CN101917370A - Method and device for expanding frequency offset estimation range of demodulation data - Google Patents

Abstract

The invention discloses a method and a device for expanding a frequency offset estimation range of demodulation data. The method comprises the following steps of: pre-compensating first demodulation data with at least one first frequency value to acquire at least one second demodulation data; calculating at least one second frequency offset value of the at least one second demodulation data respectively, and compensating the second demodulation data according to the second frequency offset value respectively to acquire at least one third demodulation data; and evaluating the phase dispersion of the at least one third demodulation data respectively, determining the third demodulation data with the minimum phase dispersion and acquiring the frequency offset compensation value of the third demodulation data with the minimum phase dispersion, wherein the frequency offset compensation value is used as a frequency offset estimation result and is the accumulation of the first frequency offset value and the second frequency offset value. By expanding the demodulation data-based frequency offset estimation range, a more accurate frequency offset estimation value can be acquired.

Description

A kind of method and apparatus that enlarges the frequency offset estimation range of demodulating data

Technical field

The present invention relates generally to wireless communication field, is meant a kind of method and apparatus that enlarges the frequency offset estimation range of demodulating data especially.

Background technology

Along with the development of radio communication cause with popularize, mobile communication subscriber quantity is increasing exponentially, and especially Zhong Guo mobile subscriber is increasing with the speed more than 150% over the years always.The user is also more and more higher to the speed and the quality requirement of communication.In wireless communication system, when user terminal is started shooting, there is big frequency departure between carrier frequency and the local crystal oscillator, in addition, owing to the Doppler frequency shift that the portable terminal fast moving produces, also can make to have big frequency departure between carrier frequency and the local crystal oscillator.Have only fast and effeciently to estimate this frequency departure, just can carry out frequency compensation, reach the frequency departure that receiver can be accepted, thereby carry out next step flow of task.

Based on the frequency offset estimating of demodulating data is technology commonly used in the wireless communication field, in the prior art, smaller based on the scope of the frequency offset estimating of demodulating data.With TD-SCDMA (TD SDMA, Time Division-Synchronous Code Division Multiple Access) QPSK (Quadrature Phase Shift Keying in the system, Quadrature Phase Shift Keying) Tiao Zhi the frequency offset estimating based on demodulating data is an example, its can accurately estimate the maximum magnitude of frequency deviation be about-Fa Hz is to Fa Hz.If the frequency deviation actual value surpasses this scope, mistake will appear.

Summary of the invention

The present invention proposes a kind of method and apparatus that enlarges the frequency offset estimation range of demodulating data, by enlarging the frequency offset estimation range based on demodulating data, can access frequency offset estimating value more accurately.

Technical scheme of the present invention is achieved in that

A kind of method that enlarges the frequency offset estimation range of demodulating data comprises:

First demodulating data is carried out precompensation with at least one first frequency deviation value, obtain at least one second demodulating data;

Calculate at least one second frequency deviation value of described at least one second demodulating data respectively, and according to described second frequency deviation value described second demodulating data is compensated respectively, obtain at least one the 3rd demodulating data;

Phase place dispersion to described at least one the 3rd demodulating data is assessed respectively, determine the 3rd demodulating data of phase place dispersion minimum, and the compensate of frequency deviation value of obtaining the 3rd demodulating data of phase place dispersion minimum is a frequency offset estimation result, wherein, described compensate of frequency deviation value is adding up of described first frequency deviation value and described second frequency deviation value.

Preferably, in described at least one first frequency deviation value one first frequency deviation value being arranged is 0.

Preferably, the phase place dispersion of described at least one the 3rd demodulating data is assessed respectively, is determined that the 3rd demodulating data of phase place dispersion minimum specifically comprises:

Described at least one the 3rd demodulating data is carried out hard decision respectively, obtain at least one first result;

Respectively described the 3rd demodulating data is multiplied each other with corresponding first result's conjugate contraposition, obtain at least one second result;

Calculate described at least one second result's phase variance respectively, and minimum pairing the 3rd demodulating data of definite phase variance is the 3rd demodulating data of phase place dispersion minimum.

