CN102594740A - Method and device for estimating frequency offset - Google Patents
Method and device for estimating frequency offset Download PDFInfo
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- CN102594740A CN102594740A CN2011100042994A CN201110004299A CN102594740A CN 102594740 A CN102594740 A CN 102594740A CN 2011100042994 A CN2011100042994 A CN 2011100042994A CN 201110004299 A CN201110004299 A CN 201110004299A CN 102594740 A CN102594740 A CN 102594740A
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Abstract
The invention discloses a method and a device for estimating frequency offset, which are used for improving the efficiency and the accuracy of the estimation of the frequency offset and for decreasing realization complexity. The method comprises the following steps of: receiving sending signal from a mobile terminal; computing an accurate channel estimated value corresponding to each sub-carrier which carries the sending signal; respectively computing the power value of the corresponding sub-carriers based on the accurate channel estimated values; determining resource blocks divided in a system, wherein each resource block comprises sub-carriers of a specified number; selecting a target resource block according to the corresponding power value of each sub-carrier; aiming at the preset reference symbol of each sub-carrier, computing frequency offset of business data symbol contained in each sub-carrier according to the accurate channel estimated value of each sub-carrier in the target resource block; and performing frequency offset compensation to the business data symbol according to frequency offset of the business data symbol corresponding to each sub-carrier. The invention further discloses a device for estimating the frequency offset.
Description
Technical field
The present invention relates to the communications field, relate in particular to a kind of frequency deviation estimating method and device.
Background technology
In wireless communication system; For multicarrier system, the skew of carrier frequency can cause interchannel to produce interference, especially in OFDM (OFDM) system; Need between subcarrier strict the maintenance synchronously, carrier frequency shift (hereinafter to be referred as frequency deviation) is brought, and to influence meeting more serious.In the practical application; In comparatively complicated time variation wireless channel; Exist such as the frequency departure between transmitter carrier and the receiver local oscillator or because the situation such as Doppler frequency shift that fast moving is brought; This orthogonality between all can heavy damage ofdm system subcarrier causes interference.In the 4th LTE of third-generation mobile communication system, adopted the OFDM technology, this will accomplish comparatively accurate frequency offset estimating, could effectively eliminate the interference of intercarrier.
The frequency deviation estimating method of tradition ofdm system is employed in time domain or frequency domain more and carries out related operation to the OFDM symbol, and after constantly adding up, asks phase place to estimate frequency deviation, and this needs restriction and certain cooperation that changes of some parameters and condition.Wherein, adopt the frequency domain auto-correlation algorithm to be divided into rough estimate and two stages of thin estimation, frequency offset estimation range and estimate variance are by autocorrelative interval determination; More little at interval, estimation range and estimate variance are big more, and be big more at interval; Estimation range and estimate variance are more little, in rough estimate and thin estimation procedure, need choose suitable interval; To seek big estimation range and little estimate variance, this just need find optimum auto-correlation at interval, implements the comparison difficulty; Simultaneously, between rough estimate and thin is estimated, switch back and forth and also increased the synchronous complexity of subcarrier; And the autocorrelative prerequisite of time domain is that two sections parameter symbols in the time slot are carried out accurately time synchronized, if having deviation, the phase angle that then obtains after the auto-correlation will have the information of all the other business datum parts slightly; Cause frequency offset estimating to exist than mistake, in the LTE system, the base station receives time domain data; And then will transform the data into frequency domain and carry out subsequent treatment, can not guarantee to carry out precise synchronization in time domain in advance, therefore adopt the time domain auto-correlation to carry out frequency offset estimating and can not get the prerequisite guarantee; Simultaneously; Be transformed into time domain from frequency domain and need carry out inverse Fourier transform IFFT, need to consume great amount of time, and increase circuit complexity.
Summary of the invention
The present invention provides a kind of frequency deviation estimating method and device, in order to the efficient and the accuracy of raising frequency offset estimating, and the resource of reduction system consumption, reduce the hardware implementation complexity.
