CN106932761A - A kind of cognition perseverance mould waveform design method of antinoise signal dependent form interference - Google Patents

Abstract

The invention discloses a kind of cognition perseverance mould waveform design method of antinoise signal dependent form interference, belong to Anti-jamming Technology for Radar field, its more particularly to Waveform Design and interference mitigation technology field.Existing anti-clutter, the Waveform Design criterion function of electronic interferences are mostly based on detection probability, signal to noise ratio etc., and the interference for different delay needs to redesign waveform, and forward type interference when can not suppress fast.The method that the present invention suppresses the interference of faster slower relay type SD types using the Waveform Design mode of subpulse phase-modulation in arteries and veins.First, interference suppression signal model is set up using the thought for suppressing cross-correlation between interference signal and transmission signal, consider to suppress signal autocorrelation side lobe levels simultaneously on the basis of interference is suppressed, and consider permanent modular constraint, then for the target problem function set up, it is proposed that a kind of optimal minimum iterative search optimized algorithm carries out abbreviation solution.The method can well suppress the interference of SD types and can keep the radar detection requirement of low sidelobe.

Description

A kind of cognition perseverance mould waveform design method of antinoise signal dependent form interference

Technical field

The invention belongs to Anti-jamming Technology for Radar field, its more particularly to Waveform Design and interference mitigation technology field.

Background technology

In modern war, the electromagnetic environment that radar system faces is increasingly complicated, such as city, mountain region land clutter, replicates Decoy electronic deception etc..Signal dependent form (Signal-Dependent, SD) interference is that linear correlation is closed in itself with signal The one class interference of system, such as SMSP (SMeared SPectrum) range gate deception electronic interferences, jammer replicates thunder by intercepting and capturing SMSP interference is constituted up to transmission signal and be transmitted to radar receiver, cause radar matched filtering to occur many falseness mesh after detecting Mark, the severe jamming normal detection operations of radar.Therefore radar system is improved significant to suppression that SD types are disturbed.

Waveform agility technique by the free degree such as real-time regulation waveform coding, pulsewidth, spectrum distribution, power design with it is specific The waveform that detection environment matches, can effectively improve radar under complex environment to the detection performance of target.By waveform agile Technology is applied to Radar cross-section redaction has turned into current research focus.The Waveform Design criterion letter of existing anti-clutter, electronic interferences Number be mostly detection probability, letter it is dry/it is miscellaneous/make an uproar than (Signal-Interference/Clutter/Noise Ratio, SICNR), Integration sidelobe level (Integrated Sidelobe Level, ISL) and information KL (Kullback-Leibler) divergence etc., Waveform must be redesigned for different delay or multiple disturbed conditions, waveform utilization rate is reduced.And when can not suppress fast Forward type is disturbed, i.e., the interference of forwarding within a pulse repetition period (Pulse Repetition Period, PRT).For This, the present invention proposes a kind of faster slower relay type SD types that suppress and does using the Waveform Design mode of subpulse phase-modulation in arteries and veins The method disturbed.

The content of the invention

In order to suppress the interference of faster slower relay type signal dependent form, waveform autocorrelation sidelobe level is forced down, realize radar system To the effective detection of weak target, the invention provides a kind of cognition perseverance mould waveform design method of antinoise signal dependent form interference.

The present invention be divided into set up optimization problem modeling and waveform optimization solve two stages.Setting up optimization problem modeling rank Section, the method is first on the basis of cognitive SD disturbs specific modulation format, it is considered to a series of sub-pulses for intra-pulse modulation, if Meter criterion is as follows：1) cross-correlation level is reduced between interference signal and radar emission signal to realize suppressing interference signal；2) reduce The integration auto-correlation level of radar emission signal is forcing down sidelobe level.Furthermore, it is contemplated that radar emission is full with reception system With power service condition, to design waveform increased permanent mould (i.e. constant amplitude) constraints.Based on criterion above and about Beam condition, sets up optimization problem model.In the waveform optimization design phase, the method is directed to the four-dimensional optimization set up on last stage and asks Topic propose a kind of optimal minimum iterative search (Majorization-Minimization Iteration Search, MMIS) optimized algorithm carries out abbreviation solution.The waveform that the method is obtained can well suppress the interference of SD types and can keep low The radar detection requirement of secondary lobe.

