CN101026607A - Common frequency community downlink synchronous code detecting method and device - Google Patents

Abstract

The method includes steps: (1) based on basic SYNC-DL code to generate applied SYNC-DL code with length being equal to length of actual received SYNC-DL code; (2) carrying out Fourier transform for actual received SYNC-DL code and each group of applied SYNC-DL code so as to obtain corresponding frequency domain sequence (FDS); (3) based on FDS of actual received SYNC-DL code and FDS of applied SYNC-DL code, using mode of serial interference cancellation obtains active SYNC-DL code set. Through Fourier transform, and mode of serial interference cancellation, the invention processes received SYNC-DL code so as to detect information of SYNC-DL code of each cofrequency sectors precisely. The invention reduces same frequency interference effectively.

Description

A kind of detection method of common frequency community downlink synchronous code and device

Technical field

The invention belongs to wireless communication technology field, specifically, relate to the detection method and the device of common frequency community downlink synchronous code in a kind of TD SDMA (TD-SCDMA) system.

Background technology

Along with development of wireless communication devices and 3G (Third Generation) Moblie (3G) rise in the world, Radio Resource becomes more and more nervous as a kind of Limited resources.For the TD-SCDMA system of one of 3G mainstream standard, its Radio Resource that is assigned with also is very limited.In order to improve the availability of frequency spectrum of TD-SCDMA system, identical networking becomes a kind of effective solution.But identical networking has also brought co-channel interference when improving the availability of frequency spectrum.

Co-channel interference is meant the different districts inter-user interference that contiguous co-frequency cell causes because of using same carrier frequencies to carry out transfer of data.Co-channel interference can be brought influence to communication system in many-side, mainly shows: access, measurement, power control and aspects such as power system capacity and communication quality.Improve system with the performance under the situation frequently, an important condition is exactly the information that obtains adjacent co-frequency cell, down-going synchronous (SYNC-DL) sign indicating number information for example, and these information fully are applied in the middle of the input of receiver, to reduce co-channel interference.

In the TD-SCDMA system, have 32 groups of SYNC-DL sign indicating numbers, neighbor cell uses different SYNC-DL sign indicating numbers.The SYNC-DL sign indicating number is sent by the base station, and user terminal (UE) is set up down-going synchronous according to the SYNC-DL sign indicating number that receives, and finishes the necessary links of communication such as frequency deviation adjustment.

Usually, the SYNC-DL sign indicating number detects and finishes at access procedure.In access procedure, UE at first determines the position of SYNC-DL sign indicating number according to the frame structure features of TD-SCDMA system, then the SYNC-DL sign indicating number that receives is discerned, and calculates its channel estimating, and then finishes important steps such as synchronous adjustment, frequency deviation adjustment.But under with the frequency situation, the SYNC-DL sign indicating number that receives is the signal that the SYNC-DL sign indicating number of a plurality of adjacent co-frequency cells is superimposed, and this brings certain difficulty for detection of SYNC-DL sign indicating number.

As seen, when improving the availability of frequency spectrum, how to carry out the SYNC-DL sign indicating number exactly and detect, thereby reduce co-channel interference effectively, just become the technical problem that needs to be resolved hurrily by identical networking.

Summary of the invention

Technical problem to be solved by this invention provides a kind of detection method and device of common frequency community downlink synchronous code, obtaining SYNC-DL sign indicating number testing result accurately, thereby reduces co-channel interference effectively.

For addressing the above problem, it is as follows to the invention provides scheme:

A kind of detection method of common frequency community downlink synchronous code may further comprise the steps:

(A) according to basic SYNC-DL sign indicating number, generating length is the practical SYNC-DL sign indicating number of actual reception SYNC-DL code length;

(B) respectively actual reception SYNC-DL sign indicating number and each are organized practical SYNC-DL sign indicating number and carry out Fourier transform, obtain corresponding frequency domain sequence;

(C) according to actual reception SYNC-DL sign indicating number frequency domain sequence and practical SYNC-DL sign indicating number frequency domain sequence, the SYNC-DL sign indicating number collection that the mode by counteracting serial interference obtains activating.

Preferably, in the step (A), basic SYNC-DL sign indicating number is handled, thereby generated practical SYNC-DL sign indicating number by the mode of up-sampling and/or zero padding.

Preferably, step (C) specifically comprises step:

(C1), calculate the channel estimating of respectively organizing the SYNC-DL sign indicating number respectively according to actual reception SYNC-DL sign indicating number frequency domain sequence and practical SYNC-DL sign indicating number frequency domain sequence;

(C2), select one group of the strongest SYNC-DL sign indicating number of signal according to channel estimation results;

(C3) judge whether the strongest SYNC-DL sign indicating number of described signal satisfies activation condition, if, then with execution in step (C4) behind the SYNC-DL sign indicating number collection of its adding activation, otherwise, the detection of end flow process;

(C4) the strongest SYNC-DL sign indicating number composition of signal in the actual reception SYNC-DL sign indicating number frequency domain sequence is carried out Interference Cancellation, the actual reception SYNC-DL sign indicating number frequency domain sequence that obtains upgrading, and to the remaining operation of respectively organizing SYNC-DL sign indicating number continuation execution from step (C1) beginning.

