CN103900682A - Time-frequency joint-type signal fluctuation alignment detection method and system - Google Patents

Abstract

The invention relates to a time-frequency joint-type signal fluctuation alignment detection method. The method comprises steps of carrying out time-frequency adaptive noise cancellation processing on received original signals to obtain time domain filtering output signals, carrying out orthogonal analytical transformation on the time domain filtering output signals to obtain complex analytical signals, calculating an instantaneous characteristic value in the complex analytical signals and using the calculated instantaneous characteristic value to represent the complex analytical signals, carrying out fluctuation correlation processing on the instantaneous characteristic value to obtain fluctuation interference factor, and using the fluctuation interference factor to replace characteristic parameters of complex analytical signals represented by the instantaneous characteristic value to obtain signals of alignment compensation processing on fluctuation phase. According to the method and the system, due to introduction of adaptive filtering, the fact that the time correlation radius of periodic target signals is far greater than that of broadband interference noise is effectively made use of, and detection performances of weak targets in low input signal to noise ratio condition can be improved.

Description

A kind of time-frequency combination formula signal fluctuation alignment detection method and system

Technical field

The present invention relates to field of underwater acoustic signal processing, particularly a kind of time domain combined formula signal fluctuation alignment detection method and system.

Background technology

UNDERWATER ACOUSTIC SIGNAL DETECTION processing is one of direction of enlivening the most of current demand signal and field of information processing, in the military civil areas such as communication under water, remote measurement, remote control, underawater ordnance and ocean development, has important application.Ocean examination, Underwater resources are developed, are helped fishing, collision prevention, navigation and even ocean and general circulation purpose monitoring etc. all directly or indirectly to use hydrospace detection technology; And detection, location and the identification of Sonar system to Ship Target, the Remote to underawater ordnance and remote measurement, and liaison and data transmission etc. between Ship Target all will detect the feeble signal arriving in powerful ambient sea noise.

But due to reasons such as sound source self character, multipath interference, wave and ocean temperature microstructures, make ocean surface can often present wave, gush or the out-of-flatness of ripples and so on, this out-of-flatness surface makes sound wave in the reflection on sea, introduce random reflected or diffuse reflection composition, thereby cause that the acoustical signal of propagating in Seawater is always full of fluctuating in amplitude and phase place, and big rise and fall is also very fast.Underwater Signal Detection of the prior art is not all considered the impact that the fluctuation effect of this target radiated noise and background is brought to target echo detection.

Summary of the invention

The object of the invention is to overcome Underwater Signal Detection of the prior art and do not consider the defect of the impact that the fluctuation effect of target radiated noise and background brings to target echo detection, can strengthen at the Underwater Signal Detection of the target recognition capability under the channel of uncertain ocean that rises and falls thereby provide a kind of.

To achieve these goals, the invention provides a kind of time domain combined formula signal fluctuation alignment detection method, comprising:

Step 1), received original signal is carried out to the processing of time-domain adaptive noise cancellation, obtain time-domain filtering output signal;

Step 2), to step 1) the time-domain filtering output signal that obtains does orthogonal analytic trnasformation, obtains complex analytic signal;

Step 3), from step 2) ask for instantaneous characteristic quantity the complex analytic signal that obtains, utilize the instantaneous characteristic quantity of asking for to represent step 2) complex analytic signal that obtains;

Step 4), to step 3) the instantaneous characteristic quantity that obtains does fluctuating relevant treatment, obtains the interference factor that rises and falls;

Step 5), utilize step 4) the fluctuating interference factor alternative steps 3 that obtains) characteristic parameter in the complex analytic signal that represents of the instantaneous characteristic quantity of use that obtains, obtain fluctuating phase place to do the signal of alignment compensation processing.

In technique scheme, also comprise:

Step 6), calculation procedure 5) output power of the signal that obtains.

In technique scheme, described step 1) comprising:

Step 1-1), to received original signal do decorrelation postpone;

Step 1-2), to through decorrelation postpone signal do auto adapted filtering, obtain time-domain filtering output signal.

