CN105764153A - Signature sequence detection method and apparatus of uplink random access - Google Patents

Abstract

The invention relates to the field of communication, and discloses a signature sequence detection method and apparatus of uplink random access. The method comprises the following steps: according to a power time-delay spectrum of a ZC sequence, obtaining a power time-delay spectrum sequence; deleting interference object echo sampling signals in the power time-delay spectrum, summing residual sampling signals, from a noise background, in the power time-delay spectrum after the interference object echo sampling signals are detected and taking an obtained sum as noise power; obtaining a noise power threshold factor; and according to the noise power and the noise power threshold factor, obtaining a threshold subjected to signature sequence detection, and carrying out peak search by use of the threshold. According to the embodiments of the invention, by use of a noise power estimation method based on automatic average deletion, under the condition that signature sequence signals are quite weak and quite a lot of signature sequence signals appear simultaneously, an accurate detection result can still be obtained.

Description

The signature sequence detection method of a kind of uplink random access and device

Technical field

The present invention relates to the communications field, the signature sequence detection method accessed particularly to a kind of uplink random and device.

Background technology

At LTE (LongTermEvolution, Long Term Evolution) in system, radio access technology is an important technology of subscriber equipment (UserEquipment is called for short " UE ") Access Control, is that subscriber equipment is for carrying out up Timing Synchronization.

In LTE system, subscriber equipment by sending RACH on Physical Random Access Channel, RACH adopt the cyclic shift of Zadoff-Chu (ZC) sequence as targeting sequencing, in the process that uplink random accesses, need ZC is carried out signature sequence detection, and it needs to be determined that corresponding detection threshold value T when ZC is carried out signature sequence detection_det。

General, based on invariable false alerting principle, detection threshold T_detIt is represented by: T_det=γ_nT_r, wherein, γ_nFor noise power, T_rFor the noise power threshold factor.Assume L the complex random variable only comprising noiseFor statistical iteration with the multiple Gaussian random variable being distributed, then stochastic variable z_nca(τ) be degree of freedom it is 2N_aN_ncaCenter card side distribution stochastic variable, its average is:Wherein,Variance during for y (n) for noise, y (n) is the Baseband Receiver discrete signal comprising noise, N_caFor y (n) being carried out the length value of fast discrete Fourier transformation, andIt is compose (PDP) according to ZC sequence power time delay:Obtain, wherein,x_uN () is ZC root sequence, a is the antenna mark of receiver, and m is the repeatable block number of ZC sequence, and τ is corresponding to the cyclic shift of ZC basic sequence, and L represents the largest loop displacement of ZC root sequence.In real process, due to the more difficult acquisition of the statistical property of noise, usually by the general estimating noise power of detection sample of meansigma methods, it may be assumed thatWherein, T_{det_ini}For all detection sample means, N_sFor the corresponding sample number less than meansigma methods.

Above-mentioned to noise power γ_nMethod of estimation have that the suitability is big and the simple advantage of computing, but be not most efficient method at signature sequence signal more weak (under strong noise background) and more multiple signature sequence signal when occurring simultaneously.

Summary of the invention

It is an object of the invention to provide signature sequence detection method and device that a kind of uplink random accesses, make, when signature sequence signal more weak (under strong noise background) and more multiple signature sequence signal occur simultaneously, still to obtain accurate Detection results.

For solving above-mentioned technical problem, embodiments of the present invention provide the signature sequence detection method that a kind of uplink random accesses, and comprise the steps of

Obtain power time delay spectral sequence { z_nca(τ_i), wherein, 0≤i≤L-1, L represents the largest loop displacement of ZC root sequence, Z_nca(τ_i) represent ith sample signal in power time delay spectral sequence, τ_iCyclic shift corresponding to i-th ZC basic sequence；

Delete power time delay spectral sequence { z_nca(τ_i) in jamming target echo samples signal, sue for peace deleting the remaining sampled signal from noise background in the power time delay spectral sequence after described jamming target echo samples signal, and using obtained and as noise power γ_n；

Obtain noise power threshold factor T_r；

According to described noise power γ_nAnd noise power threshold factor T_r, obtain the thresholding T carrying out signature sequence detection_det, and utilize described thresholding T_detCarry out peak value searching.

