基于FIR滤波器的改进恒定束宽波束形成算法

Improved constant beamwidth beamforming algorithm based on FIR filter

摘要:

针对宽带信号中不同频率分量所对应的增益不同导致阵列接收信号产生失真的问题，提出了一种基于FIR滤波器的恒定束宽波束形成算法.该算法利用FIR滤波器阵列结构和麦克风均匀线阵列的对称属性，确定波束形成算法恒定束宽的频率范围并获得近似恒定束宽的阵列响应；针对相邻的截止频率之间波束宽度的波动较大问题，设计了参考波束并利用最小二乘法获得最优权值；最后对最优权值进行归一化处理，获得了均匀增益.仿真和实验验证了算法的有效性.

Abstract:

The gain of array receiving signal is distorted due to the different gain of different frequency components in wideband signal；in order to solve the problem, an algorithm is proposed to improve constant beamwidth beamformer based on FIR. In this algorithm, the FIR filter array structure and microphone uniform line array features are utilized to determine the frequency range of constant beamwidth beamformer and obtain the array response with a constant beamwidth. In addition, the reference beam is designed to deal with the large fluctuation of the beamwidth between the adjacent cutoff frequencies, and the least square method is used to find the optimal weight. Finally, the optimal weight is normalized to gain a uniform gain. Computer simulation and experimental results verify the effectiveness of the algorithm.