CN102257778A - Channel quality estimation method, device and wireless receiver - Google Patents

Abstract

The invention discloses a channel quality estimation method, a device and a wireless receiver, referring to the wireless communication technical field and solves the problem in existing channel quality estimation methods that calculated effective signal-noise ratio is not accurate, which causes the inaccuracy of the channel quality estimation. In the embodiment of the invention, in a process of calculating an equilibrium matrix, a sum of a channel matrix and an estimation difference of the channel matrix, i.e.,a channel estimation matrix is employed such that the effective signal-noise ratio by employing the equilibrium matrix is more accurate and thereby the accuracy of the channel quality estimation. The embodiment of the invention is mainly applied on occasions of single data flow sending and multi-receiving antenna in a wireless communication system.

Description

Channel quality estimation method, device and wireless receiver

Technical field

The present invention relates to wireless communication technology field, relate in particular to channel quality estimation method, device and wireless receiver.

Background technology

At radio MIMO (Multiple-Input Multiple-Output, multiple-input and multiple-output) in the communication system, often need be to effective Signal to Interference plus Noise Ratio (Signal to Interference plus Noise Ratio of wireless environment, abbreviate as: SINR) estimate to understand channel quality and to utilize this information to improve power system capacity, such as: signal receiving end obtains CQI (Channel Quality Indication by estimating effective Signal to Interference plus Noise Ratio and then estimation, channel quality is indicated) and PMI (Precoding Matrix Index, pre-coding matrix index), then CQI and PMI are fed back to signal sending end, select to be fit to the modulating-coding pattern of current channel transfer characteristic and carry out wave beam forming with the index signal transmitting terminal, thereby improve power system capacity at signal sending end.

The effective signal to noise ratio of SINR after the equilibrium of wireless MIMO communication system middle finger, this parameter can reflect receiver performance.Transmitting terminal at radio MIMO system adopts single data stream to send data, receiving terminal disturbs the scene that suppresses to merge (Interference Rejection Combining) to the received signal of a plurality of antennas, and the computational methods of existing effective SINR comprise: calculate according to selected system estimation criterion, ideal communication channel matrix and interference correlation matrix and obtain balanced matrix; According to signal after balanced front signal that receives from reception antenna and the balanced matrix computations equilibrium; According to the effective SINR of calculated signals after this equilibrium.

In the process of the effective SINR of aforementioned calculation, the inventor finds that there are the following problems at least in the prior art: used the ideal communication channel matrix when calculating balanced matrix, but this matrix the unknown in the actual moving process of communication system, must rely on and estimate just can obtain (being channel estimate matrix), because channel matrix that this estimation obtains and ideal communication channel matrix can not be in full accord, afterwards signal is inaccurate to cause calculating equilibrium with this equilibrium matrix, thereby can't obtain effective accurately SINR, and then have influence on the accuracy of channel quality estimation, cause receiving terminal can't utilize effective SINR to improve power system capacity, may reduce power system capacity on the contrary.

Summary of the invention

Embodiments of the invention provide a kind of channel quality estimation method, device and wireless receiver, can obtain accurately effectively SINR, and then can improve the accuracy of channel quality estimation.

For achieving the above object, embodiments of the invention adopt following technical scheme:

A kind of channel quality estimation method comprises: with channel matrix

And this channel matrix

Evaluated error

Addition obtains balanced matrix G; According to the balanced front signal that receives from reception antenna

And described balanced matrix G calculates the effective Signal to Interference plus Noise Ratio that is used for estimated channel quality.

A kind of channel quality estimation device comprises: computing module is used for channel matrix

And this channel matrix

Evaluated error

Addition obtains balanced matrix G; Quality assessment modules is used for the balanced front signal that receives according to from reception antenna

And described balanced matrix G calculates the effective Signal to Interference plus Noise Ratio that is used for estimated channel quality.

The embodiment of the invention also provides a kind of wireless receiver that comprises described channel quality estimation device.

In the channel quality estimation method that the embodiment of the invention provides, device and the wireless receiver, when calculating balanced matrix, evaluated error sum by channel matrix and this channel matrix obtains channel estimate matrix, owing to taken into full account of the influence of the error component of channel matrix to channel quality estimation, make that the effective SINR accuracy that adopts this equilibrium matrix computations to obtain is higher, thereby improved the accuracy of channel quality estimation.