Preferably, calculate described at least one second result's phase variance Var respectively according to following formula:

$\mathrm{Var}=\frac{1}{44}*\underset{i=1}{\overset{44}{\mathrm{\Σ}}}{(\arctan \left(\frac{\mathrm{Im}\left(c_i\right)}{\mathrm{Re}\left(c_i\right)}\right)-\mathrm{Mean})}^2;$

Wherein:

$\mathrm{Mean}=\frac{1}{44}*\underset{i=1}{\overset{44}{\mathrm{\Σ}}}\arctan \left(\frac{\mathrm{Im}\left(c_i\right)}{\mathrm{Re}\left(c_i\right)}\right);$

Described c _iRepresent described second result, I _m(c _i) expression c _iImaginary part, R _m(c _i) expression c _iReal part.

Preferably, described at least one second frequency deviation value that calculates described at least one second demodulating data respectively, and according to described second frequency deviation value described second demodulating data is compensated respectively, obtain at least one the 3rd demodulating data and specifically comprise:

Utilize N data symbol in described second demodulating data to carry out frequency offset estimating, obtain the 3rd frequency offset estimating value, wherein, the span of described N is [8*16/SF, 16*16/SF], and SF is a spreading factor;

Utilize described the 3rd frequency offset estimating value that described second demodulating data is carried out compensate of frequency deviation, obtain the 4th demodulating data behind compensate of frequency deviation;

Total data symbol in described the 4th demodulating data of utilization behind compensate of frequency deviation carries out frequency offset estimating, obtains the 4th frequency offset estimating value;

Utilize described the 4th frequency offset estimating value that described the 4th demodulating data is carried out compensate of frequency deviation, obtain the 3rd demodulating data behind compensate of frequency deviation;

Described the 3rd frequency offset estimating value and described the 4th frequency offset estimating value are added up the back as described second frequency deviation value.

A kind of device that enlarges the frequency offset estimation range of demodulating data comprises:

The frequency deviation pre-compensation module is used for by at least one first frequency deviation value first demodulating data being carried out precompensation, obtains at least one second demodulating data;

The frequency offset estimation compensation module is used for calculating respectively at least one second frequency deviation value of described at least one second demodulating data, and according to described second frequency deviation value described second demodulating data is compensated respectively, obtains at least one the 3rd demodulating data;

The phase evaluation module, be used for the phase place dispersion of described at least one the 3rd demodulating data is assessed respectively, determine the 3rd demodulating data of phase place dispersion minimum, and the compensate of frequency deviation value of obtaining the 3rd demodulating data of phase place dispersion minimum is a frequency offset estimation result, wherein, described compensate of frequency deviation value is adding up of described first frequency deviation value and described second frequency deviation value.

Preferably, in described at least one first frequency deviation value one first frequency deviation value being arranged is 0.

Preferably, described phase evaluation module comprises:

Hard judge module is used for described at least one the 3rd demodulating data is carried out hard decision respectively, obtains at least one first result;

Computing module is used for respectively described the 3rd demodulating data is multiplied each other with corresponding first result's conjugate contraposition, obtains at least one second result;

Determination module is used for calculating respectively described at least one second result's phase variance, and minimum pairing the 3rd demodulating data of definite phase variance is the 3rd demodulating data of phase place dispersion minimum;

Acquisition module, the compensate of frequency deviation value that is used to obtain the 3rd demodulating data of phase place dispersion minimum is a frequency offset estimation result, wherein, described compensate of frequency deviation value is adding up of described first frequency deviation value and described second frequency deviation value.

Preferably, described determination module calculates described second result's phase variance Var respectively according to following formula:

$\mathrm{Var}=\frac{1}{44}*\underset{i=1}{\overset{44}{\mathrm{\Σ}}}{(\arctan \left(\frac{\mathrm{Im}\left(c_i\right)}{\mathrm{Re}\left(c_i\right)}\right)-\mathrm{Mean})}^2;$

Wherein:

$\mathrm{Mean}=\frac{1}{44}*\underset{i=1}{\overset{44}{\mathrm{\Σ}}}\arctan \left(\frac{\mathrm{Im}\left(c_i\right)}{\mathrm{Re}\left(c_i\right)}\right);$

Described c _iRepresent described second result, I _m(c _i) expression c _iImaginary part, R _m(c _i) expression c _iReal part.

