CN106646534A - Wavelet transform based multipath inhibiting method and system thereof - Google Patents
Wavelet transform based multipath inhibiting method and system thereof Download PDFInfo
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- CN106646534A CN106646534A CN201610994212.5A CN201610994212A CN106646534A CN 106646534 A CN106646534 A CN 106646534A CN 201610994212 A CN201610994212 A CN 201610994212A CN 106646534 A CN106646534 A CN 106646534A
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S19/00—Satellite radio beacon positioning systems; Determining position, velocity or attitude using signals transmitted by such systems
- G01S19/01—Satellite radio beacon positioning systems transmitting time-stamped messages, e.g. GPS [Global Positioning System], GLONASS [Global Orbiting Navigation Satellite System] or GALILEO
- G01S19/13—Receivers
- G01S19/22—Multipath-related issues
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Abstract
The invention relates to a wavelet transform based multipath inhibiting method and a system thereof. The method includes steps of performing carrier stripping treatment in a frequency mixer; performing pseudo code stripping on signals through a correlator and outputting a plurality of correlation values; obtaining pseudo code phase discrimination errors through calculation; and finally adjusting pseudo codes in a local pseudo code generator so as to achieve the aim of inhibition. The invention also includes the system including a signal receiver, the frequency mixer, a data processor, a wavelet phase discriminator, a loop filter and the local pseudo code generator. According to the invention, a wavelet transform method is utilized for code loop multipath inhibition and a characteristic of wavelet transform that the wavelet transform can be used for detecting signal singularity is utilized, the code loop phase discrimination errors are obtained, so that the structure of a traditional phase discriminator is changed and an aim of multipath inhibition is achieved effectively.
Description
Technical field
The present invention relates to satellite navigation signals process field, more particularly to a kind of multipaths restraint method based on wavelet transformation
And its system.
Background technology
At present multipaths restraint is the hot issue of field of satellite navigation research, multipaths restraint be in fact divided into suppression technology with
Technology for eliminating, wherein suppression technology are to go to reduce impact of the multipath to receiver as possible, and technology for eliminating is then complete in theory
Totally disappeared except multipath effect.
From satellite-signal and designing for reception antenna the method for realizing multipaths restraint is sent by actuality and versatility
Restriction, and by location navigation calculate method can not effectively suppress multipath, therefore, enter from Digital Signal Processing
Hand finds effectively multipaths restraint method, but from the above, at present existing a few class multipaths restraint technologies are not all accounted for
Non-Gaussian noise environment, and the algorithm performance assumed based on Gauss under non-Gaussian environment occurs degeneration, this results in multipath suppression
The obvious reduction of effect processed, positioning precision are deteriorated, therefore, the multipaths restraint technology studied under non-Gaussian environment has necessity
And practical significance.
The content of the invention
The technical problem to be solved is due to designing that to send realization more from satellite-signal and reception antenna
The method that footpath suppresses is limited by actuality and versatility, and the method calculated by location navigation can not effectively be suppressed
Multipath.
The present invention is as follows for the technical scheme for solving above-mentioned technical problem：A kind of multipaths restraint side based on wavelet transformation
Method, the method comprises the steps：
S1, input intermediate-freuqncy signal carries out carrier wave lift-off processing with local carrier signal by frequency mixer；
S2, the signal after carrier wave is peeled off in step S1 is respectively with output in local pseudo-code generator at least
The local pseudo-code of 2 outs of phase through correlator, the pseudo-code in the signal is peeled off simultaneously, obtains at least 2 correlation letters
Number；
S3, at least 2 correlation value signals exported after correlator process in step S2, is carried out through small echo phase discriminator
Wavelet transformation obtains the position of described correlation value signal scope discontinuity, is obtained according to the position calculation of the scope discontinuity
Pseudo-code phase demodulation error amount；
S4, the pseudo-code phase demodulation error amount in step S3 is reached through loop filter with local pseudo-code data controlled oscillator
Local pseudo-code generator, adjusts the pseudo-code in local pseudo-code generator.