The concrete technical scheme that the embodiment of the invention provides is following:
A kind of frequency deviation estimating method comprises:
The transmission signal of mobile terminal receive calculates the corresponding accurate channel estimation value of each subcarrier of carrying said transmission signal respectively;
Based on each accurate channel estimation value that obtains, calculate the performance number of corresponding subcarrier respectively;
Confirm the Resource Block of intrasystem division, wherein, comprise the subcarrier that specifies number in each Resource Block, and the performance number corresponding according to each subcarrier, the target resource piece chosen;
Respectively according to the accurate channel estimation value of each subcarrier in the said target resource piece, and to the preset reference symbol of each subcarrier, calculate the frequency offset estimating value of the business datum symbol that each subcarrier comprises;
According to the frequency offset estimating value of each subcarrier corresponding service data symbol, the business datum symbol is carried out the frequency adjustment.
A kind of frequency deviation estimation device comprises:
Accurate channel estimation module is used for the transmission signal of mobile terminal receive, calculates the corresponding accurate channel estimation value of each subcarrier of carrying said transmission signal respectively;
Power computation module is used for based on each accurate channel estimation value that obtains, and calculates the performance number of corresponding subcarrier respectively;
Resource Block is selected module, is used for confirming the Resource Block of intrasystem division, wherein, comprises the subcarrier that specifies number in each Resource Block, and the performance number corresponding according to each subcarrier, chooses the target resource piece;
Frequency deviation estimating modules is used for respectively the accurate channel estimation value according to said each subcarrier of target resource piece, and to the preset reference symbol of each subcarrier, calculates the frequency offset estimating value of the business datum symbol that each subcarrier comprises;
Adjusting module is used for the frequency offset estimating value according to each subcarrier corresponding service data symbol, and the business datum symbol is carried out the frequency adjustment.
Based on technique scheme; Through obtaining the accurate channel estimation value of each subcarrier; Calculate the performance number of corresponding subcarrier respectively, the performance number corresponding according to each subcarrier chosen the target resource piece; Respectively according to the accurate channel estimation value of each subcarrier in the target resource piece; Calculate the frequency offset estimating value of the business datum symbol that each subcarrier comprises through the reference symbol of setting,, the business datum symbol is carried out the frequency adjustment according to the frequency offset estimating value of each subcarrier corresponding service data symbol.Thereby can improve the efficient and the accuracy of frequency offset estimating effectively, and reduce the resource of system consumption, reduce the hardware implementation complexity.
Description of drawings
Fig. 1 is a frequency offset estimating system architecture diagram of the present invention;
Fig. 2 is a frequency deviation estimation device structure chart of the present invention;
Fig. 3 is a frequency deviation estimating method flow chart of the present invention;
Fig. 4 is the structural representation of Frame of the present invention;
Fig. 5 is a time-frequency structure sketch map of the present invention.
Embodiment
For efficient and the accuracy that improves frequency offset estimating; And the resource of reduction system consumption; Reduce the hardware implementation complexity, the embodiment of the invention provides a kind of frequency deviation estimating method and device, can improve the efficient and the accuracy of frequency offset estimating effectively; And the resource of reduction system consumption, reduce the hardware implementation complexity.This method is: the transmission signal of mobile terminal receive, calculate respectively and carry the corresponding accurate channel estimation value of each subcarrier of sending signal, based on each accurate channel estimation value that obtains; Calculate the performance number of corresponding subcarrier respectively, confirm the Resource Block of intrasystem division, wherein; Comprise the subcarrier that specifies number in each Resource Block; And the performance number corresponding according to each subcarrier, choose the target resource piece, respectively according to the accurate channel estimation value of each subcarrier in the target resource piece; And to the preset reference symbol of each subcarrier; Calculate the frequency offset estimating value of the business datum symbol that each subcarrier comprises,, the business datum symbol is carried out the frequency adjustment according to the frequency offset estimating value of each subcarrier corresponding service data symbol.
Below in conjunction with accompanying drawing the preferred embodiment of the invention is elaborated.
The method that the embodiment of the invention provides can be applied to various ofdm systems, in following examples, is that example describes with the LTE system only.
