CN101754352B - Method and device for estimating time bias in synchronous process of LTE system - Google Patents

Abstract

The invention relates to a method and a device for estimating a time bias in the synchronous process of an LTE system. The method comprises the following steps: receiving a subcarrier which is outputted after being captured primarily synchronously and comprises a main synchronous signal, and utilizing the subcarrier to estimate an interference value of an adjacent cell; and estimating the time bias of the cell after eliminating the interference value of the adjacent cell from an estimation item of the cell. Therefore, the method and the device of the invention can eliminate the strong interference of the synchronous signal of the adjacent cell, improve the estimation performance of the time bias and reduce the algorithm realization link, and at the same time as the process of eliminating the interference and the noise is added and the LPF and accumulation processes are removed in the process of estimating the time bias, the method and the device can make the time bias estimation closer to the expected synchronous sampling point position to effectively improve the precision of the time bias estimation.

Description

The method and apparatus of estimating time bias in a kind of LTE system synchronization process

Technical field

The present invention relates to communication technical field, relate in particular to the method and apparatus of estimating time bias in a kind of LTE system synchronization process.

Background technology

At present, along with the continuous development of the communication technology, LTE (Long Term Evolution, Long Term Evolution) simultaneous techniques mainly depends on master sync signal and realizes; And according to the regulation of existing protocol, master sync signal can be expressed as:

$d_u\left(n\right)=\left\{\begin{array}{cc}{e}^{-j\frac{\mathrm{\πun}(n+1)}{63}}& n=\mathrm{0,1},...,30\\ e^{-j\frac{\mathrm{\πu}(n+1)(n+2)}{63}}& n=\mathrm{31,32},...,61\end{array}\right.$

According to the different cell sectors number different root sequence u of definition, can confirm the master sync signal that system is current; Wherein, u gets 25,29 and 34 3 values respectively.Yet; When user side is followed the tracks of synchronously; If user side is in cell edge; Interference will be caused at the modulation signal of launching different u value sequences with synchronization frequently in then contiguous sub-district, though master sync signal itself owing to adopt the sequence of different u values can suppress interference signal, said interference signal still can produce the influence of can not ignore for the frequency offset estimating of estimation of frame clock synchronization and system; And with respect to the interference that Gaussian noise causes, the interference of said adjacent sub-district has more parasitic character.Must consider how to eliminate adjacent cell when therefore, synchronously the time, estimating partially disturbs.

To this problem, the solution that exists in the prior art is: estimate the deviation of time at frequency domain, and inclined to one side error when revising through the mode of revising synchronous sliding window, and eliminate the interference that time deviation is brought demodulation; Time inclined to one side estimation procedure as shown in Figure 1, the indication of switch among the figure be the time two processes estimating partially, i.e. synchronization acquistion just with the time two processes of tracking partially: concrete, system as shown in Figure 1 generally adopts the feedback network mode; In the first synchronization acquistion stage, pass through the initial position that first synchronization acquistion unit obtains synchronization frame for the master sync signal that receives, after catching generation; Confirm initial sync bit; Adjustment System FFT (Fast Fourier Transform, fast Fourier transform) window is in CP (Cyclic Prefix, Cyclic Prefix) scope; The subcarrier that will contain master sync signal then sends to offset estimator when meticulous, system's incision clock tracing stage; In the clock tracing stage, offset estimator is operated in frequency domain when meticulous, calculates the deviation that estimates the system-frame clock through the subcarrier to master sync signal, estimate this moment the time partially in the CP of system scope; Wherein, said when meticulous the computational process of offset estimator following:

The sub-carrier signal of the master sync signal that receives, i.e. signal Y on the primary synchronization channel pilot frequency locations _KCan be expressed as: Y _K=H _{1, K}* X _{1, K}* e ^{-j2 π K α/N}+ H _{2, K}* X _{2, K}* e ^{-j2 π K β/N}+ n _k(2-1)