The invention has the beneficial effects as follows：A yard technology for ring multipaths restraint is carried out using small wave converting method, in analysis pseudo-code
On the basis of auto-correlation function curve, the characteristics of using wavelet transformation energy detection signal singularity, a yard ring phase demodulation error is provided, from
And traditional phase discriminator structure is changed, the purpose for effectively suppressing multipath can be reached.
On the basis of above-mentioned technical proposal, the present invention can also do following improvement.
Further, the pseudo-code produced by local pseudo-code generator is after multi-channel time-delay, according to the pseudo-code signal after time delay
Judge i.e. time-code.
Further, at least 2 correlation value signals in the S2 obtain at least 2 accumulated values and are formed after integration is cumulative
Pseudo-code correlation function curve, pseudo-code correlation function curve is used for wavelet transformation in S3.
Further, wavelet transformation uses resolution analytic approach and Mallat algorithms.
Further, wavelet transformation uses db3 small echos, and small echo change is carried out to pseudo-code auto-correlation function using db3 small echos
Change.
It is using the beneficial effect of above-mentioned further scheme：Using the discretization of small echo, be conducive to the convenience for calculating, accelerate
The efficiency of calculating, when signal carries out wavelet transformation, selects correct wavelet function, is not result in be detected after signal conversion
Structure it is inaccurate, it can be ensured that the normal operation of wavelet transformation.
The invention further relates to a kind of multipaths restraint system based on wavelet transformation, the system includes：Signal receiver, mixing
Device, data processor, small echo phase discriminator, loop filter, local pseudo-code generator；
Signal receiver, frequency mixer, data processor, small echo phase discriminator, loop filter, local pseudo-code generator and number
It is sequentially connected in series to form loop according to processor；
Signal receiver, for receiving intermediate frequency signal and local carrier signal；
Frequency mixer, for the intermediate-freuqncy signal and local carrier signal in signal receiver to be carried out into carrier wave lift-off processing；
Data processor, the local pseudo-code of the multiple outs of phase exported with local pseudo-code generator is through frequency mixer load
Pseudo-code in the signal that ripple is stripped out is peeled off, and obtains at least 2 correlation value signals；
These signals, for the signal after the process of receiving data processor, are carried out wavelet transformation by small echo phase discriminator, are calculated
Obtain pseudo-code phase demodulation error amount；
Loop filter, with the pseudo-code phase demodulation error amount for obtaining the pseudo-code in local pseudo-code generator is adjusted.
The beneficial effect of foregoing invention：A yard technology for ring multipaths restraint is carried out using small wave converting method, in analysis pseudo-code
On the basis of auto-correlation function curve, the characteristics of using wavelet transformation energy detection signal singularity, a yard ring phase demodulation error is provided, from
And traditional phase discriminator structure is changed, the purpose for effectively suppressing multipath can be reached.
Further, described data processor includes：At least 2 correlators parallel with one another, frequency mixer respectively with these
Correlator is connected.
Further, successively time delay is input into each correlator to the pseudo-code that local pseudo-code generator is produced.
Further, the cosine value of local carrier signal is read by cosine table.
Using beneficial effects of the present invention：Using such cyclic system, multipaths restraint effect is improve, improve positioning
Precision.
Description of the drawings
Fig. 1 is the pseudo-code tracing loop structure schematic diagram of the small echo phase demodulation of the present invention；
Fig. 2 is the multipaths restraint method flow diagram of the wavelet transformation of the present invention；
Fig. 3 is the direct signal and the auto-correlation function curve synoptic diagram with different multipath signals of the present invention；
Fig. 4 is the Mallat wavelet function feedback wave filter group schematic diagrames of the present invention；
Fig. 5 is the multilevel wavelet decomposition and reconstruction wave filter group schematic diagram of the present invention；
Fig. 6 is the auto-correlation function curve synoptic diagram during the pseudo-code tracing of the present invention；
Pseudo-code auto-correlation function curve synoptic diagram when Fig. 7 is the signal to noise ratio snr=- 20dB of the present invention；
Fig. 8 is that the present invention utilizes db3 small echos that the wavelet transform result obtained by 3 layers of Scale Decomposition is carried out to auto-correlation function
Schematic diagram；
This method and EML phase detecting method pseudo-code tracings error curve are illustrated when Fig. 9 has a multipath signal for the present invention
Figure；
This method and EML phase detecting method pseudo-code tracings error curve are illustrated when Figure 10 has three multipath signals for the present invention
Figure.
