CN105991484A - Frequency offset estimation method and frequency offset estimation device - Google Patents

Abstract

Embodiments of the invention disclose a frequency offset estimation method and a frequency offset estimation device. The method comprises the following steps: carrying out frequency offset estimation according to the repeatability of cyclic prefix CP to get a first frequency offset estimated value; getting at least one second frequency offset estimated value through a preset pilot pair, and getting a wide range of frequency offset estimated values to be chosen according to the at least one second frequency offset estimated value and preset operation rules; and getting an optimal frequency offset estimated value according to the first frequency offset estimated value, the wide range of frequency offset estimated values to be chosen and a preset range value.

Description

The method and apparatus that a kind of frequency deviation is estimated

Technical field

The present invention relates to signal of communication treatment technology, particularly relate to the method and apparatus that a kind of frequency deviation is estimated.

Background technology

OFDM (OFDM, Orthogonal Frequency Division Multiplexing) technology Being the mutually orthogonal Multicarrier Transmission Technology of a sub-carrier, this technology requires between subcarrier mutually orthogonal, And it is very sensitive to carrier frequency shift；So, carrier frequency shift problem becomes current OFDM technology One of key problem.

Currently for the problem that frequency deviation is less, existing a lot of precision are high and realize simple method；But Problem for big frequency deviation, it is common that employing two schemes:

The first, utilize the repeatability of Cyclic Prefix (CP, Cyclic Prefix) to carry out frequency deviation estimation, but Being to utilize CP to carry out the method precision of frequency deviation estimation not, maximum error can reach a few KHz.

The second, utilizes frequency domain Zhong Liangge community own reference signal (CRS, Cell-specific Reference Signals) frequency pilot sign carries out frequency deviation estimation, but the frequency offset estimation range of the method is big not, such as The frequency deviation region obtained (0,7) or (4,11) according to a CRS ordinary symbol is (-1000,1000) Hz, When true frequency deviation value exceedes this scope, it is necessary to by constantly straight to true frequency deviation value plus-minus 2000Hz Scope to result is in (-1000,1000) Hz scope, therefore there will be frequency deviation value on a large scale and is probably 1000Hz, by carrying out the phenomenon that the computing of 1000-2000=-1000Hz occurs in that frequency deviation overturns.

Summary of the invention

For solving above-mentioned technical problem, embodiment of the present invention expectation provides the method and apparatus that a kind of frequency deviation is estimated, For the problem of big frequency deviation, it is not only able to improve frequency offset estimation accuracy, and it can be avoided that occurs that frequency deviation overturns Phenomenon.

The technical scheme is that and be achieved in that:

First aspect, embodiments provides a kind of method that frequency deviation is estimated, described method includes:

Repeatability according to cyclic prefix CP carries out frequency deviation estimation, obtains the first frequency deviation estimated value；

By default pilot tone to obtaining at least one second frequency deviation estimated value, and estimate according to described second frequency deviation Evaluation and the operational rule preset obtain frequency deviation estimated value on a large scale to be selected；

According to described first frequency deviation estimated value, the described estimated value of frequency deviation on a large scale to be selected and default scope Value obtains optimum frequency deviation estimated value.

Further, described default value range includes the first value range preset and the second value range preset, And described first value range is less than described second value range；

Correspondingly, according to described first frequency deviation estimated value, the described estimated value of frequency deviation on a large scale to be selected and pre- If value range obtain optimum frequency deviation estimated value, including:

When the described estimated value of frequency deviation on a large scale to be selected is in centered by described first frequency deviation estimated value, with Described first value range be length first interval in time, the frequency deviation estimated value of described optimum is described to be selected The meansigma methods of frequency deviation estimated value on a large scale；

When at least one in the described estimated value of frequency deviation on a large scale to be selected is in the second interval, described optimum Frequency deviation estimated value be but be in the meansigma methods of the estimated value of frequency deviation on a large scale to be selected in the second interval；Wherein, Described second interval is centered by described first frequency deviation estimated value, the district with described second value range as length Between deduct described first interval after the interval that obtains；

When the described estimated value of frequency deviation on a large scale to be selected is all not at described first interval and described second interval Time, the frequency deviation estimated value of described optimum is described first frequency deviation estimated value.

