CN101330483A

CN101330483A - Synchronization method and apparatus for digital audio broadcast receiver

Info

Publication number: CN101330483A
Application number: CNA200710042127XA
Authority: CN
Inventors: 熊学泉; 王吉健; 陈正一; 赵小勇; 李新兵; 张平山
Original assignee: ANFAN MICROELECTRONICS(SHANGHAI) Co Ltd
Current assignee: ANFAN MICROELECTRONICS(SHANGHAI) Co Ltd
Priority date: 2007-06-18
Filing date: 2007-06-18
Publication date: 2008-12-24

Abstract

The invention relates to a synchronous method used for a digital audio broadcasting receiver. The method comprises the following steps: fractional frequency offset estimation, fractional frequency offset correction, integer frequency offset estimation and timing offset estimation are performed to data received at the acquisition phase, frequency offset correction is performed according to the fractional frequency offset estimation and the integer frequency offset estimation, and time offset correction is performed according to the timing offset estimation; the fractional frequency offset estimation and the timing offset estimation are performed to data received at the tracking phase, frequency offset correction is performed according to the fractional frequency offset estimation, time offset correction is performed according to the timing offset estimation, and the timing offset estimation is selfadaptive according to the signal-to-noise ratio. The method is applied to the digital audio broadcasting receiver of a mobile terminal, when the signal is weaker, the program is received at the mobile terminal for a long term, or the acceleration motion and the deceleration motion are performed at the mobile terminal suddenly at high speed, high quality audio broadcasting signals can be demodulated, and further the satisfying reception effect can be obtained.

Description

The method for synchronous and the device that are used for digital audio broadcast receiver

Technical field

The present invention relates to mobile communication technology, particularly relate to a kind of method for synchronous and device that is used for digital audio broadcast receiver.

Background technology

Mobile communication is most active in the communications field, tool a kind of communication mode of development prospect, is the wireless communication means of tool individualized feature in the current information-intensive society.Along with the development of mobile communication technology, be that the function of the mobile communication terminal of representative strengthens day by day with the mobile phone.In June, 2006, China formally implemented digital audio broadcasting (DAB, Digital Audio Broadcast) national standard (GY/T214.2006), and in Beijing, ground such as Shanghai, Guangdong digital audio broadcasting/DMB (DAB/T-DMB) program that started broadcasting, mobile phone can receive the Voice ﹠ Video program that meets Chinese DAB mobile TV standard.

But, domestic existing mobile phone can't accomplish to meet the signal to noise ratio (SNR of DAB national standard well at present, Signal Noise Rate) more than the 6db, the normal requirement that receives of translational speed 180km/h, just mobile phone image pause or mosaic phenomenon occur often at long-time program receiving or mobile phone high-speed mobile, especially reception is poorer under unexpected acceleration, deceleration situation, even the phenomenon that can occur crashing and can't use.The reason that causes above-mentioned phenomenon mainly is because the DAB receiver is done perfectly inadequately when receiving OFDM (OFDM, Orthogonal Frequency Division Multiplexing) signal synchronously in the mobile phone.

Ofdm system is to regularly and the frequency shift (FS) sensitivity, i.e. frequency shift (FS) meeting causes disturbing between the subcarrier of frequency domain, and timing slip can cause the phase place of time domain OFDM intersymbol interference and frequency domain to be rotated.Specifically, carrier frequency shift mainly is to produce because the oscillator frequency of transmitter and receiver is inconsistent, carrier frequency shift is divided into integer frequency offset (IFO, Integral Frequent Offset) and mark frequency multiplication (FFO partially, Fractional Frequent Offset), IFO makes the subcarrier in frequency domain that receives be offset the subcarrier spacing of integral multiple, at this moment subcarrier still keeps mutually orthogonal, but be positioned at wrong spectrum position after being mapped to the reception data symbol demodulation of OFDM frequency spectrum, this just causes the error rate to reach 0.5; FFO makes the subcarrier in frequency domain that receives be offset the subcarrier spacing of branch several times, the signal energy of such subcarrier is distributed to two adjacent subcarriers, therefore lose orthogonality between subcarrier, cause disturbing between subcarrier the increase of (ICI, Inter Carrier Interference) and the error rate.Different with frequency shift (FS), timing slip (TO, Timing Offset) can not cause ICI, but the fast fourier transform (FFT, Fast Fourier Transform) that can cause decomposing frequency-region signal is handled window and is comprised two continuous OFDM symbols, thereby has introduced OFDM intersymbol interference (ISI, Inter Symbol Interference), if and the skew of FFT processing window position, then the frequency spectrum of ofdm signal has been introduced the phase place rotation, the performance of ISI and the serious shadow ofdm system of phase place rotation meeting.

For these reasons, receive mainly the comprising synchronously regularly synchronously and carrier frequency synchronization of DAB receiver of ofdm signal.Timing frequency has frame synchronization and sign synchronization synchronously, and frame regularly is used for determining the starting position of a Frame synchronously, and timing synchronization is used for the correct starting position of making OFDM symbol data part.Carrier frequency synchronization is to detect frequency shift (FS) to be corrected again.The synchronizing process of DAB receiver is normally determined the starting point of frame at first roughly at present, and next uses the phase reference symbol (PRS, Phase Reference Symbol) after the FFT demodulation to carry out IFO or TO estimation and compensation, is that FFO estimates and compensation then.Because the starting point of frame is to estimate roughly, so ISI and phase deviation can occur in the restituted signal; And owing to be to carry out earlier that IFO or TO estimate and compensation, carry out that FFO estimates and compensation, the ICI that is caused by FFO can make based on the IFO of the PRS after the demodulation or TO estimates and the precision of compensation reduces, and influences the stability of system again.

Application number is that 200510080607.6 Chinese patent application discloses a kind of method for synchronous and equipment that is used for digital audio frequency/digital multimedia broadcasting receiver, it is every frame data transmission frame to be carried out FFO, IFO and TO estimate and compensation, all is to utilize identical FFO, IFO and TO to estimate and compensation method when receiving every frame data transmission frame just.Yet for portable terminal for example for the mobile phone, because it is not fixing the reception, the power of signal can change with moving of mobile phone, therefore when signal is more weak or mobile phone at a high speed, acceleration, deceleration campaign suddenly (in other words, signal changes fast) time, the accuracy that FFO, IFO and TO estimate can be seriously influenced, and then has also just influenced the reception of mobile phone.

Therefore, be necessary to provide a kind of method for synchronous and device that can improve the DAB receiver of portable terminal reception.

Summary of the invention

The problem that the present invention solves is, provide a kind of method for synchronous that is used for digital audio broadcast receiver and device that can improve the portable terminal reception, so that portable terminal is at long-time reception, high-speed mobile or normal program receiving under the acceleration, deceleration situation suddenly.

For addressing the above problem, the invention provides a kind of method for synchronous that is used for digital audio broadcast receiver, described method comprises acquisition phase and tracking phase, wherein, described acquisition phase comprises the steps:

(1) inclined to one side according to the inphase/quadrature phase data estimation mark frequency multiplication of the Cyclic Prefix of phase reference symbol;

(2) inclined to one side according to the mark frequency multiplication of step (1) gained, the inphase/quadrature phase data that receive are carried out mark frequency multiplication deflection correction, again to carrying out quick Fourier transformation computation through the inphase/quadrature phase data behind the mark frequency multiplication deflection correction;

(3) estimate integer frequency offset and timing slip according to the dateout of the quick Fourier transformation computation of signal to noise ratio and step (2) gained;

(4) digital controlled oscillator of the mark frequency multiplication of the integer frequency offset of step (3) gained and step (1) gained being sent into partially the Digital Down Convert of digital audio broadcast receiver goes to adjust the intermediate frequency value of digital controlled oscillator;

(5) when receiving the phase reference symbol of data transmission frames, the dateout of the fast fourier transform of the inphase/quadrature phase data that receive is done the time migration correction according to the timing slip of step (3) gained;

Described tracking phase comprises the steps:

(6) inclined to one side according to the inphase/quadrature phase data estimation mark frequency multiplication of the Cyclic Prefix of phase reference symbol and data symbol;

(7) estimate timing slip according to the dateout of the fast fourier transform of signal to noise ratio and inphase/quadrature phase data;

(8) digital controlled oscillator of the mark frequency multiplication of step (6) gained being sent into partially the Digital Down Convert of digital audio broadcast receiver goes to adjust the intermediate frequency value of digital controlled oscillator;

(9) when receiving the phase reference symbol of data transmission frames, the dateout of the fast fourier transform of the inphase/quadrature phase data that receive is done the time migration correction according to the timing slip of step (7) gained.

Wherein, described acquisition phase is meant when receiving the first frame data transmission frame; When described tracking phase is meant each data transmission frames after receiving the first frame data transmission frame.

