WO2013135021A1

WO2013135021A1 - Method and device for data transmission on basis of channel state information feedback

Info

Publication number: WO2013135021A1
Application number: PCT/CN2012/077753
Authority: WO
Inventors: 关艳峰; 陈宪明; 鲁照华
Original assignee: 中兴通讯股份有限公司
Priority date: 2012-03-13
Filing date: 2012-06-28
Publication date: 2013-09-19
Also published as: CN103312440A

Abstract

Disclosed in the present invention is a method for data transmission based on channel state information feedback, comprising: a transmitting terminal obtains the current channel state information of the receiving terminal; said transmitting terminal corrects said current channel state information on the basis of past channel state information and obtains corrected channel state information; said transmitting terminal determines, on the basis of the corrected channel state information, control information used at the time of data transmission to said receiving terminal, and transmits data to said receiving terminal on the basis of said control information. The present invention also discloses a device for data transmission based on channel state information feedback. The present invention, by means of correcting channel state information fed back by an opposing terminal, improves the accuracy of channel state information, raises the accuracy of the MIMO transmission scheme and precoding and enhances data transmission performance.

Description

Data transmission method and device based on channel state information feedback

The present invention relates to the field of communications, and in particular, to a data transmission method and apparatus based on channel state information feedback. Background technique

With the rapid development of wireless communication technology, severely insufficient spectrum resources have become the main factor restricting the development of wireless communication. How to make full use of limited spectrum resources and improve spectrum utilization is an important research direction of wireless communication. Multiple Input Multiple Output (MIMO) technology is widely used because it can improve transmission efficiency and spectrum utilization without increasing bandwidth. MIMO technology utilizes spatial diversity gain through transmit diversity and receive diversity, antenna array gain through beamforming techniques, and spatial multiplexing gain through spatial multiplexing techniques. The obtaining spatial diversity gain utilizes the weak correlation of the spatial channel, and combined with the selectivity in time/frequency, the transmit diversity provides multiple signal copies for signal transmission, and the receive diversity is to receive multiple signals transmitted by the transmitted signal in space. Copy, thereby improving the reliability of signal transmission, thereby improving the signal-to-noise ratio of the received signal - such as Space Frequency Block Code; obtaining the strong correlation of the antenna array gain using the spatial channel, by installing a small-pitch antenna array, The electromagnetic waves transmitted in the space are interfered to form a strong directional radiation pattern, so that the main lobe of the radiation pattern is adaptively directed to the user's incoming wave direction, thereby improving the signal-to-noise ratio of the received signal and improving the system capacity or coverage range - For example, single stream beamforming (Single Stream Beamforming); obtaining spatial multiplexing gain is to use the weak correlation of spatial channels to transmit different data streams on multiple independent spatial channels, thereby increasing the peak rate of data transmission - for example, User Multiple Input Multiple Output (MU-MIMO, Mutiple User MI MO) technology. Obviously, the use of MIMO technology is heavily dependent on the characteristics of the spatial channel and its measurements. In the Long Term Evolution Release (LTE Release) 8/9, in order to measure the spatial channel state or quality and demodulate the received data symbols, a common reference signal (CRS, Common Reference Signal;) is introduced. The user equipment (UE, User Equipment) can perform channel state measurement through the CRS, and provide basic channel state information for selecting different MIMO transmission modes for the user equipment and the cell, and is implemented by CRS in LTE Release 8/9. The measurement of the channel by the terminal also realizes the demodulation of the data transmitted by the terminal to the cell; the supported transmission modes include diversity, open-loop single-user MIMO (SU-MIMO, Single User MIMO), beamforming, closed-loop single-user ΜΙΜΟ Closed loop MU-MIMO.

In LTE Release 10, a new Channel State Information-Reference Signal (CSI-RS) is defined for channel measurement. The UE may perform measurement through the CSI-RS and calculate a Precoding Matrix Indicator (PMI), a Channel Quality Indicator (CQI, Channel Quality Indicator), and a Rank Indicator (RI, Rank Indicator), which are fed back to the base station. CSI-RS provides the possibility to further improve the spectrum utilization of the cell, especially the spectrum utilization of the cell edge, because CSI-RS provides the possibility of Cooperative Multi-Point (CoMP) technology, and CoMP technology enables MIMO technology. It is no longer limited to a single cell, but can be combined and coordinated by multiple cells. Downstream CoMP technology mainly includes two forms:

Coordinated Scheduling/Coordinated Beamforming (CS/CB): Data is transmitted only from the serving cell, but the UE scheduling or BF mode is jointly performed by the coordination point.

Joint Transmission (JT): Data is jointly processed by each collaboration point, that is, each UE's data is jointly transmitted by all the cooperation points to improve reception quality and eliminate interference. Two typical diagrams of JT are shown in Figures 1 and 2, which consist of multiple senders and one or more receivers.