In technique scheme, described auto adapted filtering adopts sef-adapting filter through repeatedly iteration realization, repeatedly regulating described sef-adapting filter in iterative process, makes error signal (t) minimum; In the time that described error signal (t) reaches minimal value, the result that filtering obtains is time-domain filtering output signal; Wherein,

ε(t)＝n(t)+Acos(2πf ₀t+θ _in)-[n′(t)+Bcos(2πf ₀t+θ _out)]

N (t) represents the broadband noise in original signal, and A represents the range weight of line spectrum signal, f ₀for the centre frequency of line spectrum signal, θ _inrepresent the initial phase of line spectrum signal, n ' (t) represents the broadband noise that comprises in the original signal result after time-domain filtering, and B represents the range weight after time-domain filtering is exported, θ _outrepresent the output phase of time-domain filtering line spectrum signal.

In technique scheme, in described step 3) in, instantaneous characteristic quantity comprises instantaneous envelope and instantaneous phase; Described step 3) comprising:

Step 3-1), calculate the instantaneous envelope of complex analytic signal;

Adopt B (t) to represent the instantaneous envelope of complex analytic signal z (t), account form is as follows:

$B\left(t\right)=\sqrt{{\mathrm{Re}}^2\left[z\left(t\right)\right]+{\mathrm{Im}}^2\left[z\left(t\right)\right]}$

$=\sqrt{y^2\left(t\right)+H^2\left[y\left(t\right)\right]}$

Wherein, y (t) represents time-domain filtering output signal;

Step 3-2), calculate the instantaneous phase of complex analytic signal;

Adopt

the instantaneous phase that represents complex analytic signal z (t), account form is as follows:

$\widetilde{\mathrm{\Θ}}\left(t\right)=\arctan \left\{\frac{\mathrm{Im}\left[z\left(t\right)\right]}{\mathrm{Re}\left[z\left(t\right)\right]}\right\}=\arctan \left\{\frac{H\left[x\left(t\right)\right]}{x\left(t\right)}\right\}$

Wherein x (t) represents original signal;

Step 3-3), utilize described instantaneous envelope and instantaneous phase to represent complex analytic signal;

The polar coordinate representation form of described complex analytic signal z (t) is:

$z\left(t\right)=B\left(t\right)\·e^{j\widetilde{\mathrm{\Θ}}\left(t\right)}=B\left(t\right)\cos \widetilde{\mathrm{\Θ}}\left(t\right)+\mathrm{jB}\left(t\right)\sin \widetilde{\mathrm{\Θ}}\left(t\right).$

In technique scheme, described fluctuating interference factor passes through described instantaneous phase

do fluctuating relevant treatment and obtain, described fluctuating interference factor be expressed as:

$\widetilde{\mathrm{\Ψ}}\left(t_i\right)=\widetilde{\mathrm{\Θ}}\left(t_i\right)-2\widetilde{\mathrm{\Θ}}\left(t_{i-1}\right)+\widetilde{\mathrm{\Θ}}\left(t_{i-2}\right).$

In technique scheme, in described step 5) in, fluctuating interference factor utilized

alternative steps 3) the complex analytic signal z (t that represents of the instantaneous characteristic quantity of use that obtains _i) in characteristic parameter

obtain fluctuating phase place to be the signal z ' (t of alignment compensation processing _i);

$z^{\′}\left(t_i\right)=B\left(t_i\right)\cos \left[\widetilde{\mathrm{\Ψ}}\left(t_i\right)\right]+\mathrm{jB}\left(t_i\right)\sin \left[\widetilde{\mathrm{\Ψ}}\left(t_i\right)\right]=B\left(t_i\right)e^{j\widetilde{\mathrm{\Ψ}}\left(t_i\right)}.$

The present invention also provides a kind of time domain combined formula signal fluctuation alignment detection system, comprising: auto adapted filtering module, orthogonal analytic trnasformation module, ask for instantaneous characteristic quantity module, fluctuating interference factor computing module, alignment compensation module; Wherein,

Described auto adapted filtering module, for received original signal is carried out to the processing of time-domain adaptive noise cancellation, obtains time-domain filtering output signal;

Described orthogonal analytic trnasformation module is done orthogonal analytic trnasformation for the time-domain filtering output signal that auto adapted filtering module is obtained, and obtains complex analytic signal;