Corresponding to above-mentioned method for synchronous, the present invention also provides a kind of synchronizer that is used for digital audio broadcast receiver, the course of work of described device comprises acquisition phase and tracking phase, described device comprises: the inclined to one side estimation module of mark frequency multiplication is used for according to the inphase/quadrature phase data estimation mark frequency multiplication of the Cyclic Prefix of phase reference symbol and data symbol inclined to one side; Mark frequency multiplication deflection correction module, be used for according to the mark frequency multiplication of the inclined to one side estimation module gained of mark frequency multiplication inclined to one side, the inphase/quadrature phase data that receive are carried out mark frequency multiplication deflection correction, will give the fast fourier transform of digital audio broadcast receiver/contrary fast fourier transform module through the inphase/quadrature phase data behind the mark frequency multiplication deflection correction again and carry out quick Fourier transformation computation; Integer frequency offset is estimated and the timing slip estimation module, is used for dateout estimation integer frequency offset and timing slip according to the fast fourier transform of signal to noise ratio and inphase/quadrature phase data; The frequency deviation adjusting module is used for according to the mark frequency multiplication of the inclined to one side estimation module gained of mark frequency multiplication partially and integer frequency offset is estimated and the intermediate frequency value of the digital controlled oscillator of the Digital Down Converter Module of the integer frequency offset adjustment digital audio broadcast receiver of timing slip estimation module gained; The time migration correcting module is used for estimating and the dateout of the fast fourier transform of the timing slip correction inphase/quadrature phase data of timing slip estimation module gained according to integer frequency offset; Control module, be used for estimating and timing slip estimation module, frequency deviation adjusting module and the work of time migration correcting module at the inclined to one side estimation module of acquisition phase control mark frequency multiplication, mark frequency multiplication deflection correction module, integer frequency offset, and in the inclined to one side estimation module of tracking phase control mark frequency multiplication, integer frequency offset estimation and timing slip estimation module, frequency deviation adjusting module and the work of time migration correcting module.

Technique scheme acquisition phase to the data that receive carry out that the mark frequency multiplication is estimated partially, mark frequency multiplication deflection correction, integer frequency offset is estimated and timing slip is estimated, according to the mark frequency multiplication estimate partially, integer frequency offset estimates to carry out frequency shift (FS) and corrects, estimate to carry out the time migration correction according to timing slip, finish the estimation and the compensation of accurate frequency shift (FS) and time migration thus; At tracking phase the data that receive are carried out mark frequency multiplication estimation and integer frequency offset estimation partially, estimate partially that according to the mark frequency multiplication carrying out frequency shift (FS) corrects, estimate to carry out the time migration correction according to timing slip, frequency shift (FS) and time migration are estimated in real time and compensated with this.What is more important, timing slip is estimated according to signal-to-noise ratio (SNR) estimation, be that timing slip estimates it is strong and weak adaptive according to signal strength signal intensity, therefore, technique scheme is applied in the digital audio broadcast receiver of portable terminal, when signal is more weak, or when the long-time program receiving of portable terminal, or at a high speed at portable terminal, add suddenly, during retarded motion (being that change in signal strength is fast), can demodulate high-quality digital audio broadcasting signal, and then also just improved the reception of portable terminal, so not only normal program receiving also can obtain to make customer satisfaction system reception.

For solving the problems of the technologies described above, the present invention also provides a kind of method for synchronous that is used for digital audio broadcast receiver, and described method comprises the steps:

(5) when receiving the phase reference symbol of data transmission frames, the dateout of the fast fourier transform of the inphase/quadrature phase data that receive is done the time migration correction according to the timing slip of step (3) gained.

Wherein, described method is used for carrying out described step (1) to (5) when receiving each data transmission frames.

Corresponding to above-mentioned method for synchronous, the present invention also provides a kind of synchronizer that is used for digital audio broadcast receiver, described device comprises: the inclined to one side estimation module of mark frequency multiplication is used for according to the inphase/quadrature phase data estimation mark frequency multiplication of the Cyclic Prefix of phase reference symbol inclined to one side; Mark frequency multiplication deflection correction module, be used for according to the mark frequency multiplication of the inclined to one side estimation module gained of mark frequency multiplication inclined to one side, the inphase/quadrature phase data that receive are carried out mark frequency multiplication deflection correction, will give the fast fourier transform of digital audio broadcast receiver/contrary fast fourier transform module through the inphase/quadrature phase data behind the mark frequency multiplication deflection correction again and carry out quick Fourier transformation computation; Integer frequency offset is estimated and the timing slip estimation module, is used for dateout estimation integer frequency offset and timing slip according to the fast fourier transform of signal to noise ratio and inphase/quadrature phase data; The frequency deviation adjusting module is used for according to the mark frequency multiplication of the inclined to one side estimation module gained of mark frequency multiplication partially and integer frequency offset is estimated and the intermediate frequency value of the digital controlled oscillator of the Digital Down Converter Module of the integer frequency offset adjustment digital audio broadcast receiver of timing slip estimation module gained; The time migration correcting module is used for estimating and the dateout of the fast fourier transform of the timing slip correction inphase/quadrature phase data of timing slip estimation module gained according to integer frequency offset; Control module is used to control the inclined to one side estimation module of mark frequency multiplication, mark frequency multiplication deflection correction module, integer frequency offset estimation and timing slip estimation module, frequency deviation adjusting module and the work of time migration correcting module.

Wherein, control module is used for the inclined to one side estimation module of control mark frequency multiplication, mark frequency multiplication deflection correction module, integer frequency offset estimation and timing slip estimation module, frequency deviation adjusting module and the work of time migration correcting module when receiving each data transmission frames.

Technique scheme to the data that receive carry out that the mark frequency multiplication is estimated partially, mark frequency multiplication deflection correction, integer frequency offset is estimated and timing slip is estimated, according to the mark frequency multiplication estimate partially, integer frequency offset estimates to carry out frequency shift (FS) and corrects, estimate to carry out the time migration correction according to timing slip, finish the estimation and the compensation of accurate frequency shift (FS) and time migration thus; What is more important, timing slip is estimated according to signal-to-noise ratio (SNR) estimation, be that timing slip estimates it is strong and weak adaptive according to signal strength signal intensity, therefore, technique scheme is applied in the digital audio broadcast receiver of portable terminal, when signal is more weak, or when the long-time program receiving of portable terminal, or at a high speed at portable terminal, add suddenly, during retarded motion (being that change in signal strength is fast), can demodulate high-quality digital audio broadcasting signal, and then also just improved the reception of portable terminal, so not only normal program receiving also can obtain to make customer satisfaction system reception.

Description of drawings

Fig. 1 is the schematic diagram of DAB data transmission frame structure in the time domain;

Fig. 2 is the form of each symbol in the DAB data transmission frames shown in Figure 1;

Fig. 3 is the basic procedure step of the first embodiment of the invention method for synchronous that is used for the DAB receiver;

Fig. 4 is the detailed process step of step S11 shown in Figure 3;

Fig. 5 is the detailed process step of step S13 shown in Figure 3;

Fig. 6 is the detailed process step of step S22 shown in Figure 3;

Fig. 7 is the structural representation of the synchronizer that is used for the DAB receiver of the embodiment of the invention;

Fig. 8 is a basic structure schematic diagram of using the DAB receiver of synchronizer shown in Figure 7.

Embodiment

Method for synchronous and the synchronizer that is used for the DAB receiver provided by the present invention, according to signal-to-noise ratio (SNR) estimation, promptly TO estimates it is strong and weak adaptive according to signal strength signal intensity to the estimation of TO for it.Before explanation the present invention is used for the method for synchronous and device of DAB receiver, at first need to carry out briefly bright to the structure of DAB data transmission frames.

The DAB signal transmits in time frame by frame, and these frames are called transmission frame, and transmission frame is made up of the OFDM symbol that several have different task and content.Because the complexity of receiving terminal geographical environment of living in, make the signal that receives that the main footpath signal of direct wave not only be arranged, also have from many different path signals that different buildings reflect and diffraction is come, and their signal strength signal intensities when arriving, carrier phase when the time of advent and arrival is all different, therefore received signal be above-mentioned each path signal vector and, that is to say, may produce self-interference between each path, this class self-interference is called multipath and disturbs, the multipath of channel disturbs and makes each subchannel of ofdm signal at receiving terminal quadrature no longer, will produce ICI and ISI.Disturb ICI and the ISI that causes in order to solve multipath, the DAB system has adopted Cyclic Prefix, and (CP, method CyclicPrefix) are about to each OFDM symbol decline and copy to the front of OFDM symbol as the protection interval.The DAB system provides four kinds of mode of operations, different DAB mode of operations have different frame lengths and frequency interval, different symbol quantities, but its frame structure is the same, and the structure of DAB data transmission frames is as shown in Figure 1 in the time domain, top null symbol (NULL) can be used for detecting the original position of data transmission frames in its frame structure, symbol 0 following closely is phase reference symbol (PRS), symbol 1 afterwards, symbol 2, ..., symbol N is a data symbol.PRS is the specified data that transmitting terminal and receiving terminal are known, and for the differential modulation of next OFDM symbol provides phase reference, also is used to detect simultaneously the time synchronized of Frame and OFDM symbol.The form of each symbol as shown in Figure 2; the content of protection interval T G (being Cyclic Prefix) is identical with the content of the end time T E of same symbol; just protect interval T G to have identical length with the end time T E of valid data, the data number that the data number that protection interval T G is comprised and the end time T E of valid data are comprised is identical.

Below in conjunction with accompanying drawing and preferred embodiment the specific embodiment of the present invention is described in detail.First embodiment

In the present embodiment, the method for synchronous that is used for the DAB receiver carries out FFO estimation, FFO correction, IFO estimation and TO at acquisition phase to the data that receive and estimates, estimating to carry out frequency shift (FS) according to FFO estimation, IFO corrects, estimate to carry out the time migration correction according to TO, finish the estimation and the compensation of accurate frequency shift (FS) and time migration thus; At tracking phase the data that receive are carried out that FFO estimates and TO estimates, estimate to carry out frequency shift (FS) according to FFO and correct,, frequency shift (FS) and time migration are estimated in real time and compensated with this according to TO estimation carrying out time migration correction.Wherein, TO estimates according to signal-to-noise ratio (SNR) estimation, and promptly TO estimates it is strong and weak adaptive according to signal strength signal intensity.

Described DAB receiver is used to receive the data transmission frames that comprises OFDM symbol, described data transmission frames comprises null symbol, phase reference symbol and data symbol, described phase reference symbol comprises Cyclic Prefix and valid data, described data symbol comprises Cyclic Prefix and valid data, obtains the inphase/quadrature phase data of base band behind analog-to-digital conversion, Digital Down Convert and the filtering extraction of described data transmission frames through the DAB receiver.