Preferably, step (C1) specifically comprises:

Successively actual reception SYNC-DL sign indicating number frequency domain sequence and each are organized practical SYNC-DL sign indicating number frequency domain sequence and carry out contraposition and be divided by, obtain the contraposition value of being divided by;

Successively the described contraposition value of being divided by is carried out inverse Fourier transform, respectively organized the channel estimating of SYNC-DL sign indicating number.

Preferably, step (C2) specifically comprises:

According to channel estimation results, calculate the power of each point in every group of SYNC-DL sign indicating number successively, select the signal strength signal intensity of wherein maximum performance number as this group SYNC-DL sign indicating number;

According to the signal strength signal intensity of each group SYNC-DL sign indicating number, select one group of the strongest SYNC-DL sign indicating number of signal.

Preferably, in the step (C3), described activation condition is:

The signal strength signal intensity of the SYNC-DL sign indicating number that detected signal signal strength signal intensity 〉=α * first time of the SYNC-DL sign indicating number that signal is the strongest is the strongest, wherein, 0.125≤α≤0.25.

Preferably, in the step (C3), behind the SYNC-DL sign indicating number collection that the SYNC-DL sign indicating number adding that signal is the strongest activates, also comprise:

Whether the number of times that determining step (C1) is carried out reaches set point, if, detection of end flow process then, otherwise, execution in step (C4).

Described set point is the treatable co-frequency cell number of user terminal.

Preferably, step (C4) also comprises the step of channel estimating being carried out noise removing before.

Preferably, the described step that channel estimating is carried out noise removing specifically comprises:

Setting comprises the channel profile window of performance number maximum point;

With the point outside the channel profile window scope as noise, and calculating noise power;

With the point outside the channel profile window scope and performance number less than min (T ₁* noise power, T ₂The channel estimating component of some correspondence * performance number maximum point power) composes zero, wherein, and 0.03125≤T ₁≤ 0.0625,4≤T ₂≤ 8.

Preferably, step (C2) specifically comprises:

According to the channel estimation results after the noise removing, calculate successively the non-vanishing point of performance number in every group of SYNC-DL sign indicating number power and, with this power with as the signal strength signal intensity of this group SYNC-DL sign indicating number;

According to the signal strength signal intensity of each group SYNC-DL sign indicating number, select one group of the strongest SYNC-DL sign indicating number of signal.

Preferably, in the step (C4), the strongest SYNC-DL sign indicating number composition of signal in the actual reception SYNC-DL sign indicating number frequency domain sequence is carried out Interference Cancellation, the process of the actual reception SYNC-DL sign indicating number frequency domain sequence that obtains upgrading specifically comprises:

Channel estimating after the strongest SYNC-DL sign indicating number of the power noise removing is carried out Fourier transform, obtain its frequency domain sequence;

The strongest practical SYNC-DL sign indicating number frequency domain sequence of channel estimating frequency domain sequence after the strongest SYNC-DL sign indicating number of the power noise removing and power is carried out contraposition multiply each other, obtain the contraposition value that multiplies each other;

Actual reception SYNC-DL sign indicating number frequency domain sequence and the described contraposition value that multiplies each other is carried out contraposition and subtracted each other the actual reception SYNC-DL sign indicating number frequency domain sequence that obtains upgrading.

Preferably, in the step (C4), the strongest SYNC-DL sign indicating number composition of signal in the actual reception SYNC-DL sign indicating number frequency domain sequence is carried out Interference Cancellation, the process of the actual reception SYNC-DL sign indicating number frequency domain sequence that obtains upgrading specifically comprises:

The practical SYNC-DL sign indicating number the strongest to the channel estimating after the strongest SYNC-DL sign indicating number of the power noise removing and power carries out the circular convolution computing, obtains the circular convolution operation values;

Actual reception SYNC-DL sign indicating number and described circular convolution operation values are carried out contraposition subtract each other the actual reception SYNC-DL sign indicating number that obtains upgrading;

The actual reception SYNC-DL sign indicating number that upgrades is carried out Fourier transform, the actual reception SYNC-DL sign indicating number frequency domain sequence that obtains upgrading.

A kind of checkout gear of common frequency community downlink synchronous code comprises, practical down-going synchronous code generator, Fourier transformer, down-going synchronous code detectors, wherein:

Described practical down-going synchronous code generator is used for according to basic SYNC-DL sign indicating number, and generating length is the practical SYNC-DL sign indicating number of actual reception SYNC-DL code length;

Described Fourier transformer is used for that actual reception SYNC-DL sign indicating number and each are organized practical SYNC-DL sign indicating number and carries out Fourier transform, obtains corresponding frequency domain sequence;

Described down-going synchronous code detectors is used for according to actual reception SYNC-DL sign indicating number frequency domain sequence and practical SYNC-DL sign indicating number frequency domain sequence, the SYNC-DL sign indicating number collection that the mode by counteracting serial interference obtains activating.

Preferably, described descending synchronous code detector specifically comprises:

Channel estimator is used for according to actual reception SYNC-DL sign indicating number frequency domain sequence and practical SYNC-DL sign indicating number frequency domain sequence, calculates the channel estimating of respectively organizing the SYNC-DL sign indicating number respectively;

The strongest down-going synchronous code detectors is used for according to channel estimation results, selects one group of the strongest SYNC-DL sign indicating number of signal;

Activate decision device, be used to judge whether the strongest SYNC-DL sign indicating number of described signal satisfies activation condition, and when satisfying activation condition, it is added the SYNC-DL sign indicating number collection that activates;

Noise eliminator is used for channel estimating is carried out noise removing;

Interference offset device is used for the strongest SYNC-DL sign indicating number composition of actual reception SYNC-DL sign indicating number frequency domain sequence signal being carried out Interference Cancellation, the actual reception SYNC-DL sign indicating number frequency domain sequence that obtains upgrading.

