CN108627857A - Multi-path detecting method, device and GNSS receiver - Google Patents
Multi-path detecting method, device and GNSS receiver Download PDFInfo
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- CN108627857A CN108627857A CN201710161199.XA CN201710161199A CN108627857A CN 108627857 A CN108627857 A CN 108627857A CN 201710161199 A CN201710161199 A CN 201710161199A CN 108627857 A CN108627857 A CN 108627857A
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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
A kind of multi-path detecting method of present invention offer, device and GNSS receiver.The method includes:Obtain current carrier-to-noise ratio CN0 and code relevant peaks;Calculate the diff values for being used for descriptor code relevant peaks distortion degree under current carrier-to-noise ratio;Store the diff values and current carrier-to-noise ratio;Judge whether the quantity of the diff values of storage is more than predetermined value;When the quantity of the diff values of judgement storage is not more than predetermined value, judge whether single diff values are more than the corresponding threshold values Th of current carrier-to-noise ratio;As judgement single diff values threshold values Th corresponding more than current carrier-to-noise ratio, it is determined with multipath, otherwise judges no multipath;When the quantity of the diff values of judgement storage is more than predetermined value, multipath is judged whether according to diff Data-Statistics information.The present invention can improve the reliability and precision of multipath detection, and can distinguish the multipath type detected.
Description
Technical field
The present invention relates to a kind of technical field of satellite navigation more particularly to multi-path detecting method, device and GNSS receivers.
Background technology
In urban environment, especially AGNSS (Assisted Global Navigation Satellite System,
Assisted global navigational satellite system) and difference information auxiliary under, multipath has become the main error source of satellite navigation receiver.
Multipath effect (multipath effect) refers to electromagnetic wave after different propagateds, and each component reaches destination time not
Together, and by respective Phase Stacking it interferes so that distorted signals originally.In addition to ionospheric error, multipath effect is to make
At the principal element of navigation neceiver position error.Especially under the adverse circumstances such as urban canyons, both there is strong reflection diameter,
Possible line of sight is even disappeared completely by energy dropoff is blocked again.In these cases, the relevant peaks of direct signal can be reflected
Signal corruption leads to tracking error;Or direct signal completely disappears, receiver tracking reflection diameter on, cause it is prodigious with
Track error.According to the relationship of direct signal and reflection signal (multipath signal), signal environment can be roughly divided into four classes.First, only having
Direct signal, areflexia signal or reflection signal are very weak;Second is that direct signal is most strong, reflection signal is weaker but to through
The relevant peaks of signal cause to significantly affect;Third, reflection signal is better than direct signal, but direct signal there are still;Fourth, only having
Reflect signal, no direct signal.The first ideal situation, without multipath error.Under second case, using narrow the relevant technologies
Most multipath error can be eliminated.For third and fourth situation, reflection signal accounts for leading factor, the multipath based on correlator
Technology for eliminating is invalid.Moreover, it is all possible that reflected path grows hundreds of meters compared with direct signal, prodigious measurement can be caused to miss
Difference.
There are mainly two types of existing multi-path detecting methods, and one is the exceptions according to code loop adjustment amount and signal carrier-to-noise ratio
Multipath detection is done in variation, and under no multipath conditions, carrier-to-noise ratio variation is steady.For having the code ring of photocarrier method, the adjustment amount of code
It is the Gaussian Profile that a mean value is 0;And in the case where there is multi-path jamming, due to the interference of reflected diameter, receive the energy meeting of signal
While having fluctuating, since relevant peaks are distorted, the adjustment amount of code ring will not be the Gaussian Profile that mean value is 0 again.It is another
It is to detect multipath according to the symmetry of code relevant peaks or so slope whether there is, under noiseless, code relevant peaks are one symmetrical three
It is angular, both sides straight slope and be 0;Under multi-path jamming, code relevant peaks are distorted, both sides slope and be no longer 0.