Specific embodiment
The principle and feature of the present invention are described below in conjunction with accompanying drawing, example is served only for explaining the present invention, and
It is non-for limiting the scope of the present invention.
As shown in Figure 2, a kind of multipaths restraint method based on wavelet transformation, the method comprises the steps：
S1, input intermediate-freuqncy signal carries out carrier wave lift-off processing with local carrier signal by frequency mixer；
S2, in step S1 through carrier wave peel off after signal respectively with local pseudo-code generator in export at least 2
The local pseudo-code of out of phase through correlator, the pseudo-code in the signal is peeled off simultaneously, obtains at least 2 correlation value signals；
S3, at least 2 correlation value signals exported after correlator process in step S2, is carried out through small echo phase discriminator
Wavelet transformation obtains the position of described correlation value signal scope discontinuity, is obtained according to the position calculation of the scope discontinuity
Pseudo-code phase demodulation error amount；
S4, the pseudo-code phase demodulation error amount in step S3 reaches local through loop filter and local pseudo-code data controlled oscillator
Pseudo-code generator, adjusts the pseudo-code in local pseudo-code generator.
As shown in figure 1, a kind of multipaths restraint system based on wavelet transformation, the system includes：Signal receiver, mixing
Device, data processor, small echo phase discriminator, loop filter, local pseudo-code generator；
Signal receiver, frequency mixer, data processor, small echo phase discriminator, loop filter, local pseudo-code generator and number
It is sequentially connected in series to form loop according to processor；
Signal receiver, for receiving intermediate frequency signal and local carrier signal；
Frequency mixer, for the intermediate-freuqncy signal and local carrier signal in signal receiver to be carried out into carrier wave lift-off processing；
Data processor, the local pseudo-code of the multiple outs of phase exported with local pseudo-code generator is through frequency mixer load
Pseudo-code in the signal that ripple is stripped out is peeled off, and obtains at least 2 correlation value signals；
These signals, for the signal after the process of receiving data processor, are carried out wavelet transformation by small echo phase discriminator, are calculated
Obtain pseudo-code phase demodulation error amount；
Loop filter, with the pseudo-code phase demodulation error amount for obtaining the pseudo-code in local pseudo-code generator is adjusted.
1st, pseudo-code auto-correlation function scope discontinuity principle of invariance
In the case where navigation data d (t) is not considered, multipath signal model can be write as
Assume that at this moment carrier wave has been carried out synchronization, and A=1, then what is obtained Jing after local pseudo-code correlation same aligns branch road
Correlation be
Wherein,For direct signal pseudo-code time delay estimate,For direct signal pseudorandom codes phase estimation error,
Then the auto-correlation function of pseudo-code can be expressed as
Because the pseudo-code time delay of multipath signal is more than the pseudo-code time delay of direct signal, i.e. τi≥τ0, i=1 ... M, then
τ0-τi≤ 0, i=1 ... M (1-4)
From formula (1-2), (1-3) and (1-4), when τ is by-τcChange to τcDuring, the auto-correlation function R ' of pseudo-code
(τ) point for nonzero value occur be with (1-3) formula equal sign the right Section 2 it is unrelated, i.e., be with multipath signal it is unrelated, thus
Understand that the pseudo-code auto-correlation function scope discontinuity with multipath signal is not change with the presence or absence of multipath signal, Fig. 3 difference
Give and do not exist multipath signal, there is a multipath signal, there are two multipath signals and there are three multipath signal situations
Under GPS pseudo-code auto-correlation function curves, from figure it is also seen that the position of auto-correlation function scope discontinuity receive multipath
The presence or absence of signal affects, therefore, detect the pseudo- code-phase that the position of auto-correlation function slope of curve catastrophe point just can obtain now
Position tracking error, so as to realize tracking direct signal pseudo-code under the influence of not by multipath signal.