The method of the invention and device are handled the SYNC-DL sign indicating number that receives by the mode that Fourier transform combines with counteracting serial interference, thereby detect the SYNC-DL sign indicating number information of each co-frequency cell exactly, have reduced co-channel interference effectively.

Description of drawings

Fig. 1 is a TD-SCDMA system frame structure schematic diagram;

Fig. 2 is the detection method flow chart of the described common frequency community downlink synchronous code of the embodiment of the invention;

The flow chart of the SYNC-DL sign indicating number collection that Fig. 3 obtains activating for the mode by counteracting serial interference in the described method of the embodiment of the invention;

Fig. 4 is the checkout gear structural representation of the described common frequency community downlink synchronous code of the embodiment of the invention;

Fig. 5 is the concrete structure schematic diagram of the described down-going synchronous code detectors of the embodiment of the invention;

The workflow schematic diagram of the described down-going synchronous code detectors of Fig. 6 embodiment of the invention.

Embodiment

For making the purpose, technical solutions and advantages of the present invention clearer, describe the present invention below in conjunction with the accompanying drawings and the specific embodiments.

Fig. 1 is a TD-SCDMA system frame structure schematic diagram.Among the figure, TS0～TS6 represents 7 business time-slots; GP represents protection at interval, and GP does not send any signal in the period; DwPTS represents descending pilot frequency time slot; UpPTS represents uplink pilot time slot.

The SYNC-DL sign indicating number is arranged in DwPTS, and length is 64.In actual communication systems, when not setting up synchronously,, receive length and be greater than 64 usually for the SYNC-DL coded signal that makes reception drop-out not, for example the GP with each 32 chip (chip) of SYNC sign indicating number two ends receives in the lump.By frame structure as can be known, do not introducing under the situation that adjacent time-slots disturbs, the reception length range of SYNC-DL sign indicating number is 64～(32+64+96), promptly 64～192.The reception length of supposing the SYNC-DL sign indicating number is L, will receive SYNC-DL sign indicating number part up-sampling during actual reception, supposes that the up-sampling rate is N (N＞0), and the SYNC-DL code length that in fact finally receives so is RL=N * L.

Please refer to Fig. 2, the detection method flow chart for the described common frequency community downlink synchronous code of the embodiment of the invention may further comprise the steps:

Step 201, the basic SYNC-DL sign indicating number of basis, generating length is the practical SYNC-DL sign indicating number of actual reception SYNC-DL code length.

Can handle basic SYNC-DL sign indicating number by the mode of up-sampling and zero padding, thereby generate practical SYNC-DL sign indicating number.

Suppose that it is B that i organizes basic SYNC-DL sign indicating number _i, B _iLength be 64, the practical SYNC-DL sign indicating number of generation is M _i, M _iLength be RL; Wherein, i=0,1 ... 31.

At first obtain 0 sequence:

Finish up-sampling:

Then, to B _i' mend that (RL-64 * N) is individual 0, obtains the long M of RL of being _i:

0≤q≤RL-64×N

Certainly, if when receiving, do not have up-sampling, so directly to B _iMend 0 and obtain M _i

Step 202, respectively to actual reception SYNC-DL sign indicating number with respectively organize practical SYNC-DL sign indicating number and carry out Fourier transform, obtain corresponding frequency domain sequence.

With actual reception to length be the SYNC-DL sign indicating number RM of RL and 32 group leaders M for RL _iMake Fourier transform, obtain corresponding frequency domain sequence.Especially, satisfy RL=2 as RL ^m, when m is integer, can adopt fast Fourier transform (FFT) to finish this computing.For example, the GP with SYNC-DL sign indicating number and each 32chip of two ends thereof receives in the lump with twice up-sampling rate, promptly total reception length RL=(32+64+32) * 2=256.The frequency domain sequence that obtains is respectively:

F_RM＝FFT(RM)

F_M _i＝FFT(M _i)

Step 203, according to actual reception SYNC-DL sign indicating number frequency domain sequence and practical SYNC-DL sign indicating number frequency domain sequence, the SYNC-DL sign indicating number collection that the mode by counteracting serial interference obtains activating.

Under with the frequency situation, the SYNC-DL sign indicating number that receives is the signal that the SYNC-DL sign indicating number of a plurality of adjacent co-frequency cells is superimposed.Because the SYNC-DL sign indicating number of each sub-district signal strength signal intensity when arriving UE varies in size, and can detect the strongest SYNC-DL sign indicating number of signal earlier like this.In RM, its composition is removed (being Interference Cancellation) then, continue to detect time strong SYNC-DL coded signal (promptly having carried out the peak signal behind the Interference Cancellation) in this signal, and by that analogy.If the treatable co-frequency cell number of UE is cell_num, the method by the embodiment of the invention can detect cell_num SYNC-DL sign indicating number at most so, i.e. the cell_num that signal is the strongest SYNC-DL sign indicating number.