In the implementation of the present invention, inventor has found at least to have the following technical problems in the prior art:
According to the method that the anomalous variation of code loop adjustment amount and signal carrier-to-noise ratio does multipath detection, the adjustment amount of code ring by
To the limitation of code loop bandwidth, and the usual very little of bandwidth of code ring, it is thus possible to cause detection sluggish, and this method can only judge
Multipath whether there is, and multipath type cannot be distinguished;And multipath is detected according to the symmetry of code relevant peaks or so slope and whether there is,
Relevant peaks are equivalent to triangle, compare the slope of both sides straight line, but relevant peaks are not ideal triangular, straight line models meeting
Information is lost, especially when the sampled point to relevant peaks is more.To sum up, the reliability and precision of existing multi-path detecting method
It is not high, and the multipath type detected cannot be distinguished.
Invention content
Multi-path detecting method, device and GNSS receiver provided by the invention, can improve multipath detection reliability and
Precision, and the multipath type detected can be distinguished.
In a first aspect, the present invention provides a kind of multi-path detecting method, including:
Obtain current carrier-to-noise ratio CN0 and code relevant peaks;
Calculate the diff values for being used for descriptor code relevant peaks distortion degree under current carrier-to-noise ratio;
Store the diff values and current carrier-to-noise ratio;
Judge whether the quantity of the diff values of storage is more than predetermined value;
When the quantity of the diff values of judgement storage is not more than predetermined value, judge whether single diff values are more than when front bearing is made an uproar
Than corresponding threshold values Th;
As judgement single diff values threshold values Th corresponding more than current carrier-to-noise ratio, it is determined with multipath, otherwise judgement is without more
Diameter;
When the quantity of the diff values of judgement storage is more than predetermined value, judged whether according to diff Data-Statistics information more
Diameter.
Optionally, after the current carrier-to-noise ratio of the acquisition and code relevant peaks, the method further includes:
It calculates on the left of code relevant peaks and the general of difference diff_left_right occurs between distortion and the right side distortion of code relevant peaks
Rate diff_left_right_probability;
Diff_left_right_probability is filtered, is obtained
diff_left_right_probability_filtered。
Optionally, described to judge whether that multipath includes according to diff Data-Statistics information:
Calculate the mean value AV of all diff values of storagediffAnd variances sigmadiff, and the mean value of all CN0 that is stored
AVCN0And variances sigmaCN0;
According to the mean value AV of CN0CN0And variances sigmaCN0Determine threshold values THAVAnd THσ;
Judge AVdiff> THAVAnd σdiff> THσIt is whether true;
As judgement AVdiff> THAVAnd σdiff> THσWhen establishment, it is determined with multipath, otherwise judges no multipath.
Optionally, the method further includes:
When being determined with multipath, diff_left_right_probability_filtered > Th are judgedmulWhether at
It is vertical;
As diff_left_right_probability_filtered > ThmulWhen establishment, it is determined as there is direct signal
Otherwise multi-path situation is determined as the multi-path situation of not direct signal.
Optionally, the diff values of the descriptor code relevant peaks distortion degree are distortion degree on the left of descriptor code relevant peaks
Diff_left and distortion degree on the right side of descriptor code relevant peaks diff_right's and.
Second aspect, the present invention provide a kind of multi-path detection device, including:
Acquiring unit, for obtaining current carrier-to-noise ratio CN0 and code relevant peaks;
First computing unit, for calculating the diff values for being used for descriptor code relevant peaks distortion degree under current carrier-to-noise ratio;
Storage unit, for storing the diff values and current carrier-to-noise ratio;
First judging unit, for judging whether the quantity of the diff values of the storage unit storage is more than predetermined value;
Second judgment unit, the quantity of the diff values for judging the storage unit storage when first judging unit
When no more than predetermined value, judge whether single diff values are more than the corresponding threshold values Th of current carrier-to-noise ratio;
Third judging unit, for judging that single diff values are corresponding more than current carrier-to-noise ratio when the second judgment unit
When threshold values Th, it is determined with multipath, otherwise judges no multipath;
4th judging unit, the quantity of the diff values for judging the storage unit storage when first judging unit
When more than predetermined value, multipath is judged whether according to diff Data-Statistics information.
