CN103634245B - Signal bandwidth estimation method and signal bandwidth estimation device - Google Patents
Signal bandwidth estimation method and signal bandwidth estimation device Download PDFInfo
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Abstract
An embodiment of the invention discloses a signal bandwidth estimation method and a signal bandwidth estimation device. The signal bandwidth estimation method includes performing N-class Welch transform to received signals, particularly, performing rough estimation to bandwidth according to the previous-class Welch transform to adjust the window length of the window function of the current Welch transform so as to acquire a power spectrum of the N-class Welch transform, modifying the power spectrum according to the maximum value thereof, performing point-to-point difference to the modified power spectrum, determining the maximum value point and the minimum value point of the difference results, and finally obtaining the signal bandwidth estimated value according to the maximum value point and the minimum value point of the difference results. By the signal bandwidth estimation method and the signal bandwidth estimation device, the bandwidth estimation precision is increased.
Description
Technical field
The present invention relates to technical field of radio, more particularly, to a kind of signal bandwidth method of estimation and device.
Background technology
In technical field of radio, when a lot of signals may be had to simultaneously enter signal receiver, and the modulation methods of signal
Formula, amount of bandwidth all may be different, although then have received signal, the amount of bandwidth of the signal of unknown reception, modulation type,
The information such as carrier frequency.Accordingly, it would be desirable to the signal receiving is carried out estimation draw the respective bandwidth of signal, thus subsequently signal is entered
Line parameter estimation, Modulation Identification, demodulation etc. are processed.
Common band width estimation method includes mean square root method (root mean square method, rmsm), auto-correlation
Method, maximum entropy method (MEM) (maximum entropy method, mem) and energy concentric method (energy integration
Method, eim) etc..These methods above-mentioned typically directly carry out bandwidth estimation according to the power spectrum of signal, due to power spectrum originally
The fluctuation ratio of body is more violent, and burr is more, often leads to the decline of estimated accuracy.
Content of the invention
The purpose of the embodiment of the present invention is to provide a kind of signal bandwidth method of estimation and device, improves the essence estimating bandwidth
Degree.
The purpose of the embodiment of the present invention is achieved through the following technical solutions:
A kind of signal bandwidth method of estimation, comprising:
Receipt signal is carried out the conversion of n level welch, wherein, rough estimate is carried out to bandwidth according to the conversion of previous stage welch and adjusts
Whole level welch converts the window length of window function, finally obtains the power spectrum of n level welch conversion；
Maximum according to described power spectrum is modified to described power spectrum；
Revised power spectrum is carried out with pointwise difference, and determines the maximum of points in difference result and minimum point；
Signal bandwidth estimated value is obtained according to the maximum of points in described difference result and minimum point.
A kind of signal bandwidth estimation unit, comprising:
Welch converter unit, for receipt signal is carried out the conversion of n level welch, wherein, converts according to previous stage welch
Bandwidth is carried out with rough estimate to adjust the window length that this grade of welch converts window function, finally obtain the power spectrum of n level welch conversion；
Amending unit, is modified to described power spectrum for the maximum according to described power spectrum；
Difference unit, for carrying out pointwise difference to revised power spectrum, and determines the maximum of points in difference result
And minimum point；
Estimation unit, estimates for obtaining signal bandwidth according to the maximum of points in described difference result and minimum point
Value.
Be can be seen that by adjusting the window function in welch conversion by the technical scheme that the embodiments of the present invention provide
Obtain high-resolution curve, then power spectrum is modified with difference, improve the precision of bandwidth estimation, realize in unknown signaling
The precision of blind estimate bandwidth during parameter.
Brief description
In order to be illustrated more clearly that the technical scheme of the embodiment of the present invention, below will be to required use in embodiment description
Accompanying drawing be briefly described it should be apparent that, drawings in the following description are only some embodiments of the present invention, for this
For the those of ordinary skill in field, on the premise of not paying creative work, other can also be obtained according to these accompanying drawings
Accompanying drawing.
Fig. 1 is signal bandwidth method of estimation schematic flow sheet provided in an embodiment of the present invention.
Fig. 2 is bpsk(binary phase shift in signal bandwidth method of estimation provided in an embodiment of the present invention
Keying, two-phase PSK) modulation block diagram.
Fig. 3 is the power spectrum schematic diagram of 4 grades of welch conversion in signal bandwidth method of estimation provided in an embodiment of the present invention.