Please refer to Fig. 3, the flow chart of the SYNC-DL sign indicating number collection that obtains activating for the mode by counteracting serial interference in the described method of the embodiment of the invention may further comprise the steps:

Step 301, according to actual reception SYNC-DL sign indicating number frequency domain sequence and practical SYNC-DL sign indicating number frequency domain sequence, calculate the channel estimating respectively organize the SYNC-DL sign indicating number respectively.

Successively actual reception SYNC-DL sign indicating number frequency domain sequence F_RM and each are organized practical SYNC-DL sign indicating number frequency domain sequence F_M _iCarry out contraposition and be divided by, obtain the contraposition value of being divided by; Successively the described contraposition value of being divided by is carried out fast adverse Fourier transform (IFFT), respectively organized the channel estimating CHE of SYNC-DL sign indicating number _i':

CHE _i′＝IFFT(F_RM./F_M _i)

Step 302, according to channel estimation results, select one group of the strongest SYNC-DL sign indicating number of signal.

The embodiment of the invention has provided two kinds of implementations selecting the strongest SYNC-DL sign indicating number of signal:

A kind of is the channel estimating CHE that utilizes noise removing preceding _i', calculate the power of each point in every group of SYNC-DL sign indicating number successively, select the signal strength signal intensity of wherein maximum performance number as this group SYNC-DL sign indicating number; According to the signal strength signal intensity of each group SYNC-DL sign indicating number, select one group of the strongest SYNC-DL sign indicating number of signal.

Another is earlier to CHE _i' do noise removing to handle (represent this processing with PP, concrete processing procedure is described below), utilize the channel estimating CHE after the noise removing _i, calculate successively the non-vanishing point of performance number in every group of SYNC-DL sign indicating number power and, with this power with as the signal strength signal intensity of this group SYNC-DL sign indicating number; According to the signal strength signal intensity of each group SYNC-DL sign indicating number, select one group of the strongest SYNC-DL sign indicating number of signal.

Suppose the channel estimating CHE of current total p SYNC-DL sign indicating number _i', its sequence number is respectively i ₁, i ₂... i _P, need from this p SYNC-DL sign indicating number, select the strongest one group of signal.

Computing flow process according to first kind of implementation is:

At first, calculate CHE _Ik' (k=1,2 ... p) power of each point obtains its power sequence Power in _Ik, select a wherein maximum performance number and remember that doing sequence number is i _kThe signal strength signal intensity S of SYNC-DL sign indicating number _Ik, that is:

${\mathrm{Power}}_{i_k,n}={\left|{\mathrm{CHE}}_{i_k,n}^{\′}\right|}^2$

$S_{i_k}=\max \left({\mathrm{Power}}_{i_k,n}\right),$ n＝0，1，…RL-1

Then, select { S _IkIn maximum S _Imax:

$S_{i_{\max }}=\max \left(S_{i_k}\right)$

Computing flow process according to second kind of implementation is:

At first, to CHE _Ik' do the noise removing processing to obtain CHE _Ik, calculate CHE _IkIn the sequence power of the non-vanishing point of performance number and, with this power and as its signal strength signal intensity, that is:

${\mathrm{CHE}}_{i_k}=\mathrm{PP}\left({\mathrm{CHE}}_{i_k}^{\′}\right)$

$S_{i_k}=\underset{{\mathrm{CHE}}_{i_k,n\≠0}}{\mathrm{\Σ}}{\left|{\mathrm{CHE}}_{i_k,n}\right|}^2$

Then, select { S _IkIn maximum S _Imax:

$s_{i_{\max }}=\max \left(S_{i_k}\right)$

Step 303, judge whether the strongest SYNC-DL sign indicating number of described signal satisfies activation condition, if, then it is added execution in step 304 behind the SYNC-DL sign indicating number collection that activates, otherwise, the detection of end flow process.

If the signal strength signal intensity of first inspection SYNC-DL sign indicating number is

(i.e. the signal strength signal intensity of the SYNC-DL sign indicating number that detected signal is the strongest for the first time), the signal strength signal intensity that activates the SYNC-DL sign indicating number that detects judgement is S _Imax, the judgement mode is as follows:

If court verdict for activating, then upgrades the SYNC-DL sign indicating number collection ASS that activates:

ASS＝ASS∪{i _max}

Wherein, ASS is initially empty set, and α is for activating a parameter in the detector, and its span is preferably 0.125～0.25.Obviously, first inspection SYNC-DL sign indicating number satisfies activation condition.

In an embodiment of the present invention, add the SYNC-DL sign indicating number collection of activation at the SYNC-DL sign indicating number that signal is the strongest after, also comprise: whether the number of times that determining step 301 is carried out reaches set point, if, detection of end flow process then, wherein, described set point is the treatable co-frequency cell number of UE, i.e. cell_num.

Step 304, the strongest SYNC-DL sign indicating number composition of signal in the actual reception SYNC-DL sign indicating number frequency domain sequence is carried out Interference Cancellation, the actual reception SYNC-DL sign indicating number frequency domain sequence that obtains upgrading, and to the remaining operation of respectively organizing SYNC-DL sign indicating number continuation execution from step 301 beginning.

The function of Interference Cancellation is from received signal the composition of the SYNC-DL sign indicating number that has detected to be removed.In an embodiment of the present invention, the scheme of Interference Cancellation has two kinds: frequency domain interference is offset and the time domain Interference Cancellation.