Preferably, described frequency offset estimation compensation module comprises:

The first frequency offset estimating submodule is used for utilizing N data symbol of described second demodulating data to carry out frequency offset estimating, obtains the 3rd frequency offset estimating value, and wherein, the span of described N is [8*16/SF, 16*16/SF], and SF is a spreading factor;

The first compensation submodule is used to utilize described the 3rd frequency offset estimating value that described second demodulating data is carried out compensate of frequency deviation, obtains the 4th demodulating data behind compensate of frequency deviation;

The second frequency offset estimating submodule is used for utilizing the total data symbol of described the 4th demodulating data behind compensate of frequency deviation to carry out frequency offset estimating, obtains the 4th frequency offset estimating value;

The second compensation submodule is used to utilize described the 4th frequency offset estimating value that described the 4th demodulating data is carried out compensate of frequency deviation, obtains the 3rd demodulating data behind compensate of frequency deviation;

The submodule that adds up is used for described the 3rd frequency offset estimating value and described the 4th frequency offset estimating value are added up the back as described second frequency deviation value.

Technical solution of the present invention is carried out precompensation by at least one frequency deviation value to demodulating data before frequency offset estimating, enlarge the frequency offset estimation range based on demodulating data, thereby can access frequency offset estimating value more accurately.

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.

The schematic flow sheet of method first embodiment of the frequency offset estimation range that Fig. 1 enlarges demodulating data for the present invention is a kind of;

Fig. 2 is the structure of time slot schematic diagram of TD-SCDMA system;

The structural representation of device first embodiment of the frequency offset estimation range that Fig. 3 enlarges demodulating data for the present invention is a kind of.

Embodiment

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

With reference to Fig. 1, show the schematic flow sheet of method first embodiment of a kind of frequency offset estimation range that enlarges demodulating data of the present invention, described method comprises:

Step S110, first demodulating data is carried out precompensation with at least one first frequency deviation value, obtain at least one second demodulating data.

It will be appreciated that each first frequency deviation value in described at least one first frequency deviation value can be unequal, is FaHz as one first frequency deviation value, one first frequency deviation value is FbHz or other.

In addition, described first demodulating data of precompensation should not participated in follow-up computing yet, and therefore, it is 0 that one first frequency deviation value is arranged in described at least one first frequency deviation value, and one in promptly described at least one second demodulating data is described first demodulating data.

Described first demodulating data is carried out precompensation with several first frequency deviation values, just obtain several second demodulating datas behind the precompensation.

Step S120, calculate at least one second frequency deviation value of described at least one second demodulating data respectively, and described second demodulating data is compensated, obtain at least one the 3rd demodulating data according to described second frequency deviation value.

Calculate second frequency deviation value of the described correspondence of each second demodulating data respectively, and compensate according to second demodulating data of second frequency deviation value that calculates to correspondence, the compensation back obtains the 3rd demodulating data.

The method of frequency offset estimating (calculating the frequency deviation value of demodulating data) has multiple, and a kind of frequency deviation estimating method of two-stage cascade is described below.To each second demodulating data at least one second demodulating data, can calculate separately frequency deviation value according to following steps respectively.

The frequency offset estimating of described two-stage cascade comprises:

Step S121, utilize N data symbol in described second demodulating data to carry out frequency offset estimating, obtain the 3rd frequency offset estimating value.

Wherein, the span of described N is [8*16/SF, 16*16/SF], and SF is a spreading factor.

In order effectively to expand the scope of frequency offset estimating, this step uses less data symbol to carry out frequency offset estimating, if the spreading factor SF=16 that system uses, then the preferable range of N is [8,16], promptly get training sequence (Midamble) sign indicating number each 4-8 of both sides data symbol, in the present embodiment, preferably get each 4 data symbol of training sequence code both sides.

Described step S120 is called thick frequency offset estimating, and its detailed process will be described in the embodiment of back.

Step S122, utilize described the 3rd frequency offset estimating value that described second demodulating data is carried out compensate of frequency deviation, obtain the 4th demodulating data behind compensate of frequency deviation.

Total data symbol in step S123, described the 4th demodulating data of utilization behind compensate of frequency deviation carries out frequency offset estimating, obtains the 4th frequency offset estimating value.

Step S124, utilize described the 4th frequency offset estimating value that described the 4th demodulating data is carried out compensate of frequency deviation, obtain the 3rd demodulating data behind compensate of frequency deviation.

Step S125, described the 3rd frequency offset estimating value and described the 4th frequency offset estimating value are added up the back as described second frequency deviation value.