Consult shown in the accompanying drawing 1, in the embodiment of the invention, the frequency offset estimating system mainly is made up of frequency deviation estimation device 10 and portable terminal 11, wherein,
Frequency deviation estimation device 10 is used for the transmission signal of mobile terminal receive 11, calculates respectively to carry the corresponding accurate channel estimation value of each subcarrier of sending signal; Based on each accurate channel estimation value that obtains, calculate the performance number of corresponding subcarrier respectively, confirm the Resource Block of intrasystem division; Wherein, comprise the subcarrier that specifies number in each Resource Block, and the performance number corresponding according to each subcarrier; Choose the target resource piece; Respectively according to the accurate channel estimation value of each subcarrier in the target resource piece, and to the preset reference symbol of each subcarrier, calculate the frequency offset estimating value of the business datum symbol that each subcarrier comprises; According to the frequency offset estimating value of each subcarrier corresponding service data symbol, the business datum symbol is carried out the frequency adjustment;
Consult shown in the accompanying drawing 2, in the embodiment of the invention, frequency deviation estimation device 10 mainly is made up of following module:
Accurate channel estimation module 101 is used for the transmission signal of mobile terminal receive, calculates the corresponding accurate channel estimation value of each subcarrier of carrying said transmission signal respectively;
Power computation module 102 is used for based on each accurate channel estimation value that obtains, and calculates the performance number of corresponding subcarrier respectively;
Resource Block is selected module 103, is used for confirming the Resource Block of intrasystem division, wherein, comprises the subcarrier that specifies number in each Resource Block, and the performance number corresponding according to each subcarrier, chooses the target resource piece;
Frequency deviation estimating modules 104 is used for respectively the accurate channel estimation value according to said each subcarrier of target resource piece, and to the preset reference symbol of each subcarrier, calculates the frequency offset estimating value of the business datum symbol that each subcarrier comprises;
Adjusting module 105 is used for the frequency offset estimating value according to each subcarrier corresponding service data symbol, and the business datum symbol is carried out the frequency adjustment.
Consult shown in the accompanying drawing 3, in the embodiment of the invention, the detailed process of frequency deviation estimating method is following:
Step 301: the transmission signal of mobile terminal receive, calculate respectively and carry the corresponding accurate channel estimation value of each subcarrier of sending signal.
The transmission signal of mobile terminal receive; Calculate respectively and carry the corresponding accurate channel estimation value of each subcarrier of sending signal; Be specially: the transmission signal of mobile terminal receive; Obtain the rough channel estimation value of each subcarrier according to sending signal, after the rough channel estimation value of the rough channel estimation value of each subcarrier and the N number of sub-carrier of being separated by is multiplied each other and adds up, be worth partially when calculating phase angle and obtaining portable terminal overall; Adopt to obtain overall the time be worth partially, calculate each subcarrier the time inclined to one side, and according to each subcarrier the time inclined to one side, accordingly the rough channel estimation value of each subcarrier is carried out partial compensation for the time, inclined to one side accurate channel estimation value when being eliminated.
Wherein, the transmission signal of the portable terminal that the base station receives is local prevision signal, and the base station receives the above-mentioned prevision signal that this portable terminal sends, and carries out rough channel estimation based on this prevision signal.Preferably, (Least Square, LS) channel estimation methods carries out rough channel estimation can to adopt least square.
For example, consult shown in the accompanying drawing 4, in the LTE system; Portable terminal sends signal with the form of Frame, and each Frame comprises 10 sub-frame, and each subframe comprises two time slots; In each time slot, can comprise 6 or 7 OFDM symbols again; In the embodiment of the invention, at each subframe centre position preset reference symbol, the remainder of each subframe is the business datum symbol.Can adopt least square (Least Square; LS) channel estimation methods carries out rough channel estimation; Be specially: the prevision signal that the base station mobile terminal receive sends and carry out demodulation after; To each subcarrier of signal after the carrying demodulation, the signal after the demodulation and the conjugation of prevision signal are carried out dot product, obtain the rough channel estimation value of each subcarrier respectively.Wherein, carry out the LS rough channel estimation to each corresponding number of sub-carrier of the reference symbol place of two time slots of each subframe.
Wherein, After the rough channel estimation value of the rough channel estimation value of each subcarrier and the N number of sub-carrier of being separated by multiplied each other and add up; Be worth partially when calculating phase angle and obtaining portable terminal overall; Be specially: the rough channel estimation value of the rough channel estimation value of each subcarrier and the N number of sub-carrier of being separated by is multiplied each other and phase angle is calculated in the back of adding up, and preferably N is 6, and this phase angle is worth when being portable terminal overall partially; Again with the phase angle that calculates divided by N promptly obtain each subcarrier of portable terminal the time be worth partially, computing formula can be expressed as
Wherein, t
0Represent this portable terminal in this time slot the time be worth H partially
LS(k) the rough channel estimation value of expression k number of sub-carrier, conj (H
LS(k+N)) conjugation of the rough channel estimation value of expression k+N number of sub-carrier, M representes the total number of sub-carriers of this portable terminal.