Description of drawings

In order to be illustrated more clearly in the embodiment of the invention or technical scheme of the prior art, to do to introduce simply to the accompanying drawing of required use in embodiment or the description of the Prior Art below, apparently, accompanying drawing in describing below only is some embodiments of the present invention, for those of ordinary skills, under the prerequisite of not paying creative work, can also obtain other accompanying drawing according to these accompanying drawings.

Fig. 1 is the flow chart of the channel quality estimation method of the embodiment of the invention 1;

Fig. 2 is the block diagram of the channel quality estimation device of the embodiment of the invention 1;

Fig. 3 is the block diagram of the channel quality estimation device of the embodiment of the invention 3.

Embodiment

Below in conjunction with the accompanying drawing in the embodiment of the invention, the technical scheme in the embodiment of the invention is clearly and completely described, obviously, described embodiment only is the present invention's part embodiment, rather than whole embodiment.Based on the embodiment among the present invention, those of ordinary skills belong to the scope of protection of the invention not making the every other embodiment that is obtained under the creative work prerequisite.

Embodiment 1

Present embodiment provides a kind of channel quality estimation method, can be applicable in the wireless receiver, and as shown in Figure 1, this method comprises the steps.

101, with channel matrix

And this channel matrix Evaluated error

Addition obtains balanced matrix G.

Be specially, when calculating balanced matrix, adopted channel matrix

And this channel matrix

Evaluated error

Sum has promptly been introduced the evaluated error of channel matrix

This evaluated error

With channel matrix

Sum has been described the estimated value of channel matrix exactly, makes the balanced matrix G that calculates acquisition to the signal that receives from reception antenna better portfolio effect be arranged.

102, according to the balanced front signal that receives from reception antenna And described balanced matrix G calculates the effective Signal to Interference plus Noise Ratio that is used for estimated channel quality.

Particularly, use the balanced front signal of balanced matrix G that calculates acquisition by step 101 to receiving from reception antenna

After carrying out equilibrium and calculating, can obtain the signal after the equilibrium.Can calculate according to the signal after this equilibrium again and obtain effective Signal to Interference plus Noise Ratio.

In the present embodiment because when calculating balanced matrix, adopted the evaluated error sum of channel matrix and this channel matrix, should and be channel estimate matrix, make that the effective SINR accuracy that adopts this equilibrium matrix computations to obtain is higher, thereby improved the accuracy of channel quality estimation.

Present embodiment also provides a kind of channel quality estimation device, and as shown in Figure 2, this device comprises: computing module 21 is used for channel matrix

And this channel matrix

Evaluated error

Addition obtains balanced matrix G; Quality assessment modules 22 is used for the balanced front signal that receives according to from reception antenna

Reach described balanced matrix G and calculate the effective Signal to Interference plus Noise Ratio that is used for estimated channel quality, to estimate quality of channel.Computing module 21 and quality assessment modules 22 can be realized by hardware, can be respectively processors for example.

The performed method of each module describes in detail in above-mentioned channel quality estimation method in the above-mentioned channel quality estimation device, does not repeat them here.

In the channel quality estimation device that present embodiment provides, because when adopting computing module to calculate balanced matrix, adopted the evaluated error sum of channel matrix and this channel matrix, should and be channel estimate matrix, make that the effective SINR accuracy that adopts this equilibrium matrix computations to obtain is higher, thereby improved the accuracy of channel quality estimation.

Embodiment 2

Present embodiment provides a kind of channel quality estimation method, and this method is applied in the scene of single data stream transmission, multiple receive antenna, and this method comprises the steps.

Step 1, according to channel matrix

And evaluated error

Sum calculates balanced matrix G.

Wherein, balanced matrix G can be according to formula

Calculate to obtain, a is the constant greater than 0, according to the difference of the system estimation criterion that is adopted and difference, Be interference correlation matrix.

Balanced matrix computing formula with prior art

Compare, present embodiment has been introduced the evaluated error of channel matrix in the computational process of balanced matrix G

This estimates mistake

Described the estimated value of channel matrix exactly with the channel matrix sum, made and calculate the balanced matrix that obtains the signal that receives from reception antenna is had better portfolio effect.

When the hypothesis channel matrix be estimated as Linear Estimation, and estimation coefficient carried out normalization, and supposes constant a=1 in the balanced matrix computing formula, the then evaluated error of channel matrix Computing formula can for

Wherein, W is the estimation coefficient matrix of channel matrix, and dimension is N _R* N, can select for use from the signal that reception antenna receives part signal as treating estimating resource, a bit of time resource or frequency resource near this resource are chosen to be observed quantity, in this section in the observed quantity, can suppose that channel matrix is invariable, suppose that simultaneously interference is uncorrelated between each observed quantity, and the statistical property of each interference signal is identical.N _RBe the number of reception antenna, N is the observed quantity dimension,

For corresponding to interference vector described observed quantity, N dimension.

