CN106059979A - Carrier synchronization method in UFMC system - Google Patents

Abstract

The invention relates to a carrier synchronization method in a UFMC system, comprising the following steps: first, generating two sets of orthogonal codes at a sender, inserting the orthogonal codes as pilot sequences into original data, and modulating, filtering and sending the original data through UFMC; then, performing time-domain zero filling and 2N-FFT transform at a receiver, extracting data on even bands, sending the data to a filter matching the sender, getting the estimated value of data information using a zero forcing equalizer, extracting pilot signals and calculating the correlation between the two sets of pilot signals, and minimizing the correlation to achieve UFMC system carrier frequency synchronization; and finally, using an iterative algorithm to improve the accuracy of frequency offset estimation. According to the invention, the carrier frequency offset of the system is estimated by inserting a pilot frequency into each sub band of UFMC, so good properties of the UFMC system are maintained, and the accuracy and stability of frequency offset estimation are improved through iteration. Therefore, the bit error performance of the system is enhanced, the quality of communication is improved, and the design complexity of the filter in the UFMC system is reduced to a certain extent.

Description

A kind of carrier synchronization method in UFMC system

Technical field

The invention belongs to wireless communication technology field, relate to the carrier synchronization method in a kind of UFMC system.

Background technology

As the Typical Representative of multi-transceiver technology, OFDM technology is widely applied in 4G, but, below OFDM Shortcoming makes it be difficult to meet the demand under new scene.First, must synchronize between each subcarrier to keep orthogonality, " without live width Band " cost that synchronizes when there is magnanimity sensing node in community of special topic will be difficult to bear；Secondly, it uses square wave as base band Waveform, carrier wave secondary lobe is bigger；Finally, its CP length used is only relevant with wireless channel, and when frequent transmission short frame, CP can make Become a large amount of wastes of Radio Resource.Therefore OFDM (OFDM) may be no longer optimum selection under 5G scene, and having must Explore and develop a new generation's multi-transceiver technology.

UFMC (Universal filtered multicarrier, general filtering multicarrier) be combined with OFDM and The novel multi-transceiver technology of one that some advantages of FBMC propose, is the multi-transceiver technology paid close attention to of 5GNOW project team of European Union One of alternative.UFMC divides the spectrum into a series of subband comprising several subcarriers, then carries out each subband Filtering operation.There is following characteristics: a) support fragmented spectrum communication；B) compared with OFDM, there is relatively low band external leakage；C) for The interference of time and frequency-offset and intercarrier has higher robustness；D) owing to using the strictest time-frequency calibration, reduce signaling and open Pin, this also introduces the newest selection for accessing；E) it is critical only that the design of wave filter, there is certain complexity.

In view of the advantage of UFMC technology, combine again existing pilot aided OFDMA (centralized subchannel) Frequency Synchronization Thought: deposit frequency pilot sign in the centre of each Resource Block, carries out CFO estimation by this frequency pilot sign at frequency domain receiving terminal, this Invention proposes a kind of carrier frequency synchronization method in UFMC system, by each subband of UFMC as a money in OFDMA Source block, is carried out pilot signal insertion to it, thus is carried out the estimation of CFO by pilot signal.

Summary of the invention

In view of this, it is an object of the invention to provide the carrier synchronization method in a kind of UFMC system, the method is not only The advantage that can retain UFMC system itself, and communication quality can be improved, reduce to a certain extent in UFMC and filter The design complexities of device.

For reaching above-mentioned purpose, the present invention provides following technical scheme:

Carrier synchronization method in a kind of UFMC system, in UFMC system, inserts pilot signal to each subband, passes through Pilot signal realizes the carrier frequency synchronization of system, specifically includes following steps:

S1: generate the hadamard matrix M of a nB × nB_P, choose matrix M_PAny two rows or two columns P_n,P_m, and will It inserts in UFMC signal as pilot frequency sequence, and meets nBmod (4)=0, P_n×P_m ^*=0；

S2: N number of subcarrier is divided evenly into B group (i.e. B subband), then contain in each subbandHeight carries Ripple；Assume in each subband, select n sub-carrier-wave transmission pilot signal, remaining D-n sub-carrier-wave transmission data signal, insert After pilot tone, the signal in subband i is S_i, it is X that frequency domain sends signal；