The described instantaneous characteristic quantity module of asking for is asked for instantaneous characteristic quantity for the complex analytic signal obtaining from described orthogonal analytic trnasformation module, utilizes the instantaneous characteristic quantity of asking for to represent the complex analytic signal that described orthogonal analytic trnasformation module obtains;

Described fluctuating interference factor computing module, for asking for the instantaneous characteristic quantity that instantaneous characteristic quantity module obtains and do fluctuating relevant treatment described, obtains the interference factor that rises and falls;

Described alignment compensation module utilizes fluctuating interference factor that described fluctuating interference factor computing module obtains to ask for the characteristic parameter in the complex analytic signal that the instantaneous characteristic quantity of use that instantaneous characteristic quantity module obtains represents described in substituting, and obtains fluctuating phase place to do the signal of alignment compensation processing.

In technique scheme, also comprise output power calculating module;

Described output power is calculated the output power of module for the signal that calculates alignment compensation module and obtain.

The invention has the advantages that:

1, the present invention is by introducing auto adapted filtering thought, effectively utilize the time correlation radius of target cycle signal much larger than the time correlation radius of broadband interference noise, obtain a kind ofly effectively suppressing noise and adaptive targets by narrow band signal strengthens system, improved the detection performance of weak target under low input signal-to-noise ratio condition.

2, the present invention is by effectively extracting receiving target signal and the phase drift difference of broadband noise under fluctuating channel effects, phase shift homogeneity further combined with the phase shift homogeneity of line spectrum signal much larger than noise, realize a kind of frequency domain phase coherent signal disposal system, effectively strengthened in the target recognition capability rising and falling under the channel of uncertain ocean.

Accompanying drawing explanation

Fig. 1 is the schematic diagram of time domain combined formula signal fluctuation alignment detection method of the present invention;

Fig. 2 is the phase difference alignment result schematic diagram of the actual line spectrum signal recording at China South Sea;

Fig. 3 is the phase difference alignment result schematic diagram in the actual noise recording in China South Sea;

Fig. 4 is that complex plane polar axis shaft rotary difference is processed schematic diagram;

Fig. 5 is the detection results of property comparison diagram of time-frequency combination formula fluctuating detection method of the present invention and prior art;

Fig. 6 is the schematic diagram of thinking conceivable simulate signal alignment compensation comparative result according to phase rotating difference under complex coordinates axle.

Embodiment

Now the invention will be further described by reference to the accompanying drawings.

With reference to figure 1, method of the present invention comprises the following steps:

Step 1), received original signal is carried out to the processing of time-domain adaptive noise cancellation.

This step specifically comprises:

Step 1-1), to received original signal do decorrelation postpone.

In this step, suppose that original signal is made up of broadband noise and line spectrum signal, its expression formula is:

x(t)＝Acos(2πf ₀t+θ _in)+n(t)

Wherein, A represents the range weight of line spectrum signal, f ₀for the centre frequency of line spectrum signal, θ _infor the initial phase of line spectrum signal.N (t) represents the broadband noise in original signal.

The time that described decorrelation postpones is Δ.

Step 1-2), to through decorrelation postpone signal do auto adapted filtering, obtain time-domain filtering output signal, thereby realize time-domain adaptive noise cancellation.

In this step, the signal postponing through decorrelation being done to auto adapted filtering adopts sef-adapting filter to realize.Described auto adapted filtering need to do repeatedly iteration associative operation.In the process of iteration associative operation repeatedly, should regulate sef-adapting filter, make error signal (t) minimum.In the time that error signal (t) reaches minimal value, the result that filtering obtains is time-domain filtering output signal.