Fig. 4 is schematic diagram after power spectrum correction in signal bandwidth method of estimation provided in an embodiment of the present invention.
Fig. 5 is schematic diagram after power spectrum difference in signal bandwidth method of estimation provided in an embodiment of the present invention.
Fig. 6 is signal bandwidth method of estimation application flow schematic diagram provided in an embodiment of the present invention.
Fig. 7 is that signal bandwidth estimation unit provided in an embodiment of the present invention constitutes schematic diagram.
Fig. 8 is emulation experiment schematic diagram data in signal bandwidth method of estimation provided in an embodiment of the present invention.
Specific embodiment
With reference to the accompanying drawing in the embodiment of the present invention, the technical scheme in the embodiment of the present invention is carried out clear, complete
Ground description is it is clear that described embodiment is only a part of embodiment of the present invention, rather than whole embodiments.Based on this
Inventive embodiment, the every other enforcement that those of ordinary skill in the art are obtained under the premise of not making creative work
Example, broadly falls into protection scope of the present invention.
As shown in figure 1, the embodiment of the present invention provides a kind of signal bandwidth method of estimation, comprising:
Step 11, receipt signal is carried out n level welch conversion, wherein, according to previous stage welch conversion bandwidth is carried out
Rough estimate converts the window length of window function to adjust this grade of welch, finally obtains the power spectrum of n level welch conversion；
Step 12, according to the maximum of described power spectrum, described power spectrum is modified；
Step 13, revised power spectrum is carried out with pointwise difference, and determine the maximum of points in difference result and minimum
Value point；
Step 14, signal bandwidth estimated value is obtained according to the maximum of points in described difference result and minimum point.
Signal bandwidth method of estimation be can be seen that by the technical scheme that the embodiments of the present invention provide, by adjustment
Window function in welch conversion obtains high-resolution curve, then power spectrum is modified with difference, improves the essence of bandwidth estimation
Degree, realizes the precision of the blind estimate bandwidth in the parameter of unknown signaling.
As shown in Fig. 2 a kind of schematic diagram of digital signal modulation mode provided in an embodiment of the present invention is it is illustrated that adjust for bpsk
It is assumed that original bandpass signal sequence to be estimated is r (n), this r (n) is that signal passes through receiver front end bandpass filtering sum to system
Wordization sampling (sample frequency fs) output afterwards.
It will be understood by those skilled in the art that multiple digital modulation modes, such as ask(amplitude shift keying,
Amplitude shift keying), 2fsk(frequency-shift keying, frequency shift keying), 4fsk, 8psk, bpsk(binary phase
Shift keying, two-phase PSK), qpsk(quadrature phase shift keying, QPSK),
16qam(quadrature amplitude modulation, quadrature amplitude modulation) mode all can be suitable for.
It will be understood by those skilled in the art that the receipt signal under any band-pass filtering property and sample frequency all can be fitted
With, and embodiment of the present invention signal bandwidth method of estimation can realize higher Stability and veracity.
When n be equal to 4 when, will receipt signal (by after receiver front end bandpass filtering and digitized sampling output
Signal) carry out 4 grades of welch conversion:
A the conversion of (), first order welch includes:
According to fixed window length l0Carry out the conversion of first order welch, to the power Spectral Estimation after the conversion of first order welch
3db bandwidth obtains first order bandwidth estimation value b1, and according to first order bandwidth estimation value b1Obtain second level welch conversion
Window length l1,
Wherein, described fixed window length l0Hanning (Chinese is peaceful) window for 150.
σ1=fs/(10*b1)
l1=fix (100+30* (σ1-1))
Wherein, fsRepresent the sample frequency of receipt signal, b1Represent first order bandwidth estimation value, σ1Represent regulation coefficient, l1
Represent the window length of second level welch conversion, fix () function representation rounds.
Here, simple declaration estimation 3db bandwidth:
3db bandwidth, that is, half power points, corresponding bandwidth is exactly bandwidth before reducing to its half for the power
Degree.
The method estimated of 3db bandwidth is herein: after obtaining the power spectrum chart of first order welch conversion, finds
Maximum of points in power spectrum chart and maximum, carry out traversing at 1/2 point of maximum to both sides from maximum of points, obtain
The end points w of the two 3db bandwidth in left and rightlAnd wh, then 3db bandwidth is asked according to below equation:
Wherein, fsRepresent the sample frequency of receipt signal.
