CN101436890A - Method and equipment for estimating antenna array error parameter - Google Patents

Abstract

The embodiment of the invention discloses a method for estimating an error parameter of an antenna array, which comprises the following steps: sampling incoming wave direction signals on the antenna array for many times, and calculating the number of users by using correlation matrix according to the incoming wave direction signals; judging whether the number of the users is less than or equal to 3; when judging out that the number of the users in a target cell is less than or equal to 3, using the correlation matrix to obtain a characteristic vector corresponding to the number of the users; obtaining a frequency estimation value on the antenna array according to the obtained characteristic vector and a sampling interval; obtaining an array manifold of the antenna array according to the frequency estimation value and the correlation matrix; and calculating the error parameter of the array according to the array manifold of the antenna array. The embodiment of the invention also discloses a device, and provides a method and correction for parameter estimation.

Description

A kind of antenna array error method for parameter estimation and equipment thereof

Technical field

The present invention relates to communication field, relate in particular to a kind of antenna array error method for parameter estimation and equipment thereof.

Background technology

In wireless communication system, more and more general by certain regularly arranged aerial array that forms by a plurality of antennas.By adopting advanced signal processing method, multiaerial system is compared with the conventional single-antenna system, at double the elevator system capacity.Simultaneously, based on the intelligent antenna technology of aerial array, can the estimating user signal with respect to the direction (be arrival bearing) of array on horizontal plane, the wave beam that the forms concentration of energy then user that aims at the mark.Compare with the spherical wave of a single aerial system, significantly enlarged the coverage of base station.

The use of aerial array makes a subscriber signal have a plurality of received signals, i.e. corresponding one tunnel received signal of each array element (unit of aerial array).The difference of different array element received signals can be described with array manifold, and for the aerial array that N array element is arranged, its array manifold is N * 1 vector.The value of its element has been described the difference of different array elements to the same subscriber signal response.Array manifold is determined by the direction of subscriber signal fully in theory.In fact in the use of aerial array, there are many uncertain factors, (as linear array, require array element equidistantly to distribute as the element position deviation, making part array element depart from its position for some reason causes spacing unequal, then claim array element location deviation), array element (vertically places as requiring array element towards deviation, offset from perpendicular then claims array element to exist towards deviation for some reason) etc.These deviations will influence array actual array stream shape, make theoretical array manifold and actual array stream shape difference occur.Key technology in the smart antenna: beam forming (BF:BeamForming) and arrival bearing (DOA:Directionalof Arricial) estimate, all substantial connection is arranged with display stream shape, the error of array manifold will cause the remarkable decline of intelligent antenna performance, therefore, the estimation and the correction of aerial array array element difference are one of key technologies that realizes smart antenna.

Array element difference in the aerial array is called the relative error of aerial array again, and the estimation and the correction of these errors had two class algorithms of different: 1) based on the correcting algorithm of reference signal; 2) school for the blind's normal operation method.

Preceding a kind of method is utilized the known correction signal source of one or more directions, launches correction signal one by one, measures the received signal of each array element simultaneously, by the known source signal and the comparison of received signal, estimates that the various errors of array element are also proofreaied and correct.School for the blind's normal operation method does not need reference signal, is that 02112322.5 patent application (blind correction method of adaptive array antenna and device) is just being mentioned school for the blind in China Patent No..Though the method that this patent provided does not need reference signal, need reference channel that the user is sent signal and deliver to the base station receiving terminal, in fact quite produce a reference signal at the base station end.

But this school for the blind is just needing reference channel will send signal is transferred to the base station end, and needs to estimate that the delay inequality of reference channel and actual channel, reality also are equivalent to produce a reference signal at receiving terminal, and system complexity is higher.

Summary of the invention

In view of the deficiencies in the prior art, the embodiment of the invention has proposed a kind of antenna array error method for parameter estimation and equipment thereof, is just obtaining the antenna array error reference data by school for the blind.

The embodiment of the invention discloses a kind of antenna array error parameter estimation method, comprising:

Repeatedly sample arrival bearing's signal on the aerial array utilizes correlation matrix to calculate number of users according to described arrival bearing's signal;

Judge that whether described number of users is smaller or equal to 3;

When the number of users of judging described Target cell smaller or equal to 3 the time, utilize correlation matrix to obtain the pairing characteristic vector of described number of users;

Obtain frequency estimation on the aerial array according to the characteristic vector of described acquisition and sampling interval;

Array manifold according to described frequency estimation and correlation matrix acquisition aerial array;

Error parameter according to the array manifold computing array of described aerial array.