The method for synchronous of present embodiment as shown in Figure 3, it comprises acquisition phase S1 and tracking phase S2.

Described acquisition phase S1 is meant when receiving the first frame data transmission frame.Concrete steps such as Fig. 3 at first carry out step S11 to shown in Figure 5.

In step S11, according to the inphase/quadrature phase of the Cyclic Prefix (CP) of phase reference symbol (PRS) (I/Q, In-phase/Quadrature-phase) data estimation mark frequency multiplication (FFO) partially.Described I/Q data are that the data transmission frames that the DAB receiver receives obtains through behind analog-to-digital conversion (ADC), Digital Down Convert (DDS) and the filtering extraction.As shown in Figure 4, step S11 at first carries out step S111.

In step S111, clear 0 to counter A, set count value m and equal 0.Then carry out step S112.

In step S112, calculate m Cyclic Prefix correlation, whether the mould value of judging m Cyclic Prefix (CP) correlation is more than or equal to the mould value of predetermined largest loop prefix (CP) correlation threshold value, if the mould value of m CP correlation is more than or equal to the mould value of predetermined maximum CP correlation threshold value, then carry out step S115, if the mould value of m cyclic prefix CP correlation is then carried out step S113 less than the mould value of predetermined largest loop prefix CP correlation threshold value.The account form of described m CP correlation is as described below: get null symbol (NULL) end position and add M I/Q data behind the m position and NULL end position and add (M+L) behind m position M I/Q data after individual; and (M+L) M I/Q data after individual are got conjugation; each I/Q data after the conjugation take advantage of M I/Q data of corresponding beginning to add up then; wherein; M is the Cyclic Prefix length of (protection at interval), and L is the length of valid data.Described predetermined CP correlation threshold value is determined by emulation and test, it can be adjusted according to the actual reception situation, and the signal that receives when only searching the CP correlation more than or equal to predetermined maximum CP correlation threshold value just can be considered to useful signal.

In step S113, judge that count value m is whether greater than the length of Cyclic Prefix, if count value m is greater than the length of Cyclic Prefix, the CP correlation that does not search more than or equal to predetermined maximum CP correlation threshold value is described, what receive is incorrect signal, then is back to step S1, if count value m is smaller or equal to the length of Cyclic Prefix, then carry out step S114, continue to calculate next CP correlation.

In step S114, count value m equals m and adds 1, then is back to step S112.

In step S115, m CP correlation is made as maximum CP correlation, then carry out step S117.

In step S116, count value m equals m and adds 1, calculate m CP correlation, whether the mould value of judging m CP correlation is greater than the mould value of maximum CP correlation, if the mould value of m CP correlation is greater than the mould value of maximum CP correlation, then carry out step S117, if the mould value of m CP correlation is then carried out step S118 smaller or equal to the mould value of maximum CP correlation.Wherein, the account form of described m CP correlation is as described in the step S112.

In step S117, clear 0 to counter A, m CP correlation is made as maximum CP correlation, then be back to step S116.

In step S118, A adds 1 with counter, and whether the value of judging counter A is greater than predetermined count value, if whether the value of counter A is greater than predetermined count value, then carry out step S119, if whether the value of counter A then is back to step S116 smaller or equal to predetermined count value.Wherein, described predetermined count value is smaller or equal to the length of Cyclic Prefix.In the present embodiment, described predetermined count value is made as 32.

In step S119, according to maximum CP correlation value calculation FFO.The phase place of maximum CP correlation is exactly FFO, therefore, the maximum CP correlation that obtains in the abovementioned steps is done arc tangent (Arctan) computing to take out the phase value of maximum CP correlation, and described phase value is exactly FFO.End step S119 is end step S11, then carries out step S12.

In step S12, mark frequency multiplication inclined to one side (FFO) according to step S11 gained, inphase/quadrature phase (I/Q) data that receive are carried out mark frequency multiplication deflection correction (FFO Correction), again the I/Q data after correcting through FFO are carried out the fast Fourier transform (FFT) computing.In this step, the I/Q data that receive are carried out FFO correct and to be meant the I/Q data that receive are carried out phase correction, because various synchronism deviations all can cause the phase place rotation, if the data that send are z, because of there is phase place rotation θ in synchronism deviation, the data that then receive are ze ^{-j θ}Obviously, if correctly estimated this phase place rotation, as long as it be multiply by e ^{J θ}Just can correct it, i.e. z=ze ^{-j θ}* e ^{J θ}=z, wherein, phase place rotation θ promptly is resulting FFO among the step S11.Therefore, be input to the I/Q data that FFT carries out computing and do not have FFO, FFT can obtain correct operation result.Then carry out step S13.

In step S13, according to the dateout computes integer frequency multiplication of the fast Fourier transform (FFT) computing of signal to noise ratio and step S12 gained (IFO) and timing slip (TO) partially.As shown in Figure 5, step S13 at first carries out step S131.

In step S131, clear 0 to a counter B, calculate the signal energy summation of FFT dateout (the FFT dateout that obtains according to step S12).Signal energy is used for determining the power of received signal, and the output of FFT is that a data sequence x (n) is N a output point, and wherein, N is the length of FFT, so the signal energy summation of FFT dateout is

E = Σ_{0}^{N - 1} x (n) x^{*} (n) = Σ_{0}^{N - 1} {| x (n) |}^{2} .

Then carry out step S132.

In step S132, set count value k=1, then carry out step S133.

In step S133, the FFT dateout moved clockwise carry out contrary fast fourier transform (IFFT) computing and the dateout calculating energy all behind the k position IFFT, the maximum of energy wherein is designated as k maximum energy value; Carry out IFFT computing and the dateout calculating energy all after the FFT output valve moved the k position counterclockwise, the maximum of energy wherein is designated as the-k maximum energy value IFFT.For instance, the FFT dateout comprises N output point (0～(N-1)), the FFT dateout moved clockwise carry out inverse Fourier transform (IFFT) computing after 1 and be meant the 1st output point of FFT the 0th input point as IFFT, the 2nd output point of FFT is as the 1st input point of IFFT, ..., (N-1) individual output point of FFT is as (N-2) individual input point of IFFT, and the 0th output point of FFT is as (N-1) individual input point of IFFT; The FFT dateout moved counterclockwise carry out inverse Fourier transform (IFFT) computing after 1 and be meant (N-1) individual output point of FFT the 0th input point as IFFT, the 0th output point of FFT is as the 1st input point of IFFT, ..., (N-3) individual output point of FFT is as (N-2) individual input point of IFFT, and (N-2) individual output point of FFT is as (N-1) individual input point of IFFT.Then carry out step S134.

In step S134, B adds 1 with counter, and whether the value of judging counter B is greater than predetermined shift value.Described predetermined shift value is meant the estimation range of IFO, and promptly estimation and the compensation to frequency shift (FS) can realize normal the reception in this estimation range, and described estimation range can be-128 to 127.In the actual receiver, the scope of frequency shift (FS) depends on the oscillator parts technical indicator that is adopted, the frequency range of system works, and the interval between the subcarrier of used FFT etc., the estimation range of IFO is-64 to 64 in the present embodiment, and therefore, described predetermined shift value is 64.If whether the value of counter B then carries out step S136 greater than predetermined shift value; If the value of counter B is then carried out step S135 smaller or equal to predetermined shift value.

In step S135, carry out the calculating of k=k+1, then be back to step S133.

In step S136, compare each maximum energy value, just compare the 1st to the 64th maximum energy value and the-1 to-64 maximum energy value, find out the maximum of all maximum energy value, and judge whether described maximum calculates the signal energy summation of gained and the product of a coefficient greater than step S131, wherein, described coefficient is SNR/ (1+SNR), SNR is a signal to noise ratio, it can require to determine according to actual reception, for example, the signal to noise ratio snr that meets the DAB national standard is more than the 6db.In the present embodiment, described signal to noise ratio snr is the ratio of useful signal and noise signal, useful signal is the maximum of maximum energy value, noise signal is the peaked difference of signal energy summation and maximum energy value, and can derive the maximum of maximum energy value and the ratio of signal energy summation thus is SNR/ (1+SNR).If the maximum of described maximum energy value, illustrates that the signal that receives this moment is more intense greater than the product of signal energy summation and SNR/ (1+SNR), then carry out step S137; If the maximum of described maximum energy value smaller or equal to the product of signal energy summation and SNR/ (1+SNR), illustrates a little less than the signal that receives this moment, is incorrect signal, need carry out the step of acquisition phase again, therefore be back to step S1.

In step S137, the pairing shift value of the peaked maximum of described energy be k or-the k value is exactly IFO, the outgoing position of corresponding IFFT is exactly TO.For instance, maximum is the 50th the energy maximum that step S133 calculates, so IFO is exactly 50, and this energy maximum to be the 200th output point of the IFFT (the 50th IFFT computing) according to correspondence calculate, therefore, the value of TO is 200.End step S137 is end step S13, and in step S13, IFO and TO are adaptive according to signal to noise ratio, then carries out step S14.

In step S14, with integer frequency offset (IFO) and mark frequency multiplication partially (FFO) digital controlled oscillator (NCO) of sending into Digital Down Convert (DDS) go to adjust the intermediate frequency value of NCO.At this moment, the intermediate frequency value before adjusted intermediate frequency value equals to adjust adds ((IFO+FFO) * frequency interval), and described frequency interval is according to the DAB mode of operation and definite.The intermediate frequency value of adjusting NCO can be to carry out at each symbol that receives data transmission frames, and in the present embodiment, the intermediate frequency value of adjusting NCO is to carry out when receiving the null symbol of data transmission frames.Then carry out step S15.