Embodiments of the present invention additionally provide the signature sequence detecting device that a kind of uplink random accesses, and comprise: time delay spectral sequence acquisition module, noise power acquisition module, noise power threshold factor acquisition module and signature sequence detection module；

Described time delay spectral sequence acquisition module is used for obtaining power time delay spectral sequence { z_nca(τ_i), wherein, 0≤i≤L-1, L represents the largest loop displacement of ZC root sequence, Z_nca(τ_i) represent ith sample signal in power time delay spectral sequence, τ_iCyclic shift corresponding to i-th ZC basic sequence；

Described noise power acquisition module is used for deleting power time delay spectral sequence { z_nca(τ_i) in jamming target echo samples signal, sue for peace deleting the remaining sampled signal from noise background in the power time delay spectral sequence after described jamming target echo samples signal, and using obtained and as noise power γ_n；

Described noise power threshold factor acquisition module is used for obtaining noise power threshold factor T_r；

Described signature sequence detection module is for according to described noise power γ_nAnd noise power threshold factor T_r, obtain the thresholding T carrying out signature sequence detection_det, and utilize described thresholding T_detCarry out peak value searching.

Embodiment of the present invention in terms of existing technologies, adopts the method for estimation of the noise power deleted based on automatic average, deletes power time delay spectral sequence { z_nca(τ_i) in jamming target echo samples signal, sue for peace deleting the remaining sampled signal from noise background in the power time delay spectral sequence after described jamming target echo samples signal, and using obtained and as noise power γ_n, this acquisition noise power γ_nEven if method make when signature sequence signal more weak (under strong noise background) and more multiple signature sequence signal occur simultaneously, detection algorithm still can obtain accurate Detection results.

Further, described thresholding T_detFor: T_det=γ_nT_r；

Utilizing described thresholding T_detCarry out in the step of peak value searching, including following sub-step:

Judge described T_detWith z_nca(τ_i) magnitude relationship, if z_nca(τ_i)≥T_det, then z_nca(τ_i) for signature sequence；If z_nca(τ_i)<T_det, then z_nca(τ_i) for noise.By judging T_detWith z_nca(τ_i) magnitude relationship, identify power time delay spectrum PDP sequence in signature sequence, thus obtaining the request signal of up ZC sequence.

Further, in the step of described acquisition power time delay spectral sequence, including following sub-step:

Signal will be received and be converted to baseband signal；

Described baseband signal is carried out linear filtering；

To described carry out linear filtering after baseband signal sample；

Remove the Cyclic Prefix of the baseband signal after described sampling, obtain Baseband Receiver discrete signal y (n) comprising noise；

Described y (n) is carried out frequency domain conversion, subcarrier demapping, and after frequency domain is multiplied with described ZC sequence and passes through spatial transform, applies square-law, obtain ZC sequence power time delay spectrum PDP:DescribedWherein, a is the antenna mark of receiver, and m is the repeatable block number mark of ZC sequence, and τ is corresponding to the cyclic shift of ZC basic sequence, x_uN () is ZC root sequence；

Compose according to described ZC sequence power time delay, obtain described ZC sequence power time delay spectral sequence.Obtain ZC sequence power time delay spectrum, thus obtaining power time delay spectrum PDP sequence for the later stage and carrying out the thresholding T of signature sequence detection_detProvide possibility.

Further, described by the step receiving signal and being converted to baseband signal before, further comprising the steps of:

Determine whether that signal enters, and judging have signal to send, after entering, the request carrying out baseband signal conversion.First determine whether that signal enters, be conducive to the later stage in time the signal entered to be changed.

Accompanying drawing explanation

Fig. 1 is the flow chart of the signature sequence detection method that the uplink random according to this bright first embodiment accesses；

Fig. 2 is the structural representation that the Long Term Evolution RACH receiver according to first embodiment of the invention obtains the power time delay spectrum PDP of ZC sequence；

Fig. 3 is the signature sequence structure of the detecting device schematic diagram that the uplink random according to third embodiment of the invention accesses.

Detailed description of the invention

For making the object, technical solutions and advantages of the present invention clearly, below in conjunction with accompanying drawing, the embodiments of the present invention are explained in detail.But, it will be understood by those skilled in the art that in each embodiment of the present invention, propose many ins and outs in order to make reader be more fully understood that the application.But, even without these ins and outs with based on the many variations of following embodiment and amendment, it is also possible to realize the application each claim technical scheme required for protection.

First embodiment of the present invention relates to the signature sequence detection method that a kind of uplink random accesses.Due in radar theory, based on the noise power estimation method that automatic average is deleted, to radar reflection it is weak signal and intensive target detection scene demonstrates preferably performance.Based on this prompting, present embodiment adopts the noise power estimation method deleted based on automatic average to be applied to LTE uplink random and accesses the noise power estimation of signature sequence detection, when signature sequence signal more weak (under strong noise background) and more multiple signature sequence signal occur simultaneously, accurate Detection results still can be obtained.

Additionally, relative to noise power estimation, although the noise power estimation deleted based on automatic average has bigger computation complexity, but owing to the up detection of LTE is realized by base station, base station relative termination has stronger operational capability, realizes this algorithm in base station also relatively reasonable.