Further, the described repeatability according to cyclic prefix CP carries out frequency deviation estimation, obtains the first frequency deviation Estimated value, including:

Obtain CP sequence and the cross correlation value cor_CP of the original series identical with described CP sequence；

Time difference NT according to described CP sequence Yu described original series_sWith described cross correlation value cor_CP, Obtain the first frequency deviation estimated value f according to the following formula_cp:

$f_{\mathrm{cp}}=\frac{\mathrm{angle}(\mathrm{cor}\_\mathrm{CP})}{2\mathrm{\π}\×{\mathrm{NT}}_s}$

Wherein, angle () represents complex vector located and real axis positive direction angle.

Further, described by default pilot tone to obtain at least one second frequency deviation estimated value, including:

After the symbol of described pilot tone pair is carried out conjugate multiplication, then the result being multiplied is added up, obtain Angle value after Lei Jia

Angle value after adding upAnd the time difference Δ t between the symbol of pilot tone pair, obtain according to the following formula Described second frequency deviation estimated value f_Δ:

Wherein, f_ΔIn subscript Δ represent the pilot tone sequence number difference of described pilot tone pair,Span be (-π, π), f_ΔScope be:

Further, described obtain to be selected big according to described second frequency deviation estimated value and the operational rule preset Scope frequency deviation estimated value, including:

Two chosen in described second frequency deviation estimated value carry out calculus of differences, according to difference result according to presetting Difference result and frequency deviation offset between corresponding relation to carry out calculus of differences two second frequency deviations estimate Value carries out frequency deviation compensation respectively, obtains two frequency deviation estimated values on a large scale to be selected.

Second aspect, embodiments provides the device that a kind of frequency deviation is estimated, described device includes: the One estimation unit, the second estimation unit, the first acquiring unit and second acquisition unit, wherein,

Described first estimation unit, for carrying out frequency deviation estimation according to the repeatability of cyclic prefix CP, obtains First frequency deviation estimated value；

Described second estimation unit, is used for by default pilot tone obtaining at least one second frequency deviation estimated value；

Described first acquiring unit, for the second frequency deviation estimated value of obtaining according to described second estimation unit and The operational rule preset obtains frequency deviation estimated value on a large scale to be selected；

Described second acquisition unit, the first frequency deviation estimated value obtained for described first estimation unit, described The estimated value of frequency deviation on a large scale to be selected and default value range that first acquiring unit obtains obtain optimum frequency Estimated value partially.

Further, described default value range includes the first value range preset and the second value range preset, And described first value range is less than described second value range；

Correspondingly, described second acquisition unit, specifically for:

When the described estimated value of frequency deviation on a large scale to be selected is in centered by described first frequency deviation estimated value, with Described first value range be length first interval in time, the frequency deviation estimated value of described optimum is described to be selected The meansigma methods of frequency deviation estimated value on a large scale；

And, when at least one in the described estimated value of frequency deviation on a large scale to be selected is in the second interval, institute The frequency deviation estimated value stating optimum is but is in the meansigma methods of the estimated value of frequency deviation on a large scale to be selected in the second interval； Wherein, described second interval is centered by described first frequency deviation estimated value, with described second value range as length The interval that the interval of degree obtains after deducting described first interval；

And, when the described estimated value of frequency deviation on a large scale to be selected is all not at described first interval and described second Time interval, the frequency deviation estimated value of described optimum is described first frequency deviation estimated value.

Further, described first estimation unit, specifically for:

Obtain CP sequence and the cross correlation value cor_CP of the original series identical with described CP sequence；

And, according to time difference NT of described CP sequence Yu described original series_sWith described cross correlation value Cor_CP, obtains the first frequency deviation estimated value f according to the following formula_cp:

$f_{\mathrm{cp}}=\frac{\mathrm{angle}(\mathrm{cor}\_\mathrm{CP})}{2\mathrm{\π}\×{\mathrm{NT}}_s}$

Wherein, angle () represents complex vector located and real axis positive direction angle.