Wherein, X _{1, K}Be the synchronous pilot channel of expectation of transmitting terminal emission, X _{2, K}Be the synchronous interference signal from adjacent cell, X _{1, K}And X _{2, K}Signal is the CAZAC sequence of different u roots, α be master sync signal the time inclined to one side, β be the synchronous interference signal the time inclined to one side, H _{1, K}Be the response of master sync signal channel transmitted, H _{2, K}Be the channel response of interference signal, n _kIt is white Gaussian noise; Hence one can see that,

Q _K＝Y _K×X _1，K ^*＝H _1，K×|X _1，K|×e ^-j2πKα/N+H _2，K×e ^-j2πKβ/N×X _2，K×X _1，K ^*+n _k (2-2)

Wherein second and the 3rd is all noise item; Therefore, Q _K=H _{1, K}* | X _{1, K}| * e ^{-j2 π K α/N}+ η _K, then, R _K=Q _K* Q _K+1 ^*, utilize maximum-likelihood criterion can estimate the time deviation of being asked again

Promptly $\widehat{\mathrm{\α}}=(1/2\mathrm{\π})\×N\×\mathrm{Arg}\mathrm{Max}\left({\hat{R}}_K\right).$

Obviously in this scheme, distracter is the same with noise item all to be to remove through likelihood estimation and loop low pass filter (LPF) and accumulation as shown in Figure 1; But distracter is not proper noise; The coloured noise characteristic that it demonstrates is bigger for estimation effect; Simultaneously because the loop LPF is a kind of feedback accumulation mode; Therefore it can produce certain estimation and lags behind, this just make easily last estimation the time have certain hysteresis partially, can't obtain to estimate partially when accurate.

Summary of the invention

In view of this, the invention provides the method and apparatus of estimating time bias in a kind of LTE system synchronization process, can eliminate the strong jamming of adjacent cell synchronizing signal, the precision of estimating partially when effectively improving.

For addressing the above problem, technical scheme provided by the invention is following:

The method of estimating time bias in a kind of LTE system synchronization process, this method comprises:

Receive the subcarrier of exporting after the synchronization acquistion just that contains master sync signal, utilize this subcarrier to estimate the interference value of adjacent cell;

From this sub-district estimation item, estimate the time deviation of this sub-district behind the interference value of removal adjacent cell;

Wherein: the interference value of estimating adjacent cell is specifically realized according to following mode: through the conjugate multiplication that master sync signal and the said subcarrier that comprises master sync signal with adjacent cell carry out pointwise, obtain the estimation item that adjacent cell disturbs; The estimation item that the adjacent cell that obtains is disturbed carries out denoising; Estimation item through the adjacent cell after the denoising is disturbed carries out the interference value that discrete Fourier transform obtains adjacent cell;

Removing the interference value of adjacent cell specifically realizes according to following mode: through this sub-district master sync signal and the said subcarrier that contains master sync signal are carried out the pointwise conjugate multiplication, obtain the estimation item of this sub-district; Interference value and this sub-district master sync signal of adjacent cell are carried out the computing of pointwise conjugate multiplication; After again operation result and the pointwise of adjacent cell master sync signal being multiplied each other, through deducting the interference value that result after said pointwise is multiplied each other removes adjacent cell estimating from this sub-district;

The time deviation that estimates this sub-district specifically realizes according to following mode: the estimation item after this sub-district is gone to disturb carries out denoising; Carry out the conjugate multiplication computing of discrete Fourier transform and pointwise after the denoising earlier; Operation result is estimated this sub-district time deviation through maximum-likelihood criterion.