The idiographic flow of present embodiment is as shown in Figure 1.

In a step 101, Long Term Evolution RACH receiver obtains power time delay spectral sequence { z_nca(τ_i), wherein, 0≤i≤L-1, L represents the largest loop displacement of ZC root sequence, Z_nca(τ_i) represent ith sample signal in power time delay spectral sequence, τ_iCyclic shift corresponding to i-th ZC basic sequence.

Specifically, the signal received first is converted to baseband signal by receiver；Again through linear filter this baseband signal carried out linear filtering, and the baseband signal after linear filtering is sampled, Cyclic Prefix is removed, and obtains Baseband Receiver discrete signal y (n) comprising noise；It follows that again y (n) to be carried out frequency domain conversion, subcarrier demapping, and after frequency domain is multiplied with described ZC sequence and passes through spatial transform, apply square-law, obtain ZC sequence power time delay spectrum:Wherein,A is the antenna mark of receiver, and m is the repeatable block number mark of ZC sequence, and τ is corresponding to the cyclic shift of ZC basic sequence, x_uN () is ZC root sequence.Last according to ZC sequence power time delay spectrum, obtain ZC sequence power time delay spectral sequence.Owing to the acquisition process of ZC sequence power time delay spectral sequence is by existing techniques in realizing, present embodiment repeats no more.

And then, Long Term Evolution RACH receiver is composed according to the power time delay of this ZC sequence, obtains power time delay spectral sequence: { z_nca(τ_i), wherein,0≤i≤L-1, N_aFor reception antenna number, N_ncaFor ZC sequence repeat send block number.

In step 102 is to 108, power time delay spectral sequence { z deleted by Long Term Evolution RACH receiver_nca(τ_i) in jamming target echo samples signal, sue for peace deleting the remaining sampled signal from noise background in the power time delay spectral sequence after described jamming target echo samples signal, and using obtained and as noise power γ_n。

Specifically, in rapid 102, Long Term Evolution RACH receiver according to the size of amplitude to power time delay spectral sequence { z_nca(τ_i) be ranked up, generate new power time delay spectral sequence { z_nca(τ_i'), wherein, Z_nca(τ₀′)、Z_nca(τ₁′)、…、Z_nca(τ′_L-1) amplitude increase successively.

In step 103, Long Term Evolution RACH receiver is according to new power time delay spectral sequence { z_nca(τ_i'), set noise power γ_nEstimated value beWherein, 0≤j≤n_ini≤L-1；For set { z_nca(τ_i') in a part of sampled signal sum, can take hereWherein,Represent the integer upper limit taking L/4.

At step 104, Long Term Evolution RACH receiver is according to z_nca(τ) cumulative distribution function, and the mistake probability of erasure P set_fc, obtain threshold factor

Specifically, z_nca(τ) cumulative distribution function is:

$F^{\&prime;}\left(T_{n_{\mathrm{ini}}}\right)=1-e^{{-N}_a{N}_{\mathrm{nca}}{T}_{n_{\mathrm{ini}}}}\underset{k=0}{\overset{N_a{N}_{\mathrm{nca}}-1}{\mathrm{\&Sigma;}}}\frac{1}{k!}{\left(N_a{N}_{\mathrm{nca}}{T}_{n_{\mathrm{ini}}}\right)}^k;$

Probability of erasure P by mistake_fcFor noise being judged as useful signal and by its probability deleted from noise power estimation, it meets:NamelyIn conjunction with z given above_nca(τ) cumulative distribution function, thus drawing:Threshold factor can be obtained according to this formulaWherein, probability of erasure P is missed_fcBeing can be set according to the design requirement of communication system, its acquisition methods can pass through existing techniques in realizing, and present embodiment repeats no more.

In step 105, Long Term Evolution RACH receiver is according to described noise power γ_nEstimated value and threshold factor, set threshold values

In step 106, N=n is first taken_ini+ 1, it is judged that N > L-1 (i.e. n_ini+ 1 > L-1) whether set up, if setting up, then it is assumed that sampled signal Z_nca(τ₀′)、Z_nca(τ₁′)、…、Z_nca(τ′_L-1) it is all from noise background, and it is directly entered step 108.