Further, described second estimation unit, specifically for:

After the symbol of described pilot tone pair is carried out conjugate multiplication, then the result being multiplied is added up, obtain Angle value after Lei Jia

Angle value after adding upAnd the time difference Δ t between the symbol of pilot tone pair, obtain according to the following formula Described second frequency deviation estimated value f_Δ:

Wherein, f_ΔIn subscript Δ represent the pilot tone sequence number difference of described pilot tone pair,Span be (-π, π), f_ΔScope be:

Further, described first acquiring unit, specifically for:

Two chosen in described second frequency deviation estimated value carry out calculus of differences, according to difference result according to presetting Difference result and frequency deviation offset between corresponding relation to carry out calculus of differences two second frequency deviations estimate Value carries out frequency deviation compensation respectively, obtains two frequency deviation estimated values on a large scale to be selected.

Embodiments provide the method and apparatus that a kind of frequency deviation is estimated, estimate by carrying out frequency deviation with CP Centered by evaluation, the frequency deviation estimated value and the default scope that obtain in conjunction with frequency pilot sign carry out frequency deviation on a large scale Estimate, for the problem of big frequency deviation, be not only able to improve frequency offset estimation accuracy, and it can be avoided that frequency occur The phenomenon of upset partially.

Accompanying drawing explanation

The method flow schematic diagram that Fig. 1 estimates for a kind of frequency deviation that the embodiment of the present invention provides；

The schematic symbol diagram of a kind of OFDM that Fig. 2 provides for the embodiment of the present invention；

The interval schematic diagram of one first that Fig. 3 provides for the embodiment of the present invention；

The interval schematic diagram of one second that Fig. 4 provides for the embodiment of the present invention；

The apparatus structure schematic diagram that Fig. 5 estimates for a kind of frequency deviation that the embodiment of the present invention provides.

Detailed description of the invention

Below in conjunction with the accompanying drawing in the embodiment of the present invention, the technical scheme in the embodiment of the present invention is carried out clearly Chu, it is fully described by.

See Fig. 1, the method that a kind of frequency deviation that it illustrates the embodiment of the present invention provides is estimated, can apply In the network equipment carrying out frequency deviation estimation according to downlink status, such as mobile terminal etc., the method can To include:

S101: carry out frequency deviation estimation according to the repeatability of cyclic prefix CP, obtains the first frequency deviation estimated value；

Exemplarily, in the present embodiment, step S101 specifically may include that

First, CP sequence and the cross correlation value cor_CP of the original series identical with CP sequence are obtained；

Then, according to time difference NT of CP sequence Yu original series_sWith cross correlation value cor_CP, according to formula (1) the first frequency deviation estimated value f is obtained_cp:

$f_{\mathrm{cp}}=\frac{\mathrm{angle}(\mathrm{cor}\_\mathrm{CP})}{2\mathrm{\π}\×{\mathrm{NT}}_s}---\left(1\right)$

Wherein, angle () represents complex vector located and real axis positive direction angle.

It should be noted that as in figure 2 it is shown, the CP sequence inserted in its protection interval of OFDM symbol Arranging identical with the tail end sequence data of OFDM symbol, therefore, shown in the shade in Fig. 2, OFDM accords with Number the original series that tail end sequence is CP sequence, owing to the data of two sequences are identical, though therefore warp Cross the transmission of multipath channel, between CP sequence and original series, just save time shift and the frequency displacement letter of channel Breath, can be obtained by the cross correlation value cor_CP of CP sequence and original series；

