I/Q TO DBM

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pachoduran
Posts: 10
Joined: Fri Jun 10, 2016 10:21 pm

I/Q TO DBM

Postby pachoduran » Tue Jul 05, 2016 5:43 pm

Hi, i need obtain dbms using the API, i can obtain the signals I and Q, i can graphics this signals, but can't convert to dbms Signals. thanks
Last edited by pachoduran on Thu Jan 01, 1970 12:00 am, edited 0 times in total.
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marcozennaro
Posts: 1
Joined: Thu Jul 07, 2016 8:55 am

Re: I/Q TO DBM

Postby marcozennaro » Thu Jul 07, 2016 8:57 am

Hi! How did you obtain the signals I and Q? From command line? Thanks!
Last edited by marcozennaro on Thu Jan 01, 1970 12:00 am, edited 0 times in total.
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va2fsq
Posts: 7
Joined: Tue Mar 15, 2016 11:55 pm

Re: I/Q TO DBM

Postby va2fsq » Sat Jul 09, 2016 11:58 pm

Hi,
It's a little more complex. Basically you need to do the following:
Create an array of complex numbers using the I and Q
Feed this to a double sided FFT
Do a cartesian to polar conversion and then convert to dBm
Last edited by va2fsq on Thu Jan 01, 1970 12:00 am, edited 0 times in total.
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pachoduran
Posts: 10
Joined: Fri Jun 10, 2016 10:21 pm

Re: I/Q TO DBM

Postby pachoduran » Tue Jul 19, 2016 1:34 pm

Hi, thanks, i am probe your information, and is good. thanks
Last edited by pachoduran on Thu Jan 01, 1970 12:00 am, edited 0 times in total.
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pachoduran
Posts: 10
Joined: Fri Jun 10, 2016 10:21 pm

Re: I/Q TO DBM

Postby pachoduran » Tue Aug 02, 2016 11:11 pm

Im working with a wave generator with an frequency in MHZ. I want detect the wave genertor position with the information from the SDRplay device. I want see some variation in the magnitude when i analyze the SDRplay.

My first question is about the I and Q signals, im not sure with thats, due to i cant understand the signal. At the moment i takes both signals like a representation of the complex numbers. From the above, i understand it like the "I" signal represent the real part (I*Cos(2piFo)) and "Q" signal represent the imaginary part (Q*cos(2piFot)). The next step is create a new array with the both signals, and then obtain the FFT. The input to FFT is the array with I and Q and the output shows the spectrum of the signal. From the above i applied the conversion between cartesian to polar form due to i interest in the magnitude variation. Is it right?

When i analyze the spectrum signal, i can see some variation in the magnitude but it is so short so it is hard to meassure. Are you know why occurs it?

My third question is about the noise in the signals. can i remove it with some api command? .. I think that noise is mixed with the signal because i see many armonics in the spectrum signal and if i can remove it, maybe i can increases the magnitude variation. Is it available?

Thanks for you help.

Regards!
Last edited by pachoduran on Thu Jan 01, 1970 12:00 am, edited 0 times in total.
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