At present, the implementation of MIMO technology relies on feedback from the UE on channel state information. Or the cooperative end determines the transmission mode of the MIMO according to the channel state information that is fed back. Because the capacity of the feedback channel is limited, the feedback is limited feedback, that is, only limited channel state information can be fed back, and the limited channel state information is also quantized, and there is distortion. The problem, and the accuracy of the channel state information severely restricts the gain brought by MIMO technology. E.g:

For example, the typical implementation algorithm of CS/CB technology is based on Signal to Leakage and Noise Ratio (SLNR). The SLNR-based CB technology requires a channel between neighboring terminals to the cell of the scheduled terminal (Cell). Coefficient, in the actual system, due to limited feedback, at most the precoding matrix index between the neighboring terminals and the serving base station of the scheduled terminal is obtained, and the real channel coefficient matrix cannot be obtained, which seriously affects the effect of the SLNR-based CB technology. As shown in Fig. 1, the service transmitting end of the receiving end 1 is the transmitting end 1, and the transmitting end 1 determines the precoding vector that is desired to be used when transmitting data to the receiving end 1 based on the formula (1) when using the CB of the SLNR: argmax

Where „ is the matrix of channel coefficients between the transmitting end 1 and the receiving end η, W is the precoding matrix, and σ ² is the noise power. Obviously, the optimal precoding vector under the SLNR criterion is

(H Hu +

The maximum eigenvalue corresponding to the largest eigenvalue, but the receiving ends 1 and 2 can only feed back the optimal PMI, and can not directly feed back the channel coefficient matrix „. Existing SLNR-based CB techniques are directly through the codeword corresponding to the PMI Instead of the channel coefficient matrix H _LN , the optimal precoding vector is determined, namely:

There is a deviation between the formula (1) and the optimal solution of the formula (2). Taking the rank(H _ln )=l as an example, the specific analysis is as follows:

According to the spectral decomposition of the matrix:

(3)

Where v _l is the eigenvector corresponding to the maximum eigenvalue of H^H _{L. In} this example, n takes 1 and 2, obviously, 1, when ≠1, replace the complete codeword W corresponding to the limited channel information PMI. The channel information Η is feasible, and the code word W is quantized.

For example, for MU-MIMO, whether it is a single base station MU-MIMO or a multi-base station MU-MIMO (MU-MIMO-JT), MU precoding is required for the paired UE, and a single base station MU-MIMO is taken as an example:

For the channel coefficient matrix between UE1 and the base station, ₂ is the channel coefficient matrix between UE2 and the base station, and the joint channel is [H ₂ ^T , and the multi-user precoding based on the zero-forcing criterion is:

P=H ^H (HH ( 4 )

Since the actual system cannot obtain the complete channel state information, H is generally replaced by a vector corresponding to the precoded vector index fed back by the terminal.

It can be seen that in the prior art, only part of the channel state information is obtained by the transmitting end, and part of the channel state information is generally affected by quantization and delay, and there is a problem of distortion, especially in a slowly varying MIMO channel, and the MIMO system often adopts a closed loop mode, that is, The terminal feeds back a partial channel state signal channel measurement reference signal to the base station, and the base station determines the precoding used when transmitting data to the terminal by using the reciprocity of the uplink and downlink channel state information, and the problem of channel state information distortion is difficult to avoid, thereby further affecting Data transfer performance. Summary of the invention

In view of this, the main purpose of the embodiments of the present invention is to provide a data transmission method based on channel state information feedback, which can solve the problem of channel state information distortion and poor data transmission performance existing in the prior art.

To achieve the above objective, the technical solution of the embodiment of the present invention is implemented as follows:

A data transmission method based on channel state information feedback includes:

The transmitting end acquires current channel state information fed back by the receiving end;

Transmitting, by the transmitting end, the current channel state information according to the historical channel state information, to obtain corrected channel state information;

The transmitting end determines control information used when transmitting data to the receiving end according to the modified channel state information, and transmits data to the receiving end according to the control information.

The current channel state information includes one or more of the following: a right singular vector of a current channel coefficient matrix, a current channel coefficient correlation matrix, a modulation coding mode of a current channel, and a rank of a current channel coefficient matrix;

The historical channel state information includes one or more of the following: a right singular vector of a historical channel coefficient matrix, a historical channel coefficient correlation matrix, a modulation coding mode of a historical channel, and a rank of a historical channel coefficient matrix;

The modified channel state information includes one or more of the following: a right singular vector of the modified channel coefficient matrix, a modified channel coefficient correlation matrix, a modulation coding mode of the modified channel, and a rank of the modified channel coefficient matrix.