In step S15, when receiving the phase reference symbol (PRS) of data transmission frames, according to the timing slip (TO) of step S13 gained the dateout of the FFT of inphase/quadrature phase (I/Q) data that receive is done the time migration correction, it is the phase place that step value increases that the dateout that is about to FFT multiply by with TO.The dateout of described FFT is meant the dateout of data transmission frames behind ADC, DDS, filtering extraction and FFT that the DAB receiver receives, and revised data are then proceeded differential ference spiral.Concrete correcting mode is as described below: if uncorrected data are z _i=x _i+ jy _i, then revised data are z _i=x _iCos (2 π * TO*i/FFTlength)+jy _iSin (2 π * TO*i/FFTlength), wherein FFTlength is the sub-carrier number of FFT, 0＜i＜FFTlength; In the following formula, the value in the bracket is that the increase with i is that step value increases with TO.

Behind end step S15, promptly finished acquisition phase S1, then entered tracking phase S2, when described tracking phase S2 is meant each data transmission frames after receiving the first frame data transmission frame.Concrete steps such as Fig. 3 and shown in Figure 6 at first carry out step S21.

In step S21, according to the inphase/quadrature phase of the Cyclic Prefix (CP) of phase reference symbol (PRS) and data symbol (I/Q, In-phase/Quadrature-phase) data estimation mark frequency multiplication (FFO) partially.This step step S111 to S119 of step S11 substantially as described above is described, refuse repeat specification at this, different is, step S11 is the I/Q data estimation FFO according to the CP of PRS, step S21 is the I/Q data estimation FFO according to the CP of each symbol (PRS and data symbol), therefore the account form of wherein calculating m Cyclic Prefix correlation is as described below: get previous sign-off position and add (M+L) individual M inphase/quadrature phase data afterwards after M inphase/quadrature phase data behind the m position and previous sign-off position add the m position, and (M+L) M inphase/quadrature phase data after individual are got conjugation, each inphase/quadrature phase data after the conjugation take advantage of M inphase/quadrature phase data of corresponding beginning to add up then, wherein, M is the length of Cyclic Prefix, and L is the length of valid data.Then carry out step S22.

In step S22, estimate timing slip (TO) according to the signal energy of the dateout of the fast Fourier transform (FFT) computing of signal to noise ratio and inphase/quadrature phase (I/Q) data.As shown in Figure 6, step S22 at first carries out step S221.

In step S221, calculate the signal energy summation of FFT dateout.Signal energy is used for determining the power of received signal, and the output of FFT is that a data sequence x (n) is N continuous data, and wherein, N is the length of FFT, so the signal energy summation of FFT output is

E = Σ_{0}^{N - 1} x (n) x^{*} (n) = Σ_{0}^{N - 1} {| x (n) |}^{2} .

Then carry out step S222.

In step S222, the FFT dateout is carried out the IFFT computing, all to IFFT then dateout calculating energies are looked for energy maximum wherein, and judge whether described energy maximum calculates the energy summation of gained and the product of a coefficient greater than step S221, wherein, described coefficient is SNR/ (1+SNR), and SNR is a signal to noise ratio, and it can require to determine according to actual reception, for example, the signal to noise ratio snr that meets the DAB national standard is more than the 6db.In the present embodiment, described signal to noise ratio snr is the ratio of useful signal and noise signal, useful signal is the energy maximum, and noise signal is signal energy summation and the peaked difference of energy, and the ratio that can derive energy maximum and signal energy summation thus is SNR/ (1+SNR).If described energy maximum, illustrates that the signal that receives this moment is stronger greater than the product of signal energy summation and SNR/ (1+SNR), then carry out step S233.If the signal that described energy maximum, illustrate reception at this moment smaller or equal to the product of energy summation and coefficient a little less than, then carry out step S224.

In step S223, the outgoing position of the pairing IFFT of described energy maximum is decided to be TO.For instance, the energy maximum is that the 200th output point according to IFFT calculates, and therefore, then the value of TO is 200.Then carry out step S23.

In step S224, TO mean value is decided to be TO, described TO mean value is meant that each determined TO is averaged calculating to be obtained.Under the more weak situation of signal, the TO value that estimates is insecure or even wrong, so by the mode of signal energy comparison being determined whether the TO value that estimates is reliable.If unreliable, then replace, because the variation of TO is slowly, so this replacement is feasible with the TO mean value of estimating before.Be accompanied by the calculating of each TO like this, all will average calculating, use when more weak in order to signal to reliable TO.From step S223 and S224 as can be known, TO is adaptive according to signal to noise ratio, that is to say, when signal was strong, TO directly estimated according to received signal, and when signal is more weak, the TO mean value of estimating before TO gets.Then carry out step S23.

In step S23, with the mark frequency multiplication partially (FFO) digital controlled oscillator (NCO) of sending into the Digital Down Convert (DDS) of digital audio broadcast receiver go to adjust the intermediate frequency value of NCO.At this moment, the intermediate frequency value before adjusted intermediate frequency value equals to adjust adds (FFO* frequency interval).Described frequency interval is according to the DAB mode of operation and definite.The intermediate frequency value of adjusting NCO can be to carry out at each symbol that receives data transmission frames, and in the present embodiment, the intermediate frequency value of adjusting NCO is to carry out when receiving the null symbol of data transmission frames.Then carry out step S24.

In step S24, when receiving the phase reference symbol (PRS) of each data transmission frames, the dateout of the FFT of inphase/quadrature phase (I/Q) data that receive is done the time migration correction, it is the phase place that step value increases that the output that is about to FFT be multiply by with TO.The dateout of described FFT is meant the data transmission frames of DAB receiver reception through the dateout behind ADC, DDS, filtering extraction and the FFT, and revised data are then proceeded differential ference spiral.Step S15 is described as described above for concrete correcting mode, refuses repeat specification at this.Then carry out step S25.

In step S25, continue to receive the next frame data transmission frames, then be back to step S21, promptly frequency shift (FS) and time migration are estimated in real time and compensated.

Corresponding to above-mentioned method for synchronous, the present invention also provides a kind of synchronizer of the DAB of being used for receiver, described DAB receiver is used to receive the data transmission frames that comprises the OFDM symbol, described data transmission frames comprises NULL, PRS and data symbol, described PRS comprises CP and valid data, described data symbol comprises CP and valid data, described data transmission frames is through the ADC module of DAB receiver, obtain the I/Q data of base band after DDS module and the filtering extraction module, as shown in Figure 7, described synchronizer 7 comprises the inclined to one side estimation module 71 of mark frequency multiplication, mark frequency multiplication deflection correction module 72, integer frequency offset is estimated and timing estimation module 73, frequency deviation adjusting module 74, time migration correcting module 75 and control module 76.

The mark frequency multiplication is (FFO) estimation module 71 partially, is used for the I/Q data computation FFO according to the CP of PRS and data symbol.

Mark frequency multiplication (FFO) is partially corrected module 72, is used for the FFO according to FFO estimation module 71 gained, the I/Q data that receive is carried out FFO correct, and the I/Q data after will correcting through FFO are again given the FFT/IFFT module 84 of DAB receiver and carried out the FFT computing.

Integer frequency offset (IFO) is estimated and timing slip (TO) estimation module 73, is used for dateout calculating IFO and TO according to the FFT of signal to noise ratio and I/Q data.

Frequency deviation adjusting module 74 is used for according to the FFO of FFO estimation module 71 gained and IFO estimates and the intermediate frequency value of the NCO of the DDS module of the IFO adjustment DAB receiver of TO estimation module 73 gained.

Time migration correcting module 75 is used for estimating and the dateout of the FFT of the TO correction I/Q data of TO estimation module 73 gained according to IFO.

Control module 76, be used for controlling FFO estimation module 71, FFO correction module 72, IFO estimation and TO estimation module 73, frequency deviation adjusting module 74 and 75 work of time migration correcting module, and work at tracking phase control FFO estimation module 71, IFO estimation and TO estimation module 73, frequency deviation adjusting module 74 and time migration correcting module 75 at acquisition phase.Described acquisition phase is meant when receiving the first frame data transmission frame, when described tracking phase is meant each data transmission frames after receiving the first frame data transmission frame.

Synchronizer 7 provided by the present invention can be embedded in a DAB receiver, and the logical design scheme of described synchronizer 7 is described below in conjunction with Fig. 7 and Fig. 8:

At acquisition phase, promptly when receiving the first frame data transmission frame, obtain the FFO estimation module 71 that the I/Q data are sent into synchronizer 7 after ADC module 81, DDS module 82 and the filtering extraction module 83 of data transmission frames through the DAB receiver, control module 76 starts FFO estimation module 71, FFO estimation module 71 is according to the I/Q data computation FFO of the CP of PRS, and concrete account form is as described in the step S111 to S119 in the above-mentioned method for synchronous; Then control module 76 starts FFO correction module 72, FFO corrects the FFO of module 72 according to FFO estimation module 71 gained, the I/Q data that receive are carried out FFO corrects, I/Q data after will correcting through FFO are again given the FFT/IFFT module 84 of DAB receiver and are carried out the FFT computing, and the mode of specifically correcting is as described in the step S12 in the above-mentioned method for synchronous; Then control module 76 starts IFO estimation and TO estimation module 73, IFO estimates and TO estimation module 73 is calculated IFO and TO according to the dateout that signal to noise ratio and FFO correct the FFT of the I/Q data after module 72 is corrected, and specifically account form is as described in the step S131 to S137 in the above-mentioned method for synchronous; Then control module 76 starts frequency deviation adjusting module 74, frequency deviation adjusting module 74 is when the NULL of data transmission frames, according to the FFO of FFO estimation module 71 gained with IFO estimates and the intermediate frequency value of the NCO of the IFO adjustment DDS module 82 of TO estimation module gained, the mode of specifically adjusting is as described in the step S14 in the above-mentioned method for synchronous; Then control module offset correction module 76 start-up time 75, time migration correcting module 75 are estimated according to IFO and the TO of TO estimation module gained revises the dateout of the FFT of I/Q data, and specifically correcting mode is as described in the step S15 in the above-mentioned method for synchronous.