Element { W} in the estimation coefficient matrix W of channel matrix _IjEstimation coefficient for the channel matrix of different reception antenna correspondences.The estimation coefficient of channel matrix of supposing different reception antenna correspondences is identical, i.e. { W} _Ij={ W} _Mj, i ≠ m, then element { W} _IjCan use w _j, j=1,2 ..., N represents.

Then

Wherein, u ' _{I, j}Interference for corresponding i reception antenna and j observed quantity.Because in the observed quantity dimension, disturb uncorrelatedly between each observed quantity, therefore have:

$E\left(W{\stackrel{\→}{u}}^{\′}{\left(W{\stackrel{\→}{u}}^{\′}\right)}^H\right)=\left(\underset{i=0}{\overset{N-1}{\mathrm{\Σ}}}{w_i}^2\right)R_{\mathrm{uu}}=\mathrm{\β}{R}_{\mathrm{uu}}---\left(1\right)$

In the above-mentioned formula (1),

The conjugate transpose of subscript H representing matrix.

Can obtain the computing formula of balanced matrix G by above-mentioned derivation

The balanced front signal that step 2, basis receive from reception antenna Reach described balanced matrix G and calculate effective Signal to Interference plus Noise Ratio, to estimate quality of channel.

Particularly, can at first pass through formula by the mode of prior art Calculate balanced back signal

Wherein Be balanced front signal.The system model of wireless MIMO communication system is:

Wherein Be channel matrix, in the present embodiment Be N _RThe channel matrix of * 1 dimension.S is the signal that transmitting antenna sends,

Be the interference vector of channel, wherein, corresponding to interference vector observed quantity, the N dimension

Interference vector with channel

Between relation can be formulated as:

Because s is a single data stream, its value is constant.By what will try to achieve before

Substitution

Can obtain balanced back signal Computing formula.Those skilled in the art can finish signal after the equilibrium according to the computational methods of prior art

Find the solution, promptly by balanced back signal

In available signal power find the solution with the ratio of interfering signal power.But, slightly explain finding the solution derivation below for the ease of understanding.

$\hat{s}={(\stackrel{\→}{h}+W{\stackrel{\→}{u}}^{\′})}^H{R}_{\mathrm{uu}}^{-1}(\stackrel{\→}{h}s+\stackrel{\→}{u})={\stackrel{\→}{h}}^H{R}_{\mathrm{uu}}^{-1}\stackrel{\→}{h}s+{\left(W{\stackrel{\→}{u}}^{\′}\right)}^H{R}_{\mathrm{uu}}^{-1}\stackrel{\→}{h}s+{\stackrel{\→}{h}}^H{R}_{\mathrm{uu}}^{-1}\stackrel{\→}{u}+{\left(W{\stackrel{\→}{u}}^{\′}\right)}^H{R}_{\mathrm{uu}}^{-1}\stackrel{\→}{u}---\left(2\right)$

Find out to have only first can think useful signal in the formula (2) easily, other all disturbed pollutions become distracter, establish its performance number according to distracter order from left to right and are respectively I ₁, I ₂, I ₃

The computing formula of signal power P is:

$P={\stackrel{\→}{h}}^H{R}_{\mathrm{uu}}^{-1}\stackrel{\→}{h}\mathrm{ss}*{\stackrel{\→}{h}}^H{R}_{\mathrm{uu}}^{-1}\stackrel{\→}{h}={\left({\stackrel{\→}{h}}^H{R}_{\mathrm{uu}}^{-1}\stackrel{\→}{h}\right)}^2---\left(3\right)$

Interference power I ₁, I ₂, I ₃Computing formula respectively as follows:

$I_1=E({\left(W{\stackrel{\→}{u}}^{\′}\right)}^H{R}_{\mathrm{uu}}^{-1}\stackrel{\→}{h}\mathrm{ss}*{\stackrel{\→}{h}}^H{R}_{\mathrm{uu}}^{-1}\left(W{\stackrel{\→}{u}}^{\′}\right))=\mathrm{trace}\left(E\left({\stackrel{\→}{h}}^H{R}_{\mathrm{uu}}^{-1}\left(W{\stackrel{\→}{u}}^{\′}\right){\left(W{\stackrel{\→}{u}}^{\′}\right)}^H{R}_{\mathrm{uu}}^{-1}\stackrel{\→}{h}\right)\right)=\mathrm{\β}{\stackrel{\→}{h}}^H{R}_{\mathrm{uu}}^{-1}\stackrel{\→}{h}---\left(4\right)$

