中文摘要：

频率不变波束形成器（Frequency-invariant beamformer, FIB）在宽带声信号的无失真采集和处理中具有重要应用。基于空间响应变化函数的最小二乘方法是近年来FIB设计中的代表性方法，本文研究表明该方法的性能受频率不变波束形成（Finite impulse response，FIR）滤波器抽头长度的影响，增大抽头的长度可有效提高FIB设计的性能。但随滤波器抽头长度的增大，波束形成器的实现复杂度亦变大。针对这一问题，本文提出了一种基于FIR滤波器抽头稀疏化的最小二乘FIB设计方法，利用信号稀疏表示理论中的迭代加权z，范数优化实现了低复杂度最小二乘FIB设计，并通过设计实例验证了所提方法的有效性。

英文摘要：

The frequency invariant beamformer （FIB） is of great interest in practice for distor- tionless broadband audio signal acquisition and processing. One of the representative approa- ches recently proposed for FIB design is the least squares method based on the spatial response variation （LS-SRV）. It is noted that the performance of the LS-SRV is dependent on the tap length of finite impulse response （FIR）. By increasing the FIR tap length, the FIB perform- ance can be effectively improved. However, this is at the cost of greater implementation com- plexity. To combat this problem, an improved design scheme with sparse FIR tap coefficients is proposed. The proposed approach is based on the iterative reweighted minimization from sig- nal sparse representation. The efficacy of the proposed approach is evaluated by design exam- pies.