CN102594740B - Method and device for estimating frequency offset - Google Patents

Abstract

The invention discloses a frequency offset estimation method and a device, so as to improve the efficiency and accuracy of the frequency offset estimation and reduce the implementation complexity. The method is as follows: receiving the transmission signal of the mobile terminal, calculating the accurate channel estimation value corresponding to each subcarrier carrying the transmission signal, respectively calculating the power value of the corresponding subcarrier based on each accurate channel estimation value, and determining the division in the system Resource blocks, each resource block contains a specified number of subcarriers, and according to the power value corresponding to each subcarrier, select the target resource block, respectively according to the accurate channel estimation value of each subcarrier in the target resource block, and for each subcarrier The preset reference symbols are used to calculate the frequency offset of the service data symbols included in each subcarrier, and to perform frequency offset compensation on the service data symbols according to the frequency offset of the service data symbols corresponding to each subcarrier. The invention also discloses a frequency offset estimation device.

Description

A frequency offset estimation method and device

technical field

The present invention relates to the communication field, in particular to a frequency offset estimation method and device.

Background technique

In a wireless communication system, for a multi-carrier system, the offset of the carrier frequency will cause interference between channels, especially in an Orthogonal Frequency Division Multiplexing (OFDM) system, which requires strict synchronization between subcarriers, and the carrier frequency The impact brought by the offset (hereinafter referred to as frequency offset) will be more serious. In practical applications, in more complex time-varying wireless channels, there are situations such as frequency deviation between the transmitter carrier and the receiver local oscillator or Doppler frequency shift due to fast movement, which will seriously damage Orthogonality between subcarriers in OFDM system causes interference. The OFDM technology is adopted in the fourth-generation mobile communication system LTE, which requires relatively accurate frequency offset estimation to effectively eliminate inter-carrier interference.

The frequency offset estimation method of the traditional OFDM system mostly uses correlation calculations for OFDM symbols in the time domain or frequency domain, and calculates the phase after continuous accumulation to estimate the frequency offset. This requires some parameters and conditions and certain changes. Among them, the frequency domain autocorrelation algorithm is divided into two stages: coarse estimation and fine estimation. The frequency offset estimation range and estimation variance are determined by the interval of autocorrelation. The smaller the interval, the larger the estimation range and estimation variance, and the larger the interval. The smaller the estimation range and the estimation variance, in the process of rough estimation and fine estimation, it is necessary to select a suitable interval to seek a large estimation range and a small estimation variance, which requires finding the optimal autocorrelation interval, which is difficult to implement , at the same time, switching back and forth between coarse estimation and fine estimation also increases the complexity of subcarrier synchronization; while the premise of time-domain autocorrelation is to accurately time-synchronize the two parametric symbols in the time slot, if there is a slight deviation, the phase angle obtained after autocorrelation will carry the information of the rest of the service data, resulting in a large error in the frequency offset estimation. In the LTE system, the base station receives the time domain data, and then converts the data to Subsequent processing in the frequency domain cannot guarantee accurate synchronization in the time domain in advance, so the use of time domain autocorrelation for frequency offset estimation cannot be guaranteed. At the same time, the inverse Fourier transform IFFT is required to convert from the frequency domain to the time domain. It takes a lot of time and increases the complexity of the circuit.

Contents of the invention

The present invention provides a frequency offset estimation method and device, which are used to improve the efficiency and accuracy of frequency offset estimation, reduce the resources consumed by the system, and reduce the complexity of hardware implementation.

The specific technical scheme that the embodiment of the present invention provides is as follows:

A frequency offset estimation method, comprising:

Receiving the transmission signal of the mobile terminal, respectively calculating the accurate channel estimation value corresponding to each subcarrier carrying the transmission signal;

Calculating power values of corresponding subcarriers based on the obtained accurate channel estimation values;

Determine the divided resource blocks in the system, where each resource block contains a specified number of subcarriers, and select a target resource block according to the power value corresponding to each subcarrier;

Calculate the estimated frequency offset of the service data symbols contained in each subcarrier according to the accurate channel estimation value of each subcarrier in the target resource block and the reference symbol preset for each subcarrier;

Frequency adjustment is performed on the service data symbols according to the estimated frequency offset of the service data symbols corresponding to each subcarrier.