Suppose that time-domain filtering output signal is y (t)=Bcos (2 π f ₀t+ θ _out(t), wherein B is the range weight after time-domain filtering output to)+n ', θ _outfor the output phase (being also the instantaneous phase of actual line spectral component) of time-domain filtering line spectrum signal, the expression formula of error signal (t) is as follows:

ε(t)＝n(t)+Acos(2πf ₀t+θ _in)-[n′(t)+Bcos(2πf ₀t+θ _out)]

Because noise itself and signal are irrelevant, and n (t) and n (t-Δ) are irrelevant, thus n (t) and n ' (t) (n ' (t) represents the broadband noise that comprises in the original signal result after time-domain filtering) irrelevant.So:

E(ε ²(t))＝E(n ²(t))+E(n′ ²(t))

+E[Acos(2πf ₀t+θ _in)-Bcos(2πf ₀t+θ _out)] ²

In above formula, E (n ²(t)) be a constant, irrelevant with auto adapted filtering.Make E (ε ²(t)) minimumly to make exactly the Section 2 value in above formula minimum.By regulating sef-adapting filter, can make by the instantaneous phase θ of the actual line spectral component of noise _outwith former instantaneous phase θ _inbe tending towards equal, thereby the Section 2 of above formula is zero.Certainly now E (n ' ²(t)) may not be certain minimum, but the end product that auto adapted filtering counteracting regulates makes the middle n ' of time-domain signal output y (t), (t) mean square deviation is as far as possible little, and actual line spectral component Bcos (2 π f ₀t+ θ _outapproach original signal Acos (2 π f as far as possible ₀t+ θ _inthereby, make the SNR signal to noise ratio (S/N ratio) in y (t) reach very big.

Step 2), to step 1) the time-domain filtering output signal that obtains does orthogonal analytic trnasformation, obtains complex analytic signal.

In the process of time-domain filtering output signal being done to orthogonal analytic trnasformation, introduce complex plane signal z (t), this signal is called to the analytic representation (therefore z (t) also can be called as complex analytic signal) of time-domain filtering output signal y (t).Setting conversion impulse function is

complex plane signal z (t) can be expressed as:

$z\left(t\right)=y\left(t\right)+y\left(t\right)*\widetilde{h\left(t\right)}$

In formula, symbol * represents convolution, according to software radio orthogonal transformation theory, impulse function can try to achieve

$h\left(t\right)=\mathrm{<figure-callout\; id="1"\; label="j"\; filenames="HDA00002659753000021.png"\; state="\{\{state\}\}">j</figure-callout>}\frac{1}{\mathrm{\&pi;t}}$

So above formula can be rewritten as

$z\left(t\right)=y\left(t\right)+\mathrm{<figure-callout\; id="1"\; label="j"\; filenames="HDA00002659753000021.png"\; state="\{\{state\}\}">j</figure-callout>}\frac{1}{\mathrm{\&pi;}}{\&Integral;}_{-\&infin;}^{\&infin;}\frac{y\left(\mathrm{\&tau;}\right)}{t-\mathrm{\&tau;}}\mathrm{d\&tau;}$

Order $\tilde{H}\left[y\left(t\right)\right]=\frac{1}{\mathrm{\&pi;}}{\&Integral;}_{-\&infin;}^{\&infin;}\frac{y\left(\mathrm{\&tau;}\right)}{t-\mathrm{\&tau;}}\mathrm{d\&tau;}$

Have $z\left(t\right)=y\left(t\right)+j\tilde{H}\left[y\left(t\right)\right]$

Now, z (t) is called to the orthogonal analytic representation of time-domain filtering output signal y (t).The real part of z (t) is called to the in-phase component of y (t), and the imaginary part of z (t) is called to the quadrature component of y (t) simultaneously.

Step 3), from step 2) ask for instantaneous characteristic quantity the signal that obtains, utilize the instantaneous characteristic quantity of asking for to represent step 2) complex analytic signal that obtains.

Instantaneous characteristic quantity related in this step comprises instantaneous envelope and instantaneous phase, and the instantaneous envelope that represents z (t) with B (t), is provided by following formula:

$B\left(t\right)=\sqrt{{\mathrm{Re}}^2\left[z\left(t\right)\right]+{\mathrm{Im}}^2\left[z\left(t\right)\right]}$

$=\sqrt{y^2\left(t\right)+H^2\left[y\left(t\right)\right]}$

With

the instantaneous phase that represents z (t), is provided by following formula:

$\widetilde{\mathrm{\&Theta;}}\left(t\right)=\arctan \left\{\frac{\mathrm{Im}\left[z\left(t\right)\right]}{\mathrm{Re}\left[z\left(t\right)\right]}\right\}=\arctan \left\{\frac{H\left[x\left(t\right)\right]}{x\left(t\right)}\right\}$

