基于变步长SOCP的宽带发射鲁棒唯相位ADBF算法

Wideband Transmit Robust Phase-only ADBF Algorithm Based on Variable Step-size SOCP

针对宽带自适应发射数字波束的权矢量非恒模、高动态环境下干扰抑制能力下降的问题,提出了一种基于变步长迭代二阶锥(Second-Order Cone Programming, SOCP)的宽带发射鲁棒唯相位自适应波束形成(Adaptive Digital Beam Forming, ADBF)算法。采用抽头延迟线结构(Tapped Delay Line, TDL)并结合多相滤波器(Polyphase Filter, PF)对宽带信号进行子带划分;在各子带内联合多线性约束最小方差(Multiple Linear Constrained Minimum Variance, MLCMV)准则与零陷展宽算法求解鲁棒权矢量;构建小相位扰动模型,引入变步长SOCP算法求解唯相位权矢量;最后通过综合滤波器进行子带综合,形成宽带发射波束。仿真结果表明,该算法可有效展宽干扰零陷,显著提高收敛性,且易于工程实施。

Wideband adaptive transmit digital beam has the problems that the weight vectors are not constrained by the constant modulus,and the interference suppression ability is degraded under high dynamic environment.So the wideband robust transmit phase-only Adaptive Digital Beam Forming(ADBF)algorithm based on variable step-size iterative Second-Order Cone Programming(SOCP)is proposed.In the algorithm,Tapped Delay Line(TDL)structure and polyphase filters are used to divide the wideband signals into sub-bands.Multiple Linear Constrained Minimum Variance(MLCMV)criterion and null broadening algorithm are combined to compute the robust weight vector in each sub-band.Then a small-phase-perturbation model is constructed,and the variable step-size SOCP algorithm is introduced to calculate the phase-only weight vector.Finally,the wideband transmit adaptive beam is reconstructed through the synthesis filters.Simulation results show that the algorithm effectively broadens the interferencenull,significantly improves the convergence,and is easy to be implemented in engineering applications.