The device of estimating time bias in a kind of LTE system synchronization process, this device comprises: interference estimator offset estimator when going to disturb; Wherein,

Said interference estimator is used to receive the subcarrier of exporting after the synchronization acquistion just that contains master sync signal, and utilizes this subcarrier to estimate the interference value of adjacent cell;

Said when going to disturb offset estimator be used to receive the interference value of the adjacent cell of said interference estimator output, and from this sub-district is estimated, remove the time deviation that estimates this sub-district behind the interference value of adjacent cell;

Said interference estimator comprises: first arithmetic device, first denoising unit and the second arithmetic device; Said first arithmetic device is used for the conjugate multiplication of carrying out pointwise through master sync signal and the said subcarrier that comprises master sync signal with adjacent cell, obtains the estimation item that adjacent cell disturbs; The estimation item that the adjacent cell that the said first denoising unit is used for that said first arithmetic device is obtained disturbs carries out denoising; Said second arithmetic device is used for the estimation item that the adjacent cell after the said first denoising unit denoising disturbs is carried out the interference value that discrete Fourier transform obtains adjacent cell;

Said when going to disturb offset estimator comprise: the 3rd arithmetic unit with remove the unit, said the 3rd arithmetic unit is used for obtaining the estimation item of this sub-district through this sub-district master sync signal and the said subcarrier that contains master sync signal are carried out the pointwise conjugate multiplication; Said removal unit is used for the interference value of adjacent cell and this sub-district master sync signal are carried out the computing of pointwise conjugate multiplication; After again operation result and the pointwise of adjacent cell master sync signal being multiplied each other, deduct the interference value that result after said pointwise is multiplied each other removes adjacent cell estimating through this sub-district that obtains from said the 3rd arithmetic unit;

Said when going to disturb offset estimator also comprise: the estimation item after the second denoising unit, the 4th arithmetic unit and estimator, the said second denoising unit are used for this sub-district gone to disturb carries out denoising; Said the 4th arithmetic unit is used for a conjugate multiplication computing of successively carrying out discrete Fourier transform and pointwise is estimated in this sub-district after the said second denoising unit denoising; The operation result that said estimator is used to utilize said the 4th arithmetic unit to obtain estimates this sub-district time deviation through maximum-likelihood criterion.

Can find out, adopt the inventive method and device, in LTE system timing tracing process; At first estimate the interference value of adjacent cell; Remove this distracter and noise earlier before when carrying out, estimating partially then, utilize maximum-likelihood criterion to estimate time deviation again, can eliminate the strong jamming of adjacent cell synchronizing signal with this; Inclined to one side estimated performance when having improved has reduced the algorithm realization link; Simultaneously and since the time inclined to one side estimation procedure in, added to go to disturb and removed LPF and accumulation with the process of noise, estimate more synchronous sampling point position in the time of can making partially, the precision of estimating partially when effectively raising near expectation.

Description of drawings

In order to be illustrated more clearly in the embodiment of the invention or technical scheme of the prior art; To do to introduce simply to the accompanying drawing of required use in embodiment or the description of the Prior Art below; Obviously, the accompanying drawing in describing below only is some embodiments of the present invention, for those of ordinary skills; Under the prerequisite of not paying creative work property, can also obtain other accompanying drawing according to these accompanying drawings.

Fig. 1 is existing traditional time inclined to one side estimation procedure sketch map;

Fig. 2 is the method flow sketch map of the embodiment of the invention 1;

Fig. 3 is that the device of the embodiment of the invention 2 is formed structural representation;

Fig. 4 is that another device of the embodiment of the invention 2 is formed structural representation;

Fig. 5 is that the system of the embodiment of the invention forms structural representation.

Embodiment

Basic thought of the present invention is in LTE system timing tracing process; Subcarrier to the master sync signal after the first synchronization acquistion is at first carried out Interference Estimation; Removing distracter and noise earlier before when carrying out, estimating partially then utilizes maximum-likelihood criterion to estimate time deviation again; Can eliminate the strong jamming of adjacent cell synchronizing signal with this, inclined to one side estimated performance when having improved has reduced the algorithm realization link; Simultaneously and since the time inclined to one side estimation procedure in, added to go to disturb and removed LPF and accumulation with the process of noise, estimate more synchronous sampling point position in the time of can making partially, the precision of estimating partially when effectively raising near expectation.

