WO2013139186A1 - Channel information feedback method, apparatus, and system - Google Patents

Abstract

Disclosed are a channel information feedback method, apparatus, and system, relating to the technical field of communications. An embodiment of the present invention provides a channel information feedback method, comprising: a feedback link sending end obtaining a channel matrix; the feedback link sending end selecting a first codeword from a codebook according to the channel matrix and a first reference matrix; and the feedback link sending end sending the sequence number of the first codeword to a feedback link receiving end. The channel information feedback method, apparatus, and system provided by the embodiments of the present invention can be applied in a scenario of a slow channel change, for example, a radio channel, a channel on an adjacent sub-carrier in a MIMO-OFDM system, and the like, and can implement high-precision channel information feedback.

Description

 The present invention claims the priority of the Chinese application filed on March 23, 2012, the application number is 201210081621.8, and the invention name is "method, device and system for channel information feedback", the entire contents thereof This is incorporated herein by reference. Technical field

 The present invention relates to the field of communications technologies, and in particular, to a method, device, and system for channel information feedback. Background technique

 Long Term Evolution-Advanced in Long Term Evolution based on Multiple-Input Multiple-Output (MIMO)-Orthogonal Frequency Division Multiplexing (OFDM) technology In the LTE-A system, the codebook-based implicit feedback scheme is gradually developed in the research of single-user MIMO systems. The basic feature is that the user equipment selects the precoding matrix and then pre- The coding matrix is fed back to the base station. In a single-user MIMO system, multiple data streams belong to the same user. The purpose of channel information feedback is to help the base station implement precoding, so that the base station avoids the characteristic direction of deep fading in the wireless channel by precoding, and obtains a good Propagation gain, and mutual interference of multiple data streams can be eliminated by receiving processing (such as Minimum Mean Square Error (MMSE) receiver), so high feedback accuracy is not required.

However, with the emergence of technologies such as multi-user MIMO and Coordinated Multiple Points (CoMP), multiple data streams in a multi-user system belong to different users, and the main function of the base station precoding operation is to eliminate users. Inter-interference, which requires more accurate channel information. The codebook-based implicit feedback method provided in the prior art cannot satisfy the feedback of multi-user systems. Degree requirements.

Summary of the invention

 The embodiment of the invention provides a method, a device and a system for channel information feedback, which solves the problem that the implicit feedback method based on the codebook cannot meet the requirements of the multi-user system for feedback accuracy.

 In one aspect, a method for providing channel information feedback includes: a feedback link transmitting end acquiring a channel matrix; and a feedback link sending end selecting a first codeword from the codebook according to the channel matrix and the first reference matrix, The codebook includes a plurality of codewords arranged by a sequence number, the plurality of codewords being a matrix for quantizing a variation between a main feature matrix of the channel matrix and the first reference matrix; the feedback link The sending end sends the sequence number of the first codeword to the feedback link receiving end.

 In another aspect, a method for channel information feedback is provided, including: receiving, by a receiving end of a feedback link, a sequence number of a first codeword sent by a sending end of the feedback link; The sequence number of the codeword is selected from the codebook, the codebook includes a plurality of codewords arranged by a sequence number, the plurality of codewords being a main feature matrix of the quantized channel matrix and the first reference a matrix of the amount of change between the matrices; the feedback link receiving end generates a second reference matrix according to the first codeword and the first reference matrix.

 In one aspect, a feedback link sender is further provided, including:

 An obtaining unit, configured to acquire a channel matrix;

 a first selecting unit, configured to select a first codeword from the codebook according to the channel matrix and the first reference matrix, where the codebook includes multiple codewords arranged by a sequence number, where the multiple codewords are quantized a matrix of the amount of change between the main feature matrix of the channel matrix and the first reference matrix; the first sending unit, configured to send the sequence number of the first codeword selected by the first selecting unit to the feedback link for receiving end.

 In another aspect, a feedback link receiving end is provided, including:

a first receiving unit, configured to receive a sequence number of the first codeword sent by the sending end of the feedback link, and a second selecting unit, configured to select the first number from the codebook according to the sequence number of the first codeword a codeword, the codebook includes a plurality of codewords arranged according to a sequence number, wherein the plurality of codewords are a matrix of a quantity of change between a main feature matrix of the quantization channel matrix and the first reference matrix;

 a second generating unit, configured to generate a second reference matrix according to the first codeword selected by the second selecting unit and the first reference matrix.

 In another aspect, a communication system is provided, including:

 a feedback link transmitting end, configured to acquire a channel matrix, select a first codeword from the codebook according to the channel matrix and the first reference matrix, and send the sequence number of the first codeword to a feedback link receiving end;

 a feedback link receiving end, configured to receive a sequence number of the first codeword sent by the sending end of the feedback link, and select the first codeword from the codebook according to the sequence number of the first codeword, according to the first Generating a second reference matrix by a codeword and a first reference matrix;

 The codebook includes a plurality of codewords arranged by a sequence number, and the plurality of codewords are a matrix for quantizing a variation between a main feature matrix of the channel matrix and the first reference matrix.