Optionally, described device further includes:
Second computing unit calculates code phase after obtaining current carrier-to-noise ratio and code relevant peaks in the acquiring unit
There is the probability diff_left_ of difference diff_left_right between distortion and the right side distortion of code relevant peaks on the left of Guan Feng
right_probability;
Filter unit obtains diff_left_ for being filtered to diff_left_right_probability
right_probability_filtered。
Optionally, the 4th judging unit includes:
Computation subunit, for judging that the quantity of the diff values of the storage unit storage is big when first judging unit
When the predetermined value, the mean value AV of all diff values of storage is calculateddiffAnd variances sigmadiff, and all CN0 for being stored
Mean value AVCN0And variances sigmaCN0;
Determination subelement, for the mean value AV according to CN0CN0And variances sigmaCN0Determine threshold values THAVAnd THσ;
First judgment sub-unit, for judging AVdiff> THAVAnd σdiff> THσIt is whether true;
Second judgment sub-unit, for judging AV when first judgment sub-unitdiff> THAVAnd σdiff> THσIt sets up
When, it is determined with multipath, otherwise judges no multipath.
Optionally, described device further includes:
5th judging unit, for when second judgment sub-unit is determined with multipath, judging diff_left_
Right_probability_filtered > ThmulIt is whether true;
6th judging unit, for judging diff_left_right_probability_ when the 5th judging unit
Filtered > ThmulWhen establishment, it is determined as the multi-path situation for having direct signal, is otherwise determined as the multipath of not direct signal
Situation.
Optionally, the diff values of the descriptor code relevant peaks distortion degree are distortion degree on the left of descriptor code relevant peaks
Diff_left and distortion degree on the right side of descriptor code relevant peaks diff_right's and.
The third aspect, the present invention provide a kind of GNSS receiver, and the GNSS receiver includes above-mentioned multi-path detection device.
Multi-path detecting method, device and GNSS receiver provided in an embodiment of the present invention obtain current carrier-to-noise ratio CN0 and code
Relevant peaks calculate the diff values for being used for descriptor code relevant peaks distortion degree under current carrier-to-noise ratio, store diff values and current
Carrier-to-noise ratio, judges whether the quantity of the diff values of storage is more than predetermined value, if so, it is current to judge whether single diff values are more than
Otherwise the corresponding threshold values Th of carrier-to-noise ratio judges no multipath if so, being determined with multipath;When the quantity of the diff values of judgement storage
When more than predetermined value, multipath is judged whether according to diff Data-Statistics information.Compared with prior art, the present invention is based on code phases
Guan Feng is detected, and is not influenced by code loop bandwidth, by comparison be locally stored it is noiseless when code relevant peaks and actual code phase
The difference of Guan Feng carries out multipath detection, does not have information loss, can improve the reliability and precision of multipath detection;And it can
More accurately judged with being done to code correlation peak shape, distinguish the multipath type detected, to be more advantageous to sentencing for multi-path jamming
It is fixed.
Description of the drawings
Fig. 1 is the flow chart of one embodiment of the invention multi-path detecting method;
Fig. 2 is the flow chart of another embodiment of the present invention multi-path detecting method;
Fig. 3 is normal code relevant peaks and the code relevant peaks comparison schematic diagram by multi-path jamming;
Fig. 4 is the normal code relevant peaks obtained using (E-L)/(E+L) phase discriminators under 1/4 chip-spaced and is done by multipath
The comparison schematic diagram for the code relevant peaks disturbed;
Fig. 5 is the schematic diagram of the code relevant peaks by multi-path jamming as E and L unjustified;
Fig. 6 is to obtain the schematic diagram of the unjustified relevant peaks of E and L from ideal glitch-free relevant peaks;
Fig. 7 is carrier-to-noise ratio and measures the distribution trend figure of noise;
Fig. 8 is the structural schematic diagram of one embodiment of the invention multi-path detection device;
Fig. 9 is the structural schematic diagram of another embodiment of the present invention multi-path detection device.