At tracking phase, promptly during each data transmission frames after receiving the first frame data transmission frame, obtain the I/Q data after ADC module 81, DDS module 82 and the filtering extraction module 83 of data transmission frames through the DAB receiver and send into synchronizer 7, control module 76 starts FFO estimation module 71, FFO estimation module 71 is according to the I/Q data computation FFO of the CP of PRS and data symbol, and concrete account form is as described in the step S21 in the above-mentioned method for synchronous; Then control module 76 starts IFO estimation and TO estimation module 73, IFO estimates and TO estimation module 73 is calculated TO according to signal to noise ratio and the dateout of FFT of sending into the I/Q data of synchronizer 7, and specifically account form is as described in the step S221 to S224 in the above-mentioned method for synchronous; Then control module 76 starts frequency deviation adjusting module 74, frequency deviation adjusting module 74 is when the NULL of data transmission frames, adjust the intermediate frequency value of the NCO of DDS module 82 according to the FFO of FFO estimation module 71 gained, the mode of specifically adjusting is as described in the step S23 in the above-mentioned method for synchronous; Then control module offset correction module 76 start-up time 75, time migration correcting module 75 are estimated according to IFO and the TO of TO estimation module gained revises the dateout of the FFT of I/Q data, and specifically correcting mode is as described in the step 24 in the above-mentioned method for synchronous; Then, the DAB receiver continues to receive the next frame data transmission frames, and control module 76 restarts FFO estimation module 71.

After the dateout after ADC module 81, DDS module 82, filtering extraction module 83 and the FFT/IFFT module 84 of 75 pairs of data transmission frames processes of time migration correcting module DAB of acquisition phase and tracking phase receiver is revised, revised data are sent into the differential ference spiral module 85 of DAB receiver, separate mapping block 87, time de-interweaving module 88 and Viterbi (Viterbi) decoder 89 through overfrequency de-interleaving block 86, quadriphase PSK (QPSK) then and promptly can demodulate high-quality DAB signal.

In sum, the method for synchronous of the described DAB of the being used for receiver of present embodiment and synchronizer carry out FFO estimation, FFO correction, IFO estimation and TO at acquisition phase to the data that receive and estimate, estimating to carry out frequency shift (FS) according to FFO estimation, IFO corrects, estimate to carry out the time migration correction according to TO, finish the estimation and the compensation of accurate frequency shift (FS) and time migration thus; At tracking phase the data that receive are carried out that FFO estimates and TO estimates, estimate to carry out frequency shift (FS) according to FFO and correct,, frequency shift (FS) and time migration are estimated in real time and compensated with this according to TO estimation carrying out time migration correction.What is more important, TO estimates according to signal-to-noise ratio (SNR) estimation, be that TO estimates it is strong and weak adaptive according to signal strength signal intensity, therefore, the described technical scheme of present embodiment is applied in the DAB receiver of portable terminal, when signal is more weak, or when the long-time program receiving of portable terminal, or at a high speed at portable terminal, add suddenly, during retarded motion (being that change in signal strength is fast), can demodulate high-quality DAB signal, and then also just improved the reception of portable terminal, so not only normal program receiving also can obtain to make customer satisfaction system reception.

In addition,, promptly need not to carry out again FFO correction and IFO estimation, therefore simplified synchronous process, reduced hard-wired complexity at tracking phase owing to estimation and the compensation of having finished accurate frequency shift (FS) and time migration at acquisition phase.

Second embodiment

The difference of present embodiment and the described method for synchronous of first embodiment is: the method for synchronous of first embodiment is divided into acquisition phase and tracking phase, acquisition phase is when receiving the first frame data transmission frame data that receive to be carried out FFO estimation, FFO correction, IFO estimation and TO to estimate, estimating to carry out frequency shift (FS) according to FFO estimation, IFO corrects, estimate to carry out the time migration correction according to TO, finish the estimation and the compensation of accurate frequency shift (FS) and time migration thus; When tracking phase is each data transmission frames after receiving the first frame data transmission frame data that receive are carried out that FFO estimates and the TO estimation, estimating to carry out frequency shift (FS) according to FFO corrects, estimate to carry out the time migration correction according to TO, frequency shift (FS) and time migration are estimated in real time and compensated with this.Wherein, TO estimates according to signal-to-noise ratio (SNR) estimation, and promptly TO estimates it is strong and weak adaptive according to signal strength signal intensity.The method for synchronous of present embodiment is not distinguished acquisition phase and tracking phase, estimate but when receiving each data transmission frames, the data that receive are carried out FFO estimation, FFO correction, IFO estimation and TO, estimating to carry out frequency shift (FS) according to FFO estimation, IFO corrects, estimate to carry out the time migration correction according to TO, frequency shift (FS) and time migration are carried out accurately and in real time estimating and compensating with this.

Therefore, when receiving each data transmission frames, the described method for synchronous of the present embodiment in fact acquisition phase with the described method for synchronous of first embodiment is identical, and it comprises the steps:

Inphase/quadrature phase data estimation mark frequency multiplication according to the Cyclic Prefix of phase reference symbol is inclined to one side, as described in the step S11 of first embodiment;

Mark frequency multiplication according to step S11 gained is inclined to one side, the inphase/quadrature phase data that receive are carried out mark frequency multiplication deflection correction, again to carrying out quick Fourier transformation computation, as described in the step S12 of first embodiment through the inphase/quadrature phase data behind the mark frequency multiplication deflection correction;

Dateout according to the quick Fourier transformation computation of signal to noise ratio and step S12 gained is estimated integer frequency offset and timing slip, as described in the step S13 of first embodiment;

The digital controlled oscillator that the mark frequency multiplication of the integer frequency offset of step S13 gained and step S11 gained is sent into the Digital Down Convert of digital audio broadcast receiver partially goes to adjust the intermediate frequency value of digital controlled oscillator, as described in the step S14 of first embodiment;

When receiving the phase reference symbol of data transmission frames, according to the timing slip of step S13 gained the dateout of the fast fourier transform of the inphase/quadrature phase data that receive is done the time migration correction, as described in the step S15 of first embodiment.

After executing above-mentioned steps, continue to receive the next frame data transmission frames, repeat above-mentioned steps (i.e. the step S11 to S15 of first embodiment) then.

The mark frequency multiplication is (FFO) estimation module 71 partially, is used for the I/Q data computation FFO according to the CP of PRS.

Control module 76 is used to control FFO estimation module 71, FFO correction module 72, IFO estimation and TO estimation module 73, frequency deviation adjusting module 74 and 75 work of time migration correcting module.

When receiving each data transmission frames, obtain the FFO estimation module 71 that the I/Q data are sent into synchronizer 7 after ADC module 81, DDS module 82 and the filtering extraction module 83 of data transmission frames through the DAB receiver, control module 76 starts FFO estimation module 71, FFO estimation module 71 is according to the I/Q data computation FFO of the CP of PRS, and concrete account form is as described in the step S11 of first embodiment; Then control module 76 starts FFO correction module 72, FFO corrects the FFO of module 72 according to FFO estimation module 71 gained, the I/Q data that receive are carried out FFO corrects, I/Q data after will correcting through FFO are again given the FFT/IFFT module 84 of DAB receiver and are carried out the FFT computing, and the mode of specifically correcting is as described in the step S12 of first embodiment; Then control module 76 starts IFO estimation and TO estimation module 73, IFO estimates and TO estimation module 73 is calculated IFO and TO according to the dateout that signal to noise ratio and FFO correct the FFT of the I/Q data after module 72 is corrected, and specifically account form is as described in the step S13 of first embodiment; Then control module 76 starts frequency deviation adjusting module 74, frequency deviation adjusting module 74 is when the NULL of data transmission frames, according to the FFO of FFO estimation module 71 gained with IFO estimates and the intermediate frequency value of the NCO of the IFO adjustment DDS module 82 of TO estimation module gained, the mode of specifically adjusting is as described in the step S14 of first embodiment; Then control module offset correction module 76 start-up time 75, time migration correcting module 75 are estimated according to IFO and the TO of TO estimation module gained revises the dateout of the FFT of I/Q data, and specifically correcting mode is as described in the step S15 of above-mentioned first embodiment; Then, the DAB receiver continues to receive the next frame data transmission frames, and control module 76 restarts FFO estimation module 71.

After dateout after ADC module 81, DDS module 82, filtering extraction module 83 and the FFT/IFFT module 84 of 75 pairs of data transmission frames processes of time migration correcting module DAB receiver is revised, revised data are sent into the differential ference spiral module 85 of DAB receiver, separate mapping block 87, time de-interweaving module 88 and Viterbi (Viterbi) decoder 89 through overfrequency de-interleaving block 86, quadriphase PSK (QPSK) then and promptly can demodulate high-quality DAB signal.

In sum, present embodiment is described to be used for the method for synchronous of DAB receiver and device when receiving each data transmission frames, the data that receive are carried out FFO estimation, FFO correction, IFO estimation and TO to be estimated, estimating to carry out frequency shift (FS) according to FFO estimation, IFO corrects, estimate to carry out the time migration correction according to TO, frequency shift (FS) and time migration are carried out accurately and in real time estimating and compensating with this.What is more important, TO estimates according to signal-to-noise ratio (SNR) estimation, be that TO estimates it is strong and weak adaptive according to signal strength signal intensity, therefore, the described technical scheme of present embodiment is applied in the DAB receiver of portable terminal, when signal is more weak, or when the long-time program receiving of portable terminal, or at a high speed at portable terminal, add suddenly, during retarded motion (being that change in signal strength is fast), can demodulate high-quality DAB signal, and then also just improved the reception of portable terminal, so not only normal program receiving also can obtain to make customer satisfaction system reception.