 The method, device and system for channel information feedback provided by the embodiments of the present invention use the main feature matrix of the channel matrix as a feedback object, and the main feature matrix is the effective channel information required for calculating the precoding matrix by the receiving end of the feedback link. That is, the minimum channel information required by the receiving end of the feedback link to calculate the precoding matrix, so that the feedback amount can be reduced from the source, and the codeword that quantifies the variation between the main feature matrix and the reference feature space by feedback is Differential feedback, in the general low-speed moving work scene, has strong time correlation, differential feedback can make full use of this time redundant information, further reduce the feedback amount, the code word is used to quantify the feedback amount, feedback The smaller the amount, the higher the feedback accuracy, thus achieving higher feedback accuracy. DRAWINGS

 FIG. 1 is a flowchart 1 of a method for channel information feedback according to Embodiment 1 of the present invention;

 2 is a flowchart 2 of a method for channel information feedback according to Embodiment 1 of the present invention;

3 is a flowchart of a method for channel information feedback according to Embodiment 2 of the present invention; Figure 4 (a) is the average chord distance between the channel feature space feedback value and its true value in an antenna configuration with 4 rounds and 2 rounds;

 Figure 4 (b) shows the simulation results of the system capacity in the antenna configuration of 4 rounds and 2 receivers;

 Figure 4 (c) is the average chord distance between the channel feature space feedback value and its true value in the antenna configuration of 8 rounds and 8 receivers;

 Figure 4 (d) shows the simulation results of the system capacity in the antenna configuration of 8 rounds and 8 rounds;

 FIG. 5 is a flowchart of a method for channel information feedback according to Embodiment 3 of the present invention;

 FIG. 6 is a schematic structural diagram 1 of a transmitting end of a feedback link according to Embodiment 4 of the present invention; FIG. 7 is a schematic structural diagram of a first selecting unit in a transmitting end of a feedback link shown in FIG. 6; FIG. 8 is a schematic diagram of Embodiment 4 of the present invention; FIG. 9 is a schematic structural diagram 1 of a transmitting end of a feedback link according to Embodiment 4 of the present invention; FIG. 10 is a schematic structural diagram 2 of a transmitting end of a feedback link according to Embodiment 4 of the present invention; A system architecture diagram of a communication system provided in Embodiment 5 of the present invention. detailed description

 In the following description, for purposes of illustration and description However, it will be apparent to those skilled in the art that the present invention may be practiced in other embodiments without these specific details. In other instances, detailed descriptions of well-known devices, circuits, and methods are omitted so as not to obscure the description of the invention. Embodiments of the present invention provide a method, device, and system for feeding back channel information, and implementing channel information feedback with higher precision.

Embodiment 1

As shown in FIG. 1 , an embodiment of the present invention provides a method for channel information feedback. Can be applied to the feedback link sender, including:

 101. Obtain a channel matrix.

 102. Select a first codeword from a preset codebook according to the channel matrix and the first reference matrix.

 The codebook includes a plurality of codewords arranged according to a sequence number, wherein the plurality of codewords are a matrix that quantizes a variation between a main feature matrix of the channel matrix and the first reference matrix, the main The feature matrix is the effective channel information required when the link receiving end calculates the precoding matrix.

 As an implementation manner, the step 102 may be implemented by: selecting, according to the channel matrix and the first reference matrix, a power gain max as a standard, selecting the first one from the preset codebooks. The codeword, or the first codeword is selected from the pre-set codebook as the standard. The specific implementation manner is not limited to the above two modes, and is not described here.

 As an implementation manner, the first reference matrix may be configured to be generated by: if the channel information is fed back at an initial time, the feedback link sending end acquires the same number of main feature matrix rows as the channel matrix. The 酉 matrix, the arbitrarily selected M columns are set as the first reference matrix, and the M columns are the number of columns of the main feature matrix of the channel matrix; if the channel information feedback is not at the initial time The feedback link sending end generates the first according to the first codeword when the channel information is fed back and the reference matrix when the channel information is feedbacked last time.

103. Send the sequence number of the first codeword to the feedback link receiving end.

 As shown in FIG. 2, the embodiment of the present invention further provides a method for feeding back channel information, which can be applied to a receiving end of a feedback link, including:

 201. Receive a sequence number of the first codeword sent by the sending end of the feedback link.

202. Select, according to the sequence number of the first codeword, the first codeword from a preset codebook. The codebook includes a plurality of codewords arranged by a sequence number, and the plurality of codewords are a matrix of a variation amount between a main feature matrix of the quantization channel matrix and the first reference matrix, where the channel matrix The main feature matrix is the effective channel information required to calculate the precoding matrix.

 As an implementation manner, the first reference matrix may be obtained by: if the channel information is fed back at an initial moment, the feedback link receiving end acquires the same number of rows as the main feature matrix of the channel matrix. a matrix, an arbitrary M column selected from the unitary matrix is set as the first reference matrix, and the M column is a number of columns of a main feature matrix of the channel matrix; if the channel information feedback is not at an initial moment, The feedback link receiving end uses the generated second reference matrix when the channel information is fed back as the first reference matrix. The specific implementation manner is not limited to the above two methods, and is not described here.

 203. Generate a second reference matrix according to the first codeword and the first reference matrix.

 Optionally, the feedback link receiving end may send the second reference matrix to the forward link to perform a precoding operation to match the channel so that the information in the channel obtains a large gain in the transmission.

 The second reference matrix in the embodiment of the present invention can be used as the first reference matrix of the feedback link receiving end when the next channel information is fed back, and the method steps 201-203 are performed to complete the next channel information feedback.

 In the first embodiment of the present invention, the receiving end of the feedback link may be a base station, and the sending end of the feedback link may be a user equipment.

In the channel information feedback method provided by the embodiment of the present invention, the feedback link sending end selects the first codeword from the preset codebook according to the channel matrix and the first reference matrix, and sends the sequence number of the first codeword to the feedback. a receiving end of the link; after receiving the sequence number of the first codeword, the receiving end of the feedback link selects the first codeword in the codebook according to the sequence number, and generates a second reference according to the first codeword and the first reference matrix. Matrix, thus achieving feedback of channel information. In the first embodiment of the present invention, the main feature matrix matrix is used as the feedback object, and the main feature matrix of the main feature matrix is the effective channel information required for calculating the precoding matrix of the feedback link receiving end, that is, the feedback link receiving end calculates the precoding matrix. The minimum channel information required, so that the amount of feedback can be reduced from the source. Moreover, the codeword that quantifies the amount of change between the main feature matrix main feature matrix and the reference feature space by the feedback amount belongs to differential feedback, and has a strong time correlation in a general low-speed moving work scenario, and the differential feedback may be This redundant information is sufficient to further reduce the amount of feedback. The codeword is used to quantify the feedback amount. The smaller the feedback amount, the higher the feedback accuracy, thus achieving higher feedback accuracy.