Accordingly, the embodiment of the invention also discloses a kind of equipment of antenna array error parameter Estimation, comprising:

The number of users estimation unit, the arrival bearing's signal on the aerial array that is used for repeatedly sampling utilizes correlation computations to calculate number of users according to described arrival bearing's signal;

The Frequency Estimation value cell, be used for described number of users estimation unit estimate when the number of users of judging described Target cell smaller or equal to 3 the time, utilize correlation matrix to obtain the pairing characteristic vector of described number of users, and obtain frequency estimation on the aerial array according to the characteristic vector of described acquisition and sampling interval;

The error parameter unit is used for obtaining according to described frequency estimation and correlation matrix the array manifold of aerial array, and according to the error parameter of the array manifold computing array of described aerial array.

The embodiment of the invention provides a kind of antenna array error parameter estimation method: need not transmitting terminal and send reference signal, also need not to produce reference signal at receiving terminal, simplify hardware system, and reduced the interference to proper communication.

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 antenna array error method of estimation in the embodiment of the invention;

Fig. 2 is the structural representation of the antenna array error estimating apparatus in the embodiment of the invention.

Embodiment

The embodiment of the invention is only considered the relative error of aerial array, and relative error refers to the difference that exists between the array element, the difference of every index of absolute error aerial array and ideal design index.The The perfect Gain of for example supposing Antenna Design is 1, if the gain of each array element all is 0.8, then claim aerial array not have relative error (array element does not have difference each other), but exist absolute error (having difference) can reach the purpose of array calibration to the estimation of aerial array absolute error and compensation with desirable index, also can reach the purpose of array calibration to the estimation of its relative error and compensation, after relative error was proofreaied and correct, identical error appearred in whole array.In fact this error can of equal value regard the unknown decay of wireless channel transmission as, can estimate in the subsequent treatment of receiving terminal, and the wave beam that can not influence in the smart antenna forms and arrival bearing's assessment function.Based on above consideration, patent of the present invention is only considered the estimation and the correction of relative error.

The embodiment of the invention provides the estimation error of aerial array and has proofreaied and correct two key steps, because adopt the positive technology of school for the blind, arrival bearing's user the unknown.When number of users more for a long time, may reduce the accuracy of estimation error on the contrary.The element number of array of TD-SCDMA system antenna array is generally 6, is that example describes with 6 array elements mainly in the embodiment of the invention, and the aerial array for other element number of array is suitable for too certainly., make its ability of distinguishing different arrival bearings have restriction, when arrival bearing user more for a long time, the accuracy of distinguishing different directions descends.Therefore, a number of users estimation module of the present invention sampling is estimated the number of users of current area, when determining number of users when being less than or equal to 3, just starts the estimation error step, reaches estimation error and correcting feature preferably with assurance.

The realization of this method can be used as pure software and is embedded in the base station equipment, is inserted in the signal processing flow before the DOA algorithm, and error is estimated and proofreaied and correct.Also can intercept out, handle with separate equipment, as the real-time monitoring system of antenna array error by radio frequency or intermediate-freuqncy signal with the base station.The basic procedure of this method is as follows: when determining the Target cell number of users when being less than or equal to 3, startup is estimated the error on the aerial array, its estimated result is used for the correction of received signal always then, be less than or equal at 3 o'clock up to determine number of users next time, again carrying out array error estimates, and new estimated result is used for the correction of received signal, constantly repeat this process.

Particularly, array error parameter Estimation provided by the present invention and aerial array blind correction method comprise following 5 steps: 1) number of users is estimated; 2) user reaches the signal(-) carrier frequency estimation; 3) the subscriber signal array manifold is estimated; 4) arrival bearing user and array error unites estimation; 5) based on the signal correction of array error estimated result.Wherein have only when estimating that active user's number is less than or equal to 3, just start the user and reach signal(-) carrier frequency and estimate, the subscriber signal array manifold estimate and arrival bearing user and array error unite estimation, concrete steps are as follows:

Step S101: number of users is estimated;