Specific implementation mode
In order to make the object, technical scheme and advantages of the embodiment of the invention clearer, below in conjunction with the embodiment of the present invention
In attached drawing, technical scheme in the embodiment of the invention is clearly and completely described, it is clear that described embodiment is only
It is only a part of the embodiment of the present invention, instead of all the embodiments.Based on the embodiments of the present invention, ordinary skill
The every other embodiment that personnel are obtained without making creative work, shall fall within the protection scope of the present invention.
In general, when not by multi-path jamming, code relevant peaks are symmetrical, as shown in Fig. 3 (A).When by multi-path jamming, code is related
Peak is distorted, as shown in Fig. 3 (B).What Fig. 3 was provided is the overall picture of yard relevant peaks, and actual receiver can not possibly be accomplished so
High sample rate.The noiseless relevant peaks (Fig. 4 (A)) and the relevant peaks by multi-path jamming that Fig. 4 gives the sampling of 1/4 code interval
(Fig. 4 (B)).Fig. 4 (B) is it can be seen that the distortion of apparent code, and therefore, the shape of code relevant peaks is also relatively clearly under low sampling rate.
It, can be by comparing abnormal in the ideal relevant peaks and Fig. 4 (B) of Fig. 4 (A) due to (E=L) that E and L is in alignment in Fig. 4 (B)
Become the difference of relevant peaks, the degree of quantitative description distortion, as shown in formula (1), (2), (3).The bigger expression relevant peaks of diff values
The degree to be distorted is bigger, smaller to indicate closer to ideal relevant peaks.
Diff=diff_left+diff_right (3)
Wherein, P*Indicate the output of instant code correlator,
Indicate the output of advanced i 1/4 chip correlators,
Indicate the output of i 1/4 chip correlators of lag,
M indicates that the case where E and L is aligned, MB indicate E and L misaligned situations.
The embodiment of the present invention provides a kind of multi-path detecting method, as shown in Figure 1, the method includes:
S101, current carrier-to-noise ratio CN0 and code relevant peaks are obtained;
S102, the diff values for being used for descriptor code relevant peaks distortion degree under current carrier-to-noise ratio are calculated;
Wherein, the diff values of the descriptor code relevant peaks distortion degree are distortion degree diff_ on the left of descriptor code relevant peaks
Left and distortion degree on the right side of descriptor code relevant peaks diff_right's and.
S103, the diff values and current carrier-to-noise ratio are stored;
S104, judge whether the quantity of the diff values of storage is more than predetermined value;
S105, when judgement storage diff values quantity be not more than predetermined value when, judge single diff values whether be more than work as
Front bearing is made an uproar than corresponding threshold values Th;
S106, when judging that single diff values are more than the corresponding threshold values Th of current carrier-to-noise ratio, be determined with multipath, otherwise judge
Without multipath;
S107, when judgement storage diff values quantity be more than predetermined value when, judged whether according to diff Data-Statistics information
There are multipaths.
Wherein, the diff Data-Statistics information is the mean value and variance of diff values.
Multi-path detecting method provided in an embodiment of the present invention, obtains current carrier-to-noise ratio CN0 and code relevant peaks, and front bearing is worked as in calculating
It makes an uproar than the lower diff values for descriptor code relevant peaks distortion degree, stores the diff values and current carrier-to-noise ratio, judge storage
Whether the quantity of diff values is more than predetermined value, if so, judging whether single diff values are more than the corresponding threshold values of current carrier-to-noise ratio
Otherwise Th judges no multipath if so, being determined with multipath;When the quantity of the diff values of judgement storage is more than predetermined value, according to
Diff Data-Statistics information judges whether multipath.Compared with prior art, the present invention is based on code relevant peaks to detect, not by code
The influence of loop bandwidth, by comparison be locally stored it is noiseless when code relevant peaks and actual code relevant peaks difference it is more to carry out
Diameter detects, and does not have information loss, can improve the reliability and precision of multipath detection;And code correlation peak shape can be done
More accurately judge, distinguish the multipath type detected, to be more advantageous to the judgement of multi-path jamming.
