mulitple wave functions

[Oli Oli Oxin Free]

How to multiply sin and cos wave functions together

[MikeS81]

Hi Oli,

if you have to waveforms and you want to multiply them, then you can use the multiply function.

Mike

[Jacco K]

Like this:

[Oli Oli Oxin Free]

Thanks a lot for replying

I'm completely lost. I'm have a DIFAR composite audio signal and i'm trying to demultiplex it to get the the components out of it. The components are the omni, N-S direction, E-W direction. How do i go about in Labview creating a demultiplexer. The audio signal is coming from a recorder connected to the computer through the mic jack. Any inputs to how to start a project like that would be really helpful. Thanks a lot for the help

[Oli Oli Oxin Free]

what I meant by sine and cos functions are; sin[(30*pi*t)+Ø] and same with cosine.

Thanks a lot for the reply guys

[Oli Oli Oxin Free]

any help would be greatly appreciated

Thanks again

[MattBradley]

OK, I'll give it a shot.  Not really familiar with DIFAR signals -- are they at different frequencies?

My first thought would be to take an FFT of the signal, separate it by the frequencies of interest, and then reconstruct each of the signals of interest.  But that won't work unless they are at different freqs.

-Matt

[Oli Oli Oxin Free]

thanks a lot for replying matt

yes the DIFAR audio signals are at different frequencies. I have a implementation of a fft already done. How would I separate the frequencies of interest and reconstruct them? 

There are three different signals in that signal that I need to pull out. So how would I separate frequencies?

Thanks in advance

Moe

[MattBradley]

The easiest way would be to use three bandpass filters (one for each frequency).  No need to do FFT's, but it would require that you know the frequencies of interest before hand.  So, do you know which freqs you want?

[Oli Oli Oxin Free]

I don't necessarly know the frequencies before hand. Thats why I need to do an FFT on it and then the peaks need to be filtered. So initially, the peaks of the FFT need to be identified first then get filtered.

Hope that kinda explains it

Thanks 

moe