phased.Sub​bandMVDRBe​amformer for microphone array

I want to implement a MVDRBeamformer for an microphone array. But it is required to set the property 'OperatingFrequency'. In the microphone array case, the signals are not modulated so I do not need to set the operating frequency. How can we solve this problem? Is this not suited for acoustic beamforming?

Thanks. Best Regards, Jiwon

[Elisabeth van Pruissen]

Hi Jiwon,

I was wondering if you managed to solve this problem since I want to apply MVDR to acoustic beamforming as well. Maybe you have some tips for me.

Thanks, Elisabeth

Answer 1

[Honglei Chen]

I would recommend you to look at Frost beamformer which is a time domain implementation. This beamformer works for both narrowband and wideband signals as well as modulated or unmodualted signals. The underneath theory is similar to MVDR.

https://www.mathworks.com/help/phased/ref/phased.frostbeamformer-system-object.html

HTH

Answer 2

[Ankit Bhatnagar]

Hi,

There is a default value for the Operating frequency as 300.0e6 Hz, if you don not want to provide one. For more information or similar examples check:

• https://www.mathworks.com/help/phased/ref/mvdrbeamformer.html#bvncpyl-7

If you are referring to the simulation of the far field for an acoustic signal, At far field, the propagation of sound wave is similar to the propagation of electromagnetic waves. However, the simulation in the toolbox assumes the signal is modulated at a carrier. It cannot simulate the attenuation of an acoustic signal during to propagation based on standard 1/r losses, humidity, and frequency.