S3: after obtaining the UFMC signal X including pilot signal, allow B the subband of UFMC sequentially pass through N-IDFT and Filter two processes to be modulated sending；

S4: the receiving terminal signal to receiving carries out serial to parallel conversion and time domain zero padding, obtains parallel signal；

S5: the parallel signal obtained carries out following operation: first carry out 2N-FFT conversion, obtains the frequency domain letter of 2N point Number, take the data message of its even frequency and by it by the wave filter matched with transmitting terminal, finally utilize zero forcing equalizer to disappear Except ISI, obtain the estimated value of data message；

S6: extract pilot signal, then estimate carrier wave frequency deviation by calculating the dependency between two groups of pilot frequency sequences CFO；

S7: degree of accuracy and the stability that frequency deviation is estimated by utilizing iterative algorithm to improve.

Further, D subcarrier select n subcarrier deposit pilot tone, the position Ψ of pilot tone in subband i_iRepresent, as Fruit deposits pilot tone on the r subcarrier in subband i, then [Ψ_i]_r,r=1, otherwise [Ψ_i]_r,r=0, wherein r ∈ [1, D],In UFMC signal, the position of all pilot tones is Ψ=diag [Ψ₁,…,Ψ_B],In subband i Pilot signal and initial data constitute new data message S_i, frequency domain sends signal and is

Further, the data message S to each subband_iRealize IDFT by Fourier's matrix to convert, this Fourier's matrix It is defined asRepresent a length of d₂Vector carry out d₁The IDFT conversion of point；Element in the middle of Fourier's matrix As follows:

$V_{n,m}=\frac{1}{\sqrt{d_1}}{e}^{\frac{j2\mathrm{\π}nm}{d_1}},0\≤m\≤d_2-1,0\≤n\≤d_1-1---\left(1\right)$

Wherein n, m are element subscript.

Further, each subband is filtered operation, transports by using toeplitz matrix to complete this linear convolution Calculate, different subbands is needed to move to the mid frequency of wave filter the centre of subband；The filter of UFMC system mesarcs is set The a length of L of ripple device, the expression formula of impulse response f is: f={f [0], f [1] ..., f [L-1] }, corresponding frequency domain response is F；Meter The subcarrier index calculating i-th sub-band mid frequency place is:By the frequency domain response F of ptototype filter TranslationIndividual unit obtains the frequency domain response F of i-th sub-band_i, rushing of the i-th sub-band of symbol m Hit response f_m,iFor: f_m,i={ f_m,i[0],f_m,i[1],…,f_m,i[L-1] }, wherein0≤n≤L-1； Definition toeplitz matrix F_m,iFor:

Take its front N row to be designated asWithRealize the filtering of the i-th subband of symbol m.

Further, after UFMC modulation, filtering, two continuous print time-domain signal x that transmitting terminal sends₁,x₂It is respectively as follows:

$\begin{array}{c}{x}_1=\underset{i=1}{\overset{B}{\Σ}}{F}_{1,i}^N{V}_i{S}_{1,i}\\ x_2=\underset{i=1}{\overset{B}{\Σ}}{F}_{2,i}^N{V}_i{S}_{2,i}\end{array}---\left(3\right)$

Wherein, V_iRepresent the Fourier's matrix realizing IDFT conversion on i-th sub-bandAnd d₁And d₂Value Factor band and different.

Further, two continuous print time-domain signal y that receiving terminal receives₁,y₂It is respectively as follows:

$\begin{array}{c}{y}_1=\mathrm{\Γ}\left(\mathrm{\ϵ}\right)x_1+w_1\\ =\mathrm{\Γ}\left(\mathrm{\ϵ}\right)\underset{i=1}{\overset{B}{\Σ}}{F}_{1,i}^N{V}_i{S}_{1,i}+w_1\\ y_2=\mathrm{\Λ}\left(\mathrm{\ϵ}\right)\mathrm{\Γ}\left(\mathrm{\ϵ}\right)x_2+w_2\\ =\mathrm{\Λ}\left(\mathrm{\ϵ}\right)\mathrm{\Γ}\left(\mathrm{\ϵ}\right)\underset{i=1}{\overset{B}{\Σ}}{F}_{2,i}^N{V}_i{S}_{2,i}+w_2\end{array}---\left(4\right)$

Wherein: Λ (ε)=e^{j2πε(N+L-1)/N}I_NRepresent the phase place change caused by carrier deviation, this change and carrier frequency rate Deviation is relevant with symbol sequence number；Γ (ε)=diag{1, e^j2πε/N,…,e^{j2πε(N+L-1)/N}Represent that the impact of carrier wave frequency deviation CFO rings Should, ε represents normalized carrier frequency offset.