Though the present invention with preferred embodiment openly as above; but it is not to be used for limiting the present invention; any those skilled in the art without departing from the spirit and scope of the present invention; can make possible change and modification, so protection scope of the present invention should be as the criterion with the scope that claim of the present invention was defined.

Claims

1. a method for synchronous that is used for digital audio broadcast receiver is characterized in that, described method comprises acquisition phase and tracking phase, wherein,

Described acquisition phase comprises the steps:

Described tracking phase comprises the steps:

2. method for synchronous according to claim 1 is characterized in that, described acquisition phase is meant when receiving the first frame data transmission frame.

3. method for synchronous according to claim 1 and 2 is characterized in that, the inclined to one side step (1) of inphase/quadrature phase data estimation mark frequency multiplication of described Cyclic Prefix according to phase reference symbol comprises the steps:

(1-1) clear 0 to counter A, set count value m and equal 0;

(1-2) calculate m Cyclic Prefix correlation, whether the mould value of judging m Cyclic Prefix correlation more than or equal to the mould value of the largest loop prefix correlation threshold value of being scheduled to, if, then carry out step (1-5), if not, then carry out step (1-3);

(1-3) judge count value m whether greater than the length of Cyclic Prefix, if, then be back to step (1), if not, then carry out step (1-4);

(1-4) count value m equals m and adds 1, is back to step (1-2);

(1-5) m Cyclic Prefix correlation is made as largest loop prefix correlation;

(1-6) count value m equals m and adds 1, calculates m Cyclic Prefix correlation, and whether the mould value of judging m Cyclic Prefix correlation greater than the mould value of largest loop prefix correlation, if, then carry out step (1-7), if not, then carry out step (1-8);

(1-7) clear 0 to counter A, m Cyclic Prefix correlation is made as largest loop prefix correlation, be back to step (1-6);

(1-8) counter A is added 1, and the value of judging counter A is whether greater than predetermined count value, if, then carry out step (1-9), if not, then be back to step (1-6);

(1-9) inclined to one side according to largest loop prefix correlation value calculation mark frequency multiplication.

4. method for synchronous according to claim 3, it is characterized in that, the account form of described m Cyclic Prefix correlation is as described below: get the null symbol end position and add M inphase/quadrature phase data behind the m position and null symbol end position and add (M+L) behind m position M inphase/quadrature phase data after individual, and (M+L) M inphase/quadrature phase data after individual are got conjugation, each inphase/quadrature phase data after the conjugation take advantage of M inphase/quadrature phase data of corresponding beginning to add up then, wherein, M is the length of Cyclic Prefix, and L is the length of valid data.

5. method for synchronous according to claim 3 is characterized in that, described predetermined count value is smaller or equal to the length of Cyclic Prefix.

6. method for synchronous according to claim 5 is characterized in that, described predetermined count value is 32.

7. method for synchronous according to claim 3 is characterized in that, described mark frequency multiplication is described largest loop prefix correlation to be done the phase value of the largest loop prefix correlation that arctangent cp cp operation takes out partially.

8. method for synchronous according to claim 1 and 2 is characterized in that, the described step (2) that the inphase/quadrature phase data that receive are carried out mark frequency multiplication deflection correction is that the inphase/quadrature phase data be multiply by e ^{J θ}, wherein, θ is that the mark frequency multiplication of step (1) gained is inclined to one side.

9. method for synchronous according to claim 1 and 2 is characterized in that, described dateout according to signal to noise ratio and quick Fourier transformation computation estimates that the step (3) of integer frequency offset and timing slip comprises the steps:

(3-1) clear 0 to a counter B, calculate the signal energy summation of fast fourier transform dateout;

(3-2) set count value k and equal 1;

(3-3) the fast fourier transform dateout is moved clockwise carry out contrary quick Fourier transformation computation behind the k position and the contrary all dateout calculating energies of fast fourier transform, the maximum of energy wherein is designated as k maximum energy value, the fast fourier transform dateout moved counterclockwise carry out contrary quick Fourier transformation computation behind the k position and, the maximum of energy wherein is designated as the-k maximum energy value the contrary all dateout calculating energies of fast fourier transform;

(3-4) counter B is added 1, and the value of judging counter B is whether greater than predetermined shift value, wherein said predetermined shift value is meant the estimation range of integer frequency offset, if, then carry out step (3-6), if not, then carry out step (3-5);

(3-5) count value k equals k and adds 1, is back to step (3-3);

(3-6) compare each energy maximum, find out the peaked maximum of all energy and judge that whether it is greater than the signal energy summation of step (3-1) gained and the product of SNR/ (1+SNR), wherein, SNR is a signal to noise ratio, if then carry out step (3-7), if not, then return step (1);

(3-7) with the pairing shift value of the peaked maximum of described energy be k or-the k value is decided to be integer frequency offset, the outgoing position of corresponding contrary fast fourier transform is decided to be timing slip.

10. method for synchronous according to claim 9 is characterized in that, the span of described predetermined shift value is 0 to 128.

11. method for synchronous according to claim 10 is characterized in that, described predetermined shift value is 64.

12. method for synchronous according to claim 1 and 2, it is characterized in that the intermediate frequency value that the digital controlled oscillator of integer frequency offset and mark frequency multiplication being sent into partially Digital Down Convert of described step (4) removes to adjust digital controlled oscillator is meant that the intermediate frequency value before adjusted intermediate frequency value equals to adjust adds the product of integer frequency offset and inclined to one side sum of mark frequency multiplication and frequency interval.

13. method for synchronous according to claim 1 and 2, it is characterized in that the intermediate frequency value that the digital controlled oscillator of integer frequency offset and mark frequency multiplication being sent into partially Digital Down Convert of described step (4) removes to adjust digital controlled oscillator is to carry out when receiving the null symbol of data transmission frames.

14. method for synchronous according to claim 1 and 2, it is characterized in that according to timing slip the dateout of the fast fourier transform of the inphase/quadrature phase data that receive being done the time migration correction and be meant that it is the phase place that step value increases that dateout with fast fourier transform multiply by with the timing slip of described step (5).

15. method for synchronous according to claim 1 is characterized in that, when described tracking phase is meant each data transmission frames after receiving the first frame data transmission frame.

16., it is characterized in that the inclined to one side step (6) of inphase/quadrature phase data estimation mark frequency multiplication of described Cyclic Prefix according to phase reference symbol and data symbol comprises the steps: according to claim 1 or 15 described method for synchronous

(6-1) clear 0 to counter A, set count value m and equal 0;

(6-2) calculate m Cyclic Prefix correlation, whether the mould value of judging m Cyclic Prefix correlation more than or equal to the mould value of the largest loop prefix correlation threshold value of being scheduled to, if, then carry out step (6-5), if not, then carry out step (6-3);

(6-3) judge count value m whether greater than the length of Cyclic Prefix, if, then be back to step (1), if not, then carry out step (6-4);

(6-4) count value m equals m and adds 1, is back to step (6-2);

(6-5) m Cyclic Prefix correlation is made as largest loop prefix correlation;

(6-6) count value m equals m and adds 1, calculates m Cyclic Prefix correlation, and whether the mould value of judging m Cyclic Prefix correlation greater than the mould value of largest loop prefix correlation, if, then carry out step (6-7), if not, then carry out step (6-8);

(6-7) clear 0 to counter A, m Cyclic Prefix correlation is made as largest loop prefix correlation, be back to step (6-6);

(6-8) counter A is added 1, and the value of judging counter A is whether greater than predetermined count value, if, then carry out step (6-9), if not, then be back to step (6-6);

(6-9) inclined to one side according to largest loop prefix correlation value calculation mark frequency multiplication.

17. method for synchronous according to claim 16, it is characterized in that, the account form of described m Cyclic Prefix correlation is as described below: get previous sign-off position and add M inphase/quadrature phase data behind the m position and previous sign-off position and add (M+L) behind m position M inphase/quadrature phase data after individual, and (M+L) M inphase/quadrature phase data after individual are got conjugation, each inphase/quadrature phase data after the conjugation take advantage of M inphase/quadrature phase data of corresponding beginning to add up then, wherein, M is the length of Cyclic Prefix, and L is the length of valid data.

18. method for synchronous according to claim 16 is characterized in that, described predetermined count value is smaller or equal to the length of Cyclic Prefix.

19. method for synchronous according to claim 18 is characterized in that, described predetermined count value is 32.

20. method for synchronous according to claim 16 is characterized in that, described mark frequency multiplication is described largest loop prefix correlation to be done the phase value of the largest loop prefix correlation that arctangent cp cp operation takes out partially.

21., it is characterized in that the dateout of described quick Fourier transformation computation according to signal to noise ratio and inphase/quadrature phase data estimates that the step (7) of timing slip comprises the steps: according to claim 1 or 15 described method for synchronous

(7-1) the signal energy summation of calculating fast fourier transform dateout;

(7-2) the fast fourier transform dateout is carried out contrary quick Fourier transformation computation, and to the contrary all dateout calculating energies of fast fourier transform, look for energy maximum wherein, and whether judge described energy maximum greater than the signal energy summation of step (7-1) gained and the product of SNR/ (1+SNR), wherein, SNR is a signal to noise ratio, if, then carry out step (7-3), if not, then carry out step (7-4);

(7-3) outgoing position with the pairing contrary fast fourier transform of described energy maximum is decided to be timing slip, end step (7);

(7-4) timing slip mean value is decided to be timing slip, described timing slip mean value is meant that each determined timing slip is averaged calculating to be obtained.