2nd, the conversion inflection point detection based on wavelet transformation
In pseudo-code auto-correlation function scope discontinuity principle of invariance, scope discontinuity is unusual for a class of function curve
Point, the thought of wavelet analysis is derived from flexible and shift method, can accurately detect the position of catastrophe point.
(1) continuous wavelet transform and its discretization
Wavelet function is definitely defined as：If ψ (t) is a quadractically integrable function, i.e. ψ (t) ∈ L2(R), when Fourier becomes
The condition for changing ψ (ω) satisfactions is as follows：
ψ (t) is just claimed to be a wavelet function, wherein, formula (1-5) is the tolerable condition of wavelet function.To obtain
One continuous wavelet series, can carry out flexible translation by wavelet mother function ψ (t).Order：
In formula (1-6), a represents scale factor, and b represents shift factor, ψabT () represents wavelet basis function, it depends on ginseng
Number a, b, because a and b are continuous changes, ψabT () is called and does continuous wavelet function base.
Because in practice computer cannot be simulated process, only signal is carried out into discrete could convenience and analyzed and place
Reason, therefore, in order to computer is easily achieved, by wavelet discreteization process, at present conventional method is to carry out dyadic wavelet transform,
It is ordered series of numbers { 2 to choose scale parameterj}j∈Z。
The definition of dyadic wavelet is given first below, it is assumed that ψ ∈ L2(R)∩L1(R), and there is constant A, B, wherein 0 ＜ A
≤ B ＜ ∞ so that meet following formula
Then ψ is called dyadic wavelet, and formula (1-7) is stability condition, and during and if only if A=B most stable state can be reached.
For dyadic wavelet function ψ, order
It is 2 that yardstick can be obtainedjWith the function f that position is x, its wavelet transformation formula is as follows：
Claim sequenceIt is dyadic wavelet transform, W is its transformation operator, when yardstick is 2jWhen,
For the detail signal of f (x).
(2) multiresolution analysis and Mallat algorithms
When the local characteristicses to signal are analyzed, always wish that construct one all has good office in time domain, frequency domain
The wavelet basis of portion's characteristic.The method of existing wavelet structure base has 2 kinds：1st, direct structured approach, but the wavelet basis that this method finds
Cannot simultaneously have good localization property on time-frequency domain；2nd, multiresolution algorithm, also known as spatial decomposition method, it sets up
On the basis of function space concept, it is decomposed into a series of son skies with certain characteristic according to certain rule function space
Between sequence.The property that multiresolution analysis have is as follows：
(1) dull uniformity：Vj∈Vj+1, to any j ∈ Z
(2) progressive completeness：
(3) flexible completeness：
(4) translation invariance：
(5) Riesz bases existence：There is φ (t) ∈ V0So that { φj(2-j/2T-k) | k ∈ Z } constitute VjRiesz bases.
Being described as follows with regard to Riesz：
If φ (t) is V0Riesz bases, then there is constant A, B, and cause：
I.e. following formula is set up
Multiresolution analysis can be constructed to function space, and these function spaces be it is mutually nested, i.e.,
The space that wavelet function is constituted is the difference of two neighboring function space, i.e.,
It is rightDue toSo rightThere are g (x) ∈ Vj+1, then the expansion of φ (t) can be with
It is expressed as
Assume arbitrary signal f (t) ∈ Vj-1In Vj-1The expansion in space is：
F (t) is once decomposed, i.e., is projected to metric space V respectivelyjWith wavelet space WjFor：
cj,kAnd dj,kIt is the expansion coefficient on j yardsticks, while having：
Make 2-jT-k=2-jT ', then have 2-(j-1)T-n=2-(j-1)T '+2k-n, are obtained by formula (1-17)
Can be obtained by above equation
Above equation is exactly the expression formula of Mallat wavelet decompositions, so, as long as calculating SPACE Vj-1Decomposition coefficient,
Just expansion coefficient h (n) and g (n) can be multiplied accumulating respectively with it, so as to obtain in SPACE VjAnd WjDecomposition coefficient.