Offset for frequency domain interference, its Interference Cancellation computing is carried out at frequency domain, and the Interference Cancellation process is:

Channel estimating after the strongest SYNC-DL sign indicating number of the power noise removing is carried out Fourier transform, obtain its frequency domain sequence; The strongest practical SYNC-DL sign indicating number frequency domain sequence of channel estimating frequency domain sequence after the strongest SYNC-DL sign indicating number of the power noise removing and power is carried out contraposition multiply each other, obtain the contraposition value that multiplies each other; Actual reception SYNC-DL sign indicating number frequency domain sequence and the described contraposition value that multiplies each other is carried out contraposition and subtracted each other the actual reception SYNC-DL sign indicating number frequency domain sequence that obtains upgrading.

The specific algorithm flow process is:

At first, calculate F_CHE _Imax,

$F\_{\mathrm{CHE}}_{i_{\max }}=\mathrm{FFT}\left(\mathrm{CH}{E}_{i_{\max }}\right)$

Then, upgrade F_RM,

$F\_\mathrm{RM}=F\_\mathrm{RM}.-F\_\mathrm{CH}{E}_{i_{\max }}.*F\_M_{i_{\max }}$

For the time domain Interference Cancellation, its Interference Cancellation computing is carried out in time domain, and the Interference Cancellation process is:

The practical SYNC-DL sign indicating number the strongest to the channel estimating after the strongest SYNC-DL sign indicating number of the power noise removing and power carries out the circular convolution computing, obtains the circular convolution operation values; Actual reception SYNC-DL sign indicating number and described circular convolution operation values are carried out contraposition subtract each other the actual reception SYNC-DL sign indicating number that obtains upgrading; The actual reception SYNC-DL sign indicating number that upgrades is carried out Fourier transform, the actual reception SYNC-DL sign indicating number frequency domain sequence that obtains upgrading.

The specific algorithm flow process is:

At first, upgrade RM,

$\mathrm{RM}=\mathrm{RM}.-{\mathrm{CHE}}_{i_{\max }}\⊗M_{i_{\max }}$

Then, upgrade F_RM,

F_RM＝FFT(RM)

Below introduce the method for in the embodiment of the invention channel estimating being carried out noise removing, also promptly finish the PP processing computing that preamble is mentioned.

Because always there is such or such noise in actual wireless environment, and with under the situation frequently, the UE that belongs to different districts can become interference each other.So with the channel estimating that obtains under the situation frequently,, can reflect outside the effective diameter of real channel situation, also have some falsenesses, the invalid footpath that peakedness ratio is less, i.e. noise component(s) except peakedness ratio is bigger.In order in the process of Interference Cancellation, not introduce these noises, resulting channel estimating need be carried out the processing of a noise removing.

Here, suppose channel estimating CHE _i' pairing power sequence is Power _i, Power _iIn more prominent be the j point, its value is for S _j, the processing procedure of noise removing is:

At first, determine the position range [PosStart, PosEnd] of channel profile window.Definite principle of position range is in must being included in the j point, and is specific as follows:

PosStart＝max(0，j-w ₁×N)

PosEnd＝min(RL-1，j+w ₂×N)

The w here ₁And w ₂Be two parameters of PP process.w ₁Expression wants to keep that the chip lengths of the profile window before the j point, preferred value are 5; w ₂Expression wants to keep that the chip lengths of the profile window after the j point, preferred value are 10.

Then, calculating channel is estimated CHE _i' in noise power.At CHE _i' in, the point outside the profile window scope can be regarded noise as, and with its calculating noise power P owNoise.Algorithm is as follows:

$\mathrm{PowNoise}=\frac{\underset{n\∉\[\mathrm{PosEnd},\mathrm{PosStart}\]}{\mathrm{\Σ}}\mathrm{Powe}{r}_{i,n}}{\mathrm{RL}-(\mathrm{PosEnd}-\mathrm{PosStart}+1)}$

At last, eliminate noise, obtain the channel estimating CHE after the denoising _i:

${\mathrm{CHE}}_{i,n}=\left\{\begin{array}{cc}0& \mathrm{ifn}\&NotElement;\&lsqb;\mathrm{PosStart},\mathrm{PosEnd}\&rsqb;\\ 0& \mathrm{elseifPowe}{r}_{i,n}<\min ({\mathrm{<figure-callout\; id="2"\; label="T"\; filenames="A20071006296400241.png"\; state="\{\{state\}\}">T</figure-callout>}}_2*S_j,{\mathrm{<figure-callout\; id="1"\; label="T"\; filenames="A20071006296400241.png"\; state="\{\{state\}\}">T</figure-callout>}}_1*\mathrm{PowNoise})\\ {\mathrm{CHE}}_{i,n}& \mathrm{else}\end{array}\right.$

Wherein, T ₁And T ₂Be two parameters that are used for denoising, T ₁Preferred value is 0.03125～0.0625, T ₂Preferred value is 4～8.