The technical scheme is that a kind of cognition perseverance mould waveform design method of antinoise signal dependent form interference, the method bag Include：

Step 1, initiation parameter：

Initialization system parameter includes：Subpulse number N in arteries and veins, sets initial perseverance mould transmission signal s₀, s=[s₁, ...s_n,...,s_N] it is radar emission signal, whereinWherein φ_nIt is s₀N-th subpulse Phase code；Interference signal transfer matrix J_c, then interference echo signal is c=J_cS, iteration convergence coefficient ε₁, ε₂；

Step 2, set up optimization problem Mathematical Modeling：

2.1st, set up to reduce and cross-correlation level ICSL (Integrated are integrated between interference signal and radar emission signal Cross-correlation Sidelobe Level)：

Wherein, ()^HRepresent conjugate transposition,It is mapping matrix, k={ 0,1 ..., N-1 } is represented and prolonged Count late；

2.2nd, the integration auto-correlation level of radar emission signal is set up to force down integration sidelobe level IASL (Integrated Auto-correlation Sidelobe Level)：

2.3rd, the criterion function according to 2.1,2.2 sets up following problem model：

Step 3, for problem P₁Solving-optimizing waveform：

3.1st, abbreviation P first₁Optimization problem be：

Λ (s)=s^HΦ(s)s

Wherein,

So, problem can be written as：

3.2nd, due to P₂A biquadratic problem is still, is madeIt is a permanent mould coded sequence, furtherization Letter is：

Wherein,

Wherein, s^(m)It is the transmission signal after the m times outer iteration number of times, λ_maxThe eigenvalue of maximum of representing matrix Ψ；

Wherein, Vec () is represented and for each row order of matrix to be arranged as column vector；

3.3rd, due to P₃It is a s^(m+1)Quadratic power problem, for P₃By the way of by the N number of phase code of Meta Search Engine Solve, orderIt is a permanent mould coded sequence, can be written as：

Wherein,It is the transmission signal after i ＆ lt inner iterative number of times, calculates

The solution of above formula can be written as：

Wherein, symbol Arg () represents and takes angle, Υ (:, n) n-th row of representing matrix Υ (),Represent i ＆ lt Inner iterativeThe conjugation of vector；

3.4th, go out to meet the condition of convergence by 3.2 and 3.3 outwardly and inwardly iterative With | ρ_i-ρ_i-1| ＜ ε₁Transmission signal s^◇；

The permanent mould coding waveforms sequence s of step 4, transmitting optimization design^◇；

Step 5, radar reception processing, sample to radar return, and with design waveform signal s^◇To using signal Carry out matched filtering, output result.

By above step, it is possible to which it is J effectively to suppress transfer matrix_cSD interference, while can force down from phase Secondary lobe is closed, secondary lobe interference is reduced.

Innovative point of the invention is to suppress faster slower relay type using the Waveform Design mode of subpulse phase-modulation in arteries and veins SD types are disturbed.New target problem function model is initially set up, using suppressing cross-correlation between interference signal and transmission signal Thought sets up interference suppression signal model, considers to suppress signal autocorrelation side lobe levels simultaneously on the basis of interference is suppressed, and Consider permanent modular constraint, then proposing a kind of optimal minimum iterative search (MMIS) optimized algorithm carries out abbreviation solution.The party Method can well suppress the interference of SD types, especially fast relay type (within a PRT) electronic interferences, and can keep low side The radar detection requirement of valve, after disturbing transfer matrix to determine, even if there is (including the fast slow-speed of multiple interference or different delay Hair), without redesign waveform.

Brief description of the drawings

Fig. 1 is flow chart of the invention.

Fig. 2 is for using being not optimised, waveform is filtered with optimization Waveform Matching to emulate knot under single goal list SMSP disturbed conditions Fruit contrasts, and real goal signal to noise ratio is 10dB, and jamming-to-signal ratio is 20dB, and interference postpones as 0.3 μ s, PRT is 10 μ s.

Wherein：A () is that, using the reception matched filtering result of normal waveform, real goal is blanked, occur many False target；B () is the simulation result for having used optimization waveform, figure centre circle goes out spike as real goal, the void that interference is caused Decoy is suppressed.

Fig. 3 is for using being not optimised, waveform is filtered with optimization Waveform Matching to emulate knot under many SMSP disturbed conditions of multiple target Fruit contrasts, and each real goal signal to noise ratio is 10dB, and jamming-to-signal ratio is 20dB, and interference postpones as 0.3 μ s, PRT is 10 μ s.