To combine the accompanying drawing in the embodiment of the invention below, the technical scheme in the embodiment of the invention will be carried out clear, intactly description; Obviously, described embodiment only is the present invention's part embodiment, rather than whole embodiment.Based on the embodiment among the present invention, those of ordinary skills are not making the every other embodiment that is obtained under the creative work prerequisite, all belong to the scope of the present invention's protection.

The embodiment of the invention 1 provides the method for estimating time bias in a kind of LTE system synchronization process, and as shown in Figure 2, this method comprises:

Interference estimation step 210: receive the subcarrier of exporting after the synchronization acquistion just that contains master sync signal, utilize this subcarrier to estimate the interference value of adjacent cell;

The first synchronization acquistion process that present embodiment is mentioned is similar with existing traditional first synchronization acquistion process: will be sampled through ADC (analog to digital converter) by the baseband signal that antenna port receives; After obtaining the OFDM mark signal of reception; The fetched of the OFDM symbol at the master sync signal place that 5ms estimates before utilizing contains the OFDM symbol of master sync signal; After removing cyclic prefix CP, it is carried out the FFT transform operation, extract the subcarrier Y that contains master sync signal _KInput signal as the Interference Estimation operation; Concrete, present embodiment proposes to estimate the interference value of adjacent cell in the following manner, but is not limited thereto:

S211: with the master sync signal X of the adjacent cell of this locality storage _{2, K}With the conjugate multiplication that the said subcarrier that comprises master sync signal carries out pointwise, obtain the estimation item C of adjacent cell interference signal _k=Y _{1, K}* X _{2, K} ^*

S212: the estimation item C that the adjacent cell that obtains is disturbed _kCarry out denoising: through to C _kIDFT (Inverse Discrete Fourier Transform) computing of carrying out at 64 is transformed into time domain with it, i.e. W _K=IDFT (C _K); For the W that obtains after the said conversion _K(k=1,2 ... 64) keep preceding 5 points, with remaining W _KPoint is put 0 denoising, promptly To remove the influence of noise to estimated result;

S213: then to after the denoising

Carry out 64 DFT (discrete Fourier transform) conversion it is transformed into frequency domain, can obtain the interference value of adjacent cell

Wherein, X _{2, K}Interference signal for adjacent cell.

Inclined to one side estimating step 220 when going to disturb: the time deviation that from the estimation item of this sub-district, estimates this sub-district behind the interference value of removal adjacent cell.

Concrete, present embodiment proposes to remove the interference value of adjacent cell in the following manner, but is not limited thereto:

S221: with this sub-district master sync signal X of this locality storage _{1, K}With the subcarrier Y that contains master sync signal that exports after the said synchronization acquistion just _KCarry out the conjugate multiplication of pointwise, obtain the estimation item Q of this sub-district _K, wherein a Q is estimated in this sub-district _KBe inclined to one side estimated value Q when containing distracter and noise pending _K, also be Q _K=Y _K* X _{1, K} ^*=H _{1, K}* | X _{1, K}| * e ^{-j2 π K α/N}+ H _{2, K}* e ^{-j2 π K β/N}* X _{2, K}* X _{1, K} ^*+ n _k

S222: to the interference value of adjacent cell

This sub-district master sync signal X with this locality storage _{1, K}Carry out the computing of pointwise conjugate multiplication, promptly

Result after will taking advantage of then and the local adjacent cell master sync signal X that stores _{2, K}Pointwise is multiplied each other

Estimate to deduct the result after multiplying each other the item from this sub-district again, obtain this sub-district and remove the estimation item after disturbing