It will be understood by those skilled in the art that the major parameter setting of welch conversion includes window function and Overlapping parameters set
Put, window function selects hanning window, and window length is the adjusted value of every one-level；What Overlapping parameters were selected is default value, need not set
Put.
It will be understood by those skilled in the art that optional, window function can also be rectangular window or blackman(cloth Rec
Graceful) window etc., unrestricted.
B (), second level welch conversion includes:
Window length l according to second level welch conversion1Carry out second level welch conversion, after second level welch conversion
Power Spectral Estimation 3db bandwidth obtains second level bandwidth estimation value b2, and according to second level bandwidth estimation value b2Obtain the third level
Window length l of welch conversion2,
σ2=fs/(10*b2)
l2=fix (100+60* (σ2-1))
Wherein, fsRepresent the sample frequency of receipt signal, b2Represent second level bandwidth estimation value, σ2Represent regulation coefficient, l2
Represent the window length of third level welch conversion, fix () function representation rounds.
C (), third level welch conversion includes:
Window length l according to third level welch conversion2Carry out third level welch conversion, after third level welch conversion
Power Spectral Estimation 0db bandwidth (i.e. main lobe bandwidth estimation) obtains third level bandwidth estimation value b3, and estimated according to third level bandwidth
Evaluation b3Obtain window length l of fourth stage welch conversion3,
σ3=2*fs/(10*b3)
l3=fix (200+150* (σ3-1))
Wherein, fsRepresent the sample frequency of receipt signal, b3Represent third level bandwidth estimation value, σ3For regulation coefficient, l3Table
Show the window length of fourth stage welch conversion, fix () function representation rounds.
Simple declaration estimation 0db bandwidth:
0db bandwidth refers to main lobe bandwidth, is the frequency band that signal energy is mainly concentrated.
D (), fourth stage welch conversion includes:
Window length l according to fourth stage welch conversion3Carry out fourth stage welch conversion, obtain 4 grades of welch transform powers
Spectrum.
Exemplary, as shown in figure 3, the power spectrum chart of 4 grades of welch conversion is it is seen then that convert, through welch, the work(obtaining
Rate spectrum both can obtain high-resolution curve by the window function in suitable adjustment welch conversion, can eliminate in curve again
Burr.Compared with the power spectrum directly being obtained by Fourier transform, change is that power spectrum becomes smoother.
Optionally, when n can be more than 4 more than or equal to 4, n, it is possible to achieve increase the scope estimating bandwidth, but plus
Big n value also can increase amount of calculation, reduces calculating speed.
Specifically, step 12 is modified to described power spectrum according to the maximum of described power spectrum, may include that
Determine the maximum of described power spectrum；
Obtain two adjusting points to both sides traversal centered on the maximum of described power spectrum, the value of described adjusting point is institute
State the 1/m of the maximum of power spectrum, the span of described m can be 3-40, and the selection of m value can be according to the size of signal to noise ratio
Selected, specifically, signal to noise ratio lower m value is less.The value stating adjusting point in the present embodiment is the maximum of described power spectrum
1/20；
Each point between two adjusting points is modified to the maximum of described power spectrum, obtains revised power spectrum.
Exemplary, as shown in figure 4, revised power spectrum chart, the top of curve of pruning, that prunes partly unifies assignment
For maximum, to realize accurate bandwidth estimation.
Specifically, step 13 carries out pointwise difference to revised power spectrum, and determines the maximum of points in difference result
And minimum point, can include；
Calculate in revised power spectrum the difference of each point and its left consecutive points in axis of abscissas direction, and each point with
The difference of the right adjacent rear point in its axis of abscissas direction；
Determining maximum point and minimum point from difference result.
Exemplary, as shown in figure 5, difference is carried out to power spectrum after finishing correction.
Specifically, step 14 according to the maximum of points in described difference result and minimum point obtain signal bandwidth estimate
Value, may include that
First zero point on the left of axis of abscissas direction is searched for according to the maximum of points in difference result；
First zero point on the right side of axis of abscissas direction is searched for according to the minimum point in difference result；
Using described two zero points as signal bandwidth two end points wlAnd wh, then the estimated value of described signal bandwidth b be:
Wherein, b represents signal bandwidth estimated value, fsRepresent the sample frequency of receipt signal.It is poor that zero point refers to power spectrum
Vertical coordinate after point is 0 point.
