基于共轭梯度加速的自适应二次约束零陷展宽方法研究  

Adaptive Quadratic Constraint Null Broadening Method Accelerated by Conjugate Gradient

作　　者：高志奇[1,2] 张恩赏 黄平平 GAO Zhiqi;ZHANG Enshang;HUANG Pingping(College of Information Engineering,Inner Mongolia University of Technology,Hohhot,Inner Mongolia 010051,China;Inner Mongolia Key Laboratory of Radar Technology and Application,Hohhot,Inner Mongolia 010051,China)

机构地区：[1]内蒙古工业大学信息工程学院,内蒙古呼和浩特010051 [2]内蒙古自治区雷达技术与应用重点实验室,内蒙古呼和浩特010051

出　　处：《信号处理》2025年第4期595-608,共14页Journal of Signal Processing

基　　金：国家自然科学基金(61761037);内蒙古自治区自然科学基金项目(2021MS06005);内蒙古自治区直属高校基本科研业务费项目(JY20220147)。

摘　　要：雷达、声呐和无线通信等应用对于自适应波束形成的抗干扰能力和实时性提出了更高的要求。传统基于最速迭代的自适应波束形成算法存在“过拟合”特性,导致在相干干扰条件下的干扰抑制性能急剧下降。另外,当干扰存在扰动且导向向量失配时,也无法有效抑制干扰。针对上述问题,本文提出了一种基于共轭梯度(Conjugate Gradient,CG)加速的二次约束宽零陷干扰抑制自适应波束形成方法。该方法首先利用CG算法的快速收敛特性,完成采样协方差矩阵与导向向量间线性方程组的求解;其次将CG算法输出的权矢量作为迭代最速波束形成方法的初始权值,利用该方法的“过拟合”特性,确保对期望信号的强锁定;最后提出了一种强化干扰特征的波达方向(Direction of Arrival,DOA)估计方法,实现宽带相干干扰下的干扰来波方向估计,并将该方法与二次约束零陷展宽方法结合,用于捕获干扰特征,形成自适应零陷。仿真实验验证了所提方法在单快拍、宽带相干干扰条件下,能够自适应抑制干扰且稳健性较好。Applications such as radar,sonar,and wireless communications have heightened demands for improved anti-jamming capabilities and real-time performance in adaptive beamforming.Traditional adaptive beamforming algorithms that rely on the steepest descent method often exhibit an“overfitting”characteristic,which hinders their ability to effectively suppress interference.Furthermore,these algorithms struggle to manage interference when it involves perturbations and mismatches in the steering vector.To tackle these challenges,this paper proposes a quadratic constraint-wide nulling interference suppression method for adaptive beamforming,accelerated by the conjugate gradient(CG)algorithm.The proposed method first utilizes the rapid convergence properties of the CG algorithm to solve the linear equations relating the sample covariance matrix to the steering vector.The weight vector generated by the CG algorithm serves as the initial weight for the steepest descent beamforming method,leveraging the“overfitting”characteristic to ensure robust locking onto the desired signal.Additionally,we propose a direction of arrival(DOA)estimation method to enhance interference feature extraction,enabling the estimation of interference arrival directions in the presence of wideband coherent interference.This method works in conjunction with the quadratic constraint null broadening technique to capture and adaptively nullify interference characteristics.Simulation experiments confirm that the proposed algorithm efficiently adapts to suppress interference under both single snapshot and wideband coherent interference conditions while demonstrating strong robustness.

关 键 词：单快拍 宽带相干信号 自适应波束形成 零陷展宽 

分 类 号：TN958.92[电子电信—信号与信息处理]