Specifically, the calculating process of the cross correlation value cor_CP of CP sequence and original series can be specifically $\mathrm{cor}\_\mathrm{CP}=\underset{n}{\mathrm{\Σ}}{d}^{\′}(n+N)*\mathrm{conj}\left(d^{\′}\left(n\right)\right)=\exp (j*2\mathrm{\π}*\mathrm{\Δf}*{\mathrm{NT}}_s)\underset{n}{\mathrm{\Σ}}{\left|d\left(n\right)\right|}^2;$ Wherein, conj () represents multiple Number vector carries out conjugate operation, and n represents the sampled point sampling OFDM symbol, and N represents two Between sequence, the sequence number of sampled point is poor, and d (n) is original series, and d ' (n) is CP sequence, and D ' (n)=d (n) * exp (j*2 π * Δ f*NT_s), wherein, Δ f is frequency deviation, NT_sIt it is the time difference between two sequences.

S102: by default pilot tone to obtaining at least one second frequency deviation estimated value, and according to the second frequency deviation Estimated value and the operational rule preset obtain frequency deviation estimated value on a large scale to be selected；

Exemplarily, by default pilot tone to obtaining at least one second frequency deviation estimated value, specifically can wrap Include:

First, after the symbol of pilot tone pair is carried out conjugate multiplication, then the result being multiplied is added up, obtain Take the angle value after adding up

Then, the angle value after adding upAnd the time difference Δ t between the symbol of pilot tone pair, according under Formula obtains the second frequency deviation estimated value f_Δ:

Wherein, f_ΔIn subscript Δ represent the pilot tone sequence number difference of pilot tone pair,Span be (-π, π), f_ΔScope be:

In the present embodiment, illustrate as a example by the frequency pilot sign of CRS, at Long Term Evolution (LTE, Long Term Evolution) system descending protocol in, it is stipulated that in CRS, serial number 0,4,7,11 leads Frequency symbol is used for carrying out frequency deviation estimation, and therefore, these four frequency pilot signs can obtainIndividual pilot tone pair, point Be not pilot tone serial number 4 and 7,0 and 4,7 and 11,0 and 7,4 and 11 and 0 and 11 these 6 lead The most right, according to above-mentioned process to these six pilot tones to respectively obtaining six the second frequency deviation estimated values, be respectively f₃、f_4a、f_4b、f_7a、f_7bAnd f₁₁, it is possible to understand that, due to the pilot tone of 0 and 4,7 and 11 pilot tones pair Sequence number difference is the pilot tone sequence number difference of 4,0 and 7,4 and 11 pilot tones pair and is 7, therefore, second In frequency deviation estimated value, the second obtained frequency deviation estimated value is entered by the different pilot tones that difference is identical with subscript a, b Row is distinguished.

Exemplarily, frequency deviation on a large scale to be selected is obtained according to the second frequency deviation estimated value and the operational rule preset Estimated value, specifically may include that

Two chosen in the second frequency deviation estimated value carry out calculus of differences, according to difference result according to default difference Two the second frequency deviation estimated values carrying out calculus of differences are divided by the corresponding relation point between result and frequency deviation offset Do not carry out frequency deviation compensation, obtain two frequency deviation estimated values on a large scale to be selected.

Specifically, illustrate as a example by aforesaid six the second frequency deviation estimated values, when obtaining six second frequencies Estimated value, is f respectively partially₃、f_4a、f_4b、f_7a、f_7bAnd f₁₁Afterwards, can estimate from these six the second frequency deviations Evaluation carries out calculus of differences two-by-two such that it is able to obtainIndividual difference result, according to 15 difference knots Fruit can obtain at mostIndividual frequency deviation estimated value on a large scale to be selected；It should be noted that In actual application, owing to frequency deviation region is too small, obtained frequency deviation is estimated by such as sequence number 0 and 11 pilot tone Scope is too small, and the quantity of M will usually be less than 30；

With f₃And f_4aAs a example by carrying out calculus of differences and obtaining the estimated value of frequency deviation on a large scale to be selected, it is assumed that f_4a-f₃ Result be 3.5kHz, then, preset the f corresponding to 3.5kHz₃Frequency deviation offset be 0, f_4aFrequency Offset compensation value is-1.75k × 2, then, respectively according to frequency deviation offset to f₃And f_4aAfter compensating, obtain The estimated value of frequency deviation on a large scale to be selected be f₃And f_4a-1.75k×2。

S103: according to the first frequency deviation estimated value, the estimated value of frequency deviation on a large scale to be selected and default value range Obtain optimum frequency deviation estimated value.