Exemplary, as shown in figure 5, difference is carried out to power spectrum after finishing correction, after difference, carry out positive and negative spectrum respectively
Peak is searched for, and finds maximum of points and the minimum point of curve, and therebetween partly corresponding is exactly bandwidth estimation value.
In conjunction with the above-mentioned explanation that the embodiment of the present invention is provided with signal bandwidth method of estimation, as shown in fig. 6, the present invention is implemented
Example provides the application flow of signal bandwidth method of estimation, comprising:
Step 61, receive signal r (n):
This r (n) is that signal passes through receiver front end bandpass filtering and digitized sampling (sample frequency fs) output afterwards.
Step 62, be fixed window length welch conversion:
The conversion of first order welch is carried out according to fixed window length.
Step 63, rough estimate 3db bandwidth:
Rough estimate 3db bandwidth is used for adjusting the window length of second level welch conversion.
Step 64, be adjusted window length welch conversion:
Second level welch conversion is carried out according to adjustment window length.
Step 65, rough estimate 3db bandwidth:
Rough estimate 3db bandwidth is used for adjusting the window length of third level welch conversion.
Step 66, be adjusted window length welch conversion:
Third level welch conversion is carried out according to adjustment window length.
Step 67, rough estimate 0db bandwidth:
Rough estimate 0db bandwidth (i.e. main lobe bandwidth estimation) is used for adjusting the window length of fourth stage welch conversion.
Step 68, accurately adjusted window length welch conversion:
Fourth stage welch conversion is carried out according to adjustment window length, obtains high-resolution power spectrum curve.
Step 69, power spectrum correction, difference:
Step 610, respectively maximizing, minima, travel through to the left and right respectively, find first zero point value as estimation
The end points of bandwidth.
Step 611, estimation bandwidth:
Partly corresponding between zero point is exactly bandwidth estimation value.
Be can be seen that by adjusting the window function in welch conversion by the technical scheme that the embodiments of the present invention provide
Obtain high-resolution curve, then power spectrum is modified with difference, improve the precision of bandwidth estimation, realize in unknown signaling
The precision of blind estimate bandwidth during parameter.
As shown in fig. 7, the embodiment of the present invention provides a kind of signal bandwidth estimation unit, comprising:
Welch converter unit 71, for receipt signal is carried out the conversion of n level welch, wherein, becomes according to previous stage welch
Change and bandwidth is carried out with rough estimate to adjust the window length that this grade of welch converts window function, finally obtain the power of n level welch conversion
Spectrum；
Amending unit 72, is modified to described power spectrum for the maximum according to described power spectrum；
Difference unit 73, for carrying out pointwise difference to revised power spectrum, and determines the maximum in difference result
Point and minimum point；
Estimation unit 74, estimates for obtaining signal bandwidth according to the maximum of points in described difference result and minimum point
Value.
Embodiment of the present invention signal bandwidth estimation unit can be separately provided or be arranged at one with receiver.
Signal bandwidth estimation unit be can be seen that by the technical scheme that the embodiments of the present invention provide, by adjustment
Window function in welch conversion obtains high-resolution curve, then power spectrum is modified with difference, improves the essence of bandwidth estimation
Degree, realizes the precision of the blind estimate bandwidth in the parameter of unknown signaling.
The span of n can be equal to 4, or is more than 4, if it is desired to increase estimating that the scope of bandwidth is possible, but
We do not go to attempt.
Still can be found in shown in Fig. 2, a kind of schematic diagram of digital signal modulation mode provided in an embodiment of the present invention is it is illustrated that be
It is assumed that original bandpass signal sequence to be estimated is r (n), this r (n) is that signal is filtered by receiver front end band logical for bpsk modulation
Ripple and digitized sampling (sample frequency fs) output afterwards.
It will be understood by those skilled in the art that multiple digital modulation modes, such as ask(amplitude shift keying,
Amplitude shift keying), 2fsk(frequency-shift keying, frequency shift keying), 4fsk, 8psk, bpsk(binary phase
Shift keying, two-phase PSK), qpsk(quadrature phase shift keying, QPSK),
16qam(quadrature amplitude modulation, quadrature amplitude modulation) mode.
