CN108089162A - A kind of detection of pulse interference signal and suppressing method - Google Patents

Abstract

Detection and suppressing method the present invention provides a kind of pulse interference signal, the presence or absence of impulse disturbances are judged first, it calculates carrying out AF panel thresholding there are disturbed condition, inhibition processing is carried out to interference of the time-domain sampling signal amplitude beyond threshold value, reach AF panel purpose, artificial or unintentionally influence of the pulse interference signal for reception signal is reduced, while can be that relevant device product currently in use carries out early warning in environment.

Description

Method for detecting and inhibiting pulse interference signal

Technical Field

The invention belongs to the field of satellite navigation anti-interference.

Background

In some high-precision navigation or test platforms, the requirement on environment goodness is high, and the influence is not expected. It is desirable to be able to be prompted and warned if there is interference in the environment. The existing method based on energy accumulation detection and the existing detection method based on spectrum analysis have good detection effect on steady-state interference, but have poor detection effect on interference signals with extremely short time, and can not be found, so that false alarm can occur.

Disclosure of Invention

In order to overcome the defects of the prior art, the invention provides a method for detecting and suppressing a pulse interference signal, which can judge whether the pulse interference exists or not, calculate an interference suppression threshold when the interference exists, suppress the interference of a time domain sampling signal amplitude exceeding the threshold value, achieve the purpose of interference suppression, reduce the influence of artificial or unintentional pulse interference signals on received signals, and simultaneously can perform early warning on related equipment products in use in the environment.

The technical scheme adopted by the invention for solving the technical problem comprises the following steps:

step 1, sampling data, wherein the number of sampling points is n, n is more than or equal to 1000, and performing point-by-point difference processing on a sampling time domain signal and a mean value thereof to obtain a time domain signal x without a direct current component_r，r＝1，2，…，n；

Step 2, carrying out equal-length segmentation on the time domain signal without the direct current component, wherein the number of the segments is N, and N is more than or equal to 10 and less than or equal to N/100;

step 3, calculating the standard deviation of each section of time domain data in sequenceWherein,is the average of the ith segment of data, i 1, 2.., N; a is the number of sampling points in each segment of time domain data, and j is 1, 2.

Step 4, for sigma_iSorting from small to large to obtain data y_i，i＝1，2，...，N；

Step 5, recording a counting variable as k, wherein k is 2, 3, and N, and taking an initial value of k as 2;

step 6, calculating y_iThe mean and standard deviation of the first k data are respectivelyAnd Δ y, order

Step 7, if y_k+1≤L₀If k is less than N-1, adding 1 to the value of k, and repeating the step 6 and the step 7; if y_k+1≤L₀And k is N-1, or y_k+1＞L₀If so, stopping searching and taking the threshold as L₀Entering step 8;

step 8, according to the threshold L₀Statistic of σ_iThe number m of the middle is larger than the threshold; if m is 0, determining that no impulse interference exists in the environment; if m is larger than 0, determining that pulse interference exists in the environment, wherein the duty ratio of the pulse interference is m/N;

step 9, according to the doorLimit of L₀Searching a data segment without interference influence, and calculating the standard deviation delta of all data in the data segment;

step 10, the threshold value of interference suppression is marked as L₁The output signal after the interference suppression processing is denoted as z when the interference suppression threshold is 2.5 δ_r(ii) a For time domain signal x_rThe absolute value of (a): if x_r|≤L₁Then z is_r＝x_r(ii) a If x_r|＞L₁Then z is_r＝0。

The invention has the beneficial effects that:

1. the pulse jump of the time domain signal can be detected in time by a sectional processing mode, the short-time pulse has a good detection effect, the requirement on signal energy is not high, and the false alarm is not easy to miss.

2. The ambiguity of pulse interference duty ratio detection is not more than 1/N, and the larger the N value is, the more accurate the duty ratio judgment is.

3. The decision of the pulse suppression threshold value can change along with the change of the signal, but not a fixed criterion threshold, and the method has good adaptability to different noise environments.

Drawings

FIG. 1 is a schematic diagram of a time domain waveform of a sampled signal;

FIG. 2 is a signal diagram without a DC component;

FIG. 3 is a standard differential graph for each data segment;

FIG. 4 is a schematic diagram of the standard deviation sorted from small to large;

FIG. 5 is a graphical illustration of the relationship between the magnitude of a data value and a threshold value;

fig. 6 is a signal diagram after interference suppression.

Detailed Description

The present invention will be further described with reference to the following drawings and examples, which include, but are not limited to, the following examples.

The method comprises the following steps:

step 1: sampling data, wherein the number of sampling points is n, wherein n is more than or equal to 1000, and performing point-by-point difference processing on the sampling time domain signal and the mean value thereof to obtain a time domain signal x without a direct current component_i，i＝1，2，...，n；

Step 2: for data x_iAnd (3) carrying out equal-length segmentation, wherein the number of the segments is N, and N is more than or equal to 10 and less than or equal to N/100.

And step 3: calculating the standard deviation sigma of each section of time domain data in turn_i，

Wherein,is the average of the ith segment of data, i 1, 2.., N; a is the number of sampling points in each time domain data, and j is 1, 2.