22. according to claim 1 or 15 described method for synchronous, it is characterized in that the intermediate frequency value that the digital controlled oscillator of the mark frequency multiplication being sent into partially Digital Down Convert of described step (8) removes to adjust digital controlled oscillator is meant that the intermediate frequency value before adjusted intermediate frequency value equals to adjust adds that the mark frequency multiplication partially and the product of frequency interval.

23., it is characterized in that the intermediate frequency value that the digital controlled oscillator of the mark frequency multiplication being sent into partially Digital Down Convert of described step (8) removes to adjust digital controlled oscillator is to carry out according to claim 1 or 15 described method for synchronous when receiving the null symbol of data transmission frames.

24. according to claim 1 or 15 described method for synchronous, it is characterized in that according to timing slip the dateout of the fast fourier transform of the inphase/quadrature phase data that receive being done the time migration correction and be meant that it is the phase place that step value increases that dateout with fast fourier transform multiply by with the timing slip of described step (9).

25. a synchronizer that is used for digital audio broadcast receiver is characterized in that the course of work of described device comprises acquisition phase and tracking phase, described device comprises:

The inclined to one side estimation module of mark frequency multiplication is used for according to the inphase/quadrature phase data estimation mark frequency multiplication of the Cyclic Prefix of phase reference symbol and data symbol inclined to one side;

Mark frequency multiplication deflection correction module, be used for according to the mark frequency multiplication of the inclined to one side estimation module gained of mark frequency multiplication inclined to one side, the inphase/quadrature phase data that receive are carried out mark frequency multiplication deflection correction, will give the fast fourier transform of digital audio broadcast receiver/contrary fast fourier transform module through the inphase/quadrature phase data behind the mark frequency multiplication deflection correction again and carry out quick Fourier transformation computation;

Integer frequency offset is estimated and the timing slip estimation module, is used for dateout estimation integer frequency offset and timing slip according to the fast fourier transform of signal to noise ratio and inphase/quadrature phase data;

The frequency deviation adjusting module is used for according to the mark frequency multiplication of the inclined to one side estimation module gained of mark frequency multiplication partially and integer frequency offset is estimated and the intermediate frequency value of the digital controlled oscillator of the Digital Down Converter Module of the integer frequency offset adjustment digital audio broadcast receiver of timing slip estimation module gained;

The time migration correcting module is used for estimating and the dateout of the fast fourier transform of the timing slip correction inphase/quadrature phase data of timing slip estimation module gained according to integer frequency offset;

Control module, be used for estimating and timing slip estimation module, frequency deviation adjusting module and the work of time migration correcting module at the inclined to one side estimation module of acquisition phase control mark frequency multiplication, mark frequency multiplication deflection correction module, integer frequency offset, and in the inclined to one side estimation module of tracking phase control mark frequency multiplication, integer frequency offset estimation and timing slip estimation module, frequency deviation adjusting module and the work of time migration correcting module.

26. synchronizer according to claim 25 is characterized in that, described acquisition phase is meant when receiving the first frame data transmission frame.

27. according to claim 25 or 26 described synchronizers, it is characterized in that, the inclined to one side estimation module of described mark frequency multiplication is inclined to one side according to the inphase/quadrature phase data estimation mark frequency multiplication of the Cyclic Prefix of phase reference symbol at acquisition phase, and the logical design scheme of the inclined to one side estimation module of described mark frequency multiplication is as described below:

(1-1) clear 0 to counter A, set count value m and equal 0;

(1-3) judge count value m whether greater than the length of Cyclic Prefix, if, then be back to acquisition phase, if not, then carry out step (1-4);

(1-4) count value m equals m and adds 1, is back to step (1-2);

(1-5) m Cyclic Prefix correlation is made as largest loop prefix correlation;

28. synchronizer according to claim 27, it is characterized in that, the account form of described m Cyclic Prefix correlation is as described below: get the null symbol end position and add M inphase/quadrature phase data behind the m position and null symbol end position and add (M+L) behind m position M inphase/quadrature phase data after individual, and (M+L) M inphase/quadrature phase data after individual are got conjugation, each inphase/quadrature phase data after the conjugation take advantage of M inphase/quadrature phase data of corresponding beginning to add up then, wherein, M is the length of Cyclic Prefix, and L is the length of valid data.

29. synchronizer according to claim 27 is characterized in that, described predetermined count value is smaller or equal to the length of Cyclic Prefix.

30. synchronizer according to claim 29 is characterized in that, described predetermined count value is 32.

31. synchronizer according to claim 27 is characterized in that, described mark frequency multiplication is described largest loop prefix correlation to be done the phase value of the largest loop prefix correlation that arctangent cp cp operation takes out partially.

32., it is characterized in that it is that the inphase/quadrature phase data be multiply by e that the inphase/quadrature phase data to receiving of described mark frequency multiplication deflection correction module are carried out mark frequency multiplication deflection correction according to claim 25 or 26 described synchronizers ^{J θ}, wherein, θ is that the mark frequency multiplication of the inclined to one side estimation module gained of mark frequency multiplication is inclined to one side.

33. according to claim 25 or 26 described synchronizers, it is characterized in that, described integer frequency offset is estimated and the dateout of the fast fourier transform of the inphase/quadrature phase data of timing slip estimation module after acquisition phase is to correct according to signal to noise ratio and mark frequency multiplication deflection correction module is estimated integer frequency offset and timing slip, and the logical design scheme of described integer frequency offset estimation and timing slip estimation module is as described below:

(3-2) set count value k and equal 1;

(3-3) the fast fourier transform dateout is moved clockwise carry out contrary quick Fourier transformation computation behind the k position and the contrary all dateout calculating energies of fast fourier transform, the maximum of energy wherein is designated as k maximum energy value, the fast fourier transform output valve moved counterclockwise carry out contrary quick Fourier transformation computation behind the k position and, the maximum of energy wherein is designated as the-k maximum energy value the contrary all dateout calculating energies of fast fourier transform;

(3-5) count value k equals k and adds 1, is back to step (3-3);

(3-6) compare each energy maximum, find out the peaked maximum of all energy and judge that whether it is greater than the signal energy summation of step (3-1) gained and the product of SNR/ (1+SNR), wherein, SNR is a signal to noise ratio, if then carry out step (3-7), if not, then be back to acquisition phase;

34. synchronizer according to claim 33 is characterized in that, the span of described predetermined shift value is 0 to 128.

35. synchronizer according to claim 34 is characterized in that, described predetermined shift value is 64.

36. according to claim 25 or 26 described synchronizers, it is characterized in that, described frequency deviation adjusting module acquisition phase be calculate gained according to the inclined to one side estimation module of mark frequency multiplication the mark frequency multiplication partially and integer frequency offset is estimated and the intermediate frequency value of the digital controlled oscillator of the integer frequency offset adjustment Digital Down Converter Module of timing slip estimation module calculating gained, wherein, the intermediate frequency value before adjusted intermediate frequency value equals to adjust adds the product of integer frequency offset and inclined to one side sum of mark frequency multiplication and frequency interval.

37. according to claim 25 or 26 described synchronizers, it is characterized in that described frequency deviation adjusting module is to carry out in the intermediate frequency value that the digital controlled oscillator of integer frequency offset and mark frequency multiplication being sent into partially Digital Down Convert of acquisition phase removes to adjust digital controlled oscillator when receiving the null symbol of data transmission frames.

38. according to claim 25 or 26 described synchronizers, it is characterized in that the estimating and the dateout of the fast fourier transform of the timing slip correction inphase/quadrature phase data of timing slip estimation module gained is meant that it is the phase place that step value increases that dateout with fast fourier transform multiply by with the timing slip of described time migration correcting module according to integer frequency offset.

39. synchronizer according to claim 25 is characterized in that, when described tracking phase is meant each data transmission frames after receiving the first frame data transmission frame.

40. according to claim 25 or 39 described synchronizers, it is characterized in that, the inclined to one side estimation module of described mark frequency multiplication is inclined to one side according to the inphase/quadrature phase data estimation mark frequency multiplication of the Cyclic Prefix of phase reference symbol and data symbol at tracking phase, and the logical design scheme of the inclined to one side estimation module of described mark frequency multiplication is as described below:

(6-1) clear 0 to counter A, set count value m and equal 0;

(6-3) judge count value m whether greater than the length of Cyclic Prefix, if, then be back to acquisition phase, if not, then carry out step (6-4);

(6-4) count value m equals m and adds 1, is back to step (6-2);

(6-5) m Cyclic Prefix correlation is made as largest loop prefix correlation;

41. according to the described synchronizer of claim 40, it is characterized in that, the account form of described m Cyclic Prefix correlation is as described below: get previous sign-off position and add M inphase/quadrature phase data behind the m position and previous sign-off position and add (M+L) behind m position M inphase/quadrature phase data after individual, and (M+L) M inphase/quadrature phase data after individual are got conjugation, each inphase/quadrature phase data after the conjugation take advantage of M inphase/quadrature phase data of corresponding beginning to add up then, wherein, M is the length of Cyclic Prefix, and L is the length of valid data.

42., it is characterized in that described predetermined count value is smaller or equal to the length of Cyclic Prefix according to the described synchronizer of claim 40.

43., it is characterized in that described predetermined count value is 32 according to the described synchronizer of claim 42.

44., it is characterized in that described mark frequency multiplication is described largest loop prefix correlation to be done the phase value of the largest loop prefix correlation that arctangent cp cp operation takes out partially according to the described synchronizer of claim 40.