A frequency offset estimation device, comprising:

The precise channel estimation module is used to receive the transmission signal of the mobile terminal, and respectively calculate the precise channel estimation value corresponding to each subcarrier carrying the transmission signal;

A power calculation module, configured to calculate power values of corresponding subcarriers based on the obtained accurate channel estimation values;

The resource block selection module is used to determine the divided resource blocks in the system, wherein each resource block contains a specified number of subcarriers, and selects the target resource block according to the power value corresponding to each subcarrier;

A frequency offset estimation module, configured to calculate the estimated frequency offset of the service data symbols contained in each subcarrier according to the accurate channel estimation value of each subcarrier in the target resource block and the reference symbols preset for each subcarrier;

The adjustment module is configured to adjust the frequency of the service data symbols according to the estimated frequency offset of the service data symbols corresponding to each subcarrier.

Based on the above technical solution, by obtaining the accurate channel estimation value of each subcarrier, the power value of the corresponding subcarrier is calculated respectively, and the target resource block is selected according to the power value corresponding to each subcarrier. The channel estimation value calculates the estimated frequency offset of the service data symbols included in each subcarrier through the set reference symbols, and adjusts the frequency of the service data symbols according to the estimated frequency offset of the service data symbols corresponding to each subcarrier. Therefore, the efficiency and accuracy of frequency offset estimation can be effectively improved, the resources consumed by the system can be reduced, and the complexity of hardware implementation can be reduced.

Description of drawings

FIG. 1 is an architecture diagram of the frequency offset estimation system of the present invention;

FIG. 2 is a structural diagram of a frequency offset estimation device of the present invention;

FIG. 3 is a flow chart of the frequency offset estimation method of the present invention;

Fig. 4 is the structural representation of data frame of the present invention;

Fig. 5 is a schematic diagram of the time-frequency structure of the present invention.

detailed description

In order to improve the efficiency and accuracy of frequency offset estimation, reduce the resources consumed by the system, and reduce the complexity of hardware implementation, the embodiment of the present invention provides a frequency offset estimation method and device, which can effectively improve the efficiency and accuracy of frequency offset estimation degree, and reduce the resources consumed by the system, and reduce the complexity of hardware implementation. The method is as follows: receiving the transmission signal of the mobile terminal, calculating the accurate channel estimation value corresponding to each subcarrier carrying the transmission signal, respectively calculating the power value of the corresponding subcarrier based on the obtained accurate channel estimation value, and determining the power value of the corresponding subcarrier in the system. The divided resource blocks, wherein each resource block contains a specified number of subcarriers, and according to the power value corresponding to each subcarrier, select the target resource block, respectively according to the accurate channel estimation value of each subcarrier in the target resource block, and For the preset reference symbols of each subcarrier, calculate the estimated frequency offset of the service data symbols contained in each subcarrier, and adjust the frequency of the service data symbols according to the estimated frequency offset of the service data symbols corresponding to each subcarrier.

Preferred embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings.

The method provided by the embodiment of the present invention can be applied to various OFDM systems. In the following embodiments, only the LTE system is used as an example for illustration.

Referring to Figure 1, in the embodiment of the present invention, the frequency offset estimation system is mainly composed of a frequency offset estimation device 10 and a mobile terminal 11, wherein,

The frequency offset estimating device 10 is configured to receive the transmission signal of the mobile terminal 11, respectively calculate the accurate channel estimation value corresponding to each subcarrier carrying the transmission signal, and respectively calculate the power value of the corresponding subcarrier based on each obtained accurate channel estimation value , determine the divided resource blocks in the system, where each resource block contains a specified number of subcarriers, and select the target resource block according to the power value corresponding to each subcarrier, and respectively according to the precise value of each subcarrier in the target resource block The channel estimation value, and the reference symbol preset for each subcarrier, calculate the frequency offset estimation value of the service data symbol contained in each subcarrier, and calculate the service data symbol according to the frequency offset estimation value of the service data symbol corresponding to each subcarrier make frequency adjustments;

The mobile terminal 11 is configured to send a signal to the base station, so as to perform rough channel estimation according to the signal.