Step S130, the phase place dispersion of described at least one the 3rd demodulating data is assessed respectively, determined the 3rd demodulating data of phase place dispersion minimum.

Phase place dispersion to each the 3rd demodulating data is assessed, and the 3rd demodulating data of definite phase place dispersion minimum.

Wherein, described step S130 comprises:

Step S131, each the 3rd demodulating data is all carried out hard decision, obtain first result of each the 3rd demodulating data correspondence.The specific implementation process of demodulating data being carried out hard decision is exactly that the real part and the imaginary part of demodulation result are only got symbol, and numerical value all becomes 1 or-1.

Step S132, each the 3rd demodulating data is multiplied each other with corresponding hard decision result's (first result) conjugate contraposition, obtain second result of each the 3rd demodulating data correspondence.

Step S133, calculate each second phase variance of correspondence as a result respectively, and minimum pairing the 3rd demodulating data of definite phase variance is the 3rd demodulating data of phase place dispersion minimum.

Wherein, calculate each second result's phase variance Var respectively according to following formula:

$\mathrm{Var}=\frac{1}{44}*\underset{i=1}{\overset{44}{\mathrm{\Σ}}}{(\arctan \left(\frac{\mathrm{Im}\left(c_i\right)}{\mathrm{Re}\left(c_i\right)}\right)-\mathrm{Mean})}^2;$

Wherein:

$\mathrm{Mean}=\frac{1}{44}*\underset{i=1}{\overset{44}{\mathrm{\Σ}}}\arctan \left(\frac{\mathrm{Im}\left(c_i\right)}{\mathrm{Re}\left(c_i\right)}\right);$

Described c _iRepresent described second result, I _m(c _i) expression c _iImaginary part, R _m(c _i) expression c _iReal part.

Step S140, the compensate of frequency deviation value of obtaining the 3rd demodulating data of phase place dispersion minimum are frequency offset estimation result.

The compensate of frequency deviation value that the 3rd demodulating data adopted of phase place dispersion minimum is best frequency offset estimation result.

Wherein, described compensate of frequency deviation value is adding up of described first frequency deviation value and described second frequency deviation value.

Technical solution of the present invention is carried out precompensation by at least one frequency deviation value to demodulating data before frequency offset estimating, enlarge the frequency offset estimation range based on demodulating data, thereby can access frequency offset estimating value more accurately.

In following examples, be example with the QPSK restituted signal that adopts the TD-SCDMA system, other system can be implemented according to the present embodiment technical scheme.

In the TD-SCDMA system, the least unit of demodulating data is a time slot, and the structure of a time slot as shown in Figure 2.

When having a frequency deviation, the data of Data1 are expressed as:

${\tilde{a}}_i=a_i*\exp (-j*2\mathrm{\π\θ}{T}_c\×((22-i)*\mathrm{SF}+72+8)),i=\mathrm{1,2},...,22;$

The data of Data2 are expressed as:

${\tilde{a}}_i=a_i*\exp (-j*2\mathrm{\π\θ}{T}_c\×((i-22)*\mathrm{SF}+72+8)),i=22,24,...,43;$

Wherein, a _iBe the data of no frequency deviation,

Be the data that have frequency deviation, T _cBe spreading rate, its value equals

θ is a frequency deviation value, and SF is a spreading factor.

The implementation process of technical solution of the present invention is as follows:

S1, in the FD-SCDMA system, adopt the QPSK modulation system, be approximately [Fa, Fa] Hz based on the maximum magnitude of the frequency offset estimating of demodulating data.In order to enlarge frequency offset estimation range, earlier data after demodulating is carried out precompensation, can be earlier to demodulating data compensation-FbHz frequency deviation and FbHz frequency deviation, wherein, preferred Fb＜2 * Fa is after the data of compensation-FbHz frequency deviation, the frequency deviation region that can be estimated is [Fa-Fb, Fa-Fb] Hz; After the data of compensation FbHz frequency deviation, the scope that can be estimated is [Fa+Fb, Fa+Fb] Hz; The data that do not have the precompensation frequency deviation can be estimated the scope that and are [Fa, Fa].Thereby the scope of frequency offset estimating just can be extended to [Fa-Fb, Fa+Fb] Hz, and it should be noted that: in order to prevent The noise, can keep certain lap between each scope, in this example, lap is Dz=(2 * Fa-Fb) Hz.Compensation is implemented according to following formula:

