I added some attenuation. The overload is gone but the condition persists.
Thanks, Mike From: Brian Padalino <bpadal...@gmail.com> Sent: Wednesday, May 8, 2019 4:37 PM To: Michael Deacon <micha...@sysware.com> Cc: usrp-users@lists.ettus.com Subject: Re: [USRP-users] Relationship between IQ values, gain and noise on B205mini transmitter On Wed, May 8, 2019 at 7:28 PM Michael Deacon via USRP-users <usrp-users@lists.ettus.com <mailto:usrp-users@lists.ettus.com> > wrote: Hello, I have a simple transmitter consisting of a file source connected to a USRP sink (attached image radio.png). The file contains interleaved floating point IQ representing a few seconds of LTE. The IQ amplitude values are normalized between +1.0 and -1.0. The sink is configured to 60db, 7.5MHz sample rate, 385MHz center frequency and 5MHz bandwidth. The output looks exactly like the original on a spectrum analyzer (see attached good.jpg). If I turn up the gain on the sink or increase the amplitude of the IQ data I get what looks to be noise on either side of the signal spectrum (see attached bad.jpg). Any idea what is going on here? Your bad.jpg picture has the spectrum analyzer saying OLVD. Try changing your reference level of the spectrum analyzer to be higher so you don't saturate the input of the spectrum analyzer. Tell us if that fixes it for you. Brian
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