Promptly ${\stackrel{\&OverBar;}{Q}}_K=Y_K\&times;{{\mathrm{<figure-callout\; id="1"\; label="X"\; filenames="H200910243833XE00022.png,H200910243833XE00031.png"\; state="\{\{state\}\}">X</figure-callout>}}_{1,K}}^{*}-{\hat{H}}_{2,K}\&times;e^{-j2\mathrm{\&pi;\; K}\widehat{\mathrm{\&beta;}}/N}\&times;X_{2,K}\&times;{{\mathrm{<figure-callout\; id="1"\; label="X"\; filenames="H200910243833XE00022.png,H200910243833XE00031.png"\; state="\{\{state\}\}">X</figure-callout>}}_{1,K}}^{*}={\mathrm{<figure-callout\; id="1"\; label="H"\; filenames="H200910243833XE00022.png,H200910243833XE00031.png"\; state="\{\{state\}\}">H</figure-callout>}}_{1,K}\&times;\left|{\mathrm{<figure-callout\; id="1"\; label="X"\; filenames="H200910243833XE00022.png,H200910243833XE00031.png"\; state="\{\{state\}\}">X</figure-callout>}}_{1,K}\right|\&times;e^{-j2\mathrm{\&pi;\; K\&alpha;}/N}+n_k.$

Simultaneously, present embodiment has also proposed to estimate the time deviation of this sub-district in the following manner, but is not limited thereto:

S223: the estimation item after this sub-district that obtains gone to disturb

Carry out denoising: through right

IDFT (anti-inverse discrete Fourier transform) computing of carrying out at 64 is transformed into time domain with it, promptly

For the V that obtains after the said conversion _K(k=1,2 ... 64) keep preceding 5 points, with remaining V _KPoint is put 0 denoising, promptly

To remove the influence of noise to estimated result;

S224: then

after the denoising carried out 64 DFT (discrete Fourier transform) conversion it is transformed into frequency domain, the result

i.e. after promptly conjugate multiplication of again the front and back point among the result after the conversion

being carried out pointwise obtains multiplying each other is

S225: to what obtain

Utilize maximum-likelihood criterion to estimate to estimate this sub-district time deviation

Promptly $\widehat{\mathrm{\&alpha;}}=(1/2\mathrm{\&pi;})\&times;N\&times;\mathrm{Arg}\mathrm{Max}\left({\stackrel{\widehat{\&OverBar;}}{R}}_K\right).$

In addition, in order in cell search process, better to realize the switching of minizone, as shown in Figure 3, the embodiment of the invention proposes on the basis of each step of method of estimating time bias in above-mentioned LTE system synchronization process, and this method also can comprise:

Step 230: obtain the interference value of said adjacent cell, utilize the interference value of said adjacent cell to estimate the time deviation of adjacent cell;

Concrete, can realize through following manner, but be not limited thereto:

S231: to the conjugate multiplication that the point of the front and back in the interference value of said adjacent cell carries out pointwise, the result after obtaining multiplying each other

Promptly ${\hat{R}}_2={\hat{H}}_{2,K}\&times;e^{-j2\mathrm{\&pi;}\widehat{\mathrm{\&beta;}}K/N}\&times;{\hat{H}}_{2,K+1}\&times;e^{-j2\mathrm{\&pi;}\widehat{\mathrm{\&beta;}}K/N}.$

S232: to what obtain

Utilize maximum-likelihood criterion to estimate, obtain the estimated result of adjacent cell time deviation

Promptly $\widehat{\mathrm{\&beta;}}=(1/2\mathrm{\&pi;})\&times;N\&times;\mathrm{Arg}\mathrm{Max}\left({\hat{R}}_{2,K}\right).$

Can find out, adopt the method for the embodiment of the invention, in LTE system timing tracing process; At first estimate the interference value of adjacent cell; Remove this distracter and noise earlier before when carrying out, estimating partially then, utilize maximum-likelihood criterion to estimate time deviation again, can eliminate the strong jamming of adjacent cell synchronizing signal with this; Inclined to one side estimated performance when having improved has reduced the algorithm realization link; Simultaneously and since the time inclined to one side estimation procedure in, added to go to disturb and removed LPF and accumulation with the process of noise, estimate more synchronous sampling point position in the time of can making partially, the precision of estimating partially when effectively raising near expectation.