Data to Data1:

${\hat{b}}_i=b_i*\exp (j*2\mathrm{\π}{f}_a{T}_c\×((N/2-i)*\mathrm{SF}+72+8)),i=\mathrm{1,2},...,22;$

Data to Data2:

${\hat{b}}_i=b_i*\exp (-j*2\mathrm{\π}{f}_a{T}_c\×((i-N/2)*\mathrm{SF}+72+8)),i=\mathrm{22,24},...,43.$

Wherein, f _aBe frequency deviation value, b _iBe the data after the demodulation,

Be the result who the data after the demodulation is carried out compensate of frequency deviation.T _cBe spreading rate, its value equals

S2, the data after the S1 step compensation are carried out frequency offset estimating and compensation respectively.A kind of frequency deviation estimating method of two-stage cascade is described below.Because produce three groups of data (data after one group of uncompensated data and the two groups of compensation) in the S1 step, therefore, to each group data, S2-1 to S2-5 will be performed once, carries out altogether three times.

S2-1, thick frequency offset estimating.Earlier with Data1 and Data2 part, participate in thick frequency offset estimating near N data of training sequence midamble sign indicating number part, described N is preferred 4, and is as follows:

S2-1-1, demodulation result is carried out hard decision, concrete implementation step is exactly that the real part and the imaginary part of demodulation result are only got symbol, and numerical value all becomes 1 or-1.In this step, the data of processing are 4 data of the most close midamble sign indicating number of Data1 and 4 data of the most close midamble sign indicating number of Data2.

S2-1-2, the conjugate contraposition of declaring the result firmly in demodulation result and the S2-1-1 step is multiplied each other, make demodulation result transfer to the first quartile of planisphere.In this step, the data of processing are 4 data of the most close midamble sign indicating number of Data1 and 4 data of the most close midamble sign indicating number of Data2.

The conjugate contraposition of the data of S2-1-3, the data of Data2 that will transfer to QPSK modulation system first quartile and Data1 is multiplied each other, and multiplied result is added up.In this step, the data of use are 4 data of the most close midamble sign indicating number of Data1 and 4 data of the most close midamble sign indicating number of Data2.

S2-1-4, calculate frequency deviation value according to the result of S2-1-3, computing formula is as follows:

$f_{\mathrm{offset}}=\arctan \left(\frac{\mathrm{Im}\left(C\right)}{\mathrm{Re}\left(C\right)}\right)/\left(2\mathrm{\π}{T}_c(N*\mathrm{SF}+144)\right)$

Wherein, C is the result that step S2-1-3 calculates, and N is an employed symbolic number during the S2-1-3 step is calculated, T _cBe spreading rate, its value equals

SF is a spreading factor, and in the S2-1 step, N gets 4.

S2-2, thick frequency offset estimation result compensate of frequency deviation.Data after the compensation in the S1 step are carried out compensate of frequency deviation according to the result of S2-1 frequency offset estimating, and compensation is implemented according to the formula among the S1, it should be noted that this step is that data to all Data1 and Data2 compensate.

S2-3, smart frequency offset estimating.Result to S2-2 carries out frequency offset estimating once more, and in S2-3, all symbols participate in estimating that it is identical with the S2-1 step to implement principle.Different with S2-1 is, at step S2-1-1, S2-1-2, S2-1-3 use the data of all Data1 and Data2, and N gets 22 in step S2-1-4.

S2-4, smart frequency offset estimation result compensate of frequency deviation.Data after the S2-2 step compensation are carried out compensate of frequency deviation according to the result of S2-3 frequency offset estimating, and compensation is implemented according to the formula among the S1, also is that the data to all Data1 and Data2 compensate in this step.

S2-5, total frequency offset calculation.With the thick frequency offset estimating value in the frequency deviation pre-compensation value in the S1 step, the S2-1 step, the smart frequency offset estimating value in the S2-3 step adds up, and obtains the total frequency offset estimation result for demodulating data.

S3, the phase place dispersion of each result after the S2 step compensation is assessed, and data are optimum after the compensation of judgement phase place dispersion minimum that the offset that it adopted is best frequency offset estimation result.

S3-1, at first need carry out phase evaluation to each result of S2 step, and the process of phase evaluation is as follows:

S3-1-1, demodulation result is carried out hard decision, concrete implementation step is exactly that the real part and the imaginary part of demodulation result are only got symbol, and numerical value all becomes 1 or-1.