Referring to shown in accompanying drawing 2, in the embodiment of the present invention, frequency offset estimation device 10 is mainly made up of following modules:

The accurate channel estimation module 101 is used to receive the transmission signal of the mobile terminal, and respectively calculate the accurate channel estimation value corresponding to each subcarrier carrying the transmission signal;

A power calculation module 102, configured to calculate power values of corresponding subcarriers based on the obtained accurate channel estimation values;

A resource block selection module 103, configured to determine divided resource blocks in the system, wherein each resource block contains a specified number of subcarriers, and select a target resource block according to the power value corresponding to each subcarrier;

The frequency offset estimation module 104 is configured to calculate the estimated frequency offset of the service data symbols contained in each subcarrier according to the accurate channel estimation value of each subcarrier in the target resource block and the reference symbols preset for each subcarrier ;

The adjusting module 105 is configured to adjust the frequency of the service data symbols according to the estimated frequency offset of the service data symbols corresponding to each subcarrier.

Referring to the accompanying drawing 3, in the embodiment of the present invention, the detailed flow of the frequency offset estimation method is as follows:

Step 301: Receive a transmission signal from a mobile terminal, and respectively calculate accurate channel estimation values corresponding to each subcarrier carrying the transmission signal.

Receive the transmission signal of the mobile terminal, and calculate the precise channel estimation value corresponding to each subcarrier carrying the transmission signal, specifically: receive the transmission signal of the mobile terminal, obtain the rough channel estimation value of each subcarrier according to the transmission signal, and calculate each subcarrier After multiplying and accumulating the rough channel estimation value of N subcarriers and the rough channel estimation value of N subcarriers, the phase angle is calculated and the overall time offset value of the mobile terminal is obtained; using the obtained overall time offset value, the time offset of each subcarrier is calculated, And according to the time offset of each subcarrier, the time offset compensation is correspondingly performed on the rough channel estimation value of each subcarrier, so as to obtain the precise channel estimation value with the time offset eliminated.

Wherein, the signal sent by the mobile terminal received by the base station is a local predictive signal, and the base station receives the foregoing predictive signal sent by the mobile terminal, and performs rough channel estimation based on the predictive signal. Preferably, a least square (Least Square, LS) channel estimation method can be used for rough channel estimation.

For example, referring to Figure 4, in the LTE system, the mobile terminal sends signals in the form of data frames, each data frame includes 10 subframes, each subframe includes two time slots, and each time slot can be Including 6 or 7 OFDM symbols, in the embodiment of the present invention, a reference symbol is preset in the middle of each subframe, and the rest of each subframe is service data symbols. The least square (LS) channel estimation method can be used for rough channel estimation, specifically: after the base station receives and demodulates the predicted signal sent by the mobile terminal, for each subcarrier carrying the demodulated signal, the demodulated The signal and the conjugate of the predicted signal are dot-multiplied to obtain the rough channel estimation value of each subcarrier respectively. Wherein, the LS rough channel estimation is performed for each subcarrier corresponding to the reference symbols of two time slots in each subframe.

Among them, after multiplying and accumulating the rough channel estimation value of each subcarrier by the rough channel estimation value of N subcarriers, the phase angle is calculated and the overall time offset value of the mobile terminal is obtained, specifically: the rough channel estimation value of each subcarrier Calculate the phase angle after multiplying and accumulating the estimated value and the rough channel estimation value separated by N subcarriers, preferably N is 6, the phase angle is the overall time offset value of the mobile terminal, and then divide the calculated phase angle by N is to obtain the time offset value of each subcarrier of the mobile terminal, and the calculation formula can be expressed as Among them, t ₀ represents the time offset value of the mobile terminal in the time slot, H _LS (k) represents the rough channel estimation value of the kth subcarrier, conj(H _LS (k+N)) represents the k+Nth subcarrier The conjugate of the rough channel estimation value of , M represents the total number of subcarriers of the mobile terminal.

In the embodiment of the present invention, after the rough channel estimation value of each subcarrier is multiplied and accumulated by the rough channel estimation value of N subcarriers, the following method can be used to calculate the phase angle: perform approximate calculation, and calculate the phase angle through the arctangent function , firstly, after taking the first-order derivative of the _arctangent function, according to Taylor's formula, there is where f(x ₀ )=arctan(x ₀ ). In the embodiment of the present invention, three lookup tables are preset to quickly calculate the phase angle f(x), wherein, by looking up the value of x ₀ preset in table 1, the value of arctan(x ₀ ) preset in lookup table 2 , look up the preset in Table 3 The values of the three tables are in one-to-one correspondence. For example, the value corresponding to the 10th row in the lookup table 1 corresponds to the value of the 10th row in the lookup tables 2 and 3, that is, the phase angle f(x) =LUT(index, 2)+LUT(index, 3)·(x-LUT(index, 1)), wherein LUT(index, 1) represents the value corresponding to the index row of lookup table 1, LUT(index, 2 ), LUT(index, 3) are similar to it.