It will be understood by those skilled in the art that the receipt signal under any band-pass filtering property and sample frequency all can be fitted
With, and embodiment of the present invention signal bandwidth method of estimation can realize higher Stability and veracity.
When n be equal to 4 when, that is, welch converter unit 71 by receipt signal (by receiver front end bandpass filtering and digitized
The signal of output after sampling) carry out 4 grades of welch conversion:
A the conversion of (), first order welch includes:
According to fixed window length l0Carry out the conversion of first order welch, to the power Spectral Estimation after the conversion of first order welch
3db bandwidth obtains first order bandwidth estimation value b1, and according to first order bandwidth estimation value b1Obtain second level welch conversion
Window length l1,
Wherein, described fixed window length l0Hanning window for 150.
σ1=fs/(10*b1)
l1=fix (100+30* (σ1-1))
Wherein, fsRepresent the sample frequency of receipt signal, b1Represent first order bandwidth estimation value, σ1Represent regulation coefficient, l1
Represent the window length of second level welch conversion, fix () function representation rounds.
Here, simple declaration estimation 3db bandwidth:
3db bandwidth i.e. half power points, corresponding bandwidth is exactly bandwidth before reducing to its half for the power.
The method estimated of 3db bandwidth is herein: after obtaining the power spectrum chart of first order welch conversion, finds
Maximum of points in power spectrum chart and maximum, carry out traversing at 1/2 point of maximum to both sides from maximum of points, obtain
The end points w of the two 3db bandwidth in left and rightlAnd wh, then 3db bandwidth is asked according to below equation:
Wherein, fsRepresent the sample frequency of receipt signal.
It will be understood by those skilled in the art that the major parameter setting of welch conversion includes window function and Overlapping parameters set
Put, window function selects hanning window, and window length is the adjusted value of every one-level；What Overlapping parameters were selected is default value, need not set
Put.
It will be understood by those skilled in the art that optional, window function can also be rectangular window or blackman(cloth Rec
Graceful) window etc., unrestricted.
B (), second level welch conversion includes:
Window length l according to second level welch conversion1Carry out second level welch conversion, after second level welch conversion
Power Spectral Estimation 3db bandwidth obtains second level bandwidth estimation value b2, and according to second level bandwidth estimation value b2Obtain the third level
Window length l of welch conversion2,
σ2=fs/(10*b2)
l2=fix (100+60* (σ2-1))
Wherein, fsRepresent the sample frequency of receipt signal, b2Represent second level bandwidth estimation value, σ2Represent regulation coefficient, l2
Represent the window length of third level welch conversion, fix () function representation rounds.
C (), third level welch conversion includes:
Window length l according to third level welch conversion2Carry out third level welch conversion, after third level welch conversion
Power Spectral Estimation 0db bandwidth obtains third level bandwidth estimation value b3, and according to third level bandwidth estimation value b3Obtain the fourth stage
Window length l of welch conversion3,
σ3=2*fs/(10*b3)
l3=fix (200+150* (σ3-1))
Wherein, fsRepresent the sample frequency of receipt signal, b3Represent third level bandwidth estimation value, σ3For regulation coefficient, l3Table
Show the window length of fourth stage welch conversion, fix () function representation rounds.
Simple declaration estimation 0db bandwidth:
0db bandwidth refers to main lobe bandwidth, is the frequency band that signal energy is mainly concentrated.
D (), fourth stage welch conversion includes:
Window length l according to fourth stage welch conversion3Carry out fourth stage welch conversion, obtain 4 grades of welch transform powers
Spectrum.
Exemplary, still can be found in shown in Fig. 3, the power spectrum chart of 4 grades of welch conversion is got in return it is seen then that becoming through welch
To power spectrum pass through the window function in suitable adjustment welch conversion and both can obtain high-resolution curve, and song can be eliminated
Burr in line.Compared with the power spectrum directly being obtained by Fourier transform, change is that power spectrum becomes smoother.
Specifically, amending unit 72, can be used for:
Determine the maximum of described power spectrum；
Obtain two adjusting points to both sides traversal centered on the maximum of described power spectrum, the value of described adjusting point is institute
State the 1/m of the maximum of power spectrum, the span of described m can be 3-40, and the selection of m value can be according to the size of signal to noise ratio
Selected, signal to noise ratio lower m value is less.State in the present embodiment adjusting point value be described power spectrum maximum 1/20；
Each point between two adjusting points is modified to the maximum of described power spectrum, obtains revised power spectrum.
