阅读说明：本技术 一种小范围重频抖动信号的谐波抑制方法 (Harmonic suppression method for small-range repetition frequency jitter signal ) 是由 田田 韩向清 匡华星 于 2020-06-12 设计创作，主要内容包括：本发明属于雷达数据处理及信号分选技术领域,特别涉及一种小范围重频抖动信号的谐波抑制方法,主要解决小范围重频抖动信号的谐波被误分选为重频固定信号的问题；其实现步骤是：1.遍历输入脉冲缓存并进行到达时间差直方图统计,记录所有过门限的直方图小箱；2.对于每个过门限的小箱k,PRI值标识为p<Sub>k</Sub>,寻找对应PRI值为<Image he="133" wi="125" file="DDA0002536242340000011.GIF" imgContent="drawing" imgFormat="GIF" orientation="portrait" inline="no"></Image>的直方图小箱r,获取小箱r相邻m个小箱范围内的直方图统计值分布并求和；3.依次计算N不同取值的情形,若任一情形下的直方图统计值分布及求和同时满足重频抖动谐波判断条件,则判定小箱k对应的PRI值p<Sub>k</Sub>为重频抖动信号的谐波；本发明有利于提高信号分选准确率,可用于雷达侦测系统。(The invention belongs to the technical field of radar data processing and signal sorting, and particularly relates to a harmonic suppression method for a small-range repetition frequency jitter signal, which mainly solves the problem that the harmonic of the small-range repetition frequency jitter signal is mistakenly sorted into a repetition frequency fixed signal; the method comprises the following implementation steps: 1. traversing the input pulse buffer, carrying out arrival time difference histogram statistics, and recording all histogram bins which pass through a threshold; 2. for each bin k that crosses the threshold, the PRI value is identified as p k Find a corresponding PRI value of The histogram bin r, a histogram system for obtaining the range of m adjacent bins of the bin rEvaluating distribution and summing; 3. sequentially calculating the conditions of different values of N, and if the distribution and summation of the histogram statistical values in any condition simultaneously meet the judgment condition of the repetition frequency jitter harmonic wave, judging the PRI value p corresponding to the small box k k Is a harmonic of the re-frequency jittered signal; the invention is beneficial to improving the signal sorting accuracy and can be used for a radar detection system.)

1. A harmonic suppression method for a small-range re-frequency jittered signal, comprising the steps of:

step 1: traversing the input pulse buffer, calculating the arrival time difference of any two pulses and carrying out histogram statistics, and recording the histogram statistical value v of each histogram small box k passing the threshold_kAnd a corresponding PRI value p_k；

Step 2: for each bin k that crosses the threshold, find the histogram bin r to have a corresponding PRI value of

And step 3: for the threshold-crossing small box k, the conditions of different values of N are sequentially calculated, the corresponding histogram small box r is obtained, and if any condition is met, the following two conditions are simultaneously met: (1) v. of_sum*β＞v_kWherein beta is more than 0 and less than or equal to 1; (2) small box r is center [ r-m, r + m]Histogram statistic value of q small boxes in all small boxes in range is greater than or equal to threshold value v_thrWherein q is not less than 2, v_thrNot less than 1; then the PRI value p corresponding to the threshold-crossing small box k is determined_kIs a harmonic of the re-frequency jittered signal.

2. A method for harmonic suppression of a small-range re-frequency jittered signal according to claim 1, wherein the step 1 comprises:

(1.1) for any two pulses, calculating the arrival time difference dtoa and the small box b to which the histogram statistic belongs,wherein tau is_minIs the minimum of the PRI range of interest to the signal sorting algorithm, x is the bin width; adding one to the histogram statistic of the small box b;

(1.2) traversing the input pulse buffer, and repeating the steps until the traversal is finished;

(1.3) for the small box b, calculate the threshold value

(1.4) recording all histogram bins with histogram statistic values greater than a threshold value, wherein for each histogram bin k with a threshold crossing, the histogram statistic values are represented by v_kIndicates, the corresponding PRI value p_kIt is shown that,

3. a method for harmonic suppression of a small-range re-frequency jittered signal according to claim 1 or claim 2, wherein the step 2 comprises:

(2.1) for each histogram bin k of the threshold crossing, setting the corresponding PRI value p_kFind a corresponding PRI value ofThe histogram of (a) is small in the bin r,wherein tau is_minIs the minimum of the PRI range of interest to the signal sorting algorithm, x is the bin width;

(2.2) look at [ r-m, r + m ] centered on the small box r]All histogram bins in the range, and using the histogram statistic value of each bin in the range as v_iRepresenting, calculating the sum of statistical values

Technical Field

The invention belongs to the technical field of radar data processing and signal sorting.

Background

The repeated frequency dithering signal is a kind of complex time domain modulation for radiation sourceThe time domain characteristics of the important manifestations can be expressed as follows: t is t_n＝t_n-1+p(1±_n) N-1, where p is the dither center and is the dither radius. When the value is small, for example, less than 5%, the signal is called a small-range jitter signal. Signal sorting of the re-frequency jittered signal is a difficult problem. In an actual environment, due to the mixed signal types and the existence of the repetition frequency fixed signal, the sorting accuracy of the dither signal is reduced, so a sorting flow of sorting the repetition frequency fixed signal first and then sorting the repetition frequency dither signal is generally adopted, that is, for the input mixed signal PDW data, the sorting process of the repetition frequency fixed signal is firstly performed, and the sorting process of the repetition frequency dither signal is performed on the residual PDW data.