Due in step 103, the noise power estimation value set as0≤j≤n_ini≤L-1；Therefore, n is worked as_ini+ 1 > when L-1 sets up, i.e. n_ini> L-2, now n_iniL-1 can only be taken, say, thatInclude set { z_nca(τ_i') all sampled signals, i.e. sampled signal Z_nca(τ₀′)、Z_nca(τ₁′)、…、Z_nca(τ′_L-1) all included in the noise power set, this has namely given tacit consent to all of sampled signal and both has been from noise background, therefore, in step 108, by noise power γ_nEstimated valueAs noise power γ_n。

If N > L-1 is (i.e. n_ini+ 1 > L-1) be false, then enter step 107, in step 107, continue to judge Z_nca(τ′_N) > whether S set up, namely judge:Whether set up.If setting up, then it is assumed that sampled signal Z_nca(τ′₀)、…、Z_nca(τ′_nini) from noise background, and sampled signal..., Z_nca(τ′_L-1) it being all from jamming target echo, jamming target echo samples deleted by Long Term Evolution RACH receiver, and enters step 108.In step 108, by noise power γ_nEstimated valueAs noise power γ_n

If Z_nca(τ′_N) > S is false, namelyIt is false, then it is assumed that sampled signal Z_nca(τ′_nini+1) from noise background, and return step 103, in step 103, reset noise power γ_nEstimated value, by noise power γ_nEstimated value be updated to ${\mathrm{\&gamma;}}_n={\mathrm{\&gamma;}}_{n_{\mathrm{ini}}}+Z_{\mathrm{nca}}({\mathrm{\&tau;}}_{n_{\mathrm{ini}}}^{\&prime;}+1),$ And enter step 104.

At step 104, according to z_nca(τ) cumulative distribution function and the mistake probability of erasure P after updating_fcObtain the threshold factor after updating

I.e. basis $F^{\&prime;}\left(T_{n_{\mathrm{ini}}}\right)=1-e^{{-N}_a{N}_{\mathrm{nca}}{T}_{n_{\mathrm{ini}}}}\underset{k=0}{\overset{N_a{N}_{\mathrm{nca}}-1}{\mathrm{\&Sigma;}}}\frac{1}{k!}{\left(N_a{N}_{\mathrm{nca}}{T}_{n_{\mathrm{ini}}}\right)}^k$ And $P_{\mathrm{fc}}=1-F^{\&prime;}\left(T_{n_{\mathrm{ini}}+1}\right),$ Obtain $P_{\mathrm{fc}}=e^{{-N}_a{N}_{\mathrm{nca}}{T}_{n_{\mathrm{ini}}+1}}\underset{k=0}{\overset{N_a{N}_{\mathrm{nca}}-1}{\mathrm{\&Sigma;}}}\frac{1}{k!}{\left(N_a{N}_{\mathrm{nca}}{T}_{n_{\mathrm{ini}}+1}\right)}^k,$ Solve threshold factor againMistake probability of erasure P after renewal_fcWith the front P once obtained_fcRelation be: P_fc(k+1)=P_fc(k) (1-δ), wherein, P_fc(k+1) the mistake probability of erasure after renewal, P it are_fcK () once obtains probability of erasure by mistake for front, the value of δ can set according to the actual requirements.But obtaining one to be mentioned that, δ can take 0, say, that the mistake probability of erasure in present embodiment is also can be changeless.

In step 105, Long Term Evolution RACH receiver is according to the noise power γ after updating_nEstimated value and threshold factor obtain threshold valuesNamely $S=T_{n_{\mathrm{ini}}+1}{\mathrm{\&gamma;}}_n=T_{n_{\mathrm{ini}}+1}({\mathrm{\&gamma;}}_{n_{\mathrm{ini}}}+Z_{\mathrm{nca}}\left({\mathrm{\&tau;}}_{n_{\mathrm{ini}}+1}^{\&prime;}\right)),$ And reenter step 106.

In step 106, N=n is first taken_ini+ 2, then judge N > L-1 (i.e. n_ini+ 2 > L-1) whether set up.Until deleting power time delay spectral sequence { z_nca(τ_i) in all of jamming target echo samples signal, obtain power time delay spectral sequence { z_nca(τ_i) in all sum gathering signals from noise background, and using the described collection signal from noise background and as noise power γ_n。

In step 109, Long Term Evolution RACH receiver obtains noise power threshold factor T_r。

Specifically, Long Term Evolution RACH receiver first obtains the maximum P of the invariable false alerting of signature sequence detection_fa, wherein, described P_faMeet: F (T_det)=1-P_fa(T_det)^L；

Further according to described F (T_det)=1-P_fa(T_det)^L, and in conjunction with z_nca(τ) cumulative distribution function: $F\left(T_{\det }\right)=F^{\&prime;}\left(T_r\right)=1-e^{-N_a{N}_{\mathrm{nca}}{T}_r}\underset{k=0}{\overset{N_a{N}_{\mathrm{nca}}-1}{\mathrm{\&Sigma;}}}\frac{1}{k!}{\left(N_a{N}_{\mathrm{nca}}{T}_r\right)}^k,$

Obtain: $P_{\mathrm{fa}}{\left(T_{\det }\right)}^L=e^{-N_a{N}_{\mathrm{nca}}{T}_r}\underset{k=0}{\overset{N_a{N}_{\mathrm{nca}}-1}{\mathrm{\&Sigma;}}}\frac{1}{k!}{\left(N_a{N}_{\mathrm{nca}}{T}_r\right)}^k,$ Thus obtaining the noise power threshold factor T that the maximum detection probability of signature sequence is corresponding_r。

In step 110, according to noise power γ_nAnd noise power threshold factor T_r, obtain the thresholding T carrying out signature sequence detection_det, and utilize thresholding T_detCarry out peak value searching.