To sum up obtain the polar coordinate representation form of complex analytic signal z (t):

$z\left(t\right)=B\left(t\right)\&CenterDot;e^{j\widetilde{\mathrm{\&Theta;}}\left(t\right)}=B\left(t\right)\cos \widetilde{\mathrm{\&Theta;}}\left(t\right)+\mathrm{jB}\left(t\right)\sin \widetilde{\mathrm{\&Theta;}}\left(t\right)$

Step 4), to step 3) the instantaneous phase component that obtains does fluctuating relevant treatment, obtains the interference factor that rises and falls.

Accompanying drawing 2 and accompanying drawing 3 is the actual line spectrum signal the recording result of aliging with the phase difference of noise at China South Sea.Can be found out by (b) in Fig. 2: along with the variation of sampling instant, the instantaneous phase of complex signal vector z (t)

there is a kind of phase deviation phenomenon of fixing rate of change, and this fluctuation can be analogous in time scale the linear distribution situation that contains " intrinsic slope ".According to this special status, the present invention adopts a kind of phase difference registration process method based on the rotational transform of complex coordinates axle.

Setting skew phase rotating angular speed is

represent instantaneous phase " linear gradient " on time shaft.The phase angle shift rate at neighbouring sample interval is in section sampling interval, the phasing degree of two continuous sampling samples under same given frequency

with

determine, so obtain instantaneous skew phasing degree speed be:

$\widetilde{\mathrm{\&omega;}}\left(t_i\right)\text{=}\frac{\widetilde{\mathrm{\&Theta;}}\left(t_i\right)-\widetilde{\mathrm{\&Theta;}}\left(t_{i-1}\right)}{t_i-t_{i-1}}$

Because should " slope " tend towards stability, so obtain:

$\widetilde{\mathrm{\&omega;}}\left(t_i\right)=\widetilde{\mathrm{\&omega;}}\left(t_{i-1}\right)\&ap;\widetilde{\mathrm{\&omega;}}\left(t\right)=\frac{d\widetilde{\mathrm{\&Theta;}}\left(t\right)}{\mathrm{dt}}$

Definition sampling instant t _i, instantaneous skew Phase Parameter

as shown in Figure 4.Again because sampling time interval:

T _i-t _i-1=t _i-1-t _i-2=Δ t=constant

Simultaneous above formula can be offset phase mass Φ (t _i) and Φ (t _i-1) equate.Suppose complex signal vector z (t _i) the fluctuating interference volume that brought by uncertain Underwater Acoustic Environment is can obtain so:

$\mathrm{\&Phi;}\left(t_i\right)=[\widetilde{\mathrm{\&Theta;}}\left(t_i\right)-\widetilde{\mathrm{\&Psi;}}\left(t_i\right)]-\widetilde{\mathrm{\&Theta;}}\left(t_{i-1}\right)=\widetilde{\mathrm{\&Theta;}}\left(t_{i-1}\right)-\widetilde{\mathrm{\&Theta;}}\left(t_{i-2}\right)=\mathrm{\&Phi;}\left(t_{i-1}\right)$

So fluctuating interference factor

can be expressed as:

$\widetilde{\mathrm{\&Psi;}}\left(t_i\right)=\widetilde{\mathrm{\&Theta;}}\left(t_i\right)-2\widetilde{\mathrm{\&Theta;}}\left(t_{i-1}\right)+\widetilde{\mathrm{\&Theta;}}\left(t_{i-2}\right)$

Step 5), utilize step 4) the fluctuating interference factor that obtains

alternative steps 3) the complex analytic signal z (t that represents of the instantaneous characteristic quantity of use that obtains _i) in characteristic parameter

obtain new signal phasor z ' (t _i), thereby complete the alignment compensation processing of fluctuating phase place to received signal.

