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I/Q TO DBM

Posted: Tue Jul 05, 2016 5:43 pm
by pachoduran
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

Re: I/Q TO DBM

Posted: Thu Jul 07, 2016 8:57 am
by marcozennaro
Hi! How did you obtain the signals I and Q? From command line? Thanks!

Re: I/Q TO DBM

Posted: Sat Jul 09, 2016 11:58 pm
by va2fsq
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

Re: I/Q TO DBM

Posted: Tue Jul 19, 2016 1:34 pm
by pachoduran
Hi, thanks, i am probe your information, and is good. thanks

Re: I/Q TO DBM

Posted: Tue Aug 02, 2016 11:11 pm
by pachoduran
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!