Further, do 2N-FFT conversion after the signal received is carried out time domain zero padding and obtain the frequency-region signal of 2N point, take Its even frequency obtains estimating signalPilot signal T is therefrom extracted after being filtered coupling₁、T₂。

Further, if removing and receiving pilot signal T₁、T₂In the interference that brought by CFO and phase place rotate, then pilot tone Signal T₁、T₂Dependency will become the least, its dependency formula can be expressed as:

$R_{1,2}={\left(\mathrm{\Π}\right(\widetilde{\mathrm{\ϵ}}\left)T_1\right)}^{*}\·\left(\mathrm{\Λ}\right(\widetilde{\mathrm{\ϵ}})\Π\left(\widehat{\mathrm{\ϵ}}\right)T_2)---\left(5\right)$

In formula:Represent the frequency response of CFO,Represent the test of normalized carrier frequency offset Value；ByValue be [-0.5,0.5) in the range of, make cost function R_1,2Minimize the estimated value obtaining CFO, i.e.

$\widehat{\mathrm{\ϵ}}=\underset{\widetilde{\mathrm{\ϵ}}\∈\[-0.5,0.5)}{\mathrm{argmin}}{R}_{1,2}---\left(6\right).$

Further, in the step s 7, iterative algorithm is used to improve arithmetic accuracy: to assume in each iterative process, will Regard that residue CFO estimates as, then, in the g time iteration, accurate CFO estimated valueIt is formulated as:

${\widehat{\mathrm{\ϵ}}}^{g+1}={\widehat{\mathrm{\ϵ}}}^g+\widehat{\mathrm{\ϵ}}---\left(7\right)$

It is used for compensating the pilot signal that receiving terminal receives, revised pilot signal by accurate CFOFor:

$\begin{array}{c}{{\hat{T}}_1}^{g+1}=\mathrm{\Λ}\left({\widehat{\mathrm{\ϵ}}}^{g+1}\right)\Π\left({\widehat{\mathrm{\ϵ}}}^{g+1}\right)T_1\\ {{\hat{T}}_2}^{g+1}=\mathrm{\Λ}\left({\widehat{\mathrm{\ϵ}}}^{g+1}\right)\Π\left({\widehat{\mathrm{\ϵ}}}^{g+1}\right)T_2\end{array}---\left(8\right).$

The beneficial effects of the present invention is: the present invention carrys out the load of estimating system by inserting pilot signal in UFMC system Wave frequency deviation, not only can retain the superperformance of UFMC system, and can improve the degree of accuracy of frequency deviation estimation and stablize Property, reduce the interference between the sub-band and subcarrier brought due to CFO to a great extent, thus improve the mistake ratio of system Characteristic energy, improves the reliability of transmission.

Accompanying drawing explanation

In order to make the purpose of the present invention, technical scheme and beneficial effect clearer, the present invention provides drawings described below to carry out Illustrate:

Fig. 1 is the schematic diagram of pilot tone interleaved plan in OFDMA；

Fig. 2 be the present invention UFMC system in the schematic diagram of pilot tone interleaved plan；

Fig. 3 be the present invention UFMC system in pilot aided carrier frequency synchronization method structured flowchart；

Fig. 4 is that the CFO of the present invention estimates and the Diagram of the Supreme Ultimate of compensation；

Fig. 5 is the schematic flow sheet of the present invention.

Detailed description of the invention

Below in conjunction with accompanying drawing, the preferred embodiments of the present invention are described in detail.