And 4, step 4: to sigma_iSorting from small to large to obtain y_i，i＝1，2，...，N；

And 5: counting variables are recorded as k, k is 2, 3, and N, and an initial value of k is 2;

step 6: calculating y_iThe mean and standard deviation of the first k data of (1) areAnd Δ y, order

And 7: if y_k+1≤L₀And k < N-1, let k be k +1, repeat steps 6 and 7.

If y_k+1≤L₀And k is N-1, or y_k+1＞L₀If so, stopping searching and taking the threshold as L₀Entering step 8;

and 8: according to a threshold L₀Statistic of σ_iThe number m of the middle is larger than the threshold. If m is 0, determining that no impulse interference exists in the environment; if m is larger than 0, determining that impulse interference exists in the environment, and the duty ratio of the impulse interference is m/N.

And step 9: according to a threshold L₀And searching data sections without interference influence, and calculating the standard deviation delta of all data in the data sections.

Step 10: the threshold value for interference suppression is denoted as L₁Taking L₁2.5 delta is taken as the interference suppression threshold. The output signal after the interference suppression process is denoted as z_i，i＝1，2，...，n。

Step 11: for time domain signal x_iThe absolute value of (a): if x_i|≤L₁Then z is_i＝x_i(ii) a If x_i|＞L₁Then z is_i＝0。

In the embodiment of the invention, a broadband wave pulse signal is generated by a signal radio frequency signal source, the pulse period is 1 millisecond, and the duty ratio is 10%. The sampling is performed with a 62MHz sampling rate AD and the time domain signal waveform is obtained as shown in fig. 1.

Step 1: the sampling point number of the data is 62000, the sampling time domain signal and the average value thereof are subjected to point-by-point difference processing to obtain a time domain signal x without a direct current component_iAs shown in fig. 2.

Step 2: for data x_iEqual-length segmentation is carried out, and the number of segments is 100.

And step 3: calculating the standard deviation sigma of each section of time domain data in turn_i1., 100 as shown in fig. 3.

And 4, step 4: to sigma_iSorting from small to large to obtain y_i1., 100 as shown in fig. 4.

And 5: counting variables are recorded as k, k is 2, 100, and the initial value of k is 2;

step 6: calculating y_iThe mean and standard deviation of the first k data of (1) areAnd Δ y, order

And 7: if y_k+1≤L₀And k < 99, let k be k +1, repeat steps 6 and 7.

If y_k+1≤L₀And k is 99, or y_k+1＞L₀If so, stopping searching and taking the threshold as L₀Entering step 8;

through the iterative calculation steps 6-7, the following results are obtained: threshold L₀44.35. The relationship between the magnitude of the data value and the threshold value is shown in fig. 5.

And 8: according to a threshold L₀Statistic of σ_iThe number m of the middle is larger than the threshold.

Counting: m is 11; the duty ratio is calculated to be m/N, which is 11%.

And step 9: according to a threshold L₀And searching data sections without interference influence, and calculating the standard deviation delta of all data in the data sections.

The calculation results show that: δ 38.78;

step 10: interference suppression threshold value L₁＝296.95 with the interference suppression output noted z_i。

Step 11: for time domain signal x_iThe absolute value of (a): if x_iIf | is less than or equal to 96.95, z is_i＝x_i(ii) a If x_iIf | is greater than 96.95, then z_i0; thereby enabling the output z after interference suppression_iThe curve of (a) is shown in fig. 6.

Claims (1)

1. A method for detecting and suppressing a pulse interference signal is characterized by comprising the following steps:

step 1, sampling data, wherein the number of sampling points is n, n is more than or equal to 1000, and performing point-by-point difference processing on a sampling time domain signal and a mean value thereof to obtain a time domain signal x without a direct current component_r，r＝1,2,…,n；

Step 2, carrying out equal-length segmentation on the time domain signal without the direct current component, wherein the number of the segments is N, and N is more than or equal to 10 and less than or equal to N/100;

step 3, calculating the standard deviation of each section of time domain data in sequenceWherein,is the average of the ith segment of data, i 1, 2.., N; a is the number of sampling points in each segment of time domain data, and j is 1, 2.

Step 4, for sigma_iSorting from small to large to obtain data y_i，i＝1，2，...，N；

Step 5, recording a counting variable as k, wherein k is 2, 3, and N, and taking an initial value of k as 2;

step 6, calculating y_iThe mean and standard deviation of the first k data are respectivelyAnd Δ y, order

Step 7, if y_k+1≤L₀If k is less than N-1, adding 1 to the value of k, and repeating the step 6 and the step 7; if y_k+1≤L₀And k is N-1, or y_k+1＞L₀If so, stopping searching and taking the threshold as L₀Entering step 8;

step 8, according to the threshold L₀Statistic of σ_iThe number m of the middle is larger than the threshold; if m is 0, determining that no impulse interference exists in the environment; if m is larger than 0, determining that pulse interference exists in the environment, wherein the duty ratio of the pulse interference is m/N;

step 9, according to the threshold L₀Searching a data segment without interference influence, and calculating the standard deviation delta of all data in the data segment;

step 10, the threshold value of interference suppression is marked as L₁The output signal after the interference suppression processing is denoted as z when the interference suppression threshold is 2.5 δ_r(ii) a For time domain signal x_rThe absolute value of (a): if x_r|≤L₁Then z is_r＝x_r(ii) a If x_r|＞L₁Then z is_r＝0。