Exemplarily, the value range preset includes the first value range preset and the second value range preset, and First value range is less than the second value range；

Correspondingly, step S103 specifically may include that

When the estimated value of frequency deviation on a large scale to be selected is in centered by the first frequency deviation estimated value, with the first scope Time in the first interval that value is length, optimum frequency deviation estimated value is the flat of the estimated value of frequency deviation on a large scale to be selected Average；

When at least one in the estimated value of frequency deviation on a large scale to be selected is in the second interval, optimum frequency deviation is estimated Evaluation is but is in the meansigma methods of the estimated value of frequency deviation on a large scale to be selected in the second interval；Wherein, second is interval For centered by the first frequency deviation estimated value, the interval with the second value range as length obtains after deducting the first interval Interval；

When the estimated value of frequency deviation on a large scale to be selected is all not at the first interval and second is interval, optimum frequency deviation Estimated value is the first frequency deviation estimated value.

Specifically, the value range preset is typically according to set by conventional empirical data, at the present embodiment In, the first value range T₁200Hz, the second value range T can be preset as₂2kHz can be preset as, then, As a example by the estimated value of frequency deviation on a large scale to be selected obtained by step S102, frequency deviation estimated value on a large scale to be selected ForWherein M is the number of the estimated value of frequency deviation on a large scale to be selected, estimates with the first frequency deviation Value f_cpCentered by, by the first value range and the second value range pairScreen out, thus finally obtain Excellent frequency deviation estimated value, detailed process is:

If it is all ofThe most satisfiedThen optimum frequency deviation estimated valueCan manage Solve, in the present embodiment, as it is shown on figure 3, with the first frequency deviation estimated value f_cpCentered by, with the first value range T₁First is arranged interval, as shown in the solid heart linearity region in Fig. 3, when all of for lengthAll in During the first interval, optimum frequency deviation estimated value is all ofMeansigma methods；

If existingMeetThen will meet'sMiddle acquisition meets simultaneously'sForm setThe most optimum frequency deviation estimated valueWherein, N is setIn element number；It should be understood that work asMiddle existence is in the first frequency deviation estimated value f_cp Centered by, with the second value range T₁Second obtained after deducting the first interval for the interval of length is interval, such as figure Shown in solid heart linearity region shown in 4, work as existenceWhen being in the second interval, optimum frequency deviation estimated value For being in the second intervalMeansigma methods；

Other situations, the most all ofIt is satisfied bySo optimum frequency deviation estimated value Δ f=f_cp, It should be understood that when all ofI.e. it is not at the first interval, during not also in the second interval, optimum frequency Estimated value partially is the first frequency deviation estimated value.

Present embodiments provide a kind of method that frequency deviation is estimated, by carrying out centered by frequency deviation estimated value by CP, The frequency deviation estimated value obtained in conjunction with frequency pilot sign and default scope carry out frequency deviation on a large scale and estimate, for greatly The problem of frequency deviation, is not only able to improve frequency offset estimation accuracy, and it can be avoided that the phenomenon that frequency deviation overturns occurs.