Fig. 5 is the schematic flow sheet of the carrier synchronization method in UFMC system of the present invention, as it can be seen, this method Comprise the following steps:

S1: generate the hadamard matrix M of a nB × nB_P, choose matrix M_PAny two rows or two columns P_n,P_m, and will It inserts in UFMC signal as pilot frequency sequence, and meets nBmod (4)=0, P_n×P_m ^*=0；

S2: N number of subcarrier is divided evenly into B group (i.e. B subband), then contain in each subbandHeight carries Ripple；Assume in each subband, select n sub-carrier-wave transmission pilot signal, remaining D-n sub-carrier-wave transmission data signal, insert After pilot tone, the signal in subband i is S_i, it is X that frequency domain sends signal；

S3: after obtaining the UFMC signal X including pilot signal, allow B the subband of UFMC sequentially pass through N-IDFT and Filter two processes to be modulated sending；

S4: the receiving terminal signal to receiving carries out serial to parallel conversion and time domain zero padding, obtains parallel signal；

S5: the parallel signal obtained carries out following operation: first carry out 2N-FFT conversion, obtains the frequency domain letter of 2N point Number, take the data message of its even frequency and by it by the wave filter matched with transmitting terminal, finally utilize zero forcing equalizer to disappear Except ISI, obtain the estimated value of data message；

S6: extract pilot signal, then estimate carrier wave frequency deviation by calculating the dependency between two groups of pilot frequency sequences CFO；

S7: degree of accuracy and the stability that frequency deviation is estimated by utilizing iterative algorithm to improve.

In the present embodiment, as shown in Figure 1, Fig. 2 is the UFMC system of the present invention to the introducing background of pilot interposition method The schematic diagram of middle pilot tone interleaved plan, specifically, the method comprises the following steps:

1, in UFMC system, it is 1024 points that IDFT counts, and has 10 subbands, comprises 12 subcarriers in each subband. Generate the hadamard matrix M of 40 × 40_P, choose matrix M_PFront two row P₁,P₂As pilot frequency sequence.

2, the inserted mode of pilot tone is: select 4 subcarriers to deposit pilot tone on 12 subcarriers, deposits at carrier wave for remaining 8 Put data.Pilot signal and initial data in subband i constitute new data message S_i, frequency domain sends signal and is The position Ψ of pilot tone in subband i_iRepresent, if depositing pilot tone on the r subcarrier in subband i, then [Ψ_i]_r,r= 1, otherwise [Ψ_i]_r,r=0, wherein r ∈ [1,12],In UFMC signal, the position of all pilot tones is Ψ=diag [Ψ₁,…,Ψ_B],

Fig. 3 be the present invention UFMC system in pilot aided carrier frequency synchronization method structured flowchart, as it can be seen, should Method specifically includes following steps:

1, the data message S to each subband_iRealizing IDFT by Fourier's matrix to convert, this Fourier's matrix is defined as V_12×1024={ V_n,m, the element in the middle of Fourier's matrix is as follows:

$V_{n,m,i}=\frac{1}{\sqrt{1024}}{e}^{\frac{j2\mathrm{\π}nm}{1024}},12(i-1)+1\≤m\≤12i,0\≤n\≤1023$

2, each subband is filtered operation, by using toeplitz matrix to complete this linear convolution operation, right Need to move to the mid frequency of wave filter the centre of subband in different subbands.It is long that UFMC system mesarcs wave filter is set Degree is L=74, and the expression formula of impulse response f is: f={f [0], f [1] ..., f [L-1] }, corresponding frequency domain response is F；Calculate The subcarrier index at i-th sub-band mid frequency place is: 6.5+ (i-1) 12, is translated by the frequency domain response F of ptototype filter k_i=6.5+12 (i-1) individual unit obtains the frequency domain response F of i-th sub-band_i, the shock response of the i-th sub-band of symbol m f_m,iFor: f_m,i={ f_m,i[0],f_m,i[1],…,f_m,i[L-1] }, wherein0≤n≤L-1；Definition torr Puli's hereby matrix F_m,iFor:

Take its front N row to be designated asWithRealize the filtering of the i-th subband of symbol m.

3, after UFMC modulation, filtering, two continuous print time-domain signal x that transmitting terminal sends₁,x₂It is respectively as follows:

$x_1=\underset{i=1}{\overset{B}{\Σ}}{F}_{1,i}^N{V}_i{S}_{1,i}$

$x_2=\underset{i=1}{\overset{B}{\Σ}}{F}_{2,i}^N{V}_i{S}_{2,i}$

4, two continuous print time-domain signal y that receiving terminal receives₁,y₂It is respectively as follows:

$\begin{array}{c}{y}_1=\mathrm{\Γ}\left(\mathrm{\ϵ}\right)x_1+w_1\\ =\mathrm{\Γ}\left(\mathrm{\ϵ}\right)\underset{i=1}{\overset{B}{\Σ}}{F}_{1,i}^N{V}_i{S}_{1,i}+w_1\end{array}$