The applicant finds: fluctuating interference factor is because line spectrum component signal has stable phase coherent characteristics, so it is substantially fixing to be subject to the phase change rate that rises and falls after disturbing, so this parameter of definable is the alignment compensation factor.And for radiated noise signals, compensating factor

stochastic distribution, as shown in Figure 3.By accumulative total relevant treatment, energy is cancelled out each other, rather than same superimposed in relevant summation process of line spectrum signal energy, then realized system-gain, can attenuated signal processing procedure in the adverse effect brought of time correlation.

By which, postrotational acoustic pressure set of vectors { z ' (t _i) on the positive half-plane (referring to accompanying drawing 4) of X '-jY ', obtain registration process.This vector z ' (t _i) as follows:

$z^{\&prime;}\left(t_i\right)=B\left(t_i\right)\cos \left[\widetilde{\mathrm{\&Psi;}}\left(t_i\right)\right]+\mathrm{jB}\left(t_i\right)\sin \left[\widetilde{\mathrm{\&Psi;}}\left(t_i\right)\right]=B\left(t_i\right)e^{j\widetilde{\mathrm{\&Psi;}}\left(t_i\right)}$

Set { B (t _i) be signal phasor z ' (t _i) instantaneous amplitude envelope.

It is more than the description to time-frequency combination formula signal fluctuation alignment detection method of the present invention.

In another embodiment, method of the present invention also comprises:

Step 6), calculation procedure 5) output power of the signal that obtains.

$\mathrm{TF}\_\mathrm{CFA}\left\{z^{\&prime;}(B,\widetilde{\mathrm{\&Psi;}})\right\}={\left\{\mathrm{Re}\right[\frac{{\mathrm{\&Sigma;}}_i^N{z}^{\&prime;}\left(t_i\right)}{N}\left]\right\}}^2+{\left\{\mathrm{Im}\right[\frac{{\mathrm{\&Sigma;}}_i^N{z}^{\&prime;}\left(t_i\right)}{N}\left]\right\}}^2$

$={\left\{\frac{{\mathrm{\&Sigma;}}_i^{N}B\left(t_i\right)\cos \left[\widetilde{\mathrm{\&Psi;}}\left(t_i\right)\right]}{N}\right\}}^2+{\left\{\frac{{\mathrm{\&Sigma;}}_i^{N}B\left(t_i\right)\sin \left[\widetilde{\mathrm{\&Psi;}}\left(t_i\right)\right]}{N}\right\}}^2$

Wherein N represents the summation of the time slice experiencing between whole sampling period, and i represents one section of sampling fragment wherein." Re " and " Im " is vector z ' (t after rotation _i) real part and imaginary part.

The present invention also provides a kind of time domain combined formula signal fluctuation alignment detection system, comprising: auto adapted filtering module, orthogonal analytic trnasformation module, ask for instantaneous characteristic quantity module, fluctuating interference factor computing module, alignment compensation module; Wherein,

Described auto adapted filtering module, for received original signal is carried out to the processing of time-domain adaptive noise cancellation, obtains time-domain filtering output signal;

Described orthogonal analytic trnasformation module is done orthogonal analytic trnasformation for the time-domain filtering output signal that auto adapted filtering module is obtained, and obtains complex analytic signal;

The described instantaneous characteristic quantity module of asking for is asked for instantaneous characteristic quantity for the complex analytic signal obtaining from described orthogonal analytic trnasformation module, utilizes the instantaneous characteristic quantity of asking for to represent the complex analytic signal that described orthogonal analytic trnasformation module obtains;

Described fluctuating interference factor computing module, for asking for the instantaneous characteristic quantity that instantaneous characteristic quantity module obtains and do fluctuating relevant treatment described, obtains the interference factor that rises and falls;

Described alignment compensation module utilizes fluctuating interference factor that described fluctuating interference factor computing module obtains to ask for the characteristic parameter in the complex analytic signal that the instantaneous characteristic quantity of use that instantaneous characteristic quantity module obtains represents described in substituting, and obtains fluctuating phase place to do the signal of alignment compensation processing.

In another embodiment, system of the present invention also comprises that output power calculates module, and this module is for calculating the output power of the signal that alignment compensation module obtains.

Method and system of the present invention has good effect.