Embodiment 2

In order to enable a person skilled in the art to better understand the method of channel information feedback provided by the embodiment of the present invention, the method will be described in detail. In the present embodiment, the channel information feedback method is applied to a multiuser MIMO system, the system is provided antenna N _t N _r receive hair configuration, the system is a MIMO channel experiences frequency flat Rayleigh fading, and in one The time block T _Blk (or during the channel information feedback) remains unchanged. As shown in FIG. 3, the method for channel information feedback provided by the embodiment of the present invention includes:

 301. The user equipment acquires a channel matrix.

In this embodiment, the channel matrix is an N _t *N _r random matrix H ( t ) composed of channel fading coefficients between pairs of antennas. In the tth time block, the fading coefficient from the transmitting antenna n to the propagation path receiving the receiving antenna m can be represented by a random variable h _m , _n ( t ).

 302. The user equipment selects the first codeword from the preset codebook according to the channel matrix and the first reference matrix, using a maximum power gain as a standard.

The codebook is composed of a plurality of codewords arranged according to a sequence number, and the number of codewords is determined by the feedback amount of the entire feedback link, and each codeword is one (N _t -M ) *M (M is a matrix of the number of column vectors of the main feature matrix of the channel matrix, which is a matrix for quantizing the residual, the residual being a change between the main feature matrix of the channel matrix and the first reference feature matrix The main feature matrix of the channel matrix is effective channel information required when the feedback link receiving end calculates a precoding matrix. It is worth noting that the codebook is stored in the feedback link sender and the feedback link receiver after being pre-set. Optionally, at the initial moment of channel information feedback, the first reference matrix of the feedback link transmitting end and the first reference matrix of the feedback link receiving end are the same. Specifically, the step 302 is implemented by: acquiring, by the user equipment, an orthogonal complement matrix of the first reference matrix, and then orthogonal according to the channel matrix, the first reference matrix, and the first reference matrix. The complement matrix, the power gain max is used as a standard to select the first codeword from the preset codebook. There are various algorithms for solving the orthogonal complement matrix of the first reference matrix. In this embodiment, the QR decomposition method is used.

In this embodiment, if the channel feedback is at an initial moment, the first reference matrix may be a preset initial value: first acquiring a unitary matrix of N _t x N _t , and selecting an arbitrary M from the unitary matrix N _t x M, sets N _t x M as the first reference matrix, where M is the number of column vectors of the main feature matrix of the channel matrix. If the channel information feedback is not at the initial time, the first reference matrix is generated by the first code matrix when the user equipment feeds back according to the previous channel information and the first reference matrix when the previous channel information is fed back.

 Specifically, when the channel information feedback is not at the initial moment, the first reference matrix may be implemented based on the tangent space theory of the Grassmann manifold, and is specifically implemented by the following formula: ϋ(ί) = qrd{(j{t - 1) + Oiit - ^)D(t - 1)} where: is the first reference matrix; qrd{ } is a QR decomposition operator; ϋ{ί -\) the reference of the last channel information feedback a matrix; - 1) an orthogonal complement matrix of the reference matrix when the last channel information is fed back; D(tl) is the first codeword when the last channel information is fed back.

In this embodiment, the step 302 may select the first codeword by using the following formula based on the maximum power: (/ ¹ ) = arg max H{t) * qrd{U{t) + ut) C)

Ce codebook\F where D(t) is the first codeword; arg _max || || _F is the codeword used to select the power gain most c _e codebook from the codebook; H(t Is the channel matrix; qrd{ } is a QR decomposition operator; is the first reference matrix; is an orthogonal complement matrix of the first reference matrix; C is a codebook a code word.

 303. The user equipment sends the sequence number of the first codeword to the base station (feedback link receiving end).

304. The receiving end of the base station receives the sequence number of the first codeword sent by the user equipment.

 305. The base station selects the first codeword from a preset codebook according to the sequence number of the first codeword.

 The codebook preset in the base station is the same as the codebook preset in the user equipment, and includes a plurality of codewords arranged by a sequence number, where the multiple codewords are main feature matrices of the quantized channel matrix. A matrix of the amount of change between the first reference matrices, the main feature matrix being effective channel information required when the pre-coding matrix is calculated by the link receiving end.

 306. The base station generates a second reference matrix according to the first codeword and the first reference matrix. The setting manner of the first reference matrix is: if the channel feedback is at an initial moment, the feedback link receiving end sets the first reference matrix to be the same as the first reference matrix set by the user equipment at the initial time of the channel feedback; If the channel information feedback is not at the initial time, the feedback link receiving end uses the generated second reference matrix when the channel information is fed back as the first reference matrix.

 Optionally, the base station may send the second reference matrix to the forward link to perform a precoding operation to match the channel so that the information in the channel obtains a large gain in the transmission.

 In this embodiment, the manner in which the second reference matrix is generated may be implemented by using the following formula:

 U(t + 1) = qrd{U(t) + U{t)D{t)} where: ( + ι) is the second reference matrix; Γί {·} is the decomposition operator; tl t, The first reference matrix; ^^0) is an orthogonal complement matrix of the first reference matrix; DO) is the first codeword.

It is worth noting that the method of feedback channel information provided in the second embodiment has been simulated and evaluated. In the simulation, the wireless channel has no frequency selectivity, and the time is lms. The bit changes to 4匕, and the rule of 4匕 is: H(t, = aH(t _ X) + (t, .