In the embodiment of the invention; After the rough channel estimation value of the rough channel estimation value of each subcarrier and the N number of sub-carrier of being separated by multiplied each other and add up; Calculate phase angle and can adopt following method: carry out approximate calculation, calculate phase angle through arctan function, at first; After arctan function carried out first derivation, according to any 1 x of Taylor's formula
0Near have
F (x wherein
0)=arctan (x
0).In the embodiment of the invention, preset three look-up tables, with quick calculating phase angle f (x), wherein, through preset x in the look-up table 1
0Value, preset arctan (x in the look-up table 2
0) value, preset in the look-up table 3
Value, the value of three tables is for one to one, for example, the pairing value of the 10th row in the look-up table 1; Corresponding with the value of the 10th row in look-up table 2 and 3, i.e. phase angle f (x)=LUT (index, 2)+LUT (index, 3) (x-LUT (index; 1)), the capable corresponding value of the index of LUT (index, 1) expression look-up table 1 wherein; LUT (index, 2), LUT (index, 3) are similar with it.
Wherein, According to each subcarrier the time inclined to one side; Accordingly the rough channel estimation value of each subcarrier is carried out partial compensation for the time; Inclined to one side accurate channel estimation value when being eliminated; Computing formula is
H (k) expression accurate channel estimation value after partially when eliminating, and k representes k carrier wave.
Step 302:, calculate the performance number of corresponding subcarrier respectively based on each accurate channel estimation value that obtains.
According to the accurate channel estimation value H (k) of each subcarrier, calculate the performance number of each number of sub-carrier, computing formula is expressed as: P=H (k) conj (H (k))=real
2(H (k))+imag
2(H (k)), P representes the performance number of subcarrier, real
2(H (k)) expression accurate channel estimation value real part square, imag
2(H (k)) expression accurate channel estimation value imaginary part square.
Step 303: confirm the Resource Block of intrasystem division, wherein, comprise the subcarrier that specifies number in each Resource Block, and the performance number corresponding according to each subcarrier, choose the target resource piece.
Resource Block for different system divides is also inequality, and the number of the subcarrier that each Resource Block comprises is also inequality, and for example, for the LTE system, each Resource Block comprises 12 number of sub-carrier, corresponding 10 Resource Block of each portable terminal.
The target resource piece is meant best resource blocks, and promptly (performance number is minimum) chosen the best channel of decline situation as representative in big fading channel.In the embodiment of the invention, be that unit carries out the channel selection, in each Resource Block, select the representative power of minimal power values, with expression channel fading situation as Resource Block with the Resource Block.
Wherein, the performance number corresponding according to each subcarrier chosen the target resource piece, is specially: the performance number corresponding according to each subcarrier selects the minimum sub-carrier power value in each Resource Block respectively; Minimum sub-carrier power value to from each Resource Block, choosing compares, and therefrom chooses the maximum sub-carrier power value of each sub-frame, and respectively that maximum sub-carrier power value is corresponding Resource Block is as the target resource piece.
In the embodiment of the invention; At the Resource Block that maximum sub-carrier power value is corresponding during as the target resource piece; At first confirm the subframe that the corresponding subcarrier of maximum sub-carrier power value comprises; The Resource Block that first time slot reference symbol place of above-mentioned subframe is corresponding is as the target resource piece of above-mentioned subframe, promptly simultaneously with the target resource piece of this target resource piece as second time slot reference symbol of above-mentioned subframe place correspondence.
Step 304: respectively according to the accurate channel estimation value of each subcarrier in the target resource piece, and to the preset reference symbol of each subcarrier, calculate the frequency offset estimating value of the business datum symbol that each subcarrier comprises.
Character according to Fourier transform can be known; The frequency domain skew shows as phase angle and changes on time domain, therefore, only need two time slots of subframe are transformed to time domain in the accurate channel estimating of frequency domain; And calculate the time domain phase angle, can know the frequency deviation of each subcarrier that carries this subframe through the variation of phase angle.
This step is specially: according to the accurate channel estimation value of each subcarrier in the target resource piece; And to the preset reference symbol of each subcarrier; Calculate respectively and the corresponding time domain of each the subcarrier accurate channel estimation value value at zero point, and calculate the frequency offset estimating value at said target resource piece corresponding reference symbol place based on the value at time domain zero point; It is poor respectively the frequency offset estimating value at two reference symbol places that obtain continuously on each subcarrier in the said target resource piece to be done; Obtain the frequency offset estimating value between two reference symbols on the above-mentioned subcarrier respectively, and calculate the frequency offset estimating value of the business datum symbol that corresponding subcarrier comprises based on the frequency offset estimating value between two reference symbols on each subcarrier respectively.