Among them, according to the time offset of each subcarrier, the rough channel estimate of each subcarrier is correspondingly compensated for time offset to obtain an accurate channel estimate with time offset eliminated, and the calculation formula is H(k) represents the accurate channel estimation value after removing the time offset, and k represents the kth carrier.

Step 302: Calculate power values of corresponding subcarriers based on the obtained precise channel estimation values.

According to the accurate channel estimation value H(k) of each subcarrier, the power value of each subcarrier is calculated, and the calculation formula is expressed as: P=H(k)·conj(H(k))=real ² (H(k)) +imag ² (H(k)), P represents the power value of the subcarrier, real ² (H(k)) represents the square of the real part of the precise channel estimate, imag ² (H(k)) represents the imaginary part of the precise channel estimate Ministry square.

Step 303: Determine divided resource blocks in the system, where each resource block contains a specified number of subcarriers, and select a target resource block according to the power value corresponding to each subcarrier.

The resource blocks divided by different systems are not the same, and the number of subcarriers contained in each resource block is also different. For example, for the LTE system, each resource block contains 12 subcarriers, and each mobile terminal corresponds to 10 subcarriers. resource blocks.

The target resource block refers to the optimal resource block, that is, the channel with the best fading condition is selected as a representative among the large fading channels (minimum power value). In the embodiment of the present invention, channel selection is performed in units of resource blocks, and the minimum power value is selected in each resource block as the representative power of the resource block to represent channel fading.

Wherein, the target resource block is selected according to the power value corresponding to each subcarrier, specifically: according to the power value corresponding to each subcarrier, the minimum subcarrier power value in each resource block is selected respectively; The minimum subcarrier power value is compared, and the maximum subcarrier power value of each subframe is selected therefrom, and the resource block corresponding to the maximum subcarrier power value is used as the target resource block.

In the embodiment of the present invention, when the resource block corresponding to the maximum subcarrier power value is used as the target resource block, the subframe contained in the subcarrier corresponding to the maximum subcarrier power value is first determined, and the first time slot reference symbol of the above subframe is The resource block corresponding to the location is used as the target resource block of the subframe, that is, the target resource block is used as the target resource block corresponding to the second time slot reference symbol of the subframe at the same time.

Step 304: According to the accurate channel estimation value of each subcarrier in the target resource block and the reference symbols preset for each subcarrier, calculate the frequency offset estimation value of the service data symbols included in each subcarrier.

According to the nature of the Fourier transform, the frequency domain offset appears as a phase angle change in the time domain. Therefore, it is only necessary to transform the accurate channel estimation of the two time slots of the subframe in the frequency domain into the time domain, and calculate the time domain The phase angle, through the change of the phase angle, the frequency offset of each subcarrier carrying the subframe can be known.

This step is specifically: according to the accurate channel estimation value of each subcarrier in the target resource block and the reference symbol preset for each subcarrier, respectively calculate the value of the time domain zero point corresponding to the accurate channel estimation value of each subcarrier, and Calculate the estimated frequency offset value at the reference symbol corresponding to the target resource block based on the value of the zero point in the time domain; respectively make a difference between the estimated frequency offset values at the two reference symbols continuously obtained on each subcarrier in the target resource block , obtain the estimated frequency offset between the two reference symbols on the above subcarriers, and calculate the frequency offset of the service data symbols contained in the corresponding subcarriers based on the estimated frequency offset between the two reference symbols on each subcarrier. Frequency offset estimate.

Preferably, when calculating the value of the zero point in the time domain corresponding to each subcarrier's accurate channel estimation value, each subcarrier's accurate channel estimation value is transformed into the time domain through inverse Fourier transform, and the front The average value of the accurate channel estimation values of sub-carriers that is an exponential multiple of 2 is approximately the value of the zero point in the time domain. Since the accurate channel estimation of each subcarrier on the resource block is in the form of a truncated function (such as a window function), the form after converting it to the time domain is sync(x)=sin x/x, most of which The energy is concentrated in the main lobe (that is, near the zero point), and the value of the zero point in the time domain can be directly selected for phase angle calculation.