The parameters "and = is the correlation coefficient determined by the Jakes channel model; Δ) is the Gaussian incremental signal with 0 mean unit variance, and its properties are the same as the additive white Gaussian noise. Under the Jakes channel model, the correlation of adjacent time channels The coefficient satisfies = J ₀ ( ^l7tfcTm ^ ^UE ).

3 x10 ^s

Among them, J. (q>zero order first class Bessel function; _ denotes carrier frequency, set to 1.8 GHz in simulation; J _TO denotes the time interval considered, set to lms in simulation; _s denotes user equipment moving speed, consider in simulation There are many situations in the range of 3 to 30 km/h.

 Firstly, the antenna configuration of 4 rounds and 2 receivers is examined. The system uses beamforming technology, and only needs to feed back the main feature matrix of the main feature matrix of one dimension. The feedback uses a 3-bit codebook, which is fed back every 1 ms, and assumes that there is no delay in the feedback channel. Figure 4 (a) is the average chord distance between the channel feature space feedback value and its true value, where the rightmost one represents the memoryless feedback method and the corresponding codebook used in the Rel.8 standard. The 4 bit codebook is used in the Rel. 8 standard, and the feedback amount is larger than the channel information feedback method provided by the second embodiment of the present invention. However, as can be seen from the figure, in the method for channel information feedback provided by the second embodiment of the present invention, when the user equipment corresponds to different moving speeds, the average value of the chord distance between the feedback value and the true value is: 3 km. /h is between 0 and 0.05, between 10 and 0.05 at 10 km/h, between 0.2 and 0.25 at 20 km/h, and between 0.3 and 0.35 at 30 km/h. In the conventional feedback method, the average value of the chord distance between the feedback value and the true value is greater than 0.55. Therefore, the channel information feedback method provided by the embodiment of the present invention is better than the algorithm in the Rel.8 standard. Figure 4 (b) shows the simulation results of the system capacity. For ease of observation, the system capacity in the case of full channel status information is used as a reference value. It can be seen that, in the method for channel information feedback provided by the second embodiment of the present invention, when the user equipment corresponds to different moving speeds, the transmission throughput is greater than 95%, and the traditional feedback method has a transmission throughput of less than 85%. It can be seen that the method for channel information feedback provided by the embodiment of the present invention is obviously superior to the method used by Rel.

Secondly, it also examined the antenna configuration of 8 rounds and 8 rounds, and 4 sets the main feature matrix of the main characteristic matrix which needs to feed back 4 dimensions. Use 6-bit codebook for feedback, feedback every 1 ms, and assume that the feedback channel is not There is a delay. Figure 4 (c) is the average chord distance between the channel feature space feedback value and its true value, so that the average value of the chord distance between the feedback value and the true value is less than 0.55 at a moving speed of 30 km/h. Figure 4 (d) shows the simulation results of the system capacity. It can be seen that even at a moving speed of 30 km/h, a channel capacity of more than 92% can be obtained.

 The embodiment of the present invention uses the main feature matrix main feature matrix as the feedback object, because the main feature matrix is the effective channel information required for the feedback link receiving end to calculate the precoding matrix, that is, the feedback link receiving end needs to calculate the precoding matrix. Minimum channel information, so that the amount of feedback can be reduced from the source, and the codeword that quantifies the amount of change between the main feature matrix and the reference feature space by feedback is a differential feedback, and in a general low-speed moving work scene, there is Strong time correlation, differential feedback can fully reduce the redundant information in this time, further reduce the feedback amount, the code word is used to quantify the feedback amount, the smaller the feedback amount, the higher the feedback precision, thus achieving a higher Feedback accuracy.

Embodiment 3

In order to enable a person skilled in the art to better understand the method for feeding back channel information provided by the embodiment of the present invention, the method will be described in detail. In this embodiment, the method is applied to feedback channel information of a multiuser MIMO system, the system is provided antenna N _t N _r receive hair configuration, the system is a MIMO channel experiences frequency flat Rayleigh fading, and in one The time block _tt remains unchanged. As shown in FIG. 5, the method for feeding back channel information provided by the embodiment of the present invention includes:

 501. The user equipment acquires a channel matrix.

 The specific implementation of the step 501 is the same as the foregoing step 301, and details are not described herein again.

502. The user equipment selects the first codeword from a preset codebook according to the channel matrix and the first reference matrix by using a minimum matrix distance as a standard.

Wherein, the codebook is composed of a plurality of codewords arranged according to the serial number, and the number of the codewords is determined by the feedback amount of the entire feedback link, and each codeword is a matrix of ( _Nt- M)*M, which is used And a matrix of quantized residuals, wherein the residual is a main feature matrix main feature matrix of the channel matrix and the parameter According to the variation between the feature spaces, the main feature matrix of the channel matrix is the effective channel information required when the feedback link receiving end calculates the precoding matrix. It is worth noting that the codebook is stored in both the feedback link sender and the feedback link receiver.

 Specifically, first, the user equipment acquires a main feature matrix of the channel matrix and an orthogonal complement matrix of the first reference matrix. Then, according to the main feature matrix, the first reference matrix and the orthogonal complement matrix of the first reference matrix, the first codeword is selected from a preset codebook by using a matrix distance minimum as a standard.

 The specific implementation manner of acquiring the main feature matrix of the channel matrix is:

 The channel matrix is characterized by the following formula:

its

According to the eigen decomposition, the M-order main feature matrix of the channel is defined as the def of the first M eigenvectors.

Nt xM orthogonal unit matrix: U(t, = [u, (t), ..., u _M (t)]. The column space of the main feature matrix is the space in which each column vector is formed. The subspace, called the main feature matrix of the channel, is denoted as U(t), where is the N _t dimensional vector matrix, that is, the set of all N _t dimensional complex vectors.

 The method for obtaining the orthogonal complement matrix of the first reference matrix is the same as the specific implementation of the foregoing step 302, and details are not described herein again.