Preferably; When the value of calculating respectively with the corresponding time domain of each subcarrier accurate channel estimation value zero point; Respectively with each subcarrier accurate channel estimation value through inverse Fourier transform to time domain, and the mean value of the accurate channel estimation value of preceding 2 index times number of sub-carrier in the frequency domain is approximately the said time domain value at zero point.Because the signal of accurate channel estimating on frequency domain of each subcarrier is truncation funcation form (like window function) on the Resource Block; With its form that is transformed into after the time domain is sync (x)=sin x/x; Its most of concentration of energy is (being near zero point) in main lobe, and the value that can directly choose time domain zero point is carried out phase angle and calculated.
Formula
according to inverse Fourier transform can be known; Time domain zero point value is formulated as
here X (k) be accurate channel estimation value H (K); N is the number of the subcarrier that Resource Block comprises; Preferably; N be 2 index doubly, calculate the corresponding phase angle
of this Resource Block again
For example; In the LTE system; Comprise 12 number of sub-carrier in the Resource Block; Realize for ease of hardware; The accurate channel estimation value mean value of getting preceding 8 number of sub-carrier is as the time domain value at zero point, is expressed as
phase angle
then
Reference symbol for two time slots of same subframe that obtain continuously on each subcarrier in the target resource piece; Calculate the corresponding phase angle of each time slot reference symbol according to above-mentioned steps respectively; Obtain
because the base station is a multiaerial system respectively; Can be in the hope of a plurality of antenna angle values average, the mean value of gained is respectively as the final angle values of above-mentioned subframe to deserved each time slot reference symbol.After calculating the phase angle of each time slot reference symbol; Deduct the corresponding phase angle of last time slot with the back corresponding phase angle of one time slot; Frequency deviation between two time slot reference symbols that promptly obtain to obtain continuously on each subcarrier in the target resource piece in the frequency domain; Frequency deviation between the above-mentioned reference symbol is controlled in the scope of positive and negative π through adding and subtracting 2 π, further obtains the frequency deviation of the business datum symbol that corresponding subcarrier comprises again based on the frequency deviation between two reference symbols on each subcarrier.
Preferably; When the frequency deviation on respectively based on each subcarrier between the reference symbol is obtained the frequency deviation of the business datum symbol that corresponding subcarrier comprises; Demarcate first reference symbol place and do not have frequency deviation, the frequency deviation between the adjacent OFDM symbol that obtains continuously based on the corresponding subcarrier of the frequency offset calculation between two reference symbols on each number of sub-carrier is based on the frequency deviation between this adjacent OFDM symbol; Carry out linear interpolation, the frequency deviation between the business datum symbol that the calculating respective sub comprises.
For example; Consult shown in the accompanying drawing 5, suppose in the LTE system, each time slot that subframe comprises is made up of 7 OFDM symbols; To be positioned at the middle symbol of each time slot and be set at reference symbol; All the other are the business datum symbol, and promptly the 4th of each time slot the symbol is reference symbol, 6 the business datum symbols of then being separated by between the reference symbol of two time slots.Behind the select target Resource Block; It is poor that the frequency offset estimating value at two time slot reference symbol places that each subcarrier in the target resource piece is obtained is continuously done, and the phase angle that is about to second corresponding time slot reference symbol place of each number of sub-carrier deducts the phase angle at the first time slot reference symbol place on the respective sub, obtains on each subcarrier the frequency deviation between two reference symbols; With the frequency deviation between two reference symbols on each subcarrier divided by (6+1); Obtain the frequency deviation between each subcarrier adjacent OFDM symbol respectively, in the embodiment of the invention, demarcate the reference symbol (the 4th symbol) of each first time slot of subcarrier and locate not exist frequency deviation; Then the frequency deviation at the 5th symbol place is the frequency deviation between the above-mentioned adjacent OFDM symbol; Add the frequency deviation between the adjacent OFDM symbol on the basis that the 6th symbol place is the 5th symbol frequency deviation, and the like, until last symbol of second time slot; Then be the frequency deviation at negative adjacent OFDM symbol place for the frequency deviation at the 3rd symbol place; The frequency deviation at the 2nd symbol place then is the frequency deviation of adding negative adjacent OFDM symbol place on the basis of frequency deviation at the 3rd symbol place, and the like, then can calculate the frequency deviation of the business datum symbol that each subcarrier comprises.