$I_2=E\left({\stackrel{\→}{h}}^H{R}_{\mathrm{uu}}^{-1}\stackrel{\→}{u}{\stackrel{\→}{u}}^H{R}_{\mathrm{uu}}^{-1}\stackrel{\→}{h}\right)={\stackrel{\→}{h}}^H{R}_{\mathrm{uu}}^{-1}\stackrel{\→}{h}---\left(5\right)$

$I_3=E(\left({\left(W{\stackrel{\→}{u}}^{\′}\right)}^H{R}_{\mathrm{uu}}^{-1}\stackrel{\→}{u}\right)\left({\left(W{\stackrel{\→}{u}}^{\′}\right)}^H{R_{\mathrm{uu}}^{-1}\stackrel{\→}{u})}^H\right)=E\left({\left(W{\stackrel{\→}{u}}^{\′}\right)}^H{R}_{\mathrm{uu}}^{-1}\stackrel{\→}{u}{\stackrel{\→}{u}}^H{R}_{\mathrm{uu}}^{-1}\left(W{\stackrel{\→}{u}}^{\′}\right)\right)=E\left({\left(W{\stackrel{\→}{u}}^{\′}\right)}^H{R}_{\mathrm{uu}}^{-1}\left(W{\stackrel{\→}{u}}^{\′}\right)\right)$

, right Carry out Cholesky and decompose, And bring formula (1) into following formula, then following formula can be rewritten as: $I_3=E\left({\left(\mathrm{LW}{\stackrel{\→}{u}}^{\′}\right)}^H\left(\mathrm{LW}{\stackrel{\→}{u}}^{\′}\right)\right)=\mathrm{trace}\left(\left(\mathrm{LW}{\stackrel{\→}{u}}^{\′}\right){\left(\mathrm{LW}{\stackrel{\→}{u}}^{\′}\right)}^H\right)=\mathrm{trace}\left(\mathrm{\β}{\mathrm{LR}}_{\mathrm{uu}}{L}^H\right)$

$=\mathrm{trace}\left({\mathrm{\βLL}}^{-1}{\left(L^H\right)}^{-1}{L}^H\right)=\mathrm{\β}{N}_R---\left(6\right)$

In the above-mentioned formula (6), trace () asks the mark computing for matrix.

Then according to the effective computing formula of SINR Reach formula (3)～(6), can obtain the Signal to Interference plus Noise Ratio of this communication system, promptly

Effective SINR result that effective SINR result that present embodiment calculates and prior art calculate

Compare and introduced the β item relevant, make that the effective SINR that calculates is more accurate, thereby can estimate quality of channel exactly with evaluated error.

Embodiment 3

Present embodiment provides a kind of channel quality estimation device, can be arranged in wireless receiver, and as shown in Figure 3, this device comprises: computing module 31 can be a processor, is used for channel matrix

And this channel matrix

Evaluated error

Addition obtains balanced matrix G; Quality assessment modules 32 can be another processor, is used for the balanced front signal that receives according to from reception antenna

And described balanced matrix G calculates the effective Signal to Interference plus Noise Ratio that is used for estimated channel quality.

Computing module 31 can comprise first computing unit 311, and this first computing unit 311 can be a processor unit, is used for according to formula

Calculate to obtain described balanced matrix G, wherein, a is the constant greater than 0, according to the difference of the system estimation criterion that is adopted and difference; Be interference correlation matrix.

Computing module also can comprise second computing unit 312, and this second computing unit 312 can be another processor unit, is used to pass through formula

Calculate and obtain described evaluated error

And will calculate

Send to described first computing unit 311; Wherein, W be described channel matrix, N _RThe estimation coefficient matrix of * N dimension, wherein, N _RBe the number of reception antenna, N is the observed quantity dimension;

For corresponding to interference vector described observed quantity, N dimension.

Quality assessment modules 32 can comprise: the 3rd computing unit 321 can be a processor unit, is used for the balanced front signal that receives from reception antenna according to described

And described balanced matrix G calculates balanced back signal

The 4th computing unit 322 also can be a processor unit, is used for according to described balanced back signal

Calculate described effective Signal to Interference plus Noise Ratio.