The embodiment of the present invention provides another multi-path detecting method, as shown in Fig. 2, the method includes:
S201, current carrier-to-noise ratio (CN0) and code relevant peaks are obtained.
S202, the diff values that code relevant peaks are calculated according to following formula:
For most of receivers, code ring is exactly using E and L phase demodulations, the difference very little or equal of usual E and L, Fig. 4 (B)
Such case.But also there is E and L to differ larger situation, as shown in Figure 5.In this case, related in order to measure code
The distortion degree at peak, it would be desirable to which relevant peaks, which are done, to be changed, its E and L are transformed to situation not etc., compare the ideal code phase after transformation
Guan Feng and code relevant peaks to be measured.Detailed process is as follows:
First, relevant peaks E to be measured and L deviations are calculated, such as formula (4)
Then, according to the ideal relevant peaks F of Fig. 6 (A)ideal_profile(x), a point a can be found to makeEqual to Δ.
Therefore, from ideal relevant peaks Fig. 6 (A) can be converted after relevant peaks Fig. 6 (B), wherein
PB=Fideal_profile(a),
Wherein, Fideal_profile(x) indicate that the ideal relevant peaks in Fig. 6 (A), x value ranges are [- 4,4], unit 1/
4 chips.
In fact, Δ and a have one-to-one relationship, from ideal relevant peaks Fideal_profile(x) function V can be found out
(x) so that V (Δ)=a.Wherein, ideal relevant peaks are different under different carrier-to-noise ratios, and carrier-to-noise ratio difference is bigger, the difference of ideal relevant peaks
It is different also bigger.So under a certain carrier-to-noise ratio, by Fideal_profile(CN0, x) obtains specific V (CN0, x).Therefore, there are public affairs
Formula (5), (6), (7):
PB=Fideal_profile(V(CN0,Δ)) (5)
Wherein, Fideal_profile(CN0, x) indicates the ideal relevant peaks under carrier-to-noise ratio CN0.
The diff values of code relevant peaks are calculated according to following formula (8), (9), (10):
Diff=diff_left+diff_right (10)
S203, storage diff values and CN0.
S204, judge whether the data volume of storage is enough, if the data volume of storage is insufficient, then follow the steps S205, it is no
Then follow the steps S209.
S205, threshold values Th is selected according to CN0 (i).
S206, judge whether diff values are more than selected threshold values Th and otherwise judge no multipath if so, being determined with multipath.
Specifically, by diff values compared with threshold values, if it exceeds threshold values is then judged as there is multi-path jamming, otherwise it is judged as not having
There is multi-path jamming.It is noted herein that under different carrier-to-noise ratios, threshold values is different.Due to the presence of noise, even if phase
For Guan Feng not by multi-path jamming, diff metrics will not be 0, but the Gaussian Profile that a mean value is 0.Noise is bigger,
Variance is bigger.Fig. 7 gives under no multi-path jamming, the relationship of CN0 and diff metrics.For different receivers, due to
The difference of radio-frequency front-end and processing procedure, the concrete numerical value in Fig. 7 are different, and need to obtain by actual measurement.It obtains in Fig. 7
After particular number relationship, threshold values, such as 3 σ rules can be set according to desired detection and false alarm rate.
There is the probability diff_left_right_probability of diff_left_right in S207, calculating.
Specifically, statistics is under different carrier-to-noise ratios and without multi-path jamming in advance, the mean value of diff_left_right
μdiff_left_right(CN0) and variances sigmadiff_left_right(CN0), wherein diff_left_right is counted according to following formula (11)
It calculates:
Diff_left_right=diff_left-diff_right (11)
Calculate the poor diff_left_right of the diff_left and diff_right at current CN0;
According at current CN0, mean μ that when no multi-path jamming countsdiff_left_right(CN0) and variance
σdiff_left_right(CN0), the probability diff_left_ for diff_left_right occur is calculated according to following formula (12)
right_probability:
Wherein, error function
S208, diff_left_right_probability is filtered according to following formula (13), obtains diff_
left_right_probability_filtered。
diff_left_right_probability_filteredn=(1- α) diff_left_right_
probability_filteredn-1+α·diff_left_right_probabilityn
(13)
Wherein, [0,1] α ∈.