Similar, from multiresolution analysisVj⊥Wj, therefore exist
Do inner product with f (t) simultaneously and obtain in above formula both sides
Above formula is the expression formula of Mallat wavelet reconstructions, and Fig. 4 gives filter bank structure figure, the low pass decomposed in figure
The unit impact response of wave filter and high-pass filter is respectively h (- n) and g (- n), the low pass filter of reconstruct and high-pass filtering
The unit impact response of device is respectively h (n) and g (n).May certify that formula (1-19), (1-20) and (1-21) with the knot shown in Fig. 3
Composition is equivalent.
Figure 3 above give and decomposition and reconstruction schematic diagram, when multi-stage transformation is generalized to, the mode of reconstruct
Similar, Fig. 4 gives the structural representation of many hierarchical reconfiguration algorithms.
(3) singular points detection
In signal analysis, Singular Point contains critically important information, the left side singular point of auto-correlation function curve
Code phase demodulation control information now is contained, thus particularly important are analyzed to singular points, and wavelet transformation is strange to signal
Dissimilarity has very high sensitivity, and it has been successfully applied in rim detection and time varying signal detection, and this section will be introduced
The method that Singularity Detection is carried out to signal using wavelet transformation.
Wavelet transformation is usually portrayed the local orthotropicity of function, the maximum of WAVELET TRANSFORM MODULUS by Lipschitz indexes
Singular points, and the speed speed decayed and singular point can be converged under conditions of yardstick is very fine
Lipschitz indexes are relevant.
If n is the integer not less than zero, n ＜ α≤n+1, if having constant A and h0＞ 0, with polynomial of degree n Pn(h), to any
H≤h0, have
|f(x0+h)-Pn(h)|≤A|h|α (1-22)
Then claim f (x) in point x0For Lipschitz index α, PnH () is exactly f (x) in x0Point is done before Taylor series expansions
N items.
As can be seen that function is in point x0The singularity size at place can be portrayed by the Lipschitz index α of f (x), f (x)
In x0More smooth, α is bigger, and vice versa, for pseudo-code auto-correlation ramp function R ' (τ) as shown in Figure 3, its slope mutation again
Can be micro- at point, but first derivative is discontinuous, and its Lipschitz index is just 1.
In addition, when wavelet transformation is carried out to signal, select correct wavelet function most important, if the small echo letter for selecting
Number is improper, and it is probably inaccurate even wrong that the testing result obtained after line translation is entered to signal, thus, herein to pseudo-code
When auto-correlation function curve carries out wavelet transformation and selects wavelet function, some below consideration is needed：
(1) ψ (t) has compactly support；
(2) ψ (t) continuously differentiables；
(3) ψ (t) has N rank vanishing moments；
(4) ψ (t) has symmetry.
The Orthogonal Wavelets for meeting above-mentioned condition are the foundations for selecting wavelet function herein.
3rd, the track loop based on wavelet transformation is designed
Based on above-mentioned analysis, it is assumed that in pseudo-code tracing loop, carrier wave is synchronized, and in acquisition phase by pseudo-code
Error is brought up within half-chip, if the width of a chip is τc, the sampling number of a chip is N, to obtain multipath
Pseudo-code auto-correlation function under interference, line delay is entered successively to locally generated pseudo-code every a sampled point, and (M can be with to obtain M
Take 1.5N≤M≤2N) the local pseudo-code of road out of phase, then to the output of frequency mixer carry out it is related after send into M integration and add up
Device is added up, and M accumulated value after adding up forms the auto-correlation function curve of pseudo-code, carries out wavelet transformation to it afterwards and obtains
The position of scope discontinuity, reaches pseudo-code phase demodulation purpose.