S3-1-2, the conjugate contraposition of declaring the result firmly of demodulation result and S3-1-1 is multiplied each other.

S3-1-3, calculating S3-1-2 result's phase variance, computing formula is as follows:

Average: $\mathrm{Mean}=\frac{1}{44}*\underset{i=1}{\overset{44}{\mathrm{\Σ}}}\arctan \left(\frac{\mathrm{Im}\left(c_i\right)}{\mathrm{Re}\left(c_i\right)}\right);$

Variance: $\mathrm{Var}=\frac{1}{44}*\underset{i=1}{\overset{44}{\mathrm{\Σ}}}{(\arctan \left(\frac{\mathrm{Im}\left(c_i\right)}{\mathrm{Re}\left(c_i\right)}\right)-\mathrm{Mean})}^2.$

Described c _iRepresent the result that calculates in the described S3-1-2 step, I _m(c _i) expression c _iImaginary part, R _m(c _i) expression c _iReal part.

S3-2, choose variance Var minimum in the S3-1 step pairing demodulation result as final result, the frequency deviation value that compensated is as the compensate of frequency deviation value that estimates.

With reference to Fig. 3, show the structural representation of device first embodiment of a kind of frequency offset estimation range that enlarges demodulating data of invention.Described device comprises:

The frequency deviation pre-compensation module is used for by at least one first frequency deviation value first demodulating data being carried out precompensation, obtains at least one second demodulating data.

The frequency offset estimation compensation module is used for calculating respectively at least one second frequency deviation value of described at least one second demodulating data, and according to described second frequency deviation value described second demodulating data is compensated respectively, obtains at least one the 3rd demodulating data.

The phase evaluation module, be used for the phase place dispersion of described at least one the 3rd demodulating data is assessed respectively, determine the 3rd demodulating data of phase place dispersion minimum, and the compensate of frequency deviation value of obtaining the 3rd demodulating data of phase place dispersion minimum is a frequency offset estimation result, wherein, described compensate of frequency deviation value is adding up of described first frequency deviation value and described second frequency deviation value.

Wherein, in described at least one first frequency deviation value one first frequency deviation value being arranged is 0.

Wherein, described phase evaluation module comprises:

Hard judge module is used for described at least one the 3rd demodulating data is carried out hard decision respectively, obtains at least one first result;

Computing module is used for respectively described the 3rd demodulating data is multiplied each other with corresponding first result's conjugate contraposition, obtains at least one second result;

Determination module is used for calculating respectively described at least one second result's phase variance, and minimum pairing the 3rd demodulating data of definite phase variance is the 3rd demodulating data of phase place dispersion minimum;

Acquisition module, the compensate of frequency deviation value that is used to obtain the 3rd demodulating data of phase place dispersion minimum is a frequency offset estimation result, wherein, described compensate of frequency deviation value is adding up of described first frequency deviation value and described second frequency deviation value.

Described determination module calculates described second result's phase variance Var respectively according to following formula:

$\mathrm{Var}=\frac{1}{44}*\underset{i=1}{\overset{44}{\mathrm{\Σ}}}{(\arctan \left(\frac{\mathrm{Im}\left(c_i\right)}{\mathrm{Re}\left(c_i\right)}\right)-\mathrm{Mean})}^2;$

Wherein:

$\mathrm{Mean}=\frac{1}{44}*\underset{i=1}{\overset{44}{\mathrm{\Σ}}}\arctan \left(\frac{\mathrm{Im}\left(c_i\right)}{\mathrm{Re}\left(c_i\right)}\right);$

Described c _iRepresent described second result, I _m(c _i) expression c _iImaginary part, R _m(c _i) expression c _iReal part.

Wherein, described frequency offset estimation compensation module comprises:

The first frequency offset estimating submodule is used for utilizing N data symbol of described second demodulating data to carry out frequency offset estimating, obtains the 3rd frequency offset estimating value, and wherein, the span of described N is [8*16/SF, 16*16/SF], and SF is a spreading factor;

The first compensation submodule is used to utilize described the 3rd frequency offset estimating value that described second demodulating data is carried out compensate of frequency deviation, obtains the 4th demodulating data behind compensate of frequency deviation;

The second frequency offset estimating submodule is used for utilizing the total data symbol of described the 4th demodulating data behind compensate of frequency deviation to carry out frequency offset estimating, obtains the 4th frequency offset estimating value;

The second compensation submodule is used to utilize described the 4th frequency offset estimating value that described the 4th demodulating data is carried out compensate of frequency deviation, obtains the 3rd demodulating data behind compensate of frequency deviation;

The submodule that adds up is used for described the 3rd frequency offset estimating value and described the 4th frequency offset estimating value are added up the back as described second frequency deviation value.