Based on above-mentioned thought, the embodiment of the invention 2 has also proposed the device of estimating time bias in a kind of LTE system synchronization process, and is as shown in Figure 3, and this device 300 comprises: interference estimator 310 offset estimator 320 when going to disturb; Wherein,

Said interference estimator 310 is used to receive the subcarrier of exporting after the synchronization acquistion just that contains master sync signal, and utilizes this subcarrier to estimate the interference value of adjacent cell;

Said when going to disturb offset estimator 320 be used to receive the interference value of the adjacent cell of said interference estimator 310 outputs, and from this sub-district is estimated, remove the time deviation that estimates this sub-district behind the interference value of adjacent cell.

Wherein, said interference estimator 310 comprises: first arithmetic device, first denoising unit and the second arithmetic device; Said first arithmetic device is used for the master sync signal X with the adjacent cell of this locality storage _{2, K}With the conjugate multiplication that the said subcarrier that comprises master sync signal carries out pointwise, obtain the estimation item C of adjacent cell interference signal _k=Y _{1, K}* X _{2, K} ^*The estimation item C that the adjacent cell that the said first denoising unit is used for that said first arithmetic device is obtained disturbs _kCarry out denoising: concrete, through to C _kThe IDFT computing of carrying out at 64 is transformed into time domain with it, i.e. W _K=IDFT (C _K); For the W that obtains after the said conversion _K(k=1,2 ... 64) keep preceding 5 points, with remaining W _KPoint is put 0 denoising, promptly

To remove the influence of noise to estimated result; Said second arithmetic device is used for through to after the said first denoising unit denoising

Carry out 64 DFT conversion and obtain the interference value of adjacent cell

Wherein, X _{2, K}Interference signal for adjacent cell;

In addition, said when going to disturb offset estimator 320 comprise: the 3rd arithmetic unit with remove the unit; Wherein, said the 3rd arithmetic unit is used for through this sub-district master sync signal X with this locality storage _{1, K}With the subcarrier Y that contains master sync signal that exports after the said synchronization acquistion just _KCarry out the conjugate multiplication of pointwise, obtain the estimation item Q of this sub-district _K, wherein a Q is estimated in this sub-district _KBe inclined to one side estimated value Q when containing distracter and noise pending _K, also be Q _K=Y _K* X _{1, K} ^*=H _{1, K}* | X _{1, K}| * e ^{-j2 π K α/N}+ H _{2, K}* e ^{-j2 π K β/N}* X _{2, K}* X _{1, K} ^*+ n _kSaid removal unit is used for the interference value to adjacent cell

This sub-district master sync signal X with this locality storage _{1, K}Carry out the computing of pointwise conjugate multiplication, again with the adjacent cell master sync signal X of operation result with local storage _{2, K}Pointwise is multiplied each other

After, estimate to deduct the result after said pointwise is multiplied each other the item from this sub-district that said the 3rd arithmetic unit obtains, obtain this sub-district and remove the estimation item after disturbing

Promptly ${\stackrel{\&OverBar;}{Q}}_K=Y_K\&times;{X_{1,K}}^{*}-{\hat{H}}_{2,K}\&times;e^{-j2\mathrm{\&pi;\; K}\widehat{\mathrm{\&beta;}}/N}\&times;X_{2,K}\&times;{X_{1,K}}^{*}=H_{1,K}\&times;\left|X_{1,K}\right|\&times;e^{-j2\mathrm{\&pi;\; K\&alpha;}/N}+n_k.$

In addition, said when going to disturb offset estimator 320 also comprise: the second denoising unit, the 4th arithmetic unit and estimator; Wherein, the estimation item after the said second denoising unit is used for this sub-district gone to disturb Carry out denoising: concrete, through right

The IDFT computing of carrying out at 64 is transformed into time domain with it, promptly