Exemplary, still can be shown in Fig. 4, revised power spectrum chart, the top of curve of pruning, that prunes partly unified assigns
It is worth for maximum, to realize accurate bandwidth estimation.
Specifically, difference unit 73, can be used for:
Calculate in revised power spectrum the difference of each point and its left consecutive points in axis of abscissas direction, and each point with
The difference of the right adjacent rear point in its axis of abscissas direction；
Determining maximum point and minimum point from difference result.
Exemplary, still after finishing correction, the power spectrum chart that difference obtains can be carried out to power spectrum shown in Fig. 5.
Specifically, estimation unit 74, can be used for:
First zero point on the left of axis of abscissas direction is searched for according to the maximum of points in difference result；
First zero point on the right side of axis of abscissas direction is searched for according to the minimum point in difference result；
Using described two zero points as signal bandwidth two end points wlAnd wh, then the estimated value of described signal bandwidth b be:
Wherein, b represents signal bandwidth estimated value, fsRepresent the sample frequency of receipt signal.It is poor that zero point refers to power spectrum
Vertical coordinate after point is 0 point.
Exemplary, still after finishing correction, difference can be carried out to power spectrum, carries out positive and negative after difference respectively shown in Fig. 5
Spectrum peak search, finds maximum of points and the minimum point of curve, and therebetween partly corresponding is exactly bandwidth estimation value.
Based on embodiment of the present invention signal bandwidth method of estimation and device, carry out emulation experiment, design parameter such as table 1 institute
Show.
| Systematic parameter | Value |
| Signal carrier frequency | 16mhz |
| Sample frequency | 60mhz |
| Character rate | 3m baud |
| Modulation system | bpsk |
| SNR ranges | [0db,30db] |
| Cycle-index | 100 |
In emulation experiment, bpsk signal, in the range of [0,30] db, selects stepping to be 2.5, for every snr(signal
To noise ratio, signal to noise ratio), carry out 100 independent emulation respectively, calculate the estimation average of this 100 simulation results
With relative error average, draw corresponding curve and observed, simulation result is as shown in Figure 8:
The situation in high snr using the Survey of Bandwidth Estimation Scheme based on welch conversion be can be seen that by the simulation result of Fig. 8
0.002 about estimated accuracy can be reached down.And the mean square error of the estimated value of prior art auto-correlation algorithm is typically 0.1
Above it is impossible to meet practical application request.Namely compared to traditional band width estimation method, using based on welch conversion
Survey of Bandwidth Estimation Scheme estimated accuracy is greatly improved.
In addition, thresholding 1/m during power spectrum correction can be adjusted again when signal to noise ratio is too low.
It will be understood by those skilled in the art that in above-mentioned emulation experiment, qpsk or 8psk modulation system can also be suitable for,
Unrestricted.
It should be understood that disclosed system in several embodiments provided herein, apparatus and method are permissible
Realize by another way.For example, device embodiment described above is only schematically, for example, described unit
Divide, only a kind of division of logic function, actual can have other dividing mode when realizing, for example multiple units or assembly
Can in conjunction with or be desirably integrated into another system, or some features can be ignored, or does not execute.Another, shown or
The coupling each other discussing or direct-coupling or communication connection can be by some interfaces, the indirect coupling of device or unit
Close or communicate to connect, can be electrical, mechanical or other forms.
The described unit illustrating as separating component can be or may not be physically separate, show as unit
The part showing can be or may not be physical location, you can with positioned at a place, or can also be distributed to multiple
On NE.The mesh to realize this embodiment scheme for some or all of unit therein can be selected according to the actual needs
's.
In addition, can be integrated in a processing unit in each functional unit in each embodiment of the present invention it is also possible to
It is that unit is individually physically present it is also possible to two or more units are integrated in a unit.Above-mentioned integrated list
Unit both can be to be realized in the form of hardware, it would however also be possible to employ the form of SFU software functional unit is realized.
If described integrated unit is realized and as independent production marketing or use using in the form of SFU software functional unit
When, can be stored in a computer read/write memory medium.Based on such understanding, technical scheme is substantially
The part in other words prior art being contributed or all or part of this technical scheme can be in the form of software products
Embody, this computer software product is stored in a storage medium, including some instructions with so that a computer
Equipment (can be personal computer, server, or network equipment etc.) executes the complete of each embodiment methods described of the present invention
Portion or part steps.And aforesaid storage medium includes: u disk, portable hard drive, read only memory (rom, read-only
Memory), random access memory (ram, random access memory), magnetic disc or CD etc. are various can store journey
The medium of sequence code.