The performed method of above-mentioned each module is described in detail in embodiment 2, does not repeat them here.Described each the method and apparatus of present embodiment is applied in the MIMO wireless receiver usually, is used to estimate effective Signal to Interference plus Noise Ratio SINR.

In the present embodiment, because when adopting computing module to calculate balanced matrix, adopted the evaluated error sum of channel matrix and this channel matrix, should and be channel estimate matrix, make that the effective SINR accuracy that adopts this equilibrium matrix computations to obtain is higher, thereby improved the accuracy of channel quality estimation.

Through the above description of the embodiments, the those skilled in the art can be well understood to the present invention and can realize by the mode that software adds essential common hardware, can certainly pass through hardware, but the former is better execution mode under a lot of situation.Based on such understanding, the part that technical scheme of the present invention contributes to prior art in essence in other words can embody with the form of software product, this computer software product is stored in the storage medium that can read, floppy disk as computer, hard disk or CD etc., comprise some instructions with so that computer equipment (can be personal computer, server, the perhaps network equipment etc.) carry out the described method of each embodiment of the present invention.

The embodiment of the invention is mainly used in the scene of single data stream transmission, multiple receive antenna in the wireless communication system.

The above; only be the specific embodiment of the present invention, but protection scope of the present invention is not limited thereto, anyly is familiar with those skilled in the art in the technical scope that the present invention discloses; the variation that can expect easily or replacement all should be encompassed within protection scope of the present invention.Therefore, protection scope of the present invention should be as the criterion with the protection range of described claim.

Claims (10)

1. a channel quality estimation method is characterized in that, comprising:

With channel matrix

And this channel matrix

Evaluated error

Addition obtains balanced matrix G;

According to the balanced front signal that receives from reception antenna

And described balanced matrix G calculates the effective Signal to Interference plus Noise Ratio that is used for estimated channel quality.

2. method according to claim 1 is characterized in that, described balanced matrix G is according to formula Calculate acquisition, wherein, a is the constant greater than 0,

Be interference correlation matrix.

3. method according to claim 2 is characterized in that, described evaluated error

By formula

Calculate acquisition, wherein,

W be described channel matrix, N _RThe estimation coefficient matrix of * N dimension, wherein, N _RBe the number of reception antenna, N is the observed quantity dimension;

For corresponding to interference vector described observed quantity, N dimension.

4. according to each described method in the claim 1 to 3, it is characterized in that the balanced front signal that described basis receives from reception antenna

And effective Signal to Interference plus Noise Ratio that described balanced matrix G calculating is used for estimated channel quality comprises:

Based on following formula, according to the described balanced front signal that receives from reception antenna

And described balanced matrix G calculates balanced back signal

$\hat{s}=G\stackrel{\→}{r};$

According to described balanced back signal

Calculate described effective Signal to Interference plus Noise Ratio.

5. method according to claim 4 is characterized in that, described balanced back signal

Comprise:

Useful signal

First distracter

Second distracter

The 3rd distracter

Wherein, s is the signal that transmitting antenna sends,

Interference vector for channel.

6. a channel quality estimation device is characterized in that, comprising:

Computing module is used for channel matrix

And this channel matrix

Evaluated error

Addition obtains balanced matrix G;

Quality assessment modules is used for the balanced front signal that receives according to from reception antenna

And described balanced matrix G calculates the effective Signal to Interference plus Noise Ratio that is used for estimated channel quality.

7. device according to claim 6 is characterized in that described computing module comprises first computing unit, and this first computing unit is used for according to formula

Calculate and obtain described balanced matrix G, wherein, a is the constant greater than 0,

Be interference correlation matrix.

8. device according to claim 7 is characterized in that described computing module also comprises second computing unit, and this second computing unit is used to pass through formula Calculate and obtain described evaluated error

And will calculate

Send to described first computing unit; Wherein,

W be described channel matrix, N _RThe estimation coefficient matrix of * N dimension, wherein, N _RBe the number of reception antenna, N is the observed quantity dimension;

For corresponding to interference vector described observed quantity, N dimension.

9. according to each described device in the claim 6 to 8, it is characterized in that described quality assessment modules comprises:

The 3rd computing unit is used for the balanced front signal that receives from reception antenna according to described

And described balanced matrix G calculates balanced back signal

The 4th computing unit is used for according to described balanced back signal

Calculate described effective Signal to Interference plus Noise Ratio.

10. a wireless receiver is characterized in that, comprises as each described device in the claim 6 to 9.

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