The detection method of common frequency community downlink synchronous code in corresponding the above embodiment of the present invention, the embodiment of the checkout gear of a kind of common frequency community downlink synchronous code of corresponding here proposition.Please refer to Fig. 4, this figure is the checkout gear structural representation of the described common frequency community downlink synchronous code of the embodiment of the invention.Its composition mainly comprises, practical down-going synchronous code generator 10, Fourier transformer 20, down-going synchronous code detectors 30, wherein:

Practical down-going synchronous code generator 10 is used for according to basic SYNC-DL sign indicating number, and generating length is the practical SYNC-DL sign indicating number of actual reception SYNC-DL code length; Particularly, practical down-going synchronous code generator 10 is handled basic SYNC-DL sign indicating number by the mode of up-sampling and/or zero padding, thereby generates practical SYNC-DL sign indicating number;

Fourier transformer 20 is used for that actual reception SYNC-DL sign indicating number and each are organized practical SYNC-DL sign indicating number and carries out Fourier transform, obtains corresponding frequency domain sequence;

Down-going synchronous code detectors 30 is used for according to actual reception SYNC-DL sign indicating number frequency domain sequence and practical SYNC-DL sign indicating number frequency domain sequence, the SYNC-DL sign indicating number collection that the mode by counteracting serial interference obtains activating.

Please refer to Fig. 5, this figure is the concrete structure schematic diagram of the described down-going synchronous code detectors 30 of the embodiment of the invention, comprise, and channel estimator 31, the strongest down-going synchronous code detectors 32, activation decision device 33, noise eliminator 34, interference offset device 35, wherein:

Channel estimator 31 is used for according to actual reception SYNC-DL sign indicating number frequency domain sequence and practical SYNC-DL sign indicating number frequency domain sequence, calculates the channel estimating of respectively organizing the SYNC-DL sign indicating number respectively;

The strongest down-going synchronous code detectors 32 is used for according to channel estimation results, selects one group of the strongest SYNC-DL sign indicating number of signal;

Activate decision device 33, be used to judge whether the strongest SYNC-DL sign indicating number of described signal satisfies activation condition, and when satisfying activation condition, it is added the SYNC-DL sign indicating number collection that activates;

Noise eliminator 34 is used for channel estimating is carried out noise removing;

Interference offset device 35 is used for the strongest SYNC-DL sign indicating number composition of actual reception SYNC-DL sign indicating number frequency domain sequence signal being carried out Interference Cancellation, the actual reception SYNC-DL sign indicating number frequency domain sequence that obtains upgrading.

In this embodiment, noise eliminator 34 is that the channel estimating of the strongest SYNC-DL sign indicating number is carried out noise removing.In another embodiment of the present invention, noise eliminator 34 can also carry out noise removing to all channel estimating of respectively organizing the SYNC-DL sign indicating number, different is that the strongest down-going synchronous code detectors 32 is according to the channel estimation results after the noise removing, selects one group of the strongest SYNC-DL sign indicating number of signal.

Please refer to Fig. 6, provided the workflow schematic diagram of the described down-going synchronous code detectors 30 of the embodiment of the invention.Wherein, the treatable co-frequency cell number of UE, i.e. cell_num=4.

Calculate channel estimating at first, successively corresponding to 32 groups of SYNC-DL sign indicating numbers:

CHE _i′＝IFFT(F_RM./F_M _i)

(finishing in the channel estimator 31)

Secondly, according to CHE _i' select the strongest SYNC-DL sign indicating number of signal, and upgrade ASS in view of the above:

Utilize the strongest down-going synchronous code detectors 32 to detect CHE _i' SYNC-DL sign indicating number that middle signal is the strongest obtains i _MaxAnd S _Imax

S with this moment _ImaxNote is done first inspection SYNC-DL coded signal intensity, promptly

$\tilde{S}=S_{i_{\max }}=\max \left(S_i\right)$

(finishing in the strongest down-going synchronous code detectors 32)

Upgrade the ASS set,

ASS＝ASS?∪{i _max}

(activate in the decision device 33 and finish)

Once more, to CHE _Imax' do the noise removing processing to obtain CHE _Imax, promptly

${\mathrm{CHE}}_{i_{\max }}=\mathrm{PP}\left({\mathrm{CHE}}_{i_{\max }}^{\&prime;}\right)$

(finishing in the noise eliminator 34)

At last, upgrade F_RM:

If use frequency domain interference to offset, its computing flow process is:

$F\_{\mathrm{CHE}}_{i_{\max }}=\mathrm{FFT}\left(\mathrm{CH}{E}_{i_{\max }}\right)$

$F\_\mathrm{RM}=F\_\mathrm{RM}.-F\_{\mathrm{CHE}}_{i_{\max }}.*F\_M_{i_{\max }}$

If use the time domain Interference Cancellation, its computing flow process is:

$\mathrm{RM}=\mathrm{RM}.-{\mathrm{CHE}}_{i_{\max }}\&CircleTimes;M_{i_{\max }}$

F_RM＝FFT(RM)

(finishing in the interference offset device 35)

Next, detect time strong descending synchronous code, process is:

At first, utilize the F_RM after upgrading, calculate the channel estimating that its sequence number i does not belong to each SYNC-DL sign indicating number of ASS successively,

CHE _i′＝IFFT(F_RM./F_M _i) iASS

(finishing in the channel estimator 31)

Secondly, according to CHE _i', i  ASS selects the strongest SYNC-DL sign indicating number of signal, and upgrades ASS in view of the above:

Utilize the strongest SYNC-DL code detectors 32 to detect CHE _i', the strongest SYNC-DL sign indicating number of signal draws i among the i  ASS _MaxAnd S _Imax

(finishing in the strongest down-going synchronous code detectors 32)

Utilize

And S _ImaxTo descending synchronous code S _ImaxDo to activate and detect, if S _ImaxBe judged as un-activation, then finish to check flow process, otherwise upgrade ASS,

ASS＝ASS?∪{i _max}

If this moment, ASS set element number reached cell_num, also finish to check flow process.Otherwise, continue down computing.