The above, the only present invention preferably specific embodiment, but protection scope of the present invention is not limited thereto,
Any those familiar with the art in the technical scope of present disclosure, the change or replacement that can readily occur in,
All should be included within the scope of the present invention.Therefore, protection scope of the present invention should be with the protection model of claims
Enclose and be defined.
Claims (8)
1. a kind of signal bandwidth method of estimation is it is characterised in that include:
Receipt signal is carried out the conversion of n level welch, wherein, rough estimate is carried out according to the conversion of previous stage welch to bandwidth and adjusts this
Level welch converts the window length of window function, finally obtains the power spectrum of n level welch conversion；
Maximum according to described power spectrum is modified to described power spectrum；
Revised power spectrum is carried out with pointwise difference, and determines the maximum of points in difference result and minimum point；
Signal bandwidth estimated value is obtained according to the maximum of points in described difference result and minimum point；
Wherein, n is equal to 4,
A the conversion of (), first order welch includes:
According to fixed window length l0Carry out the conversion of first order welch, to the power Spectral Estimation 3db bandwidth after the conversion of first order welch
Obtain first order bandwidth estimation value b1, and according to first order bandwidth estimation value b1Obtain the window length of second level welch conversion
l1,
Wherein, described fixed window length l0Hanning Hanning window for 150,
σ1=fs/(10*b1)
l1=fix (100+30* (σ1-1))
Wherein, fsRepresent the sample frequency of receipt signal, b1Represent first order bandwidth estimation value, σ1Represent regulation coefficient, l1Represent
The window length of second level welch conversion, fix () function representation rounds；
B (), second level welch conversion includes:
Window length l according to second level welch conversion1Carry out second level welch conversion, to the power spectrum after second level welch conversion
Estimate that 3db bandwidth obtains second level bandwidth estimation value b2, and according to second level bandwidth estimation value b2Obtain third level welch to become
Window length l changed2,
σ2=fs/(10*b2)
l2=fix (100+60* (σ2-1))
Wherein, fsRepresent the sample frequency of receipt signal, b2Represent second level bandwidth estimation value, σ2Represent regulation coefficient, l2Represent
The window length of third level welch conversion, fix () function representation rounds；
C (), third level welch conversion includes:
Window length l according to third level welch conversion2Carry out third level welch conversion, to the power spectrum after third level welch conversion
Estimate that 0db bandwidth obtains third level bandwidth estimation value b3, and according to third level bandwidth estimation value b3Obtain fourth stage welch to become
Window length l changed3,
σ3=2*fs/(10*b3)
l3=fix (200+150* (σ3-1))
Wherein, fsRepresent the sample frequency of receipt signal, b3Represent third level bandwidth estimation value, σ3For regulation coefficient, l3Represent the
The window length of level Four welch conversion, fix () function representation rounds；
D (), fourth stage welch conversion includes:
Window length l according to fourth stage welch conversion3Carry out fourth stage welch conversion, obtain 4 grades of welch transform power spectrums.
2. signal bandwidth method of estimation according to claim 1 is it is characterised in that maximum pair according to described power spectrum
Described power spectrum is modified, comprising:
Determine the maximum of described power spectrum；
Obtain two adjusting points to both sides traversal centered on the maximum of described power spectrum, the value of described adjusting point is described work(
The 1/m of the maximum of rate spectrum, described m span is 3-40；
Each point between two adjusting points is modified to the maximum of described power spectrum, obtains revised power spectrum.
3. signal bandwidth method of estimation according to claim 2 is it is characterised in that described carried out to revised power spectrum
Pointwise difference, and determine the maximum of points in difference result and minimum point, comprising:
Calculate the difference of each point and its left consecutive points in axis of abscissas direction in revised power spectrum, and each point is horizontal with it
The difference of the right consecutive points of change in coordinate axis direction；
Determining maximum point and minimum point from difference result.