The transmitting end corrects the current channel state information according to the historical channel state information, and obtains the corrected channel state information as:

Correcting a right singular vector of the current channel coefficient matrix according to a right singular vector or a historical channel coefficient correlation matrix of the historical channel coefficient matrix to obtain a right singular vector of the modified channel coefficient matrix; or Correcting the current channel coefficient correlation matrix according to the historical channel coefficient correlation matrix to obtain a modified channel coefficient correlation matrix; or

Correcting the modulation and coding mode of the current channel according to the modulation and coding mode of the historical channel, and obtaining a modulation and coding mode of the modified channel; or

The rank of the current channel coefficient matrix is corrected according to the rank of the historical channel coefficient matrix, and the rank of the modified channel coefficient matrix is obtained.

Correcting the right singular vector of the current channel coefficient matrix according to the right singular vector of the historical channel coefficient matrix, and obtaining the right singular vector of the modified channel coefficient matrix is:

Correct the right singular vector of the channel coefficient matrix = a x the right singular vector of the current channel coefficient matrix + (l-a) x the right singular vector of the historical channel coefficient matrix, where 0 < a <= l ,

The correcting the current channel coefficient correlation matrix according to the historical channel coefficient correlation matrix, and obtaining the modified channel coefficient correlation matrix is:

Corrected channel coefficient correlation matrix = b x current channel coefficient correlation matrix + (l-b) x historical channel coefficient correlation matrix, where 0 < b <= l.

The correcting the right singular vector of the current channel coefficient matrix according to the historical channel coefficient correlation matrix, and obtaining the right singular vector of the modified channel coefficient matrix is:

SVD decomposition is performed on the correlation coefficient R of the historical channel coefficient: R=V∑;

Calculate the right singular vector of the modified channel coefficient matrix according to the following formula:

Correct the right singular vector of the channel coefficient matrix = cx the right singular vector of the current channel coefficient matrix + (lc) X Colum(y, dim), where 0<C<=1, Colum(y, dim) is the matrix V The front dim column, dim is the number of columns of the right singular vector of the current channel coefficient matrix.

The modulation coding mode of the current channel is corrected according to the modulation and coding mode of the historical channel, and the modulation and coding mode of the modified channel is obtained as follows:

First, calculate the value of (dx modulation coding mode of the current channel + (1 -d) X modulation channel coding mode of the history channel), and then perform rounding operation on the calculated value to obtain the modulation coding side of the modified channel. Where, 0 < d <= l ;

And correcting the rank of the current channel coefficient matrix according to the rank of the historical channel coefficient matrix, and obtaining the rank of the modified channel coefficient matrix:

First calculating (ex the rank of the current channel coefficient matrix + (le) the rank of the X historical channel coefficient matrix), and then performing a rounding operation on the calculated value to obtain the rank of the modified channel coefficient matrix, where 0 < e <=l.

The control information includes one or more of the following: a precoding vector, a stream number, and a modulation and coding method used when the transmitting end sends data to the receiving end, and determining a precoding vector according to a right singular vector of the modified channel coefficient matrix, according to the modified channel. The modulation coding method determines the modulation coding mode, and determines the number of streams according to the rank of the modified channel coefficient matrix.

A data transmitting apparatus based on channel state information feedback, comprising: a current channel state information acquiring module, a channel state information correcting module, a control information determining module, and a data transmitting module; wherein

The current channel state information acquiring module is configured to acquire current channel state information fed back by the receiving end;

The channel state information correction module is configured to correct current channel state information acquired by the current channel state information acquiring module according to the historical channel state information, to obtain corrected channel state information;

The control information determining module is configured to determine, according to the modified channel state information obtained by the channel state information correction module, control information used when transmitting data to the receiving end;

The data transmitting module is configured to transmit data to the receiving end according to the control information determined by the control information determining module.

The channel state information correction module is specifically configured to correct a right singular vector of the current channel coefficient matrix according to a right singular vector of the historical channel coefficient matrix to obtain a right singular vector of the modified channel coefficient matrix, where the correct channel coefficient matrix is right Singular vector = ax current channel system The right singular vector of the number matrix + ( la) The right singular vector of the X historical channel coefficient matrix, where 0 < a <= l.

The channel state information correction module is specifically configured to correct the current channel coefficient correlation matrix according to the historical channel coefficient correlation matrix to obtain a modified channel coefficient correlation matrix, the modified channel coefficient correlation matrix=b X current channel coefficient correlation matrix+( l -b) X history channel coefficient correlation matrix, where 0 < b <= l.