$\begin{array}{c}{y}_2=\mathrm{\Λ}\left(\mathrm{\ϵ}\right)\mathrm{\Γ}\left(\mathrm{\ϵ}\right)x_2+w_2\\ =\mathrm{\Λ}\left(\mathrm{\ϵ}\right)\mathrm{\Γ}\left(\mathrm{\ϵ}\right)\underset{i=1}{\overset{B}{\Σ}}{F}_{2,i}^N{V}_i{S}_{2,i}+w_2\end{array}$

Wherein: Λ (ε)=e^{j2πε(N+L-1)/N}I_NRepresent the phase place change caused by carrier deviation, this change and carrier frequency rate Deviation is relevant with symbol sequence number；Γ (ε)=diag{1, e^j2πε/N,...,e^{j2πε(N+L-1)/N}Represent that the impact of carrier wave frequency deviation CFO rings Should, ε represents normalized carrier frequency offset.

5, do 2N-FFT conversion after the signal received being carried out time domain zero padding and obtain the frequency-region signal of 2N point, take its even frequency Point obtains estimating signalPilot signal T is therefrom extracted after being filtered coupling₁、T₂。

1) time domain zero padding:

r₁=[0_[1×(N-L+1)],y_{1[1×(N+L-1)]}]^T

r₂=[0_[1×(N-L+1)],y_{2[1×(N+L-1)]}]^T

2) 2N-FFT conversion:

$Y_1=V_{2N\×2N}^H{r}_1$

$Y_2=V_{2N\×2N}^H{r}_2$

3) take even frequency and carry out matched filtering:

$Z_1={\left(\underset{i=1}{\overset{B}{\Σ}}{F}_{1,i}^N\right)}^{-1}{\hat{Y}}_1$

$Z_2={\left(\underset{i=1}{\overset{B}{\Σ}}{F}_{2_i}^N\right)}^{-1}{\hat{Y}}_2$

4) pilot signal extracted: T₁=Ψ Z₁,T₂=Ψ Z₂

If 6 remove in reception pilot signal T₁、T₂In the interference that brought by CFO and phase place rotate, then pilot signal T₁、T₂Dependency will become the least, its dependency formula can be expressed as:

$R_{1,2}={\left(\mathrm{\Π}\right(\widetilde{\mathrm{\ϵ}}\left)T_1\right)}^{*}\·\left(\mathrm{\Λ}\right(\widetilde{\mathrm{\ϵ}})\Π\left(\widehat{\mathrm{\ϵ}}\right)T_2)$

In formula:Represent the frequency response of CFO,Represent the test of normalized carrier frequency offset Value；ByValue be [-0.5,0.5) in the range of, make cost function R_1,2Minimize the estimated value obtaining CFO, i.e.

$\widehat{\mathrm{\ϵ}}=\underset{\widetilde{\mathrm{\ϵ}}\∈\[-0.5,0.5)}{\mathrm{argmin}}{R}_{1,2}$

Fig. 4 is the Diagram of the Supreme Ultimate that the CFO of the present invention estimates and compensates, as it can be seen, the method specifically includes following steps:

1, assume in each iterative process, willRegard that residue CFO estimates as, in the g time iteration, accurate CFO Estimated valueIt is formulated as:

${\widehat{\mathrm{\ϵ}}}^{g+1}={\widehat{\mathrm{\ϵ}}}^g+\widehat{\mathrm{\ϵ}}$

It is used for compensating the pilot signal that receiving terminal receives, revised pilot signal by accurate CFOFor:

${{\hat{T}}_1}^{g+1}=\mathrm{\Λ}\left({\widehat{\mathrm{\ϵ}}}^{g+1}\right)\Π\left({\widehat{\mathrm{\ϵ}}}^{g+1}\right)T_1$ ${{\hat{T}}_2}^{g+1}=\mathrm{\Λ}\left({\widehat{\mathrm{\ϵ}}}^{g+1}\right)\Π\left({\widehat{\mathrm{\ϵ}}}^{g+1}\right)T_2$

2, in UFMC system, the iterative algorithm of carrier frequency synchronization can be summarized as following several step:

1): initialize；Allow g=0,

2): iteration；G represents total iterations, and g=1,2 ..., G.

