Applying complex weight to real data for beamforming!

"Stan Pawlukiewicz" <spam@spam.mitre.org> wrote in message 
news:dmpmos$rsr$1@newslocal.mitre.org...
> tamero wrote:
<snip>
>>>Application: Implement a broadband beamformer for acoustic interference
>>>cancellaion on TI chip.
>>>Reference: Kevin Buckley's "Beamforming: A Versatile approach to spatial
>>>filtering"
>>>
<snip>

I suspect that broadband means use time delay - no problem now with your 
real signals.

Best of luck - Mike

As a generally rule, the phase difference between receivers in an array of 
sensors is small compared to the phase difference caused by their difference 
in location relative to the incoming wavefront.  Your general choices are 
using time delays if you stay in the time domain or complex weights 
corresponding to delays in the frequency domain.  Your narrow band signals are 
complex when converted to narrowband digital samples.


In article <d56dnTkbcLJlyQ3eRVn-jw@giganews.com>, "tamero" 
<ozgur.tamer@gmail.com> wrote:
>>Hi, 
>>
>>I am very inexperienced in the area of beamforming and applied DSP. I
>was
>>wondering if you can help with some basic questions. 
>>
>>Application: Implement a broadband beamformer for acoustic interference
>>cancellaion on TI chip.
>>Reference: Kevin Buckley's "Beamforming: A Versatile approach to spatial
>>filtering"
>>
>>Question: 
>>> Most of the beamforming techniques presented requires applying a
>complex
>>weight to the data(which is real). I am sure that there is a simple way
>to
>>do that but i can't get it right ( i am trying with the simple
>narrowband
>>case first). Can anyone help me?
>>
>>> For the constrained LCMV with GSC. Can you tell me if it for broadband
>>signal?
>>
>>Thanks a lot for the help. 
>>
>>- Vik
>>
>>
>>               
>>This message was sent using the Comp.DSP web interface on
>>www.DSPRelated.com
>>
>
>Hi Vik,
>If you have one receiver receiving a real data then we can assume the
>signal is real i guess. but when we have multiple receivers for
>beamforming  then we can not model the received signals as real because of
>the phase differences between the receivers. so for multiple receiver
>systems even if the signals are real independently they are complex when
>they perform as an array. I hope this helps about your confusion.
>Ozgur
>
>