Wherein：A () is that, using the reception matched filtering result of normal waveform, real goal is blanked, occur many False target；B () is the simulation result for having used optimization waveform, figure centre circle goes out the true mesh that spike is multiple different delays Mark, the false target that interference is caused is suppressed.

Specific embodiment

The main method using Computer Simulation of the invention is verified that all steps, conclusion are all in MATLAB-R2014a Upper checking is correct.Specific implementation step is as follows：

Step 1, initiation parameter：

Initialization system parameter includes：Subpulse number N=128 in arteries and veins, iteration convergence coefficient ε₁=10^-5, ε₂=10^-4, As a example by being disturbed using SMSP, sampling number is L=16, and number of repetition is q=8, so signal transfer matrix J_cFor

Step 2, set up optimization problem Mathematical Modeling：

2.1st, according to Waveform Design criterion 1) reduce integration cross-correlation level between interference signal and radar emission signal (Integrated Cross-correlation Sidelobe Level, ICSL) is set up with realizing suppressing interference signal

Wherein, ()^HRepresent conjugate transposition,It is mapping matrix.

2.2nd, according to Waveform Design criterion 2) the integration auto-correlation level of radar emission signal is reduced to force down integration secondary lobe Level (Integrated Auto-correlation Sidelobe Level, IASL), sets up

2.3rd, the criterion function according to 2.1,2.2 sets up following problem model：

Step 3, for problem P₁Solving-optimizing waveform：

3.1st, m=0, random initializtion perseverance mould transmission signal s are made⁽⁰⁾。

3.2nd, m=m+1 is made,

3.3rd, i=0, n=1 are made,

3.4th, i=i+1 is made,

3.5th, calculated by unit

3.6th, calculate,If | ρ_i-ρ_i-1| ＜ ε₁, 3.7 are carried out, otherwise, return to 3.4.

3.7th, makeCalculate Λ (s^(m)),

If the 3.8,Then carry out next step, otherwise return to step 3.2.

3.9th, the transmitted waveform s for being optimized^◇=s^(m),

The permanent mould coding waveforms sequence s of step 4, transmitting optimization design^◇。

Step 5, radar reception processing, sample to radar return, and with design waveform signal s^◇To using signal Carry out matched filtering, output result.

By above step, it is possible to which it is J effectively to suppress transfer matrix_cSD interference, while can force down from phase Secondary lobe is closed, secondary lobe interference is reduced.

In above-mentioned emulation, Fig. 2 and Fig. 3 sets forth for SMSP interference single goal go alone disturb, multiple target it is how dry Emulated in the case of disturbing, it can be seen that be easy to be disturbed using the radar signal for being not optimised waveform, and used optimization ripple Matched filtering result after shape shows that false target interference is effectively suppressed, and side lobe levels are also reduced, and real goal is easy to It is detected.

By specific implementation of the invention as can be seen that the present invention uses the Waveform Design side of subpulse phase-modulation in arteries and veins Formula suppresses the interference of faster slower relay type SD types.New target problem function model has been initially set up, one kind has then been proposed optimal most Smallization iterative search (MMIS) optimized algorithm carries out abbreviation solution.The method is in single goal list SD interference, many SD interference of multiple target In the case of, can well suppress single multi- SD types and disturb, and the radar detection requirement of low sidelobe can be kept, when interference is shifted After matrix determination, even if there is multiple interference or different delay (including speed forwarding), without redesign waveform.

Claims (1)

1. a kind of cognition perseverance mould waveform design method that antinoise signal dependent form is disturbed, the method includes：

Step 1, initiation parameter：

Initialization system parameter includes：Subpulse number N in arteries and veins, sets initial perseverance mould transmission signal s₀, s=[s₁, ...s_n,...,s_N] it is radar emission signal, whereinN=1 ..., N, wherein φ_nIt is s₀N-th subpulse Phase code；Interference signal transfer matrix J_c, then interference echo signal is c=J_cS, iteration convergence coefficient ε₁, ε₂；

Step 2, set up optimization problem Mathematical Modeling：

2.1st, set up to reduce and cross-correlation level ICSL (Integrated Cross- are integrated between interference signal and radar emission signal correlation Sidelobe Level)：

$ICSL=\underset{k=1}{\overset{N-1}{\Σ}}|s^H{J}_k^T{J}_{c}s{|}^2+\underset{k=0}{\overset{N-1}{\Σ}}|s^H{J}_k{J}_{c}s{|}^2$

Wherein, ()^HRepresent conjugate transposition,It is mapping matrix, k={ 0,1 ..., N-1 } is represented and postponed number；