4. signal bandwidth method of estimation according to claim 3 it is characterised in that described according in described difference result
Maximum of points and minimum point obtain signal bandwidth estimated value, comprising:
First zero point on the left of axis of abscissas direction is searched for according to the maximum of points in difference result；
First zero point on the right side of axis of abscissas direction is searched for according to the minimum point in difference result；
Using described two zero points as signal bandwidth two end points wlAnd wh, then the estimated value of described signal bandwidth b be:
Wherein, b represents signal bandwidth estimated value, fsRepresent the sample frequency of receipt signal.
5. a kind of signal bandwidth estimation unit is it is characterised in that include:
Welch converter unit, for receipt signal is carried out the conversion of n level welch, wherein, converts to band according to previous stage welch
Width carries out the window length that rough estimate converts window function to adjust this grade of welch, finally obtains the power spectrum of n level welch conversion；
Amending unit, is modified to described power spectrum for the maximum according to described power spectrum；
Difference unit, for revised power spectrum is carried out with pointwise difference, and determines maximum of points in difference result and
Little value point；
Estimation unit, for obtaining signal bandwidth estimated value according to the maximum of points in described difference result and minimum point；
Described welch converter unit, specifically for, when n is equal to 4,
A (), first order welch convert:
According to fixed window length l0Carry out the conversion of first order welch, to the power Spectral Estimation 3db bandwidth after the conversion of first order welch
Obtain first order bandwidth estimation value b1, and according to first order bandwidth estimation value b1Obtain the window length of second level welch conversion
l1,
Wherein, described fixed window length l0Hanning Hanning window for 150,
σ1=fs/(10*b1)
l1=fix (100+30* (σ1-1))
Wherein, fsRepresent the sample frequency of receipt signal, b1Represent first order bandwidth estimation value, σ1Represent regulation coefficient, l1Represent
The window length of second level welch conversion, fix () function representation rounds；
B (), second level welch convert:
Window length l according to second level welch conversion1Carry out second level welch conversion, to the power spectrum after second level welch conversion
Estimate that 3db bandwidth obtains second level bandwidth estimation value b2, and according to second level bandwidth estimation value b2Obtain third level welch to become
Window length l changed2,
σ2=fs/(10*b2)
l2=fix (100+60* (σ2-1))
Wherein, fsRepresent the sample frequency of receipt signal, b2Represent second level bandwidth estimation value, σ2Represent regulation coefficient, l2Represent
The window length of third level welch conversion, fix () function representation rounds；
C (), third level welch convert:
Window length l according to third level welch conversion2Carry out third level welch conversion, to the power spectrum after third level welch conversion
Estimate that 0db bandwidth obtains third level bandwidth estimation value b3, and according to third level bandwidth estimation value b3Obtain fourth stage welch to become
Window length l changed3,
σ3=2*fs/(10*b3)
l3=fix (200+150* (σ3-1))
Wherein, fsRepresent the sample frequency of receipt signal, b3Represent third level bandwidth estimation value, σ3For regulation coefficient, l3Represent the
The window length of level Four welch conversion, fix () function representation rounds；
D (), fourth stage welch convert:
Window length l according to fourth stage welch conversion3Carry out fourth stage welch conversion, obtain 4 grades of welch transform power spectrums.
6. signal bandwidth estimation unit according to claim 5 is it is characterised in that described amending unit, specifically for:
Determine the maximum of described power spectrum；
Obtain two adjusting points to both sides traversal centered on the maximum of described power spectrum, the value of described adjusting point is described work(
The 1/m of the maximum of rate spectrum, described m span is 3-40；
Each point between two adjusting points is modified to the maximum of described power spectrum, obtains revised power spectrum.
7. signal bandwidth estimation unit according to claim 6 is it is characterised in that described difference unit, specifically for:
Calculate the difference of each point and its left consecutive points in axis of abscissas direction in revised power spectrum, and each point is horizontal with it
The difference of the right consecutive points of change in coordinate axis direction；
Determining maximum point and minimum point from difference result.
8. signal bandwidth estimation unit according to claim 7 is it is characterised in that described estimation unit, specifically for:
First zero point on the left of axis of abscissas direction is searched for according to the maximum of points in difference result；
First zero point on the right side of axis of abscissas direction is searched for according to the minimum point in difference result；
Using described two zero points as signal bandwidth two end points wlAnd wh, then the estimated value of described signal bandwidth b be:
Wherein, b represents signal bandwidth estimated value, fsRepresent the sample frequency of receipt signal.
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