According to the formula of the inverse Fourier transform It can be seen that the value of the zero point in the time domain is expressed as Here X(k) is the accurate channel estimation value H(K), N is the number of subcarriers contained in the resource block, preferably, N is an exponential multiple of 2, and then calculate the phase angle corresponding to the resource block

For example, in the LTE system, a resource block contains 12 subcarriers. For the convenience of hardware implementation, the average value of the accurate channel estimation values of the first 8 subcarriers is taken as the value of the zero point in the time domain, expressed as then the phase angle

For the reference symbols of two time slots of the same subframe that are continuously obtained on each subcarrier in the target resource block, the phase angles corresponding to the reference symbols of each time slot are calculated according to the above steps, and respectively obtained Since the base station is a multi-antenna system, the average of the phase angle values of multiple antennas can be calculated, and the obtained average values are respectively used as the final phase angle values of the reference symbols of each time slot corresponding to the above subframe. After calculating the phase angle of the reference symbol of each time slot, subtract the phase angle corresponding to the previous time slot from the phase angle corresponding to the next time slot, that is, to obtain two consecutive time slot reference symbols obtained on each subcarrier in the target resource block in the frequency domain. The frequency offset between symbols is controlled by adding or subtracting 2π to control the frequency offset between the above reference symbols within the range of plus or minus π, and further based on the frequency offset between two reference symbols on each subcarrier to obtain the corresponding subcarrier The frequency offset of the included traffic data symbols.

Preferably, when the frequency offset of the service data symbols contained in the corresponding subcarriers is obtained based on the frequency offset between the reference symbols on each subcarrier, it is marked that there is no frequency offset at the first reference symbol, based on two Calculate the frequency offset between two reference symbols The frequency offset between adjacent OFDM symbols obtained continuously by corresponding subcarriers, based on the frequency offset between adjacent OFDM symbols, perform linear interpolation to calculate the service data symbols contained in the corresponding subcarriers frequency offset between.

For example, referring to Figure 5, it is assumed that in the LTE system, each time slot contained in a subframe consists of 7 OFDM symbols, and the symbols located in the middle of each time slot are set as reference symbols, and the rest are service data symbols, That is, the fourth symbol of each time slot is a reference symbol, and the reference symbols of two time slots are separated by 6 service data symbols. After the target resource block is selected, the frequency offset estimation value at the two timeslot reference symbols obtained continuously by each subcarrier in the target resource block is made to be different, that is, the phase angle at the second time slot reference symbol corresponding to each subcarrier is subtracted from Remove the phase angle at the first time slot reference symbol on the corresponding subcarrier to obtain the frequency offset between the two reference symbols on each subcarrier, and divide the frequency offset between the two reference symbols on each subcarrier by (6+ 1), respectively obtain the frequency offset between the adjacent OFDM symbols of each subcarrier, in the embodiment of the present invention, if there is no frequency offset at the reference symbol (the 4th symbol) of the first time slot of each subcarrier, then in The frequency offset at the 5th symbol is the frequency offset between the above-mentioned adjacent OFDM symbols, and the frequency offset at the 6th symbol is based on the frequency offset of the 5th symbol plus the frequency offset between adjacent OFDM symbols, in turn By analogy, until the last symbol of the second slot, and for the frequency offset at the adjacent OFDM symbol where the frequency offset at the third symbol is negative, the frequency offset at the second symbol is the third symbol Based on the frequency offset at the negative adjacent OFDM symbols, and so on, the frequency offset of the service data symbols contained in each subcarrier can be calculated.

Step 305: Adjust the frequency of the service data symbols according to the estimated frequency offset of the service data symbols corresponding to each subcarrier.