In this step, thresholding T_detFor: T_det=γ_nT_r；Utilize thresholding T_detCarry out the purpose of peak value searching namely judge to receive in signal whether there is up ZC sequence of requests signal, namely the method for its judgement is compare T_detWith z_nca(τ_i) magnitude relationship, if z_nca(τ_i)≥T_det, then it is assumed that z_nca(τ_i) for signature sequence；If z_nca(τ_i)<T_det, then it is assumed that z_nca(τ_i) for noise.

Second embodiment of the invention relates to the signature sequence detection method that a kind of uplink random accesses.Second embodiment is the further improvement done on the basis of the first embodiment, its improvements are at place: in second embodiment of the invention, before the step that will receive signal and be converted to baseband signal, Long Term Evolution RACH receiver has determined whether that signal enters, and is judging have signal to send, after entering, the request carrying out baseband signal conversion.Specifically, before the step that will receive signal and be converted to baseband signal, Long Term Evolution RACH receiver can periodically detect whether that signal enters, and this way is conducive to Long Term Evolution RACH receiver to be translated into baseband signal in time.

Third embodiment of the invention relates to the signature sequence detection method that a kind of uplink random accesses.3rd embodiment and first is implemented roughly the same, and main distinction part is in that: in the first embodiment, and the estimated value of the noise power initially set up is0≤j≤n_ini≤L-1；And in third embodiment of the invention, take n_ini=0, the estimated value of the noise power namely set asThis value mode is for the first embodiment, it is possible to power time delay spectral sequence { z_nca(τ_i) in all sampled signals carry out judgement one by one so that the final noise power obtained is more accurate.

Four embodiment of the invention relates to the signature sequence detecting device that a kind of uplink random accesses, as it is shown on figure 3, comprise: time delay spectral sequence acquisition module, noise power acquisition module, noise power threshold factor acquisition module and signature sequence detection module；

Time delay spectral sequence acquisition module is used for obtaining power time delay spectral sequence { z_nca(τ_i), wherein, 0≤i≤L-1, L represents the largest loop displacement of ZC root sequence, Z_nca(τ_i) represent ith sample signal in power time delay spectral sequence, τ_iCyclic shift corresponding to i-th ZC basic sequence；

Noise power acquisition module is used for deleting power time delay spectral sequence { z_nca(τ_i) in jamming target echo samples signal, sue for peace deleting the remaining sampled signal from noise background in the power time delay spectral sequence after described jamming target echo samples signal, and using obtained and as noise power γ_n；

Noise power threshold factor acquisition module is used for obtaining noise power threshold factor T_r；

Signature sequence detection module is for according to described noise power γ_nAnd noise power threshold factor T_r, obtain the thresholding T carrying out signature sequence detection_det, and utilize described thresholding T_detCarry out peak value searching.

Specifically, noise power acquisition module includes: sorting sub-module, noise power estimation value set submodule, threshold factor obtains submodule, threshold values obtains submodule, judges that submodule takes.

Sorting sub-module is used for the size according to amplitude to described power time delay spectral sequence { z_nca(τ_i) be ranked up, generate new power time delay spectral sequence { z_nca(τ_i'), wherein, Z_nca(τ₀′)、Z_nca(τ₁′)、…、Z_nca(τ′_L-1) amplitude increase successively.

Noise power estimation value sets submodule for according to described new power time delay spectral sequence { z_nca(τ_i'), set noise power γ_nEstimated value beWherein, 0≤j≤n_ini≤L-1。

Threshold factor obtains submodule for according to z_nca(τ) cumulative distribution function, and the mistake probability of erasure P set_fc, obtain threshold factor

Threshold values obtains submodule for according to described noise power γ_nEstimated value and threshold factor, set threshold values $S=T_{n_{\mathrm{ini}}}{\mathrm{\&gamma;}}_{n_{\mathrm{ini}}}.$

Judge that submodule takes N=n_ini+ 1, and judge N > whether L-1 sets up, if establishment, then it is assumed that sampled signal Z_nca(τ₀′)、Z_nca(τ₁′)、…、Z_nca(τ′_L-1) it is all from noise background, and by noise power γ_nEstimated valueAs noise power γ_n；If being false, then continue to judge Z_nca(τ′_N) > whether S set up；

