CN-115694430-B - Passband response constraint self-adaptive airspace filter design method

Abstract

The invention provides a passband response constraint self-adaptive spatial filter design method, and belongs to the technical field of array signal processing. The invention restrains the response error of the pass band, minimizes the norm of the output array data and can directly give the optimal solution of the filter. The filter design method solves two technical problems that on one hand, target signals of a required detection passband can be reserved, errors of the target signals of the passband are controllable, other interference signals can be effectively restrained, and on the other hand, the design efficiency is high, and real-time signal processing is facilitated.

Inventors

• HAN DONG
• YANG MEIJIAO
• XU CHI
• WANG LIXIA
• HE YIN
• WANG YONGCHAO
• LIU CONG
• ZHANG KUN

Assignees

• 中国人民解放军海军大连舰艇学院

Dates

Publication Date

20260508

Application Date

20221028

Claims (1)

1. 1. A passband response constrained adaptive spatial filter design method, comprising the steps of: step 1, selecting a passband detection area theta P to be reserved, discretizing the passband detection area theta P into P directions to obtain corresponding plane wave incident azimuth angles theta p , p=1, & gt, P, obtaining corresponding direction vectors a (theta p ) and array manifold matrix V P ＝[a(θ 1 ),…,a(θ p ),…,a(θ P by using a signal incident model, and obtaining Step2, setting a passband response error constraint value xi; step 3, calculating covariance matrix C x ＝x(t)x H (t) by using the received array data x (t); Step 4, according to the formula Calculating to obtain optimal solution of adaptive spatial filter Wherein the optimal Lagrange multiplier From the formula And (5) determining.

Description

Passband response constraint self-adaptive airspace filter design method Technical Field The invention belongs to the technical field of array signal processing, and relates to a passband response error constraint adaptive spatial filter design method. Background Object detection based on a sensor array is an important means for improving the orientation and positioning accuracy of objects, and the sensor array receives data and often contains far field or near field strong interference. The influence of the interference of far and near field intensity leads to the reduction of the target orientation and positioning precision based on the sensor array and the reduction of the target reconnaissance recognition capability. The airspace matrix filtering technology is to design a passband and a stopband of a detection airspace and adopt a proper filter design method to realize the expected response effect of the airspace filter on the passband and the stopband. The filter matrix is multiplied with the array data received by the sensor to realize spatial filtering, and the stop band interference can be restrained through spatial filtering processing, and the useful signals of the pass band are reserved. Conventional spatial filter design techniques produce filter response effects specific to pass and stop bands, primarily through fixed pass and stop band division. When the intensity of interference in the space domain changes, the conventional spatial filter cannot adaptively adjust the suppression capability of the interference space domain according to the energy level of the interference. In prior art document 1, "spatial matrix filtering and application thereof" (Han Dong, zhang Haiyong. Scientific press, 2016.4), the design of discrete, weighted discrete, continuous filters is described in detail, and the design method is a conventional spatial filter design method. Prior art document 2 "adaptive spatial matrix filter design and target azimuth estimation", feng Jie, yang Yixin, sun Chao, system simulation report, 2007,19 (20): 4798-4802, and prior art document 3"Convex Optimization Based Beam-Space Preprocessing With Improved Robustness Against Out-of-Sector Sources",Hassanien A,Elkader S A,Gershman AB, et al, IEEE trans.signal Processing,2006,54 (5): 1587-1595, designed an adaptive spatial filter design method that constrains the response error for each azimuth of the passband and the response for a specific azimuth of the stopband. The passband and stopband settings are models of the array using far-field plane wave signals incident thereto. Namely, the target signal to be detected is positioned in the spatial passband of the far-field plane wave model, and the interference signal is positioned in the stopband of the far-field plane wave model. The method has the main defects that firstly, the incidence model of the interference signal is limited to plane wave incidence, and the applicability is not wide. The model does not consider the complexity of signal propagation, and when the noise is a near-field interference incidence model or a model after multipath incidence, the stop band design should be adapted to the interference space incidence response vector, rather than the plane wave direction vector. Secondly, the solution efficiency is low, the operand is large, and the timeliness is poor. The design method needs to be converted into a second order cone planning solution, and a concise optimal solution expression cannot be given, so that the practicability of the technology is also affected. Disclosure of Invention The invention aims to provide a passband response constraint adaptive spatial filter design method, and an optimal solution of a filter is directly given. The filter design method solves two technical problems that on one hand, the method can keep target signals of a required detection passband, enables errors of the target signals of the passband to be controllable and can effectively inhibit other interference signals, and on the other hand, the method is high in design efficiency and beneficial to real-time signal processing. The technical scheme of the invention is as follows: Assuming that s 1 (t) is a passband target signal, s 0 (t) is near field interference, far field other azimuth interference or interference signal via multipath superposition, n (t) is additive noise, the model of the array received data x (t) is as follows: x(t)=VPs1(t)+VSs0(t)+n(t) in the formula, Is an array manifold matrix formed by passband direction vectors, V P＝[a(θ1),…,a(θp),…,a(θP)],1≤p≤P,θp∈ΘP,ΘP represents the passband region where the direction vector is located, a (θ p) is the P-th direction vector after passband discretization, and P corresponds to the number of direction vectors after passband region discretization.Is an array manifold matrix formed by stop band response vectors, V S＝[v1,…,vs,…,vS, S is more than or equal to 1 and less than or equal to S, S is the number of stop band interference,