Based on the above technical solution, in the embodiment of the present invention, by obtaining the accurate channel estimation value of each subcarrier, the power value of the corresponding subcarrier is calculated respectively, and the target resource block is selected according to the power value corresponding to each subcarrier, and according to the target resource block The accurate channel estimation value of each subcarrier in the subcarrier, and the reference symbol preset for each subcarrier, calculate the frequency offset estimation value of the service data symbol contained in each subcarrier, according to the frequency offset estimation of the service data symbol corresponding to each subcarrier value, to adjust the frequency of the service data symbols. For the method of frequency offset estimation using the frequency domain autocorrelation algorithm, the method provided by the embodiment of the present invention can realize the frequency offset estimation without using the frequency domain autocorrelation algorithm, and overcomes the autocorrelation interval in the frequency domain autocorrelation algorithm. It is difficult to select, and there is no need to switch back and forth between coarse estimation and fine estimation, which improves the efficiency and accuracy of frequency offset estimation; for the method of frequency offset estimation using time-domain autocorrelation algorithm, it overcomes the unforeseen Strictly keeping time accurate synchronization will bring the disadvantage of large frequency offset error; in addition, the present invention only needs to obtain the time domain zero point in the calculation process of frequency domain conversion time domain in resource blocks, so the arithmetic mean is used to replace the complex calculation And the FFT operation consumes a lot of circuit resources; at the same time, there is no need to construct a training matrix or filter the channel impulse response, which is convenient for hardware implementation.

In summary, the frequency offset estimation method provided by the embodiment of the present invention can improve the efficiency and accuracy of frequency offset estimation, reduce the resources consumed by the system, and reduce the complexity of hardware implementation.

Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention also intends to include these modifications and variations.

Claims (10)

1. a frequency deviation estimating method, is characterized in that, comprising:

The transmission signal of mobile terminal receive, calculate the accurate channel estimation value that each subcarrier of the described transmission signal of carrying is corresponding respectively, be specially, the transmission signal of mobile terminal receive, according to the rough channel estimation value of each subcarrier of described transmission signal acquisition, the rough channel estimation value of each subcarrier to be multiplied with the rough channel estimation value of N number of subcarrier of being separated by and after adding up, to be partially worth when calculating phase angle and obtain described mobile terminal overall; Adopt obtain overall time be partially worth, calculate each subcarrier time inclined, and according to described each subcarrier time inclined, accordingly partial compensation for the time is carried out to the rough channel estimation value of each subcarrier, accurate channel estimation value inclined when being eliminated;

Based on each accurate channel estimation value obtained, calculate the performance number of corresponding subcarrier respectively;

The Resource Block of the division in certainty annuity, wherein, comprises the subcarrier specified number in each Resource Block, and the performance number corresponding according to each subcarrier, choose target resource block;

Respectively according to the accurate channel estimation value of each subcarrier in described target resource block, and for the reference symbol that each subcarrier is preset, calculate the frequency deviation estimated value of the business datum symbol that each subcarrier comprises;

According to the frequency deviation estimated value of business datum symbol corresponding to each subcarrier, frequency adjustment is carried out to business datum symbol.

2. the method for claim 1, is characterized in that, the performance number corresponding according to each subcarrier, chooses target resource block, comprising:

The performance number corresponding according to each subcarrier, selects the minimum sub-carrier power value in each Resource Block respectively;

The minimum sub-carrier power value chosen from each Resource Block is compared, and therefrom chooses maximum sub-carrier power value, using Resource Block corresponding for described maximum sub-carrier power value as target resource block.

3. method as claimed in claim 2, is characterized in that, using Resource Block corresponding for described maximum sub-carrier power value as target resource block, comprising:

Determine the subframe that subcarrier corresponding to described maximum sub-carrier power value comprises;

Using the target resource block of Resource Block corresponding for described subframe first slot reference symbol place as described subframe.

4. the method for claim 1, it is characterized in that, respectively according to the accurate channel estimation value of each subcarrier in described target resource block, and for the reference symbol that each subcarrier is preset, calculate the frequency deviation estimated value of the business datum symbol that each subcarrier comprises, comprising:

According to the accurate channel estimation value of subcarrier each in target resource block, and for the reference symbol that each subcarrier is preset, calculate the value at corresponding with each subcarrier accurate channel estimation value time domain zero point respectively, and calculate the frequency deviation estimated value at reference symbol place corresponding to described target resource block based on the value at described time domain zero point;

Respectively the frequency deviation estimated value at two reference symbol places that each subcarrier in described target resource block obtains continuously is done difference, obtain the frequency deviation estimated value between two reference symbols on described each subcarrier respectively, and calculate the frequency deviation estimated value of the business datum symbol that corresponding subcarrier comprises based on the frequency deviation estimated value between the reference symbol of two on each subcarrier respectively.