If setting up, then it is assumed that sampled signal Z_nca(τ₀′)、…、From noise background, and sampled signal..., Z_nca(τ′_L-1) it is all from jamming target echo, delete described jamming target echo samples signal, and by noise power γ_nEstimated valueAs noise power γ_n；If being false, then it is assumed that sampled signalFrom noise background, and set submodule and threshold factor acquisition submodule transmission renewal instruction to noise power estimation value；After receiving renewal instruction, noise power estimation value sets submodule by described noise power γ_nEstimated value be updated toThreshold factor obtains submodule according to z_nca(τ) cumulative distribution function and the mistake probability of erasure P after updating_fcObtain the threshold factor after updatingDescribed threshold values obtains submodule according to the noise power γ after updating_nEstimated value and update after threshold factorDetermine the threshold values after renewalJudge that submodule takes N=n again_ini+ 2 judge, until deleting power time delay spectral sequence { z_nca(τ_i) in all of jamming target echo samples signal, obtain power time delay spectral sequence { z_nca(τ_i) in all sum gathering signals from noise background, and using the described collection signal from noise background and as noise power γ_n。

It addition, signature sequence detection module includes: thresholding obtains submodule and peak value searching submodule；

Thresholding obtains submodule for according to described noise power γ_nAnd noise power threshold factor T_r, obtain the thresholding T carrying out signature sequence detection_det, described thresholding T_detFor: T_det=γ_nT_r；

Peak value searching submodule is used for judging described T_detWith z_nca(τ_i) magnitude relationship, and at z_nca(τ_i)≥T_detTime, export z_nca(τ_i) for the judged result of signature sequence；At z_nca(τ_i)<T_detTime, export z_nca(τ_i) for the judged result of noise.

It is seen that, present embodiment is the system embodiment corresponding with the first embodiment, and present embodiment can be worked in coordination enforcement with the first embodiment.The relevant technical details mentioned in first embodiment is still effective in the present embodiment, in order to reduce repetition, repeats no more here.Correspondingly, the relevant technical details mentioned in present embodiment is also applicable in the first embodiment.

It is noted that each module involved in present embodiment is logic module, in actual applications, a logical block can be a physical location, it is also possible to be a part for a physical location, it is also possible to realize with the combination of multiple physical locations.Additionally, for the innovative part highlighting the present invention, do not introduced by the unit less close with solving technical problem relation proposed by the invention in present embodiment, but this is not intended that in present embodiment to be absent from other unit.

Fifth embodiment of the invention relates to the signature sequence detecting device that a kind of uplink random accesses.5th embodiment is the further improvement done on the basis of the 4th embodiment, its improvements are at place: in fifth embodiment of the invention, it is additionally provided with signal detection module, this signal detection module is used for determining whether that signal enters, and is judging have signal to send, after entering, the request carrying out baseband signal conversion.Specifically, receiving before signal is converted to baseband signal, signal detection module can periodically detect whether that signal enters, and this way is conducive to Long Term Evolution RACH receiver in time the signal of entrance to be converted into baseband signal.

Sixth embodiment of the invention relates to the signature sequence detecting device that a kind of uplink random accesses.6th embodiment and the 4th is implemented roughly the same, and main distinction part is in that: in the 4th embodiment, noise power estimation value set the estimated value of the noise power that submodule initially sets up as0≤j≤n_ini≤L-1；And in sixth embodiment of the invention, take n_ini=0, the estimated value of the noise power namely set asThis value mode is for the 4th embodiment, it is possible to power time delay spectral sequence { z_nca(τ_i) in all sampled signals carry out judgement one by one so that the final noise power obtained is more accurate.

It will be understood by those skilled in the art that the respective embodiments described above are to realize specific embodiments of the invention, and in actual applications, it is possible in the form and details it is done various change, without departing from the spirit and scope of the present invention.

Claims (11)

1. the signature sequence detection method that a uplink random accesses, it is characterised in that comprise the steps of

Obtain power time delay spectral sequence { z_nca(τ_i), wherein, 0≤i≤L-1, L represents the largest loop displacement of ZC root sequence, Z_nca(τ_i) represent ith sample signal in power time delay spectral sequence, τ_iCyclic shift corresponding to i-th ZC basic sequence；

Delete power time delay spectral sequence { z_nca(τ_i) in jamming target echo samples signal, sue for peace deleting the remaining sampled signal from noise background in the power time delay spectral sequence after described jamming target echo samples signal, and using obtained and as noise power γ_n；

Obtain noise power threshold factor T_r；

According to described noise power γ_nAnd noise power threshold factor T_r, obtain the thresholding T carrying out signature sequence detection_det, and utilize described thresholding T_detCarry out peak value searching.