In conjunction with the technology design that previous embodiment is identical, seeing Fig. 5, it illustrates the embodiment of the present invention provides A kind of frequency deviation estimate device 50, this device 50 can apply to carry out frequency deviation according to downlink status Estimate the network equipment in, this device 50 may include that first estimation unit the 501, second estimation unit 502, First acquiring unit 503 and second acquisition unit 504, wherein,

First estimation unit 501, for carrying out frequency deviation estimation according to the repeatability of cyclic prefix CP, obtains the One frequency deviation estimated value；

Second estimation unit 502, is used for by default pilot tone obtaining at least one second frequency deviation estimated value；

First acquiring unit 503, for the second frequency deviation estimated value of obtaining according to the second estimation unit 502 and The operational rule preset obtains frequency deviation estimated value on a large scale to be selected；

Second acquisition unit 504, the first frequency deviation estimated value obtained for the first estimation unit 501, first The estimated value of frequency deviation on a large scale to be selected and default value range that acquiring unit 503 obtains obtain optimum frequency Estimated value partially.

Further, the value range preset includes the first value range preset and the second value range preset, and First value range is less than the second value range；

Correspondingly, second acquisition unit 504, specifically for:

When the estimated value of frequency deviation on a large scale to be selected is in centered by the first frequency deviation estimated value, with the first scope Time in the first interval that value is length, optimum frequency deviation estimated value is the flat of the estimated value of frequency deviation on a large scale to be selected Average；

And, when at least one in the estimated value of frequency deviation on a large scale to be selected is in the second interval, optimum Frequency deviation estimated value is but is in the meansigma methods of the estimated value of frequency deviation on a large scale to be selected in the second interval；Wherein, Two intervals are centered by the first frequency deviation estimated value, and it is interval that the interval with the second value range as length deducts first After the interval that obtains；

And, when the estimated value of frequency deviation on a large scale to be selected is all not at the first interval and second is interval, optimum Frequency deviation estimated value be the first frequency deviation estimated value.

Further, the first estimation unit 501, specifically for:

Obtain CP sequence and the cross correlation value cor_CP of the original series identical with CP sequence；

And, according to time difference NT of CP sequence Yu original series_sWith cross correlation value cor_CP, according under Formula obtains the first frequency deviation estimated value f_cp:

$f_{\mathrm{cp}}=\frac{\mathrm{angle}(\mathrm{cor}\_\mathrm{CP})}{2\mathrm{\π}\×{\mathrm{NT}}_s}$

Wherein, angle () represents complex vector located and real axis positive direction angle.

Further, the second estimation unit 502, specifically for:

After the symbol of pilot tone pair is carried out conjugate multiplication, then the result being multiplied is added up, obtain cumulative After angle value

Angle value after adding upAnd the time difference Δ t between the symbol of pilot tone pair, obtain according to the following formula Second frequency deviation estimated value f_Δ:

Wherein, f_ΔIn subscript Δ represent the pilot tone sequence number difference of pilot tone pair,Span be (-π, π), f_ΔScope be:

Further, the first acquiring unit 503, specifically for:

Two chosen in the second frequency deviation estimated value carry out calculus of differences, according to difference result according to default difference Two the second frequency deviation estimated values carrying out calculus of differences are divided by the corresponding relation point between result and frequency deviation offset Do not carry out frequency deviation compensation, obtain two frequency deviation estimated values on a large scale to be selected.

Present embodiments provide the device 50 that a kind of frequency deviation is estimated, by carrying out during frequency deviation estimated value is with CP The heart, the frequency deviation estimated value obtained in conjunction with frequency pilot sign and default scope carry out frequency deviation estimation, pin on a large scale Problem to big frequency deviation, is not only able to improve frequency offset estimation accuracy, and it can be avoided that occurs what frequency deviation overturn Phenomenon.

Those skilled in the art are it should be appreciated that embodiments of the invention can be provided as method, system or meter Calculation machine program product.Therefore, the present invention can use hardware embodiment, software implementation or combine software and The form of the embodiment of hardware aspect.And, the present invention can use and wherein include calculating one or more The computer-usable storage medium of machine usable program code (includes but not limited to disk memory and optical storage Device etc.) form of the upper computer program implemented.