5. method as claimed in claim 4, is characterized in that, when calculating the value at corresponding with each subcarrier accurate channel estimation value time domain zero point respectively, comprising:

Respectively each subcarrier accurate channel estimation value is transformed to time domain by inverse Fourier transform, and by frequency domain front 2 the mean value of the index doubly accurate channel estimation value of a subcarrier be approximately the value at described time domain zero point.

6. a frequency deviation estimation device, is characterized in that, comprising:

Precise channel estimation module, for the transmission signal of mobile terminal receive, calculate the accurate channel estimation value that each subcarrier of the described transmission signal of carrying is corresponding respectively, be specially: the transmission signal of mobile terminal receive, according to the rough channel estimation value of each subcarrier of described transmission signal acquisition, the rough channel estimation value of each subcarrier to be multiplied with the rough channel estimation value of N number of subcarrier of being separated by and after adding up, to be partially worth when calculating phase angle and obtain described mobile terminal overall; Adopt obtain overall time be partially worth, calculate each subcarrier time inclined, and according to described each subcarrier time inclined, accordingly partial compensation for the time is carried out to the rough channel estimation value of each subcarrier, accurate channel estimation value inclined when being eliminated;

Power computation module, for based on each accurate channel estimation value obtained, calculates the performance number of corresponding subcarrier respectively;

Resource Block selects module, for the Resource Block of the division in certainty annuity, wherein, comprises the subcarrier specified number in each Resource Block, and the performance number corresponding according to each subcarrier, choose target resource block;

Frequency deviation estimating modules, for respectively according to the accurate channel estimation value of each subcarrier in described target resource block, and for the reference symbol that each subcarrier is preset, calculates the frequency deviation estimated value of the business datum symbol that each subcarrier comprises;

Adjusting module, for the frequency deviation estimated value according to business datum symbol corresponding to each subcarrier, carries out frequency adjustment to business datum symbol.

7. device as claimed in claim 6, is characterized in that, the performance number that described Resource Block selects module corresponding according to each subcarrier, chooses target resource block, is specially:

The performance number corresponding according to each subcarrier, selects the minimum sub-carrier power value in each Resource Block respectively;

The minimum sub-carrier power value chosen from each Resource Block is compared, and therefrom chooses maximum sub-carrier power value, using Resource Block corresponding for described maximum sub-carrier power value as target resource block.

8. device as claimed in claim 7, it is characterized in that, described Resource Block select module using Resource Block corresponding for described maximum sub-carrier power value as target resource block time, determine the subframe that subcarrier corresponding to described maximum sub-carrier power value comprises, using the target resource block of Resource Block corresponding for described subframe first slot reference symbol place as described subframe.

9. device as claimed in claim 6, it is characterized in that, described frequency deviation estimating modules is respectively according to the accurate channel estimation value of each subcarrier in described target resource block, and for the reference symbol that each subcarrier is preset, calculate the frequency deviation estimated value of the business datum symbol that each subcarrier comprises, be specially:

According to the accurate channel estimation value of subcarrier each in target resource block, and for the reference symbol that each subcarrier is preset, calculate the value at corresponding with each subcarrier accurate channel estimation value time domain zero point respectively, and calculate the frequency deviation estimated value at reference symbol place corresponding to described target resource block based on the value at described time domain zero point;

Respectively the frequency deviation estimated value at two reference symbol places that each subcarrier in described target resource block obtains continuously is done difference, obtain the frequency deviation estimated value between two reference symbols on described each subcarrier respectively, and calculate the frequency deviation estimated value of the business datum symbol that corresponding subcarrier comprises based on the frequency deviation estimated value between the reference symbol of two on each subcarrier respectively.

10. device as claimed in claim 9, it is characterized in that, when described frequency deviation estimating modules calculates the value at corresponding with each subcarrier accurate channel estimation value time domain zero point respectively, respectively each subcarrier accurate channel estimation value is transformed to time domain by inverse Fourier transform, and by frequency domain front 2 the mean value of the index doubly accurate channel estimation value of a subcarrier be approximately the value at described time domain zero point.