2. the signature sequence detection method that uplink random according to claim 1 accesses, it is characterised in that at described deletion power time delay spectral sequence { z_nca(τ_i) in jamming target echo samples signal, sue for peace deleting the remaining sampled signal from noise background in the power time delay spectral sequence after described jamming target echo samples signal, and using obtained and as noise power γ_nStep in, including following sub-step:

According to the size of amplitude to described power time delay spectral sequence { z_nca(τ_i) be ranked up, generate new power time delay spectral sequence { z_nca(τ′_i), wherein, Z_nca(τ′₀)、Z_nca(τ′₁)、…、Z_nca(τ′_L-1) amplitude increase successively；

According to described new power time delay spectral sequence { z_nca(τ′_i), set noise power γ_nEstimated value beWherein, 0≤j≤n_ini≤L-1；

According to z_nca(τ) cumulative distribution function and by mistake probability of erasure P_fc, obtain threshold factorWherein z_nca(τ) be corresponding toStochastic variable, described inSquare representedPower time delay for described ZC sequence is composed；

According to described noise power γ_nEstimated value and threshold factor, set threshold values

Take N=n_ini+ 1, it is judged that N > whether L-1 sets up, if setting up, then it is assumed that sampled signal Z_nca(τ′₀)、Z_nca(τ′₁)、…、Z_nca(τ′_L-1) it is all from noise background, and by noise power γ_nEstimated valueAs noise power γ_n；If being false, then judge Z_nca(τ′_N) > whether S set up；

If setting up, then it is assumed that sampled signalFrom noise background, and sampled signalIt is all from jamming target echo, deletes described jamming target echo samples signal, and by noise power γ_nEstimated valueAs noise power γ_n；If Z_nca(τ′_N) > S is false, then it is assumed that sampled signalFrom noise background, by described noise power γ_nEstimated value be updated toAnd according to z_nca(τ) cumulative distribution function and the mistake probability of erasure P after updating_fcObtain the threshold factor after updatingDetermine revised threshold valuesAnd again take N=n_ini+ 2 judge, until deleting power time delay spectral sequence { z_nca(τ_i) in all of jamming target echo samples signal, obtain power time delay spectral sequence { z_nca(τ_i) in all sum gathering signals from noise background, and using the described collection signal from noise background and as noise power γ_n。

3. the signature sequence detection method that uplink random according to claim 2 accesses, it is characterised in that described according to z_nca(τ) cumulative distribution function and by mistake probability of erasure P_fc, obtain threshold factorStep before, also include following sub-step:

Obtain z_nca(τ) cumulative distribution function, wherein, described z_nca(τ) cumulative distribution function is:

Wherein, N_aFor accepting number of antennas, N_ncaRepeatable block number for ZC sequence；

Obtain probability of erasure P by mistake_fc, wherein said P_fcMeet:。

4. the signature sequence detection method that uplink random according to claim 2 accesses, it is characterised in that described n_ini=0.

5. the signature sequence detection method that uplink random according to claim 1 accesses, it is characterised in that described thresholding T_detFor: T_det=γ_nT_r；

Utilizing described thresholding T_detCarry out in the step of peak value searching, including following sub-step:

Judge described T_detWith z_nca(τ_i) magnitude relationship, if z_nca(τ_i)≥T_det, then z_nca(τ_i) for signature sequence；If z_nca(τ_i)<T_det, then z_nca(τ_i) for noise.

6. the signature sequence detection method that uplink random according to claim 1 accesses, it is characterised in that at described acquisition noise power threshold factor T_rStep in, including following sub-step:

Obtain the maximum P of the invariable false alerting of described signature sequence detection_fa, wherein, described P_faMeet: F (T_det)=1-P_fa(T_det)^L；

According to described F (T_det)=1-P_fa(T_det)^L, and in conjunction with z_nca(τ) cumulative distribution function:Obtain the noise power threshold factor T that the maximum detection probability of signature sequence is corresponding_r。

7. the signature sequence detection method that uplink random according to claim 1 accesses, it is characterised in that in the step of described acquisition power time delay spectral sequence, including following sub-step:

Signal will be received and be converted to baseband signal；

Described baseband signal is carried out linear filtering；

To described carry out linear filtering after baseband signal sample；

Remove the Cyclic Prefix of the baseband signal after described sampling, obtain Baseband Receiver discrete signal y (n) comprising noise；

Described y (n) is carried out frequency domain conversion, subcarrier demapping, and after frequency domain is multiplied with described ZC sequence and passes through spatial transform, applies square-law, obtain ZC sequence power time delay spectrum:DescribedWherein, a is the antenna mark of receiver, and m is the repeatable block number mark of ZC sequence, and τ is corresponding to the cyclic shift of ZC basic sequence, x_uN () is ZC root sequence；

Compose according to described ZC sequence power time delay, obtain described ZC sequence power time delay spectral sequence.