A) by two reception data matrixes with time difference of received signal structure, concrete grammar is as follows: suppose X1 (t), X2 (t), X3 (t), X4 (t), X5 (t), X6 (t) represents the induced signal of each array element respectively, it is carried out uniform sampling obtain discrete signal X1 (n), X2 (n), X3 (n), X4 (n), X5 (n), X6 (n).Data that array element length is N of storage in equipment, and form delegation, as the behavior X1 (0) of first array element, X1 (1), X1 (2) ..., X1 (N-1).The row of 6 array elements is gathered into folds from top to bottom, obtain a data matrix, as follows,

X1(0)X1(1)X1(2)...X1(N-1)

X2(0)X2(1)X2(2)...X2(N-1)

X3(0)X3(1)X3(2)...X3(N-1)

X4(0)X4(1)X4(2)...X4(N-1)

X5(0)X5(1)X5(2)...X5(N-1)

X6(0)X6(1)X6(2)...X6(N-1)

Remove last row of above-mentioned matrix, obtain receiving data matrix 1, remove first row of matrix, obtain receiving data matrix 2, described reception data matrix 1 receives data matrix 2 and forms described reception data matrix with time difference.

B) described reception data matrix with time difference is folded up and down mutually, is obtained following new matrix,

X1(0)X1(1)X1(2)...X1(N-2)

X2(0)X2(1)X2(2)...X2(N-2)

X3(0)X3(1)X3(2)...X3(N-2)

X4(0)X4(1)X4(2)...X4(N-2)

X5(0)X5(1)X5(2)...X5(N-2)

X6(0)X6(1)X6(2)...X6(N-2)

X1(1)X1(2)X1(3)...X1(N-1)

X2(1)X2(2)X2(3)...X2(N-1)

X3(1)X3(2)X3(3)...X3(N-1)

X4(1)X4(2)X4(3)...X4(N-1)

X5(1)X5(2)X5(3)...X5(N-1)

X6(1)X6(2)X6(3)...X6(N-1)

New matrix and its associate matrix multiply each other, and obtain correlation matrix.

C) correlation matrix is carried out characteristic value decomposition, characteristic value is sorted from big to small, the position that detected characteristics value size is undergone mutation, the value of this position correspondence is the incoming wave number, is designated as the estimated result of K as number of users.

Need to prove, when the numerical value that estimates number of users smaller or equal to 3 the time, carrying out step S102.

Step S102: the user reaches signal(-) carrier frequency and estimates;

(1) from aforesaid characteristic value decomposition result, gets K eigenvalue of maximum characteristic of correspondence vector.

(2) described characteristic vector is from left to right rearranged a data matrix.With described matrix decomposition is the submatrix of two non-overlapping copies, and its method is: the first half of submatrix 1 aforementioned matrix, submatrix 2 comprises the Lower Half of aforementioned matrix.

(3) in aforesaid two submatrixs, the generalized inverse matrix of calculated sub-matrix 2 multiply by submatrix 1, obtains the new data matrix.Described new data matrix is carried out characteristic value decomposition one time.The phase value of characteristic value is divided by the sampling interval, and the value that obtains is as the Frequency Estimation result.

Step S103: the subscriber signal array manifold is estimated;

A, according to the Frequency Estimation result, the filtering to received signal of design different band bandpass filter, the building method of band pass filter is as follows: the centre frequency of all band pass filters is the estimated result of described Frequency Estimation, and the passband width of all band pass filters is the signal frequency width of TD-SCDMA system defined.

B, band pass filter is acted on received signal, to the output of each band pass filter, the value of each sampling instant is formed row, and these row are from left to right arranged in chronological order, form a data matrix.Described data matrix and its associate matrix are multiplied each other, obtain correlation matrix.

C, described correlation matrix is carried out characteristic value decomposition, characteristic value is sorted from big to small, the position that detected characteristics value size is undergone mutation, the value of this position correspondence is the incoming wave number that current carrier wave comprised, and is designated as K _i

D, from aforesaid characteristic value decomposition result, get K _iIndividual eigenvalue of maximum characteristic of correspondence vector is as the estimation of user array stream shape.

Aforesaid arrival bearing and array error combined estimation method, its employed criterion are that array error and arrival bearing are constructed desirable array manifold as unknown parameter, and make it as far as possible near aforesaid array manifold estimated result.

Step S104: arrival bearing and array error are united estimation:

A) initial estimate that array amplitude response sum of errors array phase response error is set is 0.

