo coding (K=4)/Max-Log-MAP decoding |
| The Codeword mode | Many code streams (MCW) |
| Antenna number | 4*4MIMO |
| Channel model | SCME |
| Maximum doppler frequency | f D＝5.55Hz(v＝3km/h) |
| Channel estimating | LS |
| Input | MMSE-SIC |
| The pre-coding matrix update cycle | 1TTI(＝1msec) |
| HARQ | None |
Under above-mentioned simulated conditions, the performance of multi-user simulation has some randomnesss, and it depends on two aspects: the degree of correlation of each channel between the user; And performance can be than the time difference a little less than correlation when between the user, channel relevancy is strong.Can find out from simulation result, for the 4*4 antenna configuration, 2 users' situation error performance is good.
In sum, can come by the weighted vector that designs suitable transmitting antenna and reception antenna separately multi-user's signal, remove and disturb.
The above is only embodiments of the invention, is not limited to the present invention, and for a person skilled in the art, the present invention can have various modifications and variations.Within the spirit and principles in the present invention all, any modification of doing, be equal to replacement, improvement etc., within all should being included in claim scope of the present invention.
Claims (3)
1. a method of eliminating inter-user interference, is characterized in that, comprises the following steps:
S102 utilizes the matrix that wherein one or more column vectors of the channel information matrix that each user in a plurality of users feeds back respectively form respectively a plurality of transmitting to be weighted processing; And
S104 processes a plurality of weightings of carrying out receiving terminal that transmit of processing through weighting, and is described a plurality of through transmitting that weighting is processed to separate, and then eliminates the interference between the user;
Wherein, in described step S104, by the described a plurality of of each user that are transmitted in described a plurality of user are carried out following computing through transmitting of weighting processing, separate described a plurality of through transmitting that weighting is processed: [U
j, D
j, V
j]=svd (H
j), wherein, UH
j=(U
j H* H
j)
T=(D
j* V
j H)
T, D
jThe characteristic value of descending arrangement, V
jThe efficient precoding weighted vector, U
jBe j user's precoding weights;
Wherein one or more column vectors of the channel information matrix of each user feedback in described a plurality of user are UH
jThe front N of matrix
SIndividual column vector, wherein, N
SIt is the number of levels that each user in described a plurality of user uses;
Described front N
SThe matrix that individual column vector forms is H
MU=[UH
1(:, 1:N
S) ... UH
j(:, 1:N
S) ... UH
K(:, 1:N
S)]
T
By described front N
SBeing used for that the matrix that individual column vector forms draws is W=pinv (H to described a plurality of weighted vectors that are weighted processing that transmit
MU).
2. the method for elimination inter-user interference according to claim 1, is characterized in that, the prerequisite that described method is eliminated inter-user interference fully is N
S* K≤N
TX, wherein, N
SBe the number of levels that each user uses, K is user's number, N
TXNumber of transmit antennas for the Node B end.
3. the method for elimination inter-user interference according to claim 1, is characterized in that, described method is eliminated inter-user interference fully, and simultaneously also to eliminate the prerequisite of disturbing between stream be N
RX* K≤N
TX, while N
S≤ N
RX, wherein, N
RXBe the reception antenna number of user side, N
SBe the number of levels that each user uses, K is user's number, N
TXNumber of transmit antennas for the Node B end.
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|---|---|---|---|
| CN 200710137288 CN101350655B (en) | 2007-07-18 | 2007-07-18 | Method for eliminating interference between users |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 200710137288 CN101350655B (en) | 2007-07-18 | 2007-07-18 | Method for eliminating interference between users |
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|---|---|
| CN101350655A CN101350655A (en) | 2009-01-21 |
| CN101350655B true CN101350655B (en) | 2013-06-12 |
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| CN 200710137288 Expired - Fee Related CN101350655B (en) | 2007-07-18 | 2007-07-18 | Method for eliminating interference between users |
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Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1710899A (en) * | 2005-05-27 | 2005-12-21 | 西安电子科技大学 | Interactive parameter estimation method of multi-input and multi-output system |
| CN1905400A (en) * | 2005-07-27 | 2007-01-31 | 松下电器产业株式会社 | Space multiplex system and method for non-independent multi-input/output channel |
-
2007
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Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1710899A (en) * | 2005-05-27 | 2005-12-21 | 西安电子科技大学 | Interactive parameter estimation method of multi-input and multi-output system |
| CN1905400A (en) * | 2005-07-27 | 2007-01-31 | 松下电器产业株式会社 | Space multiplex system and method for non-independent multi-input/output channel |
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| Publication number | Publication date |
|---|---|
| CN101350655A (en) | 2009-01-21 |
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