(activate in the decision device 33 and finish)

Once more, to CHE _Imax' do the noise removing processing to obtain CHE _Imax, promptly

${\mathrm{CHE}}_{i_{\max }}=\mathrm{PP}\left({\mathrm{CHE}}_{i_{\max }}^{\&prime;}\right)$

(finishing in the noise eliminator 34)

At last, upgrade F_RM:

If use frequency domain interference to offset, its computing flow process is:

$F\_{\mathrm{CHE}}_{i_{\max }}=\mathrm{FFT}\left({\mathrm{CHE}}_{i_{\max }}\right)$

$F\_\mathrm{RM}=F\_\mathrm{RM}.-F\_{\mathrm{CHE}}_{i_{\max }}.*F\_M_{i_{\max }}$

If use the time domain Interference Cancellation, its computing flow process is:

$\mathrm{RM}=\mathrm{RM}.-{\mathrm{CHE}}_{i_{\max }}\&CircleTimes;M_{i_{\max }}$

F_RM＝FFT(RM)

(finishing in the interference offset device 35)

If flow process does not finish, repeat said process, move cell_num time at most.

After processing procedure is finished, the last ASS set of upgrading, wherein each element is the serial number information of the SYNC-DL sign indicating number that comprised among the RM, promptly detects to include which group SYNC-DL sign indicating number among the RM.

In fact, range of application of the present invention is not limited to the SYNC-DL sign indicating number and detects, and all is suitable for for all similar situations.Described analogue reduces: receiver receives the multichannel pilot signal simultaneously, and each road pilot signal all is the signal that is arrived receiver by the training sequence of transmitter emission at the process wireless channel later on; Each road pilot signal is used different training sequences, and the multichannel pilot signal is superimposed at receiving terminal; Receiver need pick out and all contain those several training sequences in received mixed signal, and employed training sequence comes from the set of a known training sequence in the system.

Should be noted that at last, above embodiment is only unrestricted in order to technical scheme of the present invention to be described, those of ordinary skill in the art is to be understood that, can make amendment or be equal to replacement technical scheme of the present invention, and not breaking away from the spiritual scope of technical solution of the present invention, it all should be encompassed in the middle of the claim scope of the present invention.

Claims (15)

1. the detection method of a common frequency community downlink synchronous code is characterized in that, may further comprise the steps:

(A) according to basic down-going synchronous SYNC-DL sign indicating number, generating length is the practical SYNC-DL sign indicating number of actual reception SYNC-DL code length;

(B) respectively actual reception SYNC-DL sign indicating number and each are organized practical SYNC-DL sign indicating number and carry out Fourier transform, obtain corresponding frequency domain sequence;

(C) according to actual reception SYNC-DL sign indicating number frequency domain sequence and practical SYNC-DL sign indicating number frequency domain sequence, the SYNC-DL sign indicating number collection that the mode by counteracting serial interference obtains activating.

2. the method for claim 1 is characterized in that:

In the step (A), basic SYNC-DL sign indicating number is handled, thereby generated practical SYNC-DL sign indicating number by the mode of up-sampling and/or zero padding.

3. the method for claim 1 is characterized in that, step (C) specifically comprises step:

(C1), calculate the channel estimating of respectively organizing the SYNC-DL sign indicating number respectively according to actual reception SYNC-DL sign indicating number frequency domain sequence and practical SYNC-DL sign indicating number frequency domain sequence;

(C2), select one group of the strongest SYNC-DL sign indicating number of signal according to channel estimation results;

(C3) judge whether the strongest SYNC-DL sign indicating number of described signal satisfies activation condition, if, then with execution in step (C4) behind the SYNC-DL sign indicating number collection of its adding activation, otherwise, the detection of end flow process;

(C4) the strongest SYNC-DL sign indicating number composition of signal in the actual reception SYNC-DL sign indicating number frequency domain sequence is carried out Interference Cancellation, the actual reception SYNC-DL sign indicating number frequency domain sequence that obtains upgrading, and to the remaining operation of respectively organizing SYNC-DL sign indicating number continuation execution from step (C1) beginning.

4. method as claimed in claim 3 is characterized in that, step (C1) specifically comprises:

Successively actual reception SYNC-DL sign indicating number frequency domain sequence and each are organized practical SYNC-DL sign indicating number frequency domain sequence and carry out contraposition and be divided by, obtain the contraposition value of being divided by;

Successively the described contraposition value of being divided by is carried out inverse Fourier transform, respectively organized the channel estimating of SYNC-DL sign indicating number.

5. method as claimed in claim 3 is characterized in that, step (C2) specifically comprises:

According to channel estimation results, calculate the power of each point in every group of SYNC-DL sign indicating number successively, select the signal strength signal intensity of wherein maximum performance number as this group SYNC-DL sign indicating number;

According to the signal strength signal intensity of each group SYNC-DL sign indicating number, select one group of the strongest SYNC-DL sign indicating number of signal.