8. the signature sequence detection method that uplink random according to claim 7 accesses, it is characterised in that described by the step receiving signal and being converted to baseband signal before, further comprising the steps of:

Determine whether that signal enters, and judging have signal to send, after entering, the request carrying out baseband signal conversion.

9. the signature sequence detecting device that a uplink random accesses, it is characterised in that comprise: time delay spectral sequence acquisition module, noise power acquisition module, noise power threshold factor acquisition module and signature sequence detection module；

Described time delay spectral sequence acquisition module is used for obtaining power time delay spectral sequence { z_nca(τ_i), wherein, 0≤i≤L-1, L represents the largest loop displacement of ZC root sequence, Z_nca(τ_i) represent ith sample signal in power time delay spectral sequence, τ_iCyclic shift corresponding to i-th ZC basic sequence；

Described noise power acquisition module is used for deleting power time delay spectral sequence { z_nca(τ_i) in jamming target echo samples signal, sue for peace deleting the remaining sampled signal from noise background in the power time delay spectral sequence after described jamming target echo samples signal, and using obtained and as noise power γ_n；

Described noise power threshold factor acquisition module is used for obtaining noise power threshold factor T_r；

Described signature sequence detection module is for according to described noise power γ_nAnd noise power threshold factor T_r, obtain the thresholding T carrying out signature sequence detection_det, and utilize described thresholding T_detCarry out peak value searching.

10. the signature sequence detecting device that uplink random according to claim 9 accesses, it is characterized in that, described noise power acquisition module includes: sorting sub-module, noise power estimation value set submodule, threshold factor obtains submodule, threshold values obtains submodule, judges that submodule takes；

Described sorting sub-module is used for the size according to amplitude to described power time delay spectral sequence { z_nca(τ_i) be ranked up, generate new power time delay spectral sequence { z_nca(τ′_i), wherein, Z_nca(τ′₀)、Z_nca(τ′₁)、…、Z_nca(τ′_L-1) amplitude increase successively；

Described noise power estimation value sets submodule for according to described new power time delay spectral sequence { z_nca(τ′_i), set noise power γ_nEstimated value beWherein, 0≤j≤n_ini≤L-1；

Described threshold factor obtains submodule for according to z_nca(τ) cumulative distribution function, and the mistake probability of erasure P set_fc, obtain threshold factor

Described threshold values obtains submodule for according to described noise power γ_nEstimated value and threshold factor, set threshold values

Described judgement submodule takes N=n_ini+ 1, and judge N > whether L-1 sets up, if establishment, then it is assumed that sampled signal Z_nca(τ′₀)、Z_nca(τ′₁)、…、Z_nca(τ′_L-1) it is all from noise background, and by noise power γ_nEstimated valueAs noise power γ_n；If being false, then continue to judge Z_nca(τ′_N) > whether S set up；

If setting up, then it is assumed that sampled signalFrom noise background, and sampled signalIt is all from jamming target echo, deletes described jamming target echo samples signal, and by noise power γ_nEstimated valueAs noise power γ_n；If being false, then it is assumed that sampled signalFrom noise background, and set submodule and threshold factor acquisition submodule transmission renewal instruction to described noise power estimation value；After receiving described renewal instruction, described noise power estimation value sets submodule by described noise power γ_nEstimated value be updated toDescribed threshold factor obtains submodule according to z_nca(τ) cumulative distribution function and the mistake probability of erasure P after updating_fcObtain the threshold factor after updatingDescribed threshold values obtains submodule according to the noise power γ after updating_nEstimated value and update after threshold factorDetermine revised threshold valuesDescribed judgement submodule takes N=n again_ini+ 2 judge, until deleting power time delay spectral sequence { z_nca(τ_i) in all of jamming target echo samples signal, obtain power time delay spectral sequence { z_nca(τ_i) in all sum gathering signals from noise background, and using the described collection signal from noise background and as noise power γ_n。

11. the signature sequence detecting device that uplink random according to claim 9 accesses, it is characterised in that described signature sequence detection module includes: thresholding obtains submodule and peak value searching submodule；

Described thresholding obtains submodule for according to described noise power γ_nAnd noise power threshold factor T_r, obtain the thresholding T carrying out signature sequence detection_det, described thresholding T_detFor: T_det=γ_nT_r；

Described peak value searching submodule is used for judging described T_detWith z_nca(τ_i) magnitude relationship, and at z_nca(τ_i)≥T_detTime, export z_nca(τ_i) for the judged result of signature sequence；At z_nca(τ_i)<T_detTime, export z_nca(τ_i) for the judged result of noise.