The present invention is with reference to method, equipment (system) and computer program according to embodiments of the present invention Flow chart and/or block diagram describe.It should be understood that can be by computer program instructions flowchart and/or side Flow process in each flow process in block diagram and/or square frame and flow chart and/or block diagram and/or the knot of square frame Close.Can provide these computer program instructions to general purpose computer, special-purpose computer, Embedded Processor or The processor of other programmable data processing device is to produce a machine so that by computer or other can The instruction that the processor of programming data processing equipment performs produces for realizing in one flow process or multiple of flow chart The device of the function specified in flow process and/or one square frame of block diagram or multiple square frame.

These computer program instructions may be alternatively stored in and can guide computer or other programmable data processing device In the computer-readable memory worked in a specific way so that be stored in this computer-readable memory Instruction produces the manufacture including command device, and this command device realizes at one flow process of flow chart or multiple stream The function specified in journey and/or one square frame of block diagram or multiple square frame.

These computer program instructions also can be loaded in computer or other programmable data processing device, makes Sequence of operations step must be performed to produce computer implemented place on computer or other programmable devices Reason, thus the instruction performed on computer or other programmable devices provides for realizing flow chart one The step of the function specified in flow process or multiple flow process and/or one square frame of block diagram or multiple square frame.

Above, only presently preferred embodiments of the present invention, it is not intended to limit protection scope of the present invention.

Claims (10)

1. the method that a frequency deviation is estimated, it is characterised in that described method includes:

Repeatability according to cyclic prefix CP carries out frequency deviation estimation, obtains the first frequency deviation estimated value；

By default pilot tone to obtaining at least one second frequency deviation estimated value, and estimate according to described second frequency deviation Evaluation and the operational rule preset obtain frequency deviation estimated value on a large scale to be selected；

According to described first frequency deviation estimated value, the described estimated value of frequency deviation on a large scale to be selected and default scope Value obtains optimum frequency deviation estimated value.

Method the most according to claim 1, it is characterised in that described default value range includes presetting The first value range and the second value range of presetting, and described first value range is less than described second value range；

Correspondingly, according to described first frequency deviation estimated value, the described estimated value of frequency deviation on a large scale to be selected and pre- If value range obtain optimum frequency deviation estimated value, including:

When the described estimated value of frequency deviation on a large scale to be selected is in centered by described first frequency deviation estimated value, with Described first value range be length first interval in time, the frequency deviation estimated value of described optimum is described to be selected The meansigma methods of frequency deviation estimated value on a large scale；

When at least one in the described estimated value of frequency deviation on a large scale to be selected is in the second interval, described optimum Frequency deviation estimated value be but be in the meansigma methods of the estimated value of frequency deviation on a large scale to be selected in the second interval；Wherein, Described second interval is centered by described first frequency deviation estimated value, the district with described second value range as length Between deduct described first interval after the interval that obtains；

When the described estimated value of frequency deviation on a large scale to be selected is all not at described first interval and described second interval Time, the frequency deviation estimated value of described optimum is described first frequency deviation estimated value.

Method the most according to claim 1, it is characterised in that the described weight according to cyclic prefix CP Renaturation carries out frequency deviation estimation, obtains the first frequency deviation estimated value, including:

Obtain CP sequence and the cross correlation value cor_CP of the original series identical with described CP sequence；

Time difference NT according to described CP sequence Yu described original series_sWith described cross correlation value cor_CP, Obtain the first frequency deviation estimated value f according to the following formula_cp:

$f_{\mathrm{cp}}=\frac{\mathrm{angle}(\mathrm{cor}\_\mathrm{CP})}{2\mathrm{\π}\×{\mathrm{NT}}_s}$

Wherein, angle () represents complex vector located and real axis positive direction angle.