However, for a small-range repetition frequency jitter signal, because the variation range of the pulse repetition interval is small, for example, only tens of microseconds or even tens of microseconds, the second or higher harmonic thereof has a certain probability of having a time domain characteristic similar to that of the repetition frequency fixed signal in a short time, and thus is mistakenly sorted into the repetition frequency fixed signal, and the sorting accuracy of the jitter signal is reduced. The existing harmonic suppression method can only deal with the situation that the original signal and the harmonic thereof belong to the same signal type. For a small range of re-frequency jittered signal, it is not well suppressed because the signal type of its harmonics may change. How to suppress the harmonic wave of the small-range re-frequency jitter signal and the missorting caused by the harmonic wave are an urgent problem to be solved.

Disclosure of Invention

The invention aims to provide a harmonic suppression method for a small-range repetition frequency jitter signal, which is used for judging the harmonic of a repetition frequency fixed signal generated by histogram statistical processing, eliminating the PRI value which is possibly the harmonic of the small-range repetition frequency jitter signal and improving the signal sorting accuracy.

In order to realize the technical purpose, the invention is realized by adopting the following steps:

step 1: traversing the input pulse buffer, calculating the arrival time difference of any two pulses and carrying out histogram statistics, and recording the histogram statistical value v of each histogram small box k passing the threshold_kAnd corresponding PRI valuesp_k；

Step 2: for each bin k that crosses the threshold, find the histogram bin r to have a corresponding PRI value of

Wherein N is a positive integer and N_min≤N≤N_maxObtaining [ r-m, r + m ] centered on the small box r]Histogram statistics of all bins within the range, m being a positive integer, and calculating a sum of the statistics, v_sum；

And step 3: for the threshold-crossing small box k, the conditions of different values of N are sequentially calculated, the corresponding histogram small box r is obtained, and if any condition is met, the following two conditions are simultaneously met: (1) v. of_sum*β＞v_kWherein beta is more than 0 and less than or equal to 1; (2) small box r is center [ r-m, r + m]Histogram statistic value of q small boxes in all small boxes in range is greater than or equal to threshold value v_thrWherein q is not less than 2, v_thrNot less than 1; then the PRI value p corresponding to the threshold-crossing small box k is determined_kIs a harmonic of the re-frequency jittered signal.

The invention has the beneficial effects that: aiming at the problem that the harmonic waves of the small-range repeated frequency jitter signals are possibly mistakenly sorted into the repeated frequency fixed signals during signal sorting, the repeated frequency fixed signals generated through histogram statistical processing are subjected to harmonic judgment, PRI values which are possibly the harmonic waves of the small-range repeated frequency jitter signals are eliminated, and the signal sorting accuracy is improved.

Drawings

FIG. 1 is a flow chart of an embodiment of the present invention.

Detailed Description

FIG. 1 is a flow chart of an embodiment of the present invention. With the attached drawings, the steps of the embodiment of the invention are as follows:

step 1: traversing the input pulse buffer, calculating the arrival time difference of any two pulses and carrying out histogram statistics, and recording the histogram statistical value v of each histogram small box k passing the threshold_kAnd a corresponding PRI value p_k；

(1.1) for any two pulses, calculating the arrival time difference dtoa and the small box b to which the histogram statistic belongs,

wherein tau is_minIs the minimum of the PRI range of interest to the signal sorting algorithm, x is the bin width; adding one to the histogram statistic of the small box b;

(1.2) traversing the input pulse buffer, and repeating the steps until the traversal is finished;

(1.3) for the small box b, calculate the threshold value

Wherein alpha is a weight coefficient, alpha is more than 0 and less than 1, T is observation time which is equal to the maximum value of the arrival time difference of any two pulses in the input pulse buffer, tau is a PRI value corresponding to the small box b,

(1.4) recording all histogram bins with histogram statistic values greater than a threshold value, wherein for each histogram bin k with a threshold crossing, the histogram statistic values are represented by v_kIndicates, the corresponding PRI value p_kIt is shown that,

step 2: for each bin k that crosses the threshold, find the histogram bin r to have a corresponding PRI value ofWherein N is a positive integer and N_min≤N≤N_maxObtaining [ r-m, r + m ] centered on the small box r]Histogram statistics of all bins within the range, m being a positive integer, and calculating a sum of the statistics, v_sum；

(2.1) for each histogram bin k of the threshold crossing, setting the corresponding PRI value p_kFind a corresponding PRI value ofThe histogram of (a) is small in the bin r,

wherein tau is_minIs the minimum of the PRI range of interest to the signal sorting algorithm, x is the bin width;

(2.2) look at [ r-m, r + m ] centered on the small box r]All histogram bins in the range, and using the histogram statistic value of each bin in the range as v_iRepresenting, calculating the sum of statistical values

And step 3: for the threshold-crossing small box k, the conditions of different values of N are calculated in sequence, the corresponding histogram small box r is obtained, and if the following two conditions are simultaneously met in any condition, the PRI value p corresponding to the small box k is judged_kHarmonics of the re-frequency jittered signal:

(1)v_sum*β＞v_kwherein beta is more than 0 and less than or equal to 1;

(2) small box r is center [ r-m, r + m]Histogram statistic value of q small boxes in all small boxes in range is greater than or equal to threshold value v_thrWherein q is not less than 2, v_thrIf the value is more than or equal to 1, judging the PRI value p corresponding to the small threshold box k_kIs a harmonic of the re-frequency jittered signal.