S209, the mean value AV for calculating diffdiffAnd variances sigmadiff, the mean value AV of CN0CN0And variances sigmaCN0。
S210, the mean value AV according to CN0CN0And variances sigmaCN0Selected threshold values THAVAnd THσ。
S211, judge whether to meet AVdiff> THAVAnd σdiff> THσ, if so, being determined with multipath, and execute step
S212, if it is not, then judgement is without multipath.
S212, judge whether to meet diff_left_right_probability_filtered > Thmul, if so, sentencing
Being set to has the multi-path situation of direct signal, otherwise, it is determined that for the multi-path situation of not direct signal.
Wherein, Th can be set according to desired detection and false alarm rate.
Multi-path jamming can rough segmentation be two classes, one kind is that direct signal accounts for leading role, and reflection signal is weaker than direct signal;The
Two classes are that direct signal is not present, though only reflect signal or direct signal exist it is weaker than reflecting signal.Comparatively,
Error bigger caused by second class multi-path situation.To first kind situation, since reflection signal is always more late than direct signal and it compares
Direct signal is weak, therefore the distortion that right one side of something of code relevant peaks is subject to is half of bigger than left;Similar, in the second class situation, code
The distortion that left one side of something of relevant peaks is subject to is half of bigger than right.It therefore can be by comparing the size of diff_left and diff_right
To judge which kind of multi-path jamming belongs to.
The embodiment of the present invention also provides a kind of multi-path detection device, as shown in figure 8, described device includes:
Acquiring unit 101, for obtaining current carrier-to-noise ratio CN0 and code relevant peaks;
First computing unit 102, for calculating the diff values for being used for descriptor code relevant peaks distortion degree under current carrier-to-noise ratio;
Storage unit 103, for storing the diff values and current carrier-to-noise ratio;
First judging unit 104, for judging it is predetermined whether the quantity of the diff values of the storage of the storage unit 103 is more than
Value;
Second judgment unit 105, for judging what the storage unit 103 stored when first judging unit 104
When the quantity of diff values is not more than predetermined value, judge whether single diff values are more than the corresponding threshold values Th of current carrier-to-noise ratio;
Third judging unit 106, for judging that single diff values are more than current carrier-to-noise ratio when the second judgment unit 105
When corresponding threshold values Th, it is determined with multipath, otherwise judges no multipath;;
4th judging unit 107, for judging what the storage unit 103 stored when first judging unit 104
When the quantity of diff values is more than predetermined value, multipath is judged whether according to diff Data-Statistics information.
Further, as shown in figure 9, described device further includes:
Second computing unit 108, after obtaining current carrier-to-noise ratio and code relevant peaks in the acquiring unit 101, meter
It calculates on the left of code relevant peaks and the probability diff_ of difference diff_left_right occurs between distortion and the right side distortion of code relevant peaks
left_right_probability;
Filter unit 109 obtains diff_left_ for being filtered to diff_left_right_probability
right_probability_filtered。
Further, as shown in figure 9, the 4th judging unit 107 includes:
Computation subunit 1071, for judging the diff that the storage unit 103 stores when first judging unit 104
When the quantity of value is more than the predetermined value, the mean value AV of all diff values of storage is calculateddiffAnd variances sigmadiff, and stored
All CN0 mean value AVCN0And variances sigmaCN0;
Determination subelement 1072, for the mean value AV according to CN0CN0And variances sigmaCN0Determine threshold values THAVAnd THσ;
First judgment sub-unit 1073, for judging AVdiff> THAVAnd σdiff> THσIt is whether true;
Second judgment sub-unit 1074, for judging AV when first judgment sub-unit 1073diff> THAVAnd σdiff>
THσWhen establishment, it is determined with multipath, otherwise judges no multipath.