Step 305:, the business datum symbol is carried out the frequency adjustment according to the frequency offset estimating value of each subcarrier corresponding service data symbol.
Based on technique scheme, in the embodiment of the invention, through obtaining the accurate channel estimation value of each subcarrier; Calculate the performance number of corresponding subcarrier respectively; The performance number corresponding according to each subcarrier chosen the target resource piece, respectively according to the accurate channel estimation value of each subcarrier in the target resource piece; And to the preset reference symbol of each subcarrier; Calculate the frequency offset estimating value of the business datum symbol that each subcarrier comprises,, the business datum symbol is carried out the frequency adjustment according to the frequency offset estimating value of each subcarrier corresponding service data symbol.For adopting the frequency domain auto-correlation algorithm to carry out the method for frequency offset estimating; The method that the embodiment of the invention provides; Need not use the frequency domain auto-correlation algorithm can realize frequency offset estimating; Overcome auto-correlation in the frequency domain auto-correlation algorithm and be difficult to the difficulty chosen at interval, also need between rough estimate and thin is estimated, not switch back and forth, improved the efficient and the accuracy of frequency offset estimating; For adopting the time domain auto-correlation algorithm to carry out the method for frequency offset estimating, overcome the shortcoming that just can bring big frequency offset error without strict retention time precise synchronization; In addition, the present invention only need obtain time domain zero point in the computational process of Resource Block frequency domain conversion time domain, therefore replaced the FFT computing of calculation of complex and bigger consumption circuit resource with arithmetic average; Simultaneously, also need not to construct training matrix or to channel impulse response filtering etc., be convenient to hardware and realize.
In sum, the frequency deviation estimating method that the embodiment of the invention provides can improve the efficient and the accuracy of frequency offset estimating, and reduces the resource of system consumption, reduces the hardware implementation complexity.
Obviously, those skilled in the art can carry out various changes and modification to the present invention and not break away from the spirit and scope of the present invention.Like this, belong within the scope of claim of the present invention and equivalent technologies thereof if of the present invention these are revised with modification, then the present invention also is intended to comprise these changes and modification interior.
Claims (12)
1. a frequency deviation estimating method is characterized in that, comprising:
The transmission signal of mobile terminal receive calculates the corresponding accurate channel estimation value of each subcarrier of carrying said transmission signal respectively;
Based on each accurate channel estimation value that obtains, calculate the performance number of corresponding subcarrier respectively;
Confirm the Resource Block of intrasystem division, wherein, comprise the subcarrier that specifies number in each Resource Block, and the performance number corresponding according to each subcarrier, the target resource piece chosen;
Respectively according to the accurate channel estimation value of each subcarrier in the said target resource piece, and to the preset reference symbol of each subcarrier, calculate the frequency offset estimating value of the business datum symbol that each subcarrier comprises;
According to the frequency offset estimating value of each subcarrier corresponding service data symbol, the business datum symbol is carried out the frequency adjustment.
2. the method for claim 1 is characterized in that, the transmission signal of mobile terminal receive calculates the corresponding accurate channel estimation value of each subcarrier of carrying said transmission signal respectively, comprising:
The transmission signal of mobile terminal receive; Obtain the rough channel estimation value of each subcarrier according to said transmission signal; After the rough channel estimation value of the rough channel estimation value of each subcarrier and the N number of sub-carrier of being separated by multiplied each other and add up, be worth partially when calculating phase angle and obtaining said portable terminal overall;
Adopt to obtain overall the time be worth partially, calculate each subcarrier the time inclined to one side, and according to said each subcarrier the time inclined to one side, accordingly the rough channel estimation value of each subcarrier is carried out partial compensation for the time, inclined to one side accurate channel estimation value when being eliminated.
3. according to claim 1 or claim 2 method is characterized in that, the performance number corresponding according to each subcarrier chosen the target resource piece, comprising:
The performance number corresponding according to each subcarrier selects the minimum sub-carrier power value in each Resource Block respectively;
Minimum sub-carrier power value to from each Resource Block, choosing compares, and therefrom chooses maximum sub-carrier power value, and the Resource Block that said maximum sub-carrier power value is corresponding is as the target resource piece.