Technical solution of the present invention is carried out precompensation by at least one frequency deviation value to demodulating data before frequency offset estimating, enlarge the frequency offset estimation range based on demodulating data, thereby can access frequency offset estimating value more accurately.

One of ordinary skill in the art will appreciate that; in each method embodiment of the present invention; the sequence number of described each step can not be used to limit the sequencing of each step; for those of ordinary skills; under the prerequisite of not paying creative work, the priority of each step is changed also within protection scope of the present invention.

The above only is preferred embodiment of the present invention, and is in order to restriction the present invention, within the spirit and principles in the present invention not all, any modification of being done, is equal to replacement, improvement etc., all should be included within protection scope of the present invention.

Claims (10)

1. a method that enlarges the frequency offset estimation range of demodulating data is characterized in that, comprising:

First demodulating data is carried out precompensation with at least one first frequency deviation value, obtain at least one second demodulating data;

Calculate at least one second frequency deviation value of described at least one second demodulating data respectively, and according to described second frequency deviation value described second demodulating data is compensated respectively, obtain at least one the 3rd demodulating data;

Phase place dispersion to described at least one the 3rd demodulating data is assessed respectively, determine the 3rd demodulating data of phase place dispersion minimum, and the compensate of frequency deviation value of obtaining the 3rd demodulating data of phase place dispersion minimum is a frequency offset estimation result, wherein, described compensate of frequency deviation value is adding up of described first frequency deviation value and described second frequency deviation value.

2. the method for the frequency offset estimation range of expansion demodulating data according to claim 1 is characterized in that, it is 0 that one first frequency deviation value is arranged in described at least one first frequency deviation value.

3. the method for the frequency offset estimation range of expansion demodulating data according to claim 2 is characterized in that, the phase place dispersion of described at least one the 3rd demodulating data is assessed respectively, determines that the 3rd demodulating data of phase place dispersion minimum specifically comprises:

Described at least one the 3rd demodulating data is carried out hard decision respectively, obtain at least one first result;

Respectively described the 3rd demodulating data is multiplied each other with corresponding first result's conjugate contraposition, obtain at least one second result;

Calculate described at least one second result's phase variance respectively, and minimum pairing the 3rd demodulating data of definite phase variance is the 3rd demodulating data of phase place dispersion minimum.

4. the method for the frequency offset estimation range of expansion demodulating data according to claim 3 is characterized in that, calculates described at least one second result's phase variance Var respectively according to following formula:

$\mathrm{Var}=\frac{1}{44}*\underset{i=1}{\overset{44}{\mathrm{\Σ}}}{(\arctan \left(\frac{\mathrm{Im}\left(c_i\right)}{\mathrm{Re}\left(c_i\right)}\right)-\mathrm{Mean})}^2;$

Wherein:

$\mathrm{Mean}=\frac{1}{44}*\underset{i=1}{\overset{44}{\mathrm{\Σ}}}\arctan \left(\frac{\mathrm{Im}\left(c_i\right)}{\mathrm{Re}\left(c_i\right)}\right);$

Described c _iRepresent described second result, I _m(c _i) expression c _iImaginary part, R _m(c _i) expression c _iReal part.

5. according to the method for the frequency offset estimation range of each described expansion demodulating data of claim 1 to 4, it is characterized in that, described at least one second frequency deviation value that calculates described at least one second demodulating data respectively, and according to described second frequency deviation value described second demodulating data is compensated respectively, obtain at least one the 3rd demodulating data and specifically comprise:

Utilize N data symbol in described second demodulating data to carry out frequency offset estimating, obtain the 3rd frequency offset estimating value, wherein, the span of described N is [8*16/SF, 16*16/SF], and SF is a spreading factor;

Utilize described the 3rd frequency offset estimating value that described second demodulating data is carried out compensate of frequency deviation, obtain the 4th demodulating data behind compensate of frequency deviation;

Total data symbol in described the 4th demodulating data of utilization behind compensate of frequency deviation carries out frequency offset estimating, obtains the 4th frequency offset estimating value;

Utilize described the 4th frequency offset estimating value that described the 4th demodulating data is carried out compensate of frequency deviation, obtain the 3rd demodulating data behind compensate of frequency deviation;

Described the 3rd frequency offset estimating value and described the 4th frequency offset estimating value are added up the back as described second frequency deviation value.