Further, as shown in figure 9, described device further includes:
5th judging unit 110, for when second judgment sub-unit 1074 is determined with multipath, judging diff_
Left_right_probability_filtered > ThmulIt is whether true;
6th judging unit 111, for judging diff_left_right_ when the 5th judging unit 110
Probability_filtered > ThmulWhen establishment, it is determined as the multi-path situation for having direct signal, is otherwise determined as without straight
Up to the multi-path situation of signal.
Optionally, the diff values of the descriptor code relevant peaks distortion degree are distortion degree on the left of descriptor code relevant peaks
Diff_left and distortion degree on the right side of descriptor code relevant peaks diff_right's and.
Multi-path detection device provided in an embodiment of the present invention, obtains current carrier-to-noise ratio CN0 and code relevant peaks, and front bearing is worked as in calculating
It makes an uproar than the lower diff values for descriptor code relevant peaks distortion degree, stores the diff values and current carrier-to-noise ratio, judge storage
Whether the quantity of diff values is more than predetermined value, if so, judging whether single diff values are more than the corresponding threshold values of current carrier-to-noise ratio
Otherwise Th judges no multipath if so, being determined with multipath;When the quantity of the diff values of judgement storage is more than predetermined value, according to
Diff Data-Statistics information judges whether multipath.Compared with prior art, the present invention is based on code relevant peaks to detect, not by code
The influence of loop bandwidth, by comparison be locally stored it is noiseless when code relevant peaks and actual code relevant peaks difference it is more to carry out
Diameter detects, and does not have information loss, can improve the reliability and precision of multipath detection;And code correlation peak shape can be done
More accurately judge, distinguish the multipath type detected, to be more advantageous to the judgement of multi-path jamming.
The device of the present embodiment can be used for executing the technical solution of above method embodiment, realization principle and technology
Effect is similar, and details are not described herein again.
The embodiment of the present invention also provides a kind of GNSS receiver, and the GNSS receiver includes above-mentioned multi-path detection device.
One of ordinary skill in the art will appreciate that realizing all or part of flow in above-described embodiment method, being can be with
Relevant hardware is instructed to complete by computer program, the program can be stored in a computer read/write memory medium
In, the program is when being executed, it may include such as the flow of the embodiment of above-mentioned each method.Wherein, the storage medium can be magnetic
Dish, CD, read-only memory (Read-Only Memory, ROM) or random access memory (Random Access
Memory, RAM) etc..
The above description is merely a specific embodiment, but scope of protection of the present invention is not limited thereto, any
Those familiar with the art in the technical scope disclosed by the present invention, all answer by the change or replacement that can be readily occurred in
It is included within the scope of the present invention.Therefore, protection scope of the present invention should be subject to the protection scope in claims.
Claims (11)
1. a kind of multi-path detecting method, which is characterized in that including:
Obtain current carrier-to-noise ratio CN0 and code relevant peaks;
Calculate the diff values for being used for descriptor code relevant peaks distortion degree under current carrier-to-noise ratio;
Store the diff values and current carrier-to-noise ratio;
Judge whether the quantity of the diff values of storage is more than predetermined value;
When the quantity of the diff values of judgement storage is not more than predetermined value, judge whether single diff values are more than current carrier-to-noise ratio pair
The threshold values Th answered;
As judgement single diff values threshold values Th corresponding more than current carrier-to-noise ratio, it is determined with multipath, otherwise judges no multipath;
When the quantity of the diff values of judgement storage is more than predetermined value, multipath is judged whether according to diff Data-Statistics information.
2. according to the method described in claim 1, it is characterized in that, it is described obtain current carrier-to-noise ratio and code relevant peaks after,
The method further includes:
It calculates on the left of code relevant peaks and the probability of difference diff_left_right occurs between distortion and the right side distortion of code relevant peaks
diff_left_right_probability;
Diff_left_right_probability is filtered, diff_left_right_probability_ is obtained
filtered。
3. according to the method described in claim 2, it is characterized in that, it is described judged whether according to diff Data-Statistics information it is more
Diameter includes:
Calculate the mean value AV of all diff values of storagediffAnd variances sigmadiff, and the mean value AV of all CN0 that is storedCN0With
Variances sigmaCN0;
According to the mean value AV of CN0CN0And variances sigmaCN0Determine threshold values THAVAnd THσ;
Judge AVdiff> THAVAnd σdiff> THσIt is whether true;
As judgement AVdiff> THAVAnd σdiff> THσWhen establishment, it is determined with multipath, otherwise judges no multipath.