For the V that obtains after the said conversion _K(k=1,2 ... 64) keep preceding 5 points, with remaining V _KPoint is put 0 denoising, promptly To remove the influence of noise to estimated result; Said the 4th arithmetic unit is used for after the said second denoising unit denoising

Carry out 64 DFT conversion, the result after the conjugate multiplication of again the front and back point in the sampling point as a result after the conversion being carried out pointwise obtains multiplying each other

Flow to said estimator; Said estimator is used to utilize said the 4th arithmetic unit to carry

Estimate this sub-district time deviation through maximum-likelihood criterion

It should be noted that; Composition structure based on the foregoing description device; As shown in Figure 4, this device 300 also can comprise: obtain the interference value of said adjacent cell, and utilize the interference value of said adjacent cell to estimate the adjacent cell synchronizing signal monitoring unit 330 of the time deviation of adjacent cell.

Wherein, said adjacent cell synchronizing signal monitoring unit 330 can comprise: the 5th arithmetic unit and adjacent sub-district estimator; Said the 5th arithmetic unit is used to receive the interference value of the adjacent sub-district that said interference estimator sends And the conjugate multiplication that the point of the front and back in the interference value of said adjacent sub-district is carried out pointwise

Said adjacent sub-district estimator is used to the operation result that utilizes said the 5th arithmetic unit to obtain

Estimate the time deviation of adjacent cell through maximum-likelihood criterion $\widehat{\mathrm{\&beta;}}=(1/2\mathrm{\&pi;})\&times;N\&times;\mathrm{Arg}\mathrm{Max}\left({\hat{R}}_{2,K}\right).$

In addition; Those skilled in the art readily understand; In the LTE system synchronization process in the foregoing description the device of estimating time bias in the specific implementation can also as in the LTE system in order to the parts of deviation estimated time; As shown in Figure 5, thereby the LTE system that comprises the estimating time bias device in the foregoing description also should belong to protection scope of the present invention, repeats no more at this.

It will be understood by those skilled in the art that and to use in many different processes and the technology any one to come expression information, message and signal.For example, the message of mentioning in the above-mentioned explanation, information can be expressed as voltage, electric current, electromagnetic wave, magnetic field or magnetic particle, light field or above combination in any.

The professional can also further should be able to recognize; The unit and the algorithm steps of each example of describing in conjunction with embodiment disclosed herein; Can realize with electronic hardware, computer software or the combination of the two; For the interchangeability of hardware and software clearly is described, the composition and the step of each example described prevailingly according to function in above-mentioned explanation.These functions still are that software mode is carried out with hardware actually, depend on the application-specific and the design constraint of technical scheme.The professional and technical personnel can use distinct methods to realize described function to each certain applications, but this realization should not thought and exceeds scope of the present invention.

The method of describing in conjunction with embodiment disclosed herein or the step of algorithm can be directly with the software modules of hardware, processor execution, and perhaps the combination of the two is implemented.Software module can place the storage medium of any other form known in random asccess memory (RAM), internal memory, read-only memory (ROM), electrically programmable ROM, electrically erasable ROM, register, hard disk, moveable magnetic disc, CD-ROM or the technical field.

To the above-mentioned explanation of the disclosed embodiments, make this area professional and technical personnel can realize or use the present invention.Multiple modification to these embodiment will be conspicuous concerning those skilled in the art, and defined General Principle can realize under the situation that does not break away from the spirit or scope of the present invention in other embodiments among this paper.Therefore, the present invention will can not be restricted to these embodiment shown in this paper, but will meet and principle disclosed herein and features of novelty the wideest corresponding to scope.

