Re: [Discuss-gnuradio] misterious symetrical signal

[Tom Rondeau]

On Tue, Nov 27, 2012 at 8:31 AM, nexy_sm <address@hidden> wrote:

Hallo people,

During my adventure of designing 433MHz receiver i have recently discovered
misterious simetrical signal which I am not able to explain to myself. I am
using USRP1 with WBX daughter board. While observing complex baseband
signal, I realized that depenting on RF gain I have a signal simmetrical to
the transmitted signal. I have also attached a photo.

Hope that you have some explanation.

<http://gnuradio.4.n7.nabble.com/file/n38503/Screenshot.png>
<http://gnuradio.4.n7.nabble.com/file/n38503/Screenshot-1.png>

Looks like the effects of IQ imbalance.

I didn't read this closely, but this page looks like a pretty good explanation:

http://www.dsplog.com/2009/03/08/iq-imbalance-in-transmitter/

Tom