The channel state information correction module is specifically configured to correct the right singular vector of the current channel coefficient matrix according to the historical channel coefficient correlation matrix to obtain a right singular vector of the modified channel coefficient matrix, specifically, the historical channel coefficient correlation matrix R is SVD decomposition: R = V ∑ V ^H ; Then, calculate the right singular vector of the modified channel coefficient matrix = c X the right singular vector of the current channel coefficient matrix + (lc) X Colum (y, dim) , where 0 < C < =1, Colum( , dim) is the pre-dim column of the matrix V, and dim is the number of columns of the right singular vector of the current channel coefficient matrix.

The channel state information correction module is specifically configured to modify the modulation and coding mode of the current channel according to the modulation and coding mode of the historical channel, to obtain a modulation and coding mode of the modified channel, and specifically, first calculate (dx the modulation coding mode of the current channel + (l -d) The value of the modulation coding mode of the X history channel, and then performing a rounding operation on the calculated value to obtain a modulation coding mode of the modified channel, where 0 < d <= l.

The channel state information correction module is specifically configured to correct the rank of the current channel coefficient matrix according to the rank of the historical channel coefficient matrix, to obtain the rank of the modified channel coefficient matrix, specifically, first calculating (e x the rank of the current channel coefficient matrix) +( le) the value of the rank of the historical channel coefficient matrix, and then rounding the calculated value to obtain the rank of the modified channel coefficient matrix, where

0<e<= l.

In the embodiment of the present invention, the data transmission method and device based on channel state information feedback, the transmitting end acquires current channel state information fed back by the receiving end; and the transmitting end corrects the current channel state information according to the historical channel state information to obtain a modified channel. Status information; the transmitting end Determining control information used when transmitting data to the receiving end according to the modified channel state information, and transmitting data to the receiving end according to the control information. The embodiment of the invention improves the channel state information by modifying the channel state information fed back by the peer end, thereby improving the accuracy of the channel state information.

The accuracy of the MIMO transmission mode and the accuracy of precoding improve the data transmission performance. DRAWINGS

1 is a schematic diagram of a situation of joint transmission in the prior art;

2 is a schematic diagram of another situation of joint transmission in the prior art;

3 is a schematic flowchart of a data transmission method based on channel state information feedback according to an embodiment of the present invention;

4 is a schematic structural diagram of a data transmitting apparatus based on channel state information feedback according to an embodiment of the present invention;

FIG. 5 is a schematic diagram of channel state information modification in Embodiment 1 of the present invention; FIG.

FIG. 6 is a schematic diagram of channel state information modification in a single base station scenario according to Embodiment 2 of the present invention; FIG. 7 is a schematic diagram of channel state information correction in a CB scenario according to Embodiment 3 of the present invention; FIG. 8 is a single base station MU in Embodiment 4 of the present invention; Schematic diagram of channel state information modification in a MIMO scenario;

FIG. 9 is a schematic diagram of channel state information modification of a SU-MIMO JT scenario in Embodiment 5 of the present invention. detailed description

The basic idea of the embodiment of the present invention is: the transmitting end acquires current channel state information fed back by the receiving end; the transmitting end corrects the current channel state information according to the historical channel state information, to obtain corrected channel state information; Determining, according to the modified channel state information, control information used when transmitting data to the receiving end, and transmitting data to the receiving end according to the control information FIG. 3 is a schematic flowchart of a data transmission method based on channel state information feedback according to an embodiment of the present invention. As shown in FIG. 3, the method includes:

Step 301: The transmitting end acquires current channel state information fed back by the receiving end.

It should be noted that the current channel state information may include one or more of the following: a right singular vector of the current channel coefficient matrix, a current channel coefficient correlation matrix, a modulation coding mode of the current channel, and a rank of the current channel coefficient matrix.

Step 302: The transmitting end corrects the current channel state information according to the historical channel state information to obtain corrected channel state information.

Here, the historical channel state information refers to channel state information fed back by the receiving end before the current channel state information is fed back, and may include one or more of the following: a right singular vector of a historical channel coefficient matrix, a historical channel coefficient correlation matrix, and a modulation of a historical channel. The coding mode and the rank of the historical channel coefficient matrix, correspondingly, the modified channel state information may include one or more of the following: a modified right singular vector of the channel coefficient matrix, a modified channel coefficient correlation matrix, a modified channel modulation coding mode, and a modified channel The rank of the coefficient matrix.

It should be noted that, the transmitting end corrects the current channel state information according to the historical channel state information, and the obtained channel state information may be:

Correcting the right singular vector of the current channel coefficient matrix according to the right singular vector or the historical channel coefficient correlation matrix of the historical channel coefficient matrix, and obtaining the right singular vector of the modified channel coefficient matrix; or

Correcting the current channel coefficient correlation matrix according to the historical channel coefficient correlation matrix to obtain a modified channel coefficient correlation matrix; or

The rank of the current channel coefficient matrix is corrected according to the rank of the historical channel coefficient matrix, and the rank of the modified channel coefficient matrix is obtained. Optionally, the right singular vector of the current channel coefficient matrix is corrected according to the right singular vector of the historical channel coefficient matrix, and the right singular vector of the modified channel coefficient matrix is obtained as:

Optionally, the current channel coefficient correlation matrix is corrected according to the historical channel coefficient correlation matrix, and the modified channel coefficient correlation matrix is obtained as follows:

Corrected channel coefficient correlation matrix = b x current channel coefficient correlation matrix +( l -b) x historical channel coefficient correlation matrix, where 0<b<= l.