6. method as claimed in claim 3 is characterized in that, in the step (C3), described activation condition is:

The signal strength signal intensity of the SYNC-DL sign indicating number that detected signal signal strength signal intensity 〉=α * first time of the SYNC-DL sign indicating number that signal is the strongest is the strongest, wherein, 0.125≤α≤0.25.

7. method as claimed in claim 3 is characterized in that, in the step (C3), behind the SYNC-DL sign indicating number collection that the SYNC-DL sign indicating number adding that signal is the strongest activates, also comprises:

Whether the number of times that determining step (C1) is carried out reaches set point, if, detection of end flow process then, otherwise, execution in step (C4).

8. method as claimed in claim 7 is characterized in that:

Described set point is the treatable co-frequency cell number of user terminal.

9. method as claimed in claim 3 is characterized in that:

Step (C4) also comprises the step of channel estimating being carried out noise removing before.

10. method as claimed in claim 9 is characterized in that, the described step that channel estimating is carried out noise removing specifically comprises:

Setting comprises the channel profile window of performance number maximum point;

With the point outside the channel profile window scope as noise, and calculating noise power;

With the point outside the channel profile window scope and performance number less than min (T ₁* noise power, T ₂The channel estimating component of some correspondence * performance number maximum point power) composes zero, wherein, and 0.03125≤T ₁≤ 0.0625,4≤T ₂≤ 8.

11. method as claimed in claim 9 is characterized in that, step (C2) specifically comprises:

According to the channel estimation results after the noise removing, calculate successively the non-vanishing point of performance number in every group of SYNC-DL sign indicating number power and, with this power with as the signal strength signal intensity of this group SYNC-DL sign indicating number;

According to the signal strength signal intensity of each group SYNC-DL sign indicating number, select one group of the strongest SYNC-DL sign indicating number of signal.

12. method as claimed in claim 9, it is characterized in that, in the step (C4), the strongest SYNC-DL sign indicating number composition of signal in the actual reception SYNC-DL sign indicating number frequency domain sequence is carried out Interference Cancellation, the process of the actual reception SYNC-DL sign indicating number frequency domain sequence that obtains upgrading specifically comprises:

Channel estimating after the strongest SYNC-DL sign indicating number of the power noise removing is carried out Fourier transform, obtain its frequency domain sequence;

The strongest practical SYNC-DL sign indicating number frequency domain sequence of channel estimating frequency domain sequence after the strongest SYNC-DL sign indicating number of the power noise removing and power is carried out contraposition multiply each other, obtain the contraposition value that multiplies each other;

Actual reception SYNC-DL sign indicating number frequency domain sequence and the described contraposition value that multiplies each other is carried out contraposition and subtracted each other the actual reception SYNC-DL sign indicating number frequency domain sequence that obtains upgrading.

13. method as claimed in claim 9, it is characterized in that, in the step (C4), the strongest SYNC-DL sign indicating number composition of signal in the actual reception SYNC-DL sign indicating number frequency domain sequence is carried out Interference Cancellation, the process of the actual reception SYNC-DL sign indicating number frequency domain sequence that obtains upgrading specifically comprises:

The practical SYNC-DL sign indicating number the strongest to the channel estimating after the strongest SYNC-DL sign indicating number of the power noise removing and power carries out the circular convolution computing, obtains the circular convolution operation values;

Actual reception SYNC-DL sign indicating number and described circular convolution operation values are carried out contraposition subtract each other the actual reception SYNC-DL sign indicating number that obtains upgrading;

The actual reception SYNC-DL sign indicating number that upgrades is carried out Fourier transform, the actual reception SYNC-DL sign indicating number frequency domain sequence that obtains upgrading.

14. the checkout gear of a common frequency community downlink synchronous code is characterized in that, comprises, practical down-going synchronous code generator, Fourier transformer, down-going synchronous code detectors, wherein:

Described practical down-going synchronous code generator is used for according to basic SYNC-DL sign indicating number, and generating length is the practical SYNC-DL sign indicating number of actual reception SYNC-DL code length;

Described Fourier transformer is used for that actual reception SYNC-DL sign indicating number and each are organized practical SYNC-DL sign indicating number and carries out Fourier transform, obtains corresponding frequency domain sequence;

Described down-going synchronous code detectors is used for according to actual reception SYNC-DL sign indicating number frequency domain sequence and practical SYNC-DL sign indicating number frequency domain sequence, the SYNC-DL sign indicating number collection that the mode by counteracting serial interference obtains activating.

15. want 14 described devices, it is characterized in that described descending synchronous code detector specifically comprises as right:

Channel estimator is used for according to actual reception SYNC-DL sign indicating number frequency domain sequence and practical SYNC-DL sign indicating number frequency domain sequence, calculates the channel estimating of respectively organizing the SYNC-DL sign indicating number respectively;

The strongest down-going synchronous code detectors is used for according to channel estimation results, selects one group of the strongest SYNC-DL sign indicating number of signal;

Activate decision device, be used to judge whether the strongest SYNC-DL sign indicating number of described signal satisfies activation condition, and when satisfying activation condition, it is added the SYNC-DL sign indicating number collection that activates;

Noise eliminator is used for channel estimating is carried out noise removing;

Interference offset device is used for the strongest SYNC-DL sign indicating number composition of actual reception SYNC-DL sign indicating number frequency domain sequence signal being carried out Interference Cancellation, the actual reception SYNC-DL sign indicating number frequency domain sequence that obtains upgrading.

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