Fig. 5, for take simulated target signal wire spectral component as detecting sample, adopts the detection performance comparison figure of time-frequency combination signal fluctuation alignment detection method of the present invention and prior art.As we can see from the figure, the detection signal-to-noise ratio gain that time-domain signal strengthens the two kinds of processing modes of aliging with frequency domain fluctuating is all obviously better than traditional energy detection method, and the handling property of time-frequency combination formula signal fluctuation detection method that combines the two technical characterstic is more good on this basis, extract field realistic meaning in clarification of objective far-reaching.

Fig. 6 is for to think conceivable simulate signal alignment compensation comparative result according to phase rotating difference under complex coordinates axle.Due to the uncertain fluctuation effect of sound field, near the instantaneous phase of figure center line spectrum signal fluctuating quantity in time 100 degree is larger, phase compensating factor after registration process " is amassed wealth by heavy taxation " near 0 phase shaft and fluctuating quantity has also obtained alleviation, thereby reaches the inhibition to the uncertain drift of signal phase.

It should be noted last that, above embodiment is only unrestricted in order to technical scheme of the present invention to be described.Although the present invention is had been described in detail with reference to embodiment, those of ordinary skill in the art is to be understood that, technical scheme of the present invention is modified or is equal to replacement, do not depart from the spirit and scope of technical solution of the present invention, it all should be encompassed in the middle of claim scope of the present invention.

Claims (9)

1. a time domain combined formula signal fluctuation alignment detection method, comprising:

Step 1), received original signal is carried out to the processing of time-domain adaptive noise cancellation, obtain time-domain filtering output signal;

Step 2), to step 1) the time-domain filtering output signal that obtains does orthogonal analytic trnasformation, obtains complex analytic signal;

Step 3), from step 2) ask for instantaneous characteristic quantity the complex analytic signal that obtains, utilize the instantaneous characteristic quantity of asking for to represent step 2) complex analytic signal that obtains;

Step 4), to step 3) the instantaneous characteristic quantity that obtains does fluctuating relevant treatment, obtains the interference factor that rises and falls;

Step 5), utilize step 4) the fluctuating interference factor alternative steps 3 that obtains) characteristic parameter in the complex analytic signal that represents of the instantaneous characteristic quantity of use that obtains, obtain fluctuating phase place to do the signal of alignment compensation processing.

2. time domain combined formula signal fluctuation alignment detection method according to claim 1, is characterized in that, also comprises:

Step 6), calculation procedure 5) output power of the signal that obtains.

3. time domain combined formula signal fluctuation alignment detection method according to claim 1 and 2, is characterized in that described step 1) comprising:

Step 1-1), to received original signal do decorrelation postpone;

Step 1-2), to through decorrelation postpone signal do auto adapted filtering, obtain time-domain filtering output signal.

4. time domain combined formula signal fluctuation alignment detection method according to claim 3, it is characterized in that, described auto adapted filtering adopts sef-adapting filter through repeatedly iteration realization, repeatedly regulating described sef-adapting filter in iterative process, makes error signal (t) minimum; In the time that described error signal (t) reaches minimal value, the result that filtering obtains is time-domain filtering output signal; Wherein,

ε(t)＝n(t)+Acos(2πf ₀t+θ _in)-[n′(t)+Bcos(2πf ₀t+θ _out)]

N (t) represents the broadband noise in original signal, and A represents the range weight of line spectrum signal, f ₀for the centre frequency of line spectrum signal, θ _inrepresent the initial phase of line spectrum signal, n ' (t) represents the broadband noise that comprises in the original signal result after time-domain filtering, and B represents the range weight after time-domain filtering is exported, θ _outrepresent the output phase of time-domain filtering line spectrum signal.

5. time domain combined formula signal fluctuation alignment detection method according to claim 1 and 2, is characterized in that, in described step 3) in, instantaneous characteristic quantity comprises instantaneous envelope and instantaneous phase; Described step 3) comprising:

Step 3-1), calculate the instantaneous envelope of complex analytic signal;

Adopt B (t) to represent the instantaneous envelope of complex analytic signal z (t), account form is as follows:

$B\left(t\right)=\sqrt{{\mathrm{Re}}^2\left[z\left(t\right)\right]+{\mathrm{Im}}^2\left[z\left(t\right)\right]}$