 In an embodiment, the step 502 can be implemented by the following formula:

 D(t) = arg min^(^ (0 , qrd{0 (t) + (j i ( )C})

 a codebook, where D(t) is the first codeword; arg min^O is a codebook selected from the codebook

The codeword used by the matrix with the smallest distance between the main feature matrices of the matrix; d( ) is the distance operator between matrices; qrd{ } is the QR decomposition operator; U ( t ) is the main feature of the channel matrix matrix; Is the first reference matrix; O is an orthogonal complement matrix of the first reference matrix; c is a codeword in the codebook.

Multiple metrics can be defined in a Grassmann manifold, considering two elements in G(N _t , M)

[χ],

[Y]. Let σ ^,., σΜ denote the singular values of Χ*Υ, which are determined by [Χ], [Υ], and are independent of the choice of the representative matrix. These singular values are between 0 and 1, so the angle ^^arccos^ V can be defined, which is called the Principal angle between the two subspaces corresponding to [X][Y]. The metric d ( ) in the Grassmann manifold can be defined by these protagonists. For example, geodesic distance: ά _§ {[χΐ[Υ ) = _ι ² + ₂ ² +...+ _Μ ²

Fubini-Study: d _FS ([ ],[Γ]) = arccos( χ ₂ χ...χσ _Μ )

Projection 2-norm distance: ₂ ([ ],m) = max _M {sin } String giant d _c ^si ² _ι + ... + sin ² ^ _M

 In the study of channel information feedback, Fubini-Study distance, projection 2-norm distance, chord distance, etc. on Grassmann manifold have been used as feedback metrics for feedback.

 503. The user equipment sends the sequence number of the first codeword to the base station (feedback link receiving end).

 504. The base station receiving end receives the sequence number of the first codeword sent by the user equipment.

 505. The base station selects the first codeword from a preset codebook according to the sequence number of the first codeword.

 The codebook preset in the base station is the same as the codebook preset in the user equipment, and includes a plurality of codewords, where the codeword is a main feature matrix for quantizing a channel matrix and the first reference A matrix of the amount of change between the matrices, the main feature matrix being the effective channel information required when the pre-coding matrix is calculated by the link receiving end.

506. The base station root generates a second reference matrix according to the first codeword and the first reference matrix. The setting manner of the first reference matrix is: if the channel feedback is at an initial moment, The feedback link receiving end acquires the same 酉 matrix as the main feature matrix row number of the channel matrix, and selects any M column from the 酉 matrix to be set as the first reference matrix, and the M column is the The number of columns of the main feature matrix of the channel matrix; if the channel information feedback is not at the initial time, the feedback link receiving end uses the generated second reference matrix when the channel information is fed back as the first reference matrix.

 Optionally, the feedback link receiving end may send the second reference matrix to the forward link to perform a precoding operation to match the channel so that the information in the channel obtains a large gain in the transmission.

 In this embodiment, the manner in which the second reference matrix is generated may be implemented by using the following formula:

 U(t + 1) = qrd{U(t) + U{t)D{t)}

 Wherein: + is the second reference matrix; Γί {·} is a QR decomposition operator; is the first reference matrix; ^^0) is an orthogonal complement matrix of the first reference matrix; DO) is Said the first code word.

In the channel information feedback method provided by the embodiment of the present invention, the feedback link sending end selects the first codeword from the preset codebook according to the channel matrix and the first reference matrix, and sends the sequence number of the first codeword to the feedback. The receiving end of the link thus implements feedback of channel information, wherein the codebook includes a plurality of codewords, and the codeword is used to quantize changes between the main feature matrix of the channel matrix and the first reference matrix a matrix of quantities, the main feature matrix is effective channel information required when the pre-coding matrix is calculated by the link receiving end; by using the main feature matrix as a feedback object, the pre-coding is calculated by the main feature matrix as the feedback link receiving end The effective channel information required by the matrix, that is, the minimum channel information required by the receiving end of the feedback link to calculate the precoding matrix, so that the feedback amount can be reduced from the source, and the main feature matrix and the reference feature space are quantized by feedback. The code word of the amount of change, which belongs to differential feedback, has a strong time correlation in the general low-speed moving work scene. Differential feedback can fully reduce the redundant information in this time, further reduce the feedback amount. The codeword is used to quantify the feedback amount. The smaller the feedback amount, the higher the feedback accuracy. Thereby achieving a higher feedback accuracy.

 The first embodiment to the third embodiment of the present invention can be combined with each other to generate other method embodiments that can be understood by those skilled in the art, and details are not described herein again. Embodiment 4

 As shown in FIG. 6, the embodiment of the present invention provides a feedback link sending end, which includes: an obtaining unit 61, configured to acquire a channel matrix;

 a first selecting unit 62, configured to select, according to the channel matrix and the first reference matrix, a first codeword from a preset codebook, where the codebook includes multiple codewords, where the codeword is used for quantization a matrix of a variation between a main feature matrix of the channel matrix and the first reference matrix, wherein the main feature matrix is effective channel information required when the pre-coding matrix is calculated by the link receiving end;

 As shown in FIG. 7, the first selecting unit may include:

 a first selecting subunit 621, configured to select the first codeword from the preset codebook according to the channel matrix and the first reference matrix, using a maximum power gain as a standard; and/or

 The second selection sub-unit 622 is configured to select the first codeword from a preset codebook by using a matrix distance minimum as a standard.

In an embodiment, the first selecting subunit is configured to select the first code from the preset codebook according to the channel matrix and the first reference matrix, using a maximum power gain as a standard. The word is specifically used by the following formula: (/ ¹ ) = argmax H(t) * qrd{U(t) + ut)C}

Ce codebook\F where D(t) is the first codeword; arg _max || || _F is the codeword used to select the power gain most c _e codebook from the codebook; H(t Is the channel matrix; qrd{ } is a QR decomposition operator; is the first reference matrix; (7 is an orthogonal complement matrix of the first reference matrix; C is a codebook a code word.