2.2nd, the integration auto-correlation level of radar emission signal is set up to force down integration sidelobe level IASL (Integrated Auto-correlation Sidelobe Level)：

$IASL=2\underset{k=1}{\overset{N-1}{\Σ}}|s^H{J}_{k}s{|}^2$

2.3rd, the criterion function according to 2.1,2.2 sets up following problem model：

$P_1\left\{\begin{array}{cc}\underset{s}{\min }& \underset{k=1}{\overset{N-1}{\Σ}}|s^H{J}_k^T{J}_{c}s{|}^2+\underset{k=0}{\overset{N-1}{\Σ}}|s^H{J}_k{J}_{c}s{|}^2+2\underset{k=1}{\overset{N-1}{\Σ}}|s^H{J}_{k}s{|}^2\\ s.t.& \left|s_n\right|=\frac{1}{\sqrt{N}},n=1,\mathrm{...},N\end{array}\right.$

Step 3, for problem P₁Solving-optimizing waveform：

3.1st, abbreviation P first₁Optimization problem be：

Λ (s)=s^HΦ(s)s

Wherein,

$\mathrm{\Φ}\left(s\right)=\underset{k=1}{\overset{N-1}{\Σ}}(2J_k{\mathrm{ss}}^H{J}_k^T+J_k^T{J}_c{\mathrm{ss}}^H{J}_k^T{J}_k+J_k{J}_c{\mathrm{ss}}^H{J}_c^T{J}_k^T)+J_c{\mathrm{ss}}^H{J}_c^T$

So, problem can be written as：

$P_2\left\{\begin{array}{cc}\underset{s}{\min }& s^H\mathrm{\Φ}\left(s\right)s\\ s.t.& \left|s_n\right|=\frac{1}{\sqrt{N}},n=1,\mathrm{...},N\end{array}\right.$

3.2nd, due to P₂A biquadratic problem is still, is madeIt is a permanent mould coded sequence, further abbreviation is：

Wherein,

$\begin{array}{c}G\left(s^{\left(m\right)}\right)=\underset{k=1}{\overset{N-1}{\Σ}}\{2{\left(s^{\left(m\right)}\right)}^H{J}_k{s}^{\left(m\right)}{J}_k^T+{\left(s^{\left(m\right)}\right)}^H{J}_k^T{J}_c{s}^{\left(m\right)}{J}_c^T{J}_k+{\left(s^{\left(m\right)}\right)}^H{J}_k{J}_c{s}^{\left(m\right)}{J}_c^T{J}_k^T\}\\ +{\left(s^{\left(m\right)}\right)}^H{J}_c{s}^{\left(m\right)}{J}_c^T-{\mathrm{\λ}}_{\max }{s}^{\left(m\right)}{\left(s^{\left(m\right)}\right)}^H\end{array}$

Wherein, s^(m)It is the transmission signal after the m times outer iteration number of times, λ_maxThe eigenvalue of maximum of representing matrix Ψ；

$\begin{array}{c}\mathrm{\Ψ}=2\underset{k=1}{\overset{N-1}{\Σ}}Vec\left(J_k\right)Vec{\left(J_k\right)}^H+\underset{k=1}{\overset{N-1}{\Σ}}Vec\left(J_k^T{J}_c\right)Vec{\left(J_k^T{J}_c\right)}^H\\ +\underset{k=1}{\overset{N-1}{\Σ}}Vec\left(J_k{J}_c\right)Vec{\left(J_k{J}_c\right)}^H\end{array}$

Wherein, Vec () is represented and for each row order of matrix to be arranged as column vector；

3.3rd, due to P₃It is a s^(m+1)Quadratic power problem, for P₃Solved by the way of by the N number of phase code of Meta Search Engine, OrderIt is a permanent mould coded sequence, can be written as：

Wherein,It is the transmission signal after i ＆ lt inner iterative number of times, calculates

The solution of above formula can be written as：

Wherein, symbol Arg () represents and takes angle, Υ (:, n) n-th row of representing matrix Υ (),Represent inside i ＆ lt IterationThe conjugation of vector；

3.4th, go out to meet the condition of convergence by 3.2 and 3.3 outwardly and inwardly iterativeWith | ρ_i- ρ_i-1| ＜ ε₁Transmission signal；

The permanent mould coding waveforms sequence of step 4, transmitting optimization design；

Step 5, radar reception processing, sample to radar return, and with design waveform signalTo being carried out using signal With filtering, output result.