B) based on current array amplitude response sum of errors array phase response error estimated value, utilize above-mentioned criterion to estimate the arrival bearing of all incoming waves.Suppose

Expression estimates that by above-mentioned array manifold estimation module the user array that obtains flows shape,

The array flow pattern that expression is made of error parameter and unknown arrival bearing makes

With

Approaching as far as possible concrete mode is the angle that minimizes between them, and is as follows:

$\min \frac{\left|\right|\stackrel{\→}{a}\stackrel{\→}{b}\left|\right|}{\left|\right|\stackrel{\→}{a}\left|\right|\left|\right|\stackrel{\→}{b}\left|\right|}$

C), utilize aforementioned criteria to reappraise array amplitude response sum of errors array phase response error based on aforementioned arrival bearing's estimated result;

D) repeating step B) and C) there is not significant difference at twice adjacent estimated result up to array amplitude response and array phase response.

Step S104: proofread and correct to received signal.

Concrete, contrary by the evaluated error instrument error multiply by received signal, and the signal that obtains is correction signal.

Accordingly, Fig. 2 shows the structural representation of the antenna array error parameter Estimation equipment in the embodiment of the invention, comprising:

Number of users estimation unit 201, the arrival bearing's signal on the aerial array that is used for repeatedly sampling utilizes correlation computations to calculate number of users according to described arrival bearing's signal;

Concrete, the pairing induced signal of each array element on the sampling aerial array, and the induced signal of described each sampling is carried out uniform sampling obtain discrete signal; Row with the pairing discrete signal composition data of each array element matrix; Remove last row in the described data matrix, obtain first data matrix; Remove the row of first in the described data matrix, obtain second data matrix; First data matrix is folded mutually up and down with second data matrix, obtain the 3rd data matrix; The associate matrix of the 3rd data matrix and described the 3rd data matrix is multiplied each other, obtain first correlation matrix; Described first correlation matrix is carried out characteristic value decomposition, the characteristic value that is sorted from big to small; The position that detected characteristics value size is undergone mutation, the pairing value in the position of described sudden change is a number of users.

Frequency Estimation value cell 202, be used for described number of users estimation unit 201 estimate when the number of users of judging described Target cell smaller or equal to 3 the time, utilize correlation matrix to obtain the pairing characteristic vector of described number of users, and obtain frequency estimation on the aerial array according to the characteristic vector of described acquisition and sampling interval.

Concrete, the pairing characteristic vector of described acquisition is rearranged the 4th data matrix, and described the 4th data matrix resolved into the 5th data matrix and the 6th data matrix, wherein: described the 5th data matrix is the first half of the 4th data matrix, and described the 6th data matrix is the Lower Half of the 4th data matrix; Calculate the generalized inverse matrix of the 6th data matrix, multiply by the 5th data matrix and obtain the 7th data matrix; Described the 7th data matrix is carried out characteristic value decomposition, and the phase value that described the 7th data matrix is carried out the characteristic value after the characteristic value decomposition obtains frequency estimation on the aerial array divided by the sampling interval.

Error parameter unit 203 is used for obtaining according to described frequency estimation and correlation matrix the array manifold of aerial array, and according to the error parameter of the array manifold computing array of described aerial array.

Concrete, arrival bearing's signal of described sampling is exported by band pass filter, obtain the 8th data matrix; Obtain second correlation matrix by described the 8th data matrix, described second correlation matrix is carried out characteristic value decomposition, the position that detected characteristics value size is undergone mutation, described position are the incoming wave number that current carrier wave comprised; From described second correlation matrix carry out after the characteristic value decomposition obtain the incoming wave number the pairing characteristic vector of eigenvalue of maximum of corresponding number.

Accordingly, this equipment also comprises correcting unit 204, is used for after described error parameter unit calculates error parameter described received signal being proofreaied and correct.

To sum up, the embodiment of the invention provides a kind of antenna array error parameter estimation method: need not transmitting terminal and send reference signal, also need not to produce reference signal at receiving terminal, simplify hardware system, and reduced the interference to proper communication.

Above disclosed is a kind of preferred embodiment of the present invention only, can not limit the present invention's interest field certainly with this, and therefore the equivalent variations of doing according to claim of the present invention still belongs to the scope that the present invention is contained.