 In this embodiment, the second selecting sub-unit is configured to select the first codeword from a preset codebook by using a minimum matrix distance as a standard, which is specifically implemented by using the following formula:

 D(t) = arg min^(^ (0 , qrd{0 (t) + (j i ( )C})

 a codebook, where D(t) is the first codeword; arg min^O is a codebook selected from the codebook

The codeword used by the matrix with the smallest distance between the main feature matrices of the matrix; d( ) is the distance operator between matrices; qrd{ } is the QR decomposition operator; U ( t ) is the main feature of the channel matrix a matrix; is the first reference matrix; (7 is an orthogonal complement matrix of the first reference matrix; C is a codeword in a codebook.

 The first sending unit 63 is configured to send the sequence number of the first codeword selected by the first selecting unit to the feedback link receiving end.

 As shown in FIG. 8, the feedback link sending end further includes:

 a first setting unit 64, configured to: if the channel information is fed back at an initial time, the acquiring a unitary matrix having the same number of main feature matrix rows as the channel matrix, and selecting any M column from the unitary matrix to be set to The first reference matrix, the M columns being the number of columns of the main feature matrix of the channel matrix;

 The first generating unit 65 is configured to generate the first reference matrix according to the codeword when the channel information is fed back and the reference matrix when the channel information is fed back, if the channel information feedback is not at the initial time.

 In this embodiment, the first generating unit generates the first reference according to a codeword when the channel information is fed back and a reference matrix when the channel information is fed back, if the channel information feedback is not at the initial time. The matrix is specifically implemented by the following formula:

(7(0 = qrd{(j{t - 1) + Oiit - ^)D(t - 1)} where is the first reference matrix; qrd{ } is a QR decomposition operator; 1) is a reference matrix when the channel information is fed back last time; - 1) is an orthogonal complement matrix of the reference matrix when the last channel information is fed back; D(tl) is a codeword when the last channel information is fed back.

 As shown in FIG. 9, the embodiment of the present invention further provides a feedback link receiving end, including: a first receiving unit 91, configured to receive a sequence number of a first codeword sent by a sending end of the feedback link;

 a second selecting unit 92, configured to select the first codeword from a preset codebook according to the sequence number of the first codeword, where the codebook includes multiple codewords, where the multiple codewords are used a matrix for quantizing a variation between a main feature matrix of the channel matrix and the first reference matrix, the main feature matrix being effective channel information required when the pre-coding matrix is calculated by the link receiving end;

 The second generating unit 93 is configured to generate a second reference matrix according to the first codeword selected by the second selecting unit and the first reference matrix.

 Optionally, the feedback link receiving end may send the second reference matrix to the forward link to perform a precoding operation to match the channel so that the information in the channel obtains a large gain in the transmission.

 In this embodiment, the second generating unit is configured to generate a second reference matrix according to the first codeword selected by the second selecting unit and the first reference matrix, and is implemented by using the following formula:

 0{t) = qrd{0(t - 1) + ϋι_(ί l)D(t)} where is the second reference matrix; qrd{ } is the QR decomposition operator; ϋ{ί - \) The generated second reference reference matrix when the channel information is fed back; 1) the orthogonal complement matrix of the second reference frame when the last channel information is fed back; D(t) is the first codeword .

 Further, as shown in FIG. 10, the feedback link receiving end further includes:

a second setting unit 94, configured to acquire a unitary matrix having the same number of rows as the main feature matrix of the channel matrix, and select any M column from the unitary matrix to be set as the first reference matrix, where the M column is The number of columns of the main feature matrix of the channel matrix; The third setting unit 95 is configured to use, as the first reference matrix, the generated second reference matrix when the channel information is fed back, if the channel information feedback is not at the initial time.

 The feedback link transmitting end and the feedback link receiving end provided by the embodiment of the present invention use the main feature matrix as a feedback object, and the main feature matrix is used as a feedback link receiving end to calculate effective channel information required by the precoding matrix, that is, The feedback link receiving end calculates the minimum channel information required by the precoding matrix, so that the feedback amount can be reduced from the source, and the codeword that quantifies the variation between the main feature matrix and the reference feature space by feedback is a difference Feedback, in the general low-speed moving work scene, there is strong time correlation, differential feedback can fully reduce the redundant information in this time, further reduce the feedback amount, the code word is used to quantify the feedback amount, the more the feedback amount The higher the accuracy of the small feedback, the higher the feedback accuracy. Embodiment 5

 The embodiment of the present invention provides a channel information feedback system, as shown in FIG. 11, including: a feedback link transmitting end 1101, configured to acquire a channel matrix, and according to the channel matrix and the first reference matrix, from a preset codebook. Selecting a first codeword, and transmitting the sequence number of the first codeword to a receiving end of the feedback link;

 a feedback link receiving end 1102, configured to receive a sequence number of the first codeword sent by the sending end of the feedback link, and select the first codeword from a preset codebook according to the sequence number of the first codeword, Generating a second reference matrix according to the first codeword and the first reference matrix;

 Optionally, the feedback link receiving end may send the second reference matrix to the forward link to perform a precoding operation to match the channel so that the information in the channel obtains a large gain in the transmission.

 The codebook includes a plurality of codewords, and the plurality of codewords are a matrix for quantizing a variation between a main feature matrix of the channel matrix and the first reference matrix, the main feature matrix The effective channel information required for calculating the precoding matrix for the link receiving end.