Optionally, the right singular vector of the current channel coefficient matrix is corrected according to the historical channel coefficient correlation matrix, and the right singular vector of the modified channel coefficient matrix is obtained as:

Correct the right singular vector of the channel coefficient matrix = cx the right singular vector of the current channel coefficient matrix + (lc) Colum(y, dim), where 0<C<=1, Colum(y, dim) is the front of the matrix V The dim column, dim is the column sequence of the right singular vector of the current channel coefficient matrix.

Optionally, the modulation and coding mode of the current channel is modified according to a modulation and coding mode of the historical channel, and the modulation and coding mode of the modified channel is:

First, calculate (dx the modulation coding mode of the current channel + ( l -d) X the modulation coding mode of the X history channel), and then perform a rounding operation on the calculated value to obtain a modulation coding mode of the modified channel, where, 0 <d<= l ;

Optionally, the rank of the current channel coefficient matrix is corrected according to the rank of the historical channel coefficient matrix, and the rank of the modified channel coefficient matrix is obtained as follows:

First calculating (ex the rank of the current channel coefficient matrix + (le) the rank of the X historical channel coefficient matrix), and then performing a rounding operation on the calculated value to obtain the rank of the modified channel coefficient matrix, where 0 < e <=l. Step 303: The transmitting end determines, according to the modified channel state information, control information used when transmitting data to the receiving end, and transmits data to the receiving end according to the control information.

The control information generally includes one or more of the following: a precoding vector, a stream number, a modulation and coding method used when the transmitting end sends data to the receiving end,

Determining, by the transmitting end, the control information used when transmitting data to the receiving end according to the modified channel state information is: determining a precoding vector according to a right singular vector of the modified channel coefficient matrix, and determining a modulation and coding mode according to a modulation and coding mode of the modified channel, The number of streams is determined according to the rank of the modified channel coefficient matrix.

Optionally, the transmitting end sends the control information while transmitting data to the receiving end.

The embodiment of the present invention further discloses a data transmitting apparatus based on channel state information feedback. As shown in FIG. 4, the apparatus includes: a current channel state information acquiring module, a channel state information correcting module, a control information determining module, and data. Transmitting module;

Optionally, the channel state information correction module is specifically configured to correct a right singular vector of the current channel coefficient matrix according to a right singular vector of the historical channel coefficient matrix to obtain a right singular vector of the modified channel coefficient matrix, where the modified channel Right singular vector of coefficient matrix = ax Right singular vector of the pre-channel coefficient matrix + (la) x Right singular vector of the historical channel coefficient matrix, where 0 < a <= l.

Optionally, the channel state information correction module is specifically configured to correct a current channel coefficient correlation matrix according to a historical channel coefficient correlation matrix to obtain a modified channel coefficient correlation matrix, where the modified channel coefficient correlation matrix=b X current channel coefficient Correlation matrix + (lb) X historical channel coefficient correlation matrix, where 0 < b <= l.

Optionally, the channel state information correction module is specifically configured to correct a right singular vector of the current channel coefficient matrix according to a historical channel coefficient correlation matrix to obtain a right singular vector of the modified channel coefficient matrix, specifically, a historical channel coefficient. The correlation matrix R is decomposed into SVD: R = V ∑ V ^H ; thereafter, the right singular vector of the modified channel coefficient matrix is calculated = cx the right singular vector of the current channel coefficient matrix + (lc) Colum(y, dim), where 0 <C<=1, Colum( ,dim) is the pre-dim column of the matrix V, and dim is the number of columns of the right singular vector of the current channel coefficient matrix.

Optionally, the channel state information correction module is specifically configured to modify a modulation and coding mode of the current channel according to a modulation and coding manner of the historical channel, to obtain a modulation and coding mode of the modified channel, specifically, first calculating (dx current channel Modulating the coding mode + (ld) the value of the modulation coding mode of the X history channel, and then performing a rounding operation on the calculated value to obtain a modulation coding mode of the modified channel, where 0<d<=l.

Optionally, the channel state information correction module is specifically configured to correct the rank of the current channel coefficient matrix according to the rank of the historical channel coefficient matrix, to obtain a rank of the modified channel coefficient matrix, specifically, first calculating (ex current channel coefficient The rank of the matrix + (le) the value of the rank of the X historical channel coefficient matrix, and then rounding the calculated value to obtain the rank of the modified channel coefficient matrix, where 0 < e <= l.