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

Claims (4)

1. the method for estimating time bias in the LTE system synchronization process is characterized in that this method comprises:

Receive the subcarrier of exporting after the synchronization acquistion just that contains master sync signal, utilize this subcarrier to estimate the interference value of adjacent cell;

From this sub-district estimation item, estimate the time deviation of this sub-district behind the interference value of removal adjacent cell;

Wherein: the interference value of estimating adjacent cell is specifically realized according to following mode: through the conjugate multiplication that master sync signal and the said subcarrier that comprises master sync signal with adjacent cell carry out pointwise, obtain the estimation item that adjacent cell disturbs; The estimation item that the adjacent cell that obtains is disturbed carries out denoising; Estimation item through the adjacent cell after the denoising is disturbed carries out the interference value that discrete Fourier transform obtains adjacent cell;

Removing the interference value of adjacent cell specifically realizes according to following mode: through this sub-district master sync signal and the said subcarrier that contains master sync signal are carried out the pointwise conjugate multiplication, obtain the estimation item of this sub-district; Interference value and this sub-district master sync signal of adjacent cell are carried out the computing of pointwise conjugate multiplication; After again operation result and the pointwise of adjacent cell master sync signal being multiplied each other, through deducting the interference value that result after said pointwise is multiplied each other removes adjacent cell estimating from this sub-district;

The time deviation that estimates this sub-district specifically realizes according to following mode: the estimation item after this sub-district is gone to disturb carries out denoising; Carry out the conjugate multiplication computing of discrete Fourier transform and pointwise after the denoising earlier; Operation result is estimated this sub-district time deviation through maximum-likelihood criterion.

2. method according to claim 1 is characterized in that, this method also comprises: obtain the interference value of said adjacent cell, utilize the interference value of said adjacent cell to estimate the time deviation of adjacent cell.

3. the device of estimating time bias in the LTE system synchronization process is characterized in that this device comprises: interference estimator offset estimator when going to disturb; Wherein,

Said interference estimator is used to receive the subcarrier of exporting after the synchronization acquistion just that contains master sync signal, and utilizes this subcarrier to estimate the interference value of adjacent cell;

Said when going to disturb offset estimator be used to receive the interference value of the adjacent cell of said interference estimator output, and from this sub-district is estimated, remove the time deviation that estimates this sub-district behind the interference value of adjacent cell;

Said interference estimator comprises: first arithmetic device, first denoising unit and the second arithmetic device; Said first arithmetic device is used for the conjugate multiplication of carrying out pointwise through master sync signal and the said subcarrier that comprises master sync signal with adjacent cell, obtains the estimation item that adjacent cell disturbs; The estimation item that the adjacent cell that the said first denoising unit is used for that said first arithmetic device is obtained disturbs carries out denoising; Said second arithmetic device is used for the estimation item that the adjacent cell after the said first denoising unit denoising disturbs is carried out the interference value that discrete Fourier transform obtains adjacent cell;

Said when going to disturb offset estimator comprise: the 3rd arithmetic unit with remove the unit, said the 3rd arithmetic unit is used for obtaining the estimation item of this sub-district through this sub-district master sync signal and the said subcarrier that contains master sync signal are carried out the pointwise conjugate multiplication; Said removal unit is used for the interference value of adjacent cell and this sub-district master sync signal are carried out the computing of pointwise conjugate multiplication; After again operation result and the pointwise of adjacent cell master sync signal being multiplied each other, deduct the interference value that result after said pointwise is multiplied each other removes adjacent cell estimating through this sub-district that obtains from said the 3rd arithmetic unit;

Said when going to disturb offset estimator also comprise: the estimation item after the second denoising unit, the 4th arithmetic unit and estimator, the said second denoising unit are used for this sub-district gone to disturb carries out denoising; Said the 4th arithmetic unit is used for a conjugate multiplication computing of successively carrying out discrete Fourier transform and pointwise is estimated in this sub-district after the said second denoising unit denoising; The operation result that said estimator is used to utilize said the 4th arithmetic unit to obtain estimates this sub-district time deviation through maximum-likelihood criterion.

4. device according to claim 3 is characterized in that, this device also comprises: obtain the interference value of said adjacent cell, and utilize the interference value of said adjacent cell to estimate the adjacent cell synchronizing signal monitoring unit of the time deviation of adjacent cell.

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