According to the channel information feedback system provided by the embodiment of the present invention, the transmitting end of the feedback link selects the first codeword from the preset codebook according to the channel matrix and the first reference matrix and the first The sequence number of the codeword is sent to the receiving end of the feedback link to implement feedback of channel information, wherein the codebook includes a plurality of codewords, and the codeword is a main feature matrix for quantifying the channel matrix and the first a matrix of the amount of change between reference matrices, the main feature matrix is effective channel information required for calculating a precoding matrix by the link receiving end; by using a main feature matrix as a feedback object, since the main feature matrix is a feedback The link receiving end calculates the effective channel information required by the precoding matrix, that is, the minimum channel information required by the receiving end of the feedback link to calculate the precoding matrix, so that the feedback amount can be reduced from the source, and the main feature matrix is quantized by feedback. The codeword with the amount of change between the reference feature space belongs to differential feedback, and in a general low-speed moving work scene, there is strong time correlation, and differential feedback can fully satisfy such temporal redundancy information, further Reduce the amount of feedback, the codeword is used to quantify the feedback amount, and the smaller the feedback amount, the higher the feedback accuracy, thus achieving High feedback accuracy. The method, device and system for channel information feedback provided by the embodiments of the present invention can be applied to scenarios with slow channel changes, such as wireless channels, channels on adjacent subcarriers in a MIMO-OFDM system, and the like.

 A person skilled in the art can understand that all or part of the steps of implementing the above embodiments can be completed by a program to instruct related hardware, and the program can be stored in a computer readable storage medium, such as ROM/RAM, magnetic. Disc or CD.

 The above is only the specific embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily think of changes or substitutions within the technical scope of the present invention. It should be covered by the scope of the present invention. Therefore, the scope of the invention should be determined by the scope of the appended claims.

Claims

Rights request

 A method for channel information feedback, comprising:

 The feedback link sender acquires a channel matrix;

 The transmitting end of the feedback link selects a first codeword from the codebook according to the channel matrix and the first reference matrix, where the codebook includes a plurality of codewords arranged by a sequence number, and the plurality of codewords are quantized a matrix of the amount of change between the main feature matrix of the channel matrix and the first reference matrix; the feedback link transmitting end sends the sequence number of the first codeword to the feedback link receiving end.

2. The method according to claim 1, further comprising:

 If the channel information is fed back at the initial time, the link feedback sender acquires the same 酉 matrix as the main feature matrix row number of the channel matrix, and selects the M column from the 酉 matrix to be set to the first a reference matrix, the M column is the number of columns of the main feature matrix of the channel matrix; if the channel information feedback is not at the initial time, the first codeword of the feedback link transmitting end according to the last channel information feedback And the reference matrix when the channel information is fed back last time generates the first reference matrix.

 The method according to claim 2, wherein the feedback link transmitting end generates a location according to the first codeword when the last channel information is fed back and the reference matrix when the last channel information is fed back The first reference matrix is implemented by the following formula:

 (7(0 = qrd{(j{t - 1) + Oiit - ^)D(t - 1)} where:

 ΰ (ή is the first reference matrix;

 Γί {·} is the g ? decomposition operator;

 ϋ(ί - 1) is a reference matrix when the last channel information is fed back;

 丄 -1) is an orthogonal complement matrix of the reference matrix when the last channel information is fed back;

D(t _1 1) is the first codeword when the last channel information is fed back.

The method according to any one of claims 1 to 3, characterized in that Selecting the first codeword from the codebook by using the channel matrix and the first reference matrix, including: according to the channel matrix and the first reference matrix, using a maximum power gain as a standard from the code The first codeword is selected from the codebook, or the first codeword is selected from the codebook by using a minimum matrix distance as a criterion.

 The method according to claim 4, wherein the selecting the first codeword from the codebook according to the channel matrix and the first reference matrix, using a maximum power gain as a standard , by the following formula:

D{t) = arg max H(t) » qrd{U(t) + i) ₁ ( ^t )C}

 Ce codebook F

 among them,

 DO) is the first codeword; arg max || ||^ is a codeword used for selecting the maximum power gain from the codebook;

 Codebook

 O) is the channel matrix;

 Γί {·} is the g ? decomposition operator;

 Is the first reference matrix;

 ϋ At, an orthogonal complement matrix of the first reference matrix;

 c is a codeword in the codebook.

 The method according to claim 4, wherein the selecting the first codeword from the codebook according to the channel matrix and the first reference matrix, using a minimum matrix distance as a criterion , by the following formula:

 D(t) = arg min^(^ (0 , qrd{0 (t) + (j i ( )C})

 Ce codebook

 among them,

 DO) is the first codeword;

Arg _c m _e code in this ^O is the distance between the codebook and the main feature matrix of the channel matrix Codewords used by small ones;

 d(-) is the distance operator between matrices;

 Γί {·} is the g ? decomposition operator;

 a main feature matrix of the channel matrix;

 Is the first reference matrix;

 ϋ At, an orthogonal complement matrix of the first reference matrix;

 c is a codeword in the codebook.

 7. A method for channel information feedback, comprising:

 The receiving end of the feedback link receives the sequence number of the first codeword sent by the sending end of the feedback link; the receiving end of the feedback link selects the first codeword from the codebook according to the sequence number of the first codeword, The codebook includes a plurality of codewords arranged by a sequence number, and the plurality of codewords are a matrix of a variation amount between a main feature matrix of the quantization channel matrix and the first reference matrix.

 The feedback link receiving end generates a second reference matrix according to the first codeword and the first reference matrix.

 8. The method according to claim 7, further comprising:

 If the channel information is fed back at the initial time, the feedback link receiving end acquires the same 酉 matrix as the main feature matrix row number of the channel matrix, and selects the M column from the 酉 matrix to be set as the first reference. a matrix, the M columns being the number of columns of the main feature matrix of the channel matrix; if the channel information feedback is not at an initial time, the feedback link receiving end uses the second reference matrix generated when the last channel information is fed back The first reference matrix.