Finally illustrate, preferred embodiment above only in order to technical scheme to be described and unrestricted, although logical Cross above preferred embodiment the present invention to be described in detail, it is to be understood by those skilled in the art that can be In form and it is made various change, without departing from claims of the present invention limited range in details.

Claims (9)

1. the carrier synchronization method in a UFMC system, it is characterised in that: in UFMC system, each subband is inserted pilot tone Signal, realizes the carrier frequency synchronization of system by pilot signal, specifically includes following steps:

S1: generate the hadamard matrix M of a nB × nB_P, choose matrix M_PAny two rows or two columns P_n,P_m, and made Insert in UFMC signal for pilot frequency sequence, and meet nBmod (4)=0, P_n×P_m ^*=0；

S2: N number of subcarrier is divided evenly into B group (i.e. B subband), then contain in each subbandIndividual subcarrier；False It is located in each subband n sub-carrier-wave transmission pilot signal of selection, remaining D-n sub-carrier-wave transmission data signal, inserts pilot tone After, the signal in subband i is S_i, it is X that frequency domain sends signal；

S3: after obtaining the UFMC signal X including pilot signal, allows B the subband of UFMC sequentially pass through N-IDFT and filtering Two processes are modulated sending；

S4: the receiving terminal signal to receiving carries out serial to parallel conversion and time domain zero padding, obtains parallel signal；

S5: the parallel signal obtained is carried out following operation: first carry out 2N-FFT conversion, obtain the frequency-region signal of 2N point, take The data message of its even frequency and by it by the wave filter matched with transmitting terminal, finally utilize zero forcing equalizer to eliminate ISI, Obtain the estimated value of data message；

S6: extract pilot signal, then estimate carrier wave frequency deviation CFO by calculating the dependency between two groups of pilot frequency sequences；

S7: degree of accuracy and the stability that frequency deviation is estimated by utilizing iterative algorithm to improve.

Carrier synchronization method in a kind of UFMC system the most according to claim 1, it is characterised in that: at D subcarrier On select n subcarrier to deposit pilot tone, the position Ψ of pilot tone in subband i_iRepresent, if on the r subcarrier in subband i Deposit pilot tone, then [Ψ_i]_r,r=1, otherwise [Ψ_i]_r,r=0, wherein r ∈ [1, D],UFMC signal owns The position of pilot tone isPilot signal and initial data in subband i constitute new number It is believed that breath S_i, frequency domain sends signal and is

Carrier synchronization method in a kind of UFMC system the most according to claim 2, it is characterised in that: to each subband Data message S_iRealizing IDFT by Fourier's matrix to convert, this Fourier's matrix is defined asRepresent length For d₂Vector carry out d₁The IDFT conversion of point；Element in the middle of Fourier's matrix is as follows:

$V_{n,m}=\frac{1}{\sqrt{d_1}}{e}^{\frac{j2\mathrm{\π}nm}{d_1}},0\≤m\≤d_2-1,0\≤n\≤d_1-1---\left(1\right)$

Wherein n, m are element subscript.

Carrier synchronization method in a kind of UFMC system the most according to claim 3, it is characterised in that: each subband is entered Row filtering operation, by using toeplitz matrix to complete this linear convolution operation, needing for different subbands will filtering The mid frequency of device moves to the centre of subband；Arranging UFMC system mesarcs filter length is L, the expression of impulse response f Formula is: f={f [0], f [1] ..., f [L-1] }, corresponding frequency domain response is F；Calculate i-th sub-band mid frequency place Subcarrier index is:The frequency domain response F of ptototype filter is translatedIndividual unit obtains Frequency domain response F to i-th sub-band_i, the shock response f of the i-th sub-band of symbol m_m,iFor: f_m,i={ f_m,i[0],f_m,i [1],…,f_m,i[L-1] }, whereinDefinition toeplitz matrix F_m,iFor:

Take its front N row to be designated asWithRealize the filtering of the i-th subband of symbol m.

Carrier synchronization method in a kind of UFMC system the most according to claim 4, it is characterised in that: adjust through UFMC After system, filtering, two continuous print time-domain signal x that transmitting terminal sends₁,x₂It is respectively as follows:

$\begin{array}{c}{x}_1=\underset{i=1}{\overset{B}{\Σ}}{F}_{1,i}^N{V}_i{S}_{1,i}\\ x_2=\underset{i=1}{\overset{B}{\Σ}}{F}_{2,i}^N{V}_i{S}_{2,i}\end{array}---\left(3\right)$

Wherein, V_iRepresent the Fourier's matrix realizing IDFT conversion on i-th sub-bandAnd d₁And d₂The value factor Band and different.