45. according to claim 25 or 39 described synchronizers, it is characterized in that, described integer frequency offset is estimated and the timing slip estimation module is to estimate integer frequency offset and timing slip according to the dateout of the quick Fourier transformation computation of signal to noise ratio and inphase/quadrature phase data at tracking phase, and the logical design scheme of described integer frequency offset estimation and timing slip estimation module is as described below:

(7-3) outgoing position with the pairing contrary fast fourier transform of described energy maximum is decided to be timing slip, finishes the course of work of integer frequency offset estimation and timing slip estimation module;

46. according to claim 25 or 39 described synchronizers, it is characterized in that, described frequency deviation adjusting module is a intermediate frequency value according to the digital controlled oscillator of the mark frequency multiplication offset integer word down conversion module of the inclined to one side estimation module gained of mark frequency multiplication at tracking phase, wherein, the intermediate frequency value before adjusted intermediate frequency value equals to adjust adds that the mark frequency multiplication partially and the product of frequency interval.

47. according to claim 25 or 39 described synchronizers, it is characterized in that described frequency deviation adjusting module is to carry out in the intermediate frequency value that the digital controlled oscillator of the mark frequency multiplication being sent into partially Digital Down Convert of tracking phase removes to adjust digital controlled oscillator when receiving the null symbol of data transmission frames.

48. according to claim 25 or 39 described synchronizers, it is characterized in that the estimating and the dateout of the fast fourier transform of the timing slip correction inphase/quadrature phase data of timing slip estimation module gained is meant that it is the phase place that step value increases that dateout with fast fourier transform multiply by with the timing slip of described time migration correcting module according to integer frequency offset.

49. a method for synchronous that is used for digital audio broadcast receiver is characterized in that described method comprises the steps:

50., it is characterized in that the inclined to one side step (1) of inphase/quadrature phase data estimation mark frequency multiplication of described Cyclic Prefix according to phase reference symbol comprises the steps: according to the described method for synchronous of claim 49

(1-1) clear 0 to counter A, set count value m and equal 0;

(1-4) count value m equals m and adds 1, is back to step (1-2);

(1-5) m Cyclic Prefix correlation is made as largest loop prefix correlation;

51. according to the described method for synchronous of claim 50, it is characterized in that, the account form of described m Cyclic Prefix correlation is as described below: get the null symbol end position and add M inphase/quadrature phase data behind the m position and null symbol end position and add (M+L) behind m position M inphase/quadrature phase data after individual, and (M+L) M inphase/quadrature phase data after individual are got conjugation, each inphase/quadrature phase data after the conjugation take advantage of M inphase/quadrature phase data of corresponding beginning to add up then, wherein, M is the length of Cyclic Prefix, and L is the length of valid data.

52., it is characterized in that described predetermined count value is smaller or equal to the length of Cyclic Prefix according to the described method for synchronous of claim 50.

53., it is characterized in that described predetermined count value is 32 according to the described method for synchronous of claim 52.

54., it is characterized in that described mark frequency multiplication is described largest loop prefix correlation to be done the phase value of the largest loop prefix correlation that arctangent cp cp operation takes out partially according to the described method for synchronous of claim 50.

55., it is characterized in that the described step (2) that the inphase/quadrature phase data that receive are carried out mark frequency multiplication deflection correction is that the inphase/quadrature phase data be multiply by e according to the described method for synchronous of claim 49 ^{J θ}, wherein, θ is that the mark frequency multiplication of step (1) gained is inclined to one side.

56., it is characterized in that described dateout according to signal to noise ratio and quick Fourier transformation computation estimates that the step (3) of integer frequency offset and timing slip comprises the steps: according to the described method for synchronous of claim 49

(3-2) set count value k and equal 1;

(3-5) count value k equals k and adds 1, is back to step (3-3);

57., it is characterized in that the span of described predetermined shift value is 0 to 128 according to the described method for synchronous of claim 56.

58., it is characterized in that described predetermined shift value is 64 according to the described method for synchronous of claim 57.

59. according to the described method for synchronous of claim 49, it is characterized in that the intermediate frequency value that the digital controlled oscillator of integer frequency offset and mark frequency multiplication being sent into partially Digital Down Convert of described step (4) removes to adjust digital controlled oscillator is meant that the intermediate frequency value before adjusted intermediate frequency value equals to adjust adds the product of integer frequency offset and inclined to one side sum of mark frequency multiplication and frequency interval.

60. according to the described method for synchronous of claim 49, it is characterized in that the intermediate frequency value that the digital controlled oscillator of integer frequency offset and mark frequency multiplication being sent into partially Digital Down Convert of described step (4) removes to adjust digital controlled oscillator is to carry out when receiving the null symbol of data transmission frames.

61. according to the described method for synchronous of claim 49, it is characterized in that according to timing slip the dateout of the fast fourier transform of the inphase/quadrature phase data that receive being done the time migration correction and be meant that it is the phase place that step value increases that dateout with fast fourier transform multiply by with the timing slip of described step (5).

62., it is characterized in that described method is used for carrying out described step (1) to (5) when receiving each data transmission frames according to the described method for synchronous of claim 49.

63. a synchronizer that is used for digital audio broadcast receiver is characterized in that, described device comprises:

The inclined to one side estimation module of mark frequency multiplication is used for according to the inphase/quadrature phase data estimation mark frequency multiplication of the Cyclic Prefix of phase reference symbol inclined to one side;

Control module is used to control the inclined to one side estimation module of mark frequency multiplication, mark frequency multiplication deflection correction module, integer frequency offset estimation and timing slip estimation module, frequency deviation adjusting module and the work of time migration correcting module.

64., it is characterized in that the logical design scheme of the inclined to one side estimation module of described mark frequency multiplication is as described below according to the described synchronizer of claim 63:

(1-1) clear 0 to counter A, set count value m and equal 0;

(1-3) judge count value m whether greater than the length of Cyclic Prefix, if, then be back to step (1-1), if not, then carry out step (1-4);

(1-4) count value m equals m and adds 1, is back to step (1-2);

(1-5) m Cyclic Prefix correlation is made as largest loop prefix correlation;

65. according to the described synchronizer of claim 64, it is characterized in that, the account form of described m Cyclic Prefix correlation is as described below: get the null symbol end position and add M inphase/quadrature phase data behind the m position and null symbol end position and add (M+L) behind m position M inphase/quadrature phase data after individual, and (M+L) M inphase/quadrature phase data after individual are got conjugation, each inphase/quadrature phase data after the conjugation take advantage of M inphase/quadrature phase data of corresponding beginning to add up then, wherein, M is the length of Cyclic Prefix, and L is the length of valid data.

66., it is characterized in that described predetermined count value is smaller or equal to the length of Cyclic Prefix according to the described synchronizer of claim 64.

67., it is characterized in that described predetermined count value is 32 according to the described synchronizer of claim 66.

68., it is characterized in that described mark frequency multiplication is described largest loop prefix correlation to be done the phase value of the largest loop prefix correlation that arctangent cp cp operation takes out partially according to the described synchronizer of claim 64.

69., it is characterized in that it is that the inphase/quadrature phase data be multiply by e that the inphase/quadrature phase data to receiving of described mark frequency multiplication deflection correction module are carried out mark frequency multiplication deflection correction according to the described synchronizer of claim 63 ^{J θ}, wherein, θ is that the mark frequency multiplication of the inclined to one side estimation module gained of mark frequency multiplication is inclined to one side.

70., it is characterized in that the logical design scheme of described integer frequency offset estimation and timing slip estimation module is as described below according to the described synchronizer of claim 63:

(3-2) set count value k and equal 1;

(3-5) count value k equals k and adds 1, is back to step (3-3);

(3-6) compare each energy maximum, find out the peaked maximum of all energy and judge that whether it is greater than the signal energy summation of step (3-1) gained and the product of SNR/ (1+SNR), wherein, SNR is a signal to noise ratio, if, then carry out step (3-7), if not, then rework by the inclined to one side estimation module of control module control mark frequency multiplication;

71., it is characterized in that the span of described predetermined shift value is 0 to 128 according to the described synchronizer of claim 70.

72., it is characterized in that described predetermined shift value is 64 according to the described synchronizer of claim 71.

73. according to the described synchronizer of claim 63, it is characterized in that the mark frequency multiplication according to the inclined to one side estimation module calculating of mark frequency multiplication gained of described frequency deviation adjusting module is inclined to one side and integer frequency offset is estimated and the intermediate frequency value of the digital controlled oscillator of the integer frequency offset adjustment Digital Down Converter Module of timing slip estimation module calculating gained is meant that adjusted intermediate frequency value equals to adjust the product that preceding intermediate frequency value adds integer frequency offset and inclined to one side sum of mark frequency multiplication and frequency interval.

74. according to the described synchronizer of claim 63, it is characterized in that described frequency deviation adjusting module is to carry out in the intermediate frequency value that the digital controlled oscillator of integer frequency offset and mark frequency multiplication being sent into partially Digital Down Convert of acquisition phase removes to adjust digital controlled oscillator when receiving the null symbol of data transmission frames.

75. according to the described synchronizer of claim 63, it is characterized in that the estimating and the dateout of the fast fourier transform of the timing slip correction inphase/quadrature phase data of timing slip estimation module gained is meant that it is the phase place that step value increases that dateout with fast fourier transform multiply by with the timing slip of described time migration correcting module according to integer frequency offset.

76. according to the described synchronizer of claim 63, it is characterized in that described control module is used for the inclined to one side estimation module of control mark frequency multiplication, mark frequency multiplication deflection correction module, integer frequency offset estimation and timing slip estimation module, frequency deviation adjusting module and the work of time migration correcting module when receiving each data transmission frames.