It should be noted that, in the embodiment of the present invention, in the case of the right singular vector or the channel coefficient correlation matrix of the feedback channel coefficient matrix, the right singular vector or the channel coefficient correlation matrix of the channel coefficient matrix needs to be quantized, for example, when The receiving end responds to the transmitting end by means of a codebook. When the right singular vector of the channel coefficient matrix is fed, the right singular vector of the channel coefficient matrix is the precoding vector corresponding to the codebook.

The technical solution of the present invention will be further described in detail below with reference to specific embodiments. Example 1

FIG. 5 is a schematic diagram of channel state information modification in Embodiment 1 of the present invention. As shown in FIG. 5, the embodiment includes the following steps:

Step 501: The receiving end processes the signal such as the reference signal transmitted by the transmitting end to obtain current channel state information, and feeds back current channel state information to the transmitting end. The current channel state information may include one or more of the following: Current channel coefficient matrix The right singular vector, the historical channel coefficient correlation matrix, the modulation coding mode of the current channel, and the rank of the current channel coefficient matrix.

Step 502: After receiving the current channel state information fed back by the receiving end, the transmitting end corrects the current channel information based on the historical channel state information to obtain corrected channel state information.

Step 503: The transmitting end obtains control information according to the modified channel state information.

Step 504: The transmitting end transmits data to the receiving end according to the control information. Example 2

In this embodiment, the channel state information correction under a single transmitting end is taken as an example to illustrate the solution. FIG. 6 is a schematic diagram of channel state information modification in a single base station scenario in Embodiment 2, as shown in FIG. 6, the method includes:

Step 601: after a feedback time arrives, the current feedback from the receiver channel state information to the transmitting end cPMD cCQI _u.

Step 602: The transmitting end first corrects the CPMUP cCQI _u to obtain the corrected channel state information mW _u and mCQI _u .

mW _u and mCQI _u are modified precoding vectors and modified modulation coding modes, respectively. For symbolic meanings in other embodiments, reference may be made to this embodiment. Here, it is assumed before the transmitter has received the feedback from the receiver historical channel state information hPMIn and hCQI _u, hPMI _n the corresponding precoding vector hW _u, cPMI _n the corresponding precoding vector cW _u, the correct channel state information

mW _n =b cWn + (1-b) hW _n ;

mCQI _n =floor[c cCQI _n + (1-c) hCQI _u ].

It should be noted that mCQI _u can also be obtained as follows:

mCQI _u =cdl[c X cCQI _n + (1-c) hCQI _n ]

Or

mCQI _n =round[c cCQI _n + (1-c) hCQI _u ].

Floor is a rounding operation, ceil is a rounding operation, and round is a rounding operation. Step 603: The transmitting end uses mWu and mCQI _u to transmit data to the receiving end.

It should be noted that, when the correction scheme is not adopted, the transmitting end directly uses cPMIu and cCQI _u to transmit data to the receiving end. And the cPMI is a precoding matrix index fed back by the receiving end, corresponding to a precoding matrix, corresponding to cW _u in the embodiment, and the precoding matrix is usually a quantization of a right singular vector of the current channel coefficient matrix, Therefore, mWifb x cW _n + (1-b) χ hW _{n is} equivalent to the correction of the right singular vector of the current channel coefficient matrix, similar in other embodiments. Example 3

FIG. 7 is a schematic diagram of a method for correcting channel state information of a CB scenario according to Embodiment 3 of the present invention. As shown in FIG. 7, for the receiving end 1, the serving transmitting end is the transmitting end 1, and the cooperative transmitting end is the transmitting end 2, and the transmitting end 1 Sending data to the receiving end 1; although the transmitting end 2 can also cooperate with the transmitting end 1 to transmit data to the receiving end 2, in this embodiment, only the transmitting end 1 transmits data to the receiving end 1 by cooperation as an example, and Transmitter 2 still sends data to receiver 2 in a non-cooperative manner. The process includes:

Step 701: The receiving end 1 feeds back channel state information to the transmitting end 1, including PMI and CQI, specifically denoted as cPMI _u and cCQI _n ; the receiving end 2 feeds back the channel state letter to the transmitting end 1 and the transmitting end 2 Information, including PMI and CQI, respectively denoted as cPMI ₁₂ , cCQI ₁₂ , and cPMI ₂₂ , cCQI ₂₂ = Step 702: Transmitter 1 corrects cPMI _u , cCQI _u , cPMI ₁₂ , cCQI ₁₂ to obtain modified channel state information, Transmitter 2 corrects cPMI ₂₂ and cCQI ₂₂ to obtain corrected channel state information.