Fig. 6 gives auto-correlation function curve that is unrealized and realizing pseudo-code tracing, it can be seen that ought be completely real
During existing pseudo-code tracing, the scope discontinuity of auto-correlation function should be in 1 τc(IPThe position of the super previous chip of branch road), it is assumed that it is pseudo-
T during code tracking, detects the starting point of auto-correlation function in n τcPosition, then phase demodulation error D nowerrCan be with
It is expressed as
Derr=(n-1) τc (1-23)
Said process can be understood as a kind of small echo phase discriminator, and it changes traditional phase discriminator structure, uses wavelet transformation
Through being calculated pseudo- code error behind detection auto-correlation function slope of curve catastrophe point position.The accuracy of identified result with one
The sampling number of chip is directly proportional, and higher accuracy can increase the complexity of realization, therefore, to take in actual applications
House, the pseudo-code tracing loop structure that a kind of new multipaths restraint method that this patent is proposed is formed is as shown in figure 1, in Fig. 1
Pseudo-code produced by local pseudo-code generator obtains i.e. time-code after the time delay of M roads, and loop operates mainly in pseudo-code auto-correlation letter
The left side of number curve.
4th, performance simulation and analysis
This patent carries out wavelet transformation using db3 small echos to pseudo-code auto-correlation function；Adopt code length for 1023 C/A codes,
And the sampling number of a chip is set as 100.Because impact very little of the carrier wave to multipath, then can simultaneously assume that carrier wave has been carried out
It is synchronous, the simple inhibition for investigating said method to multipath, and with traditional lead-lag (EarlyMinusLate, EML)
Phase detecting method is contrasted.
(1) pseudo-code auto-correlation function slope of curve Singularity detection
Because the pseudo-code auto-correlation function curve for being formed in practice is not smooth, Fig. 7 and Fig. 8 is given works as noise respectively
Auto-correlation function curve (one section of left side) when than SNR being -20dB and it is carried out after 3 layers of Scale Decomposition using db3 small echos
Wavelet transform result curve.As shown in fig. 7, auto-correlation function slope of a curve catastrophe point is in the 80th sampling when without noise
Point, and it is subject to the catastrophe point of the slope of curve of noise pollution to become not substantially, in Fig. 8, to the auto-correlation function by noise pollution
Curve carries out wavelet transformation, by the modulus maximum property of wavelet transformation, can significantly detect the position of scope discontinuity.
(2) simulation result of pseudo-code tracing error compares
Fig. 9 and Figure 10 sets forth under conditions of signal to noise ratio snr=- 20dB, be respectively present one and three multipaths
During signal, the pseudo-code tracing application condition curve of context of methods and EML phase detecting methods, wherein, the multipath of a multipath signal declines
Subtract coefficient a1=0.6, code time delay τ1=0.4 τc；The multipath fading coefficient of three multipath signals is a1=0.6, a2=0.2, a3=
0.3, code time delay is respectively τ1=0.4 τc,τ2=0.2 τc,τ3=0.3 τc, as can be seen that context of methods pair from Fig. 9 and Figure 10
The bar number of multipath is insensitive, and after error is stable, traditional early pseudo-code delay locked loop late has larger tracking error,
And the pseudo-code tracing loop of this method can realize accurate tracking.
In this manual, identical embodiment or example are necessarily directed to the schematic representation of above-mentioned term.
And, the specific features of description, structure, material or feature can be in any one or more embodiments or example with suitable
Mode is combined.Additionally, in the case of not conflicting, those skilled in the art can be by the difference described in this specification
The feature of embodiment or example and different embodiments or example is combined and combines.
The foregoing is only presently preferred embodiments of the present invention, not to limit the present invention, all spirit in the present invention and
Within principle, any modification, equivalent substitution and improvements made etc. should be included within the scope of the present invention.