Carrier synchronization method in a kind of UFMC system the most according to claim 5, it is characterised in that: receiving terminal receives Two continuous print time-domain signal y₁,y₂It is respectively as follows:

$\begin{array}{c}{y}_1=\mathrm{\Γ}\left(\mathrm{\ϵ}\right)x_1+w_1\\ =\mathrm{\Γ}\left(\mathrm{\ϵ}\right)\underset{i=1}{\overset{B}{\mathrm{\Σ}}}{F}_{1,i}^N{V}_i{S}_{1,i}+w_1\\ y_2=\mathrm{\Λ}\left(\mathrm{\ϵ}\right)\mathrm{\Γ}\left(\mathrm{\ϵ}\right)x_2+w_2\\ =\mathrm{\Λ}\left(\mathrm{\ϵ}\right)\mathrm{\Γ}\left(\mathrm{\ϵ}\right)\underset{i=1}{\overset{B}{\mathrm{\Σ}}}{F}_{2,i}^N{V}_i{S}_{2,i}+w_2\end{array}---\left(4\right)$

Wherein: Λ (ε)=e^{j2πε(N+L-1)/N}I_NRepresent the phase place change caused by carrier deviation, this change and load frequency departure Relevant with symbol sequence number；Γ (ε)=diag{1, e^j2πε/N,…,e^{j2πε(N+L-1)/N}Represent carrier wave frequency deviation CFO shock response, ε Represent normalized carrier frequency offset.

Carrier synchronization method in a kind of UFMC system the most according to claim 6, it is characterised in that: the letter that will receive Do 2N-FFT conversion after number carrying out time domain zero padding and obtain the frequency-region signal of 2N point, take its even frequency and obtain estimation signalEnter Pilot signal T is therefrom extracted after row filtering coupling₁、T₂。

Carrier synchronization method in a kind of UFMC system the most according to claim 7, it is characterised in that: connecing if removed Receive pilot signal T₁、T₂In the interference that brought by CFO and phase place rotate, then pilot signal T₁、T₂Dependency will become very Little, its dependency formula can be expressed as:

$R_{1,2}={\left(\mathrm{\Π}\right(\widetilde{\mathrm{\ϵ}}\left)T_1\right)}^{*}\·\left(\mathrm{\Λ}\right(\widetilde{\mathrm{\ϵ}}\left)\mathrm{\Π}\right(\widetilde{\mathrm{\ϵ}}\left)T_2\right)---\left(5\right)$

In formula:Represent the frequency response of CFO,Represent the test value of normalized carrier frequency offset； ByValue be [-0.5,0.5) in the range of, make cost function R_1,2Minimize the estimated value obtaining CFO, i.e.

$\widehat{\mathrm{\ϵ}}=\underset{\widetilde{\mathrm{\ϵ}}\∈\[-0.5,0.5)}{\mathrm{argmin}}{R}_{1,2}---\left(6\right).$

Carrier synchronization method in a kind of UFMC system the most according to claim 8, it is characterised in that: in the step s 7, Iterative algorithm is used to improve arithmetic accuracy: to assume in each iterative process, willRegard that residue CFO estimates as, then, In the g time iteration, accurate CFO estimated valueIt is formulated as:

${\widehat{\mathrm{\ϵ}}}^{g+1}={\widehat{\mathrm{\ϵ}}}^g+\widehat{\mathrm{\ϵ}}---\left(7\right)$

It is used for compensating the pilot signal that receiving terminal receives, revised pilot signal by accurate CFOFor:

$\begin{array}{c}{{\hat{T}}_1}^{g+1}=\mathrm{\Λ}\left({\widehat{\mathrm{\ϵ}}}^{g+1}\right)\mathrm{\Π}\left({\widehat{\mathrm{\ϵ}}}^{g+1}\right)T_1\\ {{\hat{T}}_2}^{g+1}=\mathrm{\Λ}\left({\widehat{\mathrm{\ϵ}}}^{g+1}\right)\mathrm{\Π}\left({\widehat{\mathrm{\ϵ}}}^{g+1}\right)T_2\end{array}---\left(8\right).$