In the case that the transmitting end 1 performs the correction, it is assumed that the transmitting channel 1 has received the historical channel state information hPMU hCQI _u fed back by the receiving end 1 and the historical channel state information fed back by the receiving end 2

hCQIc hPMI _u corresponding to the precoding vector hW _{_u;} cPMI _u corresponding to the precoding vector cW _{u; hPMI} ₁₂ corresponding to the precoding vector hW _12; cPM ^ † corresponding precoding vector cW _12, the correction channel state information

mW _u =bx cWn + (lb)l/2 hW _n ;

mCQI _n =floor[c cCQI _n + (1-c) hCQI _n ];

mW ₁₂ = b cWi2 + (1-b) hW ₁₂ ;

mCQI ₁₂ = floor[cx cCQI ₁₂ + (1-c) hCQI ₁₂ ].

Thereafter, the receiving end 1 can determine the precoding vector used when transmitting data to the receiving end 1 as follows:

The CQI used when transmitting data to the receiving end 1 is determined based on mCQIu and mCQI ₁₂ . When the transmitting end 2 performs the correction, the modified channel state information used when transmitting data to the receiving end 2 can still be determined by referring to the method in Embodiment 2. Specifically, when the transmitting end 2 corrects the cPMI ₂₂ and the cCQI ₂₂ , Suppose the transmitting end before 2 has received the receiving end the second feedback channel state information hPMI ₂₂ and hCQI _{_22, hPMI 22} corresponding to the precoding vector hW _{_22;} cPMI ₂₂ corresponding to the precoding vector cW _22; the correct channel state information

mW ₂₂ = b cW22 + (1-b) χ hW ₂₂ ;

mCQI ₂₂ =floor[c χ cCQI ₂₂ + (1-c) χ hCQI ₂₂ ]

Step 703: The transmitting end 1 is based on mW _u , mCQI _u , mW ₁₂ , mCQI ₁₂ to the receiving end 1 Transmitting data, the transmitting end 2 uses mW ₂₂ and mCQI ₂₂ to transmit data to the receiving end 2. Example 4

FIG. 8 is a schematic diagram of channel state information modification in a single base station MU-MIMO scenario according to Embodiment 4 of the present invention. As shown in FIG. 8, the process includes:

Step 801: The receiving end 1 feeds back channel state information to the transmitting end, including PMI, CQI, and Rank, specifically as cPMI _u , cCQI _u , cRank _n ; the receiving end 2 feeds back channel state information to the transmitting end, including PMI, CQI, and Rank. , recorded as cPMI ₁₂ , cCQI ₁₂ , cRank ₁₂ .

Step 802: The transmitting end corrects cPMI _u and cCQI _u , obtains modified channel state information mW _u and mCQIn, and corrects cPMI ₁₂ and cCQI ₁₂ to obtain corrected channel state information mW ₁₂ and mCQI ₁₂ .

Here, the specific correction method is the same as that of the embodiment 2.

Step 803: The transmitting end sends data to the receiving end 1 based on mW _u , mCQI _u , and cRanku, and transmits data to the receiving end 2 by using mW ₁₂ , mCQI ₁₂ , and cRank ₁₂ .

It can be seen that the difference between this embodiment and the embodiment 2 is that the embodiment is a scenario of MU-MIMO, and each channel can adopt the channel state information correction method in the second embodiment. In addition, in this embodiment, only part of the current channel state information is corrected, for example, cRanku and cRank^ are not corrected. Example 5

FIG. 9 is a schematic diagram of channel state information modification in a SU-MIMO JT scenario in the embodiment. As shown in FIG. 9, the method includes:

Step 901: The receiving end feeds back channel state information to the transmitting end 1, including PMI, CQI, and Rank, specifically as cPMI _u , cCQI _u , cRank _n ; the receiving end feeds back channel state information to the transmitting end 2, including PMI, CQI, and Rank. , recorded as cPMI ₁₂ , cCQI ₁₂ , cRank ₁₂ .

Step 902: The transmitter 1 corrects the cPMI _u and cCQI _u to obtain a modified channel state letter. The information mW _u , mCQIn, and the transmitter 2 correct the cPMI ₁₂ and the cCQI ₁₂ to obtain the corrected channel state information mW ₁₂ and mCQI ₁₂ .

Here, the specific correction method is the same as that of the embodiment 2.

Step 903: The transmitting end 1 and the transmitting end 2 transmit data to the receiving end based on mW _u , mCQI _u , cRank _n , mW ₁₂ , mCQI ₁₂ , cRank ₁₂ .

It should be noted that, for Embodiments 2 to 5, if the receiving end feeds back the channel coefficient correlation matrix to the transmitting end, the SVD decomposition is performed on the current channel coefficient correlation matrix cR:

cR=V∑V ^H

mW = b X cW+(l-b) Colum(V,dim) , 0<b<=l.