4. method as claimed in claim 3 is characterized in that, the Resource Block that said maximum sub-carrier power value is corresponding comprises as the target resource piece:
Confirm the subframe that the corresponding subcarrier of said maximum sub-carrier power value comprises;
The Resource Block that first time slot reference symbol place of said subframe is corresponding is as the target resource piece of said subframe.
5. the method for claim 1; It is characterized in that, respectively according to the accurate channel estimation value of each subcarrier in the said target resource piece, and to the preset reference symbol of each subcarrier; Calculate the frequency offset estimating value of the business datum symbol that each subcarrier comprises, comprising:
Accurate channel estimation value according to each subcarrier in the target resource piece; And to the preset reference symbol of each subcarrier; Calculate respectively and the corresponding time domain of each the subcarrier accurate channel estimation value value at zero point, and calculate the frequency offset estimating value at said target resource piece corresponding reference symbol place based on the value at said time domain zero point;
It is poor respectively the frequency offset estimating value at two reference symbol places that obtain continuously on each subcarrier in the said target resource piece to be done; Obtain the frequency offset estimating value between two reference symbols on said each subcarrier respectively, and calculate the frequency offset estimating value of the business datum symbol that corresponding subcarrier comprises based on the frequency offset estimating value between two reference symbols on each subcarrier respectively.
6. method as claimed in claim 5 is characterized in that, when calculating the value with the corresponding time domain of each subcarrier accurate channel estimation value zero point respectively, comprising:
Respectively each subcarrier accurate channel estimation value is transformed to time domain through inverse Fourier transform, and the mean value of the accurate channel estimation value of preceding 2 index times number of sub-carrier in the frequency domain is approximately the said time domain value at zero point.
7. a frequency deviation estimation device is characterized in that, comprising:
Accurate channel estimation module is used for the transmission signal of mobile terminal receive, calculates the corresponding accurate channel estimation value of each subcarrier of carrying said transmission signal respectively;
Power computation module is used for based on each accurate channel estimation value that obtains, and calculates the performance number of corresponding subcarrier respectively;
Resource Block is selected module, is used for confirming the Resource Block of intrasystem division, wherein, comprises the subcarrier that specifies number in each Resource Block, and the performance number corresponding according to each subcarrier, chooses the target resource piece;
Frequency deviation estimating modules is used for respectively the accurate channel estimation value according to said each subcarrier of target resource piece, and to the preset reference symbol of each subcarrier, calculates the frequency offset estimating value of the business datum symbol that each subcarrier comprises;
Adjusting module is used for the frequency offset estimating value according to each subcarrier corresponding service data symbol, and the business datum symbol is carried out the frequency adjustment.
8. device as claimed in claim 7 is characterized in that, the transmission signal of said accurate channel estimation module mobile terminal receive calculates the corresponding accurate channel estimation value of each subcarrier of carrying said transmission signal respectively, is specially:
The transmission signal of mobile terminal receive; Obtain the rough channel estimation value of each subcarrier according to said transmission signal; After the rough channel estimation value of the rough channel estimation value of each subcarrier and the N number of sub-carrier of being separated by multiplied each other and add up, be worth partially when calculating phase angle and obtaining said portable terminal overall;
Adopt to obtain overall the time be worth partially, calculate each subcarrier the time inclined to one side, and according to said each subcarrier the time inclined to one side, accordingly the rough channel estimation value of each subcarrier is carried out partial compensation for the time, inclined to one side accurate channel estimation value when being eliminated.
9. like claim 7 or 8 described devices, it is characterized in that said Resource Block is selected the module performance number corresponding according to each subcarrier, chooses the target resource piece, is specially:
The performance number corresponding according to each subcarrier selects the minimum sub-carrier power value in each Resource Block respectively;
Minimum sub-carrier power value to from each Resource Block, choosing compares, and therefrom chooses maximum sub-carrier power value, and the Resource Block that said maximum sub-carrier power value is corresponding is as the target resource piece.
10. device as claimed in claim 9; It is characterized in that; When said Resource Block is selected the module Resource Block that said maximum sub-carrier power value is corresponding as the target resource piece; Confirm the subframe that the corresponding subcarrier of said maximum sub-carrier power value comprises, the Resource Block that first time slot reference symbol place of said subframe is corresponding is as the target resource piece of said subframe.