4. according to the method described in claim 3, it is characterized in that, the method further includes:
When being determined with multipath, diff_left_right_probability_filtered > Th are judgedmulIt is whether true;
As diff_left_right_probability_filtered > ThmulWhen establishment, it is determined as the multipath for having direct signal
Otherwise situation is determined as the multi-path situation of not direct signal.
5. according to the method described in claim 1, it is characterized in that, the diff values of the descriptor code relevant peaks distortion degree are to retouch
State on the left of yard relevant peaks distortion degree diff_left and distortion degree on the right side of descriptor code relevant peaks diff_right's and.
6. a kind of multi-path detection device, which is characterized in that including:
Acquiring unit, for obtaining current carrier-to-noise ratio CN0 and code relevant peaks;
First computing unit, for calculating the diff values for being used for descriptor code relevant peaks distortion degree under current carrier-to-noise ratio;
Storage unit, for storing the diff values and current carrier-to-noise ratio;
First judging unit, for judging whether the quantity of the diff values of the storage unit storage is more than predetermined value;
Second judgment unit, for judging that the quantity of the diff values of the storage unit storage is little when first judging unit
When predetermined value, judge whether single diff values are more than the corresponding threshold values Th of current carrier-to-noise ratio;
Third judging unit, for being more than the corresponding threshold values of current carrier-to-noise ratio when second judgment unit judgement single diff values
When Th, it is determined with multipath, otherwise judges no multipath;
4th judging unit, for judging that the quantity of the diff values of the storage unit storage is more than when first judging unit
When predetermined value, multipath is judged whether according to diff Data-Statistics information.
7. device according to claim 6, which is characterized in that described device further includes:
Second computing unit calculates code relevant peaks after obtaining current carrier-to-noise ratio and code relevant peaks in the acquiring unit
Left side is distorted there is the probability diff_left_right_ of difference diff_left_right between the right side distortion of code relevant peaks
probability;
Filter unit obtains diff_left_right_ for being filtered to diff_left_right_probability
probability_filtered。
8. device according to claim 7, which is characterized in that the 4th judging unit includes:
Computation subunit, for judging that the quantity of the diff values of the storage unit storage is more than institute when first judging unit
When stating predetermined value, the mean value AV of all diff values of storage is calculateddiffAnd variances sigmadiff, and the mean value of all CN0 that is stored
AVCN0And variances sigmaCN0;
Determination subelement, for the mean value AV according to CN0CN0And variances sigmaCN0Determine threshold values THAVAnd THσ;
First judgment sub-unit, for judging AVdiff> THAVAnd σdiff> THσIt is whether true;
Second judgment sub-unit, for judging AV when first judgment sub-unitdiff> THAVAnd σdiff> THσWhen establishment, sentence
Surely there is multipath, otherwise judge no multipath.
9. device according to claim 8, which is characterized in that described device further includes:
5th judging unit, for when second judgment sub-unit is determined with multipath, judging diff_left_right_
Probability_filtered > ThmulIt is whether true;
6th judging unit, for judging diff_left_right_probability_ when the 5th judging unit
Filtered > ThmulWhen establishment, it is determined as the multi-path situation for having direct signal, is otherwise determined as the multipath of not direct signal
Situation.
10. device according to claim 6, which is characterized in that the diff values of the descriptor code relevant peaks distortion degree are
On the left of descriptor code relevant peaks distortion degree diff_left and distortion degree on the right side of descriptor code relevant peaks diff_right's and.
11. a kind of GNSS receiver, which is characterized in that the GNSS receiver includes such as any one of claim 6 to 10 institute
The multi-path detection device stated.
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