Acoustic Beamformer with a Constant Beamwidth for Planar Array

Oren at el [1] suggested a solution for designing an acoustic beam, with a constant beam width for a one-dimensional symmetric array. Using a linear array is limited as it does not take in to consideration vertical angels in the spectrum which there for does not cover many applications. We would like to expand the solution to a two-dimensional array which is unnecessarily symmetric. During this project, we have implemented an algorithm which is based on the development from the article "FIR-based symmetrical acoustic Beamformer with a constant beam width” by Oren Rozen et al. The algorithm which was developed in the article was based on the array’s symmetry and as the frequency increased less microphones remained active, specifically, the microphones that were farther from the symmetry point were muted in pairs. As in our case, the symmetry characteristic absents, we modified the algorithm and muted the microphone that was farthest from the reference point which was set in advance. Using MATLAB, we have examined our algorithm and performed several tested on the bi-dimensional asymmetric microphones array. The results showed we have managed to keep a fixed beam width over a wide of frequencies range. Our experiment showed that the SNR at the beamformer output is much better than output of a single microphone. , We also found an additional advantage of the algorithm, which is significant reduction of the reverberation level

Acoustic Beamformer with a Constant Beamwidth for Planar Array
Acoustic Beamformer with a Constant Beamwidth for Planar Array
Collaboration:

Israeli Police