11. device as claimed in claim 7; It is characterized in that; Said frequency deviation estimating modules is respectively according to the accurate channel estimation value of each subcarrier in the said target resource piece; And, calculate the frequency offset estimating value of the business datum symbol that each subcarrier comprises to the preset reference symbol of each subcarrier, be specially:
Accurate channel estimation value according to each subcarrier in the target resource piece; And to the preset reference symbol of each subcarrier; Calculate respectively and the corresponding time domain of each the subcarrier accurate channel estimation value value at zero point, and calculate the frequency offset estimating value at said target resource piece corresponding reference symbol place based on the value at said time domain zero point;
It is poor respectively the frequency offset estimating value at two reference symbol places that obtain continuously on each subcarrier in the said target resource piece to be done; Obtain the frequency offset estimating value between two reference symbols on said each subcarrier respectively, and calculate the frequency offset estimating value of the business datum symbol that corresponding subcarrier comprises based on the frequency offset estimating value between two reference symbols on each subcarrier respectively.
12. device as claimed in claim 11; It is characterized in that; When said frequency deviation estimating modules is calculated the value with the corresponding time domain of each subcarrier accurate channel estimation value zero point respectively; Respectively each subcarrier accurate channel estimation value is transformed to time domain through inverse Fourier transform, and the mean value of the accurate channel estimation value of preceding 2 index times number of sub-carrier in the frequency domain is approximately the said time domain value at zero point.
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| CN104873222A (en) * | 2015-05-08 | 2015-09-02 | 浙江铭众生物医学创业投资有限公司 | Fetal heart rate detection method based on smart mobile terminal |
| CN108901070A (en) * | 2018-06-12 | 2018-11-27 | Oppo广东移动通信有限公司 | Wireless communication transmission method, device, mobile terminal and computer-readable storage medium |
| CN110602014A (en) * | 2019-09-11 | 2019-12-20 | 武汉剑通信息技术有限公司 | Sampling time deviation estimation method based on LTE downlink reference signal |
| CN113055995A (en) * | 2019-12-26 | 2021-06-29 | 中兴通讯股份有限公司 | Frequency offset estimation method and device |
| CN114257480A (en) * | 2020-09-23 | 2022-03-29 | 紫光展锐(重庆)科技有限公司 | Frequency offset estimation method and device, storage medium and terminal |
| CN116633749A (en) * | 2023-07-24 | 2023-08-22 | 北京智芯微电子科技有限公司 | Frequency offset estimation method, frequency offset compensation method and system, storage medium and chip thereof |
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Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN104873222A (en) * | 2015-05-08 | 2015-09-02 | 浙江铭众生物医学创业投资有限公司 | Fetal heart rate detection method based on smart mobile terminal |
| CN108901070A (en) * | 2018-06-12 | 2018-11-27 | Oppo广东移动通信有限公司 | Wireless communication transmission method, device, mobile terminal and computer-readable storage medium |
| CN110602014A (en) * | 2019-09-11 | 2019-12-20 | 武汉剑通信息技术有限公司 | Sampling time deviation estimation method based on LTE downlink reference signal |
| CN110602014B (en) * | 2019-09-11 | 2022-03-11 | 武汉精盾信息技术有限公司 | Sampling time deviation estimation method based on LTE downlink reference signal |
| CN113055995A (en) * | 2019-12-26 | 2021-06-29 | 中兴通讯股份有限公司 | Frequency offset estimation method and device |
| CN113055995B (en) * | 2019-12-26 | 2023-10-27 | 中兴通讯股份有限公司 | Frequency offset estimation method and device |
| CN114257480A (en) * | 2020-09-23 | 2022-03-29 | 紫光展锐(重庆)科技有限公司 | Frequency offset estimation method and device, storage medium and terminal |
| CN114257480B (en) * | 2020-09-23 | 2023-09-15 | 紫光展锐(重庆)科技有限公司 | Frequency offset estimation method and device, storage medium and terminal |
| CN116633749A (en) * | 2023-07-24 | 2023-08-22 | 北京智芯微电子科技有限公司 | Frequency offset estimation method, frequency offset compensation method and system, storage medium and chip thereof |
| CN116633749B (en) * | 2023-07-24 | 2023-12-29 | 北京智芯微电子科技有限公司 | Frequency offset estimation method, frequency offset compensation method and system, storage medium and chip thereof |
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