摘要
本文提出了一种设计宽带恒定束宽波束形成器的方法．这对应用于海底探测和分类问题的声纳系统来说是十分重要的．对于给定频带宽度的信号，选择一定数量的频率点来表达其频率响应．对于一个给定的频点，可以通过现有方法导出满足恒定束宽要求的加权矢量，例如对于一个线列阵，可用切比雪夫多项式得到其加权矢量．因此对于一个具有Ｎ个阵元的宽带阵，如果选择Ｍ个频率点，可以得到一个Ｎ·Ｍ的加权矩阵．这个矩阵的每一行代表一个阵元的频率响应，而这个频率响应可以由采用模型参考自适应方法设计的ＦＩＲ滤波器来实现．这样一组Ｎ个ＦＩＲ滤波器的输出之和就是波束形成的输出，它可以很方便地通过ＤＳＰ硬件来实现．本文给出了一个使用这种方法设计的例子，结果是令人满意的。
The paper presents a method to design a beamformer for broadband constant beamwidth. Such a beamformer is important in sonar systems for sea bottom observa- tion and classification applications. For a given frequency band, a number of frequency points are chosen to represent the response. For each frequency point a beamforming weighting vector can be deduced to satisfy a given beamwidth requirement by existing methods, for example the Chebyshev shielding coefficients can be deduced for a linear array. Therefore, for a broadband array of N elements and for M chosen frequency points, a N'M weighting matrix in which each row represents a frequency response of an array element, which can be satisfied by a FIR filter designed by the model-reference adaptive technique. The sum of outputs from a bank of N FIR filters provides a beamformed output and so it is very handy to be implemented by DSP hardware. A design example shows that the results are satisfactory.
出处
《应用声学》
CSCD
北大核心
1999年第5期29-33,共5页
Journal of Applied Acoustics
关键词
宽带恒
定束宽
波束形成器
FIR滤波器
声纳
Beamformer for broadband constant beamwidth, FIR filter, Model-reference adaptive technique