Method the most according to claim 1, it is characterised in that described by default pilot tone to acquisition At least one second frequency deviation estimated value, including:

After the symbol of described pilot tone pair is carried out conjugate multiplication, then the result being multiplied is added up, obtain Angle value after Lei Jia

Angle value after adding upAnd the time difference Δ t between the symbol of pilot tone pair, obtain according to the following formula Described second frequency deviation estimated value f_Δ:

Wherein, f_ΔIn subscript Δ represent the pilot tone sequence number difference of described pilot tone pair,Span be (-π, π), f_ΔScope be:

Method the most according to claim 1, it is characterised in that described according to described second frequency deviation estimation Value and the operational rule preset obtain frequency deviation estimated value on a large scale to be selected, including:

Two chosen in described second frequency deviation estimated value carry out calculus of differences, according to difference result according to presetting Difference result and frequency deviation offset between corresponding relation to carry out calculus of differences two second frequency deviations estimate Value carries out frequency deviation compensation respectively, obtains two frequency deviation estimated values on a large scale to be selected.

6. the device that a frequency deviation is estimated, it is characterised in that described device includes: the first estimation unit, the Two estimation units, the first acquiring unit and second acquisition unit, wherein,

Described first estimation unit, for carrying out frequency deviation estimation according to the repeatability of cyclic prefix CP, obtains First frequency deviation estimated value；

Described second estimation unit, is used for by default pilot tone obtaining at least one second frequency deviation estimated value；

Described first acquiring unit, for the second frequency deviation estimated value of obtaining according to described second estimation unit and The operational rule preset obtains frequency deviation estimated value on a large scale to be selected；

Described second acquisition unit, the first frequency deviation estimated value obtained for described first estimation unit, described The estimated value of frequency deviation on a large scale to be selected and default value range that first acquiring unit obtains obtain optimum frequency Estimated value partially.

Device the most according to claim 6, it is characterised in that described default value range includes presetting The first value range and the second value range of presetting, and described first value range is less than described second value range；

Correspondingly, described second acquisition unit, specifically for:

When the described estimated value of frequency deviation on a large scale to be selected is in centered by described first frequency deviation estimated value, with Described first value range be length first interval in time, the frequency deviation estimated value of described optimum is described to be selected The meansigma methods of frequency deviation estimated value on a large scale；

And, when at least one in the described estimated value of frequency deviation on a large scale to be selected is in the second interval, institute The frequency deviation estimated value stating optimum is but is in the meansigma methods of the estimated value of frequency deviation on a large scale to be selected in the second interval； Wherein, described second interval is centered by described first frequency deviation estimated value, with described second value range as length The interval that the interval of degree obtains after deducting described first interval；

And, when the described estimated value of frequency deviation on a large scale to be selected is all not at described first interval and described second Time interval, the frequency deviation estimated value of described optimum is described first frequency deviation estimated value.

Device the most according to claim 6, it is characterised in that described first estimation unit, specifically uses In:

Obtain CP sequence and the cross correlation value cor_CP of the original series identical with described CP sequence；

And, according to time difference NT of described CP sequence Yu described original series_sWith described cross correlation value Cor_CP, obtains the first frequency deviation estimated value f according to the following formula_cp:

$f_{\mathrm{cp}}=\frac{\mathrm{angle}(\mathrm{cor}\_\mathrm{CP})}{2\mathrm{\π}\×{\mathrm{NT}}_s}$

Wherein, angle () represents complex vector located and real axis positive direction angle.

Device the most according to claim 6, it is characterised in that described second estimation unit, specifically uses In:

After the symbol of described pilot tone pair is carried out conjugate multiplication, then the result being multiplied is added up, obtain Angle value after Lei Jia

Angle value after adding upAnd the time difference Δ t between the symbol of pilot tone pair, obtain according to the following formula Described second frequency deviation estimated value f_Δ:

Wherein, f_ΔIn subscript Δ represent the pilot tone sequence number difference of described pilot tone pair,Span be (-π, π), f_ΔScope be:

Device the most according to claim 6, it is characterised in that described first acquiring unit, specifically For:

Two chosen in described second frequency deviation estimated value carry out calculus of differences, according to difference result according to presetting Difference result and frequency deviation offset between corresponding relation to carry out calculus of differences two second frequency deviations estimate Value carries out frequency deviation compensation respectively, obtains two frequency deviation estimated values on a large scale to be selected.