 The method according to claim 7 or 8, wherein the generating the second reference matrix according to the first codeword and the first reference matrix is specifically implemented by using the following formula:

 U(t + 1) = qrd{U(t) + U{t)D{t)}

among them: U(t + \) is the second reference matrix;

 Γί {·} is a g decomposition operator; is the first reference matrix; 丄 0) is an orthogonal complement matrix of the first reference matrix;

 DO) is the first codeword.

 10. A feedback link transmitting end, comprising:

 An obtaining unit, configured to acquire a channel matrix;

 a first selecting unit, configured to select a first codeword from the codebook according to the channel matrix and the first reference matrix, where the codebook includes a plurality of codewords arranged according to a sequence number, where the plurality of codewords are quantized a matrix of the amount of change between the main feature matrix of the channel matrix and the first reference matrix; the first sending unit, configured to send the sequence number of the first codeword selected by the first selecting unit to the feedback link for receiving end.

 The feedback link transmitting end according to claim 10, further comprising: a first setting unit, configured to acquire a main feature matrix of the channel matrix if the channel information is fed back at an initial time a unitary matrix having the same number of rows, a row selected from the matrix of the matrix is set as the first reference matrix, and the array is a number of columns of a main feature matrix of the channel matrix; When the channel information feedback is not at the initial time, the first reference matrix is generated according to the first codeword when the channel information is fed back and the reference matrix when the channel information is fed back.

 The feedback link transmitting end according to claim 11, wherein the first generating unit is based on the first codeword when the last channel information is fed back and the last channel information feedback The reference matrix is used to generate the first reference matrix, which is implemented by the following formula: ϋ(ί) = qrd{(j{t - 1) + Oiit - ^)D(t - 1)}

 among them:

ΰ (ή is the first reference matrix; Γί {·} is the g ? decomposition operator;

 ϋ(ί - 1) is a reference matrix when the last channel information is fed back;

 丄 -1) is an orthogonal complement matrix of the reference matrix when the last channel information is fed back;

D(t _1 1) is the first codeword when the last channel information is fed back.

 The feedback link transmitting end according to any one of claims 10 to 12, wherein the first selecting unit comprises:

 a first selecting subunit, configured to select the first codeword from the codebook according to the channel matrix and the first reference matrix, using a maximum power gain as a criterion; and/or

 a second selecting subunit, configured to select the first codeword from the codebook according to the channel matrix and the first reference matrix, using a minimum matrix distance as a criterion.

The feedback link transmitting end according to claim 13, wherein the first selecting subunit is configured to: according to the channel matrix and the first reference matrix, use a maximum power gain as a standard The first codeword is selected from the codebook and is implemented by the following formula: (/ ¹ ) = argmax H{t) * qrd{U{t) + ut)C)

 Ce codebook \F where,

 DO) is the first codeword; arg max || ||^ is a codeword used for selecting the maximum power gain from the codebook;

 Codebook O) is the channel matrix;

 Γί {·} is the g ? decomposition operator;

 Is the first reference matrix;

 ϋ At, an orthogonal complement matrix of the first reference matrix;

 c is a codeword in the codebook.

The method according to claim 13, wherein the second selecting subunit is configured to use, according to the channel matrix and the first reference matrix, a minimum matrix distance as a standard Selecting the first codeword from the codebook is implemented by the following formula:

 D(t) = arg min^(^ (0 , qrd{0 (t) + (j i ( )C})

 Ce codebook

 among them,

 DO) is the first codeword;

The arg _c m _e code in this ^O is a codeword used from the codebook to select a matrix having the smallest distance from the main feature matrix of the channel matrix;

 d(-) is the distance operator between matrices;

 Γί {·} is the g ? decomposition operator;

 a main feature matrix of the channel matrix;

 Is the first reference matrix;

 ϋ At, an orthogonal complement matrix of the first reference matrix;

 c is a codeword in the codebook.

 16. A feedback link receiving end, comprising:

 a first receiving unit, configured to receive a sequence number of the first codeword sent by the sending end of the feedback link, and a second selecting unit, configured to select the first code from the codebook according to the sequence number of the first codeword a code, the codebook includes a plurality of codewords arranged by a sequence number, and the plurality of codewords are a matrix of a quantity of change between a main feature matrix of the quantization channel matrix and the first reference matrix;

 a second generating unit, configured to generate a second reference matrix according to the first codeword selected by the second selecting unit and the first reference matrix.

 The feedback link receiving end according to claim 16, further comprising: a second setting unit, configured to acquire a number of main feature matrix rows of the channel matrix if the channel feedback is at an initial time The same 酉 matrix, the M columns are selected from the 酉 matrix as the first reference matrix, and the M columns are the number of columns of the main feature matrix of the channel matrix;

The third setting unit is configured to: when the channel information feedback is not at the initial time, the generated second reference matrix when the channel information is fed back is used as the first reference matrix.

The feedback link receiving end according to claim 16 or 17, wherein the second generating unit is configured to generate, according to the first codeword selected by the second selecting unit and the first reference matrix The second reference matrix is implemented by the following formula:

 U(t + 1) = qrd{U(t) + U{t)D{t)}

 among them:

 V{t + \) is the second reference matrix;

 Γί {·} is a g ? decomposition operator; is the first reference matrix;

 U^t) is an orthogonal complement matrix of the first reference matrix;

 Is the first codeword.

 19. A communication system, comprising:

 a feedback link transmitting end, configured to acquire a channel matrix, select a first codeword from the codebook according to the channel matrix and the first reference matrix, and send the sequence number of the first codeword to a feedback link receiving end;

 a feedback link receiving end, configured to receive a sequence number of the first codeword sent by the sending end of the feedback link, and select the first codeword from the codebook according to the sequence number of the first codeword, according to the first Generating a second reference matrix by a codeword and a first reference matrix;

 The codebook includes a plurality of codewords arranged by a sequence number, and the plurality of codewords are a matrix for quantizing a variation between a main feature matrix of the channel matrix and the first reference matrix.