Where Colum(V, dim) is the pre-dim column of the matrix V, and dim is the rank of the current channel coefficient matrix.

It should be noted that the transmitting end in the embodiment of the present invention may be a base station, a home base station, a relay station, or the like, or may be a communication terminal, a notebook computer, a handheld computer, or the like. Similarly, the receiving end is configured to receive the data signal of the transmitting end, and the receiving end may be a terminal device such as a mobile phone, a notebook computer, a handheld computer, or a control device such as a base station or a relay station.

The above description is only for the preferred embodiment of the present invention, and is not intended to limit the scope of the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included. Within the scope of protection of the present invention.

Claims

Claim

A data transmission method based on channel state information feedback, wherein the method includes: acquiring, by a transmitting end, current channel state information fed back by a receiving end;

2. The method according to claim 1, wherein

The method according to claim 2, wherein the transmitting end corrects the current channel state information according to the historical channel state information, and obtains the corrected channel state information as:

Correcting the modulation and coding mode of the current channel according to the modulation and coding mode of the historical channel, Obtaining a modulation and coding mode of the modified channel; or

4. The method according to claim 3, wherein

5. The method according to claim 3, wherein the correcting the right singular vector of the current channel coefficient matrix according to the historical channel coefficient correlation matrix to obtain the right singular vector of the modified channel coefficient matrix is:

SVD decomposition of the historical channel coefficient correlation matrix R: R = V ∑ V ^H ;

Correct the right singular vector of the channel coefficient matrix = cx the right singular vector of the current channel coefficient matrix + (lc) Colum(V, dim), where 0<C<=1, Colum(V, dim) is taken before the matrix V The dim column, dim is the number of columns of the right singular vector of the current channel coefficient matrix.

6. The method according to claim 3, wherein

The method according to any one of claims 1 to 6, wherein the control information comprises one or more of the following: a precoding vector, a stream number, a modulation and coding method used when the transmitting end sends data to the receiving end. And determining a precoding vector according to a right singular vector of the modified channel coefficient matrix, determining a modulation coding mode according to a modulation coding manner of the modified channel, and determining a flow number according to a rank of the modified channel coefficient matrix.

8. A data transmitting apparatus based on channel state information feedback, wherein the apparatus comprises: a current channel state information acquiring module, a channel state information correcting module, a control information determining module, and a data transmitting module;

9. The apparatus according to claim 8, wherein

The channel state information correction module is specifically configured to be based on the right of the historical channel coefficient matrix The singular vector corrects the right singular vector of the current channel coefficient matrix to obtain a right singular vector of the modified channel coefficient matrix, the right singular vector of the modified channel coefficient matrix = ax the right singular vector of the current channel coefficient matrix + (la) X history The right singular vector of the channel coefficient matrix, where 0 < a <= l.

The device according to claim 8, wherein the channel state information correction module is specifically configured to correct a current channel coefficient correlation matrix according to a historical channel coefficient correlation matrix to obtain a modified channel coefficient correlation matrix, and the modified channel Coefficient correlation matrix = b < current channel coefficient correlation matrix + (lb) x historical channel coefficient correlation matrix, where 0 < b <= l.

11. The apparatus according to claim 8, wherein

The channel state information correction module is specifically configured to correct the right singular vector of the current channel coefficient matrix according to the historical channel coefficient correlation matrix to obtain a right singular vector of the modified channel coefficient matrix, specifically, the historical channel coefficient correlation matrix R is SVD decomposition: R = V ∑ V ^H ; Then, calculate the right singular vector of the modified channel coefficient matrix = cx the right singular vector of the current channel coefficient matrix + (lc) X Colum (V, dim), where 0 < C <= 1 , Colum , dim ) is the pre-dim column of the matrix V, and dim is the number of columns of the right singular vector of the current channel coefficient matrix.

The device according to claim 8, wherein the channel state information correction module is specifically configured to modify a modulation and coding mode of the current channel according to a modulation and coding mode of the historical channel, to obtain a modulation and coding mode of the modified channel, First, calculate (dx the modulation coding mode of the current channel + (ld) the modulation coding mode of the X history channel), and then perform a rounding operation on the calculated value to obtain a modulation coding mode of the modified channel, where, 0 <d<=l.

The device according to claim 8, wherein the channel state information correction module is specifically configured to correct the rank of the current channel coefficient matrix according to the rank of the historical channel coefficient matrix, to obtain the rank of the modified channel coefficient matrix, First, calculate (the rank of the current channel coefficient matrix + (le) the rank of the X historical channel coefficient matrix), and then perform a rounding operation on the calculated value to obtain the rank of the modified channel coefficient matrix, where, 0 <e<=l.