频率不变宽带波束形成权重系数的稀疏优化

Sparse optimization for weight coefficient of wideband frequency invariant beamforming

在基本的傅里叶变换频率不变波束形成(FIB)基础上,从减少抽头权重系数数量,降低FIB运算量角度出发,提出基于最小l0范数的抽头权重系数稀疏优化模型,并采用正交匹配追踪(OMP)算法来求解该优化问题。在高增益、等波纹、低旁瓣FIB方向图的要求下,所提出的优化方法使得稀疏率降低到3.53%,且能够保证稀疏优化后的方向图误差小于1%。接着进一步开展阵元数量的稀疏优化,有效地减少了阵元通道数,进一步降低了算法实现的硬件复杂度。仿真结果验证了所提方法的正确性和有效性。

To reduce the computational complexity of the basic Fourier transform frequency invariant beamforming（FIB）,the sparse optimization for tap weights of the FIB is proposed based on minimuml 0 norm.The optimization is solved by the orthogonal matching pursuit（OMP）.,With the proposed method,the sparse rate of the effective tap weights decreases to 3.53% when the relative error of the FIB beam pattern is less than 1%.At the same time,the beam patterns of FIB synthesized by sparse tap weights can hold high gain,equiripple and low sidelobes.To reduce the number of tapped delay lines（TDLs）,the sparse optimization for the TDLs is also presented,which effectively decreases the number of sensor elements,and reduces the implementation complexity.The simulation results verify the correctness and effectiveness of the proposed method.