Claims (9)
1. a kind of multipaths restraint method based on wavelet transformation, it is characterised in that the method comprises the steps：
S1, input intermediate-freuqncy signal carries out carrier wave lift-off processing with local carrier signal by frequency mixer；
S2, the signal after carrier wave is peeled off in step S1 is different from least 2 exported in local pseudo-code generator respectively
The local pseudo-code of phase place through correlator, the pseudo-code in the signal is peeled off simultaneously, obtains at least 2 correlation value signals；
S3, at least 2 correlation value signals exported after correlator process in step S2, through small echo phase discriminator small echo is carried out
Conversion obtains the position of described correlation value signal scope discontinuity, and according to the position calculation of the scope discontinuity pseudo-code is obtained
Phase demodulation error amount；
S4, the pseudo-code phase demodulation error amount in step S3 reaches local pseudo-code through loop filter with local pseudo-code data controlled oscillator
Generator, adjusts the pseudo-code in local pseudo-code generator.
2. a kind of multipaths restraint method based on wavelet transformation according to claim 1, it is characterised in that local pseudo-code is sent out
Pseudo-code produced by raw device judges i.e. time-code after multi-channel time-delay according to the pseudo-code signal after time delay.
3. a kind of multipaths restraint method based on wavelet transformation according to claim 2, it is characterised in that in the S2
At least 2 correlation value signals obtain at least 2 accumulated values after integration is cumulative and form pseudo-code correlation function curve, and pseudo-code is related
Function curve is used for wavelet transformation in S3.
4. a kind of multipaths restraint method based on wavelet transformation according to claim 1, it is characterised in that wavelet transformation is adopted
It is to differentiate analytic approach and Mallat algorithms.
5. a kind of multipaths restraint method based on wavelet transformation according to claim 4, it is characterised in that wavelet transformation is adopted
It is db3 small echos, wavelet transformation is carried out to pseudo-code auto-correlation function using db3 small echos.
6. the system of a kind of multipaths restraint method based on wavelet transformation described in any one of utilization claim 1-5, its feature
It is that the system includes：Signal receiver, frequency mixer, data processor, small echo phase discriminator, loop filter, local pseudo-code are sent out
Raw device；
At signal receiver, frequency mixer, data processor, small echo phase discriminator, loop filter, local pseudo-code generator and data
Reason device is sequentially connected in series to form loop；
Signal receiver, for receiving intermediate frequency signal and local carrier signal；
Frequency mixer, for the intermediate-freuqncy signal and local carrier signal in signal receiver to be carried out into carrier wave lift-off processing；
Data processor, the local pseudo-code of the multiple outs of phase exported with local pseudo-code generator is through the stripping of frequency mixer carrier wave
The pseudo-code separated out in the signal for coming is peeled off, and obtains at least 2 correlation value signals；
These signals, for the signal after the process of receiving data processor, are carried out wavelet transformation by small echo phase discriminator, are calculated
Pseudo-code phase demodulation error amount；
Loop filter, with the pseudo-code phase demodulation error amount for obtaining the pseudo-code in local pseudo-code generator is adjusted.
7. a kind of multipaths restraint system based on wavelet transformation according to claim 6, it is characterised in that described data
Processor includes：At least 2 correlators parallel with one another, frequency mixer is connected respectively with these correlators.
8. a kind of multipaths restraint system based on wavelet transformation according to claim 7, it is characterised in that local pseudo-code is sent out
Successively time delay is input into each correlator to the pseudo-code that raw device is produced.
9. a kind of multipaths restraint system based on wavelet transformation according to claim 6, it is characterised in that local carrier is believed
Number cosine value by cosine table read.
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Cited By (2)
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|---|---|---|---|---|
| CN108594273A (en) * | 2018-05-03 | 2018-09-28 | 中国人民解放军国防科技大学 | Carrier phase multipath suppression method based on time-reference code reference waveform design |
| CN109086248A (en) * | 2018-06-15 | 2018-12-25 | 西安科技大学 | A kind of fault signal analysis method based on Phase information modulus maximum line |
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