Through the above description of the embodiments, those skilled in the art can be well understood to the present invention and can realize by the mode that software adds essential hardware platform, can certainly all implement by hardware.Based on such understanding, all or part of can the embodying that technical scheme of the present invention contributes to background technology with the form of software product, this computer software product can be stored in the storage medium, as ROM/RAM, magnetic disc, CD etc., comprise that some instructions are with so that a computer equipment (can be a personal computer, server, the perhaps network equipment etc.) carry out the described method of some part of each embodiment of the present invention or embodiment.

Claims (7)

1, a kind of antenna array error parameter estimation method is characterized in that, comprising:

Repeatedly sample arrival bearing's signal on the aerial array utilizes correlation matrix to calculate number of users according to described arrival bearing's signal;

Judge that whether described number of users is smaller or equal to 3;

When the number of users of judging described Target cell smaller or equal to 3 the time, utilize correlation matrix to obtain the pairing characteristic vector of described number of users;

Obtain frequency estimation on the aerial array according to the characteristic vector of described acquisition and sampling interval;

Array manifold according to described frequency estimation and correlation matrix acquisition aerial array;

Error parameter according to the array manifold computing array of described aerial array.

2, the method for claim 1 is characterized in that, the arrival bearing's signal on the described aerial array of repeatedly sampling utilizes correlation matrix to calculate the number of users step according to described arrival bearing's signal and is specially:

The pairing induced signal of each array element on the sampling aerial array, and the induced signal of described each sampling is carried out uniform sampling obtain discrete signal;

Row with the pairing discrete signal composition data of each array element matrix;

Remove last row in the described data matrix, obtain first data matrix;

Remove the row of first in the described data matrix, obtain second data matrix;

First data matrix is folded mutually up and down with second data matrix, obtain the 3rd data matrix;

The associate matrix of the 3rd data matrix and described the 3rd data matrix is multiplied each other, obtain first correlation matrix;

Described first correlation matrix is carried out characteristic value decomposition, the characteristic value that is sorted from big to small;

The position that detected characteristics value size is undergone mutation, the pairing value in the position of described sudden change is a number of users.

3, method as claimed in claim 2 is characterized in that, the described error parameter value step that obtains on the aerial array according to described characteristic vector and sampling interval is specially:

The pairing characteristic vector of described acquisition is rearranged the 4th data matrix, and described the 4th data matrix resolved into the 5th data matrix and the 6th data matrix, wherein: described the 5th data matrix is the first half of the 4th data matrix, and described the 6th data matrix is the Lower Half of the 4th data matrix;

Calculate the generalized inverse matrix of the 6th data matrix, multiply by the 5th data matrix and obtain the 7th data matrix;

Described the 7th data matrix is carried out characteristic value decomposition, and the phase value that described the 7th data matrix is carried out the characteristic value after the characteristic value decomposition obtains frequency estimation on the aerial array divided by the sampling interval.

4, method as claimed in claim 3 is characterized in that, described array manifold step according to described frequency estimation and correlation matrix acquisition aerial array is specially:

Arrival bearing's signal of described sampling is exported by band pass filter, obtained the 8th data matrix;

Obtain second correlation matrix by described the 8th data matrix, described second correlation matrix is carried out characteristic value decomposition, the position that detected characteristics value size is undergone mutation, described position are the incoming wave number that current carrier wave comprised;

From described second correlation matrix carry out after the characteristic value decomposition obtain the incoming wave number the pairing characteristic vector of eigenvalue of maximum of corresponding number.

5, method as claimed in claim 4 is characterized in that, described method also comprises:

After error parameter, described received signal is proofreaied and correct according to the array manifold computing array of described aerial array.

6, a kind of equipment of antenna array error parameter Estimation is characterized in that, comprising:

The number of users estimation unit, the arrival bearing's signal on the aerial array that is used for repeatedly sampling utilizes correlation computations to calculate number of users according to described arrival bearing's signal;

The Frequency Estimation value cell, be used for described number of users estimation unit estimate when the number of users of judging described Target cell smaller or equal to 3 the time, utilize correlation matrix to obtain the pairing characteristic vector of described number of users, and obtain frequency estimation on the aerial array according to the characteristic vector of described acquisition and sampling interval;

The error parameter unit is used for obtaining according to described frequency estimation and correlation matrix the array manifold of aerial array, and according to the error parameter of the array manifold computing array of described aerial array.

7, equipment as claimed in claim is characterized in that, described equipment also comprises correcting unit, is used for after described error parameter unit calculates error parameter described received signal being proofreaied and correct.

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