$=\sqrt{y^2\left(t\right)+H^2\left[y\left(t\right)\right]}$

Wherein, y (t) represents time-domain filtering output signal;

Step 3-2), calculate the instantaneous phase of complex analytic signal;

Adopt

the instantaneous phase that represents complex analytic signal z (t), account form is as follows:

$\widetilde{\mathrm{\&Theta;}}\left(t\right)=\arctan \left\{\frac{\mathrm{Im}\left[z\left(t\right)\right]}{\mathrm{Re}\left[z\left(t\right)\right]}\right\}=\arctan \left\{\frac{H\left[x\left(t\right)\right]}{x\left(t\right)}\right\}$

Wherein x (t) represents original signal;

Step 3-3), utilize described instantaneous envelope and instantaneous phase to represent complex analytic signal;

The polar coordinate representation form of described complex analytic signal z (t) is:

$z\left(t\right)=B\left(t\right)\&CenterDot;e^{j\widetilde{\mathrm{\&Theta;}}\left(t\right)}=B\left(t\right)\cos \widetilde{\mathrm{\&Theta;}}\left(t\right)+\mathrm{jB}\left(t\right)\sin \widetilde{\mathrm{\&Theta;}}\left(t\right).$

6. time domain combined formula signal fluctuation alignment detection method according to claim 5, is characterized in that, described fluctuating interference factor passes through described instantaneous phase

do fluctuating relevant treatment and obtain, described fluctuating interference factor

be expressed as:

$\widetilde{\mathrm{\&Psi;}}\left(t_i\right)=\widetilde{\mathrm{\&Theta;}}\left(t_i\right)-2\widetilde{\mathrm{\&Theta;}}\left(t_{i-1}\right)+\widetilde{\mathrm{\&Theta;}}\left(t_{i-2}\right).$

7. time domain combined formula signal fluctuation alignment detection method according to claim 6, is characterized in that, in described step 5) in, fluctuating interference factor utilized

alternative steps 3) the complex analytic signal z (t that represents of the instantaneous characteristic quantity of use that obtains _i) in characteristic parameter

obtain fluctuating phase place to be the signal z ' (t of alignment compensation processing _i);

$z^{\&prime;}\left(t_i\right)=B\left(t_i\right)\cos \left[\widetilde{\mathrm{\&Psi;}}\left(t_i\right)\right]+\mathrm{jB}\left(t_i\right)\sin \left[\widetilde{\mathrm{\&Psi;}}\left(t_i\right)\right]=B\left(t_i\right)e^{j\widetilde{\mathrm{\&Psi;}}\left(t_i\right)}.$

8. a time domain combined formula signal fluctuation alignment detection system, is characterized in that, comprising: auto adapted filtering module, orthogonal analytic trnasformation module, ask for instantaneous characteristic quantity module, fluctuating interference factor computing module, alignment compensation module; Wherein,

Described auto adapted filtering module, for received original signal is carried out to the processing of time-domain adaptive noise cancellation, obtains time-domain filtering output signal;

Described orthogonal analytic trnasformation module is done orthogonal analytic trnasformation for the time-domain filtering output signal that auto adapted filtering module is obtained, and obtains complex analytic signal;

The described instantaneous characteristic quantity module of asking for is asked for instantaneous characteristic quantity for the complex analytic signal obtaining from described orthogonal analytic trnasformation module, utilizes the instantaneous characteristic quantity of asking for to represent the complex analytic signal that described orthogonal analytic trnasformation module obtains;

Described fluctuating interference factor computing module, for asking for the instantaneous characteristic quantity that instantaneous characteristic quantity module obtains and do fluctuating relevant treatment described, obtains the interference factor that rises and falls;

Described alignment compensation module utilizes fluctuating interference factor that described fluctuating interference factor computing module obtains to ask for the characteristic parameter in the complex analytic signal that the instantaneous characteristic quantity of use that instantaneous characteristic quantity module obtains represents described in substituting, and obtains fluctuating phase place to do the signal of alignment compensation processing.

9. time domain combined formula signal fluctuation alignment detection system according to claim 8, is characterized in that, also comprises output power calculating module;

Described output power is calculated the output power of module for the signal that calculates alignment compensation module and obtain.

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