6. a device that enlarges the frequency offset estimation range of demodulating data is characterized in that, comprising:

The frequency deviation pre-compensation module is used for by at least one first frequency deviation value first demodulating data being carried out precompensation, obtains at least one second demodulating data;

The frequency offset estimation compensation module is used for calculating respectively at least one second frequency deviation value of described at least one second demodulating data, and according to described second frequency deviation value described second demodulating data is compensated respectively, obtains at least one the 3rd demodulating data;

The phase evaluation module, be used for the phase place dispersion of described at least one the 3rd demodulating data is assessed respectively, determine the 3rd demodulating data of phase place dispersion minimum, and the compensate of frequency deviation value of obtaining the 3rd demodulating data of phase place dispersion minimum is a frequency offset estimation result, wherein, described compensate of frequency deviation value is adding up of described first frequency deviation value and described second frequency deviation value.

7. the device of the frequency offset estimation range of expansion demodulating data according to claim 6 is characterized in that, it is 0 that one first frequency deviation value is arranged in described at least one first frequency deviation value.

8. the device of the frequency offset estimation range of expansion demodulating data according to claim 7 is characterized in that, described phase evaluation module comprises:

Hard judge module is used for described at least one the 3rd demodulating data is carried out hard decision respectively, obtains at least one first result;

Computing module is used for respectively described the 3rd demodulating data is multiplied each other with corresponding first result's conjugate contraposition, obtains at least one second result;

Determination module is used for calculating respectively described at least one second result's phase variance, and minimum pairing the 3rd demodulating data of definite phase variance is the 3rd demodulating data of phase place dispersion minimum;

Acquisition module, the compensate of frequency deviation value that is used to obtain the 3rd demodulating data of phase place dispersion minimum is a frequency offset estimation result, wherein, described compensate of frequency deviation value is adding up of described first frequency deviation value and described second frequency deviation value.

9. the device of the frequency offset estimation range of expansion demodulating data according to claim 8 is characterized in that, described determination module calculates described second result's phase variance Var respectively according to following formula:

$\mathrm{Var}=\frac{1}{44}*\underset{i=1}{\overset{44}{\mathrm{\Σ}}}{(\arctan \left(\frac{\mathrm{Im}\left(c_i\right)}{\mathrm{Re}\left(c_i\right)}\right)-\mathrm{Mean})}^2;$

Wherein:

$\mathrm{Mean}=\frac{1}{44}*\underset{i=1}{\overset{44}{\mathrm{\Σ}}}\arctan \left(\frac{\mathrm{Im}\left(c_i\right)}{\mathrm{Re}\left(c_i\right)}\right);$

Described c _iRepresent described second result, I _m(c _i) expression c _iImaginary part, R _m(c _i) expression c _iReal part.

10. according to the device of the frequency offset estimation range of each described expansion demodulating data of claim 6 to 9, it is characterized in that described frequency offset estimation compensation module comprises:

The first frequency offset estimating submodule is used for utilizing N data symbol of described second demodulating data to carry out frequency offset estimating, obtains the 3rd frequency offset estimating value, and wherein, the span of described N is [8*16/SF, 16*16/SF], and SF is a spreading factor;

The first compensation submodule is used to utilize described the 3rd frequency offset estimating value that described second demodulating data is carried out compensate of frequency deviation, obtains the 4th demodulating data behind compensate of frequency deviation;

The second frequency offset estimating submodule is used for utilizing the total data symbol of described the 4th demodulating data behind compensate of frequency deviation to carry out frequency offset estimating, obtains the 4th frequency offset estimating value;

The second compensation submodule is used to utilize described the 4th frequency offset estimating value that described the 4th demodulating data is carried out compensate of frequency deviation, obtains the 3rd demodulating data behind compensate of frequency deviation;

The submodule that adds up is used for described the 3rd frequency offset estimating value and described the